REVIEWED PLN BLD2023-1134+Geotechnical_Report+9.8.2023_3.09.41_PM+3773001Geotechnical Report
Meadowdale Beach
RECEIVED
Park and Estuary Restoration
Sep 08 2023 BLD2023-1134 Snohomish County, Washington
CITY OF EDMONDS
DEVELOPMENT SERVICES
DEPARTMENT February 16, 2018
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Reviewed by
City of Edmonds ;
Planning Division
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GEOTEONNICAI AN13 ENVINONMENTAI CONSUITANTS
Excellence. Innovation. Service. Value.
Since 1954.
Submitted To:
Snohomish County Parks & Recreation
Attn: Ms. Logan Daniels, PE
6705 Puget Park Drive
Snohomish, Washington 98296
By:
Shannon & Wilson, Inc.
400 N 34t" Street, Suite 100
Seattle, Washington 98103
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SHANNON 6WILSON, INC.
TABLE OF CONTENTS
Page
1.0 INTRODUCTION.................................................................................................................. I
2.0 SITE AND PROJECT DESCRIPTION.................................................................................1
2.1 Meadowdale Beach Park............................................................................................1
2.2 Lund's Gulch..............................................................................................................2
2.3 Historic Meadowdale Country Club..........................................................................2
2.4 BNSF Railway Company (BNSF) Embankment.......................................................2
2.5 Proposed Estuary Restoration Project........................................................................3
4.0 SUBSURFACE EXPLORATION.........................................................................................3
4.1 Access Road Borings.................................................................................................4
4.2 Bridge Borings...........................................................................................................4
4.3 Infiltration Potential Hand Borings............................................................................4
4.4 Horizontal Embankment Boring................................................................................4
4.5 Test Pits......................................................................................................................5
5.0 LABORATORY TESTING...................................................................................................5
6.0 GEOPHYSICAL SURVEYS.................................................................................................5
6.1
Ground Penetrating Radar (GPR)...............................................................................6
6.1.1 Park Lawn Area Ground Penetrating Radar (GPR) Survey .........................6
6.1.2 BNSF Railway Company (BNSF) Embankment Ground Penetrating
Radar(GPR) Survey....................................................................................6
6.2
Electrical Resistivity Tomography(ERT)..................................................................7
7.0 GEOLOGY
AND SUBSURFACE CONDITIONS...............................................................8
7.1
Regional Geology.......................................................................................................8
7.2
Geologic Setting.........................................................................................................8
7.3
Geologic Units and Generalized Subsurface Conditions...........................................9
7.3.1 Geologic Units.............................................................................................9
7.3.1.1 Fill (Hf).......................................................................................9
7.3.1.2 Alluvium/Colluvium (Ha/Hc)...................................................10
7.3.1.3 Whidbey Formation (Qpnf and Qpnl).......................................10
7.3.2 Subsurface Conditions...............................................................................11
7.3.2.1 Whidbey Formation Density.....................................................11
7.3.2.2 Railroad Embankment Fill........................................................11
7.3.2.3 Buried Manmade Debris...........................................................12
7.4
Groundwater.............................................................................................................12
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Page
8.0 ENGINEERING CONCLUSIONS AND RECOMMENDATIONS..................................13
8.1
Design Standards......................................................................................................13
8.2
Seismic Design.........................................................................................................13
8.2.1 Site Class....................................................................................................13
8.2.2 Railroad Bridge Seismic Design Parameters.............................................14
8.2.3 Pedestrian Bridge Seismic Design Parameters..........................................14
8.2.4 Liquefaction Potential................................................................................15
8.2.4.1 Railroad Bridge Liquefaction Potential....................................15
8.2.4.2 Pedestrian Bridge Liquefaction Potential..................................15
8.3
Railroad Bridge Design............................................................................................16
8.3.1 Driven Pile Foundations............................................................................16
8.3.2 Lateral Earth Pressures..............................................................................17
8.3.2.1 Railroad Bridge Temporary Shoring.........................................17
8.3.2.2 Temporary Shoring Wall Anticipated Movements ...................18
8.3.3 Bridge Abutments......................................................................................18
8.3.4 Permanent Slopes.......................................................................................19
8.3.5 Retaining Wall at Pedestrian Path..............................................................19
8.4
Pedestrian Bridge.....................................................................................................20
8.4.1 Bridge Abutment Foundations...................................................................20
8.4.2 Lateral Earth Pressure................................................................................21
8.4.2.1 Existing Condition Static.......................................................21
8.4.2.2 Existing Condition — Seismic....................................................22
8.4.2.1 Mitigated Condition Static.....................................................22
8.4.2.2 Mitigated Condition — Seismic.................................................23
8.4.3 Approach Fill Wingwalls...........................................................................23
8.4.4 Diamond Pier ® Boardwalk Foundations..................................................24
8.5
Lateral Pile Analysis................................................................................................24
8.6
Restroom Enclosure Foundations.............................................................................25
8.6.1 Bearing Capacity........................................................................................25
8.6.2 Slab-on-Grade............................................................................................26
8.7
Access Road Stability Improvements......................................................................26
8.7.1 Back-Calculation........................................................................................27
8.7.2 Anticipated Equipment Surcharge.............................................................28
8.7.2.1 Dump Truck Surcharge.............................................................28
8.7.2.2 Crawler Crane Surcharge..........................................................28
8.7.3 Proposed Access Road Stability Improvement..........................................28
8.8
Site Preparation........................................................................................................29
8.9
Compaction, Structural Fill Placement, and Use of On -site Soils ...........................30
9.0 CONSTRUCTION CONSIDERATIONS...........................................................................31
9.1 Temporary Excavation Slopes.................................................................................31
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Page
9.2 Driven Piles..............................................................................................................32
9.2.1 General.......................................................................................................32
9.2.2 Obstructions...............................................................................................32
9.3 Construction Impacts to Railroad Tracks.................................................................32
9.4 Embankment Excavation and Shoring Monitoring..................................................32
9.5 Wet Weather Earthwork...........................................................................................33
9.6 Erosion Control........................................................................................................34
10.0 ADDITIONAL SERVICES.................................................................................................34
11.0 LIMITATIONS....................................................................................................................34
12.0 REFERENCES.....................................................................................................................37
TABLES
1 AREMA 2016/ASCE 7-10 Parameters for Seismic Design of Structures Site
Class E
2 Recommended L-Pile Parameters
FIGURES
1 Vicinity Map
2 Site and Exploration Plan
3 Test Pit Locations and GPR Results —Park Lawn Area
4 Generalized Subsurface Profile A -A'
5 Section View at Horizontal Boring Location
6 GPR Profiles with Horizontal Boring Location
7 Inverted Resistivity Profiles with Horizontal Boring Location
8 Estimated Axial Capacity — HP 14X89 Driven Pile — Boring MB-6
9 Estimated Axial Capacity — HP 14X89 Driven Pile — Boring MB-7
10 Recommended Lateral Earth Pressures for Temporary Walls
11 Recommended Surcharge Loading for Temporary and Permanent Walls
12 Estimated Axial Pile Resistance, 2-Inch-Diameter Pin Pile, Boring MB-8
13 Estimated Axial Pile Resistance, 4-Inch-Diameter Pin Pile, Boring MB-8
14 Estimated Axial Pile Resistance, 6-Inch-Diameter Pin Pile, Boring MB-8
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TABLE OF CONTENTS (cont.)
APPENDICES
A Subsurface Explorations
B Geotechnical Laboratory Testing
C Geophysical Surveys
D Historical Research
SHANNON WLSON, INC.
E Important Information About Your Geotechnical/Environmental Report
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GEOTECHNICAL REPORT
MEADOWDALE BEACH
PARK AND ESTUARY RESTORATION
SNOHOMISH COUNTY9 WASHINGTON
1.0 INTRODUCTION
This report presents geotechnical engineering conclusions and recommendations for the
proposed Meadowdale Beach Park and Estuary Restoration Project near Edmonds, Washington.
The project location is shown in the Vicinity Map, Figure 1. This report includes a summary of
surveys and explorations, subsurface conditions, and the results of engineering studies and
analyses. Our scope of services consisted of site reconnaissance, two geophysical surveys,
drilling and sampling ten borings, excavating five test pits, laboratory testing, geotechnical
engineering studies, and preparation of this report. Our services were authorized via contract
between Snohomish County and Shannon & Wilson, Inc., dated August 25, 2016, and via Task
Assignment TA#3 issued through On -Call Contract OCC15/1-9(AN) between Snohomish
County and Shannon & Wilson. Our services were provided in general accordance with our
proposals dated July 25, 2016, and June 1, 2016
Per direction received during a May 16, 2017, phone conversation with Ms. Logan Daniels of
Snohomish County Parks and Recreation, this report includes scope items identified in both the
July 25, 2016, and June 1, 2016, proposals.
Our July 25, 2016, scope of services includes several tasks associated with planning and
designing a shoofly to bypass the construction site. During preliminary design review, BNSF
Railway Company (BNSF) stated they would not allow a shoofly. Subsequent exploration and
design efforts have excluded shoofly elements, and there are no discussion or recommendations
regarding shoofly elements in this report.
2.0 SITE AND PROJECT DESCRIPTION
2.1 Meadowdale Beach Park
Meadowdale Beach Park is located on the north boundary of Edmonds, Washington, as shown in
the Vicinity Map, Figure 1. The southwestern portion of the site, approximately defined as the
area west of where 691h Avenue West would intersect Lunds Gulch Creek, and south of where
1541h Street West would cross through the park, is within the Edmonds city limits. The park
areas north and east of those approximate boundaries are in unincorporated Snohomish County.
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The park is accessible via a gated road (Figure 2), which extends north from 75th Place West.
North of the park entrance gate, the road continues in a northern direction, paralleling Puget
Sound shoreline and a west -facing coastal bluff for about 400 feet before turning sharply to the
east and descending the north -facing slope of Lund's Gulch. At the toe of this steep hillside is a
hairpin turn sharply to the west to a parking lot. The park ranger's residence and a grass -covered
playfield with picnic shelters are located west of the parking lot. The western edge of the
playfield is bounded by an approximately 10-foot-high BNSF embankment.
2.2 Lund's Gulch
Meadowdale Beach Park occupies approximately the lower half of Lund's Gulch, which is an
approximately 1.5-mile-long, west -northwest -oriented drainage from uplands to Puget Sound,
through which Lund's Gulch Creek flows. Topographic relief is approximately 450 feet between
the upland park entrance at the terminus of 162nd Place SW and the Puget Sound shoreline.
Slope angles vary throughout Lund's Gulch, with localized areas of near -vertical bluffs and
nearly horizontal creek banks. The majority of the slopes along the north and south valley walls
are 3 Horizontal to 1 Vertical (3H:IV) or steeper and the valley bottom near the creek is flatter.
The park is heavily vegetated with low brush, alder, and scattered conifers. Lund's Gulch Creek
flows through a concrete box culvert under the BNSF embankment, across a sandy delta to Puget
Sound.
2.3 Historic Meadowdale Country Club
The project site was once owned by the Meadowdale Country Club, which constructed a
clubhouse and other buildings, sports courts, and a swimming pool in the area now occupied by
the grass playfield. The club closed in the late 1960s after repeated landslides damaged the
access road. A landslide initiated from the southern access road in 1967 destroyed the
clubhouse, according to resident Park Ranger, Doug Dailer (Pers. Comm., 2014). The
clubhouse was destroyed by fire in 1970, and in 1971 Snohomish County Parks acquired the
property for developing a park with beach access. Anecdotal accounts of early park
development indicate the clubhouse and other structures were demolished and placed within the
swimming pool then buried in place (Anchor, 2017).
2.4 BNSF Railway Company (BNSF) Embankment
The western limit of the grassy playfield is bounded by the BNSF embankment, which separates
the park area from the beach west of the embankment. The embankment is between about seven
and ten feet tall, and is bounded north and south by the valley walls of Lunds Gulch. The east
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embankment slope is inclined at approximately 2H:IV, with railroad ballast covering the surface
throughout the upper half, and vegetation covering the lower half. The west embankment slope
is inclined at approximately 1.5H:1 V or steeper, with riprap covering the surface. Brush and
trees are present along much of the riprap slope.
2.5 Proposed Estuary Restoration Project
The proposed estuary restoration includes replacing the existing concrete culvert through the
BNSF embankment with a multi -span bridge, and site grading to lower the ground surface
elevation and reestablish estuary habitat within the western portion of the grassy playfield. It
also includes construction of a new pedestrian bridge and construction of a new restroom
enclosure. The pedestrian path will include a new, Americans with Disabilities Act -accessible
route to the beach beneath the proposed bridge.
3.0 PREVIOUS STUDIES
Shannon & Wilson previously produced the following reports for this project:
Meadowdale Beach Park Geotechnical Feasibility Study, Geologic Assessment, and
Sediment Loading (Shannon & Wilson, 2015).
■ Meadowdale Beach Park Feasibility Study, Preliminary Geotechnical Assessment
Addendum (Shannon & Wilson, 2016).
Meadowdale Beach Park Estuary Restoration Project, Geologically Hazardous Areas
(Shannon & Wilson, 2017).
4.0 SUBSURFACE EXPLORATION
The field exploration program consisted of separate mobilizations to support different
geotechnical design elements. The exploration program consisted of drilling and sampling
eleven borings and excavating and sampling five test pits. Project archaeologists were on site to
observe soils in select explorations on the valley bottom. The soil borings were drilled during
the following mobilizations:
■ The access road mobilization included five soil borings along the access road,
■ The bridge borings mobilization included two soil borings near the proposed railroad
bridge abutments and one soil boring near the proposed pedestrian bridge,
■ Infiltration design borings included two shallow hand borings,
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The embankment boring mobilization included one horizontal boring into the railroad
fill, and
■ The test pit mobilization included five test pit excavations throughout the eastern
portion of the grassy playfield.
The locations of completed explorations are shown in Figures 2 and 3. Appendix A describes
the field methods used to advance the borings and excavate the test pits. Logs of the borings and
test pits are included in Appendix A.
4.1 Access Road Borings
Cascade Drilling completed five soil borings along the access road, designated MB-1 through
MB-5, from November 21 to 23, 2016. These borings ranged in depth from 40 to 60 feet. The
purpose of the access road borings was to characterize roadway fill for use in stability analyses to
evaluate the need for stability improvements under construction loading.
4.2 Bridge Borings
Holt Services, Inc. (Holt) completed three soil borings, designated MB-6 through MB-8, between
April I I and 21, 2017. Boring depths at MB-6 and MB-7, near the proposed railroad bridge
abutments ranged from 120 to 130 feet. Holt drilled boring MB-8, near the proposed pedestrian
bridge, to a depth of 25 feet. Project archeologists observed samples and cuttings from the start
of drilling until glacially deposited soils were encountered in these borings. The purpose of the
bridge borings was to characterize subsurface conditions for use in bridge foundation design.
4.3 Infiltration Potential Hand Borings
Shannon & Wilson staff advanced two hand borings, designated HB-1 and HB-2, on March 16,
2017. Boring depths at HB-1 and HB-2, at the east end of the playfield and parking lot,
respectively, ranged from 6 to 10 feet. Shannon & Wilson staff installed open standpipe
piezometers in these borings to monitor groundwater levels. The purpose of the infiltration
potential hand borings and subsequent groundwater level readings was to evaluate infiltration
potential as part of on -site stormwater infiltration design.
4.4 Horizontal Embankment Boring
Kulchin Foundation Drilling Company completed a single, approximately horizontal (5°
declination), exploratory boring (Figure 5), at the approximate location shown in Figure 2, on
June 12, 2017. The boring was advanced 37 feet though existing railroad embankment fill.
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Project archeologists observed utility clearing excavation. The primary purpose of the horizontal
embankment boring was to investigate the presence or absence of anomalies interpreted to be
present based on geophysical surveys as described in Section 6.0. Anticipated potential
anomalies included timber pile, boulders, buried timber bulkhead or rock seawall. The
horizontal embankment boring also allowed us to characterize the embankment fill for evaluating
pile driving conditions, shoring design, and embankment deconstruction planning.
4.5 Test Pits
Clear Creek Contractors, Inc. completed five test pit excavations, designated TP-1, TP-2, TP-3,
TP-B, and TP-RE-1, at the approximate locations shown in Figure 3, on July 20, 2017. Test Pit
excavations ranged in depth from 6 to 10.5 feet in depth. Project archeologists were present to
observe test pit excavations. The purpose of test pits TP-1, TP-2, TP-3, and TP-B was to
evaluate the presence or absence, and nature of anomalies interpreted from the geophysical
survey described in Section 6.0. Anticipated potential anomalies included concrete slabs, walls,
other manmade structures, or construction debris. The purpose of test pit TP-RE-1 was to
characterize subsurface conditions to support proposed restroom enclosure design.
5.0 LABORATORY TESTING
We performed geotechnical laboratory testing on select samples retrieved from the explorations
to evaluate index and engineering properties of the soil. Testing was performed in the Shannon
& Wilson laboratory in Seattle, Washington, and included visual classification, water content,
grain size analyses, and Atterberg limits. Soil testing was performed in general accordance with
ASTM International (ASTM, 2014) standard test procedures. Detailed descriptions of testing
methods and results are presented in Appendix B and shown graphically in the boring logs in
Appendix A.
6.0 GEOPHYSICAL SURVEYS
Global Geophysics performed a geophysical survey throughout the lawn area between the Park
Ranger's residence and the BNSF embankment, and another geophysical survey along the BNSF
embankment. The geophysical survey throughout the lawn area occurred in two phases; the
initial survey was completed on November 8, 2016, (Global Geophysics, 2016). The
supplemental survey was completed on January 20, 2017, (Global Geophysics, 2017a). The
geophysical survey along the BNSF embankment was completed on April 11 and 12, 2017,
(Global Geophysics, 2017b). The geophysical survey transect locations are shown in Figures 2
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and 3. Global Geophysics provided reports for each survey area, which describe the methods
employed and present interpreted data plots (Appendix Q.
6.1 Ground Penetrating Radar (GPR)
The GPR method uses electromagnetic pulses, emitted by an antenna, to penetrate the subsurface
soils. The electromagnetic pulses are reflected by objects or materials whose electrical
properties are different from the surrounding soil. The reflected electromagnetic pulses are
received by an antenna and recorded. The emitting and receiving antennae are housed within a
single unit whose position is tracked as the data is being collected, such that GPR results can be
located spatially within the survey area. GPR data is typically collected along linear transects
which are closely spaced such that plotted output represents nearly complete coverage of the
study area.
6.1.1 Park Lawn Area Ground Penetrating Radar (GPR) Survey
The initial GPR survey utilized onboard global positioning system (GPS) methods to
collect transect spatial data. Due to poor satellite visibility at the site, the accuracy of GPS
position data was poor and the spatial component of the GPR data was deemed unreliable. A
supplemental survey utilized conventional land surveying methods to measure and collect the
transect alignments and endpoints as shown in Figure 2. The results of the supplemental GPR
survey are shown in Figure 4.
The purpose of the lawn area GPR survey was to identify anomalies along each transect,
and locations where anomalies were concentrated or clustered. Anticipated potential anomalies
included manmade features such as concrete slabs and walls, foundation elements, and
demolition debris, as well as natural features such as cobbles, boulders, and logs, among others.
As indicated in Figure 3, the supplemental GPR survey detected numerous anomalous
features throughout the grassy park area, with apparent concentrations of anomalous features at
several locations along the northern leg of the asphalt walk, within the grassy area and just north
of the picnic area canopy.
6.1.2 BNSF Railway Company (BNSF) Embankment Ground Penetrating Radar
(GPR) Survey
We collected GPR data along four transects located along the top of the BNSF
embankment and oriented approximately parallel to the rails (Figure 2). The purpose of the
embankment GPR survey was to identify locations where anomalous conditions were present.
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Anticipated potential anomalies included timber pile, boulders, buried timber bulkhead or rock
seawall.
As indicated in Figure 6, numerous anomalies were interpreted along each of the GPR
transects. However, the interpreted anomalies appear to be intermittent, with concentrated
anomalies at varying depths and locations along each of the transects, but no apparent locations
or areas where anomalies were concentrated at the same depth and location along all four
transects. In addition, interpreted anomalies do not appear to be uniformly spaced as would be
expected if timber piling were present. The location of the horizontal boring is shown in
Figure 6, based on field measurements transferred onto the profiles using the scaled distances
included in the figure.
6.2 Electrical Resistivity Tomography (ERT)
The ERT geophysical method uses electrodes, which are driven into the ground to transmit
electrical current at specified locations and measure voltage received at other locations: The
measured apparent resistivity is representative of the electrical properties of the subsurface
materials, which can vary due to soil type, water content, and pore water chemistry.
Global Geophysics performed ERT surveys along transects two and four (Figures 2 and 7),
located along the top of the BNSF embankment and oriented approximately parallel to the rails.
The purpose of the ERT surveys was to identify locations along either transect where anomalous
conditions were present. Anticipated potential anomalies included timber pile, boulders, buried
timber bulkhead or rock seawall.
The locations of the ERT transects are indicated in Figure 2, and a report describing the methods
employed and interpreted data plots are presented in Appendix C.
As indicated in Figure 7, interpreted subsurface conditions along each of the two transects were
similar, with a zone of higher resistivity material near the top of the embankment, indicating
gravel or coarser rock which would typically exhibit higher resistivity as described in
Appendix C. The resistivity values grades to a zone of lower resistivity material between
approximately the base of the embankment and about 10 feet below the base of the embankment,
interpreted as beach sand with brine water. Beneath this zone, conditions then grade to a zone of
higher resistivity material extending to the lower limit of interpreted data extending to about 40
feet beneath the top of the embankment.
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The thickness of the higher resistivity material immediately below the ground surface is greater
along Transect 4, located along the outboard embankment edge. Otherwise the interpreted
conditions along the two transects are similar, with no concentrations of contrasting resistivity
materials within broader zones of similar resistivity. The location of the horizontal boring is
shown in Figure 7, based on field measurements transferred onto the profiles using the scaled
distances included in the figure.
7.0 GEOLOGY AND SUBSURFACE CONDITIONS
7.1 Regional Geology
The Puget Sound area was subjected to six or more major glacial events over the past 100,000
years, each depositing new sediment and partially eroding previous sediments. During the
intervening periods when glacial ice was not present, stream processes, wave action, weathering,
and landsliding eroded and reworked some of the glacially derived sediment, further
complicating the geologic setting.
During the most recent Vashon Stade of the Fraser Glaciation, the glacial ice is estimated to have
been about 3,000 feet thick in the project area (Thorson, 1989). The weight of the glacial ice
resulted in compaction and overconsolidation of the glacial and nonglacial sediments beneath the
ice. As the Vashon ice retreated around 13,500 years ago, sand and gravel outwash and mixtures
of sediments trapped in the ice were deposited. These recessional glacial deposits are overlain
by softer and looser alluvial and colluvial deposits. Development and land use continues to
modify the landscape in the Puget Sound.
7.2 Geologic Setting
Lund's Gulch Creek flows through Lund's Gulch and Meadowdale Beach Park to Puget Sound.
Lund's Gulch is a deeply incised valley in its upper reaches with a broader valley bottom in the
lower approximately 1/2-mile, but also with steep side slopes. At its western terminus, Lund's
Gulch Creek outlets through a concrete box culvert under the BNSF tracks across a sand and
gravel delta to Puget Sound. The creek generally flows in a northerly direction through the delta
as influenced by northward littoral drift, but periodically avulses and cuts a more direct westward
channel through the delta to reach Puget Sound before migrating northward again.
Lund's Gulch was carved through largely overconsolidated glacial and nonglacial sediments by
glacial meltwater. After the Vashon ice retreated, the land was uncovered and the steep slopes
along the sides of the meltwater channel became destabilized and slid or slumped into the valley
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(Applied Geotechnology Inc., 1986). Several of these glacial meltwater channels and slump
benches can be seen with terrain or light detection and ranging imaging between Edmonds and
Everett (Shannon & Wilson, 2015). These meltwater channels once carried a larger sediment
load than they do today and stream processes were operating at a much larger scale than they are
today. More recent landsliding has been documented in and around the project site. Several
stream and culvert clogging events occurred during the winters of 1996/97 and 2007/08
according to Doug Dailer (Pers. Comm., 2014). More recent landslides and slumps were
identified along the steep sides of the valley walls in the upper reaches of the ravine, contributing
sediment to Lund's Gulch Creek (Shannon & Wilson, 2015).
7.3 Geologic Units and Generalized Subsurface Conditions
Our interpretation of the subsurface conditions is based on geologic mapping by Minard (1983),
previous studies by others, and information obtained from our subsurface explorations. The
following sections describe the geologic units and generalized subsurface conditions encountered
in the explorations and anticipated throughout the site. Refer to the exploration logs in
Appendix A for detailed soil descriptions.
7.3.1 Geologic Units
7.3.1.1 Fill (Hf)
Fill represents imported soil and other materials or otherwise modified land.
Borings MB-3, MB-4, MB-7, HB-1, and HB-2 encountered fill in the upper approximately 5 to
12 feet. Fill at MB-3 and MB-4 consists of loose to medium dense, silty sand with gravel to
poorly graded sand with silt. This fill is similar to the native material, but less dense and likely
associated with road and shoulder fill. Fill observed in MB-7 consists of loose to medium dense
silt; silty sand; and sand with gravel, organics, wood, and glass refuse in the upper 4.5 feet.
Borings HB-1 and HB-2 encountered gravel to silty gravel with sand and cobbles in fill to about
6 feet deep. In some areas, fill may be indistinguishable from alluvium and colluvium. Test pits
TP-1, TP-2, TP-3, and TP-RE-1 encountered construction debris within soil fill to their full
depths, which ranged from about 4 to 10 feet. Test pit TP-RE-1 encountered fill in the upper
foot. The fill material is loose to medium dense silty sand with gravel, similar to the native
material encountered in borings MB-6, MB-7, and MB-8.
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7.3.1.2 Alluvium/Colluvium (Ha/Hc)
Alluvium and Colluvium is composed of sand and gravel with silt and clay
pockets. These units are typically designated together and reflect a complex depositional
environment in which sediments deposited by landslides of the valley walls (colluvium) were
intermixed with alluvium and reworked by streams in the valley bottom. Explorations HB-1
and HB-2 encountered Ha that consists of silty sand with trace gravel and clay clasts to the
bottom of the boreholes, 6 and 10 feet deep, respectively. Iron -oxide staining was encountered
1 foot from the bottom of each of these borings, indicating a fluctuating water level.
Explorations MB-6, MB-7, and MB-8 encountered two layers of Ha/Hc. The
upper layer consists of loose silt and sandy silt to loose, silty sand, sometimes interbedded or
with pockets of gravel. The lower layer consists of medium dense to very dense sand and
gravel layers in MB-6 and MB-7. The lower layer generally coarsened with depth in borings
MB-6 and MB-7. In MB-8, the lower layer consists stiff, lean clay with sand, little gravel, and
diamict texture. MB-8 encountered a possible slump block from the valley wall at about 15 feet
that is similar to the Whidbey Formation found in the valley walls. This layer is designated as
colluvium and Whidbey Formation as it is difficult to determine if the layer is a displaced block
or undisturbed. Test Pit TP-RE-1 encountered colluvium between 1 and 6 feet below ground
surface (bgs). The upper layer (1 to 3 feet bgs) consisted of silty sand with gravel and the lower
(3 to 6 feet) consisted of poorly graded sand. Borings encountered various amounts of wood
and organics throughout the Ha/Hc layers. The presence of coarse gravel or cobbles in MB-6
and MB-7 may have caused the blow counts to be artificially high.
7.3.1.3 Whidbey Formation (Qpnf and Qpnl)
The Whidbey Formation represents sediment deposited on the land surface
between glacial periods. These sediments were overridden by at least glacial advances and
consolidated to a very dense or hard state. The Qpnf component of the Whidbey Formation
represents sediments deposited in a fluvial environment and generally consists of very dense,
fine silty sand with a few silt interbeds. Qpnf also contains trace gravel, silt and sand seams, and
organics and fines are nonplastic to low plasticity. The Qpnl component of the Whidbey
Formation represents sediments deposited in a lake environment. Qpnl consists of hard silt to
sandy silt, with sand laminations. Fines in Qpnl have low plasticity or are nonplastic.
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7.3.2 Subsurface Conditions
7.3.2.1 Whidbey Formation Density
Borings MB-1 through MB-5 encountered Whidbey Formation Qpnf and Qpnl.
Sediments in the upper 20 feet in borings MB-3 through MB-5 were consistent with grain size
and appearance of Qpnf and Qpnl sediments observed elsewhere, but had lower blow counts,
registering as medium dense to dense instead of very dense. Stress relief within the valley walls
as the ice retreated, as coastal bluff and Lunds Gulch formed, or more recent weathering may
account for observed lower blow counts. Borings MB-6 and MB-7 encountered very dense Qpnf
and Qpnl below 50 and 77 feet, respectively.
Figure 4 presents a generalized subsurface profile A -A' near the proposed bridge
abutments, as shown in Figure 2.
7.3.2.2 Railroad Embankment Fill
The railroad embankment is composed of approximately 7 to 10 feet of fill. The
embankment fill observed during drilling of the horizontal boring consisted of sand and gravel,
as summarized in Figure 5. We observed slightly rough to rough drill action, with rig chatter and
slowed drill advance rate, interpreted to represent the presence of coarse gravel or cobbles. We
observed no wood fibers or freshly fractured rock chips in the drill cuttings, or drill action (e.g.,
drill advance rate becoming appreciably slower or stopping, operator applying obvious drill stem
thrust, etc.) that would indicate objects such as timber pile or boulders were encountered during
drilling. Additional information for the horizontal embankment boring is included in
Appendix A.
The railway embankment along the west park boundary was originally
constructed as a single-track alignment around 1891 by the Great Northern Railway (a
predecessor of BNSF), and the embankment was expanded to accommodate a second track
starting in 1907 (Intlekofer, 1989). Additional historical documents provided by the Great
Northern Railway Historical Society indicate the second main line through the project area had
been completed by June of 1907, and is referred to as a "slope wall," whereas segments north
and south of the project area were constructed as "sea wall," A historical cross section depicting
seawall construction includes large diameter "face rock" along the outboard edge of the second
main line for wave protection, and a timber bulkhead along the outboard edge of the original
single-track embankment (Intlekofer, 1989), presumably for the same purpose, and presumably
buried in -place.
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We have found no record in historical documents of the original embankment
composition, or of a trestle at the site, although trestles were commonly constructed for stream
crossings during original railroad construction. There are several references to timber culvert at
the site, and later references to concrete culvert replacement. We were provided a drawing that
corresponds well with the location and physical dimensions of the existing concrete culvert.
Based on our review of historical documents available to us, the railroad embankment does not
appear to contain buried seawall structure (boulder -sized rock), or timber trestle. Information
about the historical construction of the embankment is included in Appendix D.
7.3.2.3 Buried Manmade Debris
The purpose of test pits TP-1, TP-2, TP-3, and TP-B was to evaluate the presence
or absence, and nature of anomalies interpreted from the geophysical survey described in
Section 6.0. Anticipated potential anomalies included concrete slabs, walls, or other manmade
structures, as well as construction debris within the soil fill. The project team used the data
presented in Figure 3 to select test pit locations. We encountered construction debris in TP-1,
TP-2, TP-3, and TP-B. We terminated TP-3 excavation at 6.5 feet after encountering concrete
debris too large for the excavator to remove. The general stratigraphy of test pits TP-1, TP-2,
TP-3, and TP-B consisted of 1 to 2 feet of silty sand with gravel, with little to no construction
debris, overlying similar soil with increasing concentration of concrete fragments (with and
without rebar), wood construction debris, and metal fragments. The concentration of
encountered debris generally increased with depth. Test pits TP-1, TP-2, and TP-B encountered
horizontal concrete slabs at depths of approximately 4, 5, and 10 feet, respectively. The depth of
the concrete slabs generally increased to the west. We did not encounter vertical concrete walls
in any of the test pits.
7.4 Groundwater
Groundwater was encountered at all explorations on the valley floor, including HB-1, HB-2,
MB-6, MB-7, MB-8, TP-1, and TP-2. Borings HB-1 and HB-2 encountered shallow
groundwater at about 0.5 foot and at the ground surface, respectively, while advancing these
borings. Well readings taken three days after completing HB-1 and HB-2 indicated slightly
lower water levels at 5.5 feet and 3 feet, elevations 33.5 and 27 feet, respectively. Iron -oxide
staining in these borings indicates that groundwater levels fluctuate and may vary seasonally
with precipitation.
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Borings MB-6 and MB-7 encountered groundwater at 6 and 2 feet, at elevations 7 and 13 feet,
respectively. Shannon & Wilson staff observed seepage onto the trail near MB-7, indicating
shallow groundwater depths at this location. Groundwater levels at MB-6 and MB-7 may be
influenced by tidal fluctuations. Boring MB-8 encountered groundwater at 5 feet, at elevation
19 feet, and is likely influenced by stream water levels.
Test pits TP-2 and TP-3 encountered groundwater at 5 feet, at elevations 13 and, respectively.
Test pit TP-RE-1 encountered groundwater at 3.0 feet, elevation 19. Test pit TP-B encountered
groundwater at 6.2 feet, elevation 10.8 feet. No groundwater was encountered in TP-1.
We anticipate groundwater levels fluctuate seasonally, with higher levels during the wet winter
months anticipated to be at or near the current ground surface.
8.0 ENGINEERING CONCLUSIONS AND RECOMMENDATIONS
8.1 Design Standards
For design of the proposed railroad bridge, including temporary and permanent features, we have
adhered to the 2016 America Railway Engineering and Maintenance of Way Association
(AREMA) manual guidelines (AREMA, 2016). The AREMA manual is a design guideline and
not a rigid design standard, and refers to other standards as appropriate for specific design
elements. For seismic site characterization and site response, AREMA refers to the American
Society of Civil Engineers (ASCE) Minimum Design Loads for Buildings and Other Structures,
ASCE Standard ASCE/SEI 7-10 (ASCE, 2013).
For design of the proposed restroom enclosure structure, we have adhered to the Snohomish
County Department of Planning and Development Services (SCDPDS) Building Construction
Codes, which reference 2015 International Building Code design standards (International Code
Council, 2014). For design of the proposed pedestrian bridge, we have referenced the
International Building Code 2015 for seismic design requirements and SCDPDS Rule 5660
concerning design requirements for small -diameter (defined as less than 8 inches in diameter)
pipe piles, referred to as pin piles (SCDPDS, 2006).
8.2 Seismic Design
8.2.1 Site Class
The seismic site class was evaluated in general accordance with the procedure in ASCE
7-10, which allows the use of estimated shear wave velocities correlated from Standard
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Penetration Test (SPT) N-values to calculate the average shear wave velocity for the upper
100 feet of the subsurface materials. This site class is applicable for all proposed structures, as
both AREMA Section C-1.4.4.1.1 and International Building Code (IBC) (2015) reference
methods provided in ASCE 7-10 for this purpose. Our evaluation, based on the measured SPT
values from borings MB-6, MB-7, and MB-8 indicates that the project site is classified as Site
Class E. Site Class E corresponds to a loose soil profile with an average shear wave velocity less
than 600 feet per second or an average SPT N-value less than 15 blows per foot in the upper
100 feet of soil.
8.2.2 Railroad Bridge Seismic Design Parameters
The 2016 AREMA Manual for Railway Engineering (Chapter 9) utilizes a three -level
ground motion and performance -criteria limit state for the seismic design of railway bridges.
Return periods for each limit state can be calculated based on risk factors that consider
immediate safety, immediate value, and replacement value. The return period for each limit state
can then be used to calculate a corresponding base acceleration coefficient.
If the parameters used to determine risk factors are unknown, average return periods may
be used in conjunction with maps developed by the U.S. Geological Survey (USGS) to determine
base acceleration coefficients for each limit state. Preliminary USGS 2008 maps corresponding
to average return periods of 100, 475, and 2,475 years for the serviceability, ultimate, and
survivability limit states, respectively, are presented in the AREMA Manual as Figures 9-1-1
through 9-1-3. However, AREMA Chapter 9, Section 1.3.2.3, states that the provided ground
motion parameters maps are for illustration purposes and more accurate ground motions
parameters may be determined based on web -based interactive USGS tools. This section also
states that other sources or site -specific procedures may be used to define the ground motion
parameters as long as they are based on accepted methods. We recommend the current ground
motion parameter maps published by the USGS U.S. Seismic Design Maps (USGS, 2017) be
used for design. For railroad bridge design, we recommend applying the seismic design ground
motion parameters presented in Table 1.
8.2.3 Pedestrian Bridge Seismic Design Parameters
The IBC seismic design parameters are based on a maximum considered earthquake
(MCER), which corresponds to ground motions with a 1 percent probability of structural
collapse in 50 years. The NICER is the ground motion with a 2 percent probability of
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exceedance in 50 years (i.e., a 2,475-year return period) that has been adjusted for risk and
directionality in accordance with ASCE 7-10.
Seismic design using the IBC is based on short -period and 1 second -period spectral
response acceleration (SRA) values. To account for site soil amplification effects, we scale the
mapped SRA values from the USGS PSHA (Site Class B) by site coefficients corresponding to
Site Class E. For pedestrian bridge design, we recommend applying the seismic design ground
motion parameters presented in Table 1.
8.2.4 Liquefaction Potential
8.2.4.1 Railroad Bridge Liquefaction Potential
We evaluated liquefaction potential for borings MB-6 and MB-7 for the three
design ground motions specified in AREMA. Based on the SPT data, soil description, and
laboratory data for those borings, it appears both locations are susceptible to liquefaction under
all seismic cases. Boring MB-6 is susceptible to liquefaction in limited intervals at depths of
approximately 10 and 45 feet.
Boring MB-7 is susceptible to liquefaction between 35 and 40 feet during the
475- and 2,475-year return period events. We have applied these liquefied soil zones in related
analyses such as driven pile axial capacity and recommended LPile parameters.
8.2.4.2 Pedestrian Bridge Liquefaction Potential
We evaluated liquefaction potential for boring MB-8 using half the peak ground
acceleration corresponding to an earthquake having 2 percent probability of exceedance in
50 years, as specified in IBC 2015. Based on SPT data, laboratory results and observed soil
conditions, boring MB-8 is susceptible to liquefaction to a depth of 7 feet. We anticipate
liquefiable soils are present at both bridge abutments, and extend laterally in all directions from
the abutments. If liquefaction occurs, we anticipate both abutments may be affected
simultaneously, and that the liquefied ground will undergo lateral spreading toward the stream
channel. Due to anticipated bridge damage if liquefaction occurs to that depth, we recommend
removal of the upper 7 feet of soil beneath the pedestrian bridge abutments, and extending 15
feet upslope of the abutments, and replacing it with structural fill. Areas of soil removal and
replacement with structural fill should extend at least eight feet laterally beyond the edges of the
abutments and approach fills. Properly constructed structural fill will not be susceptible to
liquefaction and liquefaction -induced settlement.
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8.3 Railroad Bridge Design
Preliminary design drawings indicate the proposed railroad bridge spans will be supported on
precast concrete and steel pile caps and abutments, which will bear on driven pile foundations.
We understand the construction sequence calls for installing piles through the existing
embankment, then excavating to place pile caps and abutment blocks, deck spans, and track
elements before excavating the embankment beneath the deck and installing steel cross members
at each bent. Construction stages will be coordinated within single track closure windows, after
which both tracks will be put back into service such that the tracks will have to be service -ready
after each construction stage. We understand the bridge will be constructed one track at a time,
with the first bridge being completed and put into service before the second bridge is
constructed. As such, it will be necessary to install shoring between the two tracks to support
embankment soil and track surcharge loads during excavation beneath the deck to connect steel
cross members, and throughout much of construction of the second bridge.
The analyses and recommendations in this section address specific details of the railroad bridge
design and construction sequence described above, presented by the project design team in the
30 percent design submittal, and discussed during subsequent project meetings preceding this
report. If the railroad bridge design or construction sequence changes, or if performance
requirements differ from those described in the following sections, our analyses and
recommendations would need to be revised.
8.3.1 Driven Pile Foundations
We have estimated axial capacity for driven steel, HP 14X89 piles, based on the
subsurface conditions observed in borings M13-6 and M13-7, as presented in Figures 8 and 9,
respectively. Note that the axial capacities are presented relative to the approximate bottom of
the elevation, and should be adjusted for interior bents.
Efficient pile driving can be defined as driving the pile to the desired ultimate capacity
(twice the design load) at a reasonable blow count (less than 140 blows per foot) and with
driving stresses not exceeding 80 percent of the yield strength of the pile (in accordance with
AREMA). Wave Equation Analyses for Pile driving (WEAP) should be performed using data
for the actual hammer/pile combination to be used to install the production piles. WEAP
analyses allow evaluation of driving stresses so that an appropriate pile -driving hammer size can
be selected to obtain the desired pile capacity with reasonable blow counts and without damaging
the piles. We evaluated driven steel, HP 14X89 piles, to accommodate a nominal capacity of
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250 tons (500 kips), as requested by the design team. We evaluated for both plugged and non -
plugged conditions.
WEAP were performed for steel with a yield strength of 50 kips per square inch (ksi)
HP 14X89 pile driven with a Berminghammer B-5505 diesel hammer. A Berminghammer
B-5505 has a manufacturer -rated energy of about 105,900 foot-pounds and a ram weight of
about 9.2 kips. Based on the uncertainty in driving conditions, plugged or unplugged, we
selected a hammer that would achieve capacity for the limiting driving condition. For driving
with an unplugged condition, a greater embedment depth is necessary to achieve capacity. The
analyses were performed using the computer program GRLWEAP (Version 2010), which was
developed by Goble Rausche Likins and Associates (GRL, 2010). The hammer size was
selected based on our past experience. Analyses were performed for the following conditions:
■ For driving HP 14X89 under plugged conditions, an embedment of 120 feet and total
pile length of 130 feet.
■ For driving HP 14X89 under plugged conditions, an embedment of 130 feet and total
pile length of 140 feet.
■ We used standard GRLWEAP-recommended values for damping, quake, and shaft
damping for the soil types encountered at the project site.
■ We used standard GRLWEAP-recommended values for cushion and helmet values
for the hammer.
■ To achieve an ultimate capacity of about 250 tons (500 kips), a Berminghammer
B-5505, or equivalent, would be acceptable for driving the 50 ksi HP 14X89 steel
H-Piles.
8.3.2 Lateral Earth Pressures
Temporary shoring will be necessary to retain embankment soil during sequential bridge
construction. Bridge abutment structures will be subjected to lateral earth pressure from
embankment soil. The following sections discuss lateral earth pressure analyses for the railroad
bridge.
8.3.2.1 Railroad Bridge Temporary Shoring
Steel sheet pile or H-pile with steel sheet lagging temporary shoring will be
installed between the tracks to support the embankment soils and track during excavation to
install bridge spans and pile bent reinforcements. Based on the soil conditions observed during
the horizontal boring, HB-1, we evaluated lateral earth pressure that may be anticipated to act on
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temporary shoring structures. Recommended lateral earth pressures for a cantilevered sheet pile
wall under drained conditions are presented in Figure 10.
Note that we did not provide recommended lateral earth pressures for single or
multiple tieback wall configurations because the shoring will be inaccessible prior to excavating
beneath the adjacent track. If the design and surcharge loads cannot be feasibly supported by a
cantilevered wall, additional analyses will be required. Lateral pressures due to surcharges,
including Cooper E80 train loading should be added to the recommended lateral earth pressures
when appropriate. Various recommended surcharge loads are presented in Figure 11. To
estimate surcharge loading for temporary shoring, as presented in Figure 11, we recommend
using an active earth pressure coefficient (Ka) of 0.36.
8.3.2.2 Temporary Shoring Wall Anticipated Movements
The lateral earth pressures in Figure 10 assume active soil conditions. For active
conditions, lateral wall movements could range from 0.10 to 0.15 percent of the excavation
depth. In general, settlements of the same order -of -magnitude could occur behind the wall,
extending a distance equal to approximately half the height of the excavation, then decreasing
linearly to zero at a distance of approximately 1.5 to 2 times the excavation height.
Lateral earth pressures acting on retaining walls depend on many factors,
including groundwater conditions, backslope, surcharges, the type of backfill soil and/or adjacent
native soils, drainage provisions, and wall flexibility. For walls that are not allowed to move
0.001 times the wall height (rigid condition), at -rest lateral earth pressures should be used.
The above -mentioned deflections and settlements are estimates only and are, in
part, affected by the method and care used during installation. The actual performance of the
wall should be monitored during construction as discussed later in this report.
8.3.3 Bridge Abutments
Bridge abutment structures will be subjected to lateral earth pressures along their exterior
face (opposite the bridge spans). We anticipate the abutment structures will be constrained
laterally in the track -parallel direction, restricting movement such that they may not develop
active soil conditions. We recommend designing for at -rest earth pressure conditions. We
recommend designing for an equivalent fluid pressure of 55H, expressed in pounds per square
foot (psf), where H represents the distance from the finished ground surface to the point of
interest on the abutment face. We recommend modeling the earth pressure in a triangular
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distribution, increasing with depth. Lateral pressures due to surcharges, including Cooper E80
train loading should be added to the recommended lateral earth pressures when appropriate.
Various recommended surcharge loads are presented in Figure 11. For the seismic case, we
recommend adding a seismic increment of 12H (psf) in a uniform rectangular distribution. To
estimate surcharge loads for the railroad bridge abutments using Figure 11, we recommend
applying an at -rest earth pressure coefficient (Ko) of 0.42. We recommend ignoring friction
along the base of the abutment structure because it will be pile -supported, and embankment soil
may settle relative to the abutment. We anticipate there will be no backfill along the interior face
of the abutment structure such that passive earth pressure will not provide lateral resistance to the
active earth pressure.
8.3.4 Permanent Slopes
We anticipate the completed bridge will include newly constructed permanent slopes
beneath the bridge, downslope of the abutments, leading to the completed estuary restoration
excavation. Based on the observed soil conditions in horizontal boring HB-1, we recommend
permanent slopes be 1.5H:1V or flatter. Permanent slopes formed in existing railroad
embankment materials are likely to expose granular soils that are susceptible to erosion. We
recommend permanent slope designs include permanent erosion control measures such as
reestablishing vegetative cover, or placement of coarse gravel, quarry spalls, or other erosion
resistant stone.
8.3.5 Retaining Wall at Pedestrian Path
Based on the 30 percent submittal, and on subsequent conversations, we understand the
preferred alternative is to construct a concrete block wall (each primary block is 59 inches long
by 29.5 inches tall and 29.5 inches deep) as a permanent structure at the base of the slope
between the pedestrian path and south abutment. The block wall will retain about 5 feet of
embankment soil having a backslope of 1.5H:IV.
Based on the soil conditions observed in boring MB-6 (approximate elevation 13 feet),
soil conditions at the base of the wall may consist of soft silt and organic silt to a depth of about
three feet, underlain by loose, silty sand to a depth of about 5 feet, underlain by very loose, clean
sand with gravel to a depth of about 9.5 feet. The base of the block wall is shown at
approximately elevation 8 feet. Based on the elevation difference between the ground surface at
MB-6 (approximate elevation 13 feet) and the proposed base of the block wall (approximate
elevation 8 feet), we anticipate the block wall subgrade soils will be loose to very loose, silty
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sand or clean sand with gravel. We recommend overexcavating a minimum of 24 inches below
the finished base of block elevation, compacting the native soil to a firm and unyielding
condition, then backfilling and compacting free -draining, coarse, angular gravel or quarry spalls
to within 6 inches of the finished base of block elevation. We recommend placing and
compacting 6 inches of free -draining, leveling rock to form a firm, uniform surface on which to
place the base blocks. Leveling rock fill material should consist of clean, well -graded, sand and
gravel soils of which not more than 5 percent fines by dry weight passes the No. 200 mesh sieve,
based on wet -sieving the fraction passing the 3/4-inch mesh sieve, such as Washington State
Department of Transportation (WSDOT) Standard Specification 9-03.12(B) Gravel Backfill for
Walls. The fines should be nonplastic. We recommend this material be used as backfill behind
the completed block wall. For wall design, we recommend assuming this material has an angle
of internal friction (cp) equal to 32 degrees, and total unit weight (y) equal to 125 pounds per
cubic foot.
8.4 Pedestrian Bridge
The proposed pedestrian bridge is located approximately midway between the proposed railroad
bridge and the existing pedestrian bridge near the Ranger's residence. Based on the 30 percent
design drawings, and subsequent conversations with the bridge designers, we understand the
structure will be a single 40-foot span bearing on pile -supported abutments. Abutment approach
fills will be retained by cast -in -place concrete wingwalls bearing on spread footings. The south
abutment approach will consist of an elevated boardwalk bearing on Diamond Pier® foundation
elements.
8.4.1 Bridge Abutment Foundations
We understand the proposed bridge will be supported on concrete abutments bearing on
driven pile foundations. We have provided estimated axial capacity for 2-, 4- and 6-inch-
diameter, driven steel pipe piles based on the subsurface conditions observed in boring MB-8
and assuming liquefaction mitigation is completed as discussed in Section 8.2.4.2 of this report,
as presented in Figures 12, 13, and 14, respectively. Note that the axial capacities are presented
relative to the existing ground surface. Typically, small -diameter pin piles are driven to refusal
(defined as 1 inch or less of penetration after 60 seconds of driving using a 90-pound
jackhammer for a 2-inch-diameter pile) in dense to very dense soils. At this location, we did not
encounter dense to very dense soils, so we do not anticipate pile refusal. Consequently, we
anticipate the pin piles at this location will not achieve the maximum capacities stated in
SCDPDS Rule 5660. We understand the design calls for battered piles. We recommend
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estimating the vertical and horizontal pile capacity components, not accounting for bending
resistance, by resolving the pile batter angle into its geometric horizontal and vertical
components and multiplying by the estimated vertical pile capacity based on pile tip embedment
depth. To carry tensile or lateral loads, pipe pile splices would need to be field welded.
Based on SCDPDS Rule 5660, 2-inch-diameter pin piles shall be no more than 30 feet
long and shall be of extra strong steel as defined in the American Institute of Steel Construction
(AISC) Steel Construction Manual (AISC, 2011). Extra strong is a class of steel pipe which has
nominal inside and outside diameters of 1.94 and 2.38 inches, respectively, with steel materials
in accordance with ASTM Designation A53 Gr. B. For the 4- and 6-inch-diameter piles,
SCDPDS Rule 5660 specifies at least 3 percent and up to five piles maximum be subjected to
static axial compressive load testing in general accordance with ASTM D1143-81, Quick Load
Test Method.
We recommend the base of the pedestrian bridge abutments be at least 24 inches below
surrounding grade. Based on soil conditions observed in boring MB-8, we anticipate the
excavation will expose very loose silty sand, and could potentially be at or below the
groundwater table if completed during the wet winter months. We anticipate the exposed soils
will be susceptible to degradation under construction activities, and recommend overexcavation
and placement of quarry spalls or other suitable material to provide a firm working surface.
8.4.2 Lateral Earth Pressure
We understand the abutment structures will be 5 feet tall from their base to the proposed
bridge deck elevation, and that each abutment will support an approach fill. Bridge abutment
structures will be subjected to lateral earth pressures imparted by the approach fills. Lateral earth
pressures will be dependent on whether liquefaction mitigation is completed, as described in the
following sections.
8.4.2.1 Existing Condition — Static
We anticipate the abutment structures will deflect laterally such that they develop
active soil conditions. We recommend designing for active earth pressure conditions. We
recommend designing for an equivalent fluid pressure of 34H (psf) for static conditions, where H
represents the distance from the finished ground surface to the point of interest on the abutment
face. We recommend modeling the earth pressure in a triangular distribution, increasing with
depth. This recommended value assumes the abutment wall backfill and approach fill are
composed of structural fill as described in Section 8.2.3 of this report. Lateral pressures due to
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surcharges, including vehicle loading should be added to the recommended lateral earth
pressures when appropriate. Various recommended surcharge loads are presented in Figure 11.
To estimate surcharge loads for the pedestrian bridge abutments using Figure 11, we recommend
applying an active earth pressure coefficient (Ka) of 0.27. We recommend ignoring friction
along the base of the abutment structure because it will be pile -supported, and the underlying soil
may settle relative to the abutment. We anticipate there will be no backfill along the stream -side
face of the abutment structure such that passive earth pressure will not provide lateral resistance
to the active earth pressure.
8.4.2.2 Existing Condition — Seismic
For the seismic case, with liquefaction and lateral spreading occurring at both
abutments, there is potential that both abutments would be subjected to passive earth pressure
acting in opposite directions as the ground surrounding and underlying each abutment deforms
toward the stream channel. For this case, we recommend applying an equivalent fluid pressure
(ultimate passive) of 400H (psf), at each abutment, where H represents the distance from the
finished ground surface to the point of interest on the abutment face, and modeling the earth
pressure in a triangular distribution starting at the ground surface, increasing with depth to the
base of the abutment footing. This recommended ultimate passive earth pressure value is
unfactored.
8.4.2.1 Mitigated Condition — Static
We anticipate the abutment structures will deflect laterally such that they develop
active soil conditions. We recommend designing for active earth pressure conditions. We
recommend designing for an equivalent fluid pressure of 3 1 H (psf) for static conditions, where H
represents the distance from the finished ground surface to the point of interest on the abutment
face. We recommend modeling the earth pressure in a triangular distribution, increasing with
depth. These recommended values assume excavation and replacement with structural fill as
described in Section 8.2.3 of this report. Lateral pressures due to surcharges, including vehicle
loading should be added to the recommended lateral earth pressures when appropriate. Various
recommended surcharge loads are presented in Figure 11. To estimate surcharge loads for the
pedestrian bridge abutments using Figure 11, we recommend applying an active earth pressure
coefficient (Ka) of 0.23. We recommend ignoring friction along the base of the abutment
structure because it will be pile -supported, and the underlying soil may settle relative to the
abutment. We anticipate there will be no backfill along the stream -side face of the abutment
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structure such that passive earth pressure will not provide lateral resistance to the active earth
pressure.
8.4.2.2 Mitigated Condition — Seismic
For the seismic case, when liquefaction mitigation is completed, we anticipate
active earth pressure acting at one bridge abutment may be resisted by passive earth pressure
acting at the opposite bridge abutment, and in the opposite direction, provided the structure
adequately transfers the load between abutments. For this case, we recommend applying the
static earth pressure described in Section 8.4.2.1, and adding a seismic increment of 12H (psf) in
a uniform, rectangular distribution. For the opposite abutment, we recommend applying a
passive earth pressure of 250H (psf), where H represents the distance from the finished ground
surface to the point of interest on the abutment face, and modeling the earth pressure in a
triangular distribution starting at the ground surface, increasing with depth to the base of the
abutment footing. This recommended passive earth pressure value includes a factor of safety
(FS) of 2.0.
8.4.3 Approach Fill Wingwalls
We understand the approach fills will be retained by concrete wingwalls along both sides,
extending from the bridge abutments. We recommend the base of the wall footings be at least
24 inches below surrounding grade. Provided the exposed subgrade is prepared in accordance
with the recommendations in Sections 8.8 and 8.9 of this report, we recommend designing for an
allowable bearing pressure of 2,000 psf. Anticipated total settlements may be up to 1.0 inch, and
differential settlement along continuous footings is estimated to be approximately half the total
settlement. We recommend the wingwalls be backfilled using structural fill, and designed using
the same recommended earth pressures.
The above allowable bearing capacities include a FS of 2.0. Bearing pressures may be
increased by up to one-third for seismic and wind loads. The estimated settlements are expected
to occur as structural loads are applied. Minimum footing widths should be 18 inches for
continuous spread footings.
Lateral loads may be resisted by passive earth pressure acting against the footing and
friction against the bottom of the footing. In our opinion, passive earth pressures developed from
compacted granular fill could be estimated using an equivalent fluid pressure of 300H (psf),
where H represents the distance from the finished ground surface to the point of interest on the
wingwall. We recommend ignoring passive resistance in the uppermost 24 inches. The
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equivalent fluid pressure includes a FS of 1.5 and assumes that the adjacent grade is level, the
footings extend at least 24 inches below the lowest adjacent grade, are properly drained, and that
the backfill around the structure is compacted in accordance with the recommendations for
structural fill outlined herein. We recommend that a coefficient of friction of 0.35 be used
between cast -in -place concrete and medium dense fill. This value includes a FS of 1.5.
We anticipate the abutment wingwalls will deflect laterally such that they develop active
soil conditions. We recommend designing for active earth pressure conditions. We recommend
designing for an equivalent fluid pressure of 34H (psf) for static conditions, where H represents
the distance from the finished ground surface to the point of interest on the wingwall. We
recommend modeling the earth pressure in a triangular distribution, increasing with depth. This
recommended value assumes the wingwall backfill and approach fill are composed of structural
fill as described in Section 8.2.3 of this report. Lateral pressures due to surcharges, including
vehicle loading should be added to the recommended lateral earth pressures when appropriate.
Various recommended surcharge loads are presented in Figure 11. To estimate surcharge loads
for the pedestrian bridge abutments using Figure 11, we recommend applying an active earth
pressure coefficient (Ka) of 0.27.
The approach fills and wingwalls are susceptible to damage in the event that liquefaction
mitigation is not completed. Additional settlement and lateral deformation may be expected if
liquefaction occurs.
8.4.4 Diamond Pier ® Boardwalk Foundations
We understand the proposed boardwalk structure south of the pedestrian bridge will be
supported on Diamond Pier ® foundation elements. Based on the soil conditions observed in the
test pits within the grassy playfield, and in boring MB-8 near the pedestrian bridge, we anticipate
the boardwalk foundations will bear in silty sand or silty sand with gravel. We recommend
applying the bearing load capacity values listed in the Sands/Gravels portion of Table 1 in the
Diamond Pier ® Installation Manual (Pin Foundations, Inc., 2018) for the specified model and
pin length.
8.5 Lateral Pile Analysis
Lateral loads may be resisted by the passive pressure against deep foundations. The computer
program LPILE (Reese and others, 2016) and other similar methods may be used to generate
load deflection (p-y) curves for lateral resistance analysis of driven piles to calculate the
magnitude of deflection, shear, and moment along the pile. Table 2 presents our recommended
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soil parameters for lateral resistance analysis using LPILE for static and seismic loading
conditions.
Group interaction should be considered when evaluating horizontal movement of piles with
center -to -center spacing less than 5D. When the p-y method is used, the lateral resistance "p"
should be factored by the appropriate p-multiplier set forth in the AASHTO LRFD Bridge
Design Specifications, 71h Edition, Article 10.7.2.4 — Horizontal Pile Foundation Movement, to
account for group interaction (American Association of State Highway and Transportation
Officials [AASHTO], 2016).
8.6 Restroom Enclosure Foundations
We understand the proposed restroom enclosure structure will be slab -on -grade with specific
elements being supported on spread footings. We evaluated bearing capacity and settlement for
the soil conditions encountered at test pit TP-RE-1.
8.6.1 Bearing Capacity
We recommend the base of spread footings be at least 24 inches below the surrounding
grade. Based on soils observed in test pit TP-RE-1, subgrade soil will be silty sand with gravel.
Provided the exposed subgrade is prepared in accordance with the recommendations in Sections
8.8 and 8.9 of this report, we recommend designing for an allowable bearing pressure of
3,000 psf. Anticipated total settlements may be up to 0.5 inch, and differential settlement
between adjacent column footings or along continuous footings are estimated to be
approximately half the total settlement.
The above allowable bearing capacities include a FS of 2.0. Bearing pressures may be
increased by up to one-third for seismic and wind loads. The estimated settlements are expected
to occur as structural loads are applied. Minimum footing widths should be 24 inches for
individual column footings and 18 inches for continuous spread footings.
For portions of the structure supported on shallow foundations, lateral loads may be
resisted by passive earth pressure acting against the footing and friction against the bottom of the
footing. In our opinion, passive earth pressures developed from compacted granular fill could be
estimated using an equivalent fluid pressure of 300H (psf), where H represents the distance from
the finished ground surface to the point of interest on the footing. We recommend ignoring
passive earth pressure resistance in the uppermost 24 inches. The equivalent fluid pressure
includes a FS of 1.5 and assumes that the footings extend at least 24 inches below the lowest
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adjacent grade, are properly drained, and that the backfill around the structure is compacted in
accordance with the recommendations for structural fill outlined herein. We recommend that a
coefficient of friction of 0.35 be used between cast -in -place concrete and medium dense fill.
This value includes a FS of 1.5.
8.6.2 Slab -on -Grade
Floor slabs for the proposed structure may be slab -on -grade bearing on densely
compacted structural fill. We recommend the area be prepared by removing all existing fill;
loose, soft, or disturbed soils; organics; and debris (if present) to expose the underlying native
soils. The exposed native soils should be evaluated by a geotechnical engineer or the engineer's
representative prior to backfill or concrete placement. All new fills under slab -on -grade floors
should consist of structural fill and be compacted to a dense, unyielding condition according to
the recommendations presented herein. For floor slabs prepared in accordance with these
recommendations, we recommend using a modulus of subgrade reaction, k, of 200 pounds per
cubic inch for design of the slab.
8.7 Access Road Stability Improvements
We performed slope stability analyses of the access road using the Morgenstern -Price limit -
equilibrium method, using the software SLOPE/W (Geo-Slope International Ltd, 2016). We
evaluated the subsurface conditions at each of the five borings along the access road (MB-1
through MB-5), and concluded that the conditions at boring MB-4 were representative of typical
conditions at each of the borings. We focused our analyses at the approximate location of boring
MB-4, between the existing soldier pile wall and mechanically stabilized earth wall, where we
observed guard rail displacement in the downslope direction.
We used the project topographic survey to create a section at the analysis location. Based on
observed subsurface conditions, we estimated 7 feet of road prism fill at boring MB-4. Based on
the topographic survey and observed field conditions, we modeled the access road as a cut/fill
prism having a wedge of fill beneath the downslope shoulder and extending approximately
75 feet downslope from the road. We completed a back -calculation, evaluated the existing
conditions under anticipated construction equipment surcharge loading, and evaluated driven soil
nail slope reinforcement under anticipated construction equipment surcharge loading as
described in the following sections.
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8.7.1 Back -Calculation
Because it is difficult to develop representative strength properties of the materials that
comprise the slope by laboratory testing, we estimated these properties based our experience
with road prism fill and glacial soils in the Puget Sound region, then used back -calculations to
refine the model.
Back -calculation is an iterative process in which the strength properties of a given soil
material are adjusted, within the limits of typical values for similar soils, to obtain an expected
FS. FS refers to the ratio of "resisting forces" to "driving forces." Landslides occur when the
driving forces on a block of soil exceed the available resistance; i.e., the FS drops to a value less
than 1. Once the slope geometry reaches a stable configuration (i.e. the FS increases to 1), the
slide stops moving. The unit weight for each material was estimated based on our experience
and laboratory testing of similar soils, and the friction angle and cohesion were adjusted.
Based on SPT N-values, observed soil conditions, experience with similar soils in this
area, and iterative back -calculation, we estimated the following soil strength parameters of the
roadway fill and the Whidbey formation:
Roadway Fill: � = 26% c = 200 psf
Whidbey Formation: � = 40°; c = 150 psf
We estimated groundwater conditions based on observed soil conditions in the borings,
seepage along the slope above the lower hairpin curve, and on experience with interbedded
stratigraphy such as was observed in the Whidbey formation in boring MB-4. We assumed three
perched groundwater tables in our stability model:
■ Groundwater Table 1 = 9 feet below access road
■ Groundwater Table 2 = 25 feet below access road
■ Groundwater Table 3 = 49 feet below access road
The resulting FS for existing conditions is 1.2. Because slope failures occur during the
wet winter months, we modeled an elevated water table within the roadway fill and upper
Whidbey formation, in which the water rose 4 to 5 feet below the access road surface, which
resulted in a FS of 1.0. In our opinion, this modeled condition provides a reasonable estimate of
existing and potential conditions on which to base further analyses.
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8.7.2 Anticipated Equipment Surcharge
Using the back -calculated strength properties, assumed dry -season groundwater levels,
and the existing slope geometry as a baseline condition, we then evaluated the stability of the
slope under anticipated equipment surcharge loading, and with proposed slope reinforcement
elements to evaluate the relative stability improvement from the proposed measures.
8.7.2.1 Dump Truck Surcharge
Based on the WSDOT Geotechnical Design Manual (GDM) (WSDOT, 2015),
conventional practice is to model construction equipment traffic as a uniformly distributed
surcharge of 250 psf, acting across the entire roadway width. Due to the anticipated volume of
dump truck and other equipment traffic, we modeled a uniformly distributed surcharge of
500 psf and another of 1,000 psf to account for dynamic loading. Under both conditions, the
resulting FS was 1.1.
8.7.2.2 Crawler Crane Surcharge
Based on anticipated construction equipment discussed during conference calls
with the project team, and on crawler crane specifications provided by the constructability
reviewer, we modeled a Hylab Model 218 HSL crawler crane with rated lift capacity of 110 tons.
The base crane chassis with crawler undercarriage side frames has a rated weight of 100,696
pounds. The crawler side frames are 20.5 feet long, and the pads are 3 feet wide. In its retracted
configuration, the crawler is 12 feet wide, and in its extended configuration the crawler is
17.2 feet wide, outside to outside of the track pads. Based on these machine specifications, we
modeled each of the crane crawler pads as a distributed load of 850 psf, acting over the pad
width of three feet, and acting at the extended configuration of 17.2 feet wide, outside to outside.
We evaluated the crane surcharge as though the machine was located close to the ditch and as
though it was located near the edge of the roadway. In both cases, the resulting FS was 1.1.
8.7.3 Proposed Access Road Stability Improvement
Based on the stability analysis results, and on the WSDOT GDM recommended
minimum FS of 1.25 for permanent slopes, we recommend considering access road stability
improvement measures to increase the FS under existing and construction surcharge conditions.
Based on the assumption that measures such as regrading to flatten the slope, or road fill
reconstruction would be too invasive, we focused on measures to reinforce the existing road fill.
We considered soldier pile walls and several in situ soil reinforcing measures such as drilled and
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grouted soil nails. Based primarily on their comparatively low impact to existing conditions, we
recommend considering spiralnails, which are directly -driven, steel soil nails manufactured by
Hilfiker Retaining Walls, in conjunction with slope face confinement structures such as their
spider hub, to improve access road stability.
We modeled the existing access road conditions with five rows of 30-foot-long
spiralnails, spaced 5 feet horizontally and vertically, driven at 15 degrees declination from
horizontal, with spider hub confinement structures. Under modeled slope conditions, the nails
would extend approximately 15 to 20 feet into the intact native soil. We assumed the spiralnails
would develop 1,000 psf (7 pounds per square inch) of shear resistance between the nail and
surrounding soil. We anticipate shear resistance will be greater in the intact native soil than in
the road prism fill, such that the selected value represents an average.
Stability analyses using this reinforcement indicate the FS increases from 1.2 for the
unreinforced condition to 1.9 for the reinforced condition, an increase of about 60 percent.
Under the dump truck and crawler crane surcharge loads described previously, the FS increases
from 1.1 for the unreinforced condition to 1.3 for the reinforced condition, an increase of about
18 percent, and sufficient to achieve the minimum recommended value of 1.25.
8.8 Site Preparation
We encountered loose or soft soil conditions at all proposed structure locations, including the
restroom enclosure, pedestrian bridge abutments, and retaining wall at the pedestrian path
beneath the proposed railroad bridge. Spread footings or other structure loads bearing on
existing soils would be susceptible to excessive settlement and potential bearing capacity failure.
The recommended allowable bearing capacities presented previously in this report are contingent
upon site preparation in accordance with the following recommendations.
Based on loose to very loose soil conditions encountered at all proposed structure locations, we
recommend removing 24 inches of existing soil, then preparing the subgrade in accordance with
the following:
■ Footing subgrade excavations should be cleaned of all fill, debris, and loose, soft,
wet, or disturbed soil prior to placing the reinforced concrete.
■ Exposed footing subgrade should be compacted to a dense and unyielding condition
using excavator mounted compaction equipment. Compaction should be observed by
a geotechnical engineer to confirm a dense and unyielding condition.
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If unanticipated loose, soft, or unsuitable soil is encountered below the footing level,
the subgrade should be overexcavated to a suitable bearing soil. The overexcavated
portion may be backfilled with a compacted granular structural fill, controlled density
fill (CDF), or lean concrete as appropriate to attain the design bearing capacity. The
structural fill should be compacted as recommended in Section 8.9 of this report.
CDF and lean concrete mixes must have sufficient design strength to support
foundation loads.
If construction takes place in wet weather, we recommend placing 2 to 3 inches of
lean concrete or at least 6 inches of compacted, well -graded, clean sand and gravel
immediately after excavation to serve as a working surface. The clean sand and
gravel should have less than 5 percent by dry weight passing the No. 200 sieve based
on the 3/4-inch minus fraction. If groundwater is encountered, it should be lowered to
at least 2 feet below the bottom of footing excavations. Footing excavations should
be kept free of water at all times.
■ As needed, temporary dewatering of accumulated stormwater should be performed
during construction to maintain dry working conditions. We anticipate that sump
pumps will be suitable for removing accumulated stormwater from the excavations.
All excavations for spread footing foundations should be observed by a geotechnical
engineer to evaluate the adequacy of the bearing stratum and to confirm that
subsurface conditions at and below the bearing elevation are suitable for the design
bearing values provided.
8.9 Compaction, Structural Fill Placement, and Use of On -site Soils
In load -bearing areas, such as beneath foundations, floor slabs, and pavements, the exposed soil
surface, after clearing and stripping and prior to any fill placement or foundation or pavement
construction, should be compacted using a heavy vibratory roller or backhoe-mounted hydraulic
plate compactor, or evaluated by an experienced geotechnical engineer. Where unsuitable soil
that is loose, soft, wet, or contains organic material is encountered during the compaction
process, it should be removed and replaced with densely compacted structural fill.
Native granular soil in dry conditions and granular on -site fill material without debris, wood, and
free of topsoil (abundant organic material) would be suitable for use as structural fill provided
the soil is within +/- 2 percent of its optimum moisture content for compaction. On -site fill soil
could be re -used as structural fill provided it is evaluated by a geotechnical engineer and used
following the recommendations in this section. The fines content of on -site soils may make them
difficult to compact during wet weather or in wet conditions. On -site soil could be used as fill in
dry weather and dry conditions, but may require thinner lifts and/or more effort to achieve
compaction requirements.
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Imported structural fill soil should consist of a well -graded mixture of sand and gravel; free of
organics, debris, and rubbish; and should contain no more than 15 percent fines (material passing
the No. 200 mesh sieve, based on the minus 3/4-inch fraction). The fines should be nonplastic,
and the moisture content of the soil should also be within +/- 2 percent of its optimum. All
structural fill should have a maximum particle size of 3 inches, such as WSDOT Standard
Specification 9-03.12(B) Gravel Backfill for Walls.
Structural fill should be placed in uniform lifts and compacted to a dense and unyielding
condition, to at least 95 percent of the Modified Proctor maximum dry density (ASTM
D 1557-70). The thickness of soil layers before compaction should not exceed 8 inches for heavy
equipment compactors or 4 inches for hand -operated mechanical compactors. In landscaped
areas where larger settlements are acceptable, the backfill should be compacted to at least
90 percent of the Modified Proctor maximum dry density.
During wet weather or in wet conditions where control of soil moisture is difficult,
structural fill material should consist of clean, granular soil, of which not more than 5 percent by
dry weight passes the No. 200 mesh sieve, based on wet -sieving the fraction passing the 3/4-inch
sieve. The fines should be nonplastic
9.0 CONSTRUCTION CONSIDERATIONS
9.1 Temporary Excavation Slopes
Consistent with conventional practice, temporary excavation slopes should be made the
responsibility of the Contractor, who is continually at the site and able to observe the nature and
conditions of the subsurface materials and groundwater and has responsibility for the methods,
sequence, and schedule of construction.
For planning purposes, we recommend that temporary, unsupported, open -cut slopes in existing
fill be no steeper than 1.5H:IV. This recommendation is applicable to slopes in areas where
groundwater and/or groundwater seepage is not present. Flatter slopes may be required based on
the actual conditions encountered, particularly where groundwater or seepage is encountered.
We recommend that all exposed slopes be protected with waterproof covering during periods of
wet weather to reduce sloughing and erosion.
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9.2 Driven Piles
9.2.1 General
The proposed construction sequence requires driven piles, both HP 14X89 foundation
piles and steel sheet piles, to be advanced through the existing embankment and into the
underlying soil. Once the bridges are completed, the embankment soil and approximately 3 to
6 feet of soil underlying the embankment and throughout the estuary restoration area will be
removed. Consequently, axial pile capacity and lateral pile analyses must be evaluated relative
to the proposed finished ground surface elevation.
9.2.2 Obstructions
Although we did not encounter boulder -size rock, timber piles, or other obstructions
during our subsurface explorations, we anticipate obstructions may be present within the existing
railroad embankment and underlying alluvium. Such obstructions will likely deflect piles and
cause alignment problems, and may stop pile advancement short of the design tip elevation. If
obstructions are encountered, and if pile alignment and/or penetration are negatively affected, it
may be necessary to pre -drill through and beyond the obstructions to facilitate driven pile
installation in accordance with the design.
9.3 Construction Impacts to Railroad Tracks
The railroad tracks and ties will potentially be affected by pile driving or drilling, by excavation
to install abutment and interior bent pile caps, and by shoring deflection during excavation to
complete the adjacent bridge. We anticipate these impacts can be mitigated through tamping and
other routine maintenance practices.
9.4 Embankment Excavation and Shoring Monitoring
We recommend that embankment excavation and shoring be observed by an experienced
geotechnical engineer. The purpose for this observation is to monitor conditions for indications
of excessive shoring deflection or other signs of adverse ground response during construction.
We recommend measuring shoring deflection during excavation to monitor the magnitude of
movement in response to excavation depth, and to detect continued movement without additional
excavation or other responses that would be cause for concern. We recommend monitoring
deflection using inclinometers and/or optical survey methods. These methods have been proven
accurate and reliable, and would allow the stakeholders to establish deflection threshold values
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which would trigger prescribed responses intended to prevent excessive deflection or shoring
failure.
9.5 Wet Weather Earthwork
Wet weather generally begins about mid -October and continues through about May, although
rainy periods may occur at any time of year. The soil at the site contains sufficient fines content
to produce an unstable mixture when wet. Such soils are susceptible to changes in water content,
and tend to become unstable and difficult, or impossible, to compact if their moisture content
exceeds the optimum. If earthwork at the site continues into the wet season, or if wet conditions
are encountered, we recommend the following:
The ground surface in and surrounding the construction area should be sloped as
much as possible to promote runoff of precipitation away from work areas and to
prevent ponding of water.
Earthwork should be accomplished in small sections to minimize exposure to wet
conditions. That is, each section should be small enough so that the removal of
unsuitable soils and placement and compaction of clean structural fill can be
accomplished on the same day. The size of construction equipment may have to be
limited to prevent soil disturbance. It may be necessary to excavate soils with a
backhoe, or equivalent, located so that equipment does not traffic over the excavated
area. Thus, subgrade disturbance caused by equipment traffic will be minimized.
■ Fill material should consist of clean, well -graded, pit -run sand and gravel soils of
which not more than 5 percent fines by dry weight passes the No. 200 mesh sieve,
based on wet -sieving the fraction passing the 3/4-inch mesh sieve. The gravel content
should range between 20 and 60 percent retained on a No. 4 mesh sieve. The fines
should be nonplastic.
■ No soil should be left uncompacted and exposed to moisture. A smooth -drum
vibratory roller, or equivalent, should roll the surface to seal out as much water as
possible.
■ In -place soils or fill soils that become wet and unstable and/or too wet to suitably
compact should be removed and replaced with clean, granular soil (see third bullet).
■ Excavation and placement of structural fill material should be observed on a full-time
basis by a geotechnical engineer (or representative) experienced in earthwork to
determine that all work is being accomplished in accordance with the project
specifications and our recommendations.
■ Grading and earthwork should not be accomplished during periods of heavy,
continuous rainfall.
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■ We suggest that these recommendations for wet weather earthwork be included in the
contract specifications.
9.6 Erosion Control
The Contractor should employ proper erosion control measures during construction, especially if
construction takes place during wet weather. Covering work areas, soil stockpiles, or slopes with
plastic and using sandbags, sumps, and other measures should be employed as necessary to
permit proper completion of the work. Bales of straw, geotextile silt fences, rock -stabilized
entrance, wheel wash (as appropriate), street sweeper, and drain inlet sediment screens/collection
systems should be appropriately located to control soil movement and erosion.
10.0 ADDITIONAL SERVICES
We recommend that Shannon & Wilson be retained to review the geotechnical aspects of plans
and specifications to determine that they are consistent with our recommendations. In addition,
we should be retained to observe the geotechnical aspects of construction, particularly
foundation installation, shoring design, drainage and backfill. Observation will allow us to
evaluate the subsurface conditions as they are exposed during construction and to determine that
the work is accomplished in accordance with our recommendations and the project
specifications.
11.0 LIMITATIONS
This report was prepared for the exclusive use of Snohomish County Parks and their
representatives for the Meadowdale Beach Park Estuary Restoration Project. The
recommendations in this report supersede those provided in all previous versions of this report,
and those provided via email or other correspondence before this report was published. This
report should be provided to prospective contractors for their information, but our report,
conclusions, and interpretations should not be construed as a warranty of subsurface conditions
included in this report.
The analyses, conclusions, and recommendations contained in this report are based on site
conditions as they presently exist, and further assume that the explorations are representative of
the subsurface conditions throughout the site; that is, the subsurface conditions everywhere are
not significantly different from those disclosed by the explorations. If subsurface conditions
different from those encountered in the explorations are encountered or appear to be present
during construction, we should be advised at once so that we can review these conditions and
reconsider our recommendations, where necessary. If there is a substantial lapse of time between
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the submission of this report and the start of construction at the site, or if conditions have
changed because of natural forces or construction operations at or adjacent to the site, we
recommend that we review our report to determine the applicability of the conclusions and
recommendations.
Within the limitations of scope, schedule, and budget, the analyses, conclusions, and
recommendations presented in this report were prepared in accordance with generally accepted
professional geotechnical engineering principles and practice in this area at the time this report
was prepared. We make no other warranty, either express or implied. These conclusions and
recommendations were based on our understanding of the project as described in this report and
the site conditions as observed at the time of our explorations.
Unanticipated soil conditions are commonly encountered and cannot be fully determined by
merely taking soil samples from test borings. Such unexpected conditions frequently require that
additional expenditures be made to attain a properly constructed project. Therefore, some
contingency fund is recommended to accommodate such potential extra costs.
The scope of our present work did not include environmental assessments or evaluations
regarding the presence or absence of wetlands, or hazardous or toxic substances in the soil,
surface water, groundwater, or air on or below or around this site, or for the evaluation or
disposal of contaminated soils or groundwater should any be encountered.
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Shannon & Wilson has prepared and included Appendix E, "Important Information About Your
Geotechnical/Environmental Report," to assist you and others in understanding the use and
limitations of our reports.
SHANNON & WILSON, INC.
STo
42481
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Tyler Stephens, PE
Associate
SAW:AJD:TJS:RAM:NDM/saw
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12.0 REFERENCES
American Association of State Highway and Transportation Officials (AASHTO), 2016,
AASHTO LRFD bridge design specifications: U.S. customary units (7th ed. with 2015
and 2016 interim revisions): Washington, D. C., AASHTO, 2 v.
American Institute of Steel Construction (AISC), 2011, Steel construction manual (14th
ed.): Chicago, Ill., American Institute of Steel Construction, 1 v.
American Railway Engineering and Maintenance -of -Way Association (AREMA), 2016, Manual
for railway engineering: Landover, Md., AREMA, 7 v.
American Society of Civil Engineers (ASCE), 2013, Minimum design loads for buildings and
other structures (3rd printing): Reston, Va., American Society of Civil Engineers, ASCE
Standard ASCE/SEI 7-10.
Anchor QEA, 2017, Meadowdale Beach Park history: Personal communication (project
conference call) between Snohomish County Parks, Anchor QEA, Hanson Professional
Services, ICF, Shannon and Wilson, Seattle, Washington, January 12.
Applied Geotechnology Inc., 1986: Available:
hgps:Hfortress.wa. ovg /dnr/geology/?Theme=subsurf, Borehole ID 60442, Document
ID10996, accessed 11/2014.
ASTM International (ASTM), 2014, Annual book of standards, Construction v. 04.08, Soil and
rock (I): D420 — D5876: West Conshohocken, Penn., ASTM International, 1 v.
Dailer, Doug, 2014, Meadowdale Beach Park history: Personal communication (in -person
conversation) between Doug Dailer, Meadowdale Beach Park resident ranger for
Snohomish County, Washington and Stephanie Williams and Bill Laprade of Shannon
and Wilson, Seattle, Washington, December 4.
Geo-Slope International, 2016, SLOPE/W 2016: Calgary, Alberta, Geo-Slope International.
Global Geophysics, 2016, Report for the ground penetration radar survey at Meadowdale Beach
Park, Edmonds, WA: Report prepared by Global Geophysics, Redmond, Wash.,
105-0419.001, for Shannon & Wilson, Inc., Seattle, Wash., December 7.
Global Geophysics, 2017a, GPR survey line location map (fig. 1-A) and interpreted GPR
anomalies (fig. I-B) [rev.], in, Report for the ground penetration radar survey at
Meadowdale Beach Park, Edmonds, WA: Report prepared by Global Geophysics,
Redmond, Wash., 105-0419.001, for Shannon & Wilson, Inc., Seattle, Wash., February 7.
21-1-22288-060-R1 Fwp/]kn 21-1-22288-060
37
SHANNON WALSON, INC.
Global Geophysics, 2017b, Report for the ground penetration radar and electrical resistivity
tomography surveys at Meadowdale Beach Park, Edmonds, WA: Report prepared by
Global Geophysics, Redmond, Wash., 105-0419.002, for Shannon & Wilson, Inc., Seattle,
Wash., May 1.
International Code Council, Inc., 2014, International building code 2015: Country Club Hills,
Ill., International Code Council, Inc., 700 p.
Intlekofer, C. F., 1989, Construction of Great Northern's seawall and double track between
Seattle and Everett, Washington: Great Northern Railway Historical Society Reference
Sheet no. 156, p. 1-8, December.
Minard, J.P., 1983, Geologic map of the Edmonds East and Part of the Edmonds West
quadrangles, Washington: U.S. Geological Survey Miscellaneous Field Studies Map
MF-1541, scale 1:24,000.
Pile Dynamics, Inc., 2010, GRLWEAP, one-dimensional wave equation analysis: Cleveland,
Ohio, Pile Dynamics, Inc.
Pin Foundations, Inc., 2018, Diamond Pier foundation system use and applications: Gig Harbor,
Wash., Pin Foundations, Inc., 1 p.,
available: http://pinfoundations.com/images/pdf/2018/DP%2OUse%20and%2OApplications
_2018.pdf.
Reese, L. C.; Wang, S. T.; Isenhower, W. M.; and Arrellaga, J. A., 2016, LPILE v. 2016.9.10:
Austin, Texas, Ensoft, Inc.
Shannon & Wilson, Inc., 2015, Meadowdale Beach Park Geotechnical Feasibility Study,
Geologic Assessment, and Sediment Loading, South Snohomish County, Washington:
report prepared for Anchor QEA, LLC, project no. 21-1-22034-001.
Shannon & Wilson, Inc., 2016, Meadowdale Beach Park feasibility study, preliminary
geotechnical assessment addendum, south Snohomish County, Washington: Report
prepared by Shannon & Wilson, Inc., Seattle, Wash., 21-1-22034-001, for Anchor QEA,
LLC, Seattle, Wash., February.
Shannon & Wilson, Inc., 2017, Geologically hazardous areas, Meadowdale Beach Park estuary
restoration project, Snohomish County, Washington, draft: Report prepared by Shannon
& Wilson, Inc., Seattle, Wash., 21-1-22288-040, for Snohomish County Parks &
Recreation, Snohomish, Wash., April.
Snohomish County, Wash., Department of Planning & Development Services (SCDPDS), 2006,
Standards for construction of pin piles for foundation construction: Rule 5660, 2 p.,
August 15, available: htt2s://snohomishcountywa.gov/documentcenter/view/9876.
21-1-22288-060-R1 f/wp/]kn 21-1-22288-060
38
SHANNON WALSON, INC.
Thorson, R.M., 1989, Glacio-isostatic response of the Puget Sound area, Washington:
Geological Society of American Bulletin, v. 101, no. 9, p. 1163-1174.
U.S. Geological Survey (USGS), 2017, U.S. seismic design maps: Available:
http://earthquake.usgs.,gov/desi rg i aps/us/Nplication.php, accessed June, 2017.
Washington State Department of Transportation (WSDOT), 2015, Geotechnical design manual:
Olympia, Wash., WSDOT, Manual M 46-03, 1 v., May, available:
http://www.wsdot.wa.gov/Publications/Manuals/M46-03.httn.
21-1-22288-060-R1 Fwp/]kn 21-1-22288-060
39
SHANNON MLSON, INC.
TABLE 1
AREMA 2016/ASCE 7-10
PARAMETERS FOR SEISMIC DESIGN OF STRUCTURES
SITE CLASS E
Return Period
(AREMA Level)
Ma nitude
Sa T=o
SnS
� �&
100- ear I
6.6
0.20
0.45
0.19
475- ear (11)
6.8
0.24
0.61
0.45
2,475- ear (lIl)
7.0
0.48
0.89
0.84
Notes:
ASCE = American Society of Civil Engineers
AREMA = American Railway Engineering and Maintenance of -Way Association
21-1-22288-060-Rif Tiiwpilkn 21-1-22288-060
SHANNON & WILSON, INC.
TABLE 2
RECCOMMENDED L-PILE PARAMETERS
Total Unit
Effective
Modulus of Subgrade Reaction,
Undrained Shear
Strain at 50%
Approximate
Approximate
Weight,
Unit Weight,
Friction Angle, (D
k
Strength, S.
Maximum
Top Elevation
Bottom Elevation
USCS
Geologic
Soil
y
y'
(degrees)
(pci)
(psf)
Stress, 650
Static/Seismic
Liquefied
Static/Seismic
Liquefied
Static/Cyclic
Location (Boring)
(feet)
I (feet) JClassification
Unit
Model
(pet)
(pci)
Static/Uyclic
Sand
13
3.5
ML to SM
Ha, Hc, Hf
115
53
26
5
10
2
-
(Reese/API)
3.5
-37
SM to SP-SM to
Ha, He
Sand
125
63
33
33
75
75
--
-
Railroad Bridge, S. Abutment (MB-6)
GP -GM
(Reese/API)
Stiff Clay
-37
-117.8
SP to ML
Qpnl
without Free
130
68
--
--
125
125
6000
0.010
Water
Sand
14
-1
ML to SM
Ha, Hc, Hf
115
53
26
26
10
10
--
--
(Reese/API)
-1
-34
ML to SP-SM to
Ha, He
Sand
125
63
32
32
65
65
--
--
Railroad Bridge, N. Abutment (MB-7)
GP -GM
(Reese/API)
Stiff Clay
-34
-106
GP -GM to SM
Qpnl
without Free
130
68
--
--
125
125
6000
0.010
Water
Structural Fill/Ha,
Sand
24
7
SM
115
53
34
34
60
60
--
--
Hc, Hf
(Reese/API)
Pedestrian Bridge (MB-8 [Mitigated Condition])
Sand
7
-2.5
ML to SM
Hc, Qvro
125
63
36
36
80
80
--
(Reese/API)
Notes:
The ground surface elevations were estimated from file titled: 16-2604Topo 4-21-17.dwg
Assume ground water table at ground surface
pcf = pounds per cubic foot, pci = pounds per cubic food, psi = pounds per square inch, psf = pounds per square foot
These parameters were developed using the subsurface conditions encountered in the project borings, published correlations, and engineering judgment.
21-1-21882-060
T2 - LPile Parameters
" i9n 1 tM
o. Li;nco a i,• t. 4.
/n- a 4}
/ ejby.�a E ? t w
�- �-Norma-Beach R?d Q a
Fisher-,�
Meadowdal
Beach Park
68th St=SW
•� t e 'J: Cl
761 51 S'A'
• rn� . -
zil
_.
> rn Dr-
Q Co
DIr
�> CC)
'. 1 _• <
_6••t4tn st s
Main-s/, ' "208th St�SW :�� 1 at�h
Dayton .St_ a ' N �, J
�_ i! Y' 0 0
6owaorn is C � - T ' c -212th Sl-S G 1>1
< F L D
o `v° _r1_ is , a;, ,i rn� 00
ee C;Ed,•.:. �,.1' r cD IIII� -- 228th-S
Gy 00^. a R� c0 J
� I• �fGc � - ��G it _� ti' - �i'1\
rnr„�Q - Dry-236th-St-SW* -i Mail lid 1
02
O
N
M
N
O
N
f0
w
3
A
A'
40
40
M B-7
M B-6
CULVERT LOCATION
(Proj. 1' E)
(Proj.
1' W)
20
20
S&W BORING LOG LEGEND
f
s
I4
MB-7 Boring Designation
Q
I9
(Proj. 1' E) Projection (Distance and Direction)
Hf, Ha/He Upper
.
I2
I 1
Ground Surface
0
� �
0
;
26
•.
124
123
`
•.
:
12s
I22
I 5 Sample Penetration Test in Blows/Foot
145
= 50/3" or Blows/Foot Driven
135
I18
Approximate - Water Level
Water Level
o
I23
During Drilling
-20 -
2e
26
i
14
-20
162
•,
125 Ha/Hc Lower
I39
--
<
132
121
x
M
= 10016
cD
< -40 -
�
?
59
-40
162
0
0
S 5016
177
(D
CD
o
132
(p
170 ?
x
Ise
Geologic Unit USCS Symbol
I e1 �
-60 —
-60 ? ? Approximate Geologic Contact
123
o
176 Qpnf and Qpnl i
I91
Bottom of Boring
'
192
06-19-13 Date of Completion
a
= 5ols
190
170
-80
K91
-80
164
176
S 5016
15016
o
S 5016
15014
= 5015
-100
I
=50/6
-100 0 20 40
= 5015.5
= 5014
04-21-17
Scale in Feet
o
= 5015
5014.5
Meadowdale Beach
-120 -
04-14-17
- -120 Park and Estuary Restoration
Snohomish County, Washington
-130 -,
- -130 GENERALIZED SUBSURFACE
0 20
40 60 80 100 120 140 160 170
PROFILE A -A'
Distance (feet)
February 2018 21-1-22288-060
(���SI-�ivtvVU�I►v F 1 G. 4
w
0)
West
30 F--
10
0
BNSF No -Drill Zone
M1
B'
4 Ft.
5° Zone 2 Zone 1
IZone 4 4Zone 3
I
I
i
0+10 0+20 0+30 0+40 0+50 0+60 0+70
ZONE 1
0-4 ft. Light Brown, Poorly Graded Sand with Gravel (SP); moist;
medium to fine sand; fine gravel; Holocene Fill (Hf)
Smooth drill action.
ZONE 2
4-19 ft. Light Brown, Poorly Graded Sand with Gravel (SP); moist;
medium to find Sand; fine to coarse gravel; Holocene Fill (Hf) Smooth
drill action. Increasing gravel content.
ZONE 3
19-34 ft. Light Brown, Poorly Graded Gravel with Sand, (GP); moist;
coarse to fine gravel; medium to fine Sand; Holocene Fill (Hf)
Slightly rough drill action. Some rig chatter.
ZONE 4
34-37 ft. Light Brown, Poorly Graded Gravel with Sand (GP); moist;
coarse to fine gravel; medium to fine sand; Holocene Fill (Hf)
Rough drill action. Slower advance rate and rig chatter.
0 10 20
Scale in Feet
0+g0
LEGEND
Sand with Gravel
Gravel with Sand
East
1 30
m
am
u_
20
0
m
w
10
0+g0 1+00
NOTE
Figure adapted from client file,
16-2604Topo_4-21-17.dwg, dated 4-21-17.
Transect 1
GPR anomaly GPR anomaly GPR anomaly
GPR anomaly GPR anomaly Distance (ft)
Zone of boulders and gravels
GPR anomaly
0ftN 20ftN 40ftN �'60 ftN �80ftN
100ftN,� `�� 120ftN ��`� �- 140ftN 160ftN 180ftN
200ftN 220ftN 240ftN 260ftN 280ftN 300ft
0ft
10 ft'
CL
�..
-
-
"
❑
20ft ;i;.;: ��.f•�...�..�. •�-,•-..1.:i-- .' ♦w
•f •• -<.r t• !•-#
f f�• r ' -OMM-
�101A►i�l. J•tl•:�'l �Y�r e.aa. p�rsll•s♦ t•��_.
.- .
i. ,• -. ••.••� 1• ►i1li •--- •-........'.- J�-
`•!•••�.ei # \�..>• � ��,•f.,
�.i + t±k aa� .•aas+�VIt:6*
kl.sa - sfi.�> ti.
tf�`. -.3. ?
30 ft .i+sa�t _ , �aca4...
�.ra> �. I-= - R
_. i•,''�`�
Bottom of fill?
Transect 2 GPR anomaly
GPR anomaly Distance ft
O GPR
GPR anomaly
anomaly y GPR anomaly,
OftN 20ftf�1� 40fi�1 60ftN 80ftN
100ftN 120ft1�J \ 140ftN 160ftN 180ftN
;.,200ftN 220ftN 240ftN 260ftN �\ 280ftN'�, 300ft
Oft
_
ti
-
ice-.
Q
• �i�.I ��. _ _ -
�`-:: ' - - ---
" -_: �
- - - __ •./� �'V���
_ _- . _ - - _ - - --
- �'+' ,� r v���! • .1r.',' �� • -'•
s = �.�"� - .:•::: � -
0
20ft � -- _ . . -_ . -, . _ --
. -- _
- -- .. :::• _ _ • , , -
*l a Rr s-rahi: sis!'
4i of
. .
30 ft
Transect 3 GPR anomaly GPR anomaly \
GPR anomaly Distance (ft) GPR anomaly
Bottom of fill?
0ftN 20ftN 40ftN ��6 ftN\ 80ftN
100ftN 120ft_N-- 140ftN 160ftN ����'���-1:80ftN
200ftN 220ftN 240ftN 260ftN 280ftN 300ft
0 ft
-- - - -
- --
-
- `~10
_ _ _
'- __' ~ �- - ° - �./! - =vim -_- -� .+�r�r•r. �- = -.+ - �� _ _ ti^`� -� - �`+•_�_ - _ _
•^
-_ z -. - �.��-- .. - O-' -'.. r.-,�_
! _ ' .�
�. _ - .-. `.'. - . ^- . r. ^. it -+. -. _ _ - -
ft
-
""-�
"^.- �:�•�� �:'��'' "'
0
2aft
Zone of coarse materials, = _
- _ �:. �.. i i l,' -`— _'` =�-' - -
such as boulders and gravels
V ` ���r.•��•`+ir w .- ` Mi • a+
.ter
_ - —
w
''
30 ft-
•." *•o-'N'.a. - _ ♦ -
r �'-�� - • s'' ti x -r•ra _'f►3 .:+. - ,...,
GPR anomal GPR anomaly GPR anomal
Transecty
4 Y
GPR anomaly Distance ft GPR anomaly
, P O � Y
Bottom of fill?
0ftN 20ftN, ���A 40ftN /I� 60ftN� 80ftN
10 ftN 120ftN 140ftN 160ftN • �_180ftN
200ftN 220ftN 240ftN 260ftN 280ftN 300ft
/' U-----
L
0 ft
- -
��- HB-1
10 ft
-
❑
20ft
' • -_ - � - "_ - _ - . �� _ ;ter - _ __ �_-....
_ _•`._ �. � -
_:_ _
:
Meadowdale Beach
0 20 40
Park and Estuary Restoration Project
Snohomish County, Washington
Approximate Scale in Feet
GPR PROFILES WITH
NOTES
LEGEND
HORIZONTAL BORING LOCATION
1. Location of horizontal boring scaled from field measurements.
HB-1 Q Horizontal Boring Designation
February 2018 21-1-22288-060
2. Figure adapted from Global Geophysics, 2017b.
and Approximate Location
J�9I-X4N0hI&WL9MlI�
FIG.6
3
a�
0
a`
T
N
N
a
N
N
C
m
U-
0
co
00
N
N
O
ID
co
co
N
I
Transect 2
Distance (ft)
0 ft
20 ft
40 ft
60 ft 80 ft 100 ft
120 ft 140 ft 160 ft 180 ft 200 ft 220 ft 240 ft
260 ft 280 ft 300
20ft
10ft
-
0 ft
�.
-�
-
:
-10 ft
-20 ft-�
Transect 4
Distance (ft)
0 ft
20 ft
40 ft
60 ft 80 ft 100 ft
120 ft 140 ft 160 ft 180 ft 200 ft 220 ft 240 ft
260 ft 280 ft 300
20ft
1
~ mil-�'
— _
--------- �L-_
oft
": -
16
_ _ '
LU
-20 ft
E E E E
E E E E E E
� t t E
E E E E E E E
E E
E E E E E E
O O O L
O
L L L L L L
O O O O O O
E E E E
v M�
� 0 oo M
0 0 M 0 0 � O
O O
O O J- J- L s
O O O O
O�� M
N 0 1-
M (O
O O N M O � 0
O M � 0 M N
N N W
f`-w
W W
V N
O O
r- O 0 0 � N
0 M N �
Meadowdale Beach
0 20 40
Park and Estuary Restoration Project
Snohomish County, Washington
Approximate Scale in Feet
INVERTED RESISTIVITY PROFILES
NOTES
WITH HORIZONTAL BORING
1. Location of horizontal boring scaled
from field measurements.
LEGEND
LOCATION
HB-1 Q Horizontal Boring Designation
February 2018 21-1-22288-060
2. Figure adapted from Global Geophysics,
2017b.
and Approximate Location
FEUISHMNON&WILREKINARM
FIG. 7
2/14/2018-MB-6_with_RR_emabnkment_fill_unplugged_TJS FINAL 14FEB2018 mfc/
ASSUMED SUBSURFACE
STATIC CASE
SEISMIC CASE
PROFILE
AXIAL CAPACITY (tons)
AXIAL CAPACITY (tons)
0
100 200 300 400 500
600
0
100 200 300 400 500 600
o'
0
0
!
6'
Ultimate
ate Side
10
— Ultimate Side
Assumed Liquefied Z one
q
_...._...._...
-----
11.5'
---- Ultimate Base---
I I
Ultimate Base
20
Allowable Total (Compression)
----- ---------T--------
20
____________- Allowable Total (Compression)
.............. Allowable Total (Uplift)
I I
�> Allowable Total (Uplift)
is
I I
1$
I I I
I I
I I I I
40
1......_......_.._._._._.
!._. _.
40
_...--.._.._..._..._..._.+_..._..._..._..._..._..._..._..._..._......_..._..------- -------.-.._...--------------------
! I I I
a�
I !
Assumed I ue le Zone
q
I I I I
50,
v
50_.
_. _ _.-.-.-.- _- _. _. _._.._.._._._._._.
LU
o
60
--- ------ ---T
a
60
Add Downdrag Loads to Other
Foundation Loads
a
1-.....-
T T
_
1
w1
w
1
(see Seismic Case Note 3)
J
1
a
70
1
1
_- -.- -.-. -- -.-.-. --.-.-.-.-.-.-.-.-.+ .-.-.-.-..----I----------4----------
a
70
- -
1
` j II II j
1
1
I
I.-.-.-.-.-—.-.-.-.-
80---
---------- - - - - - - - - -------------------
---------
1
1
! � II II I
1
II II I
90
1
_....._....._
................................i............_..._._._._._._._.I-.-.-.-.-.-.-.+.-.-.-.-.-.-.-.-.-.--.-.-.-.-.-.-.-.-.-. .-.-.-.-.-.-.-.-.-.
90
-1
1 ...._.
_.._..----------4------------------------------�---------
I I I I
100
` 1------------------
_._._ _ _....._ _._._--.-.-.-.-.--<-.I .-.-.... I- T
100
r-
- -- —` — -- --------- -- I-------- ----I- -------- -
- r S - -- -- - --
1
1
1
` I
1
1
— r-
-- - - — -- -- -- -- -- ---
�. _
`
1
`
1
120
1
' I
-- - - I -
120
F
-- - - - - - i -
1
130
130
STATIC CASE NOTES:
SEISMIC CASE NOTES:
1. Factor of Safety of 2.0 pplied for Allowable Total (Compression)
1. Factor of Safety of 2.0 applied for Allowable Total (Compression).
2. Factor of Safety of 3.0 applied for Allowable Total (Uplift)
3. Ultimate downdrag force is estimated to be 30 tons. Downdrag force is recommended
to be applied with post -earthquake loading.
GENERAL NOTES
Meadowdale Beach
1.
The analyses were performed based on guidelines included in AREMA and local experience.
The analyses are based on a single
pile and
do not consider group Park and Estuarty Restoration Project
action of closely spaced piles (closer than 2.5 diameters, center to center).
Snohomish County, WA
2.
Allowable total pile capacity shown on plots is determined by adding its ultimate side and base resistances dividing by the appropriate factors of safety as noted
above.
ESTIMATED AXIAL PILE CAPACITY
HP 14x89 DRIVEN PILE
MB-6
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. 8
Geotechnical and Environmental Consultants
Railroad Embankment Fill
Loose Alluvium
Medium Dense Alluvium
Whidbey Formation
2/15/2018-MB-7_with_RR_Emban kment_ fill_unplugged_liquefiable_TJS FINAL 14FEB2018
mfc/F
ASSUMED SUBSURFACE
PROFILE
0'
6'
21'
54'
83'
Railroad Embankment Fill
Loose Alluvium
Medium Dense Alluvium
Dense to Very Dense
Alluvium
Very Dense Whidbey
Formation
Boring Extends to 122.0 feet
17
STATIC CASE
AXIAL CAPACITY (tons)
0 100 200 300 400 500 600
0
10
20
30
40
50
x
IL
IL
w
60
a
F-
LU
a 70
80
90
100
110
120
130
- Ultimate Side
---- Ultimate Base
- ------------
-
Allowable Total (Compression)
`
t----
— ---- --
--- -
Allowable Total (Uplift)
P
III
I I
-
-ii-
---- -
- -- -
1
I
1
1
--
i
it
i
1-- -- - --
-ill
- -- -- ---
-
t
1
!
I
I
1
II �
` �
II
1
;.-.-.-._.._.._....-ii---
I
------ -----
I
---------------------------------
I I
1
I
`I
1
I
II II
----------------_..-- -----------
�----------------
L---------
L
1
1
I
I
I �
II II
1
1
I
I
SEISMIC CASE
AXIAL CAPACITY (tons)
0 100 200 300 400 500 600
0
10
20
30
40
w
x 50
H
a
w
a 60
H
w
a 70
80
90
100
110
120
130
........... _... _.+_ ... _... _ ----
Assumed Liquefied Zone
Ultimate Side
- Ultimate Base
Allowable Total (Compression)
Allowable Total (Uplift)
.........
Add Downdrag Loads to Other
Foundation Loads
(see Seismic Case Note 3)
STATIC CASE NOTES: SEISMIC CASE NOTES:
1. Factor of Safety of 2.0 applied for Allowable Total (Compression) 1. Factor of Safety of 2.0 applied for Allowable Total (Compression)
2. Factor of Safety of 3.0 applied for Allowable Total (Uplift)
3. Ultimate downdrag force is estimated to be 40 tons. Downdrag force is recommended
to be applied with post -earthquake loading.
GENERAL NOTES Meadowdale Beach
1. The analyses were performed based on guidelines included in AREMA and local experience. The analyses are based on a single pile and do not consider group Park and Estuarty Restoration Project
action of closely spaced piles (closer than 2.5 diameters, center to center). Snohomish County, WA
2. Allowable total pile capacity shown on plots is determined by adding its ultimate side and base resistances divided by the appropriate factors of safety as noted
above. ESTIMATED AXIAL PILE CAPACITY
W
w
0
0 0
m
0
Existing Railroad Tracks —\
H=10
D, = 15
D2 = 25
NOTES
�-33 D2--�--29 Dj--� 1 300 D2 } 360 DZ---�
Active Passive
Recommended Earth Pressures for Sheet Pile Wall
Not to Scale
1. All earth pressures are in units of pounds per square foot.
2. Wall embedment (D) should consider kickout resistance. Embedment
should be determined by satisfying horizontal static equilibrium about the
bottom of the pile. Minimum recommended embedment is 10 feet below
bottom of excavation.
3. The recommended pressure diagrams are based on a continuous wall
system.
4. Pressures assume that there is no difference in water levels on either side
of the wall.
5. Passive pressures shown above include a factor -of -safety of 2.0.
6. Cooper E 80 surcharge q= 1880 psf, See Figure 11.
7. The pressure diagrams are based on a continuous wall system. If soldier
piles with laggings are used, apply active pressure over the width of the
soldier piles below the bottom of the excavation and apply passive
resistance over three times the diameter of the piles or the spacing of the
piles, whichever is smaller.
LEGEND
H = Exposed Wall Height (10 Ft. Maximum)
Di = Thickness of Hf (15 Ft. Maximum)
D2 = Thickness of He (25 Ft. Maximum)
8. Design lagging for 50% of lateral earth, seismic, and surcharge
pressures.
T
0
Q
0
N
N
0
0
z=nH
H
Bottom of
Excavation
ix=mH QP
ELEVATION VIEW
Point Load
in Pounds
(see Note 3)
GH (psf)
6H = Lateral Pressure
For m <_ 0.4: 6H = 0.28 P n z
H2 (0.16 + n2)3 (psf) (see Note 3)
Q mznz
Form > 0.4: 6H = 1.77 H2 (m2 + n2)3 (psf)
iin
Dot
3)
ELEVATION VIEW
For m <_ 0.4: 6H = 0.20 Qi n 2 2 (psf) (see Note 3)
H (0.16 + n )
z
For m > 0.4: GH = 1.28 �� m n (psf)
H (mz + nz)z
B) LATERAL PRESSURE DUE TO LINE LOAD
i.e. NARROW CONTINUOUS FOOTING
PARALLEL TO WALL
(NAVFAC DM 7.02, 1986)
Bottom of
Excavation
W
Earth rH
Berm
Note: W < 33'
Hs < 15 Feet
y = Unit Weight
cu of Earth Berm
EARTH BERM
(K)(y)(Hs)
= 2
(see Note 4)
0.0 -
0.5 -
m
N
0
m 1.0-
LL
a
m
0
1.5-
2.0 -
IP, Influence Factor
0.5 1.0
L
2B=05 L =0.25
L = 1 2B
2B
L=�
2B
Lateral Footing
Pressure on Wall
off = 2(lp) qs
cu
Bearing
Pressure
Wall Line qs
V2
2
B FCYH
z
E) LATERAL PRESSURE DUE
TO ADJACENT FOOTING
(see Notes 5 and 6)
�s (psf) (derived from NAVFAC DM 7.02,
1986; and Sandhu, Earth Pressure
on Walls Due to Surcharge, 1974)
1. Figures are not drawn to scale.
2. Applicable surcharge pressures should be
added to appropriate permanent wall lateral
Point Load Bearing earth and water pressure.
in Pounds Pressure
3. If point or line loads are close to the back of
q (psf) the wall such that m <_ 0.4, it may be more
appropriate to model the actual load
Q E7aH = (K)qs (see Note 4) distribution (i.e., Detail E) or use more
P , rigorous analysis methods.
0 a Bottom of 4. See text for recommended K values.
Excavation
`6 5. The stress is estimated on the back of the
wall at the center of the length, L, of loading.
UNIFORM SURCHARGE
6,H 6. The estimated stress is based on a Poisson's
ratio of 0.5.
i = GH COS (1.10) (psf)
A) LATERAL PRESSURE DUE TO POINT LOAD
i.e. SMALL ISOLATED FOOTING OR WHEEL LOAD
(NAVFAC DM 7.2, 1986)
in radians
GH = �p ((3 - sin R cos2a) (psf)
C) LATERAL PRESSURE DUE TO STRIP LOAD
(derived from Fang, Foundation
Engineering Handbook, 1991)
D) LATERAL PRESSURE DUE TO EARTH BERM
OR UNIFORM SURCHARGE
(derived from Poulos and Davis, Elastic Solutions for
Soil and Rock Mechanics, 1974; and Terzaghi and
Peck, Soil Mechanics in Engineering Practice, 1967)
2/16/2018-MB-8_2 inch diameter_unplugged_TJS FINAL 14FEB2018
mfc
ASSUMED SUBSURFACE
PROFILE
0'
7'
17'
Structural Fill
Soft to stiff
Alluvium/Colluvium
Medium Dense
Colluvium/Whidbey
Formation
Boring Extends to 26.S feet
STATIC CASE
AXIAL CAPACITY (tons)
0 1 2 3 4 5
0
2
4
6
8
m
JT
10
F-
0-
w
a 12
H
w
J_
a 14
16
18
20
22
24
26
Ultimate Side
-- Ultimate Base
Allowable Total (Compression)
.............»>,. Allowable Total (Uplift)
1
1
1
1
1
1
SEISMIC CASE
AXIAL CAPACITY (tons)
0 1 2 3 4 5
0
2
4
6
8
d
= 10
H
a
w
a 12
P
w
J
a 14
16
18
20
22
24
26
1
1
1
' 1
1
1
' 1
1
1
Ultimate Side
-- Ultimate Base
Allowable Total (Compression)
Allowable Total (Uplift)
Add Downdrag Loads to Other
Foundation Loads
(see Seismic Case Note 3)
STATIC CASE NOTES: SEISMIC CASE NOTES:
1. Factor of Safety of 2.0 applied for Allowable Total (Compression) 1. Factor of Safety of 2.0 applied for Allowable Total (Compression).
2. Factor of Safety of 3.0 applied for Allowable Total (Uplift) 2. Factor of Safety of 3.0 applied for Allowable Total (Uplift)
3. Ultimate downdrag force is estimated to be 0 tons. Downdrag force is recommended to
be applied with post -earthquake loading.
GENERAL NOTES Meadowdale Beach
1. Estimated axial capacities are based on a single pile and do not consider group action of closely spaced piles (closer than 2.5 diameters, center to center). Park and Estuary Restoration Project
Snohomish County, WA
2. Allowable total pile capacity shown on plots is determined by adding its ultimate side and base resistances dividing by the appropriate factors of safety as noted
above. ESTIMATED AXIAL PILE CAPACITY
2/16/2018-MB-8_4 inch diameter_unplugged_TJS FINAL 14FEB2018
mfc
ASSUMED SUBSURFACE
PROFILE
0'
7'
17'
Structural Fill
Soft to stiff
Alluvium/Colluvium
Medium Dense
Colluvium/Whidbey
Formation
s
STATIC CASE
AXIAL CAPACITY (tons)
0 1 2 3 4 5
0
2
4
6
8
JT
10
0-
a
w
r7
a 12
w
a 14
16
18
20
22
24
26
I
I
I
I
— Ultimate Side
... ......_.-------
.
----------------- ......
.....................
I
I
I
I
Ultimate Base
1
Allowable Total (Compression)
1
1
I
..... Allowable Total (Uplift)
''1
...{...............................1......._._._..—.—.—.—.—.—.—.—.—.—.—._.._._._..._................
1
i
............ ..................... ...................................................................................................................................................
>' 1
......�.......... ........_I........_.—.—.
1
!
1
1
i
i
1
I
i
i
I
i i
1
1
1
!
!
! !
!
!
!
!
! !
! !
L
I
I I
••
• •.16 I
•
.................... _...._.-.-.-..._.
!
�—
_._._._._._._._._._.I ._._.
r-------�----
•�._._._._._._..-.-.-.-.-.-.-.-.-.-.-.
1 r
I
I
I 1 I
I
I
1
I 7 I
I
I
I 1 I
--------- -
1
SEISMIC CASE
AXIAL CAPACITY (tons)
0 1 2 3 4 5
0
2
4
6
� 8
= 10
H
a
w
a 12
P
w
a 14
16
18
20
22
24
9R
— Ultimate Side
-- --
-- Ultimate Base
1 I !
Allowable Total (Compression)
I i
1
! � Allowable Total (Uplift)
1
1
II
I
1
r..._.._.._._.;I-----------+-----------------
!
I
1
!
I
1
I
1
!
I
II
— Add Downdrag Loads to Other
I— I - -- --- ----- -
1 Foundation Loads
1 (see Seismic Case Note 3)
1
�
!
--� -- —
!-- — — — -- --
!
— — --
-- —
i
I1
1
II
1
----------
7------------
-----------
1
I
II
'''
�.•,
` .—.—------------4—.-----------
-----------
III
•••••�'•_
i
I
1
i
I
I
I
1
I
I
I
I
I
I
1
I
I
III
I
j
I
I
1
1
I
j
I
i
1
I
I
1
I
1
!
!
STATIC CASE NOTES: SEISMIC CASE NOTES:
1. Factor of Safety of 2.0 applied for Allowable Total (Compression) 1. Factor of Safety of 2.0 applied for Allowable Total (Compression).
2. Factor of Safety of 3.0 applied for Allowable Total (Uplift) 2. Factor of Safety of 3.0 applied for Allowable Total (Uplift)
3. Ultimate downdrag force is estimated to be 0 tons. Downdrag force is recommended to
be applied with post -earthquake loading.
GENERAL NOTES Meadowdale Beach
1. Estimated capacities are based on a single pile and do not consider group action of closely spaced piles (closer than 2.5 diameters, center to center). Park and Estuary Restoration Project
Snohomish County, WA
2. Allowable total pile capacity shown on plots is determined by adding its ultimate side and base resistances dividing by the appropriate factors of safety as noted
above. ESTIMATED AXIAL PILE CAPACITY
2/16/2018-MB-8_6 inch diameter_unplugged_TJS FINAL 14FEB2018
mfc
ASSUMED SUBSURFACE
PROFILE
0'
7'
17'
Structural Fill
Soft to stiff
Alluvium/Colluvium
Medium Dense
Colluvium/Whidbey
Formation
s
STATIC CASE
AXIAL CAPACITY (tons)
0 2 4 6 8 10
0
2
4
6
8
JT
10
0-
a
W
a 12
H
W
a 14
16
18
20
22
24
26
!
I
I
I
- Ultimate Side
............................................. .......
.—.—.—.—.—.—.—.—.—.—.—.—...—.—._...........
.....................
I
I
- Ultimate Base
1
Allowable Total (Compression)
1
I
I
""""""""" Allowable Total (Uplift)
x�.......................................1............._..-
-.-.-.-.-.--------------
._._._..._............................
..................... ................................................. .........................:.........................................................................
1
!
!
! I
I
I
I
I I
1
r.....................1..............
1 1
_..i
I
i
I
i
I I
1
1
I
I
I
I I
I I
I i
!_.......---
---------------
-- - -
- - - - -----4------------ ------------
1
1
I
I
I
I
I
I I
I I
.....1..................
.-.-.-.-.-.-.-.-.-.-.-.---
.-.-.-.-.-.-.-.-.-._._..------------
.r._._._._._._._._._._._.
1
!
I
!
I
! !
I I
._._.—.—.—.—.—.—.—.—.—.-
—.—.—.—.—.—.—.—.—.—.—.—.-.—.—.—.—.—.—.—.—.—.—.—.
_...._... _... _... _... _..._...
_.------ I -.-.-.-.-.-.-.-.
I
II
I
I 1!
.. ..... ..... .._... _ _..._...-
--------
I`
-.-.-.-.-.-.-._.
I
.-.-.-...� .-..._... ......... I r-----------
I II
I`
I
I 1 1
I
I
I II
I
-
----- ---- ---
l
SEISMIC CASE
AXIAL CAPACITY (tons)
0 2 4 6 8 10
0
2
4
6
8
d
= 10
H
a
W
a 12
P
W
a 14
16
18
20
22
24
9S
Ultimate Side
-- Ultimate Base
Allowable Total (Compression)
1
I
- --
1
�
II
1
----------4------------
►----------4
I !
I
I
I
1!
11
11
I I
III I
I
I
11
I
I
I
11
I
I
11
I
li
I I
1!
Ij
STATIC CASE NOTES: SEISMIC CASE NOTES:
1. Factor of Safety of 2.0 applied for Allowable Total (Compression) 1. Factor of Safety of 2.0 applied for Allowable Total (Compression).
2. Factor of Safety of 3.0 applied for Allowable Total (Uplift) 2. Factor of Safety of 3.0 applied for Allowable Total (Uplift)
3. Ultimate downdrag force is estimated to be 0 tons. Downdrag force is recommended to
be applied with post -earthquake loading.
GENERAL NOTES Meadowdale Beach
1. Estimated capacities are based on a single pile and do not consider group action of closely spaced piles (closer than 2.5 diameters, center to center). Park and Estuary Restoration Project
Snohomish County, WA
2. Allowable total pile capacity shown on plots is determined by adding its ultimate side and base resistances dividing by the appropriate factors of safety as noted
above. ESTIMATED AXIAL PILE CAPACITY
SHANNON MLSON, INC.
APPENDIX A
SUBSURFACE EXPLORATIONS
21-1-22288-060
SHANNON MLSON, INC.
APPENDIX A
SUBSURFACE EXPLORATIONS
TABLE OF CONTENTS
Page
A.1 GENERAL...................................................................................................................... A-1
A.2 SOIL SAMPLING AND CLASSIFICATION............................................................... A-1
A.3 DRILLING MOBILIZATIONS..................................................................................... A-2
A.3.1 Access Road Borings........................................................................................ A-2
A.3.2 Bridge Borings.................................................................................................. A-2
A.3.3 Infiltration Potential Hand Borings.................................................................. A-3
A.3.4 Embankment Boring......................................................................................... A-3
A.4 TEST PIT EXCAVATION............................................................................................. A-3
A.5 REFERENCE.................................................................................................................. A-4
FIGURES
A-]
Soil Description and Log Key (3 sheets)
A-2
Log of Boring MB-1 (2 sheets)
A-3
Log of Boring MB-2 (2 sheets)
A-4
Log of Boring MB-3 (3 sheets)
A-5
Log of Boring MB-4 (3 sheets)
A-6
Log of Boring MB-5 (2 sheets)
A-7
Log of Boring MB-6 (5 sheets)
A-8
Log of Boring MB-7 (4 sheets)
A-9
Log of Boring MB-8 (2 sheets)
A-10
Log of Boring HB-1
A-11
Log of Boring HB-2
A-12
Log of Test Pit TP-1
A-13
Log of Test Pit TP-2
A-14
Log of Test Pit TP-3
A-15
Log of Test Pit TP-B
A-16
Log of Test Pit TP-RE-1
21-1-22288-060-xif aarev/wp/aya 21-1-22288-060
A-i
SHANNON MLSON, INC.
APPENDIX A
SUBSURFACE EXPLORATIONS
A.1 GENERAL
The subsurface exploration program consisted of drilling and sampling ten borings between
November 21 and June 25, 2017. The soil borings were completed in separate mobilization
efforts and will be discussed as such in the following sections:
■ Access road borings included five soil borings along the access road. These borings,
designated MB-1 through MB-5, extended to depths of 40 to 60 feet.
■ Bridge borings included two soil borings near the proposed railroad bridge abutments
and one soil boring near the proposed pedestrian bridge. These borings are
designated as MB-6 through MB-8.
Infiltration design borings included two shallow hand borings, designated HB-1 and
HB-2.
Locations of completed explorations are shown in Figure 2.
Figure A-1 presents a key to our classification of the soils encountered in the explorations. The
soil boring logs are presented as Figures A-2 through A-11. TP logs A-12 through A-16.
A.2 SOIL SAMPLING AND CLASSIFICATION
We collected disturbed soil samples with a split -spoon sampler and performed Standard
Penetration Testing (SPT) in accordance with ASTM Designation: D1586, Standard Test
Method for Standard Penetration Test and Split -barrel Sampling of Soils (ASTM, 2014). The
SPT consists of a 2-inch-outside-diameter, 1.375-inch-inside-diameter, split -spoon sampler
driven 18 inches into the bottom of the borehole with a 140-pound hammer free -falling
30 inches. The number of blows required to penetrate the final 12 inches is termed the Standard
Penetration Resistance (N-value). The field N-values are plotted in the boring logs. These
values provide an empirical means for evaluating the relative density of granular soil and the
relative consistency (stiffness) of cohesive soil. Figure A-1 shows the relative density or
consistency as it relates to the SPT N-value.
We performed SPTs at 2.5-foot intervals to a depth of 20 feet and then at 5-foot intervals
thereafter. The Shannon & Wilson field representative described each sample in the field and
21-1-22288-060-R1 f-AArev/wp/aya 21-1-22288-060
A-1
SHANNON MLSON, INC.
sealed the samples in plastic jars to preserve moisture. We stored the sample jars in boxes and
returned them to our laboratory for further analyses and testing. Sample depth intervals are
shown in the boring logs.
We collected grab samples at select depths in borings HB-1 and H-2 and at test pits TP-1 and
TP-2. Grab samples were collected directly from the auger head or the excavator bucket. We
visually classified soils in the field and stored grab samples in plastic jars or plastic bags to
preserve moisture for laboratory analyses and testing. Sample depths are shown in boring and
test pits logs.
A Shannon & Wilson representative logged each field exploration, observed the drilling and
sampling operations, retrieved representative soil samples for laboratory testing, and prepared
descriptive field logs of the borings and test pits. Representative soil samples collected were
taken to our laboratory in Seattle, Washington, for analysis. Soil samples were classified using
the method described in ASTM Designations D2487, Standard Test Method for Classification of
Soil for Engineering Purposes, and D2488, Standard Recommended Practice for Description of
Soils (Visual -Manual Procedure). These standards use the Unified Soil Classification System
(USCS). This classification system is summarized in graphical form in Figure A-1 (Sheet 2).
A.3 DRILLING MOBILIZATIONS
A.3.1 Access Road Borings
Cascade Drilling completed five soil borings using hollow -stem auger (HSA) drilling
techniques. HSA drilling consists of advancing a 12-inch-diameter, continuous flight auger with
hollow stem to facilitate sampling at specified depths. Cascade Drilling collected cuttings in
55-gallon drums and disposed of them at a licensed facility. Borings were backfilled with
bentonite chips.
A.3.2 Bridge Borings
Holt Services, Inc. (Holt) completed three soil borings using mud rotary and HSA drilling
techniques at borings M13-6 through M13-8. For boring M13-6, Holt used mud rotary drilling
techniques with a 4%8-inch-diameter drill bit to 55 feet, then switched over to a 3%8-inch-diameter
drill bit once finer -grained, glacially overridden soils were encountered for the remainder of the
boring. For boring M13-7, Holt started with a 6-inch-diameter HSA to 40 feet, then switched
over to mud rotary drilling techniques with a 5%8-inch-diameter drill bit for the remainder of the
boring. Drilling in gravelly soils in the upper 50 feet at MB-6 and 75 feet at M13-7, as well as
21-1-22288-060-x1t=aarev/wp/aya 21-1-22288-060
A-2
SHANNON MLSON, INC.
caving or collapsing of the borehole, was problematic at these locations. Boring MB-6 was
backfilled with bentonite chips from 37 feet, the depth of borehole collapse. Boring MB-7 was
backfilled with bentonite chips from 110 feet, the depth of borehole collapse. Holt drilled MB-8
to 25 feet and backfilled with bentonite chips. Holt collected cuttings in 55-gallon drums and
disposed of them at a licensed facility.
A.3.3 Infiltration Potential Hand Borings
Infiltration potential hand borings designated HB-1 and HB-2 were completed by
Shannon & Wilson staff. Shannon & Wilson staff augered to 10 and 6.5 feet at HB-1 and HB-2,
respectively, using a 4-inch-diameter auger. Wells were installed in these borings to measure
water levels at these locations for use in evaluating infiltration potential as part of evaluating
on -site stormwater infiltration feasibility. The upper 1 to 1.5 feet of the well was sealed with
bentonite and the bottom foot of the well was screened. A 6-inch-diameter irrigation box seals
the well cover at or near grade and the well remains in place for future readings. Cuttings from
the hand borings were spread out on site.
A.3.4 Embankment Boring
Kulchin Foundation Drilling Company (Kulchin) completed a single sub -horizontal
(5-degree declination) exploratory boring using air -rotary techniques. As requested by BNSF,
the boring was sited to maintain a 4-foot vertical clearance below the bottom of tie. Kulchin
advanced the boring using a Davey Drill and Sullair 900 compressor advancing a 7-inch-
outside-diameter drag bit through a cased hole. Shannon & Wilson collected samples of drill
cuttings throughout the exploration for field classification. The exploration was advanced
37 feet from the entry point. The final exploration depth had been predetermined to stop about
2.5 feet beyond the Main 1 end of tie to avoid exiting the embankment through the existing
riprap slope protection. Spoils from drilling were spread onsite and the hole was backfilled using
neat cement grout.
A.4 TEST PIT EXCAVATION
Five test pits (TPs), designated TP-1 through TP-3, TP-RE-1, and TP-B, were excavated at the
site to provide subsurface information for proposed restroom enclosure and evaluate the presence
of construction debris. The test pit logs are presented as Figures A-12 through A-16.
Exploration was performed in June 2017 by Clearcreek Contractors, Inc. under subcontract to
Shannon & Wilson. The test pits were excavated with a JD-50 mini -excavator.
21-1-22288-060-R1 f-AArev/wp/aya 21-1-22288-060
A-3
SHANNON MLSON, INC.
The relative density of the exposed soils in TP-RE-1 was estimated based on probing the bottom
of the pit with a 1/2-inch-diameter steel bar and by evaluating the ease or difficulty of the
excavation. Representative samples were collected in jars and bags, then were returned to our
laboratory for testing. Following completion of the test pits, the excavated soils were placed
back into the excavations in lifts tamped with the excavator bucket.
The enclosed Test Pit Logs are written records of the subsurface conditions encountered. The
logs graphically illustrate the geologic units (layers) encountered in the test pits and the USCS
symbol of each geologic layer. The logs also include estimated soil density, water seepage, and
construction debris where observed. Other information shown in the test pit logs includes a plot
of soil sample depth, moisture content (where tested), and approximate ground surface elevation.
A.5 REFERENCE
ASTM International (ASTM), 2014, Annual book of standards, Construction v. 04.08, Soil and
rock (I): D420 — D5876: West Conshohocken, Penn., ASTM International, I v., available:
www.astm.org.
21-1-22288-060-R1 f-AArev/wp/aya 21-1-22288-060
A-4
PARTICLE SIZE DEFINITIONS
Shannon & Wilson, Inc. (S& W), uses a soil
identification system modified from the Unified
Soil Classification System (USCS). Elements of
the USCS and other definitions are provided on
this and the following pages. Soil descriptions
are based on visual -manual procedures (ASTM
D2488) and laboratory testing procedures
(ASTM D2487), if performed.
S&W INORGANIC SOIL CONSTITUENT DEFINITIONS
CONSTITUENT 2
FINE-GRAINED SOILS
(50%or more fines)'
COARSE -GRAINED
SOILS
less than 50 /o fines
Silt, Lean Clay,
Major
Elastic Silt or
Sand or Grave l4
Fat Clay
Modifying
(Secondary)
30% or more
More than 12%
Precedes major
coarse -grained:
fine-grained:
constituent
Sandy or Gravelly'
Silty or Clayey'
15% to 30%
5% to 12%
coarse -grained:
fine-grained:
Minor
with Sand or
with Silt or
with C1aLr'_
Follows major
_ _with_Gr_av_e14 _
30 /0 or more total
_ _ _
constituent
coarse -grained and
15% or more of a
lesser coarse-
second coarse -
grained constituent
grained constituent:
is 15% or more:
with Sand or
with Sand or
with Gravels
With Gravels
'All percentages are by weight of total specimen passing a 3-inch sieve.
2The order of terms is: Modifying Major with Minor.
3Determined based on behavior.
'Determined based on which constituent comprises a larger percentage.
'Whichever is the lesser constituent.
MOISTURE CONTENT TERMS
Dry Absence of moisture, dusty, dry
to the touch
Moist Damp but no visible water
Wet Visible free water, from below
water table
STANDARD PENETRATION TEST (SPT)
SPECIFICATIONS
Hammer: 140 pounds with a 30-inch free fall.
Rope on 6- to 10-inch-diam. cathead
2-1/4 rope turns, > 100 rpm
NOTE: If automatic hammers are
used, blow counts shown on boring
logs should be adjusted to account for
efficiency of hammer.
Sampler: 10 to 30 inches long
Shoe I.D. = 1.375 inches
Barrel I.D. = 1.5 inches
Barrel O.D. = 2 inches
N-Value: Sum blow counts for second and third
6-inch increments.
Refusal: 50 blows for 6 inches or
less; 10 blows for 0 inches.
NOTE: Penetration resistances (N-values) shown on
boring logs are as recorded in the field and
have not been corrected for hammer
efficiency, overburden, or other factors.
DESCRIPTION
SIEVE NUMBER AND/OR APPROXIMATE SIZE
FINES
< #200 (0.075 mm = 0.003 in.)
SAND
Fine
#200 to #40 (0.075 to 0.4 mm; 0.003 to 0.02 in.)
Medium
#40 to #10 (0.4 to 2 mm; 0.02 to 0.08 in.)
Coarse
#10 to #4 (2 to 4.75 mm; 0.08 to 0.187 in.)
GRAVEL
Fine
#4 to 3/4 in. (4.75 to 19 mm; 0.187 to 0.75 in.)
Coarse
3/4 to 3 in. (19 to 76 mm)
COBBLES
3 to 12 in. (76 to 305 mm)
BOULDERS
> 12 in. (305 mm)
RELATIVE DENSITY / CONSISTENCY
COHESIONLESS SOILS
COHESIVE SOILS
N, SPT,
RELATIVE
N, SPT,
RELATIVE
BLOWS/FT.
DENSITY
BLOWS/FT.
CONSISTENCY
< 2
Very soft
< 4 Very loose
4-10
Loose
2-4
Soft
10-30
Medium dense
4-8
Medium stiff
30-50
Dense
8 - 15
Stiff
> 50
Very dense
15 - 30
Very stiff
> 30
Hard
WELL AND BACKFILL SYMBOLS
umBentonite
Cement Grout
%;�v;
% ' %
Surface Cement
Seal
M1
Bentonite Grout
Asphalt or Cap
EM
Bentonite Chips
Slough
Silica Sand
Inclinometer or
Non -perforated Casing
Perforated or
Screened Casing
m
Vibrating Wire
Piezometer
PERCENTAGES TERMS'' z
Trace
< 5%
Few
5 to 10%
Little
15 to 25%
Some
30 to 45%
Mostly
50 to 100%
'Gravel, sand, and fines estimated by mass. Other constituents, such as
organics, cobbles, and boulders, estimated by volume.
2Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for
Description and Identification of Soils (Visual -Manual Procedure), copyright
ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428.
A copy of the complete standard may be obtained from ASTM International,
www.astm.org.
UNIFIED SOIL CLASSIFICATION SYSTEM (USCS)
(Modified From USACE Tech Memo 3-357, ASTM D2487, and ASTM D2488)
MAJOR DIVISIONS
GROUP/GRAPHIC
SYMBOL
TYPICAL IDENTIFICATIONS
GW
I'w
* 60
Well -Graded Gravel; Well -Graded
Gravel with Sand
Gravel
GP
o C�°
Poorly Graded Gravel; Poorly Graded
Gravels
(less than 5%
fines)
(more than 50%
o p
Gravel with Sand
of coarse
fraction retained
on No. 4 sieve)
Silty or Clayey
GM
'
Silt Gravel; Silt Gravel with Sand
y y
Gravel
GC
Clayey Gravel; Clayey Gravel with
COARSE-
(more 12%
fine than
GRAINED
Sand
SOILS
(more than 50%
retained on No.
SW
Well -Graded Sand; Well -Graded Sand
200 sieve)
Sand
with Gravel
(less than 5%
fines)
SP
Poorly Graded Sand; Poorly Graded
Sands
Sand with Gravel
(50% or more of
coarse fraction
passes the No. 4
Silty or
SM
Silty Sand; Silty Sand with Gravel
sieve
Clayey Sand
(more than 12%
fines)
SC
Clayey Sand; Clayey Sand with Gravel
ML
Silt; Silt with Sand or Gravel; Sandy or
Gravelly Silt
Inorganic
CL
Lean Clay; Lean Clay with Sand or
Silts and Clays
(liquid limit less
Gravel; Sandy or Gravelly Lean Clay
than 50)
Organic
OL
—=
Organic Silt or Clay; Organic Silt or
Clay with Sand or Gravel; Sandy or
FINE-GRAINED
SOILS
— —
—
— —
Gravelly Organic Silt or Clay
(50% or more
passes the
200 sieve))
MH
Elastic Silt; Elastic Silt with Sand or
Gravel; Sandy or Gravelly Elastic Silt
Inorganic
CH
Fat Clay; Fat Clay with Sand or Gravel;
Silts and Clays
(liquid limit 50 or
Sandy or Gravelly Fat Clay
more)
Organic Silt or Clay; Organic Silt or
Organic
OH
/
Clay with Sand or Gravel; Sandy or
Gravelly Organic Silt or Clay
HIGHLY -
ORGANIC
Primarily organic matter, dark in
PT
Peat or other highly organic soils (see
SOILS
color, and organic odor
ASTM D4427)
NOTE: No. 4 size = 4.75 mm = 0.187 in.; No. 200 size = 0.075 mm = 0.003 in.
NOTES
Dual symbols (symbols separated by a hyphen, i.e., SP-SM, Sand
with Silt) are used for soils with between 5% and 12% fines or when
the liquid limit and plasticity index values plot in the CL-ML area of
the plasticity chart. Graphics shown on the logs for these soil types
are a combination of the two graphic symbols (e.g., SP and SM).
Borderline symbols (symbols separated by a slash, i.e., CUML,
Lean Clay to Silt, SP-SM/SM, Sand with Silt to Silty Sand) indicate
that the soil properties are close to the defining boundary between
two groups.
Poorly Graded Narrow range of grain sizes present or, within
the range of grain sizes present, one or more
sizes are missing (Gap Graded). Meets
criteria in ASTM D2487, if tested.
Well -Graded Full range and even distribution of grain sizes
present. Meets criteria in ASTM D2487, if
tested.
CEMENTATION TERMS'
Weak Crumbles or breaks with handling or slight
finger pressure.
Moderate Crumbles or breaks with considerable finger
pressure.
Strong Will not crumble or break with finger
pressure.
DESCRIPTION
APPROX.
PLASITICITY
VISUAL -MANUAL CRITERIA INDEX
RANGE
Nonplastic
A 1/8-in. thread cannot be rolled
< 4
at any water content.
Low
A thread can barely be rolled and
4 to 10
a lump cannot be formed when
drier than the plastic limit.
Medium
A thread is easy to roll and not
10 to 20
much time is required to reach
the plastic limit. The thread
cannot be rerolled after reaching
the plastic limit. A lump
crumbles when drier than the
plastic limit.
High
It takes considerable time rolling
> 20
and kneading to reach the plastic
limit. A thread can be rerolled
several times after reaching the
plastic limit. A lump can be
formed without crumbling when
drier than the plastic limit.
Mottled Irregular patches of different colors.
Bioturbated Soil disturbance or mixing by plants or
animals.
Diamict Nonsorted sediment; sand and gravel in silt
and/or clay matrix.
Cuttings Material brought to surface by drilling.
Slough Material that caved from sides of borehole.
Sheared Disturbed texture, mix of strengths.
Angular Sharp edges and unpolished planar surfaces.
Subangular Similar to angular, but with rounded edges.
Subrounded Nearly planar sides with well-rounded edges.
Rounded Smoothly curved sides with no edges.
Flat Width/thickness ratio > 3.
Elongated Length/width ratio > 3.
ATD
At Time of Drilling
Diam.
Diameter
Elev.
Elevation
ft.
Feet
FeO
Iron Oxide
gal.
Gallons
Horiz.
Horizontal
HSA
Hollow Stem Auger
I.D.
Inside Diameter
in.
Inches
lbs.
Pounds
MgO
Magnesium Oxide
mm
Millimeter
MnO
Manganese Oxide
NA
Not Applicable or Not Available
NP
Nonplastic
O.D.
Outside Diameter
OW
Observation Well
pcf
Pounds per Cubic Foot
PID
Photo -Ionization Detector
PMT
Pressuremeter Test
ppm
Parts per Million
psi
Pounds per Square Inch
PVC
Polyvinyl Chloride
rpm
Rotations per Minute
SPT
Standard Penetration Test
USCS
Unified Soil Classification System
q�
Unconfined Compressive Strength
VWP
Vibrating Wire Piezometer
Vert.
Vertical
WOH
Weight of Hammer
WOR
Weight of Rods
Wt.
Weight
Interbedded
Alternating layers of varying material or
color with layers at least 1/4-inch thick;
singular: bed.
Laminated
Alternating layers of varying material or
color with layers less than 1/4-inch thick;
singular: lamination.
Fissured
Breaks along definite planes or fractures
with little resistance.
Slickensided
Fracture planes appear polished or
glossy; sometimes striated.
Blocky
Cohesive soil that can be broken down
into small angular lumps that resist further
breakdown.
Lensed
Inclusion of small pockets of different
soils, such as small lenses of sand
scattered through a mass of clay.
Homogeneous
Same color and appearance throughout.
'Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for Description and
Identification of Soils (Visual -Manual Procedure), copyright ASTM International, 100 Barr
Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be
obtained from ASTM International, www.astm.org.
2Adapted, with permission, from ASTM D2488 - 09a Standard Practice for Description and
Identification of Soils (Visual -Manual Procedure), copyright ASTM International, 100 Barr
Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be
obtained from ASTM International, www.astm.org.
Meadowdale Beach
Park and Estuary Restoration
Snohomish County, Washington
SOIL DESCRIPTION
AND LOG KEY
February 2018 21-1-22288-060
SHANNON & WILSON, INC.
Geotechnical and Environmental Consultants
Total Depth: 41.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 12 in.
Top Elevation: 122.0 ft. Longitude: oDrilling Company: Cascade Drilling Rod Diam.: 8.75-in.
Vert. Datum: Station: Drill Rig Equipment: CME 75 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 lbs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
3 inches of Asphalt.
0.3
0.4
:
2 inches of Road Base.
Dense, light gray -brown, Poorly Graded Sand
with Silt (SP-SM); moist; fine sand; nonplastic
fines.
Whidbey Formation (Qpnf)
5.0
5
Dense, gray -brown, Silty Sand (SM) to Sandy
2�
Silt (ML); moist; fine sand; nonplastic fines.
Whidbey Formation (Qpnf)
3�
9.5
41
10
Dense, gray -brown, Silt (ML); moist; iron -oxide
staining; blocky texture; scattered fine sand
laminations.
Whidbey Formation (Qpnf)
5�
6
I
15
17.0
7�
Dense, gray -brown, Silty Sand (SM); moist;
fine sand; iron -oxide staining; interbeds of
sandy silt.
Whidbey Formation (Qpnf)
19.5
$�
20
Dense, gray -brown, Silt (ML); moist; trace of
21.0
fine sand; nonplastic fines; fine sand
laminations.
Whidbey Formation (Qpnl)
Dense to very dense, gray -brown, Silty Sand
(SM); interbedded with Silt (ML); moist; fine
25
sand; nonplastic fines; trace organics and
s�
63
pumice near base of unit.
Whidbey Formation (Qpnf)
0...... 20.........40........60
CONTINUED NEXT SHEET
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB- .1 1
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-2
Geotechnical and Environmental Consultants Sheet 1 of 2
67
REV 3 - Approved for Submittal
Total Depth: 41.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 12 in.
Top Elevation: 122.0 ft. Longitude: oDrilling Company: Cascade Drilling Rod Diam.: 8.75-in.
Vert. Datum: Station: Drill Rig Equipment: CME 75 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 lbs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
(n
(j
between material types, and the transition may be gradual.
0 20 40 60
X.,
,0
65
35
. .
. . . . . . . . .
38.0
X.
Dense, gray -brown, Silt (ML); moist; trace fine
sand; nonplastic fines; interbeds of fine sand.
Whidbey Formation (Qpnl)
40
,2I
41.5
BOTTOM OF BORING
COMPLETED 11/21/2016
45
50
55
0 20 40 60
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB- .1 1
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-2
Geotechnical and Environmental Consultants Sheet 2 of 2
REV 3 - Approved for Submittal
Total Depth: 41.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 12 in.
Top Elevation: 129.0 ft. Longitude: oDrilling Company: Cascade Drilling Rod Diam.: 8.75-in.
Vert. Datum: Station: Drill Rig Equipment: CME 75 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 lbs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
3 inches of Asphalt.
0.3
0.4
2 inches of Road Base.
Medium dense to dense, light gray -brown, Silty
Sand (SM) to Sandy Silt (ML); moist; fine
sand; nonplastic fines; fines content decreases
with depth; iron -oxide staining.
5
Whidbey Formation (Qpnf)
2�
31.....
9.5
41
10
Dense, gray -brown, Silt (ML) interbedded with
Silty Sand (SM); moist; fine sand; nonplastic
fines.
Whidbey Formation (Qpnf)
12.0
Dense, gray -brown, Silty Sand (SM); moist;
5�
fine sand; nonplastic fines; iron -oxide staining.
Whidbey Formation (Qpnf)
15
17.0
Very dense, gray -brown, Silt (ML); moist; trace
of fine sand; nonplastic fines.
71
8 I
Whidbey Formation (Qpnf)
- Laminated silt and silty sand between 19.5
20
and 23 feet.
8�
76
23.0
Very stiff to hard, gray -brown, Silt (ML); moist;
trace of fine sand; low to medium plasticity
fines; iron -oxide staining; blocky texture.
25
Whidbey Formation (Qpnf)
9�
...........
65
........
CONTINUED NEXT SHEET o.20410
60
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-2
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-3
Geotechnical and Environmental Consultants Sheet 1 of 2
86
REV 3 - Approved for Submittal
Total Depth: 41.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 12 in.
Top Elevation: 129.0 ft. Longitude: oDrilling Company: Cascade Drilling Rod Diam.: 8.75-in.
Vert. Datum: Station: Drill Rig Equipment: CME 75 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o i
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 60
10
33.0
Hard, gray, Silt (ML); moist; trace of fine sand;
low plasticity fines; abundant iron -oxide
staining.
35
Whidbey Formation (Qpnl)
,2I
40
41.5
BOTTOM OF BORING
COMPLETED 11/21/2016
45
50
55
0 20 40 60
LEGEND
* Sample Not Recovered O % Fines (<0.075mm)
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-2
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-3
Geotechnical and Environmental Consultants Sheet 2 of 2
REV 3 - Approved for Submittal
Total Depth: 61.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 12 in.
Top Elevation: 129.0 ft. Longitude: oDrilling Company: Cascade Drilling Rod Diam.: 8.75-in.
Vert. Datum: Station: Drill Rig Equipment: CME 75 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 lbs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
3 inches of Asphalt.
0.3
0.4
2 inches of Road Base.
Medium dense, brown, Silty Sand (SM); moist;
trace fine gravel; primarily fine sand; trace
:10,
medium to coarse sand; nonplastic fines;%.
pocket of silt; trace burnt organics.
5
*:
:: ... '
'
Fill (Hf)
.;
2�
7.0
:.
3�
0 :::
Loose to medium dense, reddish -brown, Silty
Sand with Gravel (SM); moist; fine to coarse
gravel; primarily fine sand; trace medium to
coarse sand; nonplastic fines; scattered roots.
10
Fill (Hf)
•
., 4�
12.0
Medium dense, reddish -brown, Sand Silt
(ML); moist; fine sand; nonplastic fines; thin
5�
layers of sandy silt; iron -oxide staining.
Whidbey Formation (Qpnl)
15
6I
17.0
7�
Medium dense, gray -brown, Silt (ML); trace
fine sand; nonplastic fines; iron -oxide staining;
blocky texture; silty, fine sand interbeds.
Whidbey Formation (Qpnl)
19.5
8�
20
Medium dense, gray -brown, Silty Sand (SM);
moist; fine sand; nonplastic fines.
Whidbey Formation (Qpnl)
23.0
''
Dense to hard, gray -brown, Silt (ML); moist;
trace to few fine sand; nonplastic to low
plasticity; blocky texture.
25
Whidbey Formation (Qpnl)
s
CONTINUED NEXT SHEET 0....... 0.........4o........60
LEGEND
0 % Fines (<0.075mm)
* Sample Not Recovered
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-3
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-4
Geotechnical and Environmental Consultants Sheet 1 of 3
REV 3 - Approved for Submittal
Total Depth: 61.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 12 in.
Top Elevation: 129.0 ft. Longitude: oDrilling Company: Cascade Drilling Rod Diam.: 8.75-in.
Vert. Datum: Station: Drill Rig Equipment: CME 75 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 lbs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
(n
(j
between material types, and the transition may be gradual.
0 40 60
10T
. . . .
. .
11�
35
,2....
40
N
45
....
.....
13�
64
50
14�
5014:
15�-
55
Am
Grades to dark gray at 56 feet.
57.0
Dense, gray -brown, Silty Sand (SM); moist;
fine sand; iron -oxide staining.
Whidbey Formation (Qpnf)
CONTINUED NEXT SHEET Q 20 40 60
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-3
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-4
Geotechnical and Environmental Consultants Sheet 2 of 3
REV 3 - Approved for Submittal
Total Depth: 61.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 12 in.
Top Elevation: 129.0 ft. Longitude: oDrilling Company: Cascade Drilling Rod Diam.: 8.75-in.
Vert. Datum: Station: Drill Rig Equipment: CME 75 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 lbs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
16
61.5
BOTTOM OF BORING
COMPLETED 11/22/2016
65
70
75
80
85
0 20 40 60
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-3
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-4
ft
Geotechnical and Environmental Consultants Sheet ft
3
REV 3 - Approved for Submittal
Total Depth: 61.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 12 in.
Top Elevation: 119.0 ft. Longitude: oDrilling Company: Cascade Drilling Rod Diam.: 8.75-in.
Vert. Datum: Station: Drill Rig Equipment: CME 75 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
3 inches of Asphalt.
0.3
0.4
:
2 inches of Road Base.
Loose, reddish -brown, Poorly Graded Sand
with Silt (SP-SM) to Silty Sand (SM); moist;
trace gravel; primarily fine sand; trace organics
and wood.
5
Fill (Hf)
.;
2�
7.0
3�
Medium dense, brown, Silty Sand (SM); moist;
fine sand; silt layers/pockets.
Whidbey Formation (Qpnf)
9.5
10
Very stiff, gray -brown, Silt (ML); moist; trace
fine sand; low plasticity fines; iron -oxide
4�
staining.
Whidbey Formation (Qpnf)
12.0
a
I
`..
Medium dense, gray -brown, Silty Sand (SM) to
Poorly Graded Sand with Silt (SP-SM); moist;
fine sand; nonplastic fines; interbedded with
15
silt between 14.5 and 17 feet.
s�
Whidbey Formation (Qpnf)
19.5
81
20
Medium dense, gray -brown, Silty Sand (SM);
fine sand; iron -oxide staining.
Whidbey Formation (Qpnf)
X.
25.0
''
sI
25
Dense, reddish -brown, Silt (ML); moist; trace
::* :::
fine sand; nonplastic fines; iron -oxide staining.
25.5
Whidbey Formation (Qpnf)
Dense, gray -brown, Silty Sand (SM); moist;
fine sand.
.............................
..................
..........
Whidbey Formation (Qpnf)
.............................
...............
CONTINUED NEXT SHEET o.2 40
60
LEGEND
0 % Fines (<0.075mm)
* Sample Not Recovered
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-4
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-5
Geotechnical and Environmental Consultants Sheet 1 of 3
REV 3 - Approved for Submittal
Total Depth: 61.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 12 in.
Top Elevation: 119.0 ft. Longitude: oDrilling Company: Cascade Drilling Rod Diam.: 8.75-in.
Vert. Datum: Station: Drill Rig Equipment: CME 75 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 lbs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 2& 40 60
Dense to hard, gray -brown, Silt with Sand
(ML); moist; fine sand; nonplastic to low
io
plasticity fines; iron -oxide staining.
Whidbey Formation (Qpnf)
11�
35
38.0
Dense to very dense, gray, Silty Sand (SM) to
Poorly Graded Sand with Silt (SP-SM); moist;
fine sand; nonplastic fines.
40
Whidbey Formation (Qpnf)
12X.
45
13X.
50
x.•
14�
: 62
52.0
Very dense, brown, Silt (ML); moist; trace fine
sand; nonplastic fines; iron -oxide staining.
Whidbey Formation (Qpnf)
55
•
15�
........
60
........
CONTINUED NEXT SHEET o.2040
60
LEGEND
* Sample Not Recovered O % Fines (<0.075mm)
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-4
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-5
Geotechnical and Environmental Consultants Sheet 2 of 3
REV 3 - Approved for Submittal
Total Depth: 61.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 12 in.
Top Elevation: 119.0 ft. Longitude: oDrilling Company: Cascade Drilling Rod Diam.: 8.75-in.
Vert. Datum: Station: Drill Rig Equipment: CME 75 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 lbs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
16T
50V
61.5
BOTTOM OF BORING
COMPLETED 11/22/2016
65
70
75
80
85
0 20 40 60
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-4
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-5
Geotechnical and Environmental Consultants Sheet 3 of 3
REV 3 - Approved for Submittal
Total Depth: 41.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 12 in.
Top Elevation: 94.0 ft. Longitude: oDrilling Company: Cascade Drilling Rod Diam.: 8.75-in.
Vert. Datum: Station: Drill Rig Equipment: CME 75 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 lbs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
3-inch Asphalt. T0.3
0.4
2-inch Road Base.
Medium dense, brown, Silty Sand (SM); moist;
fine sand; iron -oxide staining.
�
Whidbey Formation (Qpnf)
5:
:•
2
I
7.0
Medium dense, brown, Silty Sand (SM)
interbedded with Silt (ML); moist; fine sand;
8.5
3�
nonelastic fines.
Whidbey Formation (Qpnf)J
9.5
41
10
Medium dense, gray -brown, Poorly Graded
Sand with Silt (SP-SM); moist; fine sand; siltX.
pockets.
Whidbey Formation (Qpnf)
5�
Loose to dense, gray -brown, Silty Sand (SM);
moist; fine sand; nonplastic fines interbedded
15.0
15
with layers of fine sandy silt.
5�
Whidbey Formation (Qpnf)
17.0
*:
Dense, gray -brown, Poorly Graded Sand with
Silt (SP-SM); moist; fine sand.
7�
Whidbey Formation (Qpnf)
19.5
'
20
Medium dense, gray -brown, Silty Sand (SM)
interbedded with Silt (ML); moist; fine sand;
8
nonplastic fines.
Whidbey Formation (Qpnf)
X.
Dense to very dense, gray -brown, Silty Sand
(SM); moist; fine sand; iron -oxide staining.
Whidbey Formation (Qpnf)
25
�•
9I
..
...............
.40
CONTINUED NEXT SHEET 0.20.
60
LEGEND
0 % Fines (<0.075mm)
* Sample Not Recovered
I 2.0" O.D. Split Spoon Sample % Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-5
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A.6
Geotechnical and Environmental Consultants Sheet 1 of 2
REV 3 - Approved for Submittal
Total Depth: 41.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 12 in.
Top Elevation: 94.0 ft. Longitude: oDrilling Company: Cascade Drilling Rod Diam.: 8.75-in.
Vert. Datum: Station: Drill Rig Equipment: CME 75 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 lbs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 Ak20 40 60
,0
63
33.0
'
Very dense, gray -brown, Silt (ML); moist; trace
fine sand; nonplastic fines; iron -oxide staining.
Whidbey Formation (Qpnl)
35
„I
37.0
Very dense, brown, Silty Sand (SM); moist;
fine sand; interbeds of fine sandy silt;
nonplastic fines.
Whidbey Formation (Qpnf)
40
12�
41.5
BOTTOM OF BORING
COMPLETED 11/23/2016
45
50
55
0 20 40 60
LEGEND
* Sample Not Recovered O % Fines (<0.075mm)
I 2.0" O.D. Split Spoon Sample % Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-5
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-6
Geotechnical and Environmental Consultants Sheet 2 of 2
82
REV 3 - Approved for Submittal
Total Depth: 130.8 ft. Latitude: oDrilling Method: Mud Rotary Hole Diam.: 5 in.
Top Elevation: 13.0 ft. Longitude: oDrilling Company: Holt Services, Inc. Rod Diam.: NWJ 2-5/8
Vert. Datum: Station: Drill Rig Equipment: Mobile Drill B57 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o i
lines indicated below represent the approximate boundaries
(
(j
between material types, and the transition may be gradual.
0 20 40 60
Asphalt and subgrade gravel.
(Fill)
1.0
Soft, dark brown, Silt (ML) and Organic Silt
(OL); moist to wet; few fine sand; little
3.0
75.0
.
organics.
Alluvium (Ha)/Colluvium (Hc)
::
2
5
Very loose, gray, Silty Sand (SM); moist;
mostly fine sand; little wood and organics.
m
Alluvium (Ha)/Colluvium (Hc)
31
o
Very loose, dark gray -brown, Poorly Graded
Sand with Silt and Gravel (SP-SM); moist to
wet; subrounded gravel; fine to coarse sand,
9.5
10
mostfine sand; few wood and organics.
4
Alluvium (Ha)/Colluvium (Hc)
- Wood fragments in cuttings from about 7 to
7.5 feet.
5
Medium dense, gray, Poorly Graded Sand with
Silt and Gravel (SP-SM); wet; fine to coarse,
15
subrounded gravel; fine to course sand; trace
6�
to few wood and organics.
Alluvium (Ha)/Colluvium (Hc)
19.0
'
Medium dense to dense, gray, Poorly Graded
Sand with Silt and Gravel (SP-SM); wet; fine to
20
coarse gravel and sand; low plasticity fines;
$
few interbeds of fine, silty sand; slight diamict
texture around 21 and 26 feet; few organics
and wood.
Alluvium (Ha)/Colluvium (Hc)
25
- Blow counts in this layer may be artificially
high due to presence of gravel.
28.0
0
0
........................
.40
CONTINUED NEXT SHEET O 20
60
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered a Ground Water Level ATD
% Water Content
I 2.0" O.D. Split Spoon Sample
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-6
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A.7
Geotechnical and Environmental Consultants Sheet 1 of 5
REV 3 - Approved for Submittal
Total Depth: 130.8 ft. Latitude: oDrilling Method: Mud Rotary Hole Diam.: 5 in.
Top Elevation: 13.0 ft. Longitude: oDrilling Company: Holt Services, Inc. Rod Diam.: NWJ 2-5/8
Vert. Datum: Station: Drill Rig Equipment: Mobile Drill B57 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
Medium dense to very dense, gray, Poorly
Graded Gravel with Silt and Sand (GP -GM);
0
10
wet; fine to coarse gravel and sand; low
0
11
plasticity fines; few brown organics; few
0
cobbles below 34 feet based on drill action.
o
Alluvium (Ha)/Colluvium (Hc)
0
35
- Few organics at about 35.5 feet.
12I
62
- Blow counts in this layer may be artificially
0
o
high due to presence of gravel.
38.0
Medium dense, gray, Poorly Graded Sand with
Silt and Gravel (SP-SM); moist to wet; few fine
40
gravel; fine to coarse sand; low plasticity fines;'
1. 13�
few organics; few 3-inch interbedded
blue -gray, gravelly silt and silty sand with low
to medium plasticity fines.
Alluvium (Ha)/Colluvium (Hc)
45
'
- 14Y.
50.0
''
50
Very dense, gray, Silty Sand (SM); wet; fine to
15�
67
medium sand; nonplastic to low plasticity fines;
few fine organics and silt partings to 56.5 feet.
Whidbey Formation (Qpnf)
:.
55
X.
16�
€ 2
CONTINUED NEXT SHEET 0 40 60
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered a Ground Water Level ATD
% Water Content
I 2.0" O.D. Split Spoon Sample
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-6
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-7
Geotechnical and Environmental Consultants Sheet 2 of 5
REV 3 - Approved for Submittal
Total Depth: 130.8 ft. Latitude: oDrilling Method: Mud Rotary Hole Diam.: 5 in.
Top Elevation: 13.0 ft. Longitude: oDrilling Company: Holt Services, Inc. Rod Diam.: NWJ 2-5/8
Vert. Datum: Station: Drill Rig Equipment: Mobile Drill B57 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
(n
0between
material types, and the transition may be gradual.
0 120 40 60
n
77
X.
65
X.
18�
7
70
::
19�
€ 1
75.0
::.
75
Medium dense, gray, Poorly Graded Sand with
20�A7:.Z.:
Silt (SP-SM); wet; few fine gravel; fine to
coarse sand; trace fines.
Whidbey Formation (Qpnf)
78.0
Very dense, gray, Poorly Graded Sand with
Silt (SP-SM); wet; fine to medium sand, mostly
fine sand; low plasticity to nonplastic fines.
80
'
X..
21
7fi
Whidbey Formation (Qpnf)
85
::
Y.
22I
:: 50/6
CONTINUED NEXT SHEET 0 2040 60
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered a Ground Water Level ATD
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-6
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-7
Geotechnical and Environmental Consultants Sheet 3 of 5
REV 3 - Approved for Submittal
Total Depth: 130.8 ft. Latitude: oDrilling Method: Mud Rotary Hole Diam.: 5 in.
Top Elevation: 13.0 ft. Longitude: oDrilling Company: Holt Services, Inc. Rod Diam.: NWJ 2-5/8
Vert. Datum: Station: Drill Rig Equipment: Mobile Drill B57 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
90.8
2s"`
JOF
70
Very dense, gray, Sandy Silt (ML); moist; fine
sand; nonplastic fines; few silt partings; 1/8- to
1/4-inch fine sand interbeds.
93.0
Whidbey Formation (Qpnl)
Very dense, gray, Silty Sand (SM); moist to
wet; fine sand; nonplastic fines.
95
'
Whidbey Formation (Qpnf)
:. 84
100
25I
50/6
X.
105
26I
50/6
.27�
110
- Silt partings, trace organics, and slight
iron -oxide staining below 110.5 feet.
. 2s=
115
117.0
Very dense, gray, Silt with Sand (ML); moist;
fine sand; nonplastic to low plasticity fines; fine
sand laminations.
...............
CONTINUED NEXT SHEET o.20. 40
60
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered a Ground Water Level ATD
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-6
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-7
Geotechnical and Environmental Consultants Sheet 4 of 5
REV 3 - Approved for Submittal
Total Depth: 130.8 ft. Latitude: oDrilling Method: Mud Rotary Hole Diam.: 5 in.
Top Elevation: 13.0 ft. Longitude: oDrilling Company: Holt Services, Inc. Rod Diam.: NWJ 2-5/8
Vert. Datum: Station: Drill Rig Equipment: Mobile Drill B57 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
(n
0between
material types, and the transition may be gradual.
0 20 40 60
Whidbey Formation (Qpnl)
29
5014
30=
125
50/5
130.8
3
130
50/4:.5
BOTTOM OF BORING
COMPLETED 4/14/2017
135
140
145
0 20 40 60
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered a Ground Water Level ATD
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-6
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-7
Geotechnical and Environmental Consultants Sheet 5 of 5
REV 3 - Approved for Submittal
Total Depth: 120 ft. Latitude: oDrilling Method: HSA and Mud Rotary Hole Diam.: 6 in.
Top Elevation: 15.0 ft. Longitude: oDrilling Company: Holt Services, Inc. Rod Diam.: NWJ 2-5/8
Vert. Datum: Station: Drill Rig Equipment: Mobile Drill B57 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
Soft to loose, brown and gray, mixed Sandy
Silt (ML) and Poorly Graded Sand with Silt
(SP-SM); wet below 2 feet; few pockets and
layers of fine to coarse gravel and sand; low to
medium plasticity fines; trace roots, organics,
'I
m
and charcoal; trace metal and glass debris.
4.5
0
Fill (Hf)
2
5
Very loose to very soft, gray to gray -brown,
interbedded, Silt (ML) and Silty Sand (SM);
wet; 2- to 6-inch-thick sand interbeds with
trace fine gravel; fine to coarse sand;
3
nonplastic to low plasticity fines with trace to
few brown organics.
10
::::::
uvium (Ha)/Colluvium (Hc)
10.8
41
}Ioose,
silty sand interbedded from about9
L
feet.
5
�
�
Very soft, gray to gray -brown, Silt (ML) ; wet;
fine sand; low plasticity fines; trace organics.
.... ...
Auk
....... .
Alluvium (Ha)/Colluvium (Hc)
15.0
s
15
Medium dense, gray, Poorly Graded Sand with
Silt and Gravel (SP-SM); wet; fine to coarse
gravel and sand; low plasticity fines.
Alluvium (Ha)/Colluvium (Hc)
X.,'
'I
- Intermittent gravel layers below 18.5 feet.
20
24.0
Very stiff, gray and green -gray, Silt with Sand
(ML); wet; few fine to coarse gravel and sand;
25
low plasticity fines; slight diamict texture; few
26.0
sI
1/4-inch-thick sand interbeds; trace organics.
Alluvium (Ha)/Colluvium (Hc)
28.0
Medium dense, gray, Silty Sand (SM); wet;
o
fine sand; low plasticity fines.
o
...............
CONTINUED NEXT SHEET 20 40.60
O
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered a Ground Water Level ATD
% Water Content
I 2.0" O.D. Split Spoon Sample
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-7
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
FSHANNON & WILSON, INC. FIG. A-8
Geotechnical and Environmental Consultants Sheet 1 of 5
REV 3 - Approved for Submittal
Total Depth: 120 ft. Latitude: oDrilling Method: HSA and Mud Rotary Hole Diam.: 6 in.
Top Elevation: 15.0 ft. Longitude: oDrilling Company: Holt Services, Inc. Rod Diam.: NWJ 2-5/8
Vert. Datum: Station: Drill Rig Equipment: Mobile Drill B57 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
Alluvium (Ha)/Colluvium (Hc)
°
10
Medium dense, gray, Poorly Graded Gravel
with Sand (GP); wet; fine to coarse gravel and
o
sand; low plasticity fines; trace organics.
°
Alluvium (Ha)/Colluvium (Hc)
O
°
Q
11�-
35
1-inch-long, brown, organic seam at about
°
36 feet.
37.0
Y.
Medium dense to very dense, gray, Poorly
Graded Sand with Silt and Gravel (SP-SM) to
Poorly Graded Gravel with Silt and Sand
40
(GP -GM); wet; fine to coarse gravel and sand;
:.,
12�
few pockets of low plasticity fines; sand with
intermittent layers of gravel.
Alluvium (Ha)/Colluvium (Hc)
- 6-inch-thick sand interbed at about 45 feet.
'
45
•
13X.
50
14=*
:: 100/6
- Fine, silty sand interbedded with trace
55
organics at about 56 feet.
- Blow counts in this layer may be artificially
high due to presence of gravel.
58.0
'
Medium dense to very dense, gray,
Well -Graded Gravel with Silt and Sand
.................
0.
CONTINUED NEXT SHEET O.. 2040
0
6
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered a Ground Water Level ATD
% Water Content
I 2.0" O.D. Split Spoon Sample
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-7
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-8
Geotechnical and Environmental Consultants Sheet 2 of 5
REV 3 - Approved for Submittal
Total Depth: 120 ft. Latitude: oDrilling Method: HSA and Mud Rotary Hole Diam.: 6 in.
Top Elevation: 15.0 ft. Longitude: oDrilling Company: Holt Services, Inc. Rod Diam.: NWJ 2-5/8
Vert. Datum: Station: Drill Rig Equipment: Mobile Drill B57 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
(GW-GM); wet; fine to coarse gravel and sand;
16
50/6
low plasticity fines; diamict texture.
Alluvium (Ha)/Colluvium (Hc)
'
.
,7I*
65
- 6-inch-thick fine, silty sand interbedded at
.........
....... ...........
about 66 feet.
.........
.........
.........
.........
...................
......... .........
...................
...................
•
181
70
.........
......... .........
- Boulder drilled through from about 72 to 77
.........
.........
.........
feet.
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
'
75
.........
.........
.........
.........
.........
.........
- Blow counts in this layer may be artificially
.........
.........
.........
high due to presence of gravel.
77.0
'
Very dense, gray, Silty Sand (SM); wet; fine to
medium sand; low plasticity fines; silt partings;
trace fine organics below 110 feet.
X..80
91
Whidbey Formation (Qpnf)
.,
19�
85
:.:
X.
.,.
20�
................
92
CONTINUED NEXT SHEET 0 20 4060
LEGEND
* Sample Not Recovered a Ground Water Level ATD O % Fines (<0.075mm)
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-7
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-8
Geotechnical and Environmental Consultants Sheet 3 of 5
REV 3 - Approved for Submittal
Total Depth: 120 ft. Latitude: oDrilling Method: HSA and Mud Rotary Hole Diam.: 6 in.
Top Elevation: 15.0 ft. Longitude: oDrilling Company: Holt Services, Inc. Rod Diam.: NWJ 2-5/8
Vert. Datum: Station: Drill Rig Equipment: Mobile Drill B57 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
U7
(n
0between
material types, and the transition may be gradual.
0 20 40 60
21T
90
95
22�
91.
100
All
'. 23�
7$
105
50/6
X.
2a=
110
50/4
- Boring drilled to 120 feet, but sampled to
Y.
2s=
115
50/6
115 feet.
CONTINUED NEXT SHEET 0 20.........4o........60
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered a Ground Water Level ATD
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-7
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-8
Geotechnical and Environmental Consultants Sheet 4 of 5
REV 3 - Approved for Submittal
Total Depth: 120 ft. Latitude: oDrilling Method: HSA and Mud Rotary Hole Diam.: 6 in.
Top Elevation: 15.0 ft. Longitude: oDrilling Company: Holt Services, Inc. Rod Diam.: NWJ 2-5/8
Vert. Datum: Station: Drill Rig Equipment: Mobile Drill B57 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
U7
(n
0between
material types, and the transition may be gradual.
0 20 40 60
BOTTOM OF BORING
COMPLETED 4/21/2017
125
130
135
140
145
0 20 40 60
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered a Ground Water Level ATD
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-7
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-8
Geotechnical and Environmental Consultants Sheet 5 of 5
REV 3 - Approved for Submittal
Total Depth: 26.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 4 in.
Top Elevation: 24.0 ft. Longitude: oDrilling Company: Holt Services, Inc. Rod Diam.: NWJ 2-5/8
Vert. Datum: Station: Drill Rig Equipment: Mobile Drill B57 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
- Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
Gray, angular trail Gravel (GP).
Fill (Hf)
1.0
Very loose, brown, Silty Sand (SM); moist; wet
below 5 feet; few fine gravel; fine to medium
sand; low plasticity fines; few organics and
wood; iron -oxide staining.
Alluvium (Ha)
:.
5
m
2
- 2-inch thick, gray, poorly graded sand layer
at about 6 feet.
7.0
31
o
Soft to stiff, gray to green -gray, Lean Clay with
Sand (CL); moist to wet; little fine gravel; fine
to coarse sand; low plasticity fines;
10
interbedded sand; trace pockets of medium
41
plasticity fines; few organics and wood;
iron -oxide staining; diamict texture.
Alluvium (Ha)/Colluvium (Hc)�::::
5
15.3
15
.......
.
Medium dense, gray, Silty Sand (SM); wet; few
6�
e gravel;fine to medium sand; low plasticity
16.5
es; few brown organics; slight diamict
ture; iron -oxide staining below 16 feet.
L
7uvium
(Ha)/Colluvium (Hc)
20.0
1
120
Medium dense to dense, brown, Sandy Silt
(ML); moist; fine sand; nonplastic to low
s�
plasticity fines; interbedded sand; iron -oxide
staining.
Colluvium (Hc)/Whidbey Formation (Qpnf)
24.0
.........
.........
.........
Medium dense to dense, gray -brown, Silty
Sand (SM); wet; fine to medium sand;
25
.........
....... .
.........
nonplastic fines.
91
Colluvium (Hc)/Whidbey Formation (Qpnf)
26.5
Dense to hard, gray and gray -green,
interbedded, Silty Clay (CL-ML) and Silty Sand
(SM); moist to wet; few fine gravel; fine to
........................
.40
CONTINUED NEXT SHEET O 20
60
LEGEND
O % Fines (<0.075mm)
* Sample Not Recovered a Ground Water Level ATD
% Water Content
I 2.0" O.D. Split Spoon Sample
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-8
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
FSHANNON & WILSON, INC. FIG. A-9
Geotechnical and Environmental Consultants Sheet 1 of 2
REV 3 - Approved for Submittal
Total Depth: 26.5 ft. Latitude: oDrilling Method: Hollow Stem Auger Hole Diam.: 4 in.
Top Elevation: 24.0 ft. Longitude: oDrilling Company: Holt Services, Inc. Rod Diam.: NWJ 2-5/8
Vert. Datum: Station: Drill Rig Equipment: Mobile Drill B57 Hammer Type: Automatic
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U
cr�
PENETRATION RESISTANCE (blows/foot)
Refer to the report text for a proper understanding of the
E
a
Z
A Hammer Wt. & Drop: 140 Ibs / 30 inches
subsurface materials and drilling methods. The stratification
Q
E
o i
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
coarse sand; low plasticity fines; slight diamict
texture; 3-inch thick sand layer at about 25.3
feet.
Iluvium (Ha)/Colluvium (Hc)
BOTTOM OF BORING
COMPLETED 4/21/2017
35
40
45
50
55
0 20 40 60
LEGEND
* Sample Not Recovered a Ground Water Level ATD O % Fines (<0.075mm)
I 2.0" O.D. Split Spoon Sample % Water Content
Plastic Limit 1 0 Liquid Limit
Natural Water Content
Meadowdale Beach
Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING MB-8
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-9
Geotechnical and Environmental Consultants Sheet 2 of 2
REV 3 - Approved for Submittal
Total Depth: 9.9 ft. Latitude: oDrilling Method: Hand Auger Hole Diam.: 4 in.
Top Elevation: 39.0 ft. Longitude: oDrilling Company: Shannon & Wilson Rod Diam.:
Vert. Datum: Station: Drill Rig Equipment: Hammer Type:
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U)
O % Fines (<0.075mm)
Refer to the report text for a proper understanding of the
E
a
a30
%Water Content
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
()
between material types, and the transition may be gradual.
0 20 40 60
Dark brown, Poorly Graded Gravel with Silt
G
.........
.........
.........
and Sand (GP -GM); moist; some fine to
0
2G
-
coarse sand; few nonplastic to low plasticity
m
fines; few organics; rounded to subangular.
1.3
3
'G
0
Fill (Hf)
- Wet below 0.8 foot.
2.0
eG
- 0 2
'
Gray and brown, Sandy Silt/Silty Sand
(ML/SM); moist to wet; low plasticity fines; few
rounded to subangular gravels; fine to medium
sG
sand.
4
Fill (Hf)
G
Brown, Silty Sand (SM); moist; trace rounded
to subrounded, fine gravel; fine to medium
sand; little nonplastic fines; trace organics.
5.5
_
n
Fill/Alluvium (Hf/Ha)
:
sG
6
M .
Gray -brown and gray, iron oxide -stained, Silty
Sand (SM); wet; trace rounded to subangular,
fine gravel; little to some nonplastic to low
plasticity fines; few clasts of gray, sandy silt;
.
s G
trace clasts of tan, blocky clay.
8
Alluvium/Colluvium (Ha/Hc)
10G
- Interlayered with gray, iron oxide -stained,
sandy silt below 9 feet.
9.9
10
BOTTOM OF BORING
COMPLETED 3/16/2017
12
14
0 20 40 60
LEGEND
* Sample Not Recovered Well Screen and Sand Filter
® Grab Sample ® Bentonite-Cement Grout
® Bentonite Chips/Pellets
® Bentonite Grout
a Ground Water Level ATD Meadowdale Beach
1 Ground Water Level in Well Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING HB— .1 1
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-10
Geotechnical and Environmental Consultants
REV 3 - Approved for Submittal
Total Depth: 6 ft. Latitude: oDrilling Method: Hand Auger Hole Diam.: 4 in.
Top Elevation: 30.0 ft. Longitude: oDrilling Company: Shannon & Wilson Rod Diam.:
Vert. Datum: Station: Drill Rig Equipment: Hammer Type:
Horiz. Datum: Offset: Other Comments:
SOIL DESCRIPTION
�
o
U)
O % Fines (<0.075mm)
Refer to the report text for a proper understanding of the
E
a
a30
%Water Content
subsurface materials and drilling methods. The stratification
Q
E
o a
lines indicated below represent the approximate boundaries
�
( j
between material types, and the transition may be gradual.
0 20 40 60
Grass at surface. Brown, Silty Gravel with
&
Sand and Cobbles (GM); wet; some angular
IG
- o
quarry spall cobbles; nonplastic fines.
1.0
Fill (Hf)
2.0
2G
o
2
Gray -brown and gray, Sandy Silt with Gravel
(ML); most; trace organics; low plasticity fines;
3 G
trace mica.
Fill (Hf)
3.0IF
4G
Gray -brown, Silty Sand with Gravel and
Cobbles (SM); moist; some rounded cobbles;
4
low plasticity fines; trace mica; fine to medium
5G
sand.
Fill (Hf)
s G
_
Brown, interlayered Silty Sand and Poorly
Graded Sand with Silt (SM/SP-SM); wet; trace
6.0
6
to few rounded to angular gravel; trace
organics; low plasticity fines; fine to medium
sand.
Fill/Alluvium (Hf/Ha)
- Iron -oxide -stained and with interlayered
$
sandy silt below 5 feet.
BOTTOM OF BORING
COMPLETED 3/16/2017
10
12
14
0 20 40 60
LEGEND
* Sample Not Recovered Well Screen and Sand Filter
® Grab Sample ® Bentonite-Cement Grout
® Bentonite Chips/Pellets
® Bentonite Grout
a Ground Water Level ATD Meadowdale Beach
1 Ground Water Level in Well Park and Estuary Restoration
NOTES Snohomish County, Washington
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING HB-2
4. The hole location was measured from existing site features and should be considered
approximate.
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. A-11
Geotechnical and Environmental Consultants
REV 3 - Approved for Submittal
SIii4MON&WI INC. JOB NO: 21-1-22288-040 DATE: 7/20/17 LOCATION: Meadowdale Beach Park
'�®IN C6L aNS ENYRiIpEML L'�ILTA NIi
LOG OF TEST PIT TP-1 PROJECT: Meadowdale Beach Park and Estuary Restoration
a
a? C:
N
LL
Sketch of East Pit Side Surface Elevation
SOIL DESCRIPTION
o m
Coc
0
CL
CL
Horizontal Distance in Feet
CU U)
m
0
0 2 4 6 8 10 12
p.......
.......
.......
..... ..
.........
Light brown, Silty Sand with Gravel
(SM); moist; little fine gravel; fine to
S-1
. . .
.
. . . . . . . . .
• • • • • • • •
. . . . . . . . .
• • • • •
. . . . . . .
• •
. . . . . .
• • • • • •
. . . . . . . . .
• • • • • • • • •
medium sand; low plasticity fines; few
.... .
Wood Fragment
.....O ..
.... ..
.. .....
........ .
Oorganics; scattered construction
. . . . . .
(Construction . .iris)..
. . . . . . .
. . . . . . . . .
. . . . .
debris; wood debris at 1.0 foot below
ground surface (b.g.s.). Concrete
S-2
2
oncrete Debris•
•
debris (8-inches in diameter) starting
\.
:
4
. . . . . . . .
. . . . . . .
at 2 feet b.g.s.
S-3
. . . . . . .
.........
. . . .
.. . ..
.... .
. .
........
...
.........
........ .
Holocene fill (Hf)
.
.�..
......
.........
.........
Dark brown, Poorly Graded Sand with
.........
.. . . ... .
.........
...... .
.........
........ .
Gravel (SP); moist; little fine to coarse
S-4
4
. . . . . . . . .
. . .
.
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
gravel; fine to medium sand; low
O plasticity fines; increasing frequency
. . . . . . . . .
. . . . . . . . .
. . . . . .
V
. . . . . . . . .
. . . . . . . .
of construction debris (wood
S-5
Concrete Slab
fragments, 6- to 9-inch diameter
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . .
concrete rubble). Encountered intact
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
concrete slab at 4.0 feet below
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . .
ground surface.
S-6
6
.........
.........
.........
.........
.........
.........
Holocene fill (Hf)
.. . . . . . . .
.........
.........
.........
. . . . . . . . .
.........
.........
.........
. . . . . . . . .
.........
.........
.........
. . . . . . . . .
.........
.........
.........
. . . . . . . . .
.........
.........
.........
. . . . . . . . .
.........
.........
.........
8
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
10
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
•
.........
.........
.........
.........
.........
.........
v.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
N.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
12
.........
.........
.........
.........
.........
.........
Photo 1: Test Pit TP-1 Location
Photo 3: TP-1 Sidewall Looking Southeast
SHANNON 6WILSON, INC.
Photo 2: TP-1 Sidewall Looking East
r
r'
Photo 4: TP-1 Backfilled
21-1-22288-060-R1 Test Pit excavation photos_TP-1/wp/ad 21-1-22288-060
SIii4MON&WI INC. JOB NO: 21-1-22288-040 DATE: 7/20/17 LOCATION: Meadowdale Beach Park
'�®IN C6L aNS ENYRiIpEML L'�ILTA NIi
LOG OF TEST PIT TP-2 PROJECT: Meadowdale Beach Park and Estuary Restoration
a
a? C:
N
LL
Sketch of East Pit Side Surface Elevation
SOIL DESCRIPTION
o m
Coc
0
CL
CL
Horizontal Distance in Feet
CU U)
m
0
0 2 4 6 8 10 12
0
...
.........
.........
Light brown, Silty Sand with Gravel
(SM); moist; little coarse to fine
. . . . . . .
. . . .
�1I I
.
. . . .
/.
gravel; fine to medium sand; low
. . . . . .
. . . . . .
?
•'
Oplasticity fines; abundent construction
. • .
.
.
.I .I .I .- .- .I .I .-
.. .. .. .. .. .. .. ..
. . . .
debris below 1.0 foot ground surface
. . . .
. . . . . . . . .
. . .
. . . . . .
. . . . . .
. . . . . . . . .
(b.g.s.), including wood fragments,
S-1
2
Wood Fragment
;s
Concrete
concrete rubble greater than 1-foot in
S-2
.. .....
(Construction Debris)
.
....with R
bar• • • • •
• • • • • • • • •
diameter with rebar, and metal debris.
Holocene fill (Hf)
S-3
... .....
••• •••
.........
.........
.........
.... ....
•••••
.........
......•••
•.
Debris •
. . ' ' Metal De
rig • • • •
• • • • • Concrete
• • • • •
• • • • • • • • •
Gray, Silty Sand with Gravel (SM);
..... ..
. ...
.....
.......
........ .
moist; wet below 5 feet; few organics;
S-4
4
' ' ' '
` '
' ' '
j.
. . .
. . . . . . . .
fine to coarse gravel; few
Olittle
2 cobbles; fine to medium sand;
8-5
' ' Flowing
increasing frequency of construction
. . . .
. . Groundw
te'r..O . . . .
. . . .
. . . . . . . . .
. . . . . . . . .
debris (wood, concrete rubble -
. . . . . .
' . . . . . . . .
. . . . . . . . .
. . . . . .
. . . . . . . .
3-inches to greater than 2-feet, and
. . . . . . . .
. . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . .
metal debris).
.. . . . . . . .
.........
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
Holocene fill (Hf)
6
.........
.........
.........
.........
.........
.........
.........
.........
......ConcrteSlab.....
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
8
.........
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.........
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.........
.........
.........
.........
.........
.........
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.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
10
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
•
.........
.........
.........
.........
.........
.........
v.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
w.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
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.........
12
.........
.........
.........
.........
.........
.........
Photo 1: Test Pit TP-2 Location
Photo 3: TP-2 Construction Debris
SHANNON 6WILSON, INC.
C
Photo 2: TP-2 Sidewall Looking Northeast
Photo 4: TP-2 Backfilled
21-1-22288-060-R1 Test Pit excavation photos_TP-2/wp/ad 21-1-22288-060
=. jj j3IWMN&W1L9[KINC JOB NO: 21-1-22288-040 DATE: 7/20/17 LOCATION: Meadowdale Beach Park
'�®1MOl A1Q EIWP�I4ElFT6L'�i1LTANli
LOG OF TEST PIT TP-3 PROJECT: Meadowdale Beach Park and Estuary Restoration
L
c
a
u-
Sketch of East Pit Side Surface Elevation
SOIL DESCRIPTION
o m
c: c
o
Q
E
Q
Horizontal Distance in Feet
CD
o v
CU
W
o
0 2 4 6 8 10 12
0
. .......
Light brown, Silty Sand with Gravel
....... ......... ......... . . . . .
(SM); moist; little coarse to fine
• • • • • • • • • • • • • • • • • • • • • • • • • ..
gravel; fine to medium sand; low
.... . . ......... doo Fragment
O plasticity fines; little construction
. . . . . . .
C
debris (wood, concrete rubble -
.
3-inches to greater than 2-feet in
S-1
2
diameter, and metal debris).
.. . ..... .. ........ .
Holocene fill (Hf)
Concrete .... ... .. ........
S-2
a Debris . . . . . e . . . . . . . . . . . . . . .
Gray, Silty Sand with Gravel (SM);
a ' ' ' ' . . . .
moist; wet below 5 feet; few organics;
• • • Flowing . • • • • •
little fine to coarse gravel; few
4
' ' ' Groundwater a' ' ' ' ' ' ' ' ' ' ' ' ' ' '
cobbles; fine to medium sand;
a . . . . . . . . .
O2 Increasing frequency of construction
a 4 . . . . .
.
debris (concrete debris 6-inches to
greater than 2-foot in diameter, wood
S-3
. . . . . . ° . . . . . . . . . . . . . . . . . .
. . . . . . ' ' 4 a
debris, and metal debris).
• • • • •°•
Holocene fill (Hf)
. . a Metal
6
Debris . ' ' '
S-4
••••••••• ......••• ••••••. Large Concrete Debris
......... ......... .......
8
......... ......... .........
......... ......... ........
10
D
12
SHANNON 6WILSON, INC.
Photo 1: Test Pit TP-3 Location Photo 2: TP-B Sidewall Looking Northeast
Photo 3: TP-3 Construction Debris
Photo 4: TP-3 Backfilled
21-1-22288-060-R1 Test Pit excavation photos_TP-3/wp/ad 21-1-22288-060
SHt4MON&WI INC. JOB NO: 21-1-22288-040 DATE: 7/20/17 LOCATION: Meadowdale Beach Park
'�®INC6L aNS ENYRiIpEMLL'�ILTANIi
LOG OF TEST PIT TP-B PROJECT: Meadowdale Beach Park and Estuary Restoration
a
a? C:
N
LL
Sketch of North Pit Side Surface Elevation
SOIL DESCRIPTION
3o m
Coc
0
CL
CL
Horizontal Distance in Feet
CU U)
m
0
0 2 4 6 8 10 12
0
.......
...
...
.........
......
Light brown, Silty Sand with Gravel
. . . . . . . .
. . . . . . . .
. . •
-Wood Fra
• .
(SM); moist; little coarse to fine
• • • • • • • •
• • • • • • • • •
. . . . . .
dn'D
:(Con'st:rucfi . .
br. . . . . . .
. . . . . .
gravel; fine to medium sand; low
. . . . . . . .D
......
. . . . . .
.
. . . . . . . .
.........
......
. .......
.......
plasticity fines; 1 foot below ground
.......•....
.. O: . .
. . .surface
(b.g.s.) some construction
. . . . . . . .....
. . . . .
. . . .
. . . . . . . . .
. . . . . . . .
. . . . . . . .
debris (wood, concrete rubble -
S-1
2
3-inches to greater than 2-feet in
. ......
.........
..... ..
. ...
�.....
........
........
diameter, and metal debris).
.....
..
.......
.........
Holocene fill (Hf)
S-2
.. .. •
. ...°..
• .. .
..
.... .
.. ..
... . . Cb
.........
c. I .Debris.
........
.........
Gray, Silty Sand with Gravel (SM);
.<:
. . . . . . . .
. . . . . . . . .
. . . . .
. . . .
. . . . . . . . .
moist; wet below 5 feet; few organics;
S-3
4
°
. . . . .
. . . . . . . . .
. . .
... . . . .
. . . .
. . . . . . . . .
little fine to coarse gravel; few
cobbles; fine to medium sand;
' ' ' ' '
' ' ' ' ' ' ' . .
. . n . .
..... . . .
. . .
O2 Increasing frequency of construction
. . . . .
. . . . . (9 . . .
..
. .
. . .
. . . . . .
. . . . . . . . .
debris (wood fragments, concrete
S-4
. . . • . . • •
• . • • . • • • •
. . a .
19 . .
. . . • .
rubble with and without rebar less
Fbiving
Groundwater
. . . . . . • • •
. . . . . . • • •
• • • • d. • • •
. . . . . . • • •
than 6-inches to greater than 1-foot in
. . . .
. . . . ' ' ' ' .
: : .
diameter, and metal debris).
6
°
a
Holocene fill (Hf)
' ' '
. . . . . .
tal;D; . o' ' '
' ' ' ' ' ' ' '
. .
' ' ' '
. . . . .
. . . . .
. . . . . . . . .
..... .
.........
......
. ...0..
.. ......
.........
8
�.
.......
.........
.......
.........
. . . . .
. . . . . .
. . . . . . a.
. . . . .
. ® ..
'. .. . . . . . . .
. . . . . . . . .
. . . . . . . .
. . . . . . .
. . . . . ..
. . . . . . . . .
. . . . . . . . .
.......
........
d
.....
.........
.......
.........
.........
...... ..
.........
.........
.........
.........
10
.........
.........
.........
.........
.......
.....
.........
.........
..... ...
.. .....
.........
.........
.........
.........
.....
.........
.........
:
.........
.........
.........
.........
.........
. . ..
.Concr
......
Slab . . . . .
.........
.........
v
.........
.........
.........
.........
....... . .
.........
.........
.........
.........
.........
.........
.........
U1
.........
.........
.........
.........
.........
.........
12
.........
.........
.........
.........
.........
.........
Photo 1: Test Pit TP-B Location
Photo 3: TP-B Construction Debris
SHANNON 6WILSON, INC.
J6
WWI
Photo 2: TP-B Sidewall Looking Northeast
MWINVINMA
Photo 4: TP-B Backfilled
�qr
21-1-22288-060-RI Test Pit excavation photos TP-B/wp/ad 21-1-22288-060
SHi4MON&WI INC. JOB NO: 21-1-22288-040 DATE: 7/20/17 LOCATION: Meadowdale
'�®IN C6L aNS ENYRiIpEML L'�ILTA NIi
LOG OF TEST PIT TP-RE-1 PROJECT: Meadowdale Beach Park
a
a? C:
(D
LL
Sketch of East Pit Side Surface Elevation
SOIL DESCRIPTION
3o m
Coc
0
CL
CL
Horizontal Distance in Feet
CU U)
m
0
0 2 4 6 8 10 12
0
.....Root.
........
Light brown, Silty Sand with Gravel
. . . . . .
. . . . . . . . .
1 . . . . . . . .
. . . . . ....
...... .
........ .
O(SM); moist; little fine gravel; fine to
1
S-1
• • • • •
.
• Root
medium sand; low plasticity fines; few
organics.
.......
.........
.........
.........
...
.........
Holocene fill (Hf)
. .... • ..
oot .......
.........
.........
. .....
........ .
S-2
2
2
Gray, Silty Sand with Gravel (SM);
. . . .
: Wood -Fragmen
moist; wet below 3 feet; little fine
. .
. . . . . . . . .
. . . . . . . . .
. . . . . . .
. . . . . . . .
. . . . . . . . .
O gravel; fine to medium sand; low
S-3
. . .
. . . . . . . . .
. . . . . . . .
plasticity fines; root fragments.
.
Holocene Alluvium (Ha)/Holocene
. . . •
:Flowing GroUhd
titer : • • • • •
. . . . . . •
. . . . . . • • •
. . . . . . • • •
Colluvium (Hc)
S-4
4
. . . . .
. . . . . .
. . . . . . . . .
. . . . . . . . .
Gray, Poorly Graded Sand (SP); wet;
.......
........
.
......
...... '.
.
.........
.........
O3 fine to medium sand.
S-5
........
. . . . . . . ...
. . . . . . .
. . . . ...
.........
........ .
Holocene Alluvium (Ha)/Holocene
. . . . . . . . .
' . . . . . . .
. . . . . . . . .
. . . . . .
. . . . . . . .
Colluvium (Hc)
. . . . . . . . .
.........
. . . . . .
.. ......
. . . . . . . . .
.........
. . . . . .
.. ......
. . . . . . . . .
.........
. . . . . . . . .
.........
S-6
6
.........
... .....
.........
. .......
.........
.........
.........
.........
.........
.........
........
.........
.........
.........
.
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
8
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
NOTES.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
.........
........
.........
.........
.........
.........
.........
.........
.........
.........
.........
1. T-probe penetration 3-6" at 1.0 foot
.........
......•••
......•••
......•••
......•••
......•••
......•••
below ground surface (b.g.s.)
.. . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
2. T-probe penetration 8-12" at 3.0
10
footb.g.s.
.........
.........
.........
.........
.........
.........
3. T-probe penetration >12" at 4.0 foot
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . .
.D b.g.s.
.........
.........
.........
.........
.........
.........
4.T-probe penetration > 12" at 5.0 foot
......•••
......•••
......•••
......•••
......•••
......•••
b.g.s.
........
.........
.........
.........
.........
.........
121
.........
.........
.........
.........
.........
.........
Photo 1: Test Pit TP-RE-1 Location
Photo 3: TP-RE-1 Sidewall Looking Northeast
SHANNON 6WILSON, INC.
Photo 2: TP-RE-1 Sidewall Looking East
Photo 4: TP-RE-1 Backfilled
21-1-22288-060-R1 Test Pit excavation photos_TP-RE-1/wp/ad 21-1-22288-060
SHANNON WALSON. INC.
APPENDIX B
GEOTECHNICAL LABORATORY TESTING
21-1-22288-060
SHANNON WALSON. INC.
APPENDIX B
GEOTECHNICAL LABORATORY TESTING
TABLE OF CONTENTS
Page
B.1
VISUAL CLASSIFICATION.........................................................................................B-1
B.2
WATER CONTENT DETERMINATION......................................................................B-1
B.3
GRAIN SIZE DISTRIBUTION ANALYSIS..................................................................B-1
B.3.1 Sieve Analysis...................................................................................................B-2
B.3.2 Fines Content Determination.............................................................................B-2
B.4
ATTERBERG LIMITS DETERMINATION..................................................................B-2
B.5
CONSIDERATIONS.......................................................................................................B-2
B.6
REFERENCES................................................................................................................B-3
Laboratory Terms
Sample Types
Laboratory Test Summary
TABLES
TESTS
Grain Size Distribution Plot, Boring MB-1
Grain Size Distribution Plot, Boring MB-2
Grain Size Distribution Plot, Boring MB-3
Grain Size Distribution Plot, Boring MB-4
Grain Size Distribution Plot, Boring MB-5
Grain Size Distribution Plot, Boring MB-6
Grain Size Distribution Plot, Boring MB-7
Grain Size Distribution Plot, Boring MB-8
Plasticity Chart, Boring MB-1
Plasticity Chart, Boring MB-2
Plasticity Chart, Boring MB-3
Plasticity Chart, Boring MB-4
Plasticity Chart, Boring MB-6
Plasticity Chart, Boring MB-7
21-1-22288-060-xi-ns 21-1-22288-060
B-i
TESTS (Continued)
Plasticity Chart, Boring MB-8
SHANNON WALSON. INC.
21-1-22288-060-xi-ns 21-1-22288-060
B-ii
SHANNON MMILSON, INC.
APPENDIX B
GEOTECHNICAL LABORATORY TESTING
We performed geotechnical laboratory testing on selected soil samples retrieved from eight of the
ten borings completed for the Meadowdale Beach Park and Estuary Restoration Project. The
laboratory testing program included tests to classify the soil and provide data for engineering
studies. We performed visual classification on all retrieved samples. Our laboratory testing
program included water content determinations, grain size distribution analyses, and Atterberg
limits determinations.
The following sections describe the laboratory test procedures.
B.1 VISUAL CLASSIFICATION
We visually classified soil samples retrieved from the borings using a system based on ASTM
International (ASTM) D2487-11, Standard Test Method for Classification of Soil for
Engineering Purposes, and ASTM D2488-09a, Standard Recommended Practice for Description
of Soils (Visual -Manual Procedure). We summarize our classification system in Appendix A.
We assigned a Unified Soil Classification System (USCS) group name and symbol, based on our
visual classification of particles finer than 76.2 millimeters (3 inches). We revised visual
classifications using results of the index tests discussed below.
B.2 WATER CONTENT DETERMINATION
We tested the water content of selected samples in accordance with ASTM D2216-10, Standard
Method for Laboratory Determination of Water (Moisture) Content of Soil, Rock, and Soil -
Aggregate Mixtures. Comparison of the water content of a soil with its index properties can be
useful in characterizing soil unit weight, consistency, compressibility, and strength. We present
water content test results in the Laboratory Test Summary table in this appendix, and graphically
on Appendix A exploration logs.
B.3 GRAIN SIZE DISTRIBUTION ANALYSIS
Grain size distribution analyses separate soil particles through mechanical or sedimentation
processes. Grain size distributions are used to classify the granular component of soils and can
correlate with soil properties, including frost susceptibility, permeability, shear strength,
liquefaction potential, capillary action, and sensitivity to moisture. We plot grain size
distribution analysis results in this appendix. Grain size distribution plots provide tabular
21-1-22288-060-R1-AB 21-1-22288-060
B-1
SHANNON MMILSON, INC.
information about each specimen, including: USCS group symbol and group name; water
content; constituent (i.e., cobble, gravel, sand, and fines) percentages; coefficients of uniformity
and curvature, if applicable; personnel initials; ASTM standard designation; and testing remarks.
Constituent percentages are presented in the Lab Summary Table in this appendix and fines
contents are plotted as data points on Appendix A exploration logs.
B.3.1 Sieve Analysis
We performed mechanical sieve analyses on selected soil specimens to determine the
grain size distribution of coarse -grained soil particles, in accordance with ASTM C136/C136M-
14, Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates.
B.3.2 Fines Content Determination
We determined the percent of fine-grained soil particles (fines content) of selected soil
specimens, in accordance with ASTM D1140-14, Standard Test Methods for Determining the
Amount of Material Finer Than 0.075 min (No. 200) Sieve in Soils by Washing.
BA ATTERBERG LIMITS DETERMINATION
We determined soil plasticity by performing Atterberg Limits tests on selected samples in
accordance with ASTM D4318-10e1, Standard Test Method for Liquid Limit, Plastic Limit, and
Plasticity Index of Soils, Method A (Multi -Point Liquid Limit). The Atterberg Limits include
liquid limit (LL), plastic limit (PL), and plasticity index (PI=LL-PL). These limits can assist soil
classification, indicate soil consistency (when compared to natural water content), provide
correlation to soil properties, evaluate clogging potential, and estimate liquefaction potential.
We present soil plasticity test results in the Lab Summary Table and on plasticity charts in this
appendix. Plasticity charts provide the liquid limit, plastic limit, plasticity index, USCS group
symbol, the sample description, water content, and percent passing the No. 200 sieve (if a grain
size distribution analysis was performed). Soil plasticity test results are also shown graphically
on Appendix A exploration logs.
B.5 CONSIDERATIONS
Drilling and sampling methodologies may affect the outcome of prescribed geotechnical
laboratory tests. Refer to the field exploration discussion in this report for a discussion of these
potential effects. Instances of limited recovery may have resulted in test samples not meeting
21-1-22288-060-R1-AB 21-1-22288-060
B-2
SHANNON WALSON. INC.
specified minimum mass requirements, per ASTM standards. Test plots show which samples do
not meet ASTM specified minimum mass requirements.
B.6 REFERENCES
ASTM International, 2011, Standard practice for classification of soils for engineering purposes
(unified soil classification system), D2487-11: West Conshohocken, Pa., ASTM
International, Annual book of standards, v. 04.08, soil and rock (I): D420 - D5876, 12 p.,
available: www.astm.org.
ASTM International, 2010, Standard test methods for laboratory determination of water
(moisture) content of soil and rock by mass, D2216-10: West Conshohocken, Pa., ASTM
International, Annual book of standards, v. 04.08, soil and rock (I): D420 - D5876, 7 p.,
available: www.astm.org.
ASTM International, 2014, Standard test method for sieve analysis of fine and coarse aggregates,
C136-14: West Conshohocken, Pa., ASTM International, Annual book of standards, v.
04.02, concrete and aggregates, 5 p., available: www.astm.org.
ASTM International, 2014, Standard test methods for determining the amount of material finer
than .075mm (no. 200) sieve in soils by washing, D1140-14: West Conshohocken, Pa.,
ASTM International, Annual book of standards, v. 04.08, soil and rock (I): D420 - D5876, 6
p., available: www.astm.org.
ASTM International, 2010, Standard test methods for liquid limit, plastic limit, and plasticity
index of soils, D4318-10el: West Conshohocken, Pa., ASTM International, Annual book of
standards, v. 04.08, soil and rock (I): D420 - D5876, 16 p., available: www.astm.org.
21-1-22288-060-xi-ns 21-1-22288-060
B-3
SHANNON WALSON. INC.
LABORATORY TERMS
Abbreviations,
Symbols, and Terms
Descriptions
°
Percent
*
Sample specimen weight did not meet required minimum mass for the test method
"
#
Inch
Test not performed by Shannon & Wilson, Inc. laboratory
ASTM Std.
ASTM International Standard
Cc
Coefficient of curvature
Clay -size
Soil particles finer than 0.002 min
cm
Centimeter
cm2
Square centimeter
Coarse -grained
Soil particles coarser than 0.075 min (cobble -,gravel- and sand -sized particles)
Cobbles
Soil particles finer than 305 min and coarser than 76.2 min
C„
Coefficient of uniformity
CU
Consolidated-Undrained
s
Axial strain
Fine-grained
Soil particles finer than 0.075 min (silt- and clay -sized particles)
ft
Feet
yin
Wet unit weight
Gravel
Soil particles finer than 76.2 min and coarser than 4.75 min
Gs
Specific gravity of soil solids
go
Initial height
4H
Change in height
OHioa.d
End of load increment deformation
in
Inch
in'
Cubic inch
LL
Liquid Limit
min
Minute
min
Millimeter
N, m
Micrometer
MC
Moisture content
MPa
Mega -Pascal
NP
Non -plastic
OC
Organic content
p
Total stress
p'
Effective stress
Pa
Pascal
pcf
Pounds per cubic foot
PI
Plasticity Index
PL
Plastic Limit
psf
Pounds per square foot
psi
Pounds per square inch
q
Deviatoric stress
Sand
Soil particles finer than 4.75 min and coarser than 0.075 min
sec
Second
Silt
Soil particles finer than 0.075 min and coarser than 0.002 min
t.
Time to n% primary consolidation
goad
Duration of load increment
tsf
Short tons per square foot
USCS
Unified Soil Classification System
UU
Unconsolidated-Undrained
WC
Water content
21-1-22288-060-R1-AB-Table 21-1-22288-060
SHANNON WALSON. INC.
SAMPLE TYPES
Abbreviations,
Symbols, and Terms
Descriptions
2SS
2.5-inch Outside Diameter Split -Spoon Sample
2ST
2-inch Outside Diameter Thin -Walled Tube
3HSA
3-inch CME Hollow -stem Auger Sampler
3SS
3-inch Outside Diameter Split -Spoon Sample
4SS
4-inch Inside Diameter Split -Spoon Sample
6SS
6-inch Inside Diameter Split -Spoon Sample
CA MC
Modified California Sampler
CA SPT
Standard Penetration Test (SPT)
CORE
Rock Core
DM
+3.25 inch Outside Diameter Split -Spoon Sample
DMR
3.25-inch Sampler with Internal Rings
GRAB
Grab Sample
GUS
3-inch Outside Diameter Gregory Undisturbed Sampler (GUS) Sample
OSTER
3-inch Outside Diameter Osterberg Sample
PITCHER
3-inch Outside Diameter Pitcher Sample
PMT
Pressuremeter Test f=failed
PO
Porter Penetration Test Sample
PT
2.5-inch Outside Diameter Thin -Walled Tube
ROCK
Rock Core Sample
SCORE
Soil Core (as in Sonic Core Borings)
SH 1
1-inch Plastic Sheath
SH2
2-inch Plastic Sheath with Soil Recovery
SH3
2-inch Plastic Sheath with no Soil Recovery
SPT
2-inch Outside Diameter Split -Spoon Sample
SS
Split -Spoon
ST
3-inch Outside Diameter Thin -Walled Tube
STW
3-inch Outside Diameter Thin -Walled Tube
TEST
Sample Test Interval
TW
Thin Wall Sample
UNDIST
Undisturbed Sample
VANE
Vane Shear
WATER
Water Sample for Probe Logs
XCORE
Core Sample
21-1-22288-060-R1-AB-Table 21-1-22288-060
SHANNON 6WILSON. INC.
LABORATORY TEST SUMMARY
Boring
s.
z
CA
V�
o
pa
USCS
WC (%)
o
0
o
C
C,
LL
PL
NP
Soil Description
MB-1
2
-1
SPT
MB-1
5
S-2
SPT
51
ML
7.8
33*
67*
Sandy Silt
MB-1
7.5
S-3
SPT
51
16.0
MB-1
10
S-4
SPT
52
26.1
MB-1
12.5
S-5
SPT
48
ML
27.2
30
25
Silt
MB-1
15
S-6
SPT
45
18.8
MB-1
17.5
S-7
SPT
48
14.1
MB-1
20
S-8
SPT
56
22.6
MB-1
25
S-9
SPT
63
ML
10.2
29*
71*
Silt with Sand
MB-1
30
5-10
SPT
65
16.4
MB-1
35
5-11
SPT
45
13.2
MB-1
40
5-12
SPT
47
16.8
MB-2
2.5
S-1
SPT
44
13.7
MB-2
5
S-2
SPT
31
ML
7.9
46
54
Sandy Silt
MB-2
7.5
S-3
SPT
26
4.3
MB-2
10
S-4
SPT
39
13.6
MB-2
12.5
S-5
SPT
38
4.8
MB-2
15
S-6
SPT
40
SM
5.8
75*
25*
Silty Sand
MB-2
17.5
S-7
SPT
81
ML
11.5
86
Silt
MB-2
20
S-8
SPT
76
9.8
MB-2
25
S-9
SPT
65
28.5
MB-2
30
5-10
SPT
22
ML
33.0
1
1
40
27
Silt
MB-2
35
5-11
SPT
41
24.7
MB-2
40
5-12
SPT
42
ML
26.6
35
26
Silt
MB-3
2.5
S-1
SPT
11
16.2
MB-3
5
S-2
SPT
18
19.3
MB-3
5.5
S-2
SPT
18
9.2
MB-3
7.5
S-3
SPT
6
SM
5.8
17
55
28
Silty Sand with Gravel
MB-3
10
S-4
SPT
24
4.8
MB-3
12.5
S-5
SPT
18
11.3
MB-3
15
S-6
SPT
23
ML
12.5
55
Sandy Silt
MB-3
1 17.5
S-7
SPT
1 19
20.0
21-1-22288-060-R1-AB-Table 21-1-22288-060
SHANNON 6WILSON. INC.
LABORATORY TEST SUMMARY
Boring
Q.
s.
z
E
CA
E
z
o
o
pa
USCS
WC (%)
o
0
w
o
C
C,
LL
PL
NP
Soil Description
M13-3
20
S-8
SPT
23
17.2
M13-3
25
S-9
SPT
38
13.0
M13-3
30
5-10
SPT
42
19.2
M13-3
35
5-11
SPT
36
ML
24.8
31
28
Silt
M13-3
40
5-12
SPT
42
30.6
M13-3
45
5-13
SPT
64
ML
29.0
33
25
Silt
M13-3
50
5-14
SPT
50/4"
27.2
M13-3
55
5-15
SPT
29
24.9
M13-3
55.5
5-15
SPT
29
25.0
M13-3
60
S-16
SPT
44
7.7
M13-4
2.5
S-1
SPT
14
8.9
M13-4
5
S-2
SPT
7
8.4
M13-4
7.5
S-3
SPT
25
12.3
M13-4
10
S-4
SPT
27
ML
24.2
29
23
Silt
M13-4
12.5
S-5
SPT
28
15.8
M13-4
15
S-6
SPT
27
21.1
M13-4
17.5
S-7
SPT
18
5.8
M13-4
20
S-8
SPT
25
SM
5.4
82*
18*
Silty Sand
M13-4
25
S-9
SPT
46
18.3
M13-4
25.5
S-9
SPT
46
9.6
M13-4
30
5-10
SPT
34
21.0
M13-4
35
5-11
SPT
51
ML
28.8
24
23
Silt with Sand
M13-4
40
5-12
SPT
51
14.2
M13-4
45
5-13
SPT
33
14.3
M13-4
50
5-14
SPT
62
4.9
M13-4
55
5-15
SPT
60
29.4
M13-4
60
5-16
SPT
50/6"
27.2
M13-5
2.5
S-1
SPT
19
SM
10.5
31
Silty Sand
M13-5
5
S-2
SPT
17
14.6
M13-5
7.5
S-3
SPT
15
16.7
M13-5
8
S-3
1
SPT
15
10.3
M13-5
1 10
S-4
SPT
1 5
16.8
21-1-22288-060-R1-AB-Table 21-1-22288-060
SHANNON 6WILSON. INC.
LABORATORY TEST SUMMARY
Boring
Q
s.
z
E
CA
E
z
o
o
pa
USCS
WC (%)
o
0
w
o
C
C,
LL
PL
NP
Soil Description
M13-5
12.5
S-5
SPT
42
15.0
M13-5
15
S-6
SPT
44
SP-SM
4.8
90
10
4.9
1.6
Poorly Graded Sand with Silt
M13-5
17.5
S-7
SPT
33
21.7
M13-5
20
S-8
SPT
46
16.6
M13-5
25
S-9
SPT
55
SM
7.3
83*
17*
Silty Sand
M13-5
30
5-10
SPT
63
10.2
M13-5
35
5-11
SPT
56
ML
22.6
82
Silt with Sand
M13-5
40
5-12
SPT
53
16.5
M13-6
3
S-1
SPT
2
34.9
M13-6
5
S-2
SPT
3
SP-SM
18.6
44
49
6.9
70.2
0.1
Poorly Graded Sand with Silt and Gravel
M13-6
10
S-4
SPT
19
12.5
M13-6
15
S-6
SPT
24
12.4
M13-6
17.5
S-7
SPT
23
SP-SM
6.5
33*
57*
9.7*
36.9
Poorly Graded Sand with Silt and Gravel
M13-6
20
S-8
SPT
45
8.2
M13-6
25
S-9A
SPT
35
SP-SM
10.1
31 *
59*
9.2*
35.9
0.7
Poorly Graded Sand with Silt and Gravel
M13-6
26.3
S-9
SPT
35
17.4
M13-6
35
5-12
SPT
62
GP -GM
8.2
49
42
8.5
84.7
0.6
Poorly Graded Gravel with Silt and Sand
M13-6
40
5-13
SPT
25
12.0
M13-6
40.3
5-13
SPT
25
17.2
M13-6
45
5-14
SPT
21
16.4
M13-6
50
5-15
SPT
67
23.7
M13-6
55
5-16
SPT
82
SP-SM
25.9
0*
88*
l l *
Poorly Graded Sand with Silt
M13-6
60
5-17
SPT
77
19.5
M13-6
65
5-18
SPT
70
22.2
M13-6
70
5-19
SPT
81
21.4
M13-6
75
5-20
SPT
23
SP-SM
25.3
1 *
93*
5.9*
2.2
0.8
Poorly Graded Sand with Silt
M13-6
80
5-21
SPT
76
22.8
M13-6
85
5-22
SPT
50/6
SP-SM
20.8
91 *
9.1 *
Poorly Graded Sand with Silt
M13-6
90
5-23
SPT
70
23.1
M13-6
90.8
S-23B
SPT
70
ML
24.4
26.18
27.95
NP
Silt
M13-6
95
5-24
SPT
84
24.6
M13-6
100
5-25
SPT
50/6
22.9
21-1-22288-060-R1-AB-Table 21-1-22288-060
SHANNON 6WILSON. INC.
LABORATORY TEST SUMMARY
Boring
Q
s.
z
E
E
o
o
USCS
WC (%)
o
0
w
o
C
C,
LL
PL
NP
Soil Description
M13-6
105
S-26
SPT
50/6
21.3
M13-6
110
5-27
SPT
5015
21.9
M13-6
115
5-28
SPT
5015.5
22.9
M13-6
120
5-29
SPT
50/4
23.4
M13-6
125
5-30
SPT
5015
22.7
M13-6
130
5-31
SPT
50/4.5
23.1
M13-7
2.5
S-1
SPT
4
29.6
M13-7
5
S-2
SPT
1
SM
29.8
Silty Sand
M13-7
7.5
S-3
SPT
9
29.3
M13-7
10
S-4
SPT
1
23.8
M13-7
10.8
S-413
SPT
1
ML
24.6
26.49
22.41
Silt
M13-7
12.5
S-5
SPT
1
30.9
M13-7
15
S-6
SPT
26
11.8
M13-7
17.5
S-7
SPT
29
SP-SM
12.2
35*
59*
5.5*
1.5
1.2
Poorly Graded Sand with Silt and Gravel
M13-7
20
S-8
SPT
22
17.9
M13-7
25
S-9A
SPT
18
ML
19.7
20.77
18.61
Silt with Sand
M13-7
26
S-9
SPT
18
15.8
M13-7
30
5-10
SPT
23
GP
8.7
51
45
3.6
30.8
0.9
Poorly Graded Gravel with Sand
M13-7
35
5-11
SPT
14
10.1
M13-7
40
5-12
SPT
39
SP-SM
9.1
39*
55*
6.3*
41.8
0.3
Poorly Graded Sand with Silt and Gravel
M13-7
45
5-13
SPT
32
34.9
M13-7
55
5-15
SPT
59
8.7
M13-7
56
5-15
SPT
59
20.8
M13-7
60
5-16
SPT
50/6
GW-GM
8.5
46
45
9.2
74.9
1.1
Well -Graded Gravel with Silt and Sand
M13-7
65
5-17
SPT
32
14.8
M13-7
70
5-18
SPT
52
7.7
M13-7
80
5-19
SPT
91
SM
20.4
88*
12*
Silty Sand
M13-7
85
5-20
SPT
92
21.3
M13-7
90
5-21
SPT
90
22.9
M13-7
95
5-22
SPT
91
20.7
M13-7
100
5-23
SPT
78
23.3
M13-7
105
5-24
SPT
50/6
21.7
21-1-22288-060-R1-AB-Table 21-1-22288-060
SHANNON 6WILSON. INC.
LABORATORY TEST SUMMARY
W
A
a
c.
U
se°•
�
Boring
H
CA
C.40
pa
USCS
WC (%)
e
o
o
C
C,
LL
PL
NP
Soil Description
-7
PT
50 4
235
MB-7
115
S-26
SPT
50/6
21.7
MB-8
5
S-2
SPT
1
SM
22.7
7*
71 *
21 *
Silty Sand
MB-8
7.5
S-3
SPT
9
19.8
MB-8
10
S-4
SPT
9
22.0
MB-8
12.5
S-5
SPT
3
CL
25.1
31.09
21.58
Lean Clay with Sand
MB-8
15
S-6
SPT
13
23.7
MB-8
15.3
S-6
SPT
13
22.3
MB-8
17.5
S-7
SPT
35
ML
18.4
50*
50*
Sandy Silt
MB-8
20
S-8
SPT
30
SM
21.8
79*
21 *
Silty Sand
MB-8
25
S-9A
SPT
38
1 CL-ML
22.7
1
1
129.39
22.29
Silty Clay
MB-8
25.3
S-9
SPT
38
1
17.1
21-1-22288-060-R1-AB-Table 21-1-22288-060
SHANNON &WILSON, INC. GRAIN SIZE DISTRIBUTION PLOT
Meadowdale Beach
Park and Estuary Restoration
Snohomish County, Washington
BORING MB-1
b d o 0
M ti ^ ^ b �o ryo bo 00 �o
0 00 ob o0 oti o a a a s Doti o0
ti� o• o• o• o' o• o• o• o• o• W o
100
95
0
5
90d
10
85
15
80
20
I
75
25
70
30
65
35
N
CD
60
40
co
CD
55
45 C7
O
Q 50
50 N
IL
N
45
55 Q
U
�
Q 40
60 N
d
q1
N
35
65
30
70
25
75
20
80
15
85
10
90
5
95
0
100
ry
�o
00 'O „O O ^O Q> '6 •n b ^J R. ^ 0 (8 b ^� �Y ^ ^`� 00
o-. o 0 0• o• o 0 0 0
0
Grain Size (mm)
O� O°j O� O 00 00
0 0 0 0 0 0 0 0 0° O
0 0 0 0 1W o'
ro
N
0
Test specimen did not meet minimum mass recommendations.
>J_
>I
Z
Q
a
0
v
0
°o
ao
N
N
N
N
Z
Q
Q
U
Q
0
0
0
00
00
N
N
N
N
Gravel
Sand
Fines
Coarse Fine
Coarse Medium Fine
Silt Clay -Size
Mesh Opening in Inches
Mesh Openings per Inch, U.S. Standard
Grain Size in Millimeters
Sample
Depth
USCS
USCS
Gravel
Sand
Fines
<20Um
<21um
WC
Tested
Review
ASTM
Identification
(ft)
Symbol
Group Name
%
%
%
%
%
%
By
By
Std.
OMB-1,S-2
5.0
ML
Sandy Silt
33
67
7.8
AI�V
JFL
C136
■MB-1, S-9
25.0
ML
Silt with Sand
29
71
10.2
Ai(V
JFL
C136
SHANNON & WILSON, INC. 400 NORTH 34TH STREET SUITE 100 SEATTLE, WASHINGTON 98103 MAIN (206) 632-8020 • FAX (206) 695-6777
SHANNON &WILSON, INC. GRAIN SIZE DISTRIBUTION PLOT
Meadowdale Beach
Park and Estuary Restoration
Snohomish County, Washington
BORING MB-2
M ti ^ ^ � � � b ^ ry a o ^
ti o' o' o' o' o' o' o' o' o' o• o'
100
0
95
5
90
10
85
15
80
20
75
25
70
30
65
35
V1
CD
Cl) 60
40
CD
4 55
Ilk-45
O
50
50 N
IL
N
45
55 Q
U
40
60
0_
y
N
35
65
30
70
25--75
20
80
15
85
10
90
5
95
0
100
n.
^•o'
00 a0 „O 10 ^O 0 0 ^b b °� R. ^ 0 0 b �i N ^ ^h 00
b. O' O' O' O' O' O' O O'
O'
Grain Size (mm)
Ob O°j Ory O 00 00 Ob O� Ory O^
O' O' O' O' O O O O O O
O' O' O' O' w O'
ro
N
0
c�
>J_
Z
Q
x
a
0
v
0
°o
N
N
N
N
Z
Q
Q
U
Q
0
0
0
00
0
N
N
N
N
Test specimen did not meet minimum mass recommendations.
Gravel
Sand
Fines
Coarse Fine
Coarse Medium Fine
Silt Clay -Size
Mesh Opening in Inches
Mesh Openings per Inch, U.S. Standard
Grain Size in Millimeters
Sample
Identification
Depth
(ft)
USCS
Symbol
USCS
Group Name
Gravel
%
Sand
%
Fines
%
< 20Nm
%
< 21um
%
WC
%
Tested
By
Review
By
ASTM
Std.
OMB-2,S-2
5.0
ML
Sandy Silt
46
54
7.9
AKV
JFL
C136
■MB-2, S-6
15.0
SM
Silty Sand
75
25
5.8
AKV
JFL
C136
♦MB-2, S-7
17.5
ML
Silt
86
11.5
AKV
JFL
D1140
SHANNON & WILSON, INC. 400 NORTH 34TH STREET •SUITE 100 SEATTLE, WASHINGTON 98103 •MAIN (206) 632-8020 •FAX (206) 695-6777
SHANNON &WILSON, INC. GRAIN SIZE DISTRIBUTION PLOT
L
0I
0
0
V
V
Meadowdale Beach
Park and Estuary Restoration BORING MB-3
Snohomish County, Washington
Gravel
Sand
Fines
Coarse I Fine
Coarse Medium Fine
Silt Clay -Size
Mesh Opening in Inches
Mesh Openings per Inch, U.S. Standard
Grain Size in Millimeters
O O 00 Op 00 Ory O 000 000 06 000 oory
drain 5tze (mm)
O
O
O'
0
5
10
15
20
25
30
35
CD
40 N
7
45 (7
O
50 N
(D
55 Q
60
N
N
65
70
75
80
85
90
95
100
Sample
Depth
USCS
Grou
USCS
Gravel
Sand
Fines
< 20Nm
< 21um
WC
Tested
Review
ASTM
Identification
(ft)
Symbol
Group Name
oD
%
%
%%
%
By
By
Std.
Ill S-3
7.5
SM
Silty Sand with Gravel
17
55
28
5.8
AKV
JFL
C136
■MB-3, S-6
15.0
ML
Sandy Silt
55
12.5
AKV
JFL
D1140
Test specimen did not meet minimum mass recommendations.
SHANNON & WILSON, INC. • 400 NORTH 34TH STREET • SUITE 100 • SEATTLE, WASHINGTON • 98103 • MAIN (206) 632-8020 • FAX (206) 695-6777
SHANNON &WILSON, INC. GRAIN SIZE DISTRIBUTION PLOT
Meadowdale Beach
Park and Estuary Restoration
Snohomish County, Washington
BORING MB-4
M ti ^ ^ � � � b ^ ry a o ^
ti o' o' o' o' o' o' o' o' o' o• o'
100
0
95
5
90
10
85
15
80
20
75
25
70
30
65
35
V1
CD
Cl)60
40
N
-0 55
45 C7
O
ai 50
50 N
IL
N
45
55 Q
U
�
40
60
0_
y
N
35
65
30
70
25
75
20
80
15
85
10
90
5
95
0
100
n.
00 po �o 7
O'
O'
Grain Size (mm)Grou
Ob O� Ory O 006 00 Ob O� Ory O^
O' O' O' O' O O O O O O
O' O' O' O' O' O'
N
Test specimen did not meet minimum mass recommendations.
0
c�
J_
31
Z
Q
2
a
O
0
a
0
ao
N
N
N
N
Z
Q
Q
QI
0
0
0
00
0
N
N
N
N
Gravel
Sand
Fines
Coarse Fine
Coarse Medium Fine
Silt Clay -Size
Mesh Opening in Inches
Mesh Openings per Inch, U.S. Standard
Grain Size in Millimeters
Sample
Depth
USCS
USCS
Gravel
Sand
Fines
< 20Nm
< 21um
WC
Tested
Review
ASTM
Identification
(fit)
Symbol
Group Name
%
%
%
%
%
%
By
By
Std.
OMB-4, S-8
20.0
SM
Silty Sand
82
18
5.4
AI(V
JFL
C136
SHANNON & WILSON, INC. 400 NORTH 34TH STREET SUITE 100 SEATTLE, WASHINGTON 98103 MAIN (206) 632-8020 • FAX (206) 695-6777
SHANNON &WILSON, INC. GRAIN SIZE DISTRIBUTION PLOT
Meadowdale Beach
Park and Estuary Restoration BORING MB-5
Snohomish County, Washington
M ti ^ ^ � � � b ^ ry a o ^ ti o' o' o' o' o' o' o' o' o' o• o'
100
0
95
5
90
10
85
15
80
20
75
25
70
30
65
35
V1
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N 60
40
N
4 55
45
O
50
50 N
I L
(D
C 45
55 Q
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N 40
60
0_
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N
35
65
30
70
25
75
20
80
15
85
10
90
5
95
0
100
n.
^O'
00 a0 „O 10 ^O 0 0 ^b b 6 R. ^ 0 0 b 16 N ^ ^h 00 Ob O°j Ory O 66 -1 Ob O1 Ory O^
b. O' O' O' O' O' O' O O O O O O
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0
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x
Test specimen did not meet minimum mass recommendations.
a
0
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N
N
N
N
Z
Q
Q
U
Q
0
0
0
00
0
N
N
N
N
Gravel
Sand
Fines
Coarse Fine
Coarse Medium Fine
Silt Clay -Size
Mesh Opening in Inches
Mesh Openings per Inch, U.S. Standard
Grain Size in Millimeters
Sample
Identification
Depth
(ft)
USCS
Symbol
USCS
Group Name
Gravel
%
Sand
%
Fines
%
< 20Nm
%
< 21um
%
WC
%
Tested
By
Review
By
ASTM
Std.
OMB-5,S-1
2.5
SM
Silty Sand
31
10.5
AI(V
JFL
D1140
■MB-5, S-6
15.0
SP-SM
Poorly Graded Sand with Silt
90
10
4.8
AKV
JFL
C136
♦MB-5, S-9
25.0
SM
Silty Sand
83
17
7.3
AI(V
JFL
C136
♦MB-5, S-11
35.0
ML
Silt with Sand
82
22.6
AI(V
JFL
D1140
SHANNON & WILSON, INC. 400 NORTH 34TH STREET •SUITE 100 SEATTLE, WASHINGTON 98103 •MAIN (206) 632-8020 •FAX (206) 695-6777
SHANNON &WILSON, INC. GRAIN SIZE DISTRIBUTION PLOT
Meadowdale
RestorationPark and Estuary BORING B-6
Snohomish County, Washington
Gravel
Gravel
Sand
Fines
Coarse Fine
Coarse Medium Fine
Silt Clay -Size
Mesh Opening in Inches
Mesh Openings per Inch, U.S. Standard
Grain Size in Millimeters
Sample
Identification
Depth
(fit)
USCS
Symbol
USCS
Group Name
Gravel
%
Sand
%
Fines
%
< 20Nm
%
< 21um
%
WC
%
Tested
By
Review
By
ASTM
Std.
OMB-6, S-2
5.0
SP-SM
Poorly Graded Sand with Silt and Gravel
44
49
6.9
18.6
BMC
JFL
C136
■MB-6, S-7
17.5
SP-SM
Poorly Graded Sand with Silt and Gravel
33
57
9.7
6.5
BMC
JFL
C136
♦MB-6, S-9A
25.0
SP-SM
Poorly Graded Sand with Silt and Gravel
31
59
9.2
10.1
BMC
JFL
C136
40MB-6, 5-12
35.0
GP -GM
Poorly Graded Gravel with Silt and Sand
49
42
8.5
8.2
BMC
JFL
C136
OMB-6, S-16
55.0
SP-SM
Poorly Graded Sand with Silt
0
88
11
25.9
BMC
JFL
C136
❑MB-6, S-20
75.0
SP-SM
Poorly Graded Sand with Silt
1
93
5.9
25.3
BMC
JFL
C136
OMB-6, S-22
85.0
SP-SM
Poorly Graded Sand with Silt
91
9.1
20.8
BMC
JFL
C136
SHANNON & WILSON, INC. 400 NORTH 34TH STREET •SUITE 100 SEATTLE, WASHINGTON 98103 •MAIN (206) 632-8020 •FAX (206) 695-6777
SHANNON &WILSON, INC. GRAIN SIZE DISTRIBUTION PLOT
Meadowdale
RestorationPark and Estuary BORING B-7
Snohomish County, Washington
Gravel
Gravel
Sand
Fines
Coarse Fine
Coarse Medium Fine
Silt Clay -Size
Mesh Opening in Inches
Mesh Openings per Inch, U.S. Standard
Grain Size in Millimeters
Sample
Identification
Depth
(fit)
USCS
Symbol
USCS
Group Name
Gravel
%
Sand
%
Fines
%
< 20Nm
%
< 21um
%
WC
%
Tested
By
Review
By
ASTM
Std.
OMB-7, S-7
17.5
SP-SM
Poorly Graded Sand with Silt and Gravel
35
59
5.5
12.2
BMC
JFL
C136
■MB-7, S-10
30.0
GP
Poorly Graded Gravel with Sand
51
45
3.6
8.7
BMC
JFL
C136
♦MB-7, 5-12
40.0
SP-SM
Poorly Graded Sand with Silt and Gravel
39
55
6.3
9.1
BMC
JFL
C136
♦MB-7, 5-16
60.0
GW-GM
Well -Graded Gravel with Silt and Sand
46
45
9.2
8.5
BMC
JFL
C136
0MB-7, 5-19
80.0
SM
Silty Sand
88
12
20.4
BMC
JFL
C136
SHANNON & WILSON, INC. 400 NORTH 34TH STREET •SUITE 100 SEATTLE, WASHINGTON 98103 •MAIN (206) 632-8020 •FAX (206) 695-6777
SHANNON &WILSON, INC. GRAIN SIZE DISTRIBUTION PLOT
Meadowdale Beach
Park and Estuary Restoration
Snohomish County, Washington
BORING MB-8
M ti ^ ^ � � � a ^ ry a o ^
o°o o°° o°b o°o -R, o°
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90
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85
15
80
20
75
25
70
30
65
35
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40
CD
4 55
45
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50
50 N
IL
N
C 45
55 Q
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40
60
0.
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N
35
65
30
70
25
75
20
80
15
85
10
90
5
95
0
100
n.
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O' O' O' O' O' O'
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0
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aTest
x
a
0
v
0
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N
N
N
N
Z
Q
Q
U
Q
0
0
0
00
0
N
N
N
N
specimen did not meet minimum mass recommendations.
Gravel
Sand
Fines
Coarse Fine
Coarse Medium Fine
Silt Clay -Size
Mesh Opening in Inches
Mesh Openings per Inch, U.S. Standard
Grain Size in Millimeters
Sample
Identification
Depth
(ft)
USCS
Symbol
USCS
Group Name
Gravel
%
Sand
%
Fines
%
< 20Nm
%
< 21um
%
WC
%
Tested
By
Review
By
ASTM
Std.
OMB-8, S-2
5.0
SM
Silty Sand
7
71
21
22.7
BMC
JFL
C136
■MB-8, S-7
17.5
ML
Sandy Silt
50
50
18.4
BMC
JFL
C136
♦MB-8, S-8
20.0
SM
Silty Sand
79
21
21.8
BMC
JFL
C136
SHANNON & WILSON, INC. 400 NORTH 34TH STREET •SUITE 100 SEATTLE, WASHINGTON 98103 •MAIN (206) 632-8020 •FAX (206) 695-6777
SHANNON &WILSON, INC. PLASTICITY CHART
Meadowdale Beach
Park and Estuary Restoration
BORING MB-1
Snohomish County, Washington
�o
60
50
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FL
ao
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U
30
@
a
20
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10
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FIA-
04
0 10 20 30 40
50 60
70 80 90 100 110
Liquid Limit - LL
N
H
0
>J_
Q
I
a
c0
d
a
0
°o
00
N
N
N
N
Z
Q
FI
H
Q�
Q
0
0
0
00
0
N
N
N
N
Sample
Depth
GrouS
USCS
LL
PL
pl
WC
Gravel
Sand
Fines
<21um
Tested
Review
ASTM
Identification
(ft)
Symbol
Group Name
%
%
%
%
%
By
By
Std.
SHANNON & WILSON, INC. 400 NORTH 34TH STREET •SUITE 100 SEATTLE, WASHINGTON 98103 •MAIN (206) 632-8020 •FAX (206) 695-6777
SHANNON &WILSON, INC. PLASTICITY CHART
Meadowdale Beach
Park and Estuary Restoration
BORING MB-2
Snohomish County, Washington
70
50
50
/
FL
ao
x
a>
c
/
U
30
/
@
a
lo
zo
/
10
GIL
or
C111.
10
0
0 10 20 30
40
50
60
70
80 90 100 110
Liquid Limit
- ILLrou
N
0
>J_
ZI
Q
a
c0
0
It0
°o
ro
N
N
N
N
Z
Q
H
F
QI
a
0
0
0
00
0
N
N
N
N
Sample
Depth
USCS
USCS
WC
Gravel
Sand
Fines
<21um
Tested
Review
ASTM
Identification
(ft)
Symbol
Group Name
SHANNON & WILSON, INC. 400 NORTH 34TH STREET SUITE 100 SEATTLE, WASHINGTON 98103 MAIN (206) 632-8020 • FAX (206) 695-6777
SHANNON &WILSON, INC. PLASTICITY CHART
Meadowdale Beach
Park and Estuary Restoration
BORING MB-3
Snohomish County, Washington
70
60
50
FL
ao
x
a>
c
�
U
30
'
@
a
lo
loe
10
fag
•
0
0 10 20 30
40
50
60
70
80 90 100 110
Liquid Limit
- LL
ro
N
0
c7
>J_
Q
I
a
c0
cS
a
0
oo
oo
N
N
N
N
Z
Q
FI
H
Q�
Q
0
0
0
00
00
N
N
N
N
Sample
Depth
USCS
USCS
LL
PL
PI
WC
Gravel
Sand
Fines
<21um
Tested
Review
ASTM
Identification
(ft)
Symbol
Group Name
%
%
%
%
%
By
By
Std.
•MB-3, S-11
35.0
ML
Silt
31
28
3
24.8
AKV
JFL
D4318
FMB-3, S-13
45.0
ML
Silt
33
25
8
29.0
AKV
JFL
D4318
SHANNON & WILSON, INC. 400 NORTH 34TH STREET •SUITE 100 SEATTLE, WASHINGTON 98103 •MAIN (206) 632-8020 •FAX (206) 695-6777
SHANNON &WILSON, INC. PLASTICITY CHART
Meadowdale Beach
Park and Estuary Restoration
BORING MB-4
Snohomish County, Washington
70
50
50
FL
ao
x
a>
c
�
U
30
'
@
a
lo
zo
�
10
GIL
or
C111.
10
0
0 10 20 30 40
50
60
70
80 90 100 110
Liquid Limit
- ILL
N
0
>J_
ZI
Q
a
c0
0
It0
°o
ro
N
N
N
N
Z
Q
H
F
QI
a
0
0
0
00
0
N
N
N
N
Sample
Depth
USCS
USCS
LL
PL
PI
WC
Gravel
Sand
Fines
<21um
Tested
Review
ASTM
Identification
(ft)
Symbol
Group Name
%
%
%
%
%
By
By
Std.
SHANNON & WILSON, INC. 400 NORTH 34TH STREET SUITE 100 SEATTLE, WASHINGTON 98103 MAIN (206) 632-8020 • FAX (206) 695-6777
SHANNON &WILSON, INC. PLASTICITY CHART
Meadowdale Beach
Park and Estuary Restoration
BORING MB-6
Snohomish County, Washington
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60
50
/
FL
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x
a>
c
/
U
30
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10
00 10 20 30 40
50 60
70 80 90 100 110
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N
H
0
>J_
Q
I
a
c0
d
a
0
°o
00
N
N
N
N
Z
Q
FI
H
Q�
Q
0
0
0
00
0
N
N
N
N
Sample
Depth
USCS
USCS
LL
PL
PI
WC
Gravel
Sand
Fines
<21um
Tested
Review
ASTM
Identification
(ft)
Symbol
Group Name
%
%
%
%
%
By
By
Std.
MB-6, S-23B
90.8
ML
Silt
26
28
NIP24.4
AKV
JFL
D4318
SHANNON & WILSON, INC. 400 NORTH 34TH STREET •SUITE 100 SEATTLE, WASHINGTON 98103 •MAIN (206) 632-8020 •FAX (206) 695-6777
SHANNON &WILSON, INC. PLASTICITY CHART
Meadowdale Beach
Park and Estuary Restoration
BORING MB-7
Snohomish County, Washington
70
50
50
FL
ao
x
a>
c
�
U
30
'
@
a
lo
zo
�
10
GIL
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C111.
10
0
0 10 20 30 40
50
60
70
80 90 100 110
Liquid Limit
- ILLrou
N
0
>J_
ZI
Q
a
c0
0
It0
°o
ro
N
N
N
N
Z
Q
H
F
QI
a
0
0
0
00
0
N
N
N
N
Sample
Depth
USCS
USCS
WC
Gravel
Sand
Fines
<21um
Tested
Review
ASTM
Identification
(ft)
Symbol
Group Name
SHANNON & WILSON, INC. 400 NORTH 34TH STREET SUITE 100 SEATTLE, WASHINGTON 98103 MAIN (206) 632-8020 • FAX (206) 695-6777
SHANNON &WILSON, INC. PLASTICITY CHART
Meadowdale Beach
Park and Estuary Restoration
BORING MB-8
Snohomish County, Washington
70
60
50
FL
ao
x
a>
c
�
U
30
'
@
a
lo
loe
10
0
0 10 20 30 40
50
60
70
80 90 100 110
Liquid Limit
- LL
ro
N
0
c7
>J_
Q
I
a
c0
cS
a
0
oo
oo
N
N
N
N
Z
Q
FI
H
Q�
Q
0
0
0
00
00
N
N
N
N
Sample
Depth
USCS
USCS
LL
PL
PI
WC
Gravel
Sand
Fines
<21um
Tested
Review
ASTM
Identification
(ft)
Symbol
Group Name
%
%
%
%
%
By
By
Std.
FMB-8, S-5
12.5
CL
Lean Clay with Sand
31
22
9
25.1
AKV
JFL
D4318
FMB-8, S-9A
25.0
CL-ML
Silty Clay
29
22
7
22.7
AKV
JFL
D4318
SHANNON & WILSON, INC. 400 NORTH 34TH STREET •SUITE 100 SEATTLE, WASHINGTON 98103 •MAIN (206) 632-8020 •FAX (206) 695-6777
SHANNON WALSON, INC.
APPENDIX C
GEOPHYSICAL SURVEYS
21-1-22288-060
SHANNON MLSON, INC.
APPENDIX C
GEOPHYSICAL SURVEYS
TABLE OF CONTENTS
REPORTS
Global Geophysics, 2016, Report for the ground penetration radar survey at Meadowdale Beach
Park, Edmonds, WA: Report prepared by Global Geophysics, Redmond, Wash., 105-
0419.001, for Shannon & Wilson, Inc., Seattle, Wash., December 7.
Global Geophysics, 2017a, GPR survey line location map (fig. 1-A) and interpreted GPR
anomalies (fig. 1-B) [rev.], in, Report for the ground penetration radar survey at
Meadowdale Beach Park, Edmonds, WA: Report prepared by Global Geophysics,
Redmond, Wash., 105-0419.001, for Shannon & Wilson, Inc., Seattle, Wash., February 7.
Global Geophysics, 2017b, Report for the ground penetration radar and electrical resistivity
tomography surveys at Meadowdale Beach Park, Edmonds, WA: Report prepared by
Global Geophysics, Redmond, Wash., 105-0419.002, for Shannon & Wilson, Inc.,
Seattle, Wash., May 1.
21-1-22288-060-R1-AC/wp/lkn 21-1-22288-060
C-i
SHANNON MLSON, INC.
GLOBAL GEOPHYSICS REPORT, 2016
21-1-22288-060
Global Geophysics
P. O. Box 2229
Redmond, WA 98073-2229
December 7, 2016
Shannon & Wilson, Inc.
400 North 34th Street, Suite 100
Seattle, Washington, 98103
ATTENTION: Mr. Matthew Gibson
Tel: 425-890-4321
Fax:206-582-0838
Our ref: 105-0419.001
RE: REPORT FOR THE GROUND PENETRATION RADAR SURVEY AT
MEADOWDALE BEACH PARK, EDMONDS, WA
Dear Mr. Gibson:
This letter report presents the results of the geophysical survey performed by Global
Geophysics on November 8, 2016 at Meadowdale Beach Park, Edmonds, WA. The
objectives of the studies are to locate buried objects, such as foundations.
GEOPHYSICAL METHODS, INSTRUMENTATION AND FIELD PROCEDURES
Ground penetrating radar (GPR) was used to detect any discrete objects.
Ground Penetrating Radar
The GPR method uses electromagnetic pulses, emitted at regular intervals by an antenna to
map subsurface features. The electromagnetic pulses are reflected where changes in
electrical properties of materials occur such as changes in lithology or where underground
utilities are present. The reflected electromagnetic energy is received by an antenna,
converted into an electrical signal, and recorded on the GPR unit. The data is recorded and
viewed in real time on a graphical display that depicts a continuous profile or cross-section
image of the subsurface directly beneath the path of the antenna.
The depth of penetration of the GPR signal varies according to antenna frequency and the
conductivity of the subsurface material. The depth of subsurface penetration with GPR
decreases with an increase in the frequency of the antenna and an increase in soil
conductivity. Low frequency antennas (50 to 500 MHz) provide the best compromise
between obtaining good subsurface penetration and resolution.
Global Geophysics
Shannon & Wilson, Inc. December 7, 2016
Mr. Matthew Gibson 2 106-0419.001
The data were collected along the same EM transects at a 2.5 foot interval using Geophysical
Survey Systems, Inc. (GSSI) SIR 2000 GPR system with antennas having a center frequency
of 200 MHz. The data was digitally recorded for post processing.
RESULTS
The GPR anomalies are shown in Figure 1. The GPR anomalies are the inverted hyperbolic
curves, which are the refracted waves from discrete objects, such as debris and boulders. The
clusters of GPR anomalies within dashed orange lines are likely related to the remnant of
abandoned structures. The area within the dashed blue line is interpreted as buried swimming
pool due to the flat concrete floor with reinforced rebars.
LIMITATIONS OF GEOPHYSICAL METHODS
Global Geophysics services are conducted in a manner consistent with the level of care and
skill ordinarily exercised by other members of the geophysical community currently
practicing under similar conditions subject to the time limits and financial and physical
constraints applicable to the services. GPR is a remote sensing geophysical method that may
not detect all buried objects. Furthermore, it is possible that interpreted features may upon
intrusive sampling prove to have been misinterpreted or mis-located. Where interpretation
from geophysical data is an important element for cost or safety of operations, it should
always be checked for reasonableness against known or expected subsurface data, and
verified at critical locations by physical means such as probing or drilling. Cautious and safe
operating practices that will preserve the integrity of subsurface objects should always be
used above and in the vicinity of known or possible objects.
If you have any comments or questions, please contact Dr. John Liu at 425-890-4321.
Sincerely,
Global Geophysics
John Liu, Ph.D., R.G.
Principal geophysicist
Global Geophysics
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Legend:
Clusters of GPR anomalies likely related to buried foundations or structures
Interpreted pool location
11111111
Oft 25 ft 50 ft
SHANNON MLSON, INC.
GLOBAL GEOPHYSICS REPORT, 2017A
21-1-22288-060
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PROJECT
Meadowdale Beach Park
0 ft 30 ft 60 ft Edmonds, WA
TITLE
GPR survey line location map
Global Geophysics Project#:106-0419,00o F11 EN, GPRNS1EW-----
DESIGN r ASSHOWPo RE..
P.O. Box 2229 CADD JL
Redmond, WA 98073-2229
Tel: 425-890-4321 CHECK JL FIGURE 1-A
REVIEW
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Legend:
Shallow GPR Anomalies (mostly less than 4')
Deep GPR Anomalies (mostly greater than 5')
0 ft 30 ft 60 ft
SHANNON MLSON, INC.
GLOBAL GEOPHYSICS REPORT, 2017B
21-1-22288-060
Global Geophysics
P. O. Box 2229
Redmond, WA 98073-2229
May 1, 2017
Shannon & Wilson, Inc.
400 North 34th Street, Suite 100
Seattle, Washington, 98103
ATTENTION: Mr. Tyler Stephens
Tel: 425-890-4321
Fax:206-582-0838
Our ref: 106-0419.002
RE: REPORT FOR THE GROUND PENETRATION RADAR AND ELECTRICAL
RESISTIVITY TOMOGRAPHY SURVEYS AT MEADOWDALE BEACH PARK,
EDMONDS, WA
Dear Mr. Stephens:
This letter report presents the results of the geophysical surveys performed by Global
Geophysics on April 1 lth and 12th, 2017 at Meadowdale Beach Park, Edmonds, WA. The
objectives of the studies are to locate buried objects in the abutment of the railroad tracks.
GEOPHYSICAL METHODS, INSTRUMENTATION AND FIELD PROCEDURES
Ground penetrating radar (GPR) and electrical resistivity tomography were used for this
project. The followings describe the methods, field procedures and results.
Ground Penetrating Radar
The GPR method uses electromagnetic pulses, emitted at regular intervals by an antenna to
map subsurface features. The electromagnetic pulses are reflected where changes in
electrical properties of materials occur such as changes in lithology or where underground
utilities are present. The reflected electromagnetic energy is received by an antenna,
converted into an electrical signal, and recorded on the GPR unit. The data is recorded and
viewed in real time on a graphical display that depicts a continuous profile or cross-section
image of the subsurface directly beneath the path of the antenna.
The depth of penetration of the GPR signal varies according to antenna frequency and the
conductivity of the subsurface material. The depth of subsurface penetration with GPR
decreases with an increase in the frequency of the antenna and an increase in soil
Global Geophysics
Shannon & Wilson, Inc. May 1, 2017
Mr. Tyler Stephens 2 106-0419.002
conductivity. Low frequency antennas (50 to 500 MHz) provide the best compromise
between obtaining good subsurface penetration and resolution.
The data were collected along four transects using Geophysical Survey Systems, Inc. (GSSI)
SIR 2000 GPR system with antennas having a center frequency of 200 MHz. The data was
digitally recorded for post processing.
Electrical Resistivity Tomography (ERT)
The electrical resistivity tomography technique maps differences in the electrical properties
of geologic materials. These differences can result from variations in lithology, water
content, and pore -water chemistry. The method involves transmitting an electric current into
the ground between two electrodes and measuring the voltage between two other electrodes.
The direct measurement is an apparent resistivity of the area beneath the electrodes that
includes deeper layers as the electrode spacing is increased. Recent advances in technology
permit rapid collection of multiple soundings, using up to 56 electrodes for each spread. The
data are modeled to create a 2-D geo-electric cross-section that is useful for mapping both
vertical and horizontal variations of the subsurface strata.
The data were acquired along two transects with an AGI SuperSting R8 using up to 56
electrodes spaced at a 5 feet interval. Once the electrode array was installed in the ground,
multiple soundings were automatically carried out by the control unit. Downloading and
routine modeling of the data was done on -site to provide preliminary analysis and QA/QC of
the data. These results were displayed on a color monitor as cross-section that highlight
changes in resistivity with depths along the transects.
RESULTS
The line locations are shown in Figure 1. The GPR profiles with interpreted anomalies are
presented in Figure 2. The GPR anomalies are the inverted hyperbolic curves, which are the
refracted waves from discrete objects, such as boulders. The dashed green line is interpreted
as bottom of the fill. There are more GPR anomalies on Transect 1 and less GPR anomalies
on Transect 4. The thickness of the fill increases from Transect I toward Transect 4.
The resistivity profiles are presented in Figure 3. Three resistivity layers are evident. The first
layer is inhomogeneous, which correlates with fill materials with mix of coarse and fine
materials (higher resistivity correlates with coarser materials such as boulder and gravels).
The 2nd layer with resistivity less than 100 ohm-m is interpreted as beach sand with brine
water. The basal layer with high resistivity is interpreted as coarse materials with freshwater
discharge.
Global Geophysics
Shannon & Wilson, Inc. May 1, 2017
Mr. Tyler Stephens 3 106-0419.002
LIMITATIONS OF GEOPHYSICAL METHODS
Global Geophysics services are conducted in a manner consistent with the level of care and
skill ordinarily exercised by other members of the geophysical community currently
practicing under similar conditions subject to the time limits and financial and physical
constraints applicable to the services. GPR and ERT are remote sensing geophysical
methods that may not detect all buried objects. Furthermore, it is possible that interpreted
features may upon intrusive sampling prove to have been misinterpreted or mis-located.
Where interpretation from geophysical data is an important element for cost or safety of
operations, it should always be checked for reasonableness against known or expected
subsurface data, and verified at critical locations by physical means such as probing or
drilling. Cautious and safe operating practices that will preserve the integrity of subsurface
objects should always be used above and in the vicinity of known or possible objects.
If you have any comments or questions, please contact Dr. John Liu at 425-890-4321.
Sincerely,
Global Geophysics
John Liu, Ph.D., R.G.
Principal geophysicist
Global Geophysics
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Global Geophysics Prq�#. 106-0419002 FILE No. GPR EW
I
DESIGN I ISCALE ASSHOWN IREV.
P.O. BOX 2229 L JL
Te1425-890-432Red d WA 073-2229 CHECK JL FIGURE 1
A
-
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Transect 1
GPR anomaly GPR anomaly GPR anomaly
GPR anomaly GPR anomaly Distance (ft)
Zone of boulders and gravels
GPR
anomaly 11
0 ft N
20ftN 40ftN 60ftN 80ftN
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()
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PROJECT
Meadowdale Beach Park
Edmonds, WA
0 ft 20 ft
40 ft
TITLE
GPR Profiles
Global Geophysics Project#:1060419.000 FILE No. GPR EW
DESIGN SCALE ASSHOWN IREV.
P.O. Box2229
CADD JL
Redmond, WA 98073-2229
Tel: 425-890-4321 CHECK JL FIGURE 2
REVIEW
Transect 2
0 ft 20 ft 40 ft 60 ft 80 ft
10
0 0
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Transect 4
0 ft
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100 ft 120 ft 140 ft 160 ft 180 ft 200 ft 220 ft 240 ft 260 ft 280 ft 300 ft
Distance (ft)
20 ft 40 ft 60 ft 80 ft 100 ft 120 ft 140 ft 160 ft 180 ft 200 ft 220 ft 240 ft 260 ft 280 ft 300 ft
E E E E E E E E E E
E E E E E E E E E E E E E E E E E E E
O O O E E E E
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M CO N N — —— 00 N LC) M N
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APPENDIX D
HISTORICAL RESEARCH
SHANNON MLSON, INC.
21-1-22288-060
APPENDIX D
HISTORICAL RESEARCH
TABLE OF CONTENTS
SHANNON MLSON, INC.
Page
D.1 INTRODUCTION)......................................................................................................... D-1
D.2 HISTORICAL RECORD SUMMARIES.......................................................................
D-1
D.2.1
GNRHS Reference Sheet No. 156....................................................................
D-2
D.2.2
AFE 9663(1904)..............................................................................................
D-2
D.2.3
AFE 11623 (1905)............................................................................................
D-2
D.2.4
AFE 12062 (1906)............................................................................................
D-2
D.2.5
AFE 13340 (1907)............................................................................................
D-3
D.2.6
AFE 15426(1908)............................................................................................
D-3
D.2.7
AFE 24396(1915)............................................................................................
D-3
D.2.8
AFE 25652(1924)............................................................................................
D-3
D.2.9
AFE 37050(1928)............................................................................................
D-4
D.2.10
AFE 46181(1932)............................................................................................
D-4
D.2.11
AFE 8502 (1936)..............................................................................................
D-4
D.2.12
AFE 56925(1939)............................................................................................
D-4
D.2.13
AFE 56987(1940)............................................................................................
D-4
D.2.14
AFE 64136(1942)............................................................................................
D-5
D.2.15
AFE 76795 (1948)............................................................................................
D-5
D.2.16
AFE 87988(1956)............................................................................................
D-5
D.3 REFERENCE.................................................................................................................. D-5
FIGURES
D-1
AFE-13340
D-2
AFE-15426
D-3
AFE-25652
D-4
AFE-56987
21-1-22288-060-xi f AD/wp/lkn 21-1-22288-060
D-1
APPENDIX D
HISTORICAL RESEARCH
D.1 INTRODUCTION)
SHANNON MLSON, INC.
This appendix presents a summary of historical records provided by the Great Northern Railway
Historical Society (GNRHS). We contacted the GNRHS and were informed that their volunteers
would be able to assist with archive research. After initial discussions regarding our topic of
interest, they directed us to one of their publications, Reference Sheet number 156, titled
"Construction of Great Northern's Seawall and Double Track Between Seattle and Everett,
Washington (Intlekofer, 1989), and agreed to assist with researching their archives further.
The GNRHS headquarters is in St. Paul, Minnesota, and they have a local archive in Burien,
Washington. After they completed their initial search, we arranged to meet at their Burien
archive to review locally available materials. During that meeting, GNRHS provided scanned
images of selected documents, and indicated they would search the archives in St. Paul,
Minnesota for additional records. After several weeks, we received notification that they had
scanned a number of additional records which they provided on a DVD.
Most of the reviewed historical records are organized by Authority for Expenditure numbers
(AFEs), dated between 1904 and 1964. The AFE archives contain written work orders, material
quantity records, and track schematics showing where construction had been completed and
where construction was proposed. The schematics have railroad milepost along the bottom of
the drawing, and separate areas to record progress for seawall construction, grading, and track
laying. The AFE records are dated between 1906 and 1956.
The project site is located between Mileposts 21.8 and 22.0. We compared observed site features
to those described in historical documents and found relatively good agreement. In particular,
we found seawall structures north and south of the project site, which are described in the
historical documents and are in place today, and found reference to the existing concrete box
culvert at the correct milepost in the historical documents.
D.2 HISTORICAL RECORD SUMMARIES
The following sections provide a brief synopsis of the information in the AFEs and other
research material obtained from the GNRHS.
21-1-22288-060-xi f-AD/wp/lkn 21-1-22288-060
D-1
SHANNON MLSON, INC.
D.2.1 GNRHS Reference Sheet No. 156
This document summarizes the construction of Great Northern Railway's (GNR's)
seawall and second track between Seattle and Everett, Washington. It describes construction of
the original rail line, completed in 1891, and the planning that began in 1905 for construction of
a second track. AFE's were issued beginning in 1906 to begin construction of the second track
embankment and seawall. The document summarizes AFE 13340, under which work started in
1907, covering the project area and extending several miles north and south. This document
contains no detailed description of embankment construction in the project area, and does not
indicate a temporary trestle was constructed at the site. A cross section in the document depicts
new track and seawall, which includes a seawall constructed of large -diameter face rock along
the outboard embankment face. The document confirms that the seawall was not continuous,
with areas in Richmond Beach, Edmonds, and Mukilteo, and a few others where the city -owned
land west of the tracks, so a seawall was not necessary.
D.2.2 AFE 9663 (1904)
We obtained information locally in Burien, and additional documents related to the AFE
were discovered during research in St. Paul. The documents from Burien include a letter to
Great Northern's Chief engineer detailing work for repair of damaged bulkheads and proposed
second mainline construction between Ballard and Everett. The scope of work listed in the letter
consists of clearing and grubbing, bulkhead construction, and grading and construction of
bridges and culverts. Additional documents obtained from St. Paul archives include cost and
estimated quantities for the proposed work and blueprints detailing the progress of the proposed
improvements between Ballard and Everett. In the project area, grading and riprap placement
was complete as of 1903 (date shown on blueprint); 22 culverts were also constructed between
mileposts 21 and 22.
D.2.3 AFE 11623 (1905)
AFE 11623 does not include the project area but includes blueprints showing proposed
changes to existing track between Mileposts 11, 13, 19, and 20. The proposed track changes are
shown in red on the blueprints and proposed work near Milepost 20 includes straightening of the
alignment mentioned in AFE 9663.
D.2.4 AFE 12062 (1906)
The document contains a single blueprint detailing progress of grading and seawall
construction between Metum and Everett Junction. In the project area, construction of the
seawall and grading for preparation of installing second mainline is complete by 1905.
21-1-22288-060-x1f-AD/wp/lkn 21-1-22288-060
D-2
SHANNON MLSON, INC.
D.2.5 AFE 13340 (1907)
AFE 13340 contains a single blueprint (Figure D-1), similar to AFE 12062, showing
progress of seawall construction, grading, and track construction between Mileposts 8 and 33.
Consistent with the progress noted in AFE 12062, the seawall and grading in the project area is
complete, but no new track is placed. Notations on the blueprint show that the wall type
constructed in the project area is a "Slope Wall" as compared to a "seawall" as noted in other
areas. In the areas where grading is not complete, "hydraulic fill" is called for.
D.2.6 AFE 15426 (1908)
AFE 15426 contains a single blueprint (Figure D-2) consistent with the previous two
AFEs (12062 and 13340) detailing progress of construction of new track, grading, and seawall
construction between Ballard and Everett. The blueprint shows the final alignment of the double
track, highlighting the areas of the existing main that are not be changed and the second mainline
yet to be constructed. At approximately Mileposts 21 and 15, a temporary wooden trestle is
called out in the notes.
D.2.7 AFE 24396 (1915)
AFE 24396 shows location on a single blueprint of barbed wire fence construction within
the project area. The drawing shows a 4-foot by 4-foot by 62-foot-long double timber culvert at
the approximate location of the existing concrete culvert. Township and Range values listed on
the blueprint for the section of fence completed August 1914 correspond to the project area. The
mileposts listed on the blueprint correspond to current BNSF Railway Company mileposts for
the project area.
D.2.8 AFE 25652 (1924)
The project area is not included in this AFE, but design drawings of three
bulkhead/seawall designs are included (Figure D-3), showing the stations where they are to be
constructed. One of the seawall designs is for areas that contain temporary wooden trestles. The
design drawings show the bents for the bridge to be buried in fill after construction of the wall.
The stations where this type of seawall is constructed do not fall within the project limits.
21-1-22288-060-xi f-AD/wp/lkn 21-1-22288-060
D-3
SHANNON MLSON, INC.
D.2.9 AFE 37050 (1928)
AFE 37050 details the placement of riprap between Ballard and Everett Junction to repair
storm damage during the winter of 1927-1928. In the project area between Mileposts 21 and 22,
110 cubic yards of riprap were placed to repair storm damage to seawall.
D.2.10 AFE 46181 (1932)
Work completed for AFE 46181 consists of adjusting account and records for filled
culverts and plank crossings that were removed. Additional work consisted of adjusting signage
for existing culverts and crossing to match track charts and adding signs to locations where none
exist. Most of the work is located outside the project area. A single private crossing is listed as
removed within project limits.
D.2.11 AFE 8502 (1936)
The only document included with the AFE is a track chart between Ballard and Everett
showing locations where improvement work on the seawall is required. No work is indicated
within the project limits. Notes within the project area suggest no repairs to the track or seawall.
D.2.12 AFE 56925 (1939)
Work completed for AFE 56925 consists of reinforcing damaged portions of the seawall
and raising the height of the existing wall to protect the track and ballast from wave erosion
between Seattle and Everett. In the project area, 300 cubic yards of large riprap were placed to
raise the top of the slope protection.
D.2.13 AFE 56987 (1940)
AFE 56987 consists of a single blueprint (Figure D-4) showing construction plans for a
standard 7-foot, 6-inch by 6-foot by 39-foot culvert. Notation on the print states that the plan for
this culvert is for replacement of 36-inch concrete culvert 1'/a miles north of Meadowdale,
Washington. The drawing identifies the structure as culvert number 21.83, which is consistent
with railroad practice to number culverts and structures according to their milepost location
along the rail line. Milepost 21.83 corresponds well to the location, and dimensions shown in the
plan match well with dimensions for the existing culvert at the project site. Plan view of the
culvert shows a width of 10 feet from outer wall to outer wall.
21-1-22288-060-xi f-AD/wp/lkn 21-1-22288-060
D-4
SHANNON MLSON, INC.
D.2.14 AFE 64136 (1942)
AFE 64136 consists of a written work order for replacing of 13 damaged timber culverts
with concrete pipes and abandoning 6 culverts between Seattle and Everett. Supporting
documents in the AFE provide location and status of culverts replaced, and indicate that no work
was performed in the project area.
D.2.15 AFE 76795 (1948)
AFE 76795 details the construction of a 630-foot-long scrap rail and timber bulkhead to
provide catchment and stabilization for landslide activity just south of the project area. The
rail/timber wall terminates at the south end of the project area and continues south for 630 feet.
The location of the wall coincides with the existing slope at the south boundary of the park.
D.2.16 AFE 87988 (1956)
AFE 87988 lists several locations between Mileposts 7 and 23 where construction of a
rail and timber fence/bulkhead is required to reduce hazard from landslides. The location with
the highest priority is located at Milepost 21.6. This is very close to the area called out for
construction of the same structure in AFE 76795. The second document included in the AFE is a
track chart showing location of structures, condition of seawall, and elevation changes from
Ballard to Everett. The map shows priority order of slide fences/bulkheads at the bottom of the
document. The location with the highest priority is Milepost 21.6, located south of project area.
The elevation shown on the track charts shows the slopes to the north and south of the park
limits. In the notes section at the top of the document, a 7.5-foot by 6-foot concrete box culvert
is shown in the project area that corresponds to the existing structure and references AFE 56987,
described above.
D.3 REFERENCE
Intlekofer, C. E, 1989, Construction of Great Northern's seawall and double track between
Seattle and Everett, Washington: Great Northern Railway Historical Society Reference
Sheet no. 156, p. 1-8, December.
21-1-22288-060-xi f-AD/wp/lkn 21-1-22288-060
D-5
IC L/-I rI II IICU. L/ IJ14U 10 I.LU rlVI
NOTES
1. Original Scan obtained from Great Northern Railway Historical Society
IC U-L rI 11]ICU. Ll IJ14U 10 I.41 rIV1
4
NOTES
1. Original Scan obtained from Great Northern Railway Historical Society
2 No Callout of Wooden Trestle between Mileposts 21 and 22.
I _0
Meadowdale Beach
Park and Estuary Restoration Project
Snohomish County, Washington
GNRHS HISTORICAL RESEARCH
AFE 15426
February 2018 21-1-22288-060
SHANNON & WILSON, INC. FIG. D-2
Geotechnical and Environmental Consultants
IC L/-J rI II IICU. Ll IJ14U 10 I.44 rlVI
NOTES
1. Original Scan obtained from Great Northern Railway Historical Society
2 Approximate Station of Project Area is 1260+00
3 Bulkhead Style 1 utilized between stations 64+69 - 186+00. Bulkhead Type
2 utilized between between 199+00 - 207+30. Bulkhead Type 3 Utilized
between Stations 186+00 - 183+00
SHANNON MWILSON. INC.
APPENDIX E
IMPORTANT INFORMATION ABOUT YOUR
GEOTECHNICAL/ENVIRONMENTAL REPORT
21-1-22288-060
- SHANNON & WILSON, INC. Attachment to and part of Report 21-1-22288-060
- Geotechnical and Environmental Consultants
Date: February 16, 2018
- To: Snohomish County Parks & Recreation
Attn: Ms. Logan Daniels, PE
IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL/ENVIRONMENTAL
•:
CONSULTING SERVICES ARE PERFORMED FOR SPECIFIC PURPOSES AND FOR SPECIFIC CLIENTS.
Consultants prepare reports to meet the specific needs of specific individuals. A report prepared for a civil engineer may not be adequate
for a construction contractor or even another civil engineer. Unless indicated otherwise, your consultant prepared your report expressly
for you and expressly for the purposes you indicated. No one other than you should apply this report for its intended purpose without
first conferring with the consultant. No party should apply this report for any purpose other than that originally contemplated without
first conferring with the consultant.
THE CONSULTANT'S REPORT IS BASED ON PROJECT -SPECIFIC FACTORS.
A geotechnical/environmental report is based on a subsurface exploration plan designed to consider a unique set of project -specific
factors. Depending on the project, these may include: the general nature of the structure and property involved; its size and
configuration; its historical use and practice; the location of the structure on the site and its orientation; other improvements such as
access roads, parking lots, and underground utilities; and the additional risk created by scope -of -service limitations imposed by the
client. To help avoid costly problems, ask the consultant to evaluate how any factors that change subsequent to the date of the report
may affect the recommendations. Unless your consultant indicates otherwise, your report should not be used: (1) when the nature of
the proposed project is changed (for example, if an office building will be erected instead of a parking garage, or if a refrigerated
warehouse will be built instead of an unrefrigerated one, or chemicals are discovered on or near the site); (2) when the size, elevation,
or configuration of the proposed project is altered; (3) when the location or orientation of the proposed project is modified; (4) when
there is a change of ownership; or (5) for application to an adjacent site. Consultants cannot accept responsibility for problems that may
occur if they are not consulted after factors which were considered in the development of the report have changed.
SUBSURFACE CONDITIONS CAN CHANGE.
Subsurface conditions may be affected as a result of natural processes or human activity. Because a geotechnical/environmental report
is based on conditions that existed at the time of subsurface exploration, construction decisions should not be based on a report whose
adequacy may have been affected by time. Ask the consultant to advise if additional tests are desirable before construction starts; for
example, groundwater conditions commonly vary seasonally.
Construction operations at or adjacent to the site and natural events such as floods, earthquakes, or groundwater fluctuations may also
affect subsurface conditions and, thus, the continuing adequacy of a geotechnical/environmental report. The consultant should be kept
apprised of any such events, and should be consulted to determine if additional tests are necessary.
MOST RECOMMENDATIONS ARE PROFESSIONAL JUDGMENTS.
Site exploration and testing identifies actual surface and subsurface conditions only at those points where samples are taken. The data
were extrapolated by your consultant, who then applied judgment to render an opinion about overall subsurface conditions. The actual
interface between materials may be far more gradual or abrupt than your report indicates. Actual conditions in areas not sampled may
differ from those predicted in your report. While nothing can be done to prevent such situations, you and your consultant can work
together to help reduce their impacts. Retaining your consultant to observe subsurface construction operations can be particularly
beneficial in this respect.
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A REPORT'S CONCLUSIONS ARE PRELIMINARY.
The conclusions contained in your consultant's report are preliminary because they must be based on the assumption that conditions
revealed through selective exploratory sampling are indicative of actual conditions throughout a site. Actual subsurface conditions can
be discerned only during earthwork; therefore, you should retain your consultant to observe actual conditions and to provide conclusions.
Only the consultant who prepared the report is fully familiar with the background information needed to determine whether or not the
report's recommendations based on those conclusions are valid and whether or not the contractor is abiding by applicable
recommendations. The consultant who developed your report cannot assume responsibility or liability for the adequacy of the report's
recommendations if another party is retained to observe construction.
THE CONSULTANT'S REPORT IS SUBJECT TO MISINTERPRETATION.
Costly problems can occur when other design professionals develop their plans based on misinterpretation of a
geotechnical/environmental report. To help avoid these problems, the consultant should be retained to work with other project design
professionals to explain relevant geotechnical, geological, hydrogeological, and environmental findings, and to review the adequacy of
their plans and specifications relative to these issues.
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Final boring logs developed by the consultant are based upon interpretation of field logs (assembled by site personnel), field test results,
and laboratory and/or office evaluation of field samples and data. Only final boring logs and data are customarily included in
geotechnical/environmental reports. These final logs should not, under any circumstances, be redrawn for inclusion in architectural or
other design drawings, because drafters may commit errors or omissions in the transfer process.
To reduce the likelihood of boring log or monitoring well misinterpretation, contractors should be given ready access to the complete
geotechnical engineering/environmental report prepared or authorized for their use. If access is provided only to the report prepared for
you, you should advise contractors of the report's limitations, assuming that a contractor was not one of the specific persons for whom
the report was prepared, and that developing construction cost estimates was not one of the specific purposes for which it was prepared.
While a contractor may gain important knowledge from a report prepared for another party, the contractor should discuss the report with
your consultant and perform the additional or alternative work believed necessary to obtain the data specifically appropriate for
construction cost estimating purposes. Some clients hold the mistaken impression that simply disclaiming responsibility for the accuracy
of subsurface information always insulates them from attendant liability. Providing the best available information to contractors helps
prevent costly construction problems and the adversarial attitudes that aggravate them to a disproportionate scale.
READ RESPONSIBILITY CLAUSES CLOSELY.
Because geotechnical/environmental engineering is based extensively on judgment and opinion, it is far less exact than other design
disciplines. This situation has resulted in wholly unwarranted claims being lodged against consultants. To help prevent this problem,
consultants have developed a number of clauses for use in their contracts, reports, and other documents. These responsibility clauses
are not exculpatory clauses designed to transfer the consultant's liabilities to other parties; rather, they are definitive clauses that identify
where the consultant's responsibilities begin and end. Their use helps all parties involved recognize their individual responsibilities and
take appropriate action. Some of these definitive clauses are likely to appear in your report, and you are encouraged to read them closely.
Your consultant will be pleased to give full and frank answers to your questions.
The preceding paragraphs are based on information provided by the
ASFE/Association of Engineering Firms Practicing in the Geosciences, Silver Spring, Maryland
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