PanGEO Geotech Report.pdfDecember 24, 2009
Revised on February 19, 2010
PanGEO Project No. 09-146
Mr. Steve Clarice, P.E.
Gray & Osborne, Inc.
701 Dexter Avenue North, Suite 200
Seattle, Washington 98109
Subject: GEOTECHNICAL REPORT
PanGE&
C O R P O R A T 6 0
Geotechnical & Earthquake
Erlgineerin, Cnnsuhanis
Storm Sewer Pipeline Improvements
1025 —12"' Avenue North, Edmonds, Washington
Dear Mr. Clarice,
Attached please find our geotechnical report prepared for the storm sewer improvements
project in Edmonds, Washington. Based on the results of our subsurface exploration
program, the proposed storm sewer alignment is underlain by approximately 3'/z to 6 feet
of fill overlying glacial till. It is our opinion that installation of the proposed 12 -inch new
sewer line using trenchless method (i.e. directional drilling) is'appropriate. In addition,
the site soils will also provide adequate support for catch basins.
We appreciate the opportunity to be of service. Should you have any questions regarding
this report, please do not hesitate to call.
Sincerely,
Siew L. Tan, P.E.
Principal Geotechnical Engineer
?021 A N inor AV enue I
Seattle. WA 98102
T.(206)262-0370
F. (206) 262-0374
TABLE OF CONTENTS
Section Paye
1.0 SITE AND PROJECT DESCRIPTION.....................................................................1
2.0 SUBSURFACE EXPLORATION............................................................................1
Figure A-1
3.0 LABORATORY TESTING.......................................................................................2
Figure A-2
4.0 SUBSURFACE CONDITIONS................................................................................2
Figure A-3
4.1 SOIL...............................................................................................................2
Figure A-4
4.2 GROUNDWATER.............................................................................................3
5.0 GEOLOGIC HAZARDS ASSESSMENT.............................................................................3
5.1 LANDSLIDE HAzARDs....................................................................................3
5.2 EROSION HAZARDS........................................................................................3
6.0 GEOTECHNICAL RECOMMENDATIONS...........................................................4
6.1 PIPE INSTALLATION USING DIRECTIONAL DRILLING METHOD .......................4
6.1.1 General...........................................................................................4
6.1.2 Soil Conditions................................................................................4
6.1.3 Contractor Qualifications and Equipment.....................................5
6.2 CATCH BASIN STRUCTURES............................................................................5
6.2.1 Foundation Support........................................................................5
6.2.2 Lateral Earth Pressures..................................................................5
6.2.3 Backfill Around Catch Basin..........................................................6
6.3 TEMPORARY EXCAVATIONS AND SHORING.....................................................6
6.4 WET WEATHER CONSTRUCTION.....................................................................6
7.0 UNCERTAINTY AND LIMITATIONS..................................................................7
8.0 REFERENCES..........................................................................................................9
LIST OF FIGURES
Figure 1. Vicinity Map
Figure 2. Site Plan and Profile
LIST OF APPENDICES
Appendix A Summary Boring Logs
Figure A-1
Terms and Symbols for Boring and Test Pit Logs
Figure A-2
Log of Test Boring BH -1
Figure A-3
Log of Test Boring 131-1-2
Figure A-4
Log of Test Boring BH -3
Appendix B Laboratory Test Results
Figures B-1 Grain Size Distribution
GEOTECHNICAL REPORT
STORM SEWER PIPELINE IMPROVEMENTS
1025-12 T" AVENUE FORTH, EDMONDS, WASHINGTON
As requested, PanGEO has completed a geotechnical engineering study to assist the project team
with the design of the proposed Storm Sewer pipeline Improvements project in the City of
Edmonds, Washington. Our work was performed in general accordance with our proposal dated
August 11, 2009, which was subsequently authorized by Gray & Osborne on October 26, 2009.
Our service scope included performing a site reconnaissance, drilling three borings, and
developing the conclusions and recommendations presented in this report.
1.0 SITE AND PROJECT DESCRIPTION
The project site is located at 1205 — 12"' Avenue North in Edmonds, Washington. The
approximate location of the site is shown in Figure 1. We understand that a new 12 -inch
diameter storm drain pipeline will be installed to replace an existing one that is located below the
residence at 1205 — 12t" Avenue North. The proposed sewer line will start at 12"' Avenue North,
runs almost parallel to the south property line in east -west direction for approximately 126 feet,
and connects to the existing open ditch (see Figures 2 and Plate 1). The pipe line will have
relatively shallow cover of about 3 to 5 feet at the east and west ends, and will have thick cover
of about 13 feet at the middle portion. Due to the close proximity to the existing residence and
relatively steep slope ground, we understand that the pipeline likely will be installed using
trenchless methods in order to limit the ground disturbance. Two type 1 catch basins of about 6
to 7 deep are also planned at the east and west ends of the alignment.
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09-146 Stone Sewer Rpt Revldoc Page 1 PanGEO, Inc.
Geotechnical Engineering Report
Storm Sewer Improvements, 1205 — 12th Avenue N, Edmonds, Washington
Revised February 19 2010
penetration was recorded and is shown on the boring logs at the approximate sample depths.
The number of blows needed to advance the sampler the last 12 inches of an 18 -inch drive is
defined as the SPT N -value. The N -value provides an empirical measure of the relative density
of cohesionless soil, or the relative consistency of fine-grained (cohesive) soil.
A geotechnical engineer from PanGEO was present throughout the field exploration program to
observe the drilling, to collect soil samples, and to prepare descriptive logs of the explorations.
Soils were classified in general accordance with the guidelines shown on Figure A-1 in
Appendix A of this report. Summary boring logs are included as Figures A-2 through A-4.
The stratigraphic contacts shown on the summary logs represent the approximate boundaries
between soil types; actual stratigraphic contacts encountered at other locations in the field may
differ from the contact elevations shown on the logs, and may be gradual rather than abrupt. The
soil and groundwater conditions depicted are only for the specific date and locations reported,
and therefore, are not necessarily representative of other locations and times.
3.0 LABORATORY TESTING
Grain size distribution and natural moisture contents tests were conducted on selected soil
samples obtained from the borings. The moisture content of the selected soil samples are
indicated at the appropriate depths on the boring logs. The grain size distribution tests were
performed in general accordance with the procedure outlined in ASTM D422, and the results are
included in Figure B-1 of Appendix B.
4.0 SUBSURFACE CONDITIONS
4.1 Soil
According to the geology map of the area (Minard, J.P., 1983), the project site is underlain by
Vashon Glacial Till (Qvt). Vashon Glacial Till deposits are described by Minard as generally
consisting of a very dense, heterogeneous mixture of silt, sand and clay with gravel and cobbles.
Vashon Till typically exhibit low compressibility and high strength characteristics in its
undisturbed state.
The subsurface conditions encountered in our test borings are generally consistent with the
mapped geology. A generalized subsurface profile is shown in Figure 2. Additional details of
the site subsurface conditions are described below:
Fill — Approximately 3'/2 to 6 feet of fill was encountered in the borings. The fill was
generally loose to medium dense, with SPT N -values ranged from about 4 to 13 blows
per foot of penetration. The fill generally consisted of slightly silty to silty sand with
gravel. However, the nature and composition of the fill may vary significantly.
09-146 Storm Sewer Rpt Rev2.doc Page 2 PanGEO, Inc.
Geotechnical Engineering Report
Storm Sewer Improvements, 1205 — 12`h Avenue N, Edmonds, Washington
Revised February 19 2010
Till — Below the fill, all borings encountered dense to very dense, silty sand with gravel
to silty gravelly sand that extended to at least the maximum depths explored at 8 to I I
feet below the existing surface. We interpret this unit as glacial till. Although not
encountered in the test borings, cobbles and boulders and often present in this geologic
unit, and may be present along the alignment.
4.2 Groundwater
Groundwater was not encountered in the borings during drilling. However, perched groundwater
seepage may be present near the fill -till contact during the winter/spring months. In addition,
groundwater seepage is often present in sandy and gravelly zones of glacial till deposits. It
should be noted that groundwater conditions will vary depending on rainfall, local subsurface
conditions, season of the year, and other factors.
5.0 GEOLOGIC HAZARDS ASSESSMENT
Based on the City of Edmond's Geologic Hazards Maps, the project area is located in a mapped
erosion hazard area, and portion of the project area is mapped within a landslide hazard area. As
such, we conducted a geologic hazards assessment (Landslide Hazards and Erosion Hazards) for
the proposed storm sewer improvements as part of our study.
5.1 Landslide Hazard
Accordance to the City's Geologic Hazards Map, the western portion of the project area is
mapped within a landslide hazard area. As part of our study, we conducted a site reconnaissance
to observe signs of recent slope movement and instability at the subject property. Based on our
observations of ground features and the results of our field exploration (i.e. glacial till at shallow
depths), it is our opinion that the site is globally stable in its current configurations. As long as
no significant cut or fill will be made, the slope is expected to remain stable. However, given the
steepness of the slope, shallow surficial creep should be anticipated. Surficial creep is not
anticipated to adversely impact the global stability of the slope.
It is also our opinion that the proposed storm sewer improvements construction method, i.e.
directional drilling, to install the new storm sewer pipes and construction of the manhole
structures, will not adversely impact the overall stability of the site and surrounding properties,
provided that the recommendations presented in this report are properly incorporated into the
design and construction of the project. In addition, the proposed pipe is located within glacial
till (see Figure 3), and therefore not anticipated to be affected by surficial soil creep.
5.2 Erosion Hazards
The site is mapped within a potential erosion hazard area in accordance with the City of
Edmond's Geologic Hazards Map. Based on the borings excavated, the site soils encountered in
09-146 Storm Sewer Rpt Revldoc Mage 3 PanGEO, Inc..
Geotechnical Engineering Report
Storm Sewer Improvements, 1205 — 12th Avenue N, Edmonds, Washington
Revised February 19 2010
our borings exhibit low to moderate erosion potential if exposed to surface runoff. This is
consistent with our field observations during our site visit. However, in our opinion, the
potential erosion hazards at the site can be effectively mitigated with the best management
practice during construction and with properly designed and implemented landscaping for
permanent erosion control. During construction, the temporary erosion hazard can be effectively
managed with an appropriate erosion and sediment control plan, including but not limited to
installing silt fence at the construction perimeter, placing rocks or hay bales at the disturbed and
traffic areas, covering stockpile soil or cut slopes with plastic sheets, constructing a temporary
drainage pond to control surface runoff and sediment trap if needed, placing rocks at the
construction entrance, etc. Permanent erosion control measures for the disturbed areas should
consist of establishing the permanent vegetation or placing a geotextitle and gravel at the
disturbed ground surface.
6.0 GEOTECHNICAL RECOMMENDATIONS
6.1 Pipe Installation using Directional Drilling Method
6.1.1 General
It is our opinion that, given the limited site access and steep terrain, directional drilling is the
most appropriate method for installing the proposed sewer line. Directional drilling will
minimize the amount of ground disturbance for the project area. The only areas where ground
disturbance will occur are where enhance and exit pits will be needed.
Generally, directional drilling installation starts with the excavation of small entrance and exit
pits. A pilot hole is then bored. When the drill bit emerges at the exit pit, the drill bit is
removed, a reamer is installed, and the hole is back -reamed to the appropriate size to ensure the
pipes can be pulled and properly installed. Depending on the proposed diameter of the bore and
the soil conditions, reaming may require one or more passes. The pipe is then pulled into the
completed hole with the drill string. Mud slurry is circulated during drilling of the pilot hole,
reaming, and pull-back of the pipe. The slurry washes cuttings to the surface along the annulus
between the drill string and the hole wall during drilling. Slurry also reduces friction and
provides hole wall support during drilling, reaming, and pull-back of the pipe. Slurry will
remain in the annulus between pipe and reamed wall after pipe is installed. In our opinion, the
horizontal drilling operation and pipe installation will not adversely impact the site slope.
6.1.2 Soil Conditions
Based on the results of our field exploration, the soil condition along the proposed pipeline
alignment consists of 3 to 6 feet of undocumented fill overlying dense to very dense glacial till.
As indicated in Figure 2, we anticipate the proposed sewer line to be located mostly within the
glacial till consisting of silty sand with some to gravelly silty sand. Although not encountered in
the borings, cobble and boulders are frequently present in the glacial till. As such, the contractor
09-146 Storm Sewer Rpt Rev2.doc Page 4 PanGEO, Inc.
Geotechnical Engineering Report
Storm Sewer Improvements, 1205 — 12'1'Avenue N, Edmonds, Washington
Revised February 19 2010
should be prepared to deal with the cobbles and boulders during drilling if encountered. It
should be expected that the density and consistency of the till soils will vary considerably and
may include weathered and unweathered zones.
6.1.3 Contractor Qualifications and Equipment
The contractor should provide detailed information regarding their qualifications, including
years of experience and relevant references for completed installations. The submitted
information should also include the capabilities of the equipment and the qualifications of the
work crew. The equipment proposed should be capable of operating in a wide variety of soil
conditions, including very dense till with varying amounts of over -sized materials such as
cobbles and boulders.
6.2 Catch Basin Structures
6.2.1 Foundation Support
Based on the preliminary design plans, the bottom of the catch basins will be about 6 to 7 feet
below the existing surface. We anticipate native dense to very dense till to be present at the
foundation level. In our opinion, the native till soils will provide adequate support for the
proposed catch basin structures. For design purposes, we recommend that an allowable
maximum bearing pressure of 3,000 psf be used for evaluating the foundation support of the
catch basins. Settlements are anticipated to be less than '/2 inch for these structures under
anticipated loading conditions.
To provide a firm and uniform support for the manholes, a 6 -inch thick layer of crushed rock
(crushed surfacing top course) may be placed as a leveling course.
6.2.2 Lateral Earth Pressures
Any below -grade structures should be designed to resist lateral loads imposed by the
surrounding soils and applicable surcharge loads. For design purposes, the lateral pressure
should be computed using an equivalent fluid unit weight of 40 pcf, extending from the ground
surface to the base of the structures. This value is based on horizontal backfill conditions and
assumes that the backfill around the manhole structures is properly placed and compacted.
Where the structures will be located adjacent to or within the roadway, we recommend that a
uniform lateral pressure of 85 psf be included in the design calculations to account for traffic
surcharge. For design purposes, a friction coefficient of 0.4 and an allowable passive pressure of
400 pcf may be used. The recommended values include a factor of safety of at least 1.5.
09-146 Storm Sewer Rpt Rev2.doc Page 5 PanGEO, Inc.
Geotechnical Engineering Report
Storm Sewer Improvements, 1205 — 12t1i Avenue N, Edmonds, Washington
Revised February 19 2010
6.2.3 Backfill Around Catch Basin
The excavated space around catch basins should be properly backfilled to limit the potential of
fiiture settlement that could affect the future performance of adjacent structures. In addition, it is
also our opinion that the catch basins should be backfilled such that water would not accumulate
around the catch basins. As a result, we recommend that Control Density Fill (CDF) or lean -mix
concrete (1/3 to 1/2 sack of cement per yard) be used to backfilled the catch basins.
6.3 Temporary Excavations and Shoring
The temporary excavations for the catch basins may be up to about 7 feet deep. The excavations
will likely encounter loose to medium dense silty sand (fill) over dense to very dense till. The
excavation method and equipment should be determined by the contractor. It is our opinion that
conventional heavy excavators are capable of performing the excavations based on the
subsurface conditions encountered.
It is the contractor's responsibility to maintain safe working conditions, including temporary
excavation stability. All excavations should be conducted in accordance with all applicable
federal, state, and other local safety requirements. All excavations in excess of 4 feet in depth
should be sloped in accordance with Washington Administrative Code (WAC) 296-155, or be
shored. Based on the site conditions, we understand that space is available for unsupported open
cut excavations. For planning purpose, unsupported open cut excavations should be graded no
steeper than 1H:1 V. If sloped open excavations are not desired due to disruption to the roadway
and adjacent residential properties, it is our opinion that small trench boxes and/or steel plates
with hydraulic braces may be used to support the temporary excavations.
The adequacy and safety of the shoring installation should be made the sole responsibility of the
contractor. A qualified geotechnical engineer/shoring designer should be retained by the
contractor to design and evaluate the excavation and shoring systems used. An appropriate
safety factor should be included by the contractor's shoring designer. The excavation support
and shoring system used must comply with all applicable safety requirements. During
construction, the ground adjacent to excavations should be continuously monitored for cracks or
dips and other indications of movements and possible sloughing of the excavation walls. Such
monitoring is particularly critical in areas adjacent to existing structures and utilities.
6.4 Wet Weather Construction
General recommendations relative to earthwork performed in wet weather or in wet conditions
are presented below:
® Earthwork should be performed in small areas to minimize subgrade exposure to wet
weather. Excavation or the removal of unsuitable soil should be followed promptly
by the placement and compaction of clean structural fill. The size and type of
construction equipment used may have to be limited to prevent soil disturbance.
09-146 Storm Sewer Rpt Rev2.doc Page 6 PanGEO, Inc.
Geotechnical Engineering Report
Storm Sewer Improvements, 1205 — 12t" Avenue N, Edmonds, Washington
Revised February 19 2010
• During wet weather, the allowable fines content of the structural fill should be
reduced to no more than 10 percent by weight based on the portion passing 3/4 -inch
sieve. The fines should be non -plastic.
• The ground surface within the construction area should be graded to promote run-off
of surface water and to prevent the ponding of water.
• Bales of straw and/or geotextile silt fences should be strategically located to control
erosion and the movement of soil.
• Excavation slopes and soils stockpiled on site should also be covered with plastic
sheets.
7.0 UNCERTAINTY AND LIMITATIONS
We have prepared this report for use by the Gray & Osborne and the City of Edmonds.
Recommendations contained in this report are based on a site reconnaissance, a subsurface
exploration program, review of pertinent geologic publications, and our understanding of the
project. The study was performed using a mutually agreed-upon scope of work.
Variations in soil conditions may exist between the locations of the explorations and the actual
conditions underlying the site. The nature and extent of soil variations may not be evident until
construction occurs. If any soil conditions are encountered at the site that are different from
those described in this report, we should be notified immediately to review the applicability of
our recommendations. Additionally, we should also be notified to review the applicability of our
recommendations if there are any changes in the project scope.
The scope of our work does not include services related to construction safety precautions. Our
recommendations are not intended to direct the contractors' methods, techniques, sequences or
procedures, except as specifically described in our report for consideration in design.
Additionally, the scope of our work specifically excludes the assessment of environmental
characteristics, particularly those involving hazardous substances.
This report may be used only by the client and for the purposes stated, within a reasonable time
from its issuance. Land use, site conditions (both off and on-site), or other factors including
advances in our understanding of applied science, may change over time and could materially
affect our findings. Therefore, this report should not be relied upon after 24 months from its
issuance. PanGEO should be notified if the project is delayed by more than 24 months from the
date of this report so that we may review the applicability of our conclusions considering the
time lapse.
It is the client's responsibility to see that all parties to this project, including the designer,
contractor, subcontractors, etc., are made aware of this report in its entirety. The use of
09-146 Storm Sewer Rpt Rev2.doc page 7 PanGEO, Inc.
Geotechnical Engineering Report
Storm Sewer Improvements, 1205 — 12t11 Avenue N, Edmonds, Washington
Revised February 19 2010
information contained in this report for bidding purposes should be done at the contractor's
option and risk. Any party other than the client who wishes to use this report shall notify
PanGEO of such intended use and request permission to copy this report. Based on the intended
use of the report, PanGEO may require that additional work be performed and that an updated
report be reissued. Noncompliance with any of these requirements will release PanGEO from
any liability resulting from the use this report.
Within the limitation of scope, schedule and budget, PanGEO engages in the practice of
geotechnical engineering and endeavors to perform its services in accordance with generally
accepted professional principles and practices at the time the Report or its contents were
prepared. No warranty, express or implied, is made.
We appreciate the opportunity to be of service. Please feel free to contact our office with any
questions you have regarding this report.
Sincerely,
Michael H. Xue, P.E.
Senior Geotechnical Engineer
Siew L. Tan, P.E.
Principal Geotechnical Engineer
09-146 Stonn Se\Ver Rpt Revldoc Page 8 PanGEO, Inc•
Geotechnical Engineering Report
Storm Sewer Improvements, 1205 — 12t" Avenue N, Edmonds, Washington
Revised February 19, 2010
8.0 REFERENCES
Minard, J.P., 1983, Geology Map of The Edmonds East and Part of The Edmonds West
Quadrangles, Washington. USGS Miscellaneous Field Studies, MAP MF -1541, scale
1:24,000.
WSDOT, 2008, Standard Specifications for Road, Bridges, and Municipal Construction.
09-146 Storm Sewer Rpt Revldoc Page 9 PanGEO, Inc.
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� t � '
RELATIVE DENSITY / CONSISTENCY
SAND/GRAVEL
Fissured: Breaks along defined planes
SILT / CLAY
GW: Well -graded GRAVEL
SPT
Approx. Relative
..........................................................
SPT
Approx. Undrained Shear
Density
N -values
Density (%)
Cit
Consistency
y
N -values
Strength (psf)
Very Loose
<4
<15
: Very Soft
<2
<250
Loose
4 to 10
15.35
Soft
2 to 4
250.500
Med. Dense :
10 to 30
35.65
Med. Stiff
4 to 8
500.1000
Dense
30 to 50
65.85
Stiff
8 to 15
1000.2000
Very Dense
>50
85.100
: Very Stiff
15 to 30
2000.4000
......................................................
CH : Fat CLAY
......................................................
..........................-..................................
Hard
>30
>4000
UNIFIED SOIL CLASSIFICATION SYSTEM
MAJOR DIVISIONS GROUP DESCRIPTIONS
Fissured: Breaks along defined planes
�!
GW: Well -graded GRAVEL
Gravel GRAVEL (<5% fines)
Blocky: Angular soil lumps that resist breakdown
..........................................................
50% or more of the coarse :..................................
o
GP : Poorly -graded GRAVEL
.....:......................................................
fraction retained on the #4
sieve. l i GRAVEL (>12% fines)
Numerous: More than one per foot
GM : Silty GRAVEL
••11•••••••••••••••••••••••• ........................••••••
)for5%se
o12%symbofines.
GP•GM) for 5% to 12%fines.
Fine Sand: #40 to #200 sieve (0.42 to 0.074 mm)
GC:. Clayey GRAVEL
....................................................... .
...........................................................................
Silt 0.074 to 0.002 mm
SW i Well -graded SAND
Sand SAND (<5/° fines)
::•.•............................................................
Pocket Penetrometer
50% or more of the coarse
::..:..
SP : Poorly -graded SAND
.............................
fraction passing the #4 sieve.
Use dual symbols leg. SP -SM)
TV
............................................................
SM i Silty SAND
for 5% to 12% fines. SAND(>12%fines)
.................................................... I.......................
ISC
: Clayey SAND
....................................................... .
:
ML: SILT
Liquid Limit<50
.....:......................................................
CL : Lean SILT
.................................................. I.........
Silt and Clay
==
OL : Organic SILT or CLAY
50%or more passing #200 sieve
MH : Elastic SILT
:
Liquid Limit> 50
Non-standard penetration
......................................................
CH : Fat CLAY
......................................................
..........................-..................................
OH: Organic SILT or CLAY
..............................................................
HighlyOrganic Soils
Grab
PT : PEAT
Notes: 1. Soil exploration I� s contain material descriptions based on visual observation and field tests using a system
modified from the Umrorm Soil Classification System(USCS). Where necessary laboratory tests have been
conducted (as noted in the 'Other Tests" column), uniit descriptions may include a classification. Please refer to the
discussions in the report text for a more complete description of the subsurface conditions.
2. The graphic symbols given above are not inclusive of all symbols that may appear on the borehole logs.
Other symbols may be used where field observations indicated mixed soil constituents or dual constituent materials.
DESCRIPTIONS OF SOIL STRUCTURES
Layered: Units of material distinguished by color and/or
Fissured: Breaks along defined planes
composition from material units above and below
Slickensided: Fracture planes that are polished or glossy
Laminated: Layers of soil typically 0.05 to 1mm thick, max.1 cm
Blocky: Angular soil lumps that resist breakdown
Lens: Layer of soil that pinches out laterally
Disrupted: Soil that is broken and mixed
Interlayered: Alternating layers of differing soil material
Scattered: Less than one per foot
Pocket: Erratic, discontinuous deposit of limited extent
Numerous: More than one per foot
Homogeneous: Soil with uniform color and composition throughout
BCN: Angle between bedding plane and a plane
normal to core axis
COMPONENT DEFINITIONS
COMPONENT
SIZE / SIEVE RANGE
COMPONENT SIZE / SIEVE RANGE
Boulder:
> 12 inches
Sand
Cobbles:
3 to 12 inches
Coarse Sand: #4 to #10 sieve (4.5 to 2.0 mm)
Gravel
DD
Medium Sand: #10 to #40 sieve (2.0 to 0.42 mm)
Coarse Gravel::
3 to 3/4 inches
Fine Sand: #40 to #200 sieve (0.42 to 0.074 mm)
Fine Gravel:
3/4 inches to #4 sieve
Silt 0.074 to 0.002 mm
Perm
Permeability
Clay <0.002 mm
TEST SYMBOLS
for In Situ and Laboratory Tests
listed
in "Other Tests" column.
CBR
California Bearing Ratio
Comp
Compaction Tests
Con
Consolidation
DD
Dry Density
DS
Direct Shear
%F
Fines Content
GS
Grain Size
Perm
Permeability
PP
Pocket Penetrometer
R
R -value
SG
Specific Gravity
TV
Torvane
TXC
Triaxial Compression
UCC
Unconfined Compression
SYMBOLS
Sample/In Situ test types and intervals
2 -inch OD Split Spoon, SPT
(140 -Ib. hammer, 30" drop)
3.25 -inch OD Spilt Spoon
(300 -Ib hammer, 30" drop)
11115-1
Non-standard penetration
test (see boring log for details)
Thin wall (Shelby) tube
Grab
Rock core
®
Vane Shear
MONITORING
WELL
SZ
Groundwater Level at
time of drilling (ATD)
Static Groundwater Level
Cement/ Concrete Seal
Bentonite grout / seal
Silica sand backfill
Slotted tip
Slough
Bottom of Boring
MOISTURE CONTENT
Dry
Dusty, dry to the touch
Moist
Damp but no visible water
Wet
Visible free water
6
PanG
Terms and Symbols for'E
I N C O R P O R A T E D Boring and Test Pit Logs Figure A -1q
Phone: 206.262.0370
Project: Storm Sewer Improvements
Surface Elevation: 302.5'
Job Number: 09-146
Top of Casing Elev.: na
Location: Edmonds, Washington
Drilling Method: HSA - Acker Rig
Coordinates: Northing: , Easting:
Sampling Method: SPT - Cathead
N -Value
Z
C
U)
U)
p
PL Moisture LL
a)
�
F
a
E
MATERIAL DESCRIPTION
p�
U)
a
U)
m
a�
0
®RQD Recovery
0 50 100
0
5
PF
Approximately 1.5" Asphalt Concrete.
Loose to medium dense, brown -gray, slightly silty to silty SAND,
S-1
7
some gravel, trace charcoal, moist (Fill).
6
2
3
-becomes brown -dark brown, silty SAND, little gravel, trace charcoal,
loose, moist.
S-2
3
1
4
4
S3
8
6
29
Dense to very dense, gray, silty SAND, little gravel, moist (Till).
43
8
S-4
36
GS
41
Bottom of boring at about 9 feet below surface. Groundwater was not
encountered during drilling.
10
12
I
14
i
c
i
.........
.........
.........
.........
16
Completion Depth: 9.0ft
Remarks: Boring was drilled with a hand portable drill rig. Standard Penetration Test
Date Borehole Started: 11/4/09
(SPT) sampler driven with a 140 Ib. safety hammer operated with a rope and cathead
Date Borehole Completed: 11/4/09
mechanism.
Logged By: HMX
Drilling Company: CN Drilling
Pan G--"El@LOG OF TEST BORING BH -1
I N C O R P O R A T E D Figure A-2
Phone: 206.262.0370
The stratification lines represent approximate boundaries. The transition may be gradual. Sheet 1 Of 1
v
0
Project: Storm Sewer Improvements
Surface Elevation: 294.5'
Job Number: 09-146
Top of Casing Elev.: na
Location: Edmonds, Washington
Drilling Method: HSA - Acker Rig
Coordinates: Northing: , Easting:
Sampling Method: SPT - Cathead
N -Value
o(U
Z
T
c
(D
aa)
o
PL Moisture LL
o
F-
n
;
~
E
MATERIAL DESCRIPTION
-'
CL
0
m
>,
U
® RQD Recovery
c
m
O
0 50 100
0
2
Loose, brown, silty medium to coarse SAND, trace gravel, roots in
the upper 3", moist (Fill).
S-1
2
2
2
2
-grades with more gravel.
S-2
2
3
4
5
S-3
26
Very dense, gray, silty SAND, some gravel, moist (Till).
6
27
14
-becomes gray -brown, medium SAND with silt/slightly silty SAND,
g
dense, moist.
MEM!
S-4
19
27
1
WE
10
31
-Becomes gray, silty SAND with some gravel, very dense, moist.
S-5
50/6
Bottom of boring at about 11.0 feet below surface. Groundwater was
not encountered during drilling.
12-
-14-
.........
.........
16
Completion Depth: 11.5ft
Remarks: Boring was drilled with a hand portable drill rig. Standard Penetration Test
Date Borehole Started: 11/4/09
(SPT) sampler driven with a 140 Ib. safety hammer operated with a rope and cathead
Date Borehole Completed: 11/4/09
mechanism.
Logged By: HMX
Drilling Company: CN Drilling
RnGE@ LOG OF TEST BORING BH -2
'NC
Phone: 206.262.0370 ii
The stratification lines represent approximate boundaries. The transition may be gradual. Sheet 1 Of
Project: Storm Sewer Improvements
Surface Elevation: 270.5'
Job Number: 09-146
Top of Casing Elev.: na
Location: Edmonds, Washington
Drilling Method: HSA - Acker Rig
Coordinates: Northing: , Easting:
Sampling Method: SPT - Cathead
N -Value
o
Z
(D
T
c
CD
U)
ai
o
PL Moisture LL
-�
°'
2
~
E
MATERIAL DESCRIPTION
mr
CL
p
°
U)
a
U)
`n
m
a`)
O
>,
®RQD Recovery
0 50 100
0
2
'—'' `'
Approximately 4" of dark brown bark.
Loose, brown -dark brown, silty SAND, some gravel, moist (Fill).
S-1
2
2
2
3
-becomes brown -tan, silty SAND with some gravel, moist.
S-2
10
34
Dense to very dense, brown, silty SAND, trace to some gravel, moist
4
;
(Till).
27
-becomes brown -tan, silty gravelly SAND, very dense, very moist.
S-3
26
GS
6
50/4
S-4
X
50/6
-becomes gray, silty SAND, some gravel, very dense, moist.
8
Bottom of boring at about 8 feet below surface. Groundwater was not
encountered during drilling.
10
12
l
14
;
i
i
16
Completion Depth: 8.0ff
Remarks: Boring was drilled with a hand portable drill rig. Standard Penetration Test
Date Borehole Started: 11/4/09
(SPT) sampler driven with a 140 Ib. safety hammer operated with a rope and cathead
Date Borehole Completed: 11/4/09
mechanism.
Logged By: HMX
Drilling Company: CN Drilling
LOG OF TEST BORING BH -3
!RnGE8
I N C O R P O R A T E D Figure A-4
Phone: 206.262.0370
The stratification lines represent approximate boundaries. The transition may be gradual. Sheet 1 Of 1
U.S. SIEVE OPENING IN INCHES I U.S. SIEVE NUMBERS I HYDROMETER
6 4 3 2 1.5 1 1/23/8 3 4 6 810 1416 20 30 40 5060 100140200
100
90
80
70
I-
x
w 60
r
m
z 50
H
z
w
40
w
a
30
20--
10
0
100 10 1 0.1 0.01 0.0
GRAIN SIZE IN MILLIMETERS
)1 1
Specimen Identification Classification LL PL PI Cc Cu
® 131-1-1 @ 7.5 ft. Gray, silty SAND (SM)
M 131-1-3 @ 5.0 ft. Brown -tan, silty gravelly SAND (SM)
Specimen Identification D100 D60 D30 D10 %Gravel %Sand %Silt I %Clay
101 BH -1 7.5 19.05 0.209 0.081 3.7 68.5 27.9
MI BH -3 5.0 19.05 2.209 0.175 32.2 47.0 20.7
GRAIN SIZE DISTRIBUTION
PanGEOProject: Storm Sewer Improvements
1114c o :R P o R A T E D Job Number: 09-146 Figure
Phone: 26P .0370 Location: Edmonds, Washington B�1
COBBLES
GRAVEL
I SAND
SILT OR CLAY
coarse fine
I coarse I medium fine
)1 1
Specimen Identification Classification LL PL PI Cc Cu
® 131-1-1 @ 7.5 ft. Gray, silty SAND (SM)
M 131-1-3 @ 5.0 ft. Brown -tan, silty gravelly SAND (SM)
Specimen Identification D100 D60 D30 D10 %Gravel %Sand %Silt I %Clay
101 BH -1 7.5 19.05 0.209 0.081 3.7 68.5 27.9
MI BH -3 5.0 19.05 2.209 0.175 32.2 47.0 20.7
GRAIN SIZE DISTRIBUTION
PanGEOProject: Storm Sewer Improvements
1114c o :R P o R A T E D Job Number: 09-146 Figure
Phone: 26P .0370 Location: Edmonds, Washington B�1