hadfieldgeotech.pdfMarch 10, 2006
File No. 05-155
Mr. Carter Woollen, AIA
Woollen Studio He
5339 Ballard Avenue NW
Seattle, WA 98107
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C O R P O R A?■ O
Geotechnical a Earthquake
Engineering Consultants
Subject: Geotechnical Engineering Report
506 -- 6t" Avenue South, Edmonds, Washington 98020
Dear Mr. Woollen,
RECEIVED
APR I 1 £ 006
PERMIT COUNTER
As requested, PanGEO Inc. completed a geotechnical engineering study to assist you and
your designers with the design of the two new single family residences to be constructed
at 506 6th Avenue South. This study was performed in accordance with our mutually
agreed upon scope of work as outlined in our proposal dated September 6, 2005. Our
service scope included reviewing readily available geologic data, drilling three test
borings, and developing the conclusions and recommendations presented in this report.
PROJECT AND SITE DESCRIPTION
The site is located just southeast of downtown Edmonds, at the approximate location
shown in Figure 1. The site is currently vacant, although we understand that a single
family residence with a basement (finish floor elevation 131.5 feet) was removed from
the eastern portion of the site prior to our involvement. The property is bordered on the
south by Holly Drive, on the east and west by sinve-family residences, and on the north
by an apartment building and the cul-de-sac for 6 Avenue South. The site measures
approximately 100 feet in the north -south direction and approximately 120 feet in the
east -west direction.
Plate 1. Looking northeast from
southwest corner of site
The majority of the site slopes down to the west at
grades of about 10%, as shown on Figure 2. There is
an existing rockery along the west end of the property
with a maximum height on the order of 3 feet. We
understand that you plan to subdivide the lot and build
two single-family residences. Both houses will have
three floors, including a basement, and anticipated to
be conventional wood -frame structures.
3414 N.E. 55u' Street
Seattle, WA 98105
(206)262-0370
FAX (206) 262-0374
Mr. Carter Woollen
Hadfield Residence
March 10, 2006
The eastern (upslope) house will have a finish floor elevation of about 125.5 feet. With
the existing ground surface at about Elev. 138 feet, up to about 14 feet of excavation will
be needed along the east building line to facilitate the footing construction. Because the
new house will be setback about 12 feet from the east property line, limited space is
available for an open excavation. The western house will have its lowest floor at
Elevation 123 feet, approximately snatching the existing grade along the west property
line. Therefore, the amount of excavation for the west house is considered relatively
minor.
SUBSURFACE EXPLORATIONS
Three borings H-1 through BH -3 were drilled at the site on October 1 2
g CB g ) 0, 005 to
explore the subsurface conditions. The approximate boring locations are indicated on
Figure 2. The borings were drilled to depths of approximately 161/2 to 24 feet below the
existing ground surface, using a portable drill rig owned and operated by CN Drilling of
Seattle, WA. The drill rig was equipped with 4 -inch outside diameter hollow stem
augers. Soil samples were obtained from the borings at 2%2 -foot intervals using Standard
Penetration Test (SPT) sampling methods. SPT samples are obtained using a 2 -inch
outside diameter split -spoon sampler, driven into the soil a distance of 18 inches using a
140 -pound weight failing a distance of 30 inches. The number of blows required for each
6 -inch increment of sampler penetration was recorded. The number of blows required to
achieve the last 12 inches of sample penetration 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 soils.
An engineer from PanGEO was present during the field exploration to observe the
drilling, assist in sampling, and to describe and document the soil samples obtained from
the borings. The soil samples were described using the system outlined on Figure 3, and
summary logs are included as Figures 4 through 6.
SUBSURFACE CONDITIONS
According to mapping by Booth, Cox, Troost, and Shimel (Draft Geologic Map of Sno-
King Area, 2004), the site is underlain by Pre -Fraser Deposits. Our exploratory borings
advanced at the site appear to have encountered a different geologic sequence. The soil
conditions encountered in our explorations generally consisted of up to 12 feet loose to
medium dense sand fill overlying glacially medium dense to dense native outwash and
glacial till deposits. Descriptions of these soil units are discussed below and a
generalized subsurface profile is shown in Figure 7.
Unit I Fill — Fill was encountered in borings BH -1 and BH -2. The fill ranged from
about 9 foot thick in BH -1 to about 12 feet in BH -2. This unit consisted of loose to
medium dense sand with occasional roots. The composition and quality of fill may
vary significantly across the site.
05-155 Report.aoe Page 2 of 11 PanGEO, Inc.
Mr. Carter Woollen
Hadfield Residence
March 10, 2006
Unit 2 Outwash Sand — Medium dense to dense sand was encountered beneath the
fill in borings BH -1 and BH -2 and directly below the topsoil at a depth of 18 inches
in boring BH -3. This unit extended to a depth of 21 feet below the existing grade in
borings BH -1 and BH -3, and to the bottom of the boring in BH -2.
Unit 3 Glacial Till --- Very dense sandy silt was encountered below unit 2 in borings
BH -1 and BH -3. The top of Unit 3 was approximately 21 feet below existing grade.
Groundwater seepage was not encountered in any of the borings. It should be noted that
groundwater elevations may vary depending on the season, local subsurface conditions,
and other factors. Groundwater levels are normally highest during the winter and early
spring. Based on the subsurface stratigraphy, a seasonal perched groundwater table could
be present on top of the glacial till during the wet winter months.
CONCLUSIONS AND RECOWYTENDATIONS
GROUND MOTION FOR SEISMIC DESIGN
We understand that the 2003 IBC will be used for the project. Ground motion parameters
consistent with the IBC are provided below.
Recurrence Interval 25475 year
Site Class D
SS 1.22
S1 0.43
FA 1.01
Fv 1.57
SDs 0.82
SDI 0.45
Design PGA 0.33 (SDs/2.5)
The spectral response accelerations were obtained from the USGS Earthquake Hazards
Program website using the Interactive Deaggregation (2002) for the project latitude and
longitude.
-
FOOTING FOUNDATION
It is our opinion that conventional spread footings are appropriate for the proposed
addition project. The footing subgrade conditions are anticipated to vary across the site,
and may,consist of loose sandy fill and medium dense, native outwash sand. Where
loose fill is encountered, we recommend a one -foot overexcavation below the bottom of
the footing. The exposed subgrade should then be compacted to a dense and unyielding
condition. On site soil may then be placed on the compacted surface in two equal lifts
05-155 ReporLdoc Page 3 of 11 PanGEO, Inc.
Mr. Carter Woollen
Hadfield Residence
March 10, 2006
and compacted to a dense condition. Overexcavation is not needed when native outwash
sand is present at the footing subgrade.
Footings constructed as described above may be sized using an allowable bearing
pressure of 2,000 psf. For allowable stress design, the recommended allowable bearing
pressure may be increased by 1/3 for transient conditions such as wind and seismic
loadings. All footings should be founded a minimum depth of 18 inches below the
adjacent finish grade, or for interior footings, 12 inches below the floor slab. For this
project, we recommend that all footings should have minimum width of 24 inches.
Total and differential settlements are anticipated to be within tolerable limits for footings
designed and constructed as discussed above. Footing settlement under static loading
conditions are estimated to be less than about 1 -inch and differential settlement between
adjacent columns should be less than about !/z -inch. Most settlement will occur during
construction as loads are applied.
Lateral forces from wind or seismic loading may be resisted by the combination of
passive earth pressures acting against the embedded portions of the foundations and by
friction acting on the base of the foundations. Passive resistance values may be
determined using an equivalent fluid weight of 300 pounds per cubic foot (pcf). This
value includes a factor safety of at least 1.5 assuming that a properly compacted
structural fill will be placed adjacent to the sides of the footings. A coefficient friction of
0.4 may be used to determine the frictional resistance at the base of the footings. This
coefficient includes a factor safety of approximate 1.5.
All footing excavations should be trimmed neat and footing subgrades should be
carefully prepared. Any loose or softened soil should be removed from the footing
excavations. Footing excavations should be observed by PanGEO to confirm that the
exposed footing subgrade is consistent with the expected conditions and adequate to
support the design bearing pressure.
BASEMENT WALLS
Basement walls should be properly designed to resists the pressure exerted by the soils
behind the walls. Proper drainage provisions should also be provided behind the walls
such that groundwater will not accumulate behind the wails. Presented below are our
geotechnical recommendations for the design and construction of the basement walls.
Lateral Eartk Pressures — Basement walls may be designed for an equivalent fluid
pressure of 45 pcf We also recommend that a uniform lateral pressure of 7H psf be
used to account to seismic loading conditions, where "H" is the exposed wall height
in feet. The recommended lateral pressures assume that the backfill behind the wail
05-155 ReporLdoa Page 4 of 11 PanGEO, Inc.
Mr. Carter Woollen
Hadfield Residence
March 10, 2006
will consist of properly compacted structural fill, and adequate wall drainage
provisions are incorporated into the design and construction of the walls.
Surcharge — Surcharge loads, where present, should also be included in the design
of retaining walls. We recommend that a lateral load coefficient of 0.3 be used to
compute the lateral pressure on the wall face resulting from surcharge loads located
within a horizontal distance of one-half wall height.
Wall Footing — See the Footing Foundation section above
Lateral Resistance — See the Footing Foundation section above
Wall Drainage — As a minimum, for conventional walls that require backfill,
provision for permanent control of subsurface water should consist of a perforated
drainpipe behind and at the base of the wall footings, embedded in clean washed
drain rock or pea gravel. The drain rock should be wrapped in geotextile filter fabric
to limit the migration of fines from the native soils into the drain system. The
drainpipe should be graded to direct water away from the backfill and subgrade soils
and to a suitable outlet.
Wall Backfill — Wall backfill should consist of free draining granular soils. The
existing on-site soils may be used as wall backfill, provided that the on-site soils can
be properly moisture conditioned and compacted. All wall backfill should be placed
in loose, horizontal lifts less than 8 inches in thickness, and systematically
compacted to a dense and relatively unyielding condition. Within 5 feet of the walls,
we recommend using small equipment such as plate wackers for fill compaction, to
prevent damage to the concrete wall. In the area where the space is limited between
the wall and the face of excavation, pea gravel may be used without compaction.
Damp Proofing — All basement walls should be protected with a damp proofing
compound.
FLOOR SLABS
Conventional slab on grade construction may be used for the floor slabs. Prior to the slab
construction, we recommend that the exposed subgrade be compacted to a dense and
unyielding condition. We also recommend that interior slabs be constructed on a
minimum 4 -inch thick capillary break placed on the compacted subgrade.
The capillary break should consist of free -draining, crushed rock or well -graded gravel
compacted to a firm and unyielding condition. The capillary break material should have
no more than 10 percent passing the No. 4 sieve and less than 5 percent by weight of the
05-155 Report.aoo Page 5 of l 1 PanGEO, Inc.
Mr. Carter Woollen
Hadfield Residence
March 10, 2006
material passing the U.S. Standard No_ 100 sieve. We also recommend that a 10 -mil
polyethylene vapor barrier be placed below the slab.
Prior to placement of the capillary break, the adequacy of the exposed subgrade should be
verified by PanGEO. We also recommend that construction joints be incorporated into
the floor slab to control cracking.
ROCKERY
We understand that a series of short rockeries may be constructed for grade separation.
Although rockeries are typically used to retain cuts, it is our opinion that rockeries may
also be used to retain fill provided that the retained fill height is less than 5 feet, and the
backslope above the rockeries is no steeper than 411:1 V. In addition, any foundation
elements behind the rockeries should be placed sufficiently deep that the foundation
elements will be located beyond a IY2H:1V projection from the heel of the rockeries.
Construction of rockeries should be performed in accordance with Section 8-24 of the
2004 WSDOT Standard Specifications. For design purposes, the base rock should have a
minimum width equivalent to at least one-third the wall height, and gradually taper to a
minimum top width of 1 %z foot (i.e., two-man rock). Rocks smaller than 1'/2 -foot in
width should not be used for this project. The width is designated as the width of a single
rock as measured perpendicular to the face of the slope. The wall face should be inclined
no steeper than 6V:1 H, and the base rocks should be keyed in at least 1 foot below the
lowest adjacent grade.
All rockeries should be founded on relatively undisturbed native soils or properly
compacted structural fill. if soft compressible soils are encountered in the rockery
foundation soils, it may be necessary to remove and replace the soft soils to the depth
determined by the field engineer.
Rocks should be placed so that the contact seam between two adjacent rocks is not above
or below the vertical contact seam for the upper and lower courses (i.e. each rock should
overlap at least two different rocks in the course below). The long axis of each rock
should be placed perpendicular to the slope. The rock surfaces between individual
courses should be relatively flat, and should in no case slope downward away from the
wall face.
Rock quality is critical to rockery wall performance. Many rockery failures occur
because of degradation of poor -grade rocks under freeze -thaw and weathering conditions.
As a minimum, the rock used should meet the requirements outlined in Section 9.13.7(1)
of the 2004 edition of WSDOT/APWA Standard Specifications. The chinking material
for backfill should meet the requirements outlined in Section 9.13.7(2).
05-155 Repomdoc Page 6 of 11 PanGEO, Inc.
Mr. Carter Woollen
Hadfield Residence
March 10, 2006
TEmpoRARY ExcAVAnoN
We anticipate the excavation to encounter mostly loose to medium dense sand. For
p y
planning purposes, where space is available, we recommend that temporary excavations
over 4 feet deep be graded no steeper than IH:IV. We also recommend that heavy
construction equipment, building materials, excavated soil, and vehicular traffic should
not be allowed within a distance equal to 1/3 the slope height from the top of any
excavation. From the design information provided for our review, it appears that
sufficient space is available for a 1 H:1 V except a portion of east property line.
We understand that the eastern (upslope) residence will be located about 12 feet from the
east property line, and will have a finish floor elevation of 125.5 feet in the basement, and
the excavation is anticipated to extend to about Elevation 124 feet for the footings. The
maximum depth of excavation is anticipated to be about 14 feet to facilitate the footing
construction. Asa result, a 1 H:1 V excavation will encroach into the neighboring
property to the east. Therefore, it may be necessary to obtain an easement from the
neighboring property owner or excavation shoring will be required. If shoring will be
required, PanGEO will be available to provide additional input regarding appropriate
shoring types and design parameters.
Note that the neighboring house to the east is located about 17 feet away from the new
house. The excavating contractor should limit the amount of the excavation beyond the
edge of the new footing such that the neighboring footings will be located beyond a
1 HAV projection from the toe of the excavation.
Some groundwater seepage may be encountered during excavation. The amount of
groundwater may vary seasonally. If groundwater seepage is encountered, .we anticipate
that the use of drainage ditches and sump pumps will provide adequate construction
dewatering. During wet weather, runoff water should be prevented from entering
excavations.
We also recommend that all cut slopes be completely covered with plastic sheets to
prevent surficial erosion.
BASELINE SURVEY AND MON roRmG
Ground movements will occur as a result of excavation activities. As a result, conditions
of the adjacent structures and the ground surface elevation should be documented prior to
commencing earthwork to provide baseline data. As a minimum, we recommend that
existing adjacent residence be monitored during construction. This may include existing
crack surveys and photo -documentations. Optical survey points should be established on
existing building corners, and around the perimeter along the excavation as the
excavation proceeds. Both vertical and horizontal deformations should be measured
05-I55 Reportdoe Page 7 of 11 PanGEO, Inc.
Mr. Carter Woollen
Hadfield Residence
March 10, 2006
periodically during the construction process. We recommend that the monitoring be
performed by the contractor, and the results submitted to PanGEO for review. The
results of the monitoring will allow the design team to confirm design parameters, and for
the contractor to make adjustments if necessary.
WET EARTHWORK RECOMMENDATIONS
Given that the site soils can be moisture sensitive, it may be more economical to perform
the earthwork in the drier summer months. However, if earthwork will be conducted in
wet weather conditions, certain steps should be taken to mitigate the impacts of the
weather on the site conditions. 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.
• During wet weather, the allowable fines content of the structural fill should be
reduced to no more than 5 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. As a minimum, erosion control
measures should be installed along the east property boundaries.
• Excavation slopes and soils stockpiled on site should also be covered with
plastic sheets.
SURFACE DRAINAGE AND EROSxON CONTROL
Surface runoff can be controlled during construction by careful grading practices.
Typically, this includes the construction of shallow, upgrade perimeter ditches or low
earthen berms to collect runoff and prevent water from entering the excavation. All
collected water should be directed under control to a positive and permanent discharge
system such as a storm sewer.
os-lss Report.doc Page 8 of 11 PanGEO, hie.
Mr. Carter Woollen
Hadfield Residence
March 10, 2006
Temporary erosion control measures should be provided and maintained during
construction. Erosion control should consist of bales of straw and/or geotextile silt fences
strategically located to control erosion and the movement of soil. As a minimum, erosion
control measures should be installed along the south and west property boundaries. In
addition, filter "socks" should be installed in nearby catch basins and cleaned or replaced
periodically. The socks should be inspected after heavy rains. Efforts should be made to
prevent or at least limit the amount of soil material that is tracked off site on construction
vehicles. Temporary erosion control is especially critical when site grading activities
occur during wet weather periods.
Permanent control of surface water should be incorporated in the final grading design.
Adequate surface gradients and drainage systems should be incorporated into the design
such that surface runoff is directed away from structures.
ADDITIONAL SERVICES
To confirm that our recommendations are properly incorporated into the design and
construction of the proposed construction, PanGEO should be retained to conduct a
review of the final project plans and specifications, and to monitor the construction of
geotechnical elements. PanGEO can provide you a cost estimate for construction
monitoring services on a later date.
We anticipate that the following additional services may be required:
• Review final project plans and specifications
• Verify implementation of erosion control measures
• Evaluate and confirm the stability of temporary excavation slopes
• Verify adequacy of footing subgrade
• Verify the adequacy of subsurface drainage installation
• Confirm the adequacy of the compaction of structural backfill
• Other consultation as may be required during construction
Modifications to our recommendations presented in this report may be necessary, based
on the actual conditions encountered during construction.
LEVIITATIONS
We have prepared this report for use by Joel and Dana Hadfield and their project team.
Recommendations contained in this report are based on a site reconnaissance, a
subsurface exploration program, review of pertinent subsurface information, and our
05-155 Report.aoc Page 9 of 11 PanGEO, Inc.
Mr. Carter Woollen
Hadfield Residence
March 10, 2006
understanding of the project. The study was performed using a mutually agreed-upon
scope of work.
Variations in soil conditions may exist at locations away from 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. We are not mold consultants nor are our recommendations to be interpreted
as being preventative of mold development. A mold specialist should be consulted for all
mold -related issues.
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
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 for 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.
os-iss Report.aoc Page 10 of 1 I PanGEO, Inc.
Mr. Carter Woollen
Hadfield Residence
March 10, 2006
We trust that the information presented herein meets your need at this time. If you have
any questions, please do not hesitate to contact our office.
Sincerely,
►cls In, 7OD b
EXPIRES 10111 Z/ZDV
Siew L. Tan, P.E.
Principal Geotechnical Engineer
Attachments:
Figure I
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
05-155 Repomdoc
Vicinity Map
Site and Exploration Plan
Terms and Symbols for Boring and Test Pit Logs
Log of Test Boring BH -I
Log of Test Boring BH -2
Log of Test Boring BH -3
Generalized Profile, Section A
.Page 11 of 11 PanGEO, Inc.
Approx. Scale: 1" =112 mile
RanI Hadfield Residence
GE&I506 P Avenue S
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RELATIVE DENSITY / CONSISTENCY
SAND / GRAVEL
Fissured: Breaks along defined planes
SILT / CLAY
Density
SPT
Approx. Relative
Consistency
SPT
Approx, Undrained Shear
GP c Poorly�raded GRAVEL
N -values
Density (%)
.....;......................................................
GM t SiltyGRAVEL
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
500.1004
Dense
30 to 50
65-85
Stiff
8 to 15
1040.2000
Very Dense
>50
85.100
Very Stiff
15 to 30
2040.4000
OH: Organic SILT or CLAY
.............................................................
Highly Organic Soils
Hard
>30
>4000
UNIFIED SOIL CLASSIFICATION SYSTEM
MAJOR DIVISIONS GROUP DESCRIPTIONS
Fissured: Breaks along defined planes
•�
GW: Well -graded GRAVEL
Gravel GRAVEL {<5% foes}
Blocky: Angular soil lumps that resist breakdown
.....:......................................................
50% or more of the coarse :.................I................
•�
GP c Poorly�raded GRAVEL
fraction retained on the #4 ;
sieve. Use dual symbols (eg.
Numerous: More than one per foot
.....;......................................................
GM t SiltyGRAVEL
GRAVEL (>12% fines) GP-GM)for 5%to 12% fines. j
......................................................................
Fine Sand: 440 to #200 sieve (0.42 to 0.074 mm)
GC : Clayey GRAVEL
314 inches to #4 sieve
...
..... _................................. 6...................
SW: Well -graded SAND
Sand SAND (<5% )
5/°fines
50% or moreotthecoarse:...................................�.,:...
;::
.......,�-
..
SP Poorl raded SAND
:.
fraction passing the #4 sieve.
Use dualsymbols a SP-SN)
N i
• ��.:.
' r s
......................................................
SM Silty SAND.
for 5%to19 fines.SAND (>12%fifines)
......................................................................
:.::......,..•.......•
...........................................
SC ` Clayey SAND
TXC
Triaxial Compression
ML c SILT
Liquid Limit < 50
CL : Lean SILT
Silt and Clay
-
_
............................................................
OL c Organic SILT or CLAY
....
50%or more passing #200 sieve
-inch OD Split Spoon, SPT
._...:......................................................
MH :........................... Elastic SILT
Liquid Limit> 50
(140-1b. hammer, 30" drop)
CH : Fat CLAY
......................................................................
OH: Organic SILT or CLAY
.............................................................
Highly Organic Soils
PT i PEAT
Notes: 1. Soil exploration lo ggs contain material descriptions based on visual observation and field tests us'ng a system
modified from the Uniform Soil Classification System (USCS). Where necessary laboratory.tests have been
conducted (as noted in the "Other Tests" column), unit 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 constiluent materials.
DESCRIPTIONS OF SOIL STRUCTURES
Layered: Units ofrpaterial 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 imm 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
Fine Sand: 440 to #200 sieve (0.42 to 0.074 mm)
normal to core axis
COMPONENT DEFINITIONS
COMPONENT
SIZE / SIEVE RANGE
COMPONENT SIZE I 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:
i 3 to 3/4 inches
Fine Sand: 440 to #200 sieve (0.42 to 0.074 mm)
Fine Gravel:
314 inches to #4 sieve
Silt 0.074 to 0.002 mm
Penn
Permeability
Clay <0.002 mm
J
PmGE@Terms and Symbols for
a r N c o a r a re a T E n Boring and Test Pit Logs
Phone: 206.262.0370
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
Penn
Permeability
PP
Pocket Penetrometer
R
R -value
SG
Specific Gravity
TV
Torvane
TXC
Triaxial Compression
UCC
Unconfined Compression
SYMBOLS
Samplefin
Situ test types and intervals
®2
-inch OD Split Spoon, SPT
(140-1b. hammer, 30" drop)
e3.25
-inch OD Spilt Spoon
(3004b hammer, 30" drop)
Non-standard penetration
test (see boring log for details)
Thin wall (Shelby) tube
Grab
Rock core
®
Vane Shear
MONITORING WELL
5Z
Groundwater Level at
time of drilling (ATL))
1
Static Groundwater Level
Cement! Concrete Seal
Bentonite grout I seal
Silica sand backfill
Slotted fip
Slough
Bottom of Boring
MOISTURE CONTENT
Dry
Dusty, dry to the touch
Moist
Damp but no visible water
Wet
Visible free water
Figure 3
0
x
m
m
0
0
J
Project: Hadfield Residence
Surface Elevation: -138
Job Number: 05-155
Top of Casing Elev.:
Location: Seattle, Washington
Drilling Method: Hollow Stem Auger
Coordinates: Northing:, Easting
Sampling Method: SPT
N -Value A
o
CL
t-
>`
co
ai
a
PL Moisture LL
n
a
y
�
E
MATERIAL DESCRIPTION
(D
n
E
M
E
3
m
>,
® RQD Recovery
c4
O
M.
0
0 50
S-1
1
2
Medum dense, reddish brown, silty SAND with gravel, dry to moist,
9
occasional roots (TOPSOILIFILL).
Loose to medium dense, brown, SAND, dry to moist, with occasional
2
roots. (PILL).
S-2
2
3
5
3
S-3
3
5
5
S-4
B
- numerous roots noted in sampler tip.
10
Medium dense to dense, grayish brown SAND with occasional gravel,
FEA
S-5
6
s
moist to very moist. (OUfWASH).
10
6
S-6
10
12
15
8
S-7
14
18
20
8
S-8
15
25
Verydense, grayish brown sandy SILT with gravel, moist,
heterogenous texture. (GLACIAL TILL).
S-9
21
5015
>
Bottom of boring at 23.5 ft. No groundwater encountered during
drilling.
25
30
Completion Depth: 23.4ft
Remarks: Standard Penetration Test (SPT) sampler driven with a 140 Ib. safety hammer.
Date Borehole Started: 10/10/05
Hammer operated with an rope and cathead mechanism. No groundwater encountered
Date Borehole Completed: 10/10/05
during drilling.
Logged By: TEA
Drilling Company: CN Drilling
PcmGE1@ LOG OF TEST BORING 131-1-1
INcaaP0RATE.O Figure
Phone. 206.262.0370
The stratification lines represent approximate boundaries. The transition may be gradual.
Sheet 1 of 1
cc
C
C
C:
C
C
Z
4
Project: Hadfield Residence
Surface Elevation: -128
Job Number: 05-155
Top of Casing Elev.:
Location: Seattle, Washington
Drilling Method: Hollow Stem Auger
Coordinates: Northing: , Easting:
Sampling Method: SPT
N
N -Value A
$
Z
CL
CD
a)
p
PL Moisture LL
C
Q
a
n
MATERIAL DESCRIPTION
m
�
® RQD Recovery
CD
�
0
0 50 100
S-1
Loose, brown, silty SAND with gravel, dry to moist, numerous roots
2
2
,(TOPSOIL).
Medium dense, brown, SAND, dry to moist. (FILL).
3
S-2
6
7
5
6
S-3
8
10
5
S-4
7
5law
10
3
S-5
6
5
- numerous roots noted in sampler tip.
Medium dense, grayish brown SAND, moist to very moist.
S-6
7
7
:.
(OUTWASH).
12
15
6
S-7
10
15
Bottom of boring at 16.5 ft. No groundwater encountered during
drilling-
rilling_20253
20-
25-
3
Completion Depth: 16.5ft
Remarks: Standard Penetration Test (SPT) sampler driven with a 940 Ib. safety hammer.
Date Borehole Started: 10/10/05
Hammer operated with an rope and cathead mechanism. No groundwater encountered
Date Borehole Completed: 10/10/05
during drilling.
Logged By: TEA
Drilling Company: CN Ddlling
LOG OF TEST BORING 131-1-2
F�LnGE@
' N C 0 R° Q N A T E° Figure 5
Phone: 206.262.0370
The stratification lines represent approximate boundaries. The transition may be gradual. Sheet 1 of 1
u
c
x
LL
a
LLC
Project: Hadfield Residence
Surface Elevation: —137
Job Number: 05-155
Top of Casing Elev.:
Location: Seattle, Washington
Drilling Method: Hollow Stem Auger
Coordinates: Northing: , Easting:
Sampling Method: SPT
c
N -Value A
p
Z
a�
a
(Q
a)
o
PL Moisture LL
o
CL
n
~
E
MATERIAL DESCRIPTION
o
E
M
rn
E
CU
W
3
m
p
>'
® RQD Recovery
0
0 50 100
5-1
1
Loose, reddish brown, silty SAND with gravel, dry to moist, numerous
2 2
roots (TOPSOIUFILL).
Medium dense to dense, grayish brown SAND with occasional gravel,
3
moist to very moist. (OUTWASH).
S-2
7
9
5
7
S-3
17
24
6
S-4
X
10
19
10
7
S-5
10
13
7
S-'
6
X
.11
16
15
7
S-7
18
19
20-
17
5016
:»
Very dense, grayish brown sandy SILT with gravel, moist,
heterogenous texture. (GLACIAL TILL).
27
S-8
33
50
Bottom of boring at 24 ft. No groundwater encountered during drilling.
25-
-30
Completion Depth: 24.Oft
Remarks: Standard Penetration Test (SPT) sampler driven with a 140 Ib. safety hammer.
Date Borehole Started: 10110/05
Hammer operated with an rope and cathead mechanism. No groundwater encountered
Date Borehole Completed: 10/10/05
during drilling.
Logged By: TEA
Drilling Company: CN Drilling
PanGE@ LOG OF TEST BORING 131-1-3
1 N L 0 6 P O N A T E D Figure r
F
Phone: 2D6.262.0370r g V
i ne sirauricavon ones represent approximate boundaries. The transition may be gradual. Sheet 1 of 1
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