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SUBSURFACE EXPLORATION AND
GEOTECHNICAL ENGINEERING REPORT
1
GOOD CHEVROLET PROPERTY
RENTON, WASHINGTON
PREPARED FOR
Le William Walker & Associates
1
PROJECT NO. G95190A
1
OCTOBER 1995
/MASSOCIATED
EARTH
A&M' SCIENCES, INC
911 -5th Avenue,Suite 100 724-Ericksen Ave.NE,Suite 204
Kirkland,Washington 98033 Bainbridge Island,WA98110
(206)827-7701 (206)780-9370
SUBSURFACE EXPLORATION AND
GEOTECHNICAL ENGINEERING REPORT
' GOOD CHEVROLET PROPERTY
RENTON, WASHINGTON
October 13, 1995
Project No. G95190A
I. PROJECT AND SITE CONDITIONS
1.0 INTRODUCTION
This report resents the results of our subsurface exploration and eotechnical engineering stud
P P P g g g Y
' for the construction of the Good Chevrolet Dealership structure in Renton, Washington. The
proposed building location and approximate locations of the explorations accomplished for this
study are presented on the Site and Exploration Plan, Figure 1. In the event that any changes
t in the nature, design or location of the structure are planned, the conclusions and
recommendations contained in this report should be reviewed and modified, or verified, as
necessary.
1.1 Purpose and Scope
' The purpose of this study was to provide subsurface data to be utilized in the design and
development of the above mentioned project. Our study included drilling test borings and
performing geologic studies to assess the type, thickness, distribution and physical properties of
the subsurface sediments and shallow ground water conditions. Engineering studies were also
conducted to determine the type of suitable foundation, allowable bearing pressures, anticipated
settlements, floor support recommendations, drainage considerations, and pavement
' recommendations. A liquefaction hazard evaluation was also completed. This report
summarizes our current field work and offers development recommendations based on our
present understanding of the project.
' 1.2 Authorization
' Written authorization to proceed with this study was granted by Mr. William Walker of William
Walker & Associates in a proposal dated August 3, 1995. This report has been prepared for the
exclusive use of William Walker & Associates, and their agents, for specific application to this
project. Within the limitations of scope, schedule and budget, our services have been performed
in accordance with generally accepted geotechnical engineering and engineering geology
' practices in effect in this area at the time odr report was prepared. No other warranty,
expressed or implied is made. Our observations, findings, and opinions are a means to identify
and reduce the inherent risks to the owner.
' 2.0 PROJECT AND SITE DESCRIPTION
' This report was completed with an understanding of the project based on a site plan prepared
by William Walker & Associates, dated March 29, 1995. The site was located within a
residential and commercial area in Renton, Washington. The property bordered I-405 to the
' south, Lind Avenue SW to the west, SW Grady Way to the north, and Maple Avenue SW to the
east. SW 12th Street and SW 13th Street both crossed the central part of the site in an
approximate east-west direction. The subject property was a combination of several residential
' and business parcels and measured about 700 feet north-south by about 350 feet east-west, less
a 160 foot by 130 foot parcel in the northeast portion of the property.
' Existing residential homes, apartments, and office buildings were present in the northern one
third of the site, north of SW 12th Street. This portion of the site contained a few residential
' lawns and paved parking areas that served the apartments and offices. The southern two thirds
of the property contained a few abandoned homes to the south of SW 12th and along SW 13th
Street. The southern two thirds of the parcel was generally overgrown with domestic tress,
' shrubs, grasses and blackberries.
The overall combined parcel was relatively flat but a steep slope (with a gradient of 68 percent
' over a vertical height of 24 feet) was present off-site but adjacent to the southwest corner of the
site. This slope was part of the roadway embankment where Lind Avenue SW went up a fill
slope to cross I-405.
' Present plans indicate that an approximate 28,000 square foot dealership structure will be
constructed at the site. It is our understanding that the existing homes, apartments and office
structures will be demolished prior to construction, and that SW 13th Street will be abandoned.
The apartments on the northwest corner of SW 12th and Maple Avenue were not within the
combined properties and apparently will remain. Construction details were not available at the
time of this report but we understand that a metal building will be used with a slab-on-grade
floor. Finished floor grades are anticipated to be near the existing site grade. The proposed
new structure will be located in the south central portion of the combined property. See Figure
' 1, Site and Exploration Plan.
3.0 SUBSURFACE EXPLORATION
Our field study included drilling a series of exploration borings to gain subsurface information
' about the site. The exploration borings were completed by advancing a 3-3/8 inch inside-
diameter, hollow-stem auger with a truck-mounted drill rig. During the drilling process,
' samples were obtained at 5 foot depth intervals in the area beneath the proposed structure and
at 2-1/2 foot intervals beneath the proposed parking areas. The borings were continuously
observed and logged by a field geologist from our firm. The summary exploration logs attached
' to this report are based on the field logs, drilling action, and inspection of the samples secured.
Disturbed but representative samples were obtained from the boreholes by using the Standard
' Penetration Test procedure in accordance with ASTM:D 1586. This test and sampling method
consists of driving a standard 2 inch outside-diameter split barrel sampler a distance of 18 inches
' 2
' into the soil with a 140 pound hammer free-falling a distance of 30 inches. The number of
blows for each 6 inch interval is recorded and the number of blows required to drive the sampler
' the final 12 inches is known as the Standard Penetration Resistance ("N") or blow count. If a
total of 50 is recorded within one, 6 inch interval, the blow count is recorded as 50 blows for
the number of inches of penetration. The resistance, or N-value, provides a measure of the
relative density of granular soils or the relative consistency of cohesive soils; these values are
plotted on the attached boring logs.
' The samples obtained from the split barrel sampler were classified in the field and representative
portions placed in water-tight containers. The samples were then transported to our laboratory
' for further visual classification and laboratory testing, as necessary. The various types of
sediments encountered, as well as the depths where characteristics of the sediments changed, are
indicated on the exploration logs. The depths indicated on the logs where conditions changed
may represent gradational variations between sediment types in the field. If changes occurred
between sample intervals in our borings, they were interpreted. Our explorations were located
in the field by measuring from known site features shown on the above mentioned site plan by
' William Walker & Associates.
Because of the nature of exploratory work below ground, extrapolation of subsurface conditions
between field explorations is necessary. It should be noted that differing subsurface conditions
may sometimes be present due to the random nature of deposition and the alteration of
topography by past grading and/or filling. The nature and extent of any variations between the
' field explorations may not become fully evident until construction. If variations are observed
at that time, it may be necessary to re-evaluate specific recommendations in this report and make
appropriate changes.
4.0 SUBSURFACE CONDITIONS
Subsurface conditions at the project site were inferred from the field explorations accomplished
for this study and visual reconnaissance of the site. As shown on the summary logs, the
' exploration borings encountered minor amounts of fill across the site that was underlain by
alluvial sand and silt (river deposits). The stratigraphy is described in the following section,
followed by our observations about the hydrology of the site.
' 4.1 Strati rah�v soils�
' Minor amounts of fill soils (material not naturally placed) was identified in EB-1, EB-3, EB-4,
and EB-5. The fill consisted of soft to stiff, damp, dark gray and brown, gravelly sandy silt
with crushed rock, glass fragments, and organics. The fill extended from the surface to depths
ranging from 1 foot in EB-1 and EB-3 and 1-1/2 feet in EB-5 to a depth of 3 feet in EB-4. In
EB-7 a 3 inch thickness of asphalt was encountered at the surface. The fill encountered in the
borings was relatively thin and widely scattered, but we would expect that significant thickness
of fill could be present in areas around old utility trenches, septic drain fields, or other disturbed
areas. Geotechnical engineering considerations regarding the fill should assume low strength
' properties and variable permeabilities.
3
Underlying the fill, and at the surface where the fill was absent, the natural soils consisted of
two units. An upper unit encountered in all seven borings consisted of damp, yellow brown to
dark brown, mottled, silt, sandy silt, and silty fine sand to fine sand with scattered gravel.
Locally, in EB-6, clayey silt was encountered. The upper unit extended from the surface (or
beneath the surficial fill) to depths of 3 feet in EB-4, 3-1/2 feet in EB-2, 6 feet in EB-3, and 8
' feet in EB-1. This unit extended below the 6-1/2 foot termination depths of EB-5, EB-6 and
EB-7.
' In EB-1, EB-2, EB-3, and EB-4, a brown to gray, fine to medium sand to sandy gravel with
scattered wood debris and local thin silt lenses was encountered beneath the upper unit. The
lower unit extended to below the 34 foot termination depths of both EB-1 and EB-2 and the
' 6-1/2 foot termination depths of EB-3 and EB-4. Loose sediments were encountered in samples
driven at a depth of 7-1/2 to 9 feet in EB-1, 12-1/2 to 14 feet in EB-2, and from 22-1/2 to 24
feet in both EB-1 and EB-2.
Both the upper and lower units are interpreted to represent geologically
pp rp p g g y recent alluvial sediments
' deposited by the ancestral Green/Black Rivers as the valley filled in. The lower unit reflects
deposition in a higher energy depositional environment near the stream channel, where the upper
unit is a low energy depositional environment typical of overbank deposits.
' 4.2 H, d�rolny
' No surface water was noted at the site during our field investigation. What is interpreted as a
regional water table was encountered at a depth of 10-1/2 feet in EB-2 and a depth of 12-1/2 feet
in EB-1. The water table is interpreted to lie at the same elevation in both borings and the
' difference in the depth at which it was encountered is attributed to differences in elevation of
the borings. Fluctuations in the elevation of the water table are expected to occur with seasonal
variations in rainfall. During the late winter months we would expect the water table to be
' several feet higher than during the time of our field study. Also, since the uppermost soils are
primarily fine grained in nature, we would anticipate areas of standing water to be encountered
following periods of rain.
' 4
' October 13, 1995
Project No. G95190A
II. DESIGN RECOMMENDATIONS
5.0 INTRODUCTION
' Our exploration indicates that, from a geotechnical standpoint, the parcel is suitable for the
proposed development provided that the geotechnical recommendations contained herein are
' properly utilized in the design and construction of this project. As noted on the field logs, our
exploration borings encountered loose sediments within the lower fine to medium sand unit in
samples at depths of 7-1/2 to 9 feet, 12-1/2 to 14 feet, and from 22-1/2 to 24 feet below the
' surface. Based on our analysis the lowermost zone is considered susceptible to liquefaction and
could cause settlement of a conventional shallow foundation during and after a seismic event.
' In addition, the zone encountered in EB-1, at a depth of 7-1/2 to 9 feet, is a weak zone that is
potentially compressible and not well suited for foundation support.
' Underlying the loose and liquefiable zones, at a depth of about 26 to 28 feet, both EB-1 and EB-
2 encountered dense, sandy gravel sediments that are considered a suitable foundation bearing
stratum. The depth to this bearing stratum will require that a deep foundation system be used
' to support the proposed structure. We recommend that augercast piles bearing within the dense
gravel be used for foundation support. Recommendations for augercast piles are presented in
the Foundations section of this report.
6.0 SITE PREPARATION
Site preparation of the proposed building and paved areas will require the demolition of the
existing structures and removal or relocation of underground utilities, if they are under a
' proposed building footprint. The debris from this operation should be taken to an offsite
disposal area and the resulting depressions should be replaced with structural fill. In the areas
away from existing structures/utilities, site preparation will require the removal of all trees,
brush, debris and any other deleterious material. The upper organic topsoil should be removed
and the remaining roots grubbed. Existing septic tank(s) or underground storage tanks (if
present) should be removed if they occur beneath the proposed new building footprint, and
' replaced with structural fill. All other areas where loose surficial soils exist should be
considered as fill and this material should either be removed and replaced with structural fill or
recompacted. Since the density of soils is variable, random soft/loose pockets may exist and the
' depth and extent of stripping can best be determined in the field by the field engineer.
' We have no knowledge of any underground storage tanks (USTs) on the site, and the removal
of non-leaking, residential USTs is not currently regulated by the City of Renton. However, if
tanks are discovered on the site and leakage is found, cleanup of contaminated soil is regulated,
and additional cleanup/disposal costs and time delays can be incurred. To avoid potential
construction delays, we would recommend the removal of all known USTs prior to construction.
' 5
' Associated Earth Sciences, Inc. can assist with determining if contaminated soil exists at the time
of UST removal. The resulting depressions should be backfilled with structural fill as discussed
' under the Structural Fill section.
Pavement subgrade preparation should be completed in accordance with the Pavement
' Recommendations section of this report.
7.0 STRUCTURAL FILL
To reduce the potential for pavement or slab settlement, it is essential that utility trenches and/or
' other excavations be backfilled with structural fill prior to building or pavement construction.
All references to structural fill in this report refer to subgrade preparation, fill type, placement
and compaction of materials as discussed in this section.
Within utility trenches, the depth of overexcavation will vary depending on location and depth
' of the utility. After overexcavation/stripping has been performed to the satisfaction of the
geotechnical engineer/engineering geologist, the upper 12 inches of exposed ground should be
recompacted to 90 percent of the Modified Proctor Maximum Density using ASTM:D 1557 as
' the standard. If the subgrade contains too much moisture, adequate recompaction may be
difficult or impossible to obtain, and further excavation and drainage installation may be required
before structural fill can be placed.
' After recompaction of the exposed ground is tested and approved, a structural fill may be placed
to attain desired grades. Structural fill is defined as non-organic soil, acceptable to the
' geotechnical engineer, placed in maximum 8 inch loose, horizontal lifts with each lift being
compacted to a minimum of 95 percent of the Modified Proctor Maximum Density using
ASTM:D 1557 as the standard.
' The contractor should note that any proposed fill soils must be evaluated by Associated Earth
Sciences, Inc. prior to their use in fills. This would require that we have a sample of the
' material 48 hours in advance to perform a Proctor test and determine its field compaction
standard. Soils in which the amount of fine-grained material (smaller than No. 200 sieve) is
greater than approximately 5 percent (measured on the minus No. 4 sieve size) should be
' considered moisture-sensitive. Use of moisture-sensitive soil in structural fills should be limited
to favorable dry weather conditions. In addition, construction equipment traversing the site
when the soils are wet can cause considerable disturbance. If fill is placed during wet weather
' or if proper compaction cannot be obtained, a select import material consisting of a clean, free-
draining gravel and/or sand should be used. Free-draining fill consists of non-organic soil with
the amount of fine-grained material limited to 5 percent by weight when measured on the minus
' No. 4 sieve fraction.
' It should be noted that the upper sediments on the site are generally fine grained and extremely
moisture sensitive. As such, they should not be utilized for structural fill.
' A representative from our firm should inspect the stripped subgrade and be present during
placement of structural fill to observe the work and perform a representative number of in-place
' 6
' density tests. In this way, the adequacy of the earthwork may be evaluated as filling progresses
and any problem areas may be corrected at that time.
' 8.0 LIQUEFACTION EVALUATION
' Samples were retrieved at 5 foot depth intervals from EB-1 and EB-2 and returned to Associated
Earth Sciences, Inc.'s laboratory for further analysis. Samples below the existing or potential
water table depth were examined to determine which were potentially liquefiable, based on their
' density and gradation characteristics. Those samples that were deemed to be potentially
liquefiable were then subjected to sieve analyses to determine their grain size distribution. The
results of the sieve analyses are attached. The laboratory and boring data were then used to
' calculate the potential for soil liquefaction during a strong earthquake. For this analysis, a
horizontal seismic acceleration of 0.2g was used as the design earthquake loading.
' Based on the above analysis, it was determined that at least one zone of soil with a high
likelihood of liquefaction exists beneath the subject site at a depth of 21 to 26 feet deep.
Although this zone was not of extensive thickness, it is our opinion that there is a potential for
' relatively large ground deformations if this zone were to liquefy, that could result in extensive
damage to the proposed structure, if not mitigated.
9.0 FOUNDATIONS
' With the above findings, it is our recommendation that the foundation for the dealership
structure be constructed on piles that extend through the weak and liquefiable zones into the
' underlying dense, sandy gravel stratum. Due to the nature of the overlying soils (variable
density), it may be difficult to drive timber piles on this site. Therefore, we recommend that
auger cast-in-place concrete piles be utilized for foundation support.
9.1 Augercast Piles
' Auger cast-in-place (augercast) piles should penetrate 5 feet into the dense gravel layer that was
encountered at the boring locations at a depth of about 26 feet below the ground surface. The
total pile depth below the existing ground surface would be about 30 to 32 feet. Augercast piles
' should be designed to resist the loads specified in the following table.
AUGERCAST PILE ALLOWABLE CAPACITY
Augercast Pile Diameter Penetration Depth* Allowable Capacity per Pile
' (Tons)
14" 5 10
' 16" 5' 13
18" 5' 15
' * Below depth 26 feet
1
' Allowable design loads may be increased by one third for short term wind or seismic loading.
Anticipated settlements of pile supported structures will generally be on the order of one-half
' inch.
9.2 Pile Inspections
' The actual total length of each pile may be adjusted in the field based on required capacity and
q P Y
conditions encountered during drilling. Since completion of the pile takes place below ground,
' the judgment and experience of the geotechnical engineer or his field representative must be used
as a basis for determining the required penetration and acceptability of each pile. Consequently,
' use of the presented pile capacities in the design requires that all piles be inspected by a qualified
geotechnical engineer or engineering geologist from our firm who can interpret and collect the
installation data and examine the contractors operations. Associated Earth Sciences, Inc., acting
' as the owner's field representative, would determine the required lengths of the piers and keep
records of pertinent installation data. A final summary report would then be distributed,
following completion of pile installation.
10.0 FLOOR SUPPORT
' A slab-on-grade floor may be used over structural fill, medium dense natural soils or
recompacted natural soils. If placed over recompacted soil, the upper 12 inches of subgrade
must be compacted to a minimum of 92 percent of the modified Proctor maximum density as
determined by ASTM:D 1557. A polyethylene plastic vapor barrier should be used under floors
likely to receive an impermeable floor finish or where passage of water vapor through the floor
' is undesirable. Based on American Concrete Institute recommendations, we suggest placing a
two to three inch layer of clean sand over the vapor barrier to protect the vapor barrier and to
allow some moisture loss through the bottom of the slab to reduce warping in the curing process.
Sand should be used to aid in the fine grading process of the subgrade to provide uniform
support under the slab.
' As discussed previously there is a chance that portions of the underlying soil could liquefy
during a seismic event. The foundation and structure itself will be supported by means of the
deep foundation (pile and grade beam) system discussed above, and therefore should not be
' affected by liquefaction. A unsupported "floating" slab however could experience some damage
should liquefaction occur. If such a risk to the floor slab is unacceptable, the floor should be
structurally connected to the foundation by way of grade beams, but should otherwise be placed.
as discussed above.
11.0 DRAINAGE CONSIDERATIONS
' The perimeter of the building should be provided with a drain at the pile cap elevation. Drains
should consist of rigid, perforated, PVC pipe surrounded by washed pea gravel. The level of
the perforations in the pipe should be set 2 inches below the bottom of the grade beam at all
' locations and the drains should be constructed with sufficient gradient to allow gravity discharge
away from the building. Roof and surface runoff should not discharge into the footing drain
8 `
' system but should be handled by a separate, rigid tightline drain. In planning, exterior grades
adjacent to walls should be sloped downward away from the structure to achieve surface
drainage.
' 12.0 PAVEMENT RECOMMENDATIONS
It is our understanding that the site surrounding the new building will be surfaced with a
' flexible, asphaltic concrete pavement (ACP). Our pavement design recommendations require
a firm, non-yielding subgrade. Site preparation should consist of removing all fill from the areas
to receive pavement. The subgrade surfaces should then be slightly crowned to drain to the
' edges of the paved areas. Next, the surface of the exposed soils should be recompacted with
a vibratory roller to a minimum of 95 percent of their maximum density as defined by ASTM:D
' 1557. After recompaction, the subgrade should be proofrolled with a fully loaded, tandem axle
dump truck to identify any soft or "pumping" areas. If such areas are observed, they should be
overexcavated and backfilled with structural fill. Once the natural soil subgrade has been
' observed and prepared as described herein, the fill soil could be placed and compacted to bring
the area back up to the proposed pavement subgrade. The suitability of the existing fill for use
as fill beneath pavement should be evaluated during construction by a representative of
' Associated Earth Sciences, Inc.
Since the majority of the pavement area will be used mainly for parking, we recommend that
' a separate pavement section be used for the low traffic parking areas. Our recommended
pavement section for the low traffic areas is as follows;
' 2 inches - Washington State Class B Asphaltic Concrete Pavement
5 inches - Compacted 5/8 inch minus crushed surfacing leveling course
' 6 inches - Sand and gravel pit run with less than 5 percent fines (as measured on the
minus #4 fraction) compacted to at least 95 percent of ASTM:D 1557
' For areas that will be used for more than parking areas, we recommend that the pit run base
material be increased to 12 inches. These pavement sections are based on a 20 year design life.
' 13.0 PROJECT DESIGN AND CONSTRUCTION MONITORING
We recommend that Associated Earth Sciences, Inc. perform a geotechnical review of the plans
' prior to final design completion. In this way, our earthwork and foundation recommendations
may be properly interpreted and implemented in the design.
' We are also available to provide geotechnical engineering and monitoring services during
construction. The integrity of the foundation depends on proper site preparation and construction
procedures. In addition, engineering decisions may have to be made in the field in the event that
' variations in subsurface conditions become apparent.
9
We have enjoyed working with you on this study and are confident that these recommendations
will aid in the successful completion of your project. If you should have any questions, or
' require further assistance, please do not hesitate to call.
Sincerely,
' ASSOCIATED EARTH SCIENCES, INC.
Kirkland, Washington
L G.
George H. Bennett, C.P.G.
Staff Geologist I /
0 � 30698
GISTS
SSI�NAL S'
EXPIRES 12/11 / (p
' Gary A. to ers, P.G. Michael G. Byers, P.E.
Principal Project Engineer
1
GHB/Id
10/1/95 Id-WP
' 10
1
sw GO y d way r
PROPOSED
PARKING
I `f EB-7
I EB_6 �
•
IAPARTMENTS
l �
I PROPOSED
PARKING SV 2th Street
3 f sw
1 y
NORTH
N
C
PROPOSED
PARKING z
PROPOSED EB-Z Q
J PARKING •
I � EB-3 EB-4 r——' 4
IFj PROPOSED Street
STRUCTURE SW 13th
LEGEND
IEB-5 EB-1 • Approximate location of
I — I • exploration boring
EB-1 r J
I • ( U 100 200
I L SCALE IN FEET '-
L�
1
1
SITE AND EXPLORATION PLAN
MM I
ASSOCIATEO
GOOD CHEVROLET PROPERTYIm EARTH
RENTON, WASHINGTON SCIENCES, INC
G95190A 9/95 1 FIGURE 1
EXPLORATION BORING LOG
' Number EB-1
STANDARD PENETRATION
F=— a Z w RESISTANCE
' SEDIMENT DESCRIPTION Q O= Q Blows/Foot
< 0
0
' 10 20 30 40
Surface: 1' topsoil/fill, broken glass shards. (Fill)
Dry to damp, dark brown, organic-rich SILT. At T dry, -r
yellow-brown, silty, fine SAND. A5
5
Moist, brown, sandy SILT. 3
Wet, dark gray with yellow mottling @ 8' to 9', fine to
medium SAND with wood, charcoal, and thin silt lenses. 10
---------------------------------------------------------------------
-� 11
Saturated, dark gray, fine to medium SAND with trace T WD A
' gravel. 1
15
As above, with wood. A21
20
As above with trace to some gravel, wood. 2
1
25
1 36
Saturated, dark gray, sandy GRAVEL. A
' 30
38
BOH @ 34' WD =while drilling
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by geologic
interpretations,engineering analysis,and judgment. They are not necessarily representative of other times and locations. We will not
accept responsibility for the use or interpretation by others of information presented on this log. Reviewed By G iq C
Associated Earth Sciences, Inc. Good Chevrolet Property
911 Fifth Avenue, Suite 100 Renton, Washington
' Kirkland, Washington 98033 Project NO. G95190A
Phone: 206-827-7701 September 1995
Fax: 206-827-5424
EXPLORATION BORING LOG
' Number E13-2
STANDARD PENETRATION
F=- a Z W RESISTANCE
SEDIMENT DESCRIPTION Q Q O0 Q Blows/Foot
10 20 30 40
Surface: Field sod 0 to 3".
' _
Damp, dark brown-gray SILT. 9
Damp, yellow-brown, mottled, fine SAND.
' 5
' T 28A
Moist to wet, dark gray, sandy GRAVEL.
10
' WD
Saturated, dark brown-gray, gravelly SAND with thin 10
' lenses of brown silt. _
15
Saturated, dark gray, sandy GRAVEL and gravelly T
23
SAND. 1
' 20
' Saturated, dark gray, gravelly SAND, some silt, trace
wood. 8
25
' Saturated, dark gray, sandy GRAVEL. 47A
i
' 30
' As above. - j 50/4"
BOH @ 34' WD -while drilling
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by geologic
' interpretations,engineering analysis,and judgment. They are not necessarily representative of other times and locations. We will not
accept responsibility for the use or interpretation by others of information presented on this log. Reviewed B
y
Associated Earth Sciences, Inc. Good Chevrolet Properly
911 Fifth Avenue, Suite 100 Renton, Washington
' Kirkland, Washington 98033 Project No. G95190A
Phone: 206-827-7701 September 1995
Fax: 206-827-5424
EXPLORATION BORING LOG
' Number E13-3
STANDARD PENETRATION
F=- a z W RESISTANCE
' SEDIMENT DESCRIPTION o Q 0 Blows/Foot
U)
' 10 20 30 40
04"Topsoil/sod; damp, dark brown, gravelly, sandy 17A,*
SILT with broken rock to 1'. (Fill) 1
Damp, dark brown SILT. 7
Damp, yellow-brown, mottled, silty, fine SAND to I
sandy GRAVEL.
5 '&43
BOH @ 6-1/2'
' * Blow count not representative due to rock in drive shoe.
10
' 15
' 20
' 25
i
30
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by geologic
' interpretations,engineering analysis,and judgment. They are not necessarily representative of other times and locations. We will not
accept responsibility for the use or interpretation by others of information presented on this log. Reviewed By
' Associated Earth Sciences, Inc. Good Chevrolet Property
911 Fifth Avenue, Suite 100 Renton, Washington
' Kirkland, Washington 98033 Project No. G95190A
Phone: 206-827-7701 September 1995
Fax: 206-827-5424
EXPLORATION BORING LOG
' Number EB-4
LLI OW STANDARD PENETRATION
� Z w RESISTANCE
' SEDIMENT DESCRIPTION Q Q 0 Blows/Foot
U
' 10 20 30 40
Sod 0 '3"; damp, dark brown, gravelly, sandy SILT, trace 10
organics to 1'; damp, dark brown, sandy SILT with
pebbles 1'to 3'. (Fill)
- --------------------------- - -- - - - - -- $
Damp, yellow-brown, mottled, fine SAND.
T
Damp, brown, mottled, gravelly, fine to medium SAND. 5 1
34
BOH @ 6-1/2'
10
' 15
20
' 25
30
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by geologic
' interpretations,engineering analysis,and judgment. They are not necessarily representative of other times and locations. We will not p
accept responsibility for the use or interpretation by others of information presented on this log. Reviewed By
' Associated Earth Sciences, Inc. Good Chevrolet Property
911 Fifth Avenue, Suite 100 Renton, Washington
Kirkland, Washington 98033 Project No. G95190A
Phone: 206-827-7701 September 1995
Fax: 206-827-5424
1 EXPLORATION O XPLO TION BORING LOG
1 Number EB-5
STANDARD PENETRATION
SEDIMENT DESCRIPTION aa.' a z w RESISTANCE
1
Q Q � Q Blows/Foot
W
0
1 10 20 30 40
Sod 0-5"; Damp, dark brown SILT, some organics. (Fill) A13
---------------------------------------------------------------------------------
1 Damp, yellow-brown, mottled, fine SAND. 8A
1 Wet, brown-gray, strongly mottled SILT, tiny roots, trace 5 _ 4
charcoal. A
BOH @ 6-1/2'
1
10
1
1 15
1
' 20
1
1 25
1
30
i
1
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by geologic
1 interpretations,engineering analysis,and judgment. They are not necessarily representative of other times and locations. We will not
accept responsibility for the use or interpretation by others of information presented on this log. Reviewed By F�
s'
1 Associated Earth Sciences, Inc. Good Chevrolet Property
911 Fifth Avenue, Suite 100 Renton, Washington
1 Kirkland, Washington 98033 Project NO. G95190A
Phone: 206-827-7701 September 1995
Fax: 206-827-5424
EXPLORATION BORING LOG
Number EB-6
' OW STANDARD PENETRATION
' H d Z w RESISTANCE SEDIMENT DESCRIPTION o QO Q Blows/Foot
U)
' 10 20 30 40
Damp, brown-gray, silty, fine SAND, trace to some A 22
gravel.
9-
Wet, brown-gray, strongly mottled, clayey SILT, trace 5
' tiny roots and black organics. �5
BOH @ 6-1/2'
10
' 15
' 20
25
30
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by geologic
interpretations,engineering analysis,and judgment. They are not necessarily representative of other times and locations. We will not
accept responsibility for the use or interpretation by others of information presented on this log. Reviewed By
' Associated Earth Sciences, Inc. Good Chevrolet Property
911 Fifth Avenue, Suite 100 Renton, Washington
' Kirkland, Washington 98033 Project No. G95190A
Phone: 206-827-7701 September 1995
Fax: 206-827-5424
EXPLORATION BORING LOG
Number EB-7
' W STANDARD PENETRATION
I=- _J Z w RESISTANCE
' SEDIMENT DESCRIPTION Q ¢ C Blows/Foot
U) cD
10 20 30 40
' Asphalt 0'-3"; moist, gray-brown, gravelly, silty, fine 18
SAND.
' Saturated zone 2-1/2'to 3-1/2' atop silt. T =
Damp, yellow-brown to brown-gray, sandy SILT. 5 9
BOH @ 6-1/2'
10
' 15
' 20
' 25
30
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modfed by geologic
interpretations,engineering analysis,and judgment. They are not necessarily representative of other times and locations. We will not
' accept responsibility for the use or interpretation by others of information presented on this log. Reviewed By Cl
Associated Earth Sciences, Inc. Good Chevrolet Property
911 Fifth Avenue, Suite 100 Renton, Washington
Kirkland, Washington 98033 Project NO. G95190A
' Phone: 206-827-7701 September 1995
Fax: 206-827-5424
GRAIN SIZE ANALYSIS - ME
CHANICAL
' Date Project Project No. Soil Description
9111/95 Good Chev.Prop G95190A
Tested By Location EB/EP No. JDepth
' ADF 1 .5 -9'
Before washing After washing Fines washed out
Wt.of Dry Sample+Tare ( 171.700 107.000
Wt. of Tare ( 0.000 0.000
Wt.of Dry Sample O 171.700 107.000 64.700
' R
Sieve No. Diam. mm Specification e uirements
Wt. Retained % Retained % Passin Minimum Maximum
3 76.1 0 0.0 100.0
2.5 64 0 0.0 100.0
2 50.8 0 0.0 100.0
1.5 38.1 0 0.0 100.0
' 1 25.4 0 0.0 100.0
3/4 19 0 0.0 100.0
5/8 16 0 0.0 100.0
7/16 11.11 0 0.0 100.0
3/8 9.51 0 0.0 100.0
5/16 8 0 0.0 100.0
1/4 6.35 0 0.0 100.0
#4 4.76 0.3 0.2 99.8
' #8 2.38 5.8 3.4 96.4
#16 1.19 10.6 6.2 90.3
#30 0.595 14.1 8.2 82.1
#40 0.42 11.1 6.5 75.6
' #50 0.297 1 12.6 1 7.3 1 68.3
#100 0.149 26.7 15.6 52.7
#200 0.074 27.3 15.9 36.8
' 65.000 37.9
US STANDARD SIEVE NOS.
' 3" 3/4" NOA NO.16 NO.40 NO.200
100
90
80
70 1
' c 60
lL
50
c
d 40
o
20
0
100 10 1 0.1 0.01
' Grain Size,mm
GRAVEL SAND SILT OR
Coarse Fine Coarse Medium Fine CLAY
ASSOCIATED EARTH SCIENCES, INC.
GRAIN SIZE ANALYSIS - MECHANICAL
' Date Project Project No. Soil Description
9/11/95 Good Chev.Prop G95190A .
Tested By Location EB/EP No. Depth
' ADF 2 122.5 -24'
Before washing After washing Fines washed out
' Wt. of Dry Sample+Tare ( 546.400 V 472.000
Wt. of Tare ( 0.000 0.000
Wt. of Dry Sample ) 546.400 472.000 74.400
' Specification Requirements
Sieve No. Diam. (mm) Wt. Retained % Retained % Passing Minimum Maximum
3 76.1 0 0.0 100.0
' 2.5 64 0 0.0 100.0
2 50.8 0 0.0 100.0
1.5 38.1 0 0.0 100.0
' 1 25.4 0 0.0 100.0
3/4 19 25.7 4.7 95.3
5/8 16 11.2 2.0 93.2
7/16 11.11 18.2 3.3 89.9
3/8 9.51 4.4 0.8 89.1
5/16 8 11 2.0 87.1
1/4 6.35 10.4 1.9 85.2
#4 4.76 11.4 2.1 83.1 -
' #8 2.38 26.8 4.9 78.2
#16 1.19 31.1 5.7 72.5
#30 0.595 70.5 12.9 59.6
' #40 0.42 66.7 12.2 47.4
#50 0.297 73.7 13.5 33.9
#100 0.149 86.7 15.9 1 18.0
#200 0.074 25.6 4.7 13.4
74.400 13.6
US STANDARD SIEVE NOS.
3- 3/4" NO.4 NO.16 NO.40 NO.200
100
90
80
70
Li 60
i
" 50
u
m` 40
a
20 '
0
100 10 1 0.1 0.01
' Grain Size,mm
GRAVEL SAND SILT OR
Coarse Fine Coarse Medium Fine CLAY
' ASSOCIATED EARTH SCIENCES, INC.
GRAIN SIZE ANALYSIS - MECHANICAL
' Date Project Project No. Soil Description
9/11/95 Good Chev.Prop G95190A
Tested By Location EB/EP No. Depth
ADF 1 22.5-24
Before washing After washing Fines washed out
' Wt. of Dry Sample+Tare ( 441.500 391.600
Wt. of Tare 0.000 0.000
Wt. of Dry Sample ( 441.500 391.600 49.900
Specification Requirements
Sieve No. Diam. (mm) Wt. Retained % Retained % PassingMinimum Maximum
3 76.1 0 0.0 100.0
' 2.5 64 0 0.0 100.0
2 50.8 0 0.0 100.0
1.5 38.1 0 0.0 100.0
1 25.4 0 0.0 100.0
' 3/4 19 0 0.0 100.0
5/8 16 9.4 2.1 97.9
7/16 11.11 12.2 2.8 95.1
t 3/8 9.51 6 1.4 93.7
5/16 8 4.8 1.1 92.7
1/4 6.35 3.3 0.7 91.9
#4 4.76 4.3 1.0 90.9
' #8 2.38 14.5 3.3 87.7
#16 1.19 39.2 8.9 78.8
#30 0.595 119.5 27.1 51.7
#40 0.42 64.5 14.6 37.1
' #50 0.297 1 49 1 11.1 26.0
#100 0.149 54.4 12.3 13.7
#200 0.074 11.7 2.7 11.0
' 49.900 11.3
US STANDARD SIEVE NOS.
' 3" 3/4" NO.4 NO.16 NO.40 NO.200
100
90
80
70
c 6044'u.
50
u '
`m 40
a
20
10
100 10 1 0.1 0.01
' Grain gize,mm
GRAVEL SAND SILT OR
Coarse Fine Coarse IMedium Fine CLAY
ASSOCIATED EARTH SCIENCES, INC.