HomeMy WebLinkAbout31E_Retaining Wall Geotech Letter& A S S O C I A T E S, I N C.
G E O T E C H N I C A L E N G I N E E R I N G E N V I R O N M E N T A L E N G I N E E R I N G
C O N S T R U C T I O N T E S T I N G & I N S P E C T I O N
Offices Serving the Western United States
1230 Finn Hill Road NW, Ste. A, Poulsbo, Washington 98370 (360) 598-2126 • Fax (360) 598-2127
August 21, 2024 Project No. 102-23007
Page 1 of 8
The Hamlet at Pleasant Harbor, LLC.
308913 U.S. Highway 101
Brinnon, Washington 98320
Attn: Mr. John Holbert
Email: johnholbert@startmail.com
Phone: (541) 740-0053
Reference: Limited Geotechnical Engineering Letter
Pleasant Harbor Development
Agra Center / Staff Housing Retaining Wall
30819 U. S. Highway 101
Brinnon, Washington
Dear Mr. Holbert,
Per your request we have prepared this limited geotechnical engineering letter for the site retaining walls
proposed for the Agra Center / Staff Housing grading, which is a part of Pleasant Harbor Development
project located at 30819 U.S. Highway 101 in Brinnon, Washington.
BACKGROUND AND INTRODUCTION
For our use in preparing this letter, we have reviewed the following documents:
Final Draft Geotechnical Investigation – Pleasant Harbor Marina and Golf Resort – Jefferson
County, Washington – Project No. SG0801”, prepared by Subsurface Group, LLC, dated January
23, 2013.
Civil Plan Sheets C1 to C3, prepared by Hatton Godat Pantier, dated June 2024.
A Draft Infiltration Feasibility Evaluation letter, prepared by Krazan and Associates, Inc., dated
June 10, 2024.
We understand that the northeast corner of the site will be developed with three buildings and associated
paved roads and parking areas. We understand that the proposed site grading will include construction of
seven (7) cast-in-place (CIPC) retaining walls. We understand that the walls height may range from about
8 to 20 feet, and the length may range from about 100 to 300 feet.
Exhibit 31E
KA Project No. 102-23007
Pleasant Harbor Development
Agra Center / Staff Housing Retaining Wall
August 21, 2024
Page No. 2
Krazan & Associates, Inc.
Offices Serving the Western United States
We have been requested to prepare this letter to provide geotechnical engineering recommendations for
use in design and construction of the proposed CIPC retaining walls.
FIELD INVESTIGATION
The field investigation consisted of a surface reconnaissance and a subsurface exploration program. Four
(4) exploratory test pits (TP-A through TP-D) were completed to evaluate the subsurface soil and
groundwater conditions at the site. This letter also references information from one test pit (TP-4) that
was previously excavated on October 20, 2023 as part of Krazan’s infiltration feasibility evaluation for
the proposed Pleasant Harbor Development.
We visited the site on June 25, 2024 to visually observe and log a previously excavated test pit, TP-A.
The depth of the TP-A at the time of our site visit was about 8.0 feet below existing ground surface (bgs).
The remainder of the test pits were excavated on July 19, 2024 by a client provided excavator (Caterpillar
326) and operator. TP-B, TP-C, and TP-D were excavated to depth of about 6.0 to 10.5 feet bgs. TP-4
was excavated to 10 feet bgs. The test pit explorations were located in the field based on existing site
features, and their approximate locations are shown on the Site Plan (Figure 1).
A geologist from Krazan and Associates was present during the explorations, continuously examined and
visually classified the soils in general accordance with the Unified Soil Classification System (USCS),
and maintained logs of the explorations.
SOIL PROFILE AND SUBSURFACE CONDITIONS
This section of the letter is intended to provide a general description the subsurface soil and groundwater
conditions exposed in our explorations. Detailed descriptions of the soils encountered in our explorations
are presented in the test pit logs attached to this letter. The depths shown on the attached logs are from
the existing ground surface at the time of our exploration.
Organic Topsoil and Forest Duff:Roughly 2 to 6-inches of organic topsoil was exposed in some of our
test pits. Roughly 6-inches of forest duff was exposed in TP-4.
Native Glacial Soils:Underlying the organic topsoil or forest duff, our test pits generally exposed moist,
medium dense to very dense, light brown to gray silty sand with varying amounts of gravel and cobbles
and gray sand with varying amounts of gravel and cobbles extending to the maximum explored depths of
about 6.0 to 10.5 feet bgs.We interpreted these soils to be native glacial deposits.
Groundwater Observations:Groundwater seepage was noted at approximately 4.5 feet bgs in test pit
TP-4. Groundwater seepage was not noted in the remaining test pits. However, it should be recognized
that groundwater elevations may fluctuate with time. The groundwater level will be dependent upon
seasonal precipitation, irrigation, land use, and climatic conditions, as well as other factors. Therefore,
Exhibit 31E
KA Project No. 102-23007
Pleasant Harbor Development
Agra Center / Staff Housing Retaining Wall
August 21, 2024
Page No. 3
Krazan & Associates, Inc.
Offices Serving the Western United States
groundwater levels at the time of the field investigation may be different from those encountered during
the construction phase of the project. The evaluation of such factors is beyond the scope of this report.
CONCLUSION AND RECOMMENDATIONS
It is our opinion from a geotechnical standpoint that the site is compatible with the proposed retaining
walls, provided that our geotechnical engineering recommendations are incorporated into project plans
and are implemented during construction.
Seismic Hazard
The 2021 International Building Code (IBC), Section 1613.3.2, refers to Chapter 20 of ASCE 7-16 for
Site Class Definitions. It is our opinion that the site soil conditions correspond to “Site Class C”. Site
Class C applies to a “stiff soil” profile. The seismic site class is based on a soil profile extending to a
depth of 100 feet. The recent test pits were only excavated to maximum depth of about 10.5 feet bgs.
However, the explorations performed by Subsurface Group, LLC extended to maximum depths of about
230 feet bgs.
We referred to the Applied Technology Council (ATC) website and 2021 IBC to obtain values for SS,SMS,
SDS,S1,SM1,SD1,Fa, and Fv. The ATC website utilizes the most updated published data on seismic
conditions from the United States Geological Survey. The seismic design parameters for this site are
presented in the following table:
Seismic Design Parameters
(Reference: 2021 IBC Section 1613.2.2, ASCE 7-16, and ATC)
Seismic Item Value
Site Coefficient Fa 1.200
Ss 1.476
SMS 1.771
SDS 1.181
Site Coefficient Fv 1.463
S1 0.537
SM1 0.786
SD1 0.524
Additional seismic considerations include liquefaction potential and amplification of ground motions by
soft soil deposits. The liquefaction potential is highest for loose sand with a high groundwater table. The
native glacial soils interpreted to underlie the site are considered to have a low potential for liquefaction
and amplification of ground motion.
Exhibit 31E
KA Project No. 102-23007
Pleasant Harbor Development
Agra Center / Staff Housing Retaining Wall
August 21, 2024
Page No. 4
Krazan & Associates, Inc.
Offices Serving the Western United States
Temporary Excavations
The on-site soils have variable cohesion strengths, therefore the safe angles to which these materials may
be cut for temporary excavations is limited, as the soils may be prone to caving and slope failures in
temporary excavations deeper than 4 feet. Temporary excavations in the existing materials should be
sloped no steeper than 1.5H:1V (horizontal to vertical) where room permits. Flatter inclinations or
temporary shoring may be necessary where caving conditions, and groundwater seepage are encountered.
All temporary cuts should be in accordance with Washington Administrative Code (WAC) Part N,
Excavation, Trenching, and Shoring. The temporary slope cuts should be visually inspected daily by a
qualified person during construction work activities and the results of the inspections should be included
in daily reports. The contractor is responsible for maintaining the stability of the temporary cut slopes and
minimizing slope erosion during construction. The temporary cut slopes should be covered with plastic
sheeting to help minimize erosion during wet weather and the slopes should be closely monitored until the
permanent retaining systems are complete. Materials should not be stored and equipment operated within
10 feet of the top of any temporary cut slope.
A Krazan & Associates geotechnical engineer or geologist should observe, at least periodically, the
temporary cut slopes during the excavation work. The reason for this is that all soil conditions may not
be fully delineated by the limited sampling of the site from the geotechnical explorations. In the case of
temporary slope cuts, the existing soil conditions may not be fully revealed until the excavation work
exposes the soil. Typically, as excavation work progresses the maximum inclination of the temporary
slope will need to be evaluated by the geotechnical engineer so that supplemental recommendations can
be made. Soil and groundwater conditions can be highly variable. Scheduling for soil work will need to
be adjustable, to deal with unanticipated conditions, so that the project can proceed smoothly and required
deadlines can be met. If any variations or undesirable conditions are encountered during construction,
Krazan & Associates should be notified so that supplemental recommendations can be made.
Retaining Walls
We have developedcriteriafor the designof retainingwalls. Our design parametersare basedon retention
of the native soils or structural fill. The wall design criteria are based on the total unit weight of backfill
of 134 pounds per cubic foot (pcf) and friction angle of 36 degrees. The parameters are also based on
level, well-drained wall backfill conditions.
Walls may be designed as “restrained” retaining walls based on “at-rest” earth pressures, plus any
surcharge on top of the walls as described below, if the walls are braced to restrain movement and/or
movement is not acceptable. Unrestrained walls may be designed based on “active” earth pressure, if the
walls are not part of the buildings and some movement of the retaining walls is acceptable. Acceptable
lateral movement equal to at least 0.2 percent of the wall height would warrant the use of “active” earth
Exhibit 31E
KA Project No. 102-23007
Pleasant Harbor Development
Agra Center / Staff Housing Retaining Wall
August 21, 2024
Page No. 5
Krazan & Associates, Inc.
Offices Serving the Western United States
pressure values for design. The following table, titled Wall Design Criteria, presents the recommended
soil related design parameters for retaining walls.
Wall Design Criteria
“At-rest” Conditions (Lateral Earth Pressure)
(Level Backfill)
60 pcf (Equivalent Fluid Density) (Triangular
Distribution)
“At-rest” Conditions
(5 Degrees Backslope)
66 pcf
“At-rest” Conditions
(10 Degrees Backslope)
70 pcf
“Active” Conditions (Lateral Earth Pressure)
(Level Backfill)
40 pcf (Equivalent Fluid Density) (Triangular
Distribution)
“Active” Conditions
(5 Degrees Backslope)
43 pcf
“Active” Conditions (Lateral Earth Pressure)
(10 Degrees Backslope)
46 pcf
Seismic Increase for “Active” Conditions
(Lateral Earth Pressure) (Level Backfill)
8 psf x H (Uniform Distribution)
Where H is the height of the wall in feet
Seismic Increase for “Active” Conditions
(5 Degrees Backslope)
10 psf x H
Seismic Increase for “Active” Conditions
(10 Degrees Backslope)
12 psf x H
If vehicular loads are expected to act behind the wall within a horizontal distance of less than or equal to
one-half of the wall height, then a live load surcharge should be applied for the design. In this case, we
recommend the addition of vehicle surcharges of 70 psf and 100 psf to the active and at-rest earth
pressures, respectively.
The stated lateral earth pressures do not include the effects of hydrostatic pressure generated by water
accumulation behind the retaining walls or loads imposed by construction equipment, foundations or
roadways adjacent to the wall (surcharge loads). To minimize the lateral earth pressure and reduce the
buildup of water pressure against the walls, continuous footing drains (with cleanouts) should be provided
at the bases of the walls. The footing drains should consist of a minimum 4-inch diameter rigid PVC
perforated pipe, sloped to drain, with perforations placed near the bottom. The drainpipe should be
Exhibit 31E
KA Project No. 102-23007
Pleasant Harbor Development
Agra Center / Staff Housing Retaining Wall
August 21, 2024
Page No. 6
Krazan & Associates, Inc.
Offices Serving the Western United States
enveloped by 6 inches of washed gravel in all directions wrapped in filter fabric to prevent the migration
of silt and clay into the drain.
The wall fills adjacent to and extending a lateral distance of at least 2 feet behind the walls should consist
of free-draining granular material. All free-draining backfill should contain less than 3 percent fines
(passing the U.S. Standard No. 200 Sieve) based upon the fraction passing the U.S. Standard No. 4 Sieve
with at least 30 percent of the material being retained on the U.S. Standard No. 4 Sieve.Alternatively,a
drainage composite may be used. It should be realized that the primary purpose of the free-draining
material is the reduction of hydrostatic pressure. Some potential for the moisture to contact the back face
of the wall may exist, even with treatment, which may require that more extensive waterproofing be
specified for walls, which require interior moisture sensitive finishes.
We recommend that the wall fill be compacted to at least 95 percent of the maximum dry density based
on ASTM D1557 Test Method. In-place density tests should be performed to verify adequate compaction.
Soil compactors place transient surcharges on the backfill. Consequently, only light hand operated
equipmentisrecommendedforfillcompactionwithin3feetofwallssothatexcessive stressisnotimposed
on the walls.
Subgrade Preparation:In the planned footing area, any loose/soft soils or organics should be excavated
toexposetheunderlyingfirmnativesoils. Theresultingexcavationsshouldbefilledtotheplannedbottom
of the structure’s subgrade elevations with suitable soils as per the Structural Fill section of this letter.
Based on thesoil explorations at thesite, we interpretthe medium dense or firmer nativeload bearing soils
at this site to be about 2 to 3 feet bgs.
Soil Bearing:Conventional shallow spread footings supported on medium dense or firmer native soils,
or on structural fill extending to the medium dense or firmer native soils, may be designed using an
allowable soil bearing pressure of 2,500 pounds per square foot (psf)for dead plus live loads. This value
may be increased by 1/3 for short duration loads such as wind or seismic loading. A representative of
Krazan and Associates should evaluate the foundation bearing soil and observe structural fill placement,
where utilized.
For frost protection and bearing capacity considerations, footings should have a minimum embedment
depth of 18 inches below adjacent exterior grade. Footing widths should be based on the anticipated loads
and allowable soil bearing pressure. Footings should have a minimum width of at least 12 inches
regardless of load. Water should not be allowed to accumulate in footing trenches. All loose or disturbed
soils should be removed from the foundation excavations prior to placing concrete.
Design Parameters – Lateral Resistance:Resistance to lateral displacement can be computed using an
allowable friction factor of 0.4 acting between the bases of foundations and the supporting subgrade soil.
Lateral resistance for footings can alternatively be developed using an allowable equivalent fluid passive
pressure of 250poundspercubic foot(pcf) actingagainstthe appropriate verticalfooting faces(neglecting
Exhibit 31E
KA Project No. 102-23007
Pleasant Harbor Development
Agra Center / Staff Housing Retaining Wall
August 21, 2024
Page No. 7
Krazan & Associates, Inc.
Offices Serving the Western United States
the upper 12 inches). The allowable friction factor and allowable equivalent fluid passive pressure values
include a factor of safety of 1.5. The frictional and passive resistance of the soil may be combined without
reduction in determining the total lateral resistance.
Structural Fill
Fill placed beneath foundations or other settlement-sensitive structures should be placed as structural fill.
Structural fill, by definition, is placed in accordance with prescribed methods and standards, and is
monitored by an experienced geotechnical professional. Field monitoring procedures would include the
performance of a representative number of in-place density tests to document the attainment of the desired
degree of relative compaction. The area to receive the fill should be suitably prepared as described in the
Retaining Wall section of this letter prior to beginning fill placement. A representative of the Krazan
should evaluate the subgrade prior to structural fill placement.
BMP’s should be followed when considering the suitability of the existing materials for use as structural
fill. Thenative granular soils may be reused as structural fill, providedthatthat they are within ± 2 percent
of the optimum moisture content during placement.
Imported, all weather granular structural fill material should consist of well-graded gravel or a sand and
gravel mixture with a maximum grain size of 3 inches and less than 5 percent fines (material passing the
U.S. Standard No. 200 Sieve). Structural fill can also consist crushed rock, rock spalls and controlled
density fill (CDF). All structural fill material should be submitted for approval to the geotechnical
engineer at least 48 hours prior to delivery to the site.
Granular structural fill soils should be placed in horizontal lifts not exceeding 8 inches in thickness prior
to compaction, moisture-conditioned as necessary, (moisture content of soil shall not vary by more than
±2 percent of optimum moisture) and the material should be compacted to at least 95 percent of the
maximum dry density based on ASTM D1557 Test Method. In-place density tests should be performed
onallstructuralfillto documentpropermoisturecontentandadequatecompaction. Additionalliftsshould
not be placed if the previous lift did not meet the compaction requirements or if soil conditions are not
considered stable.
TESTING AND INSPECTIONS
A representative of Krazan & Associates, Inc. should be present at the site during the earthwork activities
to confirm that actual subsurface conditions are consistent with the exploratory fieldwork. This activity
is an integral part of our services as acceptance of earthwork construction is dependent upon compaction
testing and stability of the material. This representative can also verify that the intent of these
recommendations is incorporated into the project design and construction. Krazan & Associates, Inc. will
not be responsible for grades or staking, since this is the responsibility of the Prime Contractor.
Furthermore, Krazan & Associates is not responsible for the contractor’s procedures, methods, scheduling
or management of the work site.
Exhibit 31E
KA Project No. 102-23007
Pleasant Harbor Development
Agra Center / Staff Housing Retaining Wall
August 21, 2024
Page No. 8
Krazan & Associates, Inc.
Offices Serving the Western United States
Furthermore, Krazan & Associates is not responsible for the contractor’s procedures, methods, scheduling
or management of the work site.
LIMITATIONS
The recommendationsmade in this letterare based onthe assumption that soilandgroundwater conditions
do not vary significantly from those disclosed during our field investigation. If any variations or
undesirable conditions are encountered during construction, the geotechnical engineer should be notified
so that supplemental recommendations can be made.
This letter has been prepared for the exclusive use of The Hamlet at Pleasant Harbor, LLC, and its agents,
for the specific application to the subject site. The conclusions of this letter are based on the information
provided regarding any proposed construction. If construction is relocated or redesigned, the conclusions
in this letter may not be valid. The geotechnical engineer should be notified of any changes so that the
recommendations can be reviewed and re-evaluated.
The information presented herein is based upon professional interpretation utilizing standard engineering
practices and a degree of conservatism deemed proper for this project. It is not warranted that such
informationandinterpretationcannotbesupersededbyfuture developments.Weemphasizethatthisletter
is valid for this project as outlined above, and should not be used for any other site or any other
development at the project site.
CLOSURE
We appreciate the opportunity to provide this service for you. If you have any questions, or if we may be
of further assistance, please do not hesitate to contact our office at (360) 598-2126.
Respectfully submitted,
KRAZAN & ASSOCIATES, INC.
Vijay Chaudhary, P.E.
Project Engineer
Attachments:Figure 1 – Site Plan
Test Pit Logs
8/21/24
Exhibit 31E
Site PlanDate: July-2024Project Number: 102-23007Reference: Job Sheet C1, Job 19-060, Agra Center/ Staff Housing Site Plan, prepared by Hatton Godat PantierEngineers and Surveyors,dated June 2024.Drawn by: EA Figure: 1Not to scaleTP-ANumber and Approximate Location of 2024 Test PitTP-ATP-BTP-CTP-DTP-4TP-4Number and Approximate Location of Krazan 2023 Test PitPleasant Harbor Development - Agra Center / Staff Housing Retaining WallExhibit 31E
Project Number: 102-23007
& A S S O C I A T E S, I N C.
Date: August 2024
Drawn By: VC
References: USCS
Soil Classification
Pleasant Harbor Development - Agra Center / Staff Housing Retaining Wall
Relative Density with Respect to SPT N-Value
Coarse-Grained Soils
Density
Very Loose Very Soft
Soft
Medium Stiff
Stiff
Very Stiff
Hard
0 - 4 0 - 1
2 - 4
5 - 8
9 - 15
16 - 30
> 30
5 -10
11 - 30
31 - 50
> 50
Loose
Medium Dense
Dense
Very Dense
DensityN-Value (Blows/Ft)N-Value (Blows/Ft)
Fine-Grained Soils
USCS Soil Classification
Major Division
Coarse-
Grained
Soils
< 50%
passes
#200
sieve
Gravel and
Gravelly Soils
< 50% coarse
fraction passes
#4 sieve
Gravel
(with little or no fines)
GW Well-Graded Gravel
Poorly Graded Gravel
Silty Gravel
Clayey Gravel
Well-Graded Sand
Poorly Graded Sand
Silty Sand
Clayey Sand
Silt
Lean Clay
Organic Silt and Clay (Low Plasticity)
Inorganic Silt
Inorganic Clay
Organic Clay and Silt (Med. to High Plasticity)
Peat
GP
GM
GC
SW
SP
SM
SC
ML
CL
OL
MH
CH
OH
PT
Sand
(with little or no fines)
Gravel
(with > 12% fines)
Sand
(with > 12% fines)
Sand and
Sandy Soils
> 50% coarse
fraction passes
#4 sieve
Silt and Clay
Liquid Limit < 50
Silt and Clay
Liquid Limit > 50
Highly Organic Soils
Fine-
Grained
Soils
> 50%
passes
#200
sieve
Group Description
Exhibit 31E
LOG OF EXPLORATORY TEST PIT
PROJECT:
PROJECT NO.:PAGE: 1 of 1
DATE:
SURFACE ELEV.:CONTRACTOR:
SAMPLE METHOD:LOCATION:
Water Observations:
Notes:Logged By:DEPTH (ft)
1
2
3
4
5
6
7
8 USC SYMBOLWATER LEVEL
MATERIAL DESCRIPTION
SAMPLE No.SAMPLE TYPE
Moisture Content and
Atterberg Limits
1020304050607080
KRAZAN AND ASSOCIATES, INC.
Water Level Initial:#Final:$
TP-A
Pleasant Harbor
102-23007
June 25, 2024
~160 ft.Pleasant Harbor
Grab Brinnon, WA
Light brown, silty sand with gravel (SM) (moist, medium dense)
-Roots were noted from surface to 2.0 ft.
-Cobbles and boulders were encountered.
Gray, sand with gravel (SP-SM) (moist, medium dense)
-Cobbles were noted.
Gray, sand (SP) (moist, medium dense)
Gray, sand with gravel (SP-SM) (moist, very dense)
-0.5 ft. gravel lens was encountered from 7.0 to 7.5 ft.
End of Exploratory Test Pit
Groundwater was not encountered.
Excavation was open for 10 days and slight caving was observed.SEW
Exhibit 31E
LOG OF EXPLORATORY TEST PIT
PROJECT:
PROJECT NO.:PAGE: 1 of 1
DATE:
SURFACE ELEV.:CONTRACTOR:
SAMPLE METHOD:LOCATION:
Water Observations:
Notes:Logged By:DEPTH (ft)
1
2
3
4
5
6
7
8
9
10
11 USC SYMBOLWATER LEVEL
MATERIAL DESCRIPTION
SAMPLE No.SAMPLE TYPE
Moisture Content and
Atterberg Limits
1020304050607080
KRAZAN AND ASSOCIATES, INC.
Water Level Initial:#Final:$
TP-B
Pleasant Harbor
102-23007
July 19, 2024
~155 ft.The Statesman Group
Grab Brinnon, WA
Organic topsoil
Light brown to gray, sand with gravel (SP-SM) (moist, medium dense)
-Roots were encountered from 0.5 ft. to 7.0 ft.
-Cobbles were encountered.
Gray, silty sand with gravel (SM) (moist, medium dense)
Gray, sand with gravel (SP-S M) (moist, medium dense to dense)
-Cobbles were encountered.
-Becomes dense.
End of Exploratory Test Pit
S1
S2
Groundwater was not observed.
Caving was not observed.SEW
Exhibit 31E
LOG OF EXPLORATORY TEST PIT
PROJECT:
PROJECT NO.:PAGE: 1 of 1
DATE:
SURFACE ELEV.:CONTRACTOR:
SAMPLE METHOD:LOCATION:
Water Observations:
Notes:Logged By:DEPTH (ft)
1
2
3
4
5
6
7
8
9
10
11 USC SYMBOLWATER LEVEL
MATERIAL DESCRIPTION
SAMPLE No.SAMPLE TYPE
Moisture Content and
Atterberg Limits
1020304050607080
KRAZAN AND ASSOCIATES, INC.
Water Level Initial:#Final:$
TP-C
Pleasant Harbor
102-23007
July 19, 2024
~200 ft.The Statesmen Group
Grab Brinnon, WA
Organic topsoil
Light brown, silty sand with gravel (SM) (moist, medium dense)
-Roots were encountered from 0.3 ft. to 2.0 ft.
Gray, sand with gravel (SP-SM) (moist, medium dense to dense)
-Becomes dense and cobbles were encountered from 8.0 to 10.0
ft.
End of Exploratory Test Pit
Groundwater was not observed.
Caving was not observed.SEW
Exhibit 31E
LOG OF EXPLORATORY TEST PIT
PROJECT:
PROJECT NO.:PAGE: 1 of 1
DATE:
SURFACE ELEV.:CONTRACTOR:
SAMPLE METHOD:LOCATION:
Water Observations:
Notes:Logged By:DEPTH (ft)
1
2
3
4
5
6
7
8
9
10
11 USC SYMBOLWATER LEVEL
MATERIAL DESCRIPTION
SAMPLE No.SAMPLE TYPE
Moisture Content and
Atterberg Limits
1020304050607080
KRAZAN AND ASSOCIATES, INC.
Water Level Initial:#Final:$
TP-D
Pleasant Harbor
102-23007
July 19, 2024
~200 ft.The Statesmen Group
Grab Brinnon, WA
Organic topsoil
Light brown, silty sand with gravel (SM) (moist, medium dense)
Gray, sand with gravel (SP-SM) (moist, dense to very dense)
-Becomes very dense. Cobbles were encountered from 5.0 ft. to
6.0 ft.
End of Exploratory Test Pit
Groundwater was not observed.
Caving was not observed.SEW
Exhibit 31E
PAGE INTENTIONALLY LEFT BLANK
Exhibit 31E
LOG OF EXPLORATORY TEST PIT
PROJECT:
PROJECT NO.:PAGE: 1 of 1
DATE:
SURFACE ELEV.:CONTRACTOR:
SAMPLE METHOD:LOCATION:
Water Observations:
Notes:Logged By:DEPTH (ft)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15 USC SYMBOLWATER LEVEL
MATERIAL DESCRIPTION
SAMPLE No.SAMPLE TYPE
Moisture Content and
Atterberg Limits
1020304050607080
KRAZAN AND ASSOCIATES, INC.
Water Level Initial:#Final:$
TP-4
Pleasant Harbor
102-23007 1
October 20, 2023
129.96 ft.Mahan Log & Lumber
Grab Brinnon, WA
Forest duff
Reddish brown to gray, silty sand with gravel (SM) (moist, medium
dense to very dense)
-Roots were encountered.
-Cobbles were encountered throughout.
-Becomes gray and dense.
-Becomes very dense and cemented.
End of Exploratory Test Pit
Moderate water seepage at 4.5 ft.
Caving was not observed.SEW
Exhibit 31E