05 Longmire Development Draft Technical Memorandum 8.3.2021Draft Technical Memorandum
500 Columbia St NW, Ste 110 • Olympia, WA 98501 • 360.791.3178
TO: Ben Fransua, Director of Construction, South Puget Sound Habitat for Humanity
FROM: Lance Levine, PE , and Calvin McCaughan, PE
DATE: August 3, 2021
RE: Summary of Geotechnical Engineering Services
Longmire Development
Yelm, Washington
Project No. 1592003.010.011
Introduction
This memorandum summarizes the results of geotechnical engineering services provided by Landau
Associates, Inc. (LAI) in support of the Longmire Development project, located at 407 Longmire Street
Northwest in Yelm, Washington (site; Figure 1).
This memorandum was prepared with information provided by South Puget Sound Habitat for
Humanity (SPSH4H; project owner) and with data collected during LAI’s geotechnical field exploration
and laboratory testing pr ograms.
Project Understanding
SPSH4H proposes to develop the site with single-family residences, associated utilities, stormwater
infiltration facilities, and a paved access road and driveways. The residences will be supported on
shallow foundations. The access road and driveways likely will be constructed with pervious surfaces.
Site Conditions
The site consists of an 8.46-acre parcel (Thurston County parcel number 22719230700), currently
developed with a single -family residence, garage, storage shed, an d septic drainfield. Undeveloped
portions of the site are vegetated with grass and several fruit trees. The site is bordered by Longmire
Street Northwest to the southeast, by Coates Avenue Northwest to the northeast, by Cullens Street
Northwest to the northwest and by single-family residences to the southwest. The site slopes gently
to the north, with a total relief of 4 feet (ft).
Geologic Setting
Geologic information for the site and the surrounding area was obtained from the Geologic Map of
the Centralia Quadrangle, Washington (Schasse 1987). Subsurface deposits in the vicinity of the site
are mapped as Vashon age outwash gravel (Qdvg). This unit typically consists of medium dense to
dense, proglacial and recessional, stratified gravel, cobbles, and boulders deposited in meltwater
streams and deltas. The soils observed in LAI's July 2021 explorations were generally consistent with
the mapped geology.
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Summary of Geotechnical Engineering Services
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Subsurface Explorations
On July 6, 2021, LAI explored site subsurface conditions by excavating six test pits (TP-1 through TP-6)
10.0 to 12.0 ft below ground surface (bgs). The test pits were excavated at the approximate locations
shown on Figure 2.
LAI personnel monitored the field explorations, collected representative soil samples, and maintained
detailed logs of the subsurface soil and groundwater conditions observed. Subsurface conditions were
described using the soil classification system shown on Figure 3, in general accordance with ASTM
International (ASTM) standard test method D2488, Standard Practice for Description and
Identification of Soils (Visual -Manual Procedures). Summary logs of the explorations are presented on
Figures 4 through 6.
Samples were transported to LAI’s soils laboratory for further examination and classification. Natural
moisture content determinations were performed on select soil samples in accordance with ASTM
standard test method D2216, Standard Test Methods for Laboratory Determination of Water
(Moisture) Content of Soil and Rock by Mass. The natural moisture content i s shown as W = xx (i.e.,
percentage of dry weight) in the “Test Data” column on Figures 4 through 6. Grain size analyses were
performed in accordance with ASTM standard test method D422, Standard Test Method for Particle -
Size Analysis of Soils. Samples selected for grain size analysis are designated with a “GS” in the “Test
Data” column on Figures 4 through 6. The results of the grain size analyses are presented on Figures 7
through 9.
Soil Conditions
The soils observed underlying existing surface condition s (i.e., topsoil) were categorized into one
general unit:
• Recessional outwash: Recessional outwash was observed beneath the topsoil in all six test
pits. The recessional outwash typically consisted of grayish -brown to brown, sandy gravel or
gravelly sand with variable silt, cobble, and boulder content in a medium dense to dense
condition. All six test pits were terminated following moderate to severe caving in the
recessional outwash unit.
Groundwater Conditions
No groundwater or groundwater seepage was obs erved in LAI’s July 2021 explorations. The
groundwater conditions reported herein are for the specific locations and date indicated and may not
be representative of other locations and/or times. Groundwater conditions will vary depending on
local subsurface conditions, weather conditions, and other factors. Site groundwater levels are
expected to fluctuate seasonally, with maximum groundwater levels occurring during late winter and
early spring.
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Conclusions and Recommendations
The near-surface soils observed in LAI’s explorations will provide adequate support of the proposed
shallow foundations and pavement sections. LAI recommends stripping a pproximately 9 inches of
topsoil to expose sand and gravel soils that are suitable for reuse as structural fill. Site soils are
suitable for stormwater infiltration. The following geotechnical recommendations should be
incorporated into the project design.
Seismic Design Considerations
LAI understands that seismic design will be completed using 2018 International Building Code
standards (ICC 2017). The parameters in Table 1 can be used to compute seismic base shear forces.
Table 1. 2018 International Building Code Seismic Design Parameters
Spectral response acceleration at short periods (S S) = 1.292g
Spectral response acceleration at 1 -second periods (S1) = 0.466g
Site class = D
Site coefficient (Fa) = 1.0
Site coefficient (Fv) = 1.834(a)
(a) When using the coefficient Fv = 1.834, adhere to Exception 2 requirements for a ground motion hazard analysis. See
Section 11.4.8 of the American Society of Civil Engineers’ Minimum Design Loads and Associated Criteria for Buildings and
Other Structures (ASCE/SEI 7-16).
Fa, Fv = acceleration (0.2-second period) and velocity (1.0-second period) site coefficients, respectively
g = force of gravity
Ss, S1 = 0.2-second and 1.0-second period spectral accelerations, respectively
Based on the subsurface conditions observed in LAI’s explorations, there is a low risk that seismically
induced soil liquefaction will occur at the si te following the design -level earthquake. Given the
distance between the site and the nearest known active crustal fault, the risk of ground rupture due
to surface faulting is low.
Foundation Support
Shallow foundations should be constructed on recessiona l outwash soil or on structural fill extending
to such soil. The design parameters in Table 2 should be used in conjunction with the complete
recommendations in this memorandum.
DRAFT Landau Associates
Summary of Geotechnical Engineering Services
Longmire Development 4 August 3, 2021
Table 2. Summary of Design Parameters for Shallow Foundations
Allowable soil bearing pressure = 3,500 psf
Friction coefficient (factored) = 0.35
Passive earth pressure = 330 pcf
Minimum foundation width = 18 inches (continuous), 24 inches (isolated)
pcf = pounds per cubic foot
psf = pounds per square foot
When developing design parameters, LAI assumed that shallow foundations would be established on
medium dense to dense subgrades prepared as recommended herein. The geotechnical engineer
should evaluate prepared subgrades prior to placement of structural fill.
The allowable soil bearing pressure in Table 2 applies to long -term dead and live loads, exclusive of
the weight of the footing and any overlying backfill. The bearing pressure can be increased by one -
third for transient loads, such as those induced by wind a nd seismic forces.
For frost protection, perimeter footings should be embedded at least 12 inches below the lowest
adjacent grade, where the ground is flat. Interior footings should be embedded at least 6 inches
below the nearest adjacent grade. LAI estimates that continuous and isolated foundations will settle 1
inch or less if constructed as recommended. Differential settlement between similarly loaded
foundation elements is estimated to be on the order of ½ inch or less. Settlement is expected to o ccur
as building loads are applied during construction.
An allowable coefficient of sliding resistance of 0.35, applied to vertical dead loads only, can be used
to compute frictional resistance acting on the base of footings. This coefficient includes a fa ctor of
safety of 1.5 on the calculated ultimate value.
The passive resistance of properly compacted structural fill placed against the sides of foundations
can be considered equivalent to a fluid with a density of 330 pounds per cubic foot. The foundatio n
passive earth pressure has been reduced by a factor of 1.5 to limit deflections to less than 2 percent
of the embedded depth. The passive earth pressure and friction components can be combined,
provided the passive component does not exceed two -thirds of the total. The top foot of soil should
be excluded from the calculation, unless the foundation perimeter will be covered by slab -on-grade or
pavement.
Slabs -On-Grade
Slabs-on-grade should be installed on a uniformly firm, unyielding subgrade that consists of sand
and/or gravel. A modulus of vertical subgrade reaction (subgrade modulus) can be used to design
slabs-on-grade. The subgrade modulus will vary based on the dimensions of the slab and the
DRAFT Landau Associates
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magnitude of applied loads on the slab surface; slab s with larger dimensions and loads are influenced
by soils to a greater depth. LAI recommends using a subgrade modulus of 220 pounds per cubic inch
to design on-grade floor slabs. This subgrade modulus is for a 1 -ft-by-1-ft square plate and is not the
overall modulus of a larger area.
Interior slabs-on-grade should include a vapor barrier and a capillary break layer, designed and
installed in accordance with industry standards.
Hot -Mix Asphalt Pavements
The asphalt pavement section should be constructed on compacted subgrade (i.e., on existing sand
and gravel) prepared as recommended herein. When developing the recommendations in Table 3, LAI
assumed a 20-year design life and a maximum equivalent single -axle load of 50,000 for the private
roadway local access residential pavement section and 500,000 for the neighborhood collector
section. The recommendations in T able 3 accord with the City of Yelm’s minimum street design
standards (2019).
Table 3. Recommended Asphalt Pavement Design Section (a)
Pavement Section Type Asphalt Concrete
Pavement Thickness
Crushed Surfacing Top
Course Thickness Ballast
Neighborhood Collector 3 inches 2 inches 8 inches
Private Roadway Local
Access Residential 2 inches 2 inches 8 inches
(a) Refer to Yelm Engineering Specifications and Standard Details (City of Yelm 2019).
Ballast and top course material should be compacted to at least 95 percent of the maximum dry
density, determined in accordance with ASTM standard test method D1557, Standard Test Method s
for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft -lbf/ft3 (2,700 kN-
m/m3)).
Compacted ballast should meet the requirements for Ballast in Section 9 -03.9(1) of the Washington
State Department of Transportation’s 2021 Standard Specifications for Road, Bridge, and Municipal
Construction (2021 WSDOT Standard Specifications ). Alternatively, ballast may meet the requirements
for Permeable Ballast in Section 9 -03.9(2). Compacted top course should meet the requirements for
Crushed Surfacing Top Course in Section 9 -03.9(3) of the 2021 WSDOT Standard Specifications.
Prevention of road -base saturation is essential for pavement durability; efforts should be made to
limit the amount of water entering the ballast and top course.
Asphalt concrete should be Class B aggregate material or hot -mix asphalt (HMA), class ½ inch and
PG58H-22 binder. Asphalt should conform to the requirements in Section 5 -04 of the 2021 WSDOT
Standard Specifications and be compacted to at least 91 percent of the R ice density.
DRAFT Landau Associates
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Permeable Pavement
Permeable pavements will consist of [permeable] HMA or a concrete wearing surface, an aggregate
storage layer, and subgrade soil . The subgrade soil should have the infiltration capacity to drain water
from the aggregate storage layer.
Permeable pavement is suited for very low -volume, slow-speed locations with infrequent truck traffic
(WSDOT 2018), including :
• Sidewalks, bicycle trails, community trail/pedestrian path systems, or other pedestrian-
accessible paved areas (e.g., traffic islands).
• Light vehicle-access areas, such as maintenance/enforcement areas on divided highways.
• Parking lots, including perimeter and overflow parking areas.
• Driveways.
To promote infiltration, compaction of permeable pavement subgrades should be avoided. Minimum
permeable pavement thicknesses are recommended in Table 4.
Table 4. Recommended Permeable Pavement Design Sections
Facility Hot-Mix Asphalt Portland Cement Concrete Pavement
Light vehicle-access areas 6 inches permeable HMA
12 inches (permeable base)
9 inches undoweled, permeable PCCP
12 inches (permeable base)
Parking 6 inches permeable HMA
12 inches (permeable base)
9 inches undoweled, permeable PCCP
12 inches (permeable base)
Pedestrian sidewalks and trails 3 inches permeable HMA
12 inches (permeable base)
4.5 inches undoweled , permeable PCCP
12 inches (permeable base)
HMA = hot-mix asphalt
PCCP = Portland cement concrete pavement
LAI recommends that permeable base meets the requirements for Permeable Ballast in Section 9 -
03.9(2) of the 2021 WSDOT Standard Specifications. Asphalt concrete should be Class B aggregate
material or HMA, class ½ inch and PG58H-22 binder. HMA should conform to the requirements in
Section 5-04 of the 2021 WSDOT Standard Specifications , and the binder should be 6.0 to 7.0 percent
by total weight. Separation fabric should be placed between native soils and the permeable base. The
fabric should satisfy the cri teria in Table 2, Section 9 -33.2(1) of the 2021 WSDOT Standard
Specifications.
A maintenance plan, approved by the City of Yelm, will be required for permeable pavements.
Maintenance standards are provided in the Washington State Department of Ecology’s 2019
Stormwater Management Manual for Western Washington (2019 SWMMWW).
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Stormwat er Infiltration
Groundwater and soil mottling were not observed in LAI’s July 2021 explorations, which extended to a
maximum depth of 12.0 ft bgs. LAI recommends that a seasonal high groundwater elevation of 20 ft
bgs is used to design stormwater facilitie s. Site groundwater levels are expected to fluctuate
seasonally, with maximum groundwater levels occurring during late winter and early spring.
The stormwater infiltration facilities will be constructed in accordance with the 2019 SWMMWW. The
site is underlain by soils belonging to hydrologic soil group A (USDA NRCS, accessed July 16, 2021). As
such, the infiltration rates in Table 5 were developed using the results of LAI’s geotechnical laboratory
tests (Figures 7 through 9) and the soil grain size analys is method. In LAI's opinion, stormwater
generated on site will disperse rapidly, and there is a low risk of groundwater mounding.
The following correction factors were applied to the infiltration rates to account for site variability
(CFv=0.8), testing method (CFt=0.4), and maintenance (CFm=0.9). When calculating infiltration rates,
LAI assumed a depth -to-groundwater of 16 ft bgs, measured from the base of the infiltration facility.
Table 5. Preliminary Infiltration Rates
Exploration Depth Interval
(ft)
Factored Infiltration
Rate
(in/hr)
TP-1 1–7 1.8
TP-1 7–10.5 7.5
TP-2 1–8 3.6
TP-2 8–10 9.4
TP-3 1–5 2.0
TP-3 5–10.5 3.9
TP-4 1–6 5.9
TP-4 6–12 1.4
TP-5 1–7 6.4
TP-5 7–10 5.4
TP-6 1–2.5 0.4
TP-6 2.5–10.5 2.2
ft = foot/feet
in/hr = inches per hour
DRAFT Landau Associates
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Site Drainage
LAI recommends that perimeter foundation footing drains are included in the design of structures.
Landscape and hardscape should slope away from structures at a grade of at least 2 percent.
Construction Considerations
The following key points should be considered when developing project plans and specifications:
• Stripping: Approximately 9 inches of topsoil (dark brown, gravelly sand with silt) should be
stripped from areas designated for development (i.e., the proposed locatio ns of footings,
slabs-on-grade, and pavement sections). Topsoil is not considered suitable for reuse as
structural fill.
• Subgrade preparation: Before structural fill, formwork, or pavement base course is placed,
the prepared subgrade should be proof -rolled in the presence of a qualified geotechnical
engineer, who is familiar with the site and can check for soft/disturbed areas. Areas of limited
access can be evaluated with a steel T -probe. If probing or proof-rolling reveals loose and/or
disturbed subgrades, the upper 1 ft of subgrade should be scarified ; moisture-conditioned;
and compacted to a firm, unyielding condition. Alternatively, unsuitable soils can be
overexcavated and replaced with compacted structural fill.
• Utility trench excavation and backfill: LAI anticipates that utility trenches will be excavated in
medium dense to dense outwash soils. Caving may occur in outwash soils. A heavy-duty
hydraulic excavator should be able to reach the required trench depths. A smooth -bladed
bucket should be used to remove loose and/or disturbed soil from the trench bottom. The
final trench bottom should be firm and free of roots, topsoil, lumps of silt and clay, and
organic and inorganic debris.
• Site soil: If site soils will be reused as structural fill, material larger than 6 inches in diameter
(e.g., large cobbles and boulders) should be removed or screened.
• Import structural fill: Gravel Borrow, as described in Section 9 -03.14(1) of the 2021 WSDOT
Standard Specifications, is a suitable source of import structur al fill. During periods of wet
weather, the fines content should not exceed 5 percent, based on the minus ¾-inch fraction.
• Fill placement and compaction: Structural fill should be placed on an approved subgrade that
consists of uniformly firm, unyielding, inorganic native soils or of compacted structural fill that
extends to such soils. Structural fill should be placed and compacted in accordance with the
requirements in Section 2-03.3(14)C, Method C of the 2021 WSDOT Standard Specifications.
Method A is appropriate for non -structural areas, such as landscaping. Each layer of structural
fill should be compacted to at least 95 percent of the maximum dry density, determined in
accordance with Section 2 -03.3(14)D of the 2021 WSDOT Standard Specifications.
Alternatively, the maximum dry density can be determined using ASTM standard test method
D1557.
DRAFT Landau Associates
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Longmire Development 9 August 3, 2021
• Construction dewatering: Though not observed in LAI’s test pit explorations, zones of perched
groundwater may be encountered during the wet season (typically late October through
June). Temporary excavations should be dewatered to allow construction to be completed in
the dry. Where groundwater seepage is encountered, conventional sumps and pumps should
be sufficient to dewater excavations. The contractor should be responsible for the design,
monitoring, and maintenance of dewatering systems.
• Temporary slopes: Temporary excavations should be completed in accordance with the
requirements in Section 2-09 of the 2021 WSDOT Standard Specifications. Temporary
excavations in excess of 4 ft should be shored or sloped in accordance with the requirements
outlined in Safety Standards for Construction Work, Part N (Washington Administrative Code
Chapter 296-155). The soil likely to be exposed in constructi on excavations should be
considered Type C, with a maximum allowable excavation inclination of 1½ horizontal to 1
vertical (1½H:1V).
The contractor should be responsible for actual excavation configurations and the
maintenance of safe working conditions, i ncluding temporary excavation stability. All
applicable local, state, and federal safety codes should be followed.
• Permanent slopes: Permanent cut-and-fill slopes should be no steeper than 2H:1V. This
design recommendation does not apply to stormwater pond slopes, which are typically 3H:1V
or flatter. Stormwater pond slopes should be designed in accordance with local stormwater
codes. Permanent and temporary slopes should be protected from erosion and reseeded or
revegetated as soon as practical.
Use of Thi s Technical Memorandum
Landau Associates has prepared this technical memorandum for the exclusive use of South Puget
Sound Habitat for Humanity and its design team for specific application to the Longmire Development
project in Yelm, Washington. No other p arty is entitled to rely on the information, conclusions, and
recommendations included in this document without the express written consent of Landau
Associates. Reuse of the information, conclusions, and recommendations provided herein for
extensions of t he project or for any other project, without review and authorization by Landau
Associates, shall be at the user's sole risk.
Landau Associates warrants that, within the limitations of scope, schedule, and budget, its services
have been provided in a mann er consistent with that level of skill and care ordinarily exercised by
members of the profession currently practicing in the same locality, under similar conditions as this
project. Landau Associates makes no other warranty, either express or implied.
DRAFT Landau Associates
Summary of Geotechnical Engineering Services
Longmire Development 10 August 3, 2021
Closing
We appreciate the opportunity to assist you with this project. If you have questions or comments,
please contact Lance Levine at 360 .791.3178 or at llevine@landauinc.com.
LANDAU ASSOCIATES, INC.
Lance Levine, PE
Senior Project Engineer
Calvin McCaughan, PE
Principal
LGL/CAM/mcs
[\\OLYMPIA1\PROJECTS\1592\003.010\R\LONGMIRE DEVELOPMENT DRAFT TECHNICAL MEMORANDUM 8.3.2021.DOCX]
Attachments: Figure 1. Vicinity Map
Figure 2. Site and Exploration Locati on Plan
Figure 3. Soil Classification System and Key
Figures 4–6. Logs of Test Pits TP -1 through TP-6
Figures 7–9. Grain Size Distribution
References
ASCE. 2016. Minimum Design Loads and Associated Criteria for Buildings and Other Structures
(ASCE/SEI 7-16). American Society of Civil Engineers, Structural Engineering Institute.
ASTM. 2017. Annual Book of ASTM Standards. In: Soil and Rock (I). West Conshohocken, PA: ASTM
International.
City of Yelm. 2019. Yelm Engineering Specificati ons and Standard Details. December 9.
Ecology. 2019. Stormwater Management Manual for Western Washington. Washington State
Department of Ecology. July.
ICC. 2017. 2018 International Building Code. International Code Council. August 31.
LNI. 2020. Construction Work. Chapter 296 -155 WAC; Part N. Excavation, Trenching, and Shoring.
Washington State Department of Labor and Industries. Effective October.
Schasse, H.W. 1987. Geologic Map of the Centralia Quadrangle, Washington . Washington State
Department of Natural Resources.
DRAFT Landau Associates
Summary of Geotechnical Engineering Services
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USDA NRCS. Web Soil Survey. U.S. Department of Agriculture Natural Resources Conservation Service.
Accessed July 16, 2021. Available online at:
https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm.
WSDOT. 2018. Pavement Policy. Washington State Department of Transportation. September.
WSDOT. 2020. M41-10: Standard Specifications for Road, Bridge, and Municipal Construction. 2021
Edition. Washington State Department of Transportation. September 9.
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Longmire DevelopmentYelm, Washington Vicinity Map Figure1
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Longmire Development
Yelm, Washington Site and Exploration Location Plan
Figure
2
Approximate Test Pit Location and DesignationTP-1
TP-1CULLENS STREET NWC
O
A
T
E
S
A
V
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N
U
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TP-5
TP-3
TP-4
TP-2
3Longmire Development
Yelm, Washington
1
Approximate water level at time after drilling/excavation/well
AC or PC
CLEAN SAND
FINE-GRAINED SOILPT
OH
CH
Well-graded gravel; gravel/sand mixture(s); little or no fines
MH
OL
CL
ML
SC
Field and Lab Test Data
Soil Classification System
SM
SP(Little or no fines)(More than 50% of material is smaller than No. 200 sieve size)Silty gravel; gravel/sand/silt mixture(s)
Silty sand; sand/silt mixture(s)
Clayey sand; sand/clay mixture(s)
Inorganic silt and very fine sand; rock flour; silty or clayey finesand or clayey silt with slight plasticity
Inorganic clay of low to medium plasticity; gravelly clay; sandyclay; silty clay; lean clay
Organic silt; organic, silty clay of low plasticity
Inorganic silt; micaceous or diatomaceous fine sand
Inorganic clay of high plasticity; fat clay
Organic clay of medium to high plasticity; organic silt
MAJOR
DIVISIONS
Pocket Penetrometer, tsf
Torvane, tsf
Photoionization Detector VOC screening, ppm
Moisture Content, %
Dry Density, pcf
Material smaller than No. 200 sieve, %
Grain Size - See separate figure for data
Atterberg Limits - See separate figure for data
Other Geotechnical Testing
Chemical Analysis
PP = 1.0
TV = 0.5
PID = 100
W = 10
D = 120
-200 = 60
GS
AL
GT
CA
Groundwater
Code
SAMPLER TYPE
Code Description
SW
GC
Sample Depth Interval
Recovery Depth Interval
Sample Identification Number
SAMPLE NUMBER & INTERVAL
TYPICAL
DESCRIPTIONS (2)(3)
Asphalt concrete pavement or Portland cement pavement
USCS
LETTER
SYMBOL(1)
Approximate water level at time of drilling (ATD)
a
b
c
d
e
f
g
h
i
1
2
3
4
5
Clayey gravel; gravel/sand/clay mixture(s)
GRAPHIC
SYMBOL
Drilling and Sampling Key
Description
Portion of Sample Retained
for Archive or Analysis
GM
GP
GW
Poorly graded gravel; gravel/sand mixture(s); little or no fines
Well-graded sand; gravelly sand; little or no fines
Poorly graded sand; gravelly sand; little or no fines
Peat; humus; swamp soil with high organic content
CLEAN GRAVELGRAVEL AND
GRAVELLY SOIL
(Appreciable amount of
fines)
GRAVEL WITH FINES
(Little or no fines)
(More than 50% of
coarse fraction passed
through No. 4 sieve)
SAND AND
SANDY SOIL
COARSE-GRAINED SOIL(More than 50% of
coarse fraction retained
on No. 4 sieve)
3.25-inch O.D., 2.42-inch I.D. Split Spoon
2.00-inch O.D., 1.50-inch I.D. Split Spoon
Shelby Tube
Grab Sample
Single-Tube Core Barrel
Double-Tube Core Barrel
2.50-inch O.D., 2.00-inch I.D. WSDOT
3.00-inch O.D., 2.375-inch I.D. Mod. California
Other - See text if applicable
300-lb Hammer, 30-inch Drop
140-lb Hammer, 30-inch Drop
Pushed
Vibrocore (Rotosonic/Geoprobe)
Other - See text if applicable(More than 50% of material islarger than No. 200 sieve size)SAND WITH FINES
(Appreciable amount of
fines)
HIGHLY ORGANIC SOIL
(Liquid limit greater than 50)
SILT AND CLAY
RK
DB
Rock (See Rock Classification)
(Liquid limit less than 50)
SILT AND CLAY
Wood, lumber, wood chips
GRAPHIC
SYMBOL
Construction debris, garbage
PAVEMENT
ROCK
WOOD
DEBRIS
OTHER MATERIALS TYPICAL DESCRIPTIONS
LETTER
SYMBOL
WD
> 30% and <
> 15% and <
> 5% and <
<
>
_
_
_
_
Primary Constituent:
Secondary Constituents:
Additional Constituents:
Notes: 1. USCS letter symbols correspond to symbols used by the Unified Soil Classification System and ASTM classification methods. Dual letter symbols
(e.g., SP-SM for sand or gravel) indicate soil with an estimated 5-15% fines. Multiple letter symbols (e.g., ML/CL) indicate borderline or multiple soil
classifications.
2. Soil descriptions are based on the general approach presented in the Standard Practice for Description and Identification of Soils (Visual-Manual
Procedure), outlined in ASTM D 2488. Where laboratory index testing has been conducted, soil classifications are based on the Standard Test
Method for Classification of Soils for Engineering Purposes, as outlined in ASTM D 2487.
3. Soil description terminology is based on visual estimates (in the absence of laboratory test data) of the percentages of each soil type and is defined
as follows:
4. Soil density or consistency descriptions are based on judgement using a combination of sampler penetration blow counts, drilling or excavating
conditions, field tests, and laboratory tests, as appropriate.
50% - "GRAVEL," "SAND," "SILT," "CLAY," etc.
50% - "very gravelly," "very sandy," "very silty," etc.
30% - "gravelly," "sandy," "silty," etc.
15% - "with gravel," "with sand," "with silt," etc.
5% - "with trace gravel," "with trace sand," "with trace silt," etc., or not noted.
Soil Classification System and Key
Figure
DRAFTd
d
d
SP-
SM
GP
W = 4
GS
W = 4
GS
S-1
S-2
S-3
Dark brown, gravelly, fine to coarse SAND with
silt (medium dense, damp)
(TOPSOIL)
Brown, very sandy, fine to coarse GRAVEL
(medium dense, damp)
(OUTWASH)
Minor caving
Grades to light brown and with cobbles and
boulders
Grades to with sand, dense, and moist
Severe caving
0
2
4
6
8
10
12
14
Groundwater not encountered.Elevation (ft)GROUNDWATER
Depth (ft)TP-1
Test DataGround Elevation (ft):Not Measured
Excavated By:Howards Construction & Excvtg
Logged By:LGL
Sample Number& IntervalSampler TypeSOIL PROFILE
Tracked ExcavatorExcavation Method:USCS SymbolGraphic SymbolSAMPLE DATA
Notes: 1. Stratigraphic contacts are based on field interpretations and are approximate.
2. Reference to the text of this report is necessary for a proper understanding of subsurface conditions.
3. Refer to "Soil Classification System and Key" figure for explanation of graphics and symbols.
Figure1592003.01 7/22/21 \\OLYMPIA1\PROJECTS\1592\003.010\T\1592003.010.GPJ TEST PIT LOG W/ ELEVATIONLongmire Development
Yelm, Washington Log of Test Pits 4
d
d
d
SP-
SM
GP
W = 3
GS
W = 2
GS
S-1
S-2
S-3
Dark brown, gravelly, fine to coarse SAND with
silt (medium dense, damp)
(TOPSOIL)
Brown, very sandy, fine to coarse GRAVEL
(medium dense, damp)
(OUTWASH)
Grades to light brown and with cobbles and
boulders
Minor caving
Grades to very dense
Moderate caving
Grades to brown, sandy, dense, and moist
0
2
4
6
8
10
12
14
Groundwater not encountered.Elevation (ft)GROUNDWATER
Depth (ft)TP-2
Test DataGround Elevation (ft):Not Measured
Excavated By:Howards Construction & Excvtg
Logged By:LGL
Sample Number& IntervalSampler TypeSOIL PROFILE
Tracked ExcavatorExcavation Method:USCS SymbolGraphic SymbolSAMPLE DATA
Test Pit Completed 07/06/21
Total Depth of Test Pit = 10.5 ft.
Test Pit Completed 07/06/21
Total Depth of Test Pit = 10.0 ft.
DRAFTd
d
d
SP-
SM
GP
W = 3
GS
W = 3
GS
S-1
S-2
S-3
Dark brown, gravelly, fine to coarse SAND with
silt (medium dense, damp)
(TOPSOIL)
Brown, very sandy, fine to coarse GRAVEL
(medium dense, damp)
(OUTWASH)
Grades to light brown with cobbles and
boulders
Moderate caving
Grades to sandy
Grades to brown, without boulders, dense, and
moist
0
2
4
6
8
10
12
14
Groundwater not encountered.Elevation (ft)GROUNDWATER
Depth (ft)TP-3
Test DataGround Elevation (ft):Not Measured
Excavated By:Howards Construction & Excvtg
Logged By:LGL
Sample Number& IntervalSampler TypeSOIL PROFILE
Tracked ExcavatorExcavation Method:USCS SymbolGraphic SymbolSAMPLE DATA
Notes: 1. Stratigraphic contacts are based on field interpretations and are approximate.
2. Reference to the text of this report is necessary for a proper understanding of subsurface conditions.
3. Refer to "Soil Classification System and Key" figure for explanation of graphics and symbols.
Figure1592003.01 7/22/21 \\OLYMPIA1\PROJECTS\1592\003.010\T\1592003.010.GPJ TEST PIT LOG W/ ELEVATIONLongmire Development
Yelm, Washington Log of Test Pits 5
d
d
d
d
SP-
SM
SP-
SM
GP
SP
W = 2
GS
W = 5
GS
S-1
S-2
S-3
S-4
Dark brown, gravelly, fine to coarse SAND with
silt (medium dense, damp)
(TOPSOIL)
Brown, gravelly, fine to coarse SAND with silt
(medium dense, damp)
(OUTWASH)
Grayish-brown, very sandy, fine to coarse
GRAVEL with cobbles and boulders (medium
dense, damp)
Light brown, very gravelly, fine to coarse SAND
with cobbles and boulders (dense, damp)
Moderate caving
Grades to without boulders and moist
0
2
4
6
8
10
12
14
Groundwater not encountered.Elevation (ft)GROUNDWATER
Depth (ft)TP-4
Test DataGround Elevation (ft):Not Measured
Excavated By:Howards Construction & Excvtg
Logged By:LGL
Sample Number& IntervalSampler TypeSOIL PROFILE
Tracked ExcavatorExcavation Method:USCS SymbolGraphic SymbolSAMPLE DATA
Test Pit Completed 07/06/21
Total Depth of Test Pit = 10.5 ft.
Test Pit Completed 07/06/21
Total Depth of Test Pit = 12.0 ft.
DRAFTd
d
d
SP-
SM
SP-
SM
GW
GP-
GM
W = 3
GS
W = 5
GS
S-1
S-2
S-3
Dark brown, gravelly, fine to coarse SAND with
silt (medium dense, damp)
(TOPSOIL)
Brown, gravelly, fine to coarse SAND with silt
(medium dense, damp)
(OUTWASH)
Grayish-brown, sandy, fine to coarse GRAVEL
with cobbles and boulders (medium dense,
damp)
Moderate caving
Grayish-brown, sandy, fine to coarse GRAVEL
with silt (dense, moist)
Severe caving
0
2
4
6
8
10
12
14
Groundwater not encountered.Elevation (ft)GROUNDWATER
Depth (ft)TP-5
Test DataGround Elevation (ft):Not Measured
Excavated By:Howards Construction & Excvtg
Logged By:LGL
Sample Number& IntervalSampler TypeSOIL PROFILE
Tracked ExcavatorExcavation Method:USCS SymbolGraphic SymbolSAMPLE DATA
Notes: 1. Stratigraphic contacts are based on field interpretations and are approximate.
2. Reference to the text of this report is necessary for a proper understanding of subsurface conditions.
3. Refer to "Soil Classification System and Key" figure for explanation of graphics and symbols.
Figure1592003.01 7/22/21 \\OLYMPIA1\PROJECTS\1592\003.010\T\1592003.010.GPJ TEST PIT LOG W/ ELEVATIONLongmire Development
Yelm, Washington Log of Test Pits 6
d
d
d
SP-
SM
SP-
SM
GP
W = 4
GS
S-1
S-2
S-3
Dark brown, gravelly, fine to coarse SAND with
silt (medium dense, damp)
(TOPSOIL)
Dark brown, gravelly, fine to coarse SAND with
silt and cobbles (medium dense, damp)
(OUTWASH)
Brown, very sandy, fine to coarse GRAVEL
(medium dense, moist)
Grades to with cobbles and boulders
Severe caving
Grades to gray, gravelly, and very dense
0
2
4
6
8
10
12
14
Groundwater not encountered.Elevation (ft)GROUNDWATER
Depth (ft)TP-6
Test DataGround Elevation (ft):Not Measured
Excavated By:Howards Construction & Excvtg
Logged By:LGL
Sample Number& IntervalSampler TypeSOIL PROFILE
Tracked ExcavatorExcavation Method:USCS SymbolGraphic SymbolSAMPLE DATA
Test Pit Completed 07/06/21
Total Depth of Test Pit = 10.0 ft.
Test Pit Completed 07/06/21
Total Depth of Test Pit = 10.5 ft.
DRAFT0
10
20
30
40
50
60
70
80
90
100
0.0010.010.1110100
60126 1001.5 163
Fine
U.S. Sieve Numbers
3/8 140 200
Depth
(ft)
Natural
Moisture (%)Symbol
U.S. Sieve Opening in Inches
14
Silt or ClayGravel
Unified Soil
Classification
Grain Size in MillimetersPercent Finer by Weight4 10 303/4 3 20
Sand
Hydrometer
MediumCoarseCobbles
4
Exploration
Number
408
Sample
Number
Coarse
1/2 50
Fine
6
Soil Description
GP
GP
GP
GP
GP
S-2
S-3
S-2
S-3
S-2
Very sandy, fine to coarse GRAVEL
Fine to coarse GRAVEL with sand
Very sandy, fine to coarse GRAVEL
Sandy, fine to coarse GRAVEL
Very sandy, fine to coarse GRAVEL
4
4
3
2
3
3.0
9.0
3.0
9.0
3.0
TP-1
TP-1
TP-2
TP-2
TP-3
Grain Size Distribution 7
Figure
1592003.01 7/22/21 \\OLYMPIA1\PROJECTS\1592\003.010\T\1592003.010.GPJ GRAIN SIZE FIGURE
Longmire Development
Yelm, Washington
DRAFT0
10
20
30
40
50
60
70
80
90
100
0.0010.010.1110100
60126 1001.5 163
Fine
U.S. Sieve Numbers
3/8 140 200
Depth
(ft)
Natural
Moisture (%)Symbol
U.S. Sieve Opening in Inches
14
Silt or ClayGravel
Unified Soil
Classification
Grain Size in MillimetersPercent Finer by Weight4 10 303/4 3 20
Sand
Hydrometer
MediumCoarseCobbles
4
Exploration
Number
408
Sample
Number
Coarse
1/2 50
Fine
6
Soil Description
GP
GP
SP
GW
GP-GM
S-3
S-2
S-3
S-2
S-3
Sandy, fine to coarse GRAVEL
Very sandy, fine to coarse GRAVEL
Very gravelly, fine to coarse SAND
Sandy, well-graded GRAVEL
Sandy, fine to coarse GRAVEL with silt
3
2
5
3
5
7.0
3.0
8.0
3.5
7.5
TP-3
TP-4
TP-4
TP-5
TP-5
Grain Size Distribution 8
Figure
1592003.01 7/22/21 \\OLYMPIA1\PROJECTS\1592\003.010\T\1592003.010.GPJ GRAIN SIZE FIGURE
Longmire Development
Yelm, Washington
DRAFT0
10
20
30
40
50
60
70
80
90
100
0.0010.010.1110100
60126 1001.5 163
Fine
U.S. Sieve Numbers
3/8 140 200
Depth
(ft)
Natural
Moisture (%)Symbol
U.S. Sieve Opening in Inches
14
Silt or ClayGravel
Unified Soil
Classification
Grain Size in MillimetersPercent Finer by Weight4 10 303/4 3 20
Sand
Hydrometer
MediumCoarseCobbles
4
Exploration
Number
408
Sample
Number
Coarse
1/2 50
Fine
6
Soil Description
GPS-3 Very sandy, fine to coarse GRAVEL48.0 TP-6
Grain Size Distribution 9
Figure
1592003.01 7/22/21 \\OLYMPIA1\PROJECTS\1592\003.010\T\1592003.010.GPJ GRAIN SIZE FIGURE
Longmire Development
Yelm, Washington