HomeMy WebLinkAboutBoat Haven Sims Way expansion Geotech Report 2024.05.23ASSOearth
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Subsurface Exploration, Geologic Hazord, and
Preliminory Geotechnicol Engineering Report
WESTERN BOAT YARD EXPANSION
Port of Port Townsend, Washington
Prepared For:
REID MIDDLETON, INC.
Project No. 20240066E001
May 23,2024
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SUBSURFACE EXPLORATION, GEOLOGIC HAZARD, AND
PRELIMINARY GEOTECHNICAL ENGINEERING REPORT
WESTERN BOAT YARD EXPANSION
Port of Port Townsend, Washington
Prepared for:
Reid Middleton, Inc.
728 t34th Street SW, Suite 200
Everett, Washington 98204
Prepared by:
Associated Earth Sciences, lnc.
911 5th Avenue
Kirkland, Washington 98033
425-827-7701
May 23,2024
Project No. 20240065E001
Western Boat Yard Exponsion
Subsurface Exploration, Geologic Hozord, qnd
Prel i mi n a ry G eotech nico I E ng inee ri n g Report
Proiect and Site ConditionsPort of Port Townsend,Woshinqton
2.0 PROJECT AND SITE DESCRIPTION
The project site is located along the western extent of the Port's existing boat yard in Port
Townsend, Washington, as shown on the "Vicinity Map," Figure L. The project area is bordered
to the east by the existing boat yard and marina, to the south by Port Townsend Bay, and to the
northwest by a steep slope that ascends to West Sims Way. The existing boat yard provides
both covered and outdoor workspace for vessels of varying sizes. Vessels are transferred from
the water to the workspace by mobile boat lifts with lifting capacities ranging from 75 to
300 tons. The proposed project area is located southwest of the existing boat yard and
primarily consists of densely vegetated land with the Port's maintenance shop, gravel parking,
and covered storage area located at the southwest corner of the site.
The project area is relatively flat to gently sloping towards Port Townsend Bay with an overall
vertical relief of less than 5 feet. The central portion of the project area is undeveloped and
densely vegetated with tall grasses, shrubs, blackberry bushes, deciduous trees, evergreen
trees, and other ground cover. This area is relatively flat but small drainage ditches, swales, and
berms have created a slightly undulating surface throughout the site. An existing 18-inch
culvert is located at the northern extent of the project area that outfalls collected stormwater
to a treatment swale.
A steep slope borders the project boundary to the northwest. This slope ascends to West Sims
Way and has an overall height of about 20 feet at the eastern extent (adjacent to the existing
boat yard) and ranges up to approximately 80 feet in height at the western extent of the
project area. Slope inclinations range from approximately 60 to 85 percent. Existing site
features and Light Detection and Ranging (LIDAR)-based topographic contours are shown on
Figure 2.
We understand the Port is planning to expand the existing boat yard to the southwest and the
expanded area may cover roughly 6 acres. Existing ground surface elevations within the
proposed expansion area generally range from 8 to 10 feet with isolated topographic lows and
highs near elevation 7 feet and L2 feet, respectively. The conceptual grading plan indicates that
proposed site grades will generally be raisedby 2 to 4 feet across most of the project area and
fills up to 7 feet in height will be required in isolated low-lying areas. The project also includes
new stormwater treatment swales, potentially relocating the Larry Scott Memorial Trail to
follow the northern project boundary, and the installation/replacement of water and sewer
lines. The project may also relocate the Port's maintenance shop, but current plans indicate the
shop is to remain in its existing location. The proposed site features are shown on Figure 3.
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Subsurface Explorotion, Geologic Hazard, and
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Project and Site ConditionsPort ofPo rt Townse n d, Washi n qton
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 exploration boring logs.
The borings were continuously observed and logged by a geologist from our firm. The samples
obtained from the split-barrel sampler were classified in the field and representative portions
placed in watertight containers. The samples were then transported to our laboratory for
further visual classification and laboratory testing. The exploration logs presented in
Appendix A are based on the N-values, field observations, and drilling action.
4.0 SUBSURF E CONDITIONS
Subsurface conditions at the project site were inferred from the field explorations
accomplished for this study, our visual reconnaissance of the site, and review of selected
geologic literature. Detailed descriptions of the materials encountered in the explorations are
provided on the exploration logs in Appendix A and the regional geologic mapping of the
project site and vicinity is shown on Figure 4. Our explorations generally encountered a layer of
existing fill overlying natural beach (Holocene) sediments and pre-Fraser undifferentiated
sediments at depth. The following section presents more detailed subsurface information
organized from the shallowest (youngest) to the deepest (oldest) sediment types.
4.1 Stratigraphv
Sod/Topsoil
A surficial layer of sod and organic topsoil was encountered directly below the ground surface
in EB-l-, EB-3, and EB-4. The thickness of the organic topsoil horizon ranged from approximately
2to4 inches. Organictopsoil can be expected in the undeveloped areas onsite and this horizon
may be thicker at unexplored areas. The topsoil is not suitable for use as structural fill and
should be removed prior to construction in these areas.
Crushed Rock Aggregate (Grovel Lot Surfacing)
ln explorations EB-2 and EB-5, we encountered crushed rock aggregate that serves as the gravel
surfacing for vehicle parking and vessel storage. The crushed rock layer was approximately
4 inches thick in EB-2 and 6 inches thick in EB-5.
Fill
Directly below the sod and topsoil in EB-1, EB-3, and EB-4, and directly below the gravel lot
surfacing in EB-2 and EB-5, we encountered existing fill soils {those not naturally deposited).
The existing fill soils were variable in density and composition and extended to depths of about
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Subsurface Exploration, Geologic Hazqrd, snd
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Project ond Site ConditionsPort ofPort Townse n d, Wa sh i n gton
mapped along the slope that ascends to West Sims Way and in the upland area to the north.
The regional geologic mapping of the project site and vicinity is shown on Figure 4. The term
"modified land" refers to soil, sediment, or other geologic material that was locally reworked by
excavation and/or redistribution to modify topography. The term "fill" refers to any material
that was placed to elevate and reshape the land surface and includes engineered and
non-engineered fills. Our interpretation of the sediments encountered in our explorations is in
agreement with the regional geologic map in that we encountered fill soils overlying native
beach deposits at all locations explored.
4.3 Soil Mappine
Review of regional soils mapping (Soil Survey of Jefferson County Ared, Woshington, U.S.
Department of Agriculture [USDA], Soils Conservation Service [SCS] now referred to as Natural
Resources Conservation Service [NRCS]) on the NRCS Web Soil Survey indicates that the subject
site is predominately underlain by cut and fill land, with "rough broken land" mapped along the
northwest project boundary, Clallam gravelly sandy loam mapped along the northeast property
boundary, and coastal beach deposits mapped to the southeast. The "rough broken land"
typically consists of marine bluffs which have steep slopes greater than 50 percent. Tidal action
and storms have undermined the toe of the bluffs causing land to slide from above. The Clallam
gravelly sandy loam mapped along the northeastern project boundary and in the uplands to the
north are soils typically derived from glacial till.
Our interpretation of the near-surface sediments encountered in our explorations is generally
consistent with the regional soils mapping in that we encountered fill soils overlying native
beach deposits at all locations explored. No explorations were completed along the slope or
upland area to the north; however, we observed coastal bluffs to the west of the site that
appeared consistent with the "rough broken land" soil unit description.
4.4 Hvdrolosv
Groundwater was encountered at depth in all explorations completed for this study. Within
EB-1 through EB-5, groundwater depths at the time of drilling ranged from approximately 5.2 to
5.8 feet below existing grade. The approximate depths to groundwater at the time of drilling
are depicted on the subsurface exploration logs in Appendix A and summarized in Table 1
below. The groundwater observed at these boring locations is interpreted to be representative
of an unconfined water table aquifer underlying the site, is tidally influenced, and closely
correlates to the elevation of water in Port Townsend Bay.
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Subsurface Explorotion, Geologic Hqzqrd, ond
Prel i m i n a ry Geotech nico I E ng i n eeri ng Report
Project ond Site ConditionsPort ofPort Tow n se nd, Ws sh i n qto n
Table 2
Summary of Grain-Size Analyses
USCS = Unified Soil Classification System
Fines Content o/o = percent of total weight passing the U.S. No. 200 Sieve
Organic Matter Content
AESI also conducted an organic matter content determination on a sample of existing fill
collected from EB-3 at a depth interval of 2.5 to 4 feet (split sample from EB-3 in Table 1 above)
in accordance with ASTM D-2974. The soil sample had an organic matter content of
20.4 percent.
Exploration
Boring No.
Sample
Depth
(feet)Geologic Unit USCS Soil Description
Fines
Content
(%l
EB-3 2.5-4 Fill Gravelly SAND, some silt (SP-SM)7.5
EB-4 0-1.5 Fill Gravelly SAND, some silt (SP-SM)7.3
EB-5 0-1.s Fill Very gravelly SAND, some silt (SW-SM)10.8
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Subsurface Exploration, Geologic Hozord, and
P rel i m i n o ry Geote ch nico I E ng in ee ri n g Re port
Port ofPo rt Tow nsend, Wa sh i n gto n Geoloqic Hoza rd s a nd M itiaotio ns
The LIDAR imagery does not reveal any indications of recent catastrophic landsliding activity at
the project site; however, the map does indicate the presence of shallow scarps and hummocky
topography scattered across the slope face. There appears to be two separate scarp features
located directly north of the maintenance shop area and near the western extent of the project
boundary. The remaining areas within the limits of the proposed boat yard expansion are
relatively flat to gently sloping toward the bay and the risk for landsliding in these areas is low,
in our opinion.
It should be noted that a detailed slope stability analysis was beyond the scope of work for this
study, and the potential for deep-seated slope failures has not been evaluated' Additional
borings advanced from the top of slope would be required to evaluate the potential for
deep-seated landslide hazards affecting the site and proposed improvements.
5.2 Catch ent Berm
We recommend that the project include the construction of a catchment berm or barrier along
the toe of the slope to mitigate potential shallow debris flows and shallow slides from
impacting the expanded boat yard and stored vessels. We have not completed .a detailed
analysis of slope stability including the possible size of debris flow or shallow slide events. We
are available to provide a more detailed slope analysis depending on site planning and layout.
For preliminary planning, we recommend that a catchment berm should have a minimum
height of 4 feet and side slopes of 2H:1V (Horizontal:Vertical) or flatter on either side of the
berm's crest. The berm should be offset from the slope toe such that the berm's side slopes can
provide catchment to potential debris flows and shallow slides. We understand that the
Larry Scott Memorial Trail may be relocated to follow the northern project boundary along the
toe of the slope. The relocated trail could be supported on the catchment berm'
5.3 Stormwater Treatment Swales
We understand that two stormwater treatment swales are currently proposed along the
northern project boundary, near the toe of the steep slope. The swales should be lined with
quarry spalls and rock check dams to mitigate soil erosion that could potentially undermine the
toe and result in unstable slope conditions.
6.0 sEls MIC HAZARDS AND RECO MMENDED M GATION
The following discussion is a general assessment of seismic hazards that is intended to be useful
to the project design team in terms of understanding seismic issues, and to the structural
engineer for design.
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Subsurface Explorotion, Geologic Hazord, and
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Port of Po rt Townse nd, Wash i n gton Geologic Ha zo rd s a nd M itigotio n s
The recurrence interval of movement along this fault system is still unknown, although it is
hypothesized to be in excess of one thousand years. Due to the observed distance to suspected
fault traces, and the suspected long recurrence interval, the potential for surficial ground
rupture along the SWIFZ is considered to be low during the expected life of the proposed
improvements, in our opinion.
6.2 Liquefaction and Lateral Spreadine
Liquefaction is a process through which unconsolidated soil loses strength as a result of
vibrations, such as those which occur during a seismic event. During normal conditions, the
weight of the soil is supported by both grain-to-grain contacts and by the fluid pressure within
the pore spaces of the soil below the water table. Extreme vibratory shaking can disrupt the
grain-to-grain contact, increase the pore pressure, and result in a temporary decrease in soil
shear strength. The soil is said to be liquefied when nearly all of the weight of the soil is
supported by pore pressure alone. Liquefaction can result in deformation of the sediment and
settlement of overlying structures. Areas most susceptible to liquefaction include those areas
underlain by very soft to stiff, non-cohesive silt and very loose to medium dense, non-silty to
silty sands with low relative densities, accompanied by a shallow water table.
To evaluate the extent of liquefaction risk and estimated settlement potential during a
design-level seismic event, we performed a liquefaction hazard analysis utilizing data obtained
from our exploration borings. Our liquefaction analysis was completed with the aid of
LiquefyPro computer software Version 5.9a (2015) by CivilTech Corporation. This program
accepts input for SPT data, groundwater levels, soil unit weight, and the depth and grain-size
distribution of the sediments of concern to calculate seismically induced settlement. The
following parameters were used during the analysis:
Soil unit weights were estimated based on density of soil samples retrieved from
representative geologic u nits duri ng d ril I i ng.
Silt contents were inferred from a combination of visual and laboratory classification of
soil samples obtained from the SPT borings.
The groundwater level was assumed to be 5 feet below the existing ground surface
during earthquake shaking.
We used the Tokimatsu M-Correction method in the LiquefyPro computer software to
obtain the liquefaction-induced settlement values.
A design event is considered a magnitude 7.0 earthquake with a peak horizontal ground
acceleration of 0.639 as determined from the American Society of Civil Engineers (ASCE)
Haza rd Tool website at https://ascehaza rdtool.org.
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Port ofPo rt Town se nd, Wo sh i ngton Geologic Hozords ond Mitigations
than 0.5 seconds will need to follow Site Class "F" requirements due to liquefaction potential
and a site response analysis would be required.
7.0 EROSION HAZARDS AND RECOMMENDE D MITIGATION
Based on our explorations, the near-surface sediments across the site consist of existing fill
overlying beach deposits. The existing fill sediments underlying the site contain significant
quantities of silt and fine sand. These sediments will be susceptible to erosion and off-site
sediment transport when exposed during construction. Therefore, the project should follow
best management practices (BMPs) to mitigate erosion hazards and potential for off-site
sediment transport.
The Washington State Department of Ecology (Ecology) Construction Stormwater General
Permit (also known as the National Pollutant Discharge Elimination System [NPDES] permit)
requires weekly Temporary Erosion and Sedimentation Control (TESC) inspections and turbidity
monitoring of site runoff for all sites that are L or more acres in size that discharge stormwater
to surface waters of the state. The TESC inspections and turbidity monitoring of runoff must be
completed by a Certified Erosion and Sediment Control Lead (CESCL) for the duration of the
construction. Requirements for inspections, sampling, and reporting can be found in the
Construction Stormwater General Permit online at ecologv.wa.gov.
ln order to meet the current Ecology requirements, a properly developed, constructed, and
maintained erosion control plan consistent with local standards and best management erosion
control practices will be required for this project. lt is often necessary to make adjustments and
provide additional measures to the TESC plan in order to improve its effectiveness. Ultimately,
the success of the TESC plan depends on a proactive approach to project planning and
contractor implementation and maintenance.
To mitigate and reduce the erosion hazard and potential for off-site sediment transport, we
recommend the following:
Construction activity should be scheduled or phased as much as possible to avoid
earthwork activity during the wet season.
The winter performance of a site is dependent on a well-conceived plan for control of
site erosion and stormwater runoff. The site plan should include ground-cover measures
and staging areas. The contractor should be prepared to implement and maintain the
required measures to reduce the amount of exposed ground.
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Subsurfoce Explorotion, Geologic Hazard, and
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P re li m i na ry Desig n Recom me n d ati onsPort of Po rt Tow nse n d, Wo sh i n gto n
III. PRELIMINARY DESIGN RECOMMENDATIONS
8.0 rNTRO DUCTION
Our explorations indicate that, from a geotechnical engineering standpoint, the proposed
project is feasible provided the recommendations contained herein are properly followed. The
site is generally underlain by existing fill overlying beach deposits and pre-Fraser
undifferentiated deposits at depth, and groundwater is shallow. Based on explorations and
analyses completed to date, we have identified the following geotechnical considerations that
will impact design and construction of the project:
The existing fill was encountered to depths ranging from about 3 and 9.5 feet below
existing grade and was variable in density and composition, ranging from loose to
medium dense, slightly moist to wet, brown sand with some silt and gravel with
scattered organics, to dark brown and black, silty sand with scattered to abundant
organic debris (roots, rootlets, wood fragments, and fine organics), to gray gravel with
some sand and trace silt. Portions of the existing fillthat contain significant quantities of
organics will require overexcavation/replacement, and some areas may be difficult to
recompact to a firm and unyielding condition when exposed after clearing and grubbing.
o
o Groundwater was encountered at depths ranging from about 5.2 to 5.8 feet below
existing grade at the time of drilling. The explorations for this study were conducted in
mid-April when regional groundwater levels are typically elevated but not at seasonal
high levels, and groundwater at this site is tidally influenced. Significant dewatering
efforts may be required to control groundwater flow into excavations for underground
utilities.
The following sections provide our preliminary recommendations for site preparation,
earthwork and site grading, temporary cut slopes, structural fill, and gravel lot surfacing. We
recommend that we be allowed to review the recommendations presented in this report and
revise them, if needed, when the project design has been finalized'
9.0 SITE PREPARATION
Site preparation for the expanded boat yard area should include removal of all vegetation,
topsoil, and any other deleterious materials within areas to receive structural fill or new gravel
surfacing. Any depressions below planned final grades resulting from clearing and grubbing
activities should be backfilled with structural fill, as discussed under the "structural Fill" section
of this report.
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Subsurface Exploration, Geologic Hqzqrd, and
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that have become unstable may require remedial measures in the form of one or more of the
following:
1. Drying and recompaction. Selective drying may be accomplished by scarifying or
windrowing surficial material during extended periods of dry and warm weather.
2. Removal of affected soils to expose a suitable bearing subgrade and replacement with
compacted structural fill.
3. Mechanical stabilization with a coarse crushed aggregate such as ballast or quarry spalls
compacted into the subgrade, possibly in conjunction with a geotextile.
Consideration should be given to protecting access and staging areas with an appropriate
section of crushed rock. The crushed rock should be underlain by engineering stabilization
fabric (such as Mirafi 500X or approved equivalent) to reduce the potential of fine-grained
materials pumping up through the rock during wet weather and turning the area to mud. The
fabric will also aid in supporting construction equipment, thus reducing the amount of crushed
rock required. We recommend that at least 10 inches of rock be placed over the fabric. Crushed
rock used for access and staging areas should be of at least 2-inch size'
9.4 Overexcavation Considerations
Within our explorations, the near-surface existing fill soils generally consisted of granular
sediments (sand with variable silt and gravel content) and appear to be suitable for support of
structural fills with proper preparation; however, explorations EB-3 and EB-4 encountered
scattered to abundant quantities of organic material (roots, rootlets, wood debris, and fine
organics) directly below the ground surface to depths of 2 to 4 feet below existing grade that
may require overexcavation prior to placement of structural fill. lt is not possible to estimate
overexcavation quantities based on a set of widely spaced borings, and pockets of excessively
organic material can be expected in unexplored areas. lf a firmer assessment of overexcavation
quantities is desired for the project, we are available to assist with completing additional
explorations consisting of an array of shallow test pits with an excavator.
9.5 Potential for Contaminated Soils
During our field exploration, we encountered soils within EB-4 that contained a strong septic
odor from a depth of about 5 to 9 feet below existing grade. The source of the odor could not
be identified in the field. We recommend that this area be further explored/assessed prior to
construction.
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subgrade and backfilled with structural fill. Proof-rolling should only be attempted if soil
moisture contents are at or near optimum moisture content. Proof-rolling of wet subgrades
could result in further degradation.
lf the subgrade contains too much moisture, suitable recompaction may be difficult or
impossible to attain and should probably not be attempted. ln lieu of recompaction, the area to
receive fill should be blanketed with washed rock or quarry spalls to act as a capillary break
between the new fill and the wet subgrade. Where the exposed ground remains soft and
further overexcavation is impractical, placement of an engineering stabilization fabric may be
necessary to prevent contamination of the free-draining layer by silt migration from below.
After the exposed ground is approved, or a free-draining rock course is laid, structural fill may
be placed to attain desired grades.
10.2 Structural Fill Compaction
Structural fill is defined as non-organic soil, acceptable to the geotechnical engineer, placed
in maximum 8-inch loose lifts, with each lift being compacted to at least 95 percent of
the modified Proctor maximum dry density using ASTM D-1557 as the standard. Utility trench
backfill should be placed and compacted in accordance with applicable municipal codes
and standards. The top of the compacted fill should extend horizontally a minimum distance
of 3 feet beyond parking/storage areas before sloping down at an angle no steeper than 2H:1V.
Fill slopes should either be overbuilt and trimmed back to final grade or surface-compacted to
the specified density.
10.3 Reuse of On-Site Soils as Structural Fill
The existing fill and native beach deposits consisting primarily of sand and silty sand are suitable
for reuse in structural fill applications if such reuse is specifically allowed by project plans and
specifications, if excessively organic and any other deleterious materials are removed, and if
moisture content is adjusted to allow compaction to the specified level and to a firm and
unyielding condition. Soils in which the amount of fine-grained material (smaller than the
No. 200 sieve) is greater than approximately 5 percent (measured on the minus No. 4 sieve size)
should be considered moisture-sensitive. Most of the near-surface fill soils contained significant
silt fractions and are considered highly moisture-sensitive. These moisture-sensitive soils are
classified as "sand, some silt" (SP-SM or SW-SM), "gravel, some silt" (GP-GM), and "silty sand"
(SM) and on our boring logs in Appendix A. These soils may be difficult to reuse as structural fill
during wet weather conditions.
Additionally, construction equipment traversing the site when the silty native sediments are
very moist or wet can cause considerable disturbance. During the wetter portion of the year,
typically from October to April, we recommend assuming that the on-site soils will not be
suitable for reuse in structural fill applications. An alternative would include using only a select
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Prelimi no ry Desig n Recom me nd ati onsPort of Po rt Townse n d, Wa sh i ngton
southern drive lane of the boat yard (8th Street) may range from approximately 8 to 14 inches.
During our site reconnaissance, we observed that this drive lane section appeared to be
performing well under transient loading of the 300-ton lift.
Based on the information above, it is our opinion that the original gravel sections specified in
the referenced 1996 plans will be suitable for the expanded boat yard area provided the gravel
section is placed on properly compacted structural fill and a firm and unyielding subgrade
surface.
12 O PROJECT DESIGN AND CONST RUCTION MONITORING
We recommend that we be allowed to review the final project plans when they are completed
and to revise the recommendations presented in this report, where appropriate. We are also
available to provide geotechnical engineering and monitoring services during construction. The
integrity of earthwork, structural fills, and foundation systems depends on proper site
preparation and construction procedures. ln addition, engineering decisions may have to be
made in the field in the event that variations in subsurface conditions become apparent.
We have enjoyed working with you on this study and are confident these recommendations will
aid in the successful completion of your project. lf you should have any questions or require
further assistance, please do not hesitate to call.
Sincerely,
ASSOCIATED EARTH SCIENCES, INC.
Kirkland, Washington
Brendan u L.G
Senior Staff Geologist
(
Kurt D. Merriman, P.E.
Senior Principal Engineer
G. Bradford Drew, P.E.
Associate Engineer
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APPENDIX A
Exploration Logs
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Exploration Boring EB-1
Port of Port Townsend Western Boat Yard Expansion sheet: 1 of 1
Loesed By: BCYPort Townsend, WA Start Date:
Approved By: JHSEndiDate20240066EOOL
associatedearth sciences
in c o r p o r a t e d
Driller/Equipment: ADT / D-50 Hollow Stem Auger
Hammer Weight/Dro p: r4o#/3o"
Hole Diameter (in): 6
IGroundwater Depth ATD (ft): 5.6
Total Depth (ft): 21.s
Ground Surface Elevation (ft): =10Datum: NAVD 88n Groundwater Depth Post Drilling (ft) (Date): 0
E
OJJ
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Blows/Foot P
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Description
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Holocene Beach Deposits
Lower 12 inches: Moist, gray, fine to medium SAND, some gravel, trace silt;
occasional shell fragments (SP).
Wet, gray, fine SAND, some gravel, trace to some silt; heavily organic, silty,
sand in tip at 5 feet (SP-SM).
Wet, gray, fine SAND, trace silt, trace gravel (SP)
Wet, gray, fine SAND, trace gravel, trace silt; occasional medium sand (SP)
Holocene Beach Deposits (?)/ Pre-Fraser Undifferentiated (?)
Wet, gray, fine SAND, trace silt; massive; blow count overstated; sampler
overfilled; micaceous (SP).
As above; no gravel.
Driller adding water
L
6
4
7
6
5
7
5
4
5
3
4
5
7
6
4
13
27
29
-L2
-15
-18
-2r
-3
-6
-9
t
2
3
4
5
6
Groundwater encountered at 5.6 feet ATD. Soil heaving from 15 to 20 feet'
Tide was in.
Associated Earth Sciences, lnc.
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iatedciences
orated
Exploration Boring EB-3ASSOCearth s
incorp
Port of Port Townsend Western Boat Yard Ex nston Sheet: 1 of 1
Port WA Start Date BCY
20240066E001 Endr Date:JHS
Driller/Equipment: ADT /D-50 Hollow Stem Auger
Hammer Weight/Dro p: 140#/30"
Hole Diameter (in): 5
lGroundwater Depth ATD (ft): 5.5
Total Depth (ft): 21
Ground Surface Elevation (ft): ^:sDatUM: NAVD 88
-L Groundwater Depth Post Drilling (ft) (Date): 0
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Description
+ooooodN6{4
t \z - 4 inches 2
3
3
6
2
Fill
Slightly moist, black, organic, fine SAND, some gravel, some silt; abundant
organics (SP-SM).
Very moist, black to dark gray, gravelly, SAND, some silt; abundant rootlets
and wood debris; organic content of soil =20/o (SP-SM)'
3
4
53
3 Wet, gray, GRAVEL, some fine to medium sand, trace sil| occasional
inclusions of dark brown to black, silty, fine sand, abundant organics; broken
gravel in split spoon (GP-GM).
L t7
t2t2
6
4 As above; poor recovery; pushing on large gravel.TI
152l
9 Holocene Beach Deposits
Wet, gray, fine to medium SAND, some gravel, trace silt; rare shell fragments
(SP).
Driller adding water.
5 9
10
11
T2
15 6 Wet, gray, fine to medium SAND, trace silt; scattered shell fragments (SP)9
10
L2
18 chatter
Pre-Fraser Undifferentiated
7 Moist, light gray, silty, fine SAND, trace to some gravel; micaceous; unsorted
(sM).
2l
s0/6"
Groundwater encountered at 5.6 feet ATD
Tide was in.
21
Associated Earth Sciences, lnc.
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associatedearth sciences
incorporated
Exploration Boring EB-5
Port of Port Townse Western Boat Yard Ex nslon Sheet: 1 of 1
Port Townse WA Start Date BCY
20240066EOOt Endi Date JHS
Driller/Equipment: ADT / D-50 Hollow Stem Auger
Hammer Weight/Drop: L4o#/30"
Hole Diameter (in): 6
IGroundwater Depth ATD (ft): s.z
Total Depth (ft): 21.s
Ground Surface Elevation (ft): =10
DATUM: NAVD 88
-L Groundwater Depth Post Drilling (ft) (Date): 0
P
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Description
+oooooHNOS6
1 GravelSurfac - 5 inches 25
40
33
2
Fill
Dry to slightly moist, brown, very gravelly, fine to coarse SAND, some silU
broken gravel in tip of spoon; blow counts overstated (SW-SM).
Dry to slightly moist, brown to tan, very gravelly, SAND, some silt; broken
gravel in spoon; blow counts may be overstated (SW-SM).
40
38
20
3 Upper 9 inches: Wet, gray, fine SAND, trace silt (SP)'
Lower 9 inches: Black organic soil with layer (1.5 inches thick) of brown, silty,
fine SAND, some gravel (SM).
Water added.
Wet, brownish gray, gravelly, fine SAND, some silt; increase in gravel with
depth; broken gravel in spoon, blow counts overstated (SP-SM).
I tI
1
5
4 9
10
12
9
5
Holocene Beach Deposits
Wet, gray, fine SAND, some gravel, trace silt; scattered to abundant shells
(SP).
Driller adding water.
5
9
!7
t2
15 6 Poor recovery, trace amounts of sand in sampler L2
76
22
18
Wet, gray, fine SAND, some gravel, trace silt; scattered to abundant shells
(sP).
91l
72
Groundwater encountered at 5.2 feet ATD
Tide was in.
2t
7
Associated Earth Sciences, lnc.
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Particle Size Distribution Report
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100
90
80
70
60
50
40
30
20
10
0 10 0.01
GRAIN SIZE - mm.
Vo +3"% Gravel % Sand % Fines
Coarse Fine Coarse Medium Fine sitr Clay
0.0 16.6 9.0 3.4 17.8 45.7 7.5
(no specification provided)
Location: OnsiteSamole Number: EB-3
Date Sampled: 4-15-2024
Deoth:2.5-4
TEST RESULTS
Opening
Size
Percent
Finer
Spec.*
(Percent)
Pass?
(X=Fail)
1"
314"
s/8"
L12"
3/8"
#4
#8
#10
#20
#40
#60
#100
#200
#270
100.0
83.4
83.4
80.8
79.2
74.4
71.7
71.0
61.5
53.2
2t.2
12.4
7.5
6.t
Material DescriPtion
gravelly SAND some silt
PL= NP
Atterberg Limits (ASTM D 4318)LL- NV Pl=
USCS (D 24871=
Dso= 22-1419
Dso= 0.4ol lDlo= 0.1077
ClassificationSP-SM AASHTO (M 145)= A-3
Coefficients
D85= 20.1334
D3o= 0.2941
Cu= 4.66
Remarks
D6o= 0.5017D{s= 0'2017cc= 1'60
Date Received:. 5 -7 -2024 Date Tested:. 5-10-2024
Tested By:FEW
Ghecked By:BCY/BD
Title
associatedearth sciences
incorporated
Client: Reid Middleton
Project: Port of Port Townsend Westem Boat Yard Expansion
Proiect No: LO24OO66EOOI Fioure
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Particle Size Distribution Report
ca
ON
a
S c.E .=:N S
.E o ooooooo$oo{@rFN+++***,E
@
EIUzltFzuJ()ttu
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100
90
80
70
60
50
40
30
20
10
0 10 0.1
GRAIN SIZE - mm.
Vo +3"7o Gravel % Sand % Fines
Coarse Fine Coarse Medium Fine silt Glav
0.0 2.0 34.1 17.8 19.0 16.3 10.8
(no specification provided)
Location: OnsiteSamole Number: EB-5 Deoth:0'-1.5 DateSampled: 4-15-2024
TEST RESULTS
Opening
Size
Percent
Finer
Spec.*
(Percent)
Pass?
(X=Fail)
1.5"l"
314"
s18"
L12"
318"
#4
#8
#10
#20
#40
#60
#100
#200
#270
100.0
98.0
98.0
94.8
90.8
84.2
63.9
48.7
46.r
34.5
27.1
21.4
16.0
10.8
9.6
Material Description
very gravelly SAND some silt
PL= NP
Atterberg Limits (ASTM D 4318)
LL= NV Pl=
USCS (D 24871=
Glassification
SW-SM AASHTO
Coefficients
D85= 9'8103
Dgo= 0.5615Cu= 68'48
Remarks
(M 145)= A-l-a
Dso= 12-2126
Dso= 2-5552Dlo= 0.0599
Dso= 4'1034
D15= 0.1349cc= 1.28
Date Received: 5-7-2024 Date Tested: 5-10-2024
Tested By:FEW
Checked By:BCY/BD
Title:
associatedearth sciences
incorporated
Client: Reid Middleton
Project: Port of Port Townsend Westem Boat Yard Expansion
Proier:fNo: ).M4OO66F.OO1 Fiqure
APPENDIX C
Liquefaction Analysis Results
LIQUEFACTION ANALYSIS
Port of Port Townsend Western Boat Yard Expansion
Hote No.=EB-2 Water Depth=S ft Surface Elev'=l0 Magnitude=7.0
Acceleration=0.639
Shear Stress Ratio
0
Faclor of Safety1 01 5
Settlement
0 (in.)
Soil Description Raw Unit Fines
SPT Weioht %e 11d510
I 110 5
5 17 't20 10
17 125 7
10 17 125 7
15 15 115 5
20 15 125 5
csR fs1_
Shaded Zone has Liquefaction Potential Unsaturat.
Note: SPT N-values outlined in red were adjusted to account for
25 overstated blow counts due to soil heave or elevated gravel content.
30
35
t
E
=
==
fs1=1 S = 3.11 in.
Fiil
Beach Deposits
Ee
oo
:>t;
af
o6!
oo
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oI.Fo
6J
CivilTech Gorporation Plate A-1
LIQUEFACTION ANALYSIS
Port of Port Townsend Western Boat Yard Expansion
Hole No.=EB-4 Water Depth=5 ft Surtace Elev'=9 Magnitude=7.0
Acceleration=0.639
Shear Stress Ratio
0
Factor of Safety1 01 5
Settlement Soil Description Raw Unit Fines
0 10 SPT
23
Weioht %12{ 7
18 120 5
5 5 105 5
12 110 5
10 19 ',120 5
15 67 125 NoLq
20 50 125 NoLq
cSR fs1-
Shaded Zone has Liquefaction Potential Unsaturat.
25
30
35
fs'l=1
Fiil
Beach Deposits
Pre-Fraser Undifferentiated
S = 1.40 in
EoqEo
'q;l
@f
oo
=
@
oF
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II
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6f
CivilTech Gorporation Plate A-1