Report (63) RECEIVED
' G 9750 SW Nimbus Avenue JUN 2 9 Z 7
Beaverton, 97008-7172 CITY X91'TIGARD
p) 503-641-3478 f 503-644-8034 1
BUILDING DIVISION
April 18, 2016 5846 GEOTECHNICAL RPT
'
The Spanos Corporation ��c C�
10260 SW Greenburn Road, Suite 400 ---
Portland, OR 97223 l < '�
OFFICE COPY
Attention: Jared Mauch
tSUBJECT: Geotechnical Investigation
A + 0 Apartments
SW Oak Street between SW 95th Avenue and SW Hall Boulevard
Tigard,Oregon
At your request, we have updated our geotechnical investigation for the currently proposed A + 0
' Apartments in Tigard, Oregon. The Vicinity Map, Figure 1, shows the general location of the site. As you
know, GRI had previously completed a geotechnical report for the proposed apartments. The results of our
previous work can be found in our December 10, 2013, geotechnical report titled "Geotechnical
' Investigation, Ash Creek Apartments, SW Oak Street between SW 95th Avenue and SW Hall Boulevard",
prepared for DBG Oak Street, LLC. The purpose of our investigation was to evaluate subsurface conditions
at the site and develop conclusions and recommendations for earthwork and site preparation, floor
' support, subdrainage, design and construction of foundations, lateral earth pressures, pavement design,and
seismic design considerations. The investigation included subsurface explorations, laboratory testing, and
engineering analyses. This report describes the work accomplished and summarizes our conclusions and
' recommendations for design and construction of the proposed development.
PROJECT DESCRIPTION
As currently planned, the development will consist of a five-story apartment structure over one level of
parking (six stories total) and associated asphaltic concrete (AC) paved parking areas. A swimming pool
and surrounding landscaped areas will be located near the center of the development. Based on our
conversation with Enayat Schneider Engineering, Inc., the project structural engineer, we understand
column and wall loads for the structure will be on the order 450 kips and 20 kips/ft, respectively. We
anticipate the height of cuts and fills to establish site grades will generally be less than about 5 ft; however,
' the excavation for the pool will likely be on the order of 10 ft deep. We anticipate the project will be
designed using 2012 International Building Code (IBC), as adopted in the 2014 Oregon Structural Specialty
Code(OSSC).
' SITE DESCRIPTION
Topography and Surface Conditions
t The project site is located on the south side of SW Oak Street between SW 95th Avenue and SW Hall
Boulevard in Tigard, Oregon. The 3.3-acre parcel is currently occupied by single-family homes
surrounded by mature landscaping. The ground surface is relatively flat and has a gentle downward slope
to the south. The U.S. Geological Survey 7.5-minute topographic map of the Beaverton, Oregon,
Providing
dmg geotechnical and environmental consulting services since 1984
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quadrangle indicates the site is approximately elevation 180 ft (NAVD 88) at SW Oak Street. We
understand a survey has been completed for the site; however, the information is not yet available.
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Extensive wetland areas are located south of the project area.
Geology I The site is underlain by soils of the Willamette Silt Formation. In general, Willamette Silt is composed of
unconsolidated beds and lenses of fine-grained sand, silt, and clay. The silt is underlain by basalt, the
surface of which that is typically decomposed to the consistency of hard soil at depths of 5 to 23.5 ft. The
basalt generally becomes less decomposed and harder with increasing depth.
SUBSURFACE CONDITIONS I General
Subsurface materials and conditions were investigated on November 7 and 8, 2013, with nine borings,
designated B-1 through B-9. The borings were advanced to depths of 15.3 to 26.5 ft at the approximate I locations shown on the Site Plan, Figure 2. The borings indicate the site is mantled with 1.5 to 23.5 ft of
silt, which is underlain by sand and decomposed basalt to the maximum depth explored. The field
explorations and laboratory testing completed for this investigation are described in Appendix A. Logs of
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the borings are shown on Figures 1A through 9A. The terms used to describe the soils encountered in the
borings are defined in Tables 1A and 2A.
Soils I
For the purpose of discussion,the materials and soils disclosed by the explorations have been grouped into
the following categories based on their physical characteristics and engineering properties:
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1. PAVEMENT
2. SILT I 3. SAND(Decomposed BASALT)
4. BASALT
A detailed description of each soil unit and a discussion of groundwater conditions at the site are provided
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below.
1. PAVEMENT. Borings B-5 and B-9 encountered 2 in. of AC pavement at the ground surface. The AC in
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boring B-5 is underlain by silt soil; the AC in boring B-9 is underlain by 4 in. of crushed rock base course
(CRB). I 2. SILT. Gray to brown silt was encountered at the ground surface in borings B-1 through B-4 and B-6
through B-8 and beneath the pavement section in borings B-5 and B-9. The silt extends to a minimum
depth of 1.5 ft in boring B-9 and a maximum depth of 23.5 ft in boring B-4. The silt typically contains a
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trace to some clay and fine-grained sand. N-values of 0 to 12 blows/ft and Torvane shear strength values of
0.10 to 0.95 tsf indicate the relative consistency of the silt ranges from very soft to stiff and is typically
medium stiff. The natural moisture content of the silt ranges from about 23 to 42%. One-dimensional
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consolidation tests conducted on two relatively undisturbed samples of silt indicate the soil is moderately
preconsolidated and exhibits low compressibility in the preconsolidated range and moderate
compressibility in the normally consolidated range of pressures, see Figures 10A and 11A. Atterberg limits
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testing of two representative samples of silt indicate the soil has a liquid limit of 36 and 28% and
' corresponding plasticity index of 10 and 0%, which is representative of low-plasticity to non-plastic soils,
see Figure 12A.
' 3. SAND (Decomposed BASALT). A zone of sand derived from the decomposition of the underlying
basalt was encountered below the silt. The thickness of the sand ranges from 1.9 ft in boring B-4 to 6.5 ft
in boring B-1. The sand is typically fine-grained with trace to some medium- to coarse-grained sand,
' varying percentages of silt ranging from a trace of silt to silty, and a trace of fine gravel. N-values ranging
from 20 blows/ft to more than 50 blows for less than 6 in. of sampler penetration indicate the relative
density of the sand ranges from medium dense to very dense and is typically very dense. The natural
' moisture content of the sand ranges from about 20 to 44%. Borings B-1, B-3, B-5, B-6, and B-8 were
terminated in the sand at depths of 20.5 to 26.5 ft.
4. BASALT. Predominantly decomposed basalt was encountered beneath the sand in borings B-2, B-4, B-
7, and B-9. The basalt is typically weathered to the consistency of gravel in a matrix of silt, sand, and clay.
Based on N-values of 50 blows for less than 6 in. of sampler penetration, we estimate the relative rock
hardness is extremely soft (RO). Borings B-2, B-4, B-7 and B-9 were terminated in the basalt at depths of
15.3 to 26 ft.
' Groundwater
Borings B-1 through B-9 were advanced using mud-rotary drilling methods, which does not allow direct
observation of groundwater during drilling. Based on our experience with other nearby projects and
' review of published ground water maps (Snyder, 2008), and Oregon Water Resources Department well
logs in the vicinity, we anticipate the local groundwater level typically ranges from about 5 to 15 ft below
the ground surface during the normally dry, summer and fall months and can approach the ground surface
tduring the wet, winter and spring months or during periods of heavy or prolonged precipitation.
CONCLUSIONS AND RECOMMENDATIONS
General
' The site is mantled by 1.5 to 23.5 ft of silt, which is underlain by basalt which has decomposed to the
consistency of sand. Beneath the decomposed basalt, the site is underlain by predominantly decomposed,
' extremely soft basalt to the maximum depth explored (26.5 ft). In our opinion, the structural loads of the
proposed buildings can be supported by either conventional spread footings founded on ground
improvement or auger cast in place piles (ACIP). The following sections of this report provide our
conclusions and recommendations concerning site preparation and earthwork, foundation support, lateral
earth pressures, subdrainage and floor support, pavement design, and seismic design considerations.
Site Preparation and Earthwork
' All debris from the demolition of existing structures, pavement, and utilities should be removed from the
site. Excavations required to remove existing improvements below the proposed lowest floor elevation,
' including underground utilities, should be backfilled with structural fill. We anticipate stripping to a depth
of 6 to 12 in. will typically be required to remove surface vegetation; deeper excavations will be required
where large trees are removed. Upon completion of site stripping and excavation to subgrade level, the
exposed subgrade should be observed by a qualified geotechnical engineer. Any soft areas or areas of
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unsuitable material should be overexcavated to firm undisturbed soil and backfilled as described below in
the Structural Fill section of this report. '
Due to the moisture-sensitive nature of the fine-grained silt soils that mantle the site, site preparation and
earthwork phases of this project should be accomplished during the dry, summer months, typically
extending from June to mid-October. Our experience indicates the moisture content of the upper 2 to 4 ft
of the silt soils will decrease during warm, dry weather. However, below this depth, the moisture content
tends to remain relatively unchanged and well above the optimum moisture content for compaction. As a
result, the contractor must employ construction techniques that prevent or minimize disturbance and
softening of the subgrade soils. The use of scrapers for stripping and earthwork, even during dry weather,
may result in subgrade disturbance. As an alternative, a bulldozer or a trackhoe equipped with a smooth-
edged bucket could be used for stripping and excavation.
To prevent disturbance and softening of the fine-grained subgrade soils during wet weather or ground
conditions, the movement of construction traffic should be limited to granular haul roads and work pads.
In general, a minimum of 18 to 24 in. of relatively clean, granular material is required to support
concentrated construction traffic, such as dump trucks and concrete trucks, and protect the subgrade. A
12-in.-thick granular work pad should be sufficient to support occasional truck traffic and light tracked
construction equipment. It should be noted that telescoping forklifts are not considered light construction
equipment. A geotextile separation fabric placed on the exposed subgrade prior to placement and
compaction of the granular work pad may improve the performance of work pads and haul roads.
If the subgrade is disturbed during construction, soft disturbed soils should be overexcavated to firm soil
and backfilled with granular structural fill.
Excavations
We anticipate the proposed swimming pool will require an excavation of up to 10 ft below the existing site
grade. Borings B-4 and B-7, completed to the west and east, respectively, of the proposed pool, disclosed
the top of extremely soft rock is 20 ft,or more, below existing site grades. It should be noted that the depth
to rock is variable across the site,and the top of the rock was encountered at a depth of 5 ft in boring B-9 at
the east margin of the site. Based on the depth to rock encountered in borings B-4 and B-7, we anticipate
the required pool excavation will be in silt and can be completed with a large trackhoe. We anticipate the
excavation will be completed using sloped sidewalls, and our recommendations are provided below.
The method of excavation and design of excavation support are the responsibility of the subcontractor and
should conform to applicable local, state, or federal regulations. The information provided below is for the
use of our client and should not be interpreted to mean that we are assuming responsibility for the
subcontractor's actions or site safety.
Temporary excavation slopes on the order of 10 ft high will be required to construct the pool. Based on
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our evaluation of the soils disclosed by the borings, we anticipate temporary excavation slopes can be cut
to an angle of 1 H:1V. Flatter slopes may be necessary if significant seepage or running soil conditions are
encountered. In our opinion, the short-term stability of the temporary slopes will be adequate if surcharge
loads due to construction traffic, vehicle parking, material laydown, etc., are not allowed in the areas
within 10 ft of the top of the cut. In this regard, we recommend placing positive measures, such as fencing
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or barricades, along the top of the cut to prevent this area from being used for material storage, a queue
area for construction vehicles,or worker parking.
Other measures that should be considered to reduce the risk of temporary slope failure include:
1) Use visqueen to protect the cut slopes from drying out and/or surface saturation.
Provide positive drainage away from the excavation above and below the cuts.
1 2) Construct and backfill the embedded walls as soon as practical after making
excavation to minimize the amount of yielding in the cut slopes. the
' 3) Periodically monitor the area around the top of the excavation for evidence of ground
cracking.
1 It must be emphasized that following the above recommendations will not guarantee that failure of the
temporary cut slopes will not occur; however, the recommendations are intended to reduce the risk of a
major slope failure to an acceptable level. It should be realized, however, that blocks of ground and/or
1 localized slumps in the excavation slopes may tend to move into the excavation during the construction.
In our opinion, this is most likely to occur during the initial stages of the excavation and/or when the
groundwater level is the highest.
1 The groundwater level at the site will probably vary seasonally. Control of groundwater during the pool
excavation may be required depending on the time of year. In our opinion, groundwater control can be
1 accomplished using a network of temporary drainage ditches and sumps. In our opinion, problems
associated with groundwater would be minimized if excavations were made during the dry construction
season,which typically extends from June through October.
1 Structural Fill
In our opinion, on-site, organic-free, fine-grained silt, or imported sand and gravel are suitable for use in
1 constructing structural fills and to fill the pool excavation. However, fine-grained silt soils are sensitive to
moisture content and should be placed only during the dry summer and early fall months. If construction
is to proceed during the wet winter and spring months, fills should be constructed using relatively clean,
1 granular materials.
In general, approved organic-free, fine-grained soils used to construct structural fills should be placed in 9-
in.-thick lifts (loose) and compacted using a segmented-pad roller to at least 95% of the maximum dry
density as determined by ASTM D 698. The moisture content of the fine-grained silt soils at the time of
compaction should be controlled to within 3% of optimum. Some aeration and drying of the on-site silt
1 soils may be required to meet the above recommendations for compaction. Fill placed in landscaped areas
should be compacted to a minimum of 90% of ASTM D 698.
Imported granular material used to construct structural fills during periods of wet weather should consist of
1 material with a maximum size of up to 2 in. and not more than about 5% passing the No. 200 sieve
(washed analysis). Appropriate lift thicknesses will depend on the type of compaction equipment used.
For example, if hand-operated, vibratory plate compactors are used, lift thicknesses should be limited to
1 about 8 in. (loose). If backhoe-mounted vibratory plate compactors or large smooth rollers are used,
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greater lift thicknesses may be appropriate. All lifts should be compacted to at least 95% of the maximum
dry density as determined by ASTM D 698. I
All backfill placed in utility trench excavations within the limits of the buildings, walkways, and paved
areas should consist of granular structural fill as described above. The granular backfill should be I compacted to at least 95% of the aforementioned standard. Flooding or jetting the backfilled trenches with
water to achieve the recommended compaction should not be permitted.
Foundation Support
Based on our conversation with the project structural engineer, we understand the maximum column and
wall loads will be on the order of 450 kips and 20 kips/ft, respectively. In our opinion, foundation support I for the building can be provided by either conventional column-type and continuous spread footings
founded on ground improvement such as engineered aggregate piers or deep foundations such as ACIP
piles. It should be anticipated on the eastern edge of the project site, competent rock may be encountered I at depths less than 10 ft. If shallow competent rock (R1 or greater) is encountered, aggregate piers or deep
foundations may be eliminated and replaced with conventional spread and column footings. Footings
should be overexcavated to competent rock and backfilled with structural fill consisting of crushed rock I having a maximum particle size of 2 in.,at least two fractured faces, and a maximum of about 5% fines.
Engineered Aggregate Piers. To limit settlement of the structure, we recommend the column and wall
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loads of the structure be supported on spread footings supported on engineered aggregate piers or other
comparable ground improvement system. Engineered aggregate pier design is a proprietary contractor-
designed system. As such, piers should be designed to achieve less than 1 in. of total settlement and 1/2 in.
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of differential settlement at the design dead load plus live load. Piers should be installed through the upper
silt soils and embedded a minimum of 2 ft into the underlying medium dense to dense sands or tipped on
competent rock(R1 or greater).
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In general, an aggregate pier foundation system consists of creating a shaft, with or without casing, and
backfilling the excavation with crushed rock while compacting the rock in vertical lifts. Installation of
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aggregate piers may be somewhat challenging given the low fines content of the sands and the presence of
construction debris in the fill material. It should be anticipated that the aggregate piers may encounter
some perched groundwater seeping during periods of extended wet weather. As a result, it would be
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prudent for the aggregate pier contractor to assume that casing will likely be necessary.
Based on our experience, foundations constructed using the above methods in similar soil conditions
provide a maximum allowable bearing pressure of 4,000 to 7,000 psf and limit settlement to less than 1 in.
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However, further analysis will be required by the specialty contractor specializing in engineered aggregate
pier or other ground improvement system to provide the actual maximum allowable bearing capacity. All
footing excavations should be examined by the geotechnical engineer.
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Horizontal shear forces can be resisted partially or completely by frictional forces developed between the
base of spread footings and the underlying soil and by soil passive resistance. The total frictional resistance I between the footing and the soil is the normal force times the coefficient of friction between the soil and
the base of the footing. We recommend an ultimate value of 0.40 for the coefficient of friction for footings
cast on aggregate piers. The normal force is the sum of the vertical forces (dead load plus real live load). If
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additional lateral resistance is required, passive earth pressures against embedded footings can be
' computed on the basis of an equivalent fluid having a unit weight of 300 pcf in soil. This design passive
earth pressure would be applicable only if the footing is cast neat against undisturbed soil, or if backfill for
the footings is placed as granular structural fill. This value assumes the ground surface in front of the
' foundation relatively level (flatter than 5H:1 V).
Auger Cast In Place (ACIP) piles. As an alternative to engineered aggregate piers, column and wall loads
' can be supported on deep foundations such as ACIP piles. Augercast-in-place (ACIP) piles are constructed
by drilling to the required depth using a continuous-flight, hollow-stem auger supported by a crane. After
reaching design depth, high-strength grout or concrete is pumped down the stem as the auger is withdrawn
' at a controlled rate, removing the soil and forming a shaft of fluid grout or concrete extending to ground
level. Once the auger is extracted, steel reinforcement is set into the grout or concrete. Reinforcement for
ACIP piles generally consists of a single full-length bar to limit shrinkage cracking and to provide resistance
' to uplift, and a reinforcing cage in the upper portion of the pile to resist lateral loads. The length of the
reinforcing cage is specified by the structural engineer based on loading conditions.
' ACIP piles having a minimum length of 30 ft or embedded a minimum of 2 ft into competent rock (R1 or
greater) and minimum diameter of 16 in. are estimated to have an allowable compression capacity of 120
kips and tension capacity of 50 kips. ACIP piles bearing on competent rock should have a minimum
' length of 10 ft. ACIP piles should have a minimum center-to-center spacing of three pile diameters.
We recommend three augercast piles be evaluated with Pile Driving Analyzer (PDA) equipment at the
beginning of pile construction to confirm the above axial capacity.
Lateral Earth Pressures
Design lateral earth pressures for retaining and embedded walls depend on the drainage condition
provided behind the walls and the type of construction, i.e., the ability of the wall to yield. The two
possible conditions regarding drainage include providing drainage to the area behind the wall or designing
' the structure to be watertight. In the event that the structures are designed to be watertight, it should be
assumed that the water table may rise to the existing ground surface at some time during the design life of
the development. The two possible conditions regarding the ability of the wall to yield include 1) a wall
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which is laterally supported at floor level or its top, and, therefore unable to yield, and 2) a conventional
cantilevered retaining wall which yields by tilting about its base.
Assuming the backfill area will be completely drained, yielding and non-yielding walls can be designed on
' the basis of a hydrostatic pressure based on an equivalent fluid weight of 35 and 55 pcf, respectively.
Assuming the embedded walls will be undrained and watertight, yielding and non-yielding walls can be
designed on the basis of a hydrostatic pressure based on an equivalent fluid weight of 55 and 90 pcf,
respectively. Additional lateral pressures due to surcharge loads, such as vehicle loads, can be estimated
using the guidelines shown on Figure 3.
' A watertight structure, such as the swimming pool, should be designed to resist the buoyant effect,
assuming the pool is empty. The uplift force can be computed by multiplying the volume of the structure
by the unit weight of water(62.4 pcf). A common method used to resist a net uplift force is to increase the
' thickness of the base slab and/or extend the base slab beyond the sidewall of the structure. The effective
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weight of submerged backfill should be evaluated using a buoyant unit weight of 60 pcf, which assumes
that all backfill will consist of granular material compacted as recommended below. ,
To create a drained condition, we recommend placing a minimum 2-ft-thick zone of 3/4-to 1/4-in. crushed
rock with less than 2% passing the No. 200 sieve directly behind the wall. The drain rock should be
separated from silty soil by a non-woven geotextile filter fabric. The details of the wall drain are presented
on Figure 4.
To account for seismic loading, the Agusti and Sitar method (2013) was used to develop lateral earth
pressures on permanent embedded structures. Using this method, the static lateral earth pressures should
be increased by an equivalent fluid unit weight of 16 pcf for non-yielding walls and 7 pcf for yielding walls
with a level back slope. This results in a triangular distribution with the resultant acting at 1/3H up from the
base of the wall,where H is the height of the wall in feet. The lateral force induced by an earthquake is in
additional to the lateral earth pressures acting on the wall during static conditions.
Compaction procedures can significantly affect the actual lateral earth pressure. Overcompaction of the
backfill behind cast-in-place concrete walls should be avoided. In this regard, we recommend compacting
the backfill to not more than about 92% of the maximum dry density (ASTM D 698) within 5 ft of the
walls. Heavy compactors and large pieces of construction equipment should not operate within 5 ft of
embedded walls to avoid the buildup of excessive lateral pressures. Compaction close to embedded walls
should be accomplished using hand-operated,vibratory-plate compactors.
Subdrainage/Floor Support
We anticipate the finish floor elevation of the buildings will be established above the surrounding site
grades. Slab-on-grade floors that are established at or above adjacent final site grades should be underlain
by a minimum 8-in.-thick granular base course. The base course material should consist of open-graded
crushed rock of up to 1-in. maximum size with less than about 2% passing the No. 200 sieve (washed
analysis). Crushed rock of 3/4- to 1/4- in. size is often used for this purpose. To facilitate construction
activities, the drain rock section can be capped with 2 in. of 3/4-in.-minus crushed rock. All base course
and crushed rock placed beneath the slab should be compacted to at least 95% of the maximum dry
density as determined by ASTM D 698, or until well-keyed using a large, steel-drum vibratory roller. The
subgrade should be evaluated by a geotechnical engineer prior to placing the base course. Soft or
otherwise unsuitable material should be overexcavated and replaced with structural fill as described above.
In our opinion, it is appropriate to assume a coefficient of subgrade reaction of 150 pci for design of a floor
slab constructed as recommended above.
If moisture-sensitive flooring will be placed on the floor slab, it may be appropriate to install a suitable
vapor-retarding membrane beneath slab-on-grade floors. The membrane should be installed in accordance
with the manufacturer's recommendations. '
It should be anticipated that groundwater may be expected to rise to near the ground surface during the
wet,winter months or during periods of prolonged precipitation. Therefore,any embedded structure, such
as the pool, should be designed to withstand the hydrostatic pressures imposed by groundwater, or
alternatively, be provided with a subdrainage system to reduce the hydrostatic pressure.
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The recommended subdrainage system for embedded structures is shown on Figure 4. The figure shows
' peripheral subdrains to drain embedded walls and an interior granular drainage blanket beneath the pool
base which, in turn, is drained by a series of perforated pipes placed on 20-ft centers. All groundwater
collected should be drained by gravity or pumped from sumps into the storm drain system.
If a subdrain is not placed beneath the pool and it is not practical to design theant ool for the full buoyant
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effect, the pool should not be emptied during periods of high groundwater. To confirm that it is safe to
' drain the pool, it would be appropriate to install at least one observation well to permit measurement of
groundwater levels. If you elect to use this approach, GRI can provide details for a typical well installation.
' Pavement Section
We anticipate paved areas will be primarily subject to automobile traffic, with occasional heavy truck
traffic. It has been our experience with similar projects that 3 in. of AC over 8 in. of CRB is suitable for the
' support of automobile traffic and parking areas. The pavement section should consist of at least 4 in. of AC
over 12 in. of CRB in areas that will be subjected to heavy truck traffic. For areas to be paved with Portland
cement concrete(PCC), we recommend a minimum of 6 in. of PCC over 6 in. of CRB.
' The recommended pavement section should be considered a minimum thickness, and it should be
assumed that some maintenance will be required over the life of the pavement (15 to 20 years). The
' recommended section is based on the assumption that pavement construction will be accomplished during
the dry season and after construction of the building has been completed. If wet-weather pavement
construction is considered, it will likely be necessary to increase the thickness of crushed rock base course
to support construction equipment and protect the subgrade from disturbance. It should be noted that the
pavement sections may not be adequate for the support of intense, heavy construction traffic.
Properly installed drainage is an essential aspect of pavement design. All paved areas should be provided
with positive drainage to remove surface water and water within the base course. This will be particularly
important in cut sections or at low points within the paved areas, such as at catch basins. Effective methods
' to prevent saturation of the base course materials include drainage ditches in communication with and
below the base course, providing weep holes in the sidewalls of catch basins, installing subdrains in
conjunction with utility excavations, and constructing separate trench drain systems.
1 Pavement subgrade should be proof rolled with a loaded dump truck prior to and after placement of the
base course. Soft areas identified by proof rolling should be overexcavated and backfilled with structural
fill. To provide quality materials and construction practices, we recommend the pavement work conform
to Oregon Department of Transportation standards.
Seismic Considerations
GRI developed recommendations for seismic design in accordance with the 2012 International Building
Code (IBC) and 2014 Oregon Structural Specialty Code (OSSC), which was recently adopted by the State
of Oregon. We recommend using Site Class C to evaluate the seismic design of the proposed new
apartment building based on the results of the previous geotechnical investigations and review of the 2012
IBC. The 2012 IBC design methodology uses two spectral response parameters, Ss and Si, corresponding
to periods of 0.2 and 1.0 second to develop the design earthquake spectrum. The spectral response
parameters were obtained from the U.S. Geological Survey (USGS) Uniform Hazard Response Spectra
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Curves for the coordinates of 45.4433° N latitude and 122.7708° W longitude. The Ss and Si parameters
identified for the site are 0.98 and 0.43 g, respectively. The MCER-level and design-level 5% damping
response spectra parameters are tabulated below:
2012 IBC SEISMIC DESIGN RECOMMENDATIONS
Recommended
Seismic Variable Value
Site Class C '
MCER 0.2-Second Period 0.99 g
Spectral Response Acceleration,SMS
MCER 1-Second Period 0.58 g
Spectral Response Acceleration,SM,
Design 0.2-Second Period 0.66 g
Spectral Response Acceleration,SDS
Design 1-Second Period 0.39 g
Spectral Response Acceleration,SDI
Based on the subsurface conditions disclosed by the borings, we anticipate the risk of liquefaction and
significant liquefaction-induced settlement due to a MCEc-level earthquake is low. Based on the location
of known and mapped faults in the area, we anticipate the potential for fault rupture or displacement at the
site is low, unless occurring on a previously unknown or unmapped fault. The risk of lateral spreading,
landslides,tsunami,and seiche at the site is absent. 11
DESIGN REVIEW AND CONSTRUCTION SERVICES
We welcome the opportunity to review and discuss construction plans and specifications for this project as
they are being developed. In addition, GRI should be retained to review all geotechnical-related portions
of the plans and specifications to evaluate whether they are in conformance with the recommendations
provided in our report. In addition,to observe compliance with the intent of our recommendations, design
concepts, and the plans and specifications, we are of the opinion that all construction operations dealing
with earthwork and foundations should be observed by a GRI representative. Our construction-phase
services will allow for timely design changes if site conditions are encountered that are different from those
described in our report. If we do not have the opportunity to confirm our interpretations, assumptions, and
analyses during construction, we cannot be responsible for the application of our recommendations to
subsurface conditions that are different from those described in this report. 1
LIMITATIONS
This report has been prepared to aid the architect and engineer in the design of this project. The scope is
limited to the specific project and location described herein, and our description of the project represents
our understanding of the significant aspects of the project relevant to site preparation and earthwork and
design and construction of foundations, floor support, and pavements. In the event that any changes in the
design and location of the buildings as outlined in this report are planned, we should be given the
opportunity to review the changes and to modify or reaffirm the conclusions and recommendations of this
report in writing. 1
The conclusions and recommendations submitted in this report are based on the data obtained from the
borings made at the locations indicated on Figure 2 and from other sources of information discussed in this
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report. In the performance of subsurface investigations, specific information is obtained at specific
locations at specific times. However, it is acknowledged that variations in soil and rock conditions may
' exist between exploration locations. This report does not reflect any variations that may occur between
these explorations. The nature and extent of variation may not become evident until construction. If,
during construction, subsurface conditions differ from those encountered in the explorations, we should be
advised at once so that we can observe and review these conditions and reconsider our recommendations
where necessary.
Please contact the undersigned if you have any questions regarding this report.
Submitted for GRI,
0 PRO,
1� �GI9
'
c. 3,930 2
OREG N '�� 40.00/
%'%. b 449
16,1 FLW.
„egos 17/20t6,
Michael W. Reed, PE, GE
Principal Jason D. Bock, PE
Project Engineer
References
Agusti, G.C., and Sitar, N., 2013, Seismic Earth Pressures on Retaining Structures in Cohesive Soils, University of California,
' Berkeley,UCB GT 13-02.
Snyder, D.T., 2008, Estimated depth to groundwater and configuration of the water table in the Portland, Oregon area: U.S.
Geological Survey Scientific Investigations Report 2008-5059.
•RO
11
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USGS TOPOGRAPHIC MAP
BEAVERTON OREG.(2014)
LAKE OSWEG`O,OREG.(2014)
I
IQ 112 1 MILE
I
G R 0 THE SPANOS CORPORATION
ASHCREEK APARTMENTS
1
VICINITY MAP
APR.2016 JOB NO.5846 FIG. 1
I
1
< X=mH >1
I
LINE LOAD,QL STRIP LOAD,q
-"-------a
..iii//%j -----"uii/=
2\ t / A 142
I Z=nH
p
Form S 0.4:
I
Ih vh _ Qr 0.2n
NW H (0.16+n2)2 V
or Form>0.4:
t 2
MI= q (13-SING COS 2a)
ah oh = Qr 1.28m2n ah TF
H (m2+n2)2 j (13 in radians)
I
LINE LOAD PARALLEL TO WALL STRIP LOAD PARALLEL TO WALL
I
I -< X=mH >
POINT LOAD,Qp
I AA
A A
Z=nH Form 50.4:
1 WM
I
A _ c _ 1-A' ah _ Qp 0.28n2
H NW H2 (0.16+n2)3
IFor m >0.4:
a ah = Qp 1.77m2n2
h H2 (m2+n2)3
IMIL a'h=ah COS2(1.18) NOTES:
ah 1. THESE GUIDELINES APPLY TO RIGID WALLS WITH POISSON'S
A Illk �. A RATIO ASSUMED TO BE 0.5 FOR BACKFILL MATERIALS.
I O 0, O
2. LATERAL PRESSURES FROM ANY COMBINATION OF ABOVE
lah LOADS MAY BE DETERMINED BY THE PRINCIPLE OF SUPERPOSITION.
I
X=mH >
IDISTRIBUTION OF HORIZONTAL PRESSURES
I VERTICAL POINT LOAD G R 0 THE SPANOS CORPORATION
ASHCREEK APARTMENTS
I SURCHARGE-INDUCED
LATERAL PRESSURE
IAPR.2016 JOB NO.5846 FIG.3
I
SEAL WITH ON-SITE 3/4-IN.-MINUS CRUSHED ROCK WITH
I
/IMPERVIOUS MATERIAL LESS THAN 5%PASSING N0.200 SIEVE
(WASHED ANALYSIS)
SLOPE TO DRAIN
2 IN.— e P
.. CONCRETE SLAB < Q
////:
aOo • • /111\ BRFAZ
IP-4- ...., -
.. �..,••�,�.s.� VARIES
I� ' a ; �!; ��j (2 IN.MIN.) 8 IN.(MIN.)
I 1 N • .:••• I ,' . ."A'ea
4' VARIES(2 IN.MIN.)
I
RANDOM BACKFILL COMPACTED
TO ABOUT 95%OF THE MAXIMUM 2 FT °
DRY DENSITY AS DETERMINED BY (MIN.) SEE DETAIL'A'FOR TYPICAL CLEAN,CRUSHED ROCK OF UP TO 4-IN.-DIAMETER P
I
ASTM D 698 • a.. UNDERSLAB RECOMMENDATIONS ERFED ON 2 DRAIN PIPES
1-IN.SIZE WITH NOT MORE THAN ARE TYPICALLY PLACED ON 20-FT CENTERS
2%PASSING THE NO.200 SIEVE AND SLOPED TO DRAIN
(WASHED ANALYSIS)
I TEMPORARY
CONSTRUCTION
SLOPE DETAIL 'A'
d NOT TO SCALE
CLEAN,CRUSHED ROCK OF UP TO
1-IN.SIZE WITH NOT MORE THAN
I
2%PASSING THE NO.200 SIEVE .
(WASHED ANALYSIS) UNDERSLAB DRAIN
4-IN.-DIAMETER PERFORATED PLASTIC
DRAIN PIPE,SLOPE TO DRAIN
PERIMETER DRAIN
I
I
G R 0 THE SPANOS CORPORATION
I
ASHCREEK APARTMENTS
TYPICAL SUBDRAINAGE
DETAILS
APR.2016 JOB NO.5846 FIG.4
1
1
I
I
1
1
1
1
1
APPENDIX A
Field Explorations and Laboratory Testing
1
1
I
APPENDIX A
' FIELD EXPLORATIONS AND LABORATORY TESTING
' FIELD EXPLORATIONS
Subsurface materials and conditions at the site were investigated on November 7 and 8, 2013, with nine
borings, designated B-1 through B-9. The borings were advanced to depths of 15.3 to 26.5 ft at the
approximate locations shown on Figure 2. The borings were drilled with mud-rotary techniques using a
truck-mounted drill rig on November 7, and a track-mount drill rig on November 8. The rigs were
provided and operated by Western States Soil Conservation of Hubbard, Oregon. The field work was
' directed by an experienced geologist from GRI, who maintained a detailed log of the materials disclosed
during the course of the work and obtained soil samples from the borings at frequent intervals of depth.
Disturbed and undisturbed samples were obtained from the borings at 2.5- to 5-ft intervals of depth.
Disturbed samples were obtained using a standard split-spoon sampler. At the time of sampling, the
Standard Penetration Test (SPT) was conducted. This test consists of driving a standard split-spoon sampler
' into the soil a distance of 18 in. using a 140-lb hammer dropped 30 in. The number of blows required to
drive the sampler the last 12 in. is known as the standard penetration resistance, or N-value. N-values, or
blow counts, provide a measure of compactness of granular soils, such as sand, and the degree of softness
or stiffness of cohesive soils, such as clays or silts. Samples obtained in the split-spoon sampler were saved
in airtight plastic jars for further examination and physical testing in our laboratory. In addition, relatively
undisturbed 3.0-in.-diameter Shelby tube samples of the silt soil were obtained by pushing a Shelby tube
' into the undisturbed soil a distance of approximately 24 in. using the hydraulic ram of the drill rig. The soil
exposed in the ends of the Shelby tubes was examined and classified. After classification, the tubes were
sealed with rubber caps and returned to our laboratory for further classification and testing.
Logs of the borings are provided on Figures 1A through 9A. Each log provides a descriptive summary of
the types of materials encountered and notes the depths at which the materials and/or characteristics of the
' materials change. To the right of the descriptive summary, the numbers and types of samples taken during
the drilling operation are indicated. Farther to the right, N-values, moisture contents, Torvane shear
strength values, and percent material passing the No. 200 sieve are shown graphically. The terms used to
describe the soils encountered in the borings are defined in Tables 1A and 2A.
LABORATORY TESTING
General
All samples obtained from the borings were returned to our laboratory for examination and testing. The
physical characteristics were noted, and the field classifications were modified where necessary.
' The laboratory program included determinations of natural moisture content, Torvane shear strength, dry
unit weight, washed sieve analyses (percent passing the No. 200 sieve), one-dimensional consolidation
testing,and Atterberg limits. The following paragraphs describe the testing program in more detail.
' Natural Moisture Content
Natural moisture content determinations were made in conformance with ASTM 2216. The results are
shown on Figures 1A through 9A.
GR
0
A-1
I
I
Torvane Shear Strength
The approximate undrained shear strength of relatively undisturbed fine-grained soil samples was
I
determined using a Torvane shear device. The Torvane is a hand-held apparatus with vanes that are
inserted into the soil. The torque required to fail the soil in shear around the vanes is measured using a
calibrated spring. The results of the Torvane shear tests are shown on Figures 1A through 9A.
I
Dry Unit Weight
The dry unit weight, or density, of relatively undisturbed soil samples was determined in the I laboratory in substantial conformance with ASTM D 2937. The unit weight determinations are
summarized in the following table.
SUMMARY OF DRY UNIT WEIGHT DETERMINATIONS I
Natural Moisture Dry Unit
Boring Sample Depth,ft Content,% Weight,pcf Soil Type
I
B-1 S-1 3.0 28 96 SILT;trace sand and clay
B-2 S-3 7.5 34 95 Sandy SILT
B-3 S-3 8.0 36 85 SILT;trace sand and clay
I
B-4 S-2 5.5 31 94 SILT;trace sand and clay
S-5 12.7 37 88 SILT; some sand,trace clay
B-5 S-4 10.5 33 90 Sandy SILT
I
B-6 S-4 10.5 37 86 SILT; some sand,trace clay
B-7 S-3 8.0 36 88 SILT;trace sand and clay
B-8 S-2 5.5 33 90 SILT;trace sand and clay
S-5 13.5 37 89 SILT;trace sand and clay
Grain Size Analysis(Washed Sieve) I
Washed sieve analyses were performed on representative samples of the soils to assist in their classification
and evaluate liquefaction potential. The test is performed by taking a sample of known dry weight and
I
washing it over a No. 200 sieve. The material retained on the No. 200 sieve is oven-dried and re-weighed,
and the percentage of material (by weight) that passed the No. 200 sieve is calculated. The test results are
tabulated below and are shown on Figures 1A through 9A.
%Passing
Boring Sample Depth,ft No.200 Sieve Classification
B-1 S-2 4.5 88 SILT;some sand,trace clay
I
S-6 15.0 88 SILT;some sand,trace clay
B-2 S-5 12.5 82 SILT;some sand,trace clay
I
S-7 20.0 74 SILT;some sand and clay
B-3 S-4 9.5 78 SILT;some sand,trace clay
B-5 S-6 15.0 98 SILT;trace sand and clay I B-6 S-7 20.0 89 SILT;some sand,trace clay
13-7 S-4 9.5 88 SILT;some sand,trace clay
B-9 S-1 2.5 36 Silty SAND;trace gravel I
G RD A-2
I
One-Dimensional Consolidation
Two one-dimensional consolidation tests were performed in conformance with ASTM D 2435 on relatively
undisturbed samples extruded from a Shelby tube obtained from borings B-2 and B-8. The test provides
data on the compressibility of the underlying fine-grained soils, necessary for settlement studies. The test
' results are summarized on Figures 10A and 11A in the form of a curve showing percent strain versus
applied effective stress. The initial and final dry unit weights and moisture contents of the samples are also
shown on the figures.
' Atterberg Limits
Atterberg limits determinations were performed on representative soil samples in conformance with ASTM
D 4318. The results of the tests are summarized on Figure 12A.
1
1
1
GR
A-3
1
I
I
Table 1A
GUIDELINES FOR CLASSIFICATION OF SOIL
I
Description of Relative Density for Granular Soil
I
Standard Penetration Resistance
Relative Density (N-values)blows per foot Il
very loose 0-4
loose 4- 10
medium dense 10-30
I
dense 30-50
very dense over 50
Description Consistency tion of for Fine-Grained(Cohesive) Soils I
Standard Penetration Torvane I Resistance(N-values) Undrained Shear
Consistency blows per foot Strength,tsf__
very soft 2 less than 0.125
I
soft 2-4 0.125-0.25
medium stiff 4-8 0.25-0.50
stiff 8- 15 0.50- 1.0
I
very stiff 15-30 1.0-2.0
hard over 30 over 2.0
Sandy silt materials which exhibit general properties of granular
I
soils are given relative density description.
Grain-Size Classification Modifier for Subclassification
I
Boulders Percentage of
12-36 in. Other Material I Adjective In Total Sample
Cobbles
3- 12 in. clean 0-2
I
Gravel trace 2- 10
1/4-3/4 in. (fine)
3/4-3 in. (coarse) some 10-30
I
Sand sandy, silty, 30-50
No. 200- No. 40 sieve (fine) clayey,etc.
I
No. 40- No. 10 sieve (medium)
No. 10-No. 4 sieve(coarse)
Silt/Clay-pass No. 200 sieve
I
G RQ
I
I
I
Table 2A
I
GUIDELINES FOR CLASSIFICATION OF ROCK
RELATIVE ROCK WEATHERING SCALE
ITerm Field Identification
Fresh Crystals are bright. Discontinuities may show some minor surface staining. No discoloration in rock fabric.
' Slightly
Weathered Rock mass is generally fresh. Discontinuities are stained and may contain clay. Some discoloration in rock
fabric. Decomposition extends up to 1 in.into rock.
Moderately Rock mass is decomposed 50%or less. Significant portions of rock show discoloration and weathering effects.
Weathered Crystals are dull and show visible chemical alteration. Discontinuities are stained and may contain secondary
I mineral deposits.
Rock mass is more than 50%decomposed. Rock can be excavated with geologist's pick. All discontinuities
Decomposed exhibit secondary mineralization. Complete discoloration of rock fabric. Surface of core is friable and usually
pitted due to washing out of highly altered minerals by drilling water.
I
Decomposed Rock mass is completely decomposed. Original rock"fabric"may be evident. May be reduced to soil with
hand pressure.
I
RELATIVE ROCK HARDNESS SCALE
Hardness Approximate Unconfined
Term Designation Field Identification Compressive Strength
I Extremely RO Can be indented with difficulty by thumbnail. May be < 100 psi
Soft moldable or friable with finger pressure.
Very R1 Crumbles under firm blows with point of a geology pick. 100-1,000 psi
Soft Can be peeled by a pocket knife and scratched with
I
Soft R2 fingernail.
Can be peeled by a pocket knife with difficulty. Cannot 1,000-4,000 psi
be scratched with fingernail. Shallow indentation made
by firm blow of geology pick.
I Medium R3 Can be scratched by knife or pick. Specimen can be 4,000 8,000 psi
Hard fractured with a single firm blow of hammer/geology pick.
Hard R4 Can be scratched with knife or pick only with difficulty. 8,000-16,000 psi
I Several hard hammer blows required to fracture
specimen.
Very R5 Cannot be scratched by knife or sharp pick. Specimen > 16,000 psi
Hard requires many blows of hammer to fracture or chip.
IHammer rebounds after impact.
RQD AND ROCK QUALITY
I
Relation of RQD and Rock Quality Terminology for Planar Surface
RQD(Rock Description of
Quality Designation),% Rock Quality Bedding Joints and Fractures Spacing
I
0 25 Very Poor Laminated Very Close < 2 in.
25 50 Poor Thin Close 2 in.—12 in.
50-75 Fair Medium Moderately Close 12 in.—36 in.
I
75-90 Good Thick Wide 36 in. 10 ft
90 100 Excellent Massive Very Wide > 10 ft
I
GRe
I
I
I
cc STD PENETRATION RESISTANCE
U-
o
c.) CLASSIFICATION OF MATERIAL a
LL (140 LB WEIGHT,30 IN.DROP)
o A BLOWS PER FOOT
w
o a_ • MOISTURE CONTENT,%
o o SURFACE ELEVATION NOT AVAILABLE o Ct 0 50 100
I - Stiff,brown mottled rust and gray SILT;trace to some fine-grained
— sand,trace clay,12-in:thick heavily rooted zone at the ground
_ surface •
— S-1 1 .(.63
5
medium stiff below 4.5 ft —
I
- S-2 — l. 40
0
— T
S-3 1 6-
10— gray below 10 ft;trace to some day between
10and15ft S-4 T 71 4
— 1 a
soft at
— S5 I 3
I
15--r�.—J— 15.0 ID
• Medium dense,gray,silty SAND;fine grained,trace medium-to S-6 I 20 il• • ' ' •— coarse-grained sand,trace fine gravel(Decomposed Basalt)
_• •• •.
-..1 , • •
I 20—•.•• •,:• brown between 20 and 21 ft;mottled yellow and orange
•••
_•• below 20 ft
S-7 T
21.5
30
(11/8/2013)
25
' 30—
I
35—
—40
II
0 0.5 1.0
2-IN.-OD SPLIT-SPOON SAMPLER TORVANE SHEAR
II 3-IN.-OD THIN-WALLED SAMPLER STRENGTH,TSF (TONS PER FT 2)
0 PERCENT PASSING
G GRAB SAMPLE OF DRILL CUTTINGS NO.200 SIEVE(WASHED)
I
' NX CORE RUN * NO RECOVERY G R 0 BORING B-1
I-SLOTTED PVC PIPE L11Liquid Lime
V Water Level(date) Moisture Content
111 Plastic Limtt APR. 2016 JOB.NO. 5846 FIG. 1A
I
ce STD PENETRATION RESISTANCE
o CLASSIFICATION OF MATERIAL ¢ (140 LB WEIGHT,30 IN.DROP) 1
U- U o w A BLOWS PER FOOT
_ a • MOISTURE CONTENT,%
w o SURFACE ELEVATION NOT AVAILABLE o coa co 0 50 100
- Verysoft,brown mottled rust SILT;trace to some fine-to medium- 1
— graied sand,trace clay,scattered gravel to a depth of 5 ft
silo t I
5— —soft to medium stiff below 5 ft;mottled gray at 5 ft 1
— S-2 5
I
sandy at 7.5 ft — *0.15 I�
S-3 I
1
10_ brown,some sand to sandy below 10ft S 4 A4
- I
S-5 I * -
15— I
I
S6I5 f
medium stiff to stiff,some day below 17.5 ft I
I
— I —
20—T 20.3 t 0
••
-J• I
••• • •• Dense,gray SAND;fine grained,trace silt(Decomposed Basalt) S-7 I
—•• • • •.
�.• • • •
..• ••
— . ••
--• • • • •
I
—•• •• •.
•
25— • —very dense,light yellow-brown below 25 ft
_ • •• Si T •
_ 26.0 1 4::5015"
- Practical refusal on weathered basalt at 26 ft (111812013) 1
30— — 1
- I
35=
I
•
1
—40 0 0.5 1.0
I 2-IN.-OD SPLIT-SPOON SAMPLER • TORVANE SHEAR (TONS PER FT I
II STRENGTH,TSF
3-IN.-OD THIN-WALLED SAMPLER PERCENT PASSING
G GRAB SAMPLE OF DRILL CUTTINGS NO.200 SIEVE(WASHED)
I NX CORE RUN * NO RECOVERY G R fl BORING B-2
I
—SLOTTED PVC PIPE �1 Liquid Limit
V_—Water Level(date) L P�SUC Mm tune Content APR. 2016 JOB.NO. 5846 FIG. 2A
I
I
I
CD w STD PENETRATION RESISTANCE
o CLASSIFICATION OF MATERIAL ¢ (140 LB WEIGHT,30 IN.DROP)
LL J F--
U
a = z w BLOWS PER FOOT
I
o — 0 n • MOISTURE CONTENT,%
SURFACE ELEVATION NOT AVAILABLE o 0
50 100
Stiff,brown mottled gray SILT;trace day and fine-grained sand,
— 4-in.-thick heavily rooted zone at the ground surface,scattered
I
= fine roots to a depth of 5 ft
S1 I 12
I
5— —medium stiff below 5 ft �t
_ S2 I 6 )11
brown below 7.5 ft /
I
—
10-
trace to some fine-grained sand below 9.5 ft S-3
1 ii!‘
S4 5 )ir
❑
_
S-5I44 - 4
I 15 —
S-6 I 4
I
— —medium stiff to stiff,some day below 17.5 ft
1
I
20 •. Very dense,brown and gray SAND;fine grained,trace to some 19.5 `
—:• • • .. silt(Decomposed Basalt)
21.0 S-7 I 2'5015'
(11/8/2013)
_
25
' 30—
I
35—
—40
I
I 2-IN:OD SPLIT-SPOON SAMPLER • TORVANE SHEAR 0 0.5 1.0
II 3-IN.-OD THIN-WALLED SAMPLER STRENGTH,TSF (TONS PER FT 9
0 PERCENT PASSING
G GRAB SAMPLE OF DRILL CUTTINGS NO.200 SIEVE(WASHED)
I
' NX CORE RUN * NO RECOVERY
G RO BORING B-3
I—SLOTTED PVC PIPE L t Ligaid Limit
V Water Level(date) Moisture Content
I Plastic Limit APR. 2016
JOB.NO. 5846 FIG. 3A
I
i STD NRARE '
(140-LBPEETWEIGHTTION,30-IN.DROP)SISTANCE
o CLASSIFICATION OF MATERIAL15 o w BLOWS PER FOOT
i s o a • MOISTURE CONTENT,%
a.r- a
E-,-.
o co 0 50 100
o � SURFACE ELEVATION NOT AVAILABLE
_ Medium stiff,brown to gray mottled rust SILT;trace day and
— fine-grained sand,4-in.-thick heavily rooted zone at the ground
— surface,scattered gravel to a depth of 2.5 ft I
S1 I 6A 1
I
5= stiff at 5 ft 1 _ I 0.g5 •
S-2
—soft to very soft,light-brown mottled rust,trace S-3 �2 -1"--
___ some fine-grained sand below 7.5 ft — I
I
10—
I—
-- S5 X015
15 _ —medium stiff to stiff below 15 ft5 s s
1
-
20— I
I
_ S-7 I _ 11 —
— t —
— 23.5 — T''''-'''''"---,...,,,,,,
1
.• ... Very dense,brown SAND;fine grained,trace silt,black staining in
—•• • • •• joints(Decomposed Basalt) 1
25—+•••. •;'. 25. 5 = 5)I6y
Practical refusal on weathered basalt at 25.5 ft(111712013) - I
—
30—
I
35_ I
—40 0 0.5 1.0
I 2-IN.-OD SPLIT-SPOON SAMPLER • TORVANE SHEAR
STRENGTH,TSF (TONS PER FT 2)
I
II 3-IN.-OD THIN-WALLED SAMPLER ❑ PERCENT PASSING
G GRAB SAMPLE OF DRILL CUTTINGS NO.200 SIEVE(WASHED) I* NO RECOVERY II BORING B-4
' NX CORE RUN G R
I-SLOTTED PVC PIPE 1——IL—Liquid Limo
11_7_Water Level(date) L Plastic umMoisturea Content APR. 2016 JOB.NO. 5846 FIG. 4A
I
I
I W STD PENETRATION RESISTANCE
CLASSIFICATION OF MATERIAL (140 LB WEIGHT,30 IN.DROP)
UI—
_ _ " "' BLOWS PER FOOT
d S z J
I
0 — a p n • MOISTURE CONTENT,%
ct SURFACE ELEVATION NOT AVAILABLE o CC < 0
50 100
Asphaltic-concrete PAVEMENT(2 in.) j 0.2
— Medium stiff,brown to gray mottled rust SILT;trace clay and fine-
1 — grained sand
$' 14
5_ mottling decreases below 5 ft,scattered fine organic )
I
_ material at 5 ft,trace to some clay between 5 and 6 ft S-2 I6j
_ —soft,brown below 7.5 ft
I
- S3 I13
10= —sandy at 10 ft _
0.20 4
I — —trace to some sand,trace clay below 12 ft —
=
8-5 L.,...,...,„ 11 15 —
1 - �,� IC
•..—.— 18.5 / \
_• ' • •: Very dense,brown mottled black and rust SAND;fine grained, �\
20— ;: • trace silt(Decomposed Basalt)
I — 20.5 S-7 _ y
(11/7/2013) 57/5'
I
25
I —
1 30
1
1 35
I _
—40
1 I 2-IN:OD SPLIT-SPOON SAMPLER . TORVANE SHEAR 0 0.5 1.0
II 3-IN.-OD THIN-WALLED SAMPLER STRENGTH,TSF (TONS PER FT2)
0 PERCENT PASSING
G GRAB SAMPLE OF DRILL CUTTINGS NO.200 SIEVE(WASHED)
1 ' NX CORE RUN * NO RECOVERY R
I-SLOTTED PVC PIPE 1--•_, pwd Limit G R BORING B-5
Water Level(date) LL MoistLurL'
e Content
I
Plastic Limit APR. 2016
JOB.NO. 5846 FIG. 5A
I
ce STD PENETRATION RESISTANCE I< (140-LB WEIGHT 30-IN.DROP)
o CLASSIFICATION OF MATERIAL LL o w BLOWS PER FOOT
± U = z a • MOISTURE CONTENT,To
_ _
L L 100 I o
a o o CD 0 50
La � SURFACE ELEVATION NOT AVAILABLE
Stiff,brown mottled gray SILT;trace clay and fine-grained sand,
2-in.-thick heavily rooted zone at the ground surface I
S-1 112
40
5— —medium stiff below 5 ft S-2 4 ii1 TI
—brown below 7.5 ft s3 .5T
'
1
10- —very soft to soft,some sand to sandy below 10 ft 1
- S-4 I 110,1c 1
S-5 — 4 i
— I T I
15— S- 6 16 4 ___
-
I
I
2D= �, I4 lois. -- o
NN
23.0 I
—• • •
'' • Very dense,brown mottled black and rust SAND;fine grained,
• : trace silt(Decomposed Basalt)
25- •:
I
I c� STD PENETRATION RESISTANCE
0 CLASSIFICATION OF MATERIAL ¢ (140-LB WEIGHT,30 IN.DROP)
J
U F w
_ = z w BLOWS PER FOOT
a ad t- 2, a • MOISTURE CONTENT,%
I
o — o SURFACE ELEVATION NOT AVAILABLE o ce 0
50 100
Stiff,brown mottled gray SILT;some fine-grained sand,2-in.-thick
— heavily rooted zone at the ground surface,scattered roots to a
I
_ depth of 5 ft
— �, It
„ lit
5= --trace clay and fine-grained sand below 5 ft V
I = S-2 I 18
medium stiff below 7.5 ft T
I •
S-3 •
.Q.5
10
very soft,some sand at 9.5 ft;brown below 9.5 ft
S-4 _moo fj
Isoft to medium stiff below 12.5 ft
S5 I 5 i
1 151
s-6I3 j
I =
—v-•.. . . 18.5 f
—• • • ••
• Very dense,brown mottled gray SAND;fine grained,trace silt
I 20—.. • . .
(Decomposed Basalt)
._••• 1
21.0 IS-7T 3E-50//
—++++ Extremely soft(RO),black and brown BASALT;gravel-size
++++ fragments of predominantly decomposed basalt in matrix of
I
-++++ sandy silt with trace clay \
_++++ 1
—++++
25 ++++
25.5 S-8 I 516'A
I
_ (111712013)
I 30-
1
I
35-
-
I _—
—40
1 I 2-IN:OD SPLIT-SPOON SAMPLER • TORVANE SHEAR 0 0.5 1.0
II 3-IN.-OD THIN-WALLED SAMPLER STRENGTH,TSF (TONS PER FT 2)
0 PERCENT PASSING
G GRAB SAMPLE OF DRILL CUTTINGS NO.200 SIEVE(WASHED)
1 ' NX CORE RUN * NO RECOVERYG BORING B-7
I-SLOTTED PVC PIPE n-- •--i Liquid Limit j�
Water Level(date) L I—Moisture Content
I Plastic Limit APR. 2016
JOB.NO. 5846 FIG. 7A
STD PENETRATION RESISTANCE
o CLASSIFICATION OF MATERIAL ¢
(140-LB WEIGHT,30-IN.DROP)
w A BLOWS PER FOOT
F a • MOISTURE CONTENT,%
o
o c SURFACE ELEVATION NOT AVAILABLE o ( 43 0 50 100 I
Medium stiff,brown mottled gray and rust SILT;trace day and
fine-grained sand,4-in.-thick heavily rooted zone at the ground
surface I Si Ii-- ?
5—
S-2 .0.40 -- — '
- —brown,trace to some sand below 7 ft —
I
1
10 — S-4 114 •
- S-5 _ C.3(,
15— S6 5
— I
20 Very dense,brown SAND;medium grained,trace silt a3 -- ,
(Decomposed Basalt) 215 S-7 I
(111812013)
25—
1
30-
35-
40
0-35=40 0 0.5 1.0
I 2-IN.-OD SPLIT-SPOON SAMPLER • TORVANE SHEAR
STRENGTH,TSF (TONS PER FT 2)
II
3-IN.-OD THIN-WALLED SAMPLER ❑ PERCENT PASSING
G GRAB SAMPLE OF DRILL CUTTINGS NO.200 SIEVE(WASHED)
* NO RECOVERY ll BORING B-8
NX CORE RUN G R
I-SLOTTED PVC PIPE TL'L'Lpuid Limit
Water Level(date) L Pia a Lint Content APR. 2016 JOB.NO. 5846 FIG. 8A
I
I
LL STD PENETRATION RESISTANCE
o
U w
CLASSIFICATION OF MATERIAL ¢ (140 LB WEIGHT,30 IN.DROP)
I—
o "' BLOWS PER FOOT
z
a = a • MOISTURE CONTENT,%
I
o oo SURFACE ELEVATION NOTAVAILABLE ocr
0 50 100
—75rAsphalC Concrete PAVEMENT(2 in.)over crushed rock BASE 0.5
• •.\URSEti (4 in.)
J 15
,••• Stiff,brown SILT
••• •• ••
- 68
.. • I • Very dense,brown,silty SAND;fine to medium grained,trace s-1 I —T ❑
•. :• ... fine gravel
5 ' 5.0 S-2 I 5J/
I —++++ Extremely soft(RO),black and brown BASALT;gravel-size
—++++ fragments of predominantly decomposed basalt in matrix of fine-
-++++ to coarse-grained sand and gravel
++++
I -++++
-++++
-++++
10_++++ S-3 I 5J/5°A
I —++++
—+++-I-
-++++—++++
—++++
I
—++++
—++++
15— + -1- — 15.3 S-4 2 5J/3°A
(11/7/2013)
I
20
—
25
' 30—
I —
I 35—
-
-40
I 2-IN.-OD SPLIT-SPOON SAMPLER • TORVANE SHEAR 0 0.5 1.0
II 3-IN.-OD THIN-WALLED SAMPLER STRENGTH,TSF (TONS PER FT 2)
0 PERCENT PASSING
G GRAB SAMPLE OF DRILL CUTTINGS NO.200 SIEVE(WASHED)
I
' NX CORE RUN * NO RECOVERY G R BORING B-9
�1
I—SLOTTED PVC PIPE L —Liquid Limit
Water Level date Moisture Content
(date) Plastic Limit APR. 2016 JOB.NO. 5846 FIG. 9A
•
t
S
10
0
Z —
ce
H
15
1
1
20
1 -
I
25
0.01 0.1 1 10 100
STRESS, TSF
Initial
0 Location Sample Depth,ft Classification Yd,pcf MC, %
m
• B-2 S-3 8.0 Brown, sandy SILT; fine-grained sand 87 33
Ia
C7
of
1F
LO
w
a
co
a
GiRl
a .
0
CONSOLIDATION TEST
J
Q
I8 APR.2016 JOB NO.5846 FIG. 10A
1
5
mmumpium1
10
Z '
F-
1
15
1
•
1
20
1111
251
0.01
00.1 1 10 100 I
STRESS,TSF
Initial
0 Location Sample Depth,ft Classification Yd,pcf MC, %
• B-8 S-5 13.0 Brown SILT;trace fine-grained sand 90 32
0
m
0
0W
cc
w
GRI I
CONSOLIDATION TEST
APR.2016 JOB NO. 5846 FIG. 11A
I
t SYMGROUPBOL UNIFIED SOIL CLASSIFICATION GROUP UNIFIED SOIL CLASSIFICATION
FINE-GRAINED SOIL GROUPS SYMBOL FINE-GRAINED SOIL GROUPS
ORGANIC SILTS AND ORGANIC SILTY ORGANIC CLAYS OF MEDIUM TO HIGH
OL CLAYS OF LOW PLASTICITY OH PLASTICITY,ORGANIC SILTS
I
ML INORGANIC CLAYEY SILTS TO VERY FINE SANDS OF SLIGHT PLASTICITY
INORGANIC CLAYS OF LOW TO MEDIUM MH INORGANIC SILTS AND CLAYEY SILT
CL PLASTICITY CH INORGANIC CLAYS OF HIGH PLASTICITY
I
60 I 50 CH
1
40 —
0
I X
Lu0
Z
30 CL
Iu
1—
ICJ
20
MH or OH
t10 - -- —
t CL-ML
ML or OL
0
® L —
0 10 20 30 40 50 60 70 80 90 100
I
LIQUID LIMIT, %
I
Location Sample Depth,ft Classification LL PL PI MC,
• B-1 S-4 10.0 SILT; trace to some fine-grained sand and clay 36 26 10 32
- — —
Cn
N ® B-4 S-4 10.0 SILT; trace to some fine-grained sand,trace clay 28 28 NP 39
(5
aiQ
I J
ce
0
0_
C5
a
I J
LO
w
C7
Q
d
Ce
1w
co
LirRII
U
H
co
I
X PLASTICITY CHART
w
coJO
a
t APR.2016 JOB NO. 5846 FIG. 12A