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DEC 16 2015
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GEOTECHNICAL REPORT
SW Hawk's Beard Apartments
SW Scholls Ferry Road and SW 135th Avenue
Tigard, Oregon
Project No. T-7184
Terra Associates, Inc.
Prepared for:
Holland Development
Vancouver, Washington
March 13, 2015
I
TERRA ASSOCIATES, Inc.
Consultants in Geotechnical Engineering, Geology
and
Environmental Earth Sciences
March 13,2015
Project No.T-7184
Mr.Brenner Daniels
Holland Development
1111 Main Street, Suite 700
Vancouver,Washington 98660
Subject: Geotechnical Report
SW Hawk's Beard Apartments
SW Scholls Ferry Road and SW 135th Avenue
Tigard,Oregon
Dear Mr.Daniels:
As requested,we conducted a geotechnical engineering study for the subject project. The attached report presents
our findings and recommendations for the geotechnical aspects of project design and construction.
Our field exploration indicates the site is underlain primarily by medium dense silt deposits. We observed
localized,light groundwater seepage at a depth of about 7.5 feet in one of the 12 test pits.
In our opinion,there are no geotechnical conditions that would preclude the planned development. Structures can
be supported by conventional spread footings bearing on competent native soils underlying the surface organic
soils or on structural fill placed on the competent native soils. Floor slabs and pavements can be similarly
supported. The native silt soils are very sensitive to moisture and will require careful control of moisture during
construction to facilitate adequate compaction, and measures to protect finished subgrades from disturbance
during periods of wet weather.
Detailed recommendations addressing these issues and other geotechnical design considerations are presented in
the attached report. We trust the information presented is sufficient for your current needs. If you have any
questions or require additional information,please call.
Sincerely yours,
TERRA ASSOCIATES,INC.
John . "4 ft-1 .� .'
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Proj: � 7 ger V /
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Principal °GORE SC'
EXPIRATION DATE: /sQ)1 c,
12525 Willows Road NE,Suite 101, Kirkland,Washington 98034
Phone(425)821-7777 • Fax(425)821-4334
1
TABLE OF CONTENTS
Page No.
1.0 Project Description 1
2.0 Scope of Work 1
3.0 Site Conditions 2
3.1 Surface 2
3.2 Soils 2
3.3 Groundwater 2
3.4 Seismic Design Parameters 2
4.0 Discussion and Recommendations 3
4.1 General 3
4.2 Site Preparation and Grading 3
4.3 Excavations 5
4.4 Foundations 5
4.5 Slab-on-Grade Floors 6
4.6 Lateral Earth Pressures for Below-Grade Walls 6
4.7 Drainage 6
4.8 Utilities 7
4.9 Pavements 7
5.0 Additional Services 8
6.0 Limitations 8
Figures
Vicinity Map Figure 1
Exploration Location Plan Figure 2
Typical Wall Drainage Detail Figure 3
Appendices
Field Exploration and Laboratory Testing Appendix A
Geotechnical Report
SW Hawk's Beard Apartments
SW Scholls Ferry Road and SW 135th Avenue
Tigard, Oregon
1.0 PROJECT DESCRIPTION
The proposed project is a residential development. Site development and building plans are currently unavailable;
however, it is our understanding that the buildings will be three-story, wood-frame structures with their main
floors constructed at grade. Associated site improvements will include site utilities and paved access and parking
areas.
The recommendations contained in the following sections of this report are based on our understanding of the
above design features. We should review design drawings as they become available to verify that our
recommendations have been properly interpreted and incorporated into project design and to amend or
supplement our recommendations, if required.
2.0 SCOPE OF WORK
We explored subsurface conditions at the site by observing soil conditions in 12 test pits excavated to maximum
depths ranging from about 9 to 10 feet below existing surface grades using a track-mounted excavator. Using the
results of our field study and laboratory testing, analyses were undertaken to develop geotechnical
recommendations for project design and construction. Specifically,this report addresses the following:
• Soil and groundwater conditions
• Seismic design parameters per the current International Building Code(IBC)
• Site preparation and grading
• Excavations
• Foundations
• Lateral earth pressures for design of below-grade walls
• Slab-on-grade floors
• Subsurface drainage
• Utilities
• Pavements
It should be noted that recommendations outlined in this report regarding drainage are associated with soil
strength, design earth pressures, erosion,and stability. Design and performance issues with respect to moisture as
it relates to the structure environment (i.e., humidity, mildew, mold) is beyond Terra Associates' purview. A
building envelope specialist or contactor should be consulted to address these issues,as needed.
March 13,2015
Project No.T-7184
3.0 SITE CONDITIONS
3.1 Surface
The site is an approximately 10.5-acre parcel located southeast of and adjacent to the intersection of SW Scholls
Ferry Road and SW 135th Avenue in Tigard,Oregon. The approximate location of the site is shown on Figure 1.
Site topography is relatively flat with a gentle grade down to the south and west. Site vegetation consists
primarily of mature deciduous trees with grass and brush undergrowth. The trees at the site are planted in a grid
pattern approximately ten feet on center. Two localized areas in the northeastern portion of the site have not been
planted with trees and are vegetated only with grasses and brush.
3.2 Soils
The soils observed in our test pits generally consist of about one inch of sod or forest duff and topsoil overlying
native,brown,silt to silt with sand that is interpreted to be Pleistocene catastrophic flood deposits. The native silt
deposits are generally medium dense, moist, and mottled in the upper seven feet, and become medium dense to
dense and moist with localized wet zones below that depth.
The Generalized geologic map of the Willamette lowland by M. W. Gannett and R. R. Caldwell (1998) shows the
site soils consisting of alluvium and glacial-outburst flood sediments (Qs). The silt deposits observed in the test
pits are generally consistent with glacial-outburst flood deposits.
Detailed descriptions of the subsurface conditions observed in our site explorations are presented on the Test Pit
Logs in Appendix A. The approximate test pit locations are shown on Figure 2.
3.3 Groundwater
We observed light groundwater seepage approximately 7.5 feet below the ground surface in Test Pit TP-1. The
seepage appeared temporarily as a stream squirting from a localized point source on the side of the test pit before
dying out after about ten seconds of flow.
3.4 Seismic Design Parameters
Based on the site soil conditions and our knowledge of the area geology, per Chapter 16 of the 2012 International
Building Code (IBC), site class "D" should be used in structural design. Based on this site class, in accordance
with the 2012 IBC,the following parameters should be used in computing seismic forces:
Seismic Design Parameters(IBC 2012)
Spectral response acceleration(Short Period), SMS 1.075 g
Spectral response acceleration(1 —Second Period),SM, 0.668 g
Five percent damped.2 second period, SDS 0.717 g
Five percent damped 1.0 second period, SDI 0.445 g
Values determined using the United States Geological Survey (USGS) Ground Motion Parameter Calculator
accessed on March 9, 2015 at the web site http://earthquake.usgs.gov/designmaps/us/application.php.
Page No. 2
March 13,2015
Project No.T-7184
4.0 DISCUSSION AND RECOMMENDATIONS
4.1 General
Based on our study, there are no geotechnical conditions that would preclude the planned development. The
buildings associated with the project can be supported on conventional spread footings bearing on competent
native soils underlying the surficial organic soils or on structural fill placed on a competent native soil subgrade.
Floor slabs and pavements can be similarly supported.
The site soils consist predominantly of silt and will require careful control of the soil moisture content to
adequately compact as structural fill. As such, the ability to use soils from site excavations as structural fill will
depend on the natural soil moisture content, the prevailing weather conditions at the time of construction, and the
ability of the contractor to properly moisture condition the soil. During the normally dry summer months, the
contractor should be prepared to dry soils that are wet of optimum by aeration. Alternatively, stabilizing the
moisture in the native soil with cement or lime can be considered. Moisture conditioning of soils that are dry of
optimum would require the addition of water to the soils and thoroughly blending the material prior to
compaction. If grading activities will take place during the winter season, the contractor should be prepared to
import clean granular material for use as structural fill and backfill.
Undisturbed bearing surfaces composed of native soil or structural fill derived from the fine-grained native soils
would provide suitable support for conventional spread footing foundations,floor slabs, and pavements; however,
the soils will be easily disturbed by normal construction activity,particularly when wet. If disturbed,the soil will
not be suitable for support, and the affected material would need to be removed with the foundations lowered to
obtain support on an undisturbed soil subgrade. Alternatively, the soils can be removed and grade restored with
structural fill. To reduce the potential for subgrade disturbance, particularly during wet weather, consideration
should be given to placing a six-inch layer of one- to two-inch sized crushed rock or a four-inch layer of lean
concrete on completed subgrades to serve as a working surface.
Detailed recommendations regarding these issues and other geotechnical design considerations are provided in the
following sections of this report. These recommendations should be incorporated into the final design drawings
and construction specifications.
4.2 Site Preparation and Grading
To prepare the site for construction, all vegetation,organic surface soils, and other deleterious materials should be
stripped and removed from the site. We expect surface stripping depths of about two to three inches will be
required to remove the organic surficial soils. Stripped vegetation debris should be removed from the site.
Organic soils will not be suitable for use as structural fill, but may be used for limited depths in nonstructural
areas or for landscaping purposes.
Page No. 3
March 13, 2015
Project No.T-7184
Once clearing and stripping operations are complete, cut and fill operations can be initiated to establish desired
grades. Prior to placing fill, all exposed bearing surfaces should be observed by a representative of Terra
Associates to verify soil conditions are as expected and suitable for support of new fill. Our representative may
request a proofroll using heavy rubber-tired equipment to determine if any isolated soft and yielding areas are
present. If excessively yielding areas are observed, and they cannot be stabilized in place by compaction, the
affected soils should be excavated and removed to firm bearing and grade restored with new structural fill.
Beneath embankment fills and pavement subgrades, if the depth of excavation to remove unstable soils is
excessive, we recommend placing a geotextile fabric such as Mirafi 500X, or equivalent, beneath the fill. Our
experience has shown that, in general, a minimum of 18 inches of a clean, granular structural fill placed and
compacted over the geotextile fabric should establish a stable bearing surface.
Our study indicates that the native soils consist predominantly of silt and will be difficult to compact as structural
fill when too wet or too dry. Accordingly, the ability to use these native soils from site excavations as structural
fill will depend on their moisture content and the prevailing weather conditions when site grading activities take
place. Native soils that are too wet to properly compact could be dried by aeration during dry weather conditions
or mixed with an additive such as lime or Portland cement to reduce and stabilize the soil's moisture content. If
soil amendment products are used, additional Temporary Erosion and Sedimentation Control (TESC) BMPs will
need to be implemented to mitigate potential impacts to stormwater runoff associated with possible elevated pH
levels.
If grading activities are planned during the wet winter months, or if they extend into fall and winter, the owner
should be prepared to import wet weather structural fill. For this purpose, we recommend importing a granular
soil that meets the following grading requirements:
U.S. Sieve Size Percent Passing
6 inches 100
No.4 75 maximum
No. 200 5 maximum*
*Based on the 3/4-inch fraction.
Prior to use,Terra Associates, Inc.should examine and test all materials planned to be imported to the site for use
as structural fill.
Structural fill should be placed in uniform loose layers not exceeding 12 inches and compacted to a minimum of
95 percent of the soil's maximum dry density, as determined by American Society for Testing and Materials
(ASTM)Test Designation D-698 (Standard Proctor). The moisture content of the soil at the time of compaction
should be within two percent of its optimum, as determined by this ASTM standard. In nonstructural areas, the
degree of compaction can be reduced to 90 percent.
Page No.4
March 13,2015
Project No.T-7184
4.3 Excavations
All excavations at the site associated with confined spaces, such as lower building level retaining walls, must be
completed in accordance with local, state, and federal requirements. Based on regulations outlined by the
Occupational Safety and Health Administration (OSHA), the site soils would be classified as Type C soils.
Accordingly, temporary excavation slopes in Type C soils should be graded to an inclination of 1.5:1
(Horizontal:Vertical) or flatter. All exposed slope faces should be covered with a durable reinforced plastic
membrane during construction to prevent slope raveling and rutting during periods of precipitation. Properly
designed and installed shoring trench boxes can be used to support utility trench excavations where required.
Based on our field observations, groundwater seepage may be encountered in excavations extending below a
depth of approximately seven feet, especially during the winter and spring months. We expect that the volume of
water and rate of flow of any seepage into site excavations will be relatively minor and would not be expected to
adversely impact the stability of the excavation when completed, as described above. We anticipate that
conventional sump pumping procedures along with a system of collection trenches should be capable of
maintaining a relatively dry excavation for construction purposes.
This information is provided solely for the benefit of the owner and other design consultants, and should not be
construed to imply that Terra Associates, Inc. assumes responsibility for job site safety. It is understood that job
site safety is the sole responsibility of the project contractor.
4.4 Foundations
Structures may be supported on conventional spread footing foundations bearing on competent native soils or on
structural fills placed above these native soils. Foundation subgrades should be prepared, as recommended in
Section 4.2 of this report.
Perimeter foundations exposed to the weather should bear at a minimum depth of 1.5 feet below final exterior
grades for frost protection. Interior foundations can be constructed at any convenient depth below the floor slab.
We recommend designing foundations for a net allowable bearing capacity of 2,500 pounds per square foot (psf).
For short-term loads, such as wind and seismic, a one-third increase in this allowable capacity can be used in
design. With the anticipated loads and this bearing stress applied, building settlements should be less than one
inch total and one-half inch differential.
For designing foundations to resist lateral loads, a base friction coefficient of .3 can be used. Passive earth
pressure acting on the sides of the footings may also be considered. We recommend calculating this lateral
resistance using an equivalent fluid weight of 300 pounds per cubic foot (pcf). We recommend not including the
upper 12 inches of soil in this computation because they can be affected by weather or disturbed by future grading
activity. This value assumes the foundations will be constructed neat against competent native soil or the
excavations are backfilled with structural fill, as described in Section 4.2 of this report. The recommended
passive and friction values include a safety factor of 1.5.
Page No. 5
March 13, 2015
Project No.T-7184
4.5 Slab-on-Grade Floors
Slab-on-grade floors may be supported on a subgrade prepared as recommended in Section 4.2 of this report.
Immediately below the floor slab, we recommend placing a four-inch thick capillary break layer composed of
clean, coarse sand or fine gravel that has less than three percent passing the No. 200 sieve. This material will
reduce the potential for upward capillary movement of water through the underlying soil and subsequent wetting
of the floor slab.
The capillary break layer will not prevent moisture intrusion through the slab caused by water vapor transmission.
Where moisture by vapor transmission is undesirable, such as covered floor areas,a common practice is to place a
durable plastic membrane on the capillary break layer and then cover the membrane with a layer of clean sand or
fine gravel to protect it from damage during construction, and aid in uniform curing of the concrete slab. It
should be noted that if the sand or gravel layer overlying the membrane is saturated prior to pouring the slab, it
will be ineffective in assisting uniform curing of the slab and can actually serve as a water supply for moisture
seeping through the slab and affecting floor coverings. Therefore, in our opinion, covering the membrane with a
layer of sand or gravel should be avoided if floor slab construction occurs during the wet winter months and the
layer cannot be effectively drained.
4.6 Lateral Earth Pressures for Below-Grade Walls
The magnitude of earth pressures developing on below-grade walls will depend on the quality and compaction of
the wall backfill. We recommend placing and compacting wall backfill as structural fill, as described in Section
4.2 of this report. To prevent overstressing the walls during backfilling, heavy construction machinery should not
be operated within five feet of the wall. Wall backfill in this zone should be compacted with hand-operated
equipment. To prevent hydrostatic pressure development, wall drainage must also be installed. A typical wall
drainage detail is shown on Figure 3.
With wall backfill placed and compacted as recommended, and drainage properly installed, we recommend
designing unrestrained walls for an active earth pressure equivalent to a fluid weighing 35 pounds per cubic foot
(pcf). For restrained walls, an additional uniform load of 100 psf should be added to the 35 pcf. To account for
typical traffic surcharge loading, the walls can be designed for an additional imaginary height of two feet (two-
foot soil surcharge). For evaluation of wall performance under seismic loading, a uniform pressure equivalent to
8H psf, where H is the height of the below-grade portion of the wall should be applied in addition to the static
lateral earth pressure. These values assume a horizontal backfill condition and that no other surcharge loading,
sloping embankments, or adjacent buildings will act on the wall. If such conditions exist, then the imposed
loading must be included in the wall design. Friction at the base of foundations and passive earth pressure will
provide resistance to these lateral loads. Values for these parameters are provided in Section 4.4 of this report.
4.7 Drainage
Surface
Final exterior grades should promote free and positive drainage away from the building areas. We recommend
providing a positive drainage gradient away from the building perimeter. If a positive gradient cannot be
provided provisions for collection and disposal of surface water adjacent to the structure should be made.
Page No. 6
March 13, 2015
Project No.T-7184
Surface water from developed areas must not be allowed to flow in an uncontrolled and concentrated manner over
the crests of site slopes and embankments. Surface water should be directed away from the slope crests to a point
of collection and controlled discharge. If site grades do not allow for directing surface water away from the
slopes,then the water should be collected and tightlined to an approved point of controlled discharge.
Subsurface
We recommend installing a continuous drain along the outside lower edge of the perimeter building foundations.
The drains can be laid to grade at an invert elevation equivalent to the bottom of footing grade. The drains can
consist of four-inch diameter perforated PVC pipe that is enveloped in washed 'A-to 3%-inch gravel-sized drainage
aggregate. The aggregate should extend six inches above and to the sides of the pipe. The foundation drains and
roof downspouts should be tightlined separately to an approved point of controlled discharge. All drains should
be provided with cleanouts at easily accessible locations. These cleanouts should be serviced at least once each
year.
4.8 Utilities
Utility pipes should be bedded and backfilled in accordance with American Public Works Association(APWA)or
local jurisdictional requirements. At minimum, trench backfill should be placed and compacted as structural fill,
as described in Section 4.2 of this report. As noted,the native soils are moisture sensitive and will require careful
control of moisture to facilitate proper compaction. If utility construction takes place during the winter or if it is
not feasible to properly moisture condition the excavated soil at the time of construction, it may be necessary to
import suitable wet weather fill for utility trench backfilling.
4.9 Pavements
Pavement subgrades should be prepared as described in the Section 4.2 of this report. Regardless of the degree of
relative compaction achieved, the subgrade must be firm and relatively unyielding before paving. The subgrade
should be proofrolled with heavy rubber-tire construction equipment such as a loaded 10-yard dump truck to
verify this condition.
The pavement design section is dependent upon the supporting capability of the subgrade soils and the traffic
conditions to which it will be subjected. For traffic consisting mainly of light passenger vehicles with only
occasional heavy traffic, and with a stable subgrade prepared as recommended, we recommend the following
pavement sections:
• Two inches of hot mix asphalt concrete(HMAC)over six inches of aggregate base(AB)
• Four inches full depth HMAC over prepared subgrade
The paving materials used should conform to the current Oregon Department of Transportation (ODOT)
specifications for HMAC and AB.
Page No. 7
March 13,2015
Project No.T-7184
Long-term pavement performance will depend on surface drainage. A poorly-drained pavement section will be
subject to premature failure as a result of surface water infiltrating into the subgrade soils and reducing their
supporting capability. For optimum pavement performance, we recommend surface drainage gradients of at least
two percent. Some degree of longitudinal and transverse cracking of the pavement surface should be expected
over time. Regular maintenance should be planned to seal cracks when they occur.
5.0 ADDITIONAL SERVICES
Terra Associates, Inc. should review the final designs and specifications in order to verifythat earthwork and
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foundation recommendations have been properly interpreted and implemented in project design. We should also
provide geotechnical services during construction in order to observe compliance with our design concepts,
specifications, and recommendations. This will allow for design changes if subsurface conditions differ from
those anticipated prior to the start of construction.
6.0 LIMITATIONS
We prepared this report in accordance with generally accepted geotechnical engineering practices. This report is
the copyrighted property of Terra Associates, Inc. and is intended for specific application to the SW Hawk's
Beard Apartments project in Tigard, Oregon. This report is for the exclusive use of Holland Development and
their authorized representatives. No other warranty, expressed or implied, is made.
The analyses and recommendations presented in this report are based on data obtained from our on-site test pits.
Variations in soil conditions can occur, the nature and extent of which may not become evident until construction.
If variations appear evident, Terra Associates, Inc. should be requested to reevaluate the recommendations in this
report prior to proceeding with construction.
Page No. 8
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REFERENCE: GOOGLE MAPS 2015
ages Terra VICINITY MAP
SW HAWK'S BEARD APARTMENTS
koseasas Associates, Inc. TIGARD, OREGON -
Consultants in Geotechnical Engineering
Geology and
Environmental Earth Sciences Proj. No.T-7184 Date MAR 2015 Figure 1
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MTerra TYPICAL WALL DRAINAGE DETAIL
SW HAWK'S BEARD APARTMENTS
tissoptsis Associates, Inc. TIGARD, OREGON -
Consultants in Geotechnical Engineering
Geology Earthad Pro No. T-7184 Date MAR 2015 Figure Environmental Sciences 1• 9 3
APPENDIX A
FIELD EXPLORATION AND LABORATORY TESTING
SW Hawk's Beard Apartments
Tigard,Oregon
On March 3, 2015, we investigated subsurface conditions at the site by excavating 12 test pits to depths ranging
from about 9 to 10 feet below existing surface grades using a track-mounted excavator. The test pit locations are
shown on Figure 2. The test pit locations were approximately determined in the field by measuring and pacing
from existing surface features. The Test Pit Logs are presented on Figures A-2 through A-13.
An engineering geologist from our office maintained a log of each test pit as it was excavated, classified the soil
conditions encountered, and obtained representative soil samples. All soil samples were visually classified in the
field in accordance with the Unified Soil Classification System. A copy of this classification is presented as
Figure A-1.
Representative soil samples obtained from the test pits were placed in sealed plastic bags and taken to our
laboratory for further examination and testing. The moisture content of each sample was measured and is
reported on the Test Pit Logs. Grain size analysis was performed on one of the soil samples. The test results are
shown on Figure A-14.
Project No.T-7184
MAJOR DIVISIONS LETTER TYPICAL DESCRIPTION y
SYMBOL
Clean GW Well-graded gravels,gravel-sand mixtures, little or no fines.
GRAVELS Gravels(less
More than 50% fines) GP Poorly-graded gravels,gravel-sand mixtures,little or no fines.
J than 5%
0 m N of coarse fraction
m Ta is larger than No. GM Silty gravels,gravel-sand-silt mixtures,non-plastic fines.
w a? c 4 sieve Gravels with
Z m •N fines
1= o GC Clayey gravels,gravel-sand-clay mixtures,plastic fines.
o N
O 0 o Clean Sands SW Well-graded sands,sands with gravel,little or no fines.
toc Z SANDS (less than
Q E r More than 50% 5%fines) Sp Poorly-graded sands,sands with gravel, little or no fines.
O o " of coarse fraction
0 is smaller than SM Silty sands,sand-silt mixtures,non-plastic fines.
No. 4 sieve Sands with
fines Sc Clayey sands,sand-clay mixtures,plastic fines.
ML Inorganic silts, rock flour,clayey silts with slight plasticity.
T
J E. •N SILTS AND CLAYS
p Liquid Limit is less than 50% CL Inorganic clays of low to medium plasticity.(Lean clay)
co I; ati
CI rd *rri OL Organic silts and organic clays of low plasticity.
z E o
Rre g o MH Inorganic silts,elastic.
O c Z SILTS AND CLAYS
z co c Liquid Limit is greater than 50% CH Inorganic clays of high plasticity.(Fat clay)
rz. m -
o OH Organic clays of high plasticity.
2
HIGHLY ORGANIC SOILS PT Peat.
DEFINITION OF TERMS AND SYMBOLS
en Standard Penetration 2"OUTSIDE DIAMETER SPILT SPOON SAMPLER
w Density Resistance in Blows/Foot —
J
Z2.4"INSIDE DIAMETER RING SAMPLER OR
II
O Very Loose 0-4 SHELBY TUBE SAMPLER
Ili
Loose 4-10
= Medium Dense 10-30 y WATER LEVEL(Date)
O Dense 30-50
V Very Dense >50
Tr TORVANE READINGS,tsf
Standard Penetration Pp PENETROMETER READING,tsf
Consistancy Resistance in Blows/Foot
w DD DRY DENSITY, pounds per cubic foot
W oftt• VerySoft 0-2 4 LL LIQUID LIMIT,percent
O Medium Stiff 4-8
U Stiff 8-16 PI PLASTIC INDEX
Very Stiff 16-32
Hard >32 N STANDARD PENETRATION,blows per foot
Terra UNIFIED SOIL CLASSIFICATION SYSTEM
0101"11SW HAWK'S BEARD APARTMENTS
karma Associates Inc. TIGARD, OREGON -
Consultants in Geotechnical engineering
Geology and 1•
Environmental Earth Sciences Pro No.T-7184 Date MAR 2015 Figure A-1
LOG OF TEST PIT NO. 1 FIGURE A-2
PROJECT NAME: SW Hawk's Beard Apartments PROJ.NO: T-7184 LOGGED BY: JCS
LOCATION: Tigard.Oregon SURFACE CONDS: Flat APPROX.ELEV: N/A
DATE LOGGED: March 3.2015 DEPTH TO GROUNDWATER: 7.5 Feet DEPTH TO CAVING: N/A
U.
w
— a b
z
X J DESCRIPTION CONSISTENCY/ e a
a RELATIVE DENSITY F REMARKS
o fn 3 x
U
O
a.
(1-inch SOD and TOPSOIL)
Brown SILT to SILT with sand,moist,low plasticity to
1— nonplastic,scattered mottling,trace of fine roots. (ML)
24.2
2-
3—
Medium Dense
4-
5-
6-
36.8
7-
8— Brown SILT with sand,moist(locally wet),low plasticity to
nonplastic,scattered dark brown stained fractures,trace Medium Dense
of fine roots and root casts. (ML) to Dense
9-
10—
Test pit terminated at 10 feet.
Light temporary groundwater seepage from localized point
11— source at 7.5 feet.
12-
13-
14-
15—
Terra Associates, Inc.
NOTE: This subsurface information pertains only to this test pit location and should Consultants in Geotechnical Engineering
not be interpreted as being indicative of other locations at the site. Geology and
Environmental Earth Sciences
LOG OF TEST PIT NO. 2 FIGURE A-3
PROJECT NAME: SW Hawk's Beard Apartments PROJ.NO: T-7184 LOGGED BY: JCS
LOCATION: Tigard.Oregon SURFACE CONDS: Flat APPROX.ELEV: N/A
DATE LOGGED: March 3.2015 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: N/A
U-
N
Z
DESCRIPTION CONSISTENCY/ e a REMARKS
RELATIVE DENSITY
LLI 0 N 3 Y
(1-inch SOD and TOPSOIL)
Brown SILT to SILT with sand,moist,low plasticity to
1— nonplastic,scattered mottling,trace of fine roots. (ML)
2-
3—
Medium Dense
4-
5-
6-
7-
8-
-
5-
6-7-8— Brown SILT with sand,moist,low plasticity to nonplastic,
scattered dark brown stained fractures,trace of fine roots Medium Dense
and root casts. (ML) to Dense
9-
10—
Test pit terminated at 10 feet.
No groundwater seepage.
11-
12-
13-
14-
15—
Terra Associates, Inc.
NOTE: This subsurface information pertains only to this test pit location and should , Consultants in Geotechnical Engineering
not be interpreted as being indicative of other locations at the site. Geology and
Environmental Earth Sciences
LOG OF TEST PIT NO. 3 FIGURE A-4
PROJECT NAME: SW Hawk's Beard Apartments PROJ.NO: T-7184 LOGGED BY: JCS
LOCATION: Tigard,Oregon SURFACE CONDS: Flat APPROX.ELEV: N/A
DATE LOGGED: March 3.2015 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: N/A
LL
Cl)
2
uj
a DESCRIPTION CONRELATIVE EN DENSITY o a REMARKS
VEF
111 O m
U
O
(1-inch SOD and TOPSOIL)
Brown SILT to SILT with sand,moist,low plasticity to
1— nonplastic,scattered mottling,trace of fine roots. (ML)
2-
3—
Medium Dense
4— 33.8
5-
6-
7-
8— Brown SILT with sand,moist,low plasticity to nonplastic,
scattered dark brown stained fractures,trace of fine roots Medium Dense
and root casts. (ML) to Dense
9-
10—
Test pit terminated at 10 feet.
No groundwater seepage.
11-
12-
13-
14-
15—
i
Terra Associates, Inc.
NOTE: This subsurface information pertains only to this test pit location and should
Consultants in Geotechnical Engineering
not be interpreted as being indicative of other locations at the site. Geology and
Environmental Earth Sciences
LOG OF TEST PIT NO. 4 FIGURER-5
PROJECT NAME: SW Hawk's Beard Apartments PROJ.NO: T-7184 LOGGED BY: JCS
LOCATION: Tigard.Oregon SURFACE CONDS: Flat APPROX.ELEV: N/A
DATE LOGGED: March 3.2015 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: N/A
LL
LL w
DESCRIPTION CONSISTENCY/ oa
a g RELATIVE DENSITY r REMARKS
111 O ai �' Y
O
a
(1-inch SOD and TOPSOIL)
Brown SILT to SILT with sand,moist,low plasticity to
1— nonplastic,scattered mottling,trace of fine roots. (ML)
2-
3—
Medium Dense
4—I
5-
6
7—
8— Brown SILT with sand,moist,low plasticity to nonplastic,
scattered dark brown stained fractures,trace of fine roots Medium Dense
and root casts. (ML) to Dense
9-
10—
Test pit terminated at 10 feet.
No groundwater seepage.
11-
12-
13-
14-
15—
7,31 Terra Associates, Inc.
NOTE This subsurface information pertains only to this test pit location and should r Consultants in Geotechnical Engineeringnot be interpreted as being indicative of other locations at the site. Geology and
Environmental Earth Sciences
LOG OF TEST PIT NO. 5 FIGURE A-6
PROJECT NAME: SW Hawk's Beard Apartments PROJ.NO: T-7184 LOGGED BY: JCS
LOCATION: Tigard.Oregon SURFACE CONDS: Flat APPROX.ELEV: N/A
DATE LOGGED: March 3.2015 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: N/A
cnLL
F
z z
W CONSISTENCY/ w
aeL DESCRIPTION RELATIVE DENSITY e F REMARKS
Q
O CA
O
0-
(1-inch
(1-inch FOREST DUFF)
Brown SILT to SILT with sand,moist,low plasticity to
1— nonplastic,scattered mottling,trace of fine roots. (ML)
2— 27.3
3—
Medium Dense
4-
5—
6
7—
Brown SILT with sand,moist(locally wet),low plasticity to
8— nonplastic,scattered dark brown stained fractures,trace
of fine roots and root casts. (ML) Medium Dense
to Dense
9-
10—
Test pit terminated at 10 feet.
No groundwater seepage.
11-
12-
13-
14-
15—
Terra Associates, Inc.
NOTE: This subsurface information pertains only to this test pit location and should >. Consultants in Geotechnical Engineering
not be interpreted as being indicative of other locations at the site. m Geology and
Environmental Earth Sciences
LOG OF TEST PIT NO. 6 FIGURE A-7
PROJECT NAME: SW Hawk's Beard Apartments PROJ.NO: T-7184 LOGGED BY: JCS
LOCATION: Tigard. Oregon SURFACE CONDS: Flat APPROX.ELEV: N/A
DATE LOGGED: March 3.2015 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: N/A
LL
- d F
LL zuj
X a DESCRIPTION CONSISTENCY/ e a REMARKS
111
RELATIVE DENSITY Y
U
0
a.
(1-inch SOD and TOPSOIL)
Brown SILT to SILT with sand,moist,low plasticity to
1— nonplastic,scattered mottling,trace of fine roots. (ML)
2-
3—
Medium Dense
4-
5-
6-
8—
7—'
Brown SILT with sand,moist,low plasticity to nonplastic,
scattered dark brown stained fractures,trace of fine roots Medium Dense
and root casts. (ML) to Dense
9-
10-
Test pit terminated at 10 feet.
No groundwater seepage.
11—
12—
13—
14—
15—
,. Terra Associates, Inc.
NOTE: This subsurface information pertains only to this test pit location and should mir,F7t3 Consultants in Geotechnical Engineering
not be interpreted as being indicative of other locations at the site. "" ` Geology and
Environmental Earth Sciences
LOG OF TEST PIT NO. 7 FIGURE A-8
PROJECT NAME: SW Hawk's Beard Apartments PROJ.NO: T-7184 LOGGED BY: JCS
LOCATION: Tgard.Oregon SURFACE CONDS: Flat APPROX.ELEV: N/A
DATE LOGGED: March 3.2015 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: N/A
U-
—
d)
O
z
F d DESCRIPTION CONSISTENCY/ o a REMARKS
a 0- RELATIVE DENSITY
O vdi 3 Y
U
0
a
(1-inch SOD and TOPSOIL)
Brown SILT to SILT with sand,moist,low plasticity to
1— nonplastic,scattered mottling,trace of fine roots. (ML)
2-
3—
Medium Dense
4-
5-
6— 35.2
7—
Brown SILT with sand,moist,low plasticity to nonplastic,
8— scattered dark brown stained fractures,trace of fine roots Medium Dense
and root casts. (ML) to Dense
9-
10— Test pit terminated at 9.5 feet.
No groundwater seepage.
11-
12-
13-
14-
15—
Terra Associates, Inc.
NOTE: This subsurface information pertains only to this test pit location and should Consultants in Geotechnical Engineering
not be interpreted as being indicative of other locations at the site. Geology and
Environmental Earth Sciences
L
LOG OF TEST PIT NO. 8 FIGURE A-9
PROJECT NAME: SW Hawk's Beard Apartments PROJ.NO: T-7184 LOGGED BY: JCS
LOCATION: Tigard.Oregon SURFACE CONDS: Flat APPROX.ELEV: N/A
DATE LOGGED: March 3.2015 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: N/A
LL
Z ~
w DESCRIPTION CONSISTENCY/ a
a RELATIVE DENSITY t REMARKS
LU pal 3 Y
U
O
(1-inch SOD and TOPSOIL)
Brown SILT to SILT with sand,moist,low plasticity to
1— nonplastic,scattered mottling,trace of fine roots. (ML)
2-
3—
Medium Dense
4-
5-
6-
7—
Brown SILT with sand,moist,low plasticity to nonplastic,
scattered dark brown stained fractures,trace of fine roots Medium Dense
8— and root casts. (ML)
to Dense
9—
Test pit terminated at 9 feet.
No groundwater seepage.
10-
11-
12-
13-
14-
15—
,,47Terra Associates, Inc.
NOTE: This subsurface information pertains only to this test pit location and should Consultants in Geotechnical Engineering
not be interpreted as being indicative of other locations at the site. Geology and -
Environmental Earth Sciences
1
LOG OF TEST PIT NO. 9 FIGURE A-10
PROJECT NAME: SW Hawk's Beard Apartments PROJ.NO: T-7184 LOGGED BY: JCS
LOCATION: Tigard. Oregon SURFACE CONDS: Flat APPROX.ELEV: N/A
DATE LOGGED: March 3.2015 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: N/A
LL
N
- z v
w
_ DESCRIPTION CONSISTENCY! a a
Z.-
o. g RELATIVE DENSITY REMARKS
3 Ili
0 41O
0-
(1-inch
(1-inch SOD and TOPSOIL)
Brown SILT to SILT with sand,moist,low plasticity to
nonplastic,scattered mottling,trace of fine roots. (ML)
1-
2-
3—
Medium Dense
4—
6-
7-
8— Brown SILT with sand,moist,low plasticity to nonplastic, Medium Dense
scattered dark brown stained fractures,trace of fine roots
and root casts. (ML) to Dense
9—
Test pit terminated at 9.5 feet.
10— No groundwater seepage.
11—
Terra Associates, Inc.
NOTE: This subsurface information pertains only to this test pit location and should ? # Consultants in Geotechnical Engineering
"
not be interpreted as being indicative of other locations at the site. `" Geology and
Environmental Earth Sciences
LOG OF TEST PIT NO. 10 FIGURE A-11
PROJECT NAME: SW Hawk's Beard Apartments PROJ.NO: T-7184 LOGGED BY: JCS
LOCATION: Tigard.Oregon SURFACE CONDS: Flat APPROX.ELEV: N/A
DATE LOGGED: March 3.2015 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: N/A
LL
N
LL z
uj
CONSISTENCY/ w
e DESCRIPTION RELATIVE DENSITY F REMARKS
O y
O
(1-inch SOD and TOPSOIL)
Brown SILT to SILT with sand,moist,low plasticity to
1— nonplastic,scattered mottling,trace of fine roots. (ML)
2-
3—
Medium Dense
4-
5-
6-
7—
Brown SILT with sand,moist,low plasticity to nonplastic,
8— scattered dark brown stained fractures,trace of fine roots Medium Dense
and root casts. (ML) to Dense
9-
34.6
10— Test pit terminated at 9.5 feet.
No groundwater seepage.
11-
12-
13-
14-
15—
Terra Associates, Inc.
NOTE This subsurface information pertains only to this test pit location and should ? f:: Consultants in Geotechnical Engineering
not be interpreted as being indicative of other locations at the site. Geology and
Environmental Earth Sciences
LOG OF TEST PIT NO. 11 FIGURER-12
PROJECT NAME: SW Hawk's Beard Apartments PROJ.NO: T-7184 LOGGED BY: JCS
LOCATION: Tigard. Oregon SURFACE CONDS: Flat APPROX.ELEV: N/A
DATE LOGGED: March 3,2015 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: N/A
LL
H Z `~'
CONSISTENCY/ ea DESCRIPTION
REMARKSF RELATIVE DENSITY a 0-CI CO
O
o.
(1-inch SOD and TOPSOIL)
Brown SILT to SILT with sand,moist,low plasticity to
1— nonplastic,scattered mottling,trace of fine roots. (ML)
2-
3-
31.7
Medium Dense
4-
5-
6-
7—
Brown SILT with sand,moist,low plasticity to nonplastic,
8— scattered dark brown stained fractures,trace of fine roots Medium Dense
and root casts. (ML) to Dense
9-
10— Test pit terminated at 9.5 feet.
No groundwater seepage.
11-
12-
13-
14-
15—
Terra Associates, Inc.
NOTE This subsurface information pertains only to this test pit location and should +" <F" Consultants in Geotechnical Engineering
not be interpreted as being indicative of other locations at the site. Geology and
Environmental Earth Sciences
LOG OF TEST PIT NO. 12 FIGURE A-13
PROJECT NAME: SW Hawk's Beard Apartments PROJ.NO: T-7184 LOGGED BY: JCS
LOCATION: Tigard.Oregon SURFACE CONDS: Flat APPROX.ELEV: N/A
DATE LOGGED: March 3.2015 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: N/A
LL
F
Z
LL Z
a DESCRIPTION CONSISTENCY/ o i REMARKS
RELATIVE DENSITY r
w < 3 w
O V) 0
v
0
a.
(1-inch SOD and TOPSOIL)
Brown SILT to SILT with sand,moist,low plasticity to
1— nonplastic,scattered mottling,trace of fine roots. (ML)
2-
3—
Medium Dense
4-
5-
6-
7—
Brown SILT with sand,moist,low plasticity to nonplastic,
8— scattered dark brown stained fractures,trace of fine roots Medium Dense
and root casts. (ML) to Dense
9-
10— Test pit terminated at 9.5 feet.
No groundwater seepage.
11-
12-
13-
14-
15—
Terra Associates, Inc.
NOTE: This subsurface information pertains only to this test pit location and should Consultants in Geotechnical Engineering
not be interpreted as being indicative of other locations at the site. Geology and
Environmental Earth Sciences
Particle Size Distribution Report
G C C C C OO O O O N (0 _O _Q
f0 0 N e- \ C7 # # i A # #
100
M
80
70
W 60
Z 50
CL
40
30
20
10
0 I I I I I I I L
100 10 1 0.1 0.01 0.001
GRAIN SIZE-mm.
"/,+3" %Gravel %Sand _ %Fines
Coarse Fine Coarse Medium Fine Silt Clay
o 0.0 0.0 0.0 0.2 6.5 11.4 81.9
X LL PL D85 D60 D50 D30 D15 D10 Cc Cu
o 0.1059
Material Description USCS AASHTO
o SILT with sand ML
Project No. T-7184 Client: Holland Development Remarks:
Project: SW Hawk's Beard Apartments o Tested 3-4-15
o Location:TP-5 Depth:2'
Terra Associates, Inc.
Kirkland, WA Figure A-14
Tested By: FQ