Report (104) OFFICE COPY
° ie ) RECEIVED
kr1-1-\ ewt. AUG 2 1 2018
CITY OF TIGARD
BUILDING DIVISION
MIN
GeopEngineering, Inc.
Real-World Geotechnical Solutions
Investigation • Design • Construction Support
Geotechnical Engineering Report
72nd Avenue Apartments
11720 & 11750 SW 72nd Avenue
Tigard, Oregon 97223
GeoPacific Engineering, Inc. Job No. 17-4626
Revised August 20, 2018
14835 SW 72nd Avenue Tel (503) 598-8445
Portland, Oregon 97224 Fax (503) 941-9281
GeoPacific
Engineering,Ine.
Real-World Geotechnical Solutions
Investigation • Design • Construction Support
TABLE OF CONTENTS
List of Appendices
List of Figures
PROJECT INFORMATION 1
SITE AND PROJECT DESCRIPTION 2
REGIONAL GEOLOGIC SETTING 2
REGIONAL SEISMIC SETTING 3
Portland Hills Fault Zone 3
Lacamas Creek/Sandy River Fault Zone 3
Gales Creek-Newberg-Mt. Angel Structural Zone 4
Cascadia Subduction Zone 4
FIELD EXPLORATION AND SUBSURFACE CONDITIONS 5
Soil Descriptions 6
Groundwater and Soil Moisture 7
Infiltration Testing 7
CONCLUSIONS AND RECOMMENDATIONS 8
Site Preparation Recommendations 9
Engineered Fill 9
Excavating Conditions and Utility Trench Backfill 10
Erosion Control Considerations 11
Wet Weather Earthwork 11
Spread Foundations 12
Concrete Slabs-on-Grade 13
Footing and Roof Drains 14
Permanent Below-Grade Walls 14
PAVEMENT EVALUATION AND DESIGN 16
SW 72nd Avenue— East Lane: Existing Pavement Evaluation 16
SW 72nd Avenue: New Pavement Design For Street Widening 19
Flexible Pavement Design —Private Parking Areas 20
Rigid Pavement Design— Private Parking and Drive Areas 21
Subgrade Preparation 22
Wet Weather Construction Pavement Section 22
Stormwater Management 16
SEISMIC DESIGN 23
Soil Liquefaction 24
UNCERTAINTIES AND LIMITATIONS 26
REFERENCES 27
CHECKLIST OF RECOMMENDED GEOTECHNICAL TESTING AND OBSERVATION 28
APPENDIX
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Geo Pacific
Englneerfng.inc
Real-World Geotechnical Solutions
Investigation • Design • Construction Support
List of Appendices
Figures
Exploration Logs
Laboratory Test Results
Liquefaction Assessment
Infiltration Testing Calculations
Pavement Design Calculations
Site Research
Photographic Log
List of Figures
1 Site Vicinity Map
2 Site Aerial and Exploration Locations
3 Site Plan and Exploration Locations
4 Site Plan and Foundation Loads
5 Typical Perimeter Footing Drain Detail
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\rem- -
GeoPacitic
Real-World Geotechnical Solutions
Investigation • Design • Construction Support
Revised August 20, 2018
Project No. 17-4626
72nd Avenue Property, LLC
do Hill Architects
1750 Blankenship Road, Suite 400
West Linn, Oregon 97068
Phone: (503) 305-8033
SUBJECT: GEOTECHNICAL ENGINEERING REPORT
72"D AVENUE APARTMENTS
11720 & 11750 SW 72ND AVENUE
TIGARD, OREGON 97223
PROJECT INFORMATION
This report presents the results of a geotechnical engineering study conducted by GeoPacific
Engineering, Inc. (GeoPacific) for the above-referenced project. The purpose of our investigation
was to evaluate subsurface conditions at the site, and to provide geotechnical recommendations
for site development. This geotechnical study was performed in accordance with GeoPacific
Proposal No. P-6092, dated May 24, 2017, and your subsequent authorization of our proposal and
General Conditions for Geotechnical Services.
11720 & 11750 SW 72nd Avenue
Site Location: Tigard, Oregon 97223
Washington County Parcel No. R285587 & R285596
Hill Architects
Architect: 1750 Blankenship Road, Suite 400
West Linn, Oregon 97068
Phone: (503}305-8033
Jurisdictional Agency: City of Tigard, Oregon
GeoPacific Engineering, Inc
14835 SW 72nd Avenue
Prepared By: Portland, Oregon 97224
Tel (503) 598-8445 Fax (503) 941-9281
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Project No. 17-4626, 72"d Avenue Apartments, Tigard, Oregon Enaneertui
SITE AND PROJECT DESCRIPTION
As indicated on Figures 1 through 3, the subject site is located at 11720, and 11750 SW 72nd
Avenue, in Tigard, Oregon. The site is comprised of Washington County Parcel No. R285587, and
R28596, totaling approximately 0.67-acres in size, and is roughly rectangular in shape. The site
latitude and longitude is 45.435202, -122.750626, and the legal description is the SW 1/4 of Section
36, T1S, R1W, Willamette Meridian. The regulatory jurisdictional agency is the City of Tigard,
Oregon. The site is bordered by SW 72nd Avenue to the west, and by existing residential
properties to the north, east, and south. The properties contain two existing residential homes,
driveways, and ornamental lawn areas which include landscaping retaining walls, gardens, and
planter areas. The property owner has indicated to GeoPacific that an extensive dewatering
system was installed across the site which includes drains, culverts, and gravel. The drive areas in
the front of the house are surfaced with asphalt and gravel. Topography at the site is generally
relatively flat to gently sloping to the west with site elevations ranging from approximately 234 to
244 feet above mean sea level (amsl). Vegetation at the site primarily consists of grass,
landscaping plants, and some trees.
Based upon communication with the client, and review of preliminary project plans, GeoPacific
understands that the proposed development at the site will consist of construction of a five-story,
mixed-use building, with retail and parking spaces on the ground level, and multi-family residential
units on the upper levels. The building will have a footprint of approximately 9,906 square-feet,
and will be located on the western portion of the site (see Figure 3). We understand that the
development will also include construction of private parking areas and drive areas, a trash
enclosure, and a public street improvement to the eastern margin of SW 72nd Avenue along the
property frontage. Associated underground utilities, and stormwater disposal systems will also be
installed. We anticipate that site grading will include cuts and fills which will be on the order of five
feet or less.
Based upon review of information provided by Hill Architects, it is our understanding that the
proposed building will be designed as Type V construction, with slab-on-grade, post and pier, or
spread footing foundations on the ground level, a post-tensioned concrete slab at the second level,
and wood framing above. Based upon structural loading information provided by DCI Engineers
(see Figure 4), we anticipate maximum structural loading on column footings and continuous strip
footings on the order of 100 to 225 kips, and 4 to 10 kips respectively.
REGIONAL GEOLOGIC SETTING
Regionally, the subject site lies within the Willamette Valley/Puget Sound lowland, a broad
structural depression situated between the Coast Range on the west and the Cascade Range on
the east. A series of discontinuous faults subdivide the Willamette Valley into a mosaic of
fault-bounded, structural blocks (Yeats et al., 1996). Uplifted structural blocks form bedrock
highlands, while down-warped structural blocks form sedimentary basins.
According to the Lidar-Based Surficial Geologic Map of the Greater Portland Area, Clackamas,
Columbia, Marion, Multnomah, Washington, and Yamhill Counties, Oregon, and Clark County,
Washington, 2012 (State of Oregon Department of Geology and Mineral Industries Open-File
Report 0-12-02), the site is underlain by late Pleistocene-aged (21,000 to 12,000 years ago) fine-
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grained Missoula Flood Deposits (Mff). The fine-grained sediments were deposited by outburst
flooding of glacial Lake Missoula, a catastrophic flood deposit associated with repeated glacial
outburst flooding of the Willamette Valley (Yeats et al., 1996), and consist of white, tan, and brown,
unconsolidated, sand and silt that were deposited in a series of distinct layers, a few inches to a
few feet thick, each of which represent an individual flooding event.
REGIONAL SEISMIC SETTING
At least four major fault zones capable of generating damaging earthquakes are thought to exist in
the vicinity of the subject site. These include the Portland Hills Fault Zone, the Lacamas
Creek/Sandy River Fault Zone, the Gales Creek-Newberg-Mt. Angel Structural Zone, and the
Cascadia Subduction Zone.
Portland Hills Fault Zone
The Portland Hills Fault Zone is a series of NW-trending faults that include the central Portland
Hills Fault, the western Oatfield Fault, and the eastern East Bank Fault. These faults occur in a
northwest-trending zone that varies in width between 3.5 and 5.0 miles. The combined three faults
reportedly vertically displace the Columbia River Basalt by 1,130 feet and appear to control
thickness changes in late Pleistocene (approx. 780,000 years) sediment (Madin, 1990). The
Portland Hills Fault occurs along the Willamette River at the base of the Portland Hills, and is
located approximately 5.6 miles northeast of the site. The Oatfield Fault occurs along the western
side of the Portland Hills, and is located approximately 3.5 miles northeast of the site. The East
Bank Fault occurs along the eastern margin of the Willamette River, and is located approximately 8
miles northeast of the site. The accuracy of the fault mapping is stated to be within 500 meters
(Wong, et al., 2000).
According to the USGS Earthquake Hazards Program, the fault was originally mapped as a down-
to-the-northeast normal fault, but has also been mapped as part of a regional-scale zone of right-
lateral, oblique slip faults, and as a steep escarpment caused by asymmetrical folding above a
south-west dipping, blind thrust fault. The Portland Hills fault offsets Miocene Columbia River
Basalts, and Miocene to Pliocene sedimentary rocks of the Troutdale Formation. No fault scarps
on surficial Quaternary deposits have been described along the fault trace, and the fault is mapped
as buried by the Pleistocene aged Missoula flood deposits. No historical seismicity is correlated
with the mapped portion of the Portland Hills Fault Zone, but in 1991 a M3.5 earthquake occurred
on a NW-trending shear plane located 1.3 miles east of the fault (Yelin, 1992). Although there is
no definitive evidence of recent activity, the Portland Hills Fault Zone is assumed to be potentially
active (Geomatrix Consultants, 1995).
Lacamas Creek/ Sandy River Fault Zone
The Lacamas Creek Fault intersects the northeast trending Sandy River Fault north of Camas,
Washington at Lacamas Lake, approximately 20 miles northeast of the subject site. The Lacamas
Creek Fault extends northwest to southeast, intersecting the northeast, southwest trending Sandy
River Fault. According to the USGS Earthquake Hazards Program the fault has been mapped as a
normal fault with down-to-the-southwest displacement, and has also been described as a steeply
northeast or southwest-dipping, oblique, right-lateral, slip-fault. The trace of the Lacamas Lake
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fault is marked by the very linear lower reach of Lacamas Creek. No fault scarps on Quaternary
surficial deposits have been described. The Lacamas Lake fault offsets Pliocene-aged
sedimentary conglomerates generally identified as the Troutdale formation, and Pliocene to
Pleistocene aged basalts generally identified as the Boring Lava formation. Recent seismic
reflection data across the probable trace of the fault under the Columbia River yielded no
unequivocal evidence of displacement underlying the Missoula flood deposits, however, recorded
mild seismic activity during the recent past indicates this area may be potentially seismogenic.
Gales Creek-Newberg-Mt. Angel Structural Zone
The Gales Creek-Newberg-Mt. Angel Structural Zone is a 50-mile-long zone of discontinuous,
NW-trending faults that lies about 14.3 miles southwest of the subject site. These faults are
recognized in the subsurface by vertical separation of the Columbia River Basalt and offset seismic
reflectors in the overlying basin sediment (Yeats et al., 1996; Werner et al., 1992). A geologic
reconnaissance and photogeologic analysis study conducted for the Scoggins Dam site in the
Tualatin Basin revealed no evidence of deformed geomorphic surfaces along the structural zone
(Unruh et al., 1994). No seismicity has been recorded on the Gales Creek Fault or Newberg Fault
(the fault closest to the subject site); however, these faults are considered to be potentially active
because they may connect with the seismically active Mount Angel Fault and the rupture plane of
the 1993 M5.6 Scotts Mills earthquake (Werner et al. 1992; Geomatrix Consultants, 1995).
According to the USGS Earthquake Hazards Program, the Mount Angel fault is mapped as a high-
angle, reverse-oblique fault, which offsets Miocene rocks of the Columbia River Basalts, and
Miocene and Pliocene sedimentary rocks. The fault appears to have controlled emplacement of
the Frenchman Spring Member of the Wanapum Basalts, and thus must have a history that
predates the Miocene age of these rocks. No unequivocal evidence of deformation of Quaternary
deposits has been described, but a thick sequence of sediments deposited by the Missoula floods
covers much of the southern part of the fault trace.
Cascadia Subduction Zone
The Cascadia Subduction Zone is a 680-mile-long zone of active tectonic convergence where
oceanic crust of the Juan de Fuca Plate is subducting beneath the North American continent at a
rate of 4 cm per year (Goldfinger et al., 1996). A growing body of geologic evidence suggests that
prehistoric subduction zone earthquakes have occurred (Atwater, 1992; Carver, 1992; Peterson et
al., 1993; Geomatrix Consultants, 1995). This evidence includes: (1) buried tidal marshes
recording episodic, sudden subsidence along the coast of northern California, Oregon, and
Washington, (2) burial of subsided tidal marshes by tsunami wave deposits, (3) paleoliquefaction
features, and (4) geodetic uplift patterns on the Oregon coast. Radiocarbon dates on buried tidal
marshes indicate a recurrence interval for major subduction zone earthquakes of 250 to 650 years
with the last event occurring 300 years ago (Atwater, 1992; Carver, 1992; Peterson et al., 1993;
Geomatrix Consultants, 1995). The inferred seismogenic portion of the plate interface lies
approximately along the Oregon Coast at depths of between 20 and 40 kilometers below the
surface.
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FIELD EXPLORATION AND SUBSURFACE CONDITIONS
Our subsurface explorations for this report were conducted on July 3, 2017 and July 31, 2017. On
July 3, 2017, a total of three exploratory soil borings (B-1 through B-3) were drilled at the site using
a trailer-mounted, solid-stem auger drill rig subcontracted by GeoPacific to a depth of
approximately 41.5 feet bgs. At each boring location, SPT (Standard Penetration Test) sampling
was performed in general accordance with ASTM D1586 using a 2-inch outside diameter split-
spoon sampler and a 140-pound hammer equipped with an auto-hammer mechanism. During the
test, a sample is obtained by driving the sampler 18 inches into the soil at the target test depth with
the hammer free-falling from a height of 30 inches. The number of blows for each 6 inches of
penetration is recorded. The Standard Penetration Resistance ("N-Value") of the soil is calculated
as the number of blows required for the final 12 inches of penetration. If 50 or more blows are
recorded within a single 6-inch interval, the test is terminated, and the blow count is recorded as 50
blows for the number of inches driven. This resistance, or N-Value, provides a measure of the
relative density of granular soils and the relative consistency of cohesive soils.
On July 31, 2017, one electronic cone penetrometer test (CPT) exploration, designated CPT-1,
was advanced on the subject property to a depth of 53.2 feet. The CPT sounding was advanced
by Oregon Explorations with a track-mounted cone penetrometer. Continuous tip resistance
measurements were recorded and correlated with equivalent Standard Penetration Test (SPT)
N-values. Pore water pressure values were also measured. Logs of the CPT soundings, including
interpreted soil behavior types and equivalent SPT N-values, are attached.
GeoPacific conducted infiltration testing within some of the boreholes at various depths to
determine if infiltration of stormwater is geotechnically feasible at the subject site. Infiltration test
procedures, test locations, and infiltration results are presented below.
GeoPacific conducted an evaluation of the existing pavement sections in the eastern lane of SW
72nd Avenue along the property frontage. The pavement evaluation included drilling three core
holes (RC-1 through RC-3), through the existing pavement sections at the approximate locations
indicated on Figure 2. The results of the existing pavement evaluation of SW 72nd Avenue are
presented below.
Explorations were conducted under the full-time observation of GeoPacific personnel. During the
explorations, GeoPacific observed and recorded pertinent soil information such as color,
stratigraphy, strength, and soil moisture content. Soil samples obtained from the explorations were
placed in relatively air-tight plastic bags. Pertinent information including soil sample depths,
stratigraphy, soil engineering characteristics, and groundwater occurrence was recorded. Soils
were classified in accordance with the Unified Soil Classification System (USCS). At the
completion of each test, the soil borings and the CPT exploration were backfilled with bentonite
chips. The pavement cores were re-patched with concrete.
The approximate locations of the explorations are indicated on Figures 2 and 3. It should be noted
that exploration locations were located in the field by pacing or taping distances from apparent
property corners and other site features shown on the plans provided. As such, the locations of
the explorations should be considered approximate. Summary exploration logs are attached. The
stratigraphic contacts shown on the individual subsurface logs represent the approximate
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boundaries between soil types. The actual transitions may be more gradual. The soil and
groundwater conditions depicted are only for the specific dates and locations reported, and
therefore, are not necessarily representative of other locations and times. Soil and groundwater
conditions encountered in the explorations are summarized below.
Soil and groundwater conditions encountered in the explorations are summarized below.
Soil Descriptions
Topsoil: At the locations of soil boring explorations B-1, and B-3, the ground was surfaced with
lawn grass, with an underlying organic horizon consisting of organic Lean CLAY (OL-CL),
extending to a depth of approximately 10 inches bgs.
Asphalt Parking: At the location soil boring B-2, the ground was surfaced with an asphalt
driveway. The pavement section was observed to consist of approximately 3 inches of asphalt,
underlain by approximately 6 inches of crushed aggregate base.
Lean CLAY: Underlying the topsoil and pavement sections at the locations of our soil borings,
soils were observed to consist primarily of brown and dark gray, containing sparse angular gravel
and trace charred organic material, medium stiff, moist, moderately plastic, Lean CLAY (CL). The
soil type extended to an approximate depth of 10 feet bgs within our soil borings. Laboratory soils
testing indicated that the soil type classified as Lean CLAY (CL) according to the USCS soil
classification system, and as A-7-6(24) according to AASHTO standards. Sieve analysis indicated
92.3 percent by weight passing the U.S. No. 200 sieve, and moisture content of 28.2 percent.
Atterberg Limit testing indicated a liquid limit of 46, and a plasticity index of 23. SPT blow counts
indicated N-values ranging from 6 to 12 within the soil layer.
SILT: Underlying the Lean CLAY soil type at the locations of our soil borings, soils were observed
to consist primarily of brown, medium stiff, very moist to wet, low plasticity, SILT (ML). The soil
type extended to approximate depths of 20 to 30 feet bgs within our soil borings. Laboratory soils
testing indicated that the soil type classified as SILT (ML) according to the USCS soil classification
system, and as A-4(0), A-4(2), A-4(7), and A-4(9) according to AASHTO standards. Sieve analysis
indicated 85.3 to 94.8 percent by weight passing the U.S. No. 200 sieve, and moisture content of
32.5 to 39.5 percent. Atterberg Limit testing indicated a liquid limit of 26 to 34, and a plasticity
index of 0 to 8. SPT blow counts indicated N-values ranging from 2 to 11 within the soil layer.
Cone tip resistances in the low-plasticity silt layer generally ranged from 10 to 20 tons per square
foot, with sleeve friction values of 0.2 to 0.8 tons per square foot.
Elastic SILT: Underlying the low plasticity silt soil type at the locations of our soil borings, soils
were observed to consist primarily of light brown to blue gray, stiff to very stiff, wet, micaceous,
highly plastic, elastic SILT (MH). The elastic silt soil type extended to approximate depths of 37 to
38 feet bgs within our soil borings. Laboratory soils testing indicated that the soil type classified as
Elastic SILT (MH) according to the USCS soil classification system, and as A-7-5(34) according to
AASHTO standards. Sieve analysis indicated 94.6 percent by weight passing the U.S. No. 200
sieve, and moisture content of 41.6 percent. Atterberg Limit testing indicated a liquid limit of 61,
and a plasticity index of 28. SPT blow counts indicated N-values ranging from 7 to 27 within the
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soil layer. Cone tip resistances in the elastic silt layer generally ranged from 40 to 95 tons per
square foot, with sleeve friction values of 0.9 to 1.5 tons per square foot.
Fat CLAY: Underlying the Elastic SILT soil type at the locations of soil borings B-1 and B-3, soils
were observed to consist primarily of blue gray, stiff to very stiff, wet, highly plastic, Fat CLAY (CH).
The soil type extended to the maximum depth of exploration within our soil borings. Practical
refusal was encountered in the CPT exploration CPT-1 at a depth of 53.2 feet.Laboratory soils
testing indicated that the fat clay layer classified as Fat CLAY (CH) according to the USCS soil
classification system, and as A-7-5(64) according to AASHTO standards. Sieve analysis indicated
89.0 percent by weight passing the U.S. No. 200 sieve, and moisture content of 41.2 percent.
Atterberg Limit testing indicated a liquid limit of 94, and a plasticity index of 62. SPT blow counts
indicated N-values ranging from 11 to 25 within the soil layer. Cone tip resistances in the fat clay
layer generally ranged from 40 to 95 tons per square foot, with sleeve friction values of 0.9 to 2.2
tons per square foot.
Groundwater and Soil Moisture
On July 3, 2017, observed soil moisture conditions were generally moist to wet. Groundwater
seepage was observed at depths ranging from approximately 12.5 to 15 feet bgs within our soil
borings which extended to a maximum depth of 41.5 feet bgs. On July 31, 2018, we observed
groundwater at a depth of 12.5 feet in CPT-1.
According to the Estimated Depth to Groundwater in the Portland, Oregon Area, (United States
Geological Survey, Snyder, 2017 website), groundwater may be encountered at an approximate
depth ranging from 10 to 20 feet below the ground surface. It is anticipated that groundwater
conditions will vary depending on the season, local subsurface conditions, changes in site
utilization, and other factors. Perched groundwater may be encountered in localized areas. Seeps
and springs may exist in areas not explored, and may become evident during site grading. If the
seasonal fluctuation of the static groundwater table underlying the subject site require detailed
understanding, piezometers may be installed and periodically monitored.
Infiltration Testing
Soil infiltration testing was performed using the open-borehole method within soil borings B-1, and
B-2 in accordance with the methodology of the 2016 City of Portland Stormwater Management
Manual. The approximate locations of the subsurface explorations are indicated on Figures 2 and
3. The test locations were pre-saturated prior to testing. During testing the water level was
measured to the nearest 0.01 foot (1/8 inch) from a fixed point, and the change in water level was
recorded at regular intervals until three successive measurements showing a consistent infiltration
rate were achieved.
Table 1 summarizes the test locations and results of the infiltration testing. Infiltration rates have
been reported without applying a factor of safety. Soils at the test locations were observed and
sampled in order to characterize the subsurface profile. Tested native soils classified as Lean
CLAY, and SILT. Groundwater was encountered within our soil boring explorations at depths
ranging from 12.5 to 15 feet bgs. Infiltration testing data tables are presented in the appendix of
this report.
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Table 1 -Summary of Infiltration Test Results
Percent Infiltration Hydraulic Depth to
Test Exploration Depth Soil Passing U.S. Rate Head Range Groundwater
Location Designation (feet) Type No. 200 (inches/hr) (inches) (Feet)
Sieve
B-1 IT-1.1 10 CL 85.3 0 12 15
B-1 IT-1.2 20 ML 94.8 0 12 15
B-2 IT-2.1 5 CL - 0 12 12.5
B-2 IT-2.2 10 ML - 0 12 12.5
B-2 IT-2.3 20 ML - 0 12 12.5
The results of our subsurface exploration and testing indicate that due to the lack of measured
infiltration at the test locations, the presence of fine-grained soils, and the shallow depths to static
groundwater, infiltration of stormwater is not geotechnically feasible at the subject site.
CONCLUSIONS AND RECOMMENDATIONS
Our site investigation indicates that the proposed construction is geotechnically feasible, provided
that the recommendations of this report are incorporated into the design and construction phases
of the project. The primary geotechnical concerns associated with development at the subject site
are:
• The presence of liquefiable soil conditions underlying the subject site which have the
potential for up to 8 inches of post-liquefaction settlement, and 7 feet of lateral spreading
during a large Cascadia Subduction Zone earthquake;
• The potential for up to 3 inches of static settlement to occur under the building loading;
• The lack of infiltration at the subject site; and
• The presence of groundwater at relatively shallow depths.
We recommend the installation of engineered aggregate piers as ground improvement for the site
for the purpose of lowering the risk of damage to the structure from post-liquefaction settlement,
lateral spreading, and static settlement. Engineered aggregate piers (EAPs), commonly referred to
as geopiers, involve compacting crushed rock into the soil using displacement methods or
predrilled holes. Due to the presence of shallow groundwater and potentially caving soils, EAPs
installed on this site should be installed with displacement methods. The crushed rock is typically
placed in lifts 12 to 18 inches thick and is compacted with a hammer. This method densifies the
surrounding soils.
Engineered aggregate piers should be installed in a grid pattern with adequate depth and spacing.
Engineered aggregate pier depth of 25 feet will generally be adequate, except for in the vicinity of
boring B-1 and CPT-1. In the vicinity of boring B-1 and CPT-1, we recommend a pier depth of at
least 30 feet.
Engineered aggregate piers are typically designed and installed by a design-build contractor. The
design-build contractor would use the subsurface information provided in this geotechnical
engineering report. GeoPacific has reviewed design documents from the design-build contractor. It
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is our opinion that engineered aggregate piers are an acceptable method of ground improvement
for the site.
Based on the soils encountered in our explorations, the presence of groundwater at depths of 12.5
to 15 feet bgs, and the results of our infiltration testing, it is our opinion that subsurface disposal of
stormwater through infiltration is not feasible.
Site Preparation Recommendations
The subject site is currently occupied by two existing homes which include driveways, and
landscaping areas. It is unclear whether or not the homes contain basements. Areas of proposed
construction and areas to receive fill should be cleared of landscaping, existing retaining walls,
vegetation, and any organic and inorganic debris, and unsuitable soils. The current property owner
indicated that an extensive dewatering system was installed across the site which includes drains,
culverts, and gravel. Inorganic debris and organic materials from clearing should be removed from
the site. Organic-rich soils and root zones should then be stripped from construction areas of the
site or where engineered fill is to be placed. Depth of stripping of organic soils is estimated to be
approximately 8 to 24 inches across the majority of the site, however depth of organic soil layers
may increase in areas where trees are present, or where existing utilities such as culverts have
been installed. If encountered, basement debris should be thoroughly removed and the
excavations backfilled with approved engineered fill. The final depth of soil removal will be
determined on the basis of a site inspection after the stripping/excavation has been performed.
Stripped topsoil should be removed from the site. Any remaining topsoil should be stockpiled only
in designated areas and stripping operations should be observed and documented by the
geotechnical engineer or his representative. Prior to placement of engineered fill, subgrade soils
should be aerated and re-compacted to minimum depth of 12 inches below the existing topsoil
layer.
If encountered, undocumented fills and any subsurface structures (dry wells, basements, driveway
and landscaping fill, old utility lines, septic leach fields, etc.) should be completely removed and the
excavations backfilled with approved engineered fill.
Engineered Fill
All grading for the proposed construction should be performed as engineered grading in
accordance with the applicable building code at the time of construction with the exceptions and
additions noted herein. Areas proposed for fill placement should be prepared as described in the
Site Preparation Recommendations section. Surface soils should then be scarified and
recompacted prior to placement of structural fill. Proper test frequency and earthwork
documentation usually requires daily observation and testing during stripping, rough grading, and
placement of engineered fill.
Onsite native soils consisting of Lean CLAY and SILT, appear to be suitable for use as engineered
fill. Soils containing greater than 5 percent organic content should not be used as structural fill.
Imported fill material must be approved by the geotechnical engineer prior to being imported to the
site. Oversize material greater than 6 inches in size should not be used within 3 feet of foundation
footings, and material greater than 12 inches in diameter should not be used in engineered fill.
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Engineered fill should be compacted in horizontal lifts not exceeding 8 inches using standard
compaction equipment. We recommend that engineered fill be compacted to at least 95 percent of
the maximum dry density determined by ASTM D698 (Standard Proctor) or equivalent. Field
density testing should conform to ASTM D2922 and D3017, or D1556. All engineered fill should be
observed and tested by the project geotechnical engineer or his representative. Typically, one
density test is performed for at least every 2 vertical feet of fill placed or every 500 yd3, whichever
requires more testing. Because testing is performed on an on-call basis, we recommend that the
earthwork contractor be held contractually responsible for test scheduling and frequency. During
periods of wet-weather site earthwork may be impacted by soil moisture.
Excavating Conditions and Utility Trench Backfill
We anticipate that on-site soils can generally be excavated using conventional heavy equipment.
Bedrock was not encountered within our soil borings which extended to a maximum depth of 41.5
feet bgs. Maintenance of safe working conditions, including temporary excavation stability, is the
responsibility of the contractor. Actual slope inclinations at the time of construction should be
determined based on safety requirements and actual soil and groundwater conditions. All
temporary cuts in excess of 4 feet in height should be sloped in accordance with U.S. Occupational
Safety and Health Administration (OSHA) regulations (29 CFR Part 1926), or be shored. The
existing native soils classify as Type B Soil and temporary excavation side slope inclinations as
steep as 1 H:1 V may be assumed for planning purposes. These cut slope inclinations are
applicable to excavations above the water table only.
Shallow, perched groundwater may be encountered during the wet weather season and should be
anticipated in excavations and utility trenches. Vibrations created by traffic and construction
equipment may cause some caving and raveling of excavation walls. In such an event, lateral
support for the excavation walls should be provided by the contractor to prevent loss of ground
support and possible distress to existing or previously constructed structural improvements.
Underground utility pipe should be installed in accordance with the procedures specified in ASTM
D2321 and City of Tigard standards. We recommend that structural trench backfill be compacted
to at least 95 percent of the maximum dry density obtained by the Standard Proctor (ASTM D698)
or equivalent. Initial backfill lift thicknesses for a 3/"-0 crushed aggregate base may need to be as
great as 4 feet to reduce the risk of flattening underlying flexible pipe. Subsequent lift thickness
should not exceed 1 foot. If imported granular fill material is used, then the lifts for large vibrating
plate-compaction equipment (e.g. hoe compactor attachments) may be up to 2 feet, provided that
proper compaction is being achieved and each lift is tested. Use of large vibrating compaction
equipment should be carefully monitored near existing structures and improvements due to the
potential for vibration-induced damage.
Adequate density testing should be performed during construction to verify that the recommended
relative compaction is achieved. Typically, at least one density test is taken for every 4 vertical feet
of backfill on each 100-lineal-foot section of trench.
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Erosion Control Considerations
During our field exploration program, we did not observe soil conditions that would be considered
highly susceptible to erosion. In our opinion, the primary concern regarding erosion potential will
occur during construction in areas that have been stripped of vegetation. Erosion at the site during
construction can be minimized by implementing the project erosion control plan, which should
include judicious use of straw waddles, fiber rolls, and silt fences. If used, these erosion control
devices should remain in place throughout site preparation and construction.
Erosion and sedimentation of exposed soils can also be minimized by quickly re-vegetating
exposed areas of soil, and by staging construction such that large areas of the project site are not
denuded and exposed at the same time. Areas of exposed soil requiring immediate and/or
temporary protection against exposure should be covered with either mulch or erosion control
netting/blankets. Areas of exposed soil requiring permanent stabilization should be seeded with an
approved grass seed mixture, or hydroseeded with an approved seed-mulch-fertilizer mixture.
Wet Weather Earthwork
Soils underlying the site are likely to be moisture sensitive and may be difficult to handle or
traverse with construction equipment during periods of wet weather. Earthwork is typically most
economical when performed under dry weather conditions. Earthwork performed during the
wet-weather season will probably require expensive measures such as cement treatment or
imported granular material to compact areas where fill may be proposed to the recommended
engineering specifications. If earthwork is to be performed or fill is to be placed in wet weather or
under wet conditions when soil moisture content is difficult to control, the following
recommendations should be incorporated into the contract specifications.
• Earthwork should be performed in small areas to minimize exposure to wet weather.
Excavation or the removal of unsuitable soils should be followed promptly by the placement
and compaction of clean engineered fill. The size and type of construction equipment used
may have to be limited to prevent soil disturbance. Under some circumstances, it may be
necessary to excavate soils with a backhoe to minimize subgrade disturbance caused by
equipment traffic;
• The ground surface within the construction area should be graded to promote run-off of
surface water and to prevent the ponding of water;
• Material used as engineered fill should consist of clean, granular soil containing less than 5
percent passing the No. 200 sieve. The fines should be non-plastic. Alternatively, cement
treatment of on-site soils may be performed to facilitate wet weather placement;
• The ground surface within the construction area should be sealed by a smooth drum
vibratory roller, or equivalent, and under no circumstances should be left uncompacted and
exposed to moisture. Soils which become too wet for compaction should be removed and
replaced with clean granular materials;
• Excavation and placement of fill should be observed by the geotechnical engineer to verify
that all unsuitable materials are removed and suitable compaction and site drainage is
achieved; and
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• Geotextile silt fences, straw waddles, and fiber rolls should be strategically located to
control erosion.
If cement or lime treatment is used to facilitate wet weather construction, GeoPacific should be
contacted to provide additional recommendations and field monitoring.
Spread Foundations
Based upon communication with the client, and review of preliminary project plans, GeoPacific
understands that the proposed development at the site will consist of construction of a five-story,
mixed-use building, with retail and parking spaces on the ground level, and multi-family residential
units on the upper levels. The building will have a footprint of approximately 9,906 square-feet,
and will be located on the western portion of the site (see Figure 3). We anticipate that site grading
will include cuts and fills which will be on the order of five feet or less.
Based upon review of information provided by Hill Architects, it is our understanding that the
proposed building will be designed as Type V construction, with slab-on-grade, post and pier, or
spread footing foundations on the ground level, a post-tensioned concrete slab at the second level,
and wood framing above. Based upon structural loading information provided by DCI Engineers
(see Figure 4), we anticipate maximum structural loading on column footings and continuous strip
footings on the order of 100 to 225 kips, and 4 to 10 kips respectively.
Based on our calculations and analyses, without ground improvement, we estimate that 2 to 3
inches of static settlement could occur. With ground improvement, such as the installation of
Geopier elements, the magnitude of static settlement can be reduced to tolerable levels. It is our
understanding that Geopier elements are to be installed on a grid pattern within the footprint of the
proposed structure, with additional piers underneath foundation components as needed. A row of
piers is also proposed around the perimeter of the structure. GeoPacific has reviewed design
documents by the aggregate pier design/build contractor, Geopier Northwest. Geopier northwest
estimates that total settlement(static)will be less than one inch and differential settlement will most
likely be less than one-half inch. We anticipate that the majority of the estimated settlement will
occur during construction, as loads are applied.
The proposed structures may be supported on shallow foundations bearing on native soils which
have been improved by the installation of Geopier elements. Engineered fill material placed over
the improved native soil should meet the requirements of the Geopier design/build contractor.
Foundation design, construction, and setback requirements should conform to the applicable
building code at the time of construction. For maximization of bearing strength and protection
against frost heave, spread footings should be embedded at a minimum depth of 18 inches below
exterior grade. If soft soil conditions are encountered at footing subgrade elevation, they should be
removed and replaced with compacted crushed aggregate.
For footings bearing directly on native soil that has been improved by the installation of engineered
aggregate piers (EAPs), and for footings bearing on granular engineered fill placed and compacted
over native soil that has been improved by the installation of EAPs, the anticipated allowable soil
bearing pressure should be capped at 4,000 psf. For footings that are bearing on fine-grained
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engineered fill material placed and compacted over native soil that has been improved by the
installation of EAPs, the anticipated allowable soil bearing pressure should be limited 2,000 psf.
Footing excavations should penetrate through topsoil and any disturbed soil to competent
subgrade that is suitable for bearing support. All footing excavations should be trimmed neat, and
all loose or softened soil should be removed from the excavation bottom prior to placing reinforcing
steel bars. Due to the moisture sensitivity of on-site native soils, foundations constructed during
the wet weather season may require over-excavation of footings and backfill with compacted,
crushed aggregate. Appropriate recommendations can be made for wet weather foundation
construction, if needed during construction.
Wind, earthquakes, and unbalanced earth loads will subject the proposed structure to lateral
forces. Lateral forces on a structure will be resisted by a combination of sliding resistance of its
base or footing on the underlying soil and passive earth pressure against the buried portions of the
structure. For use in design, a coefficient of friction of 0.42 may be assumed along the interface
between the base of the footing and subgrade soils. Passive earth pressure for buried portions of
structures may be calculated using an equivalent fluid weight of 320 pounds per cubic foot (pcf),
assuming footings are cast against dense, natural soils or engineered fill. The recommended
coefficient of friction and passive earth pressure values do not include a safety factor. The upper
12 inches of soil should be neglected in passive pressure computations unless it is protected by
pavement or slabs on grade.
Our recommendations are intended only for the above described structure. After site development,
a Final Soil Engineer's Report should either confirm or modify the above recommendations.
Concrete Slabs-on-Grade
Preparation of areas beneath concrete slab-on-grade floors should be performed as recommended
in the Site Preparation Recommendations section. Care should be taken during excavation for
foundations and floor slabs, to avoid disturbing subgrade soils. If subgrade soils have been
adversely impacted by wet weather or otherwise disturbed, the surficial soils should be scarified to
a minimum depth of 8 inches, moisture conditioned to within about 3 percent of optimum moisture
content, and compacted to engineered fill specifications. Alternatively, disturbed soils may be
removed and the removal zone backfilled with additional crushed rock.
For evaluation of the concrete slab-on-grade floors using the beam on elastic foundation method, a
modulus of subgrade reaction of 150 kcf (87 pci) should be assumed for the medium stiff,
fine-grained soils anticipated to be present in the upper four feet at the site. This value assumes
the concrete slab system is designed and constructed as recommended herein, with a minimum
thickness of 8 inches of 1 W-0 crushed aggregate beneath the slab. The total thickness of crushed
aggregate will be dependent on the subgrade conditions at the time of construction, and should be
verified visually by proof-rolling. Under-slab aggregate should be compacted to at least 90 percent
of its maximum dry density as determined by ASTM D1557 (Modified Proctor) or equivalent.
In areas where moisture will be detrimental to floor coverings or equipment inside the proposed
structure, appropriate vapor barrier and damp-proofing measures should be implemented. A
commonly applied vapor barrier system consists of a 10-mil polyethylene vapor barrier placed
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directly over the capillary break material. Other damp/vapor barrier systems may also be feasible.
Appropriate design professionals should be consulted regarding vapor barrier and damp proofing
systems, ventilation, building material selection and mold prevention issues, which are outside
GeoPacific's area of expertise.
Footing and Roof Drains
Construction should include typical measures for controlling subsurface water beneath the
buildings, including positive crawlspace drainage to an adequate low-point drain exiting the
foundation, visqueen covering the expose ground in the crawlspace, and crawlspace ventilation
(foundation vents). The client should be informed and educated that some slow flowing water in
the crawlspaces is considered normal and not necessarily detrimental to the structure given these
other design elements incorporated into its construction. Appropriate design professionals should
be consulting regarding crawlspace ventilation, building material selection and mold prevention
issues, which are outside GeoPacific's area of expertise.
Down spouts and roof drains should collect roof water in a system separate from the footing drains
to reduce the potential for clogging. Roof drain water should be directed to an appropriate
discharge point and storm system well away from structural foundations. Grades should be sloped
downward and away from buildings to reduce the potential for ponded water near structures.
Perimeter footing drains should consist of 3 or 4-inch diameter, perforated plastic pipe embedded
in a minimum of 1 ft3 per lineal foot of clean, free-draining drain rock. The drain pipe and
surrounding drain rock should be wrapped in non-woven geotextile (Mirafi 140N, or approved
equivalent) to minimize the potential for clogging and/or ground loss due to piping. A minimum 0.5
percent fall should be maintained throughout the drain and non-perforated pipe outlet. Figure 5
presents a typical perimeter footing drain detail. In our opinion, footing drains may outlet at the
curb, or on the back sides of lots where sufficient fall is not available to allow drainage to meet the
street.
Permanent Below-Grade Walls
Lateral earth pressures against below-grade retaining walls will depend upon the inclination of any
adjacent slopes, type of backfill, degree of wall restraint, method of backfill placement, degree of
backfill compaction, drainage provisions, and magnitude and location of any adjacent surcharge
loads. At-rest soil pressure is exerted on a retaining wall when it is restrained against rotation. In
contrast, active soil pressure will be exerted on a wall if its top is allowed to rotate or yield a
distance of roughly 0.001 times its height or greater.
If the subject retaining walls will be free to rotate at the top, they should be designed for an active
earth pressure equivalent to that generated by a fluid weighing 40 pcf for level backfill against the
wall. For restrained wall, an at-rest equivalent fluid pressure of 55 pcf should be used in design,
again assuming level backfill against the wall. These values assume that the recommended
drainage provisions are incorporated, and hydrostatic pressures are not allowed to develop against
the wall.
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During a seismic event, lateral earth pressures acting on below-grade structural walls will increase
by an incremental amount that corresponds to the earthquake loading. Based on the
Mononobe-Okabe equation and peak horizontal accelerations appropriate for the site location,
seismic loading should be modeled using the active or at-rest earth pressures recommended
above, plus an incremental rectangular-shaped seismic load of magnitude 6.5H, where H is the
total height of the wall.
We assume relatively level ground surface below the base of the walls. As such, we recommend
passive earth pressure of 300 pcf for use in design, assuming wall footings are cast against
competent native soils or engineered fill. If the ground surface slopes down and away from the
base of any of the walls, a lower passive earth pressure should be used and GeoPacific should be
contacted for additional recommendations.
A coefficient of friction of 0.42 may be assumed along the interface between the base of the wall
footing and subgrade soils. The recommended coefficient of friction and passive earth pressure
values do not include a safety factor, and an appropriate safety factor should be included in design.
The upper 12 inches of soil should be neglected in passive pressure computations unless it is
protected by pavement or slabs on grade.
The above recommendations for lateral earth pressures assume that the backfill behind the
subsurface walls will consist of properly compacted structural fill, and no adjacent surcharge
loading. If the walls will be subjected to the influence of surcharge loading within a horizontal
distance equal to or less than the height of the wall, the walls should be designed for the additional
horizontal pressure. For uniform surcharge pressures, a uniformly distributed lateral pressure of
0.3 times the surcharge pressure should be added. Traffic surcharges may be estimated using an
additional vertical load of 125 to 250 psf (1 to 2 feet of additional fill), depending on anticipated
traffic loads.
The recommended equivalent fluid densities assume a free-draining condition behind the walls so
that hydrostatic pressures do not build-up. This can be accomplished by placing a 12 to 18-inch
wide zone of sand and gravel containing less than 5 percent passing the No. 200 sieve against the
walls. A 3-inch minimum diameter perforated, plastic drain pipe should be installed at the base of
the walls and connected to a suitable discharge point to remove water in this zone of sand and
gravel. The drain pipe should be wrapped in filter fabric (Mirafi 140N or other as approved by the
geotechnical engineer) to minimize clogging.
Wall drains are recommended to prevent detrimental effects of surface water runoff on foundations
— not to dewater groundwater. Drains should not be expected to eliminate all potential sources of
water entering a basement or beneath a slab-on-grade. An adequate grade to a low point outlet
drain in the crawlspace is required by code. Underslab drains are sometimes added beneath the
slab when placed over soils of low permeability and shallow, perched groundwater.
Water collected from the wall drains should be directed into the local storm drain system or other
suitable outlet. A minimum 0.5 percent fall should be maintained throughout the drain and non-
perforated pipe outlet. Down spouts and roof drains should not be connected to the wall drains in
order to reduce the potential for clogging. The drains should include clean-outs to allow periodic
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maintenance and inspection. Grades around the proposed structure should be sloped such that
surface water drains away from the building.
GeoPacific should be contacted during construction to verify subgrade strength in wall keyway
excavations, to verify that backslope soils are in accordance with our assumptions, and to take
density tests on the wall backfill materials.
Structures should be located a horizontal distance of at least 1.5H away from the back of the
retaining wall, where H is the total height of the wall. GeoPacific should be contacted for additional
foundation recommendations where structures are located closer than 1.5H to the top of any wall.
Stormwater Management
We understand that it is desired to incorporate subsurface infiltration of stormwater into the design
of stormwater management facilities. However, the soils encountered in our explorations exhibited
negligible infiltration rates (zero inches per hour). Also, we encountered groundwater at depths of
12.5 to 15 feet bgs. Based on the subsurface conditions encountered, subsurface infiltration of
stormwater is not recommended for this site.
Stormwater management systems should be constructed as specified by the designer and/or in
accordance with jurisdictional design manuals. Stormwater exceeding storage capacities will need
to be directed to a suitable surface discharge location, away from structures. Stormwater
management systems may need to include overflow outlets, surface water control measures and/or
be connected to the street storm drain system, if available. In no case should uncontrolled
stormwater be allowed to flow over slopes.
PAVEMENT EVALUATION AND DESIGN
GeoPacific conducted an evaluation of the existing pavement sections in the eastern lane of SW
72"d Avenue along the frontage of the property, new flexible pavement design for widening of SW
72" Avenue along the frontage of the property, and new flexible and rigid pavement design for
construction of private parking areas and drive lanes within the development. The results of our
pavement analysis and design are presented below.
SW 72"d Avenue— East Lane: Existing Pavement Evaluation
The existing pavement in the east lane (northbound) of SW 72nd Avenue was found to be in
relatively good condition. During the investigation, we did not observe evidence of heavy wear or
damage such as extensive rutting, or cracking. Minor transverse cracks were observed in some
locations. In the pavement cores drilled in the east lane of SW 72" Avenue along the frontage of
the property, we encountered 6.5 to 10.5 inches of existing asphalt. Beneath the asphalt we
encountered 4 to 7 inches of 1.5"-0 basaltic crushed aggregate. Subgrade soils underlying the
base aggregate were found to consist of stiff, moist, Lean CLAY. Table 2 summarizes our
collected data from the investigation.
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Table 2 - Summary of Existing Pavement Sections in Exploratory Pavement Cores
Road Core Designation Total Pavement Base Rock Subgrade
Thickness(in) Thickness(in)
RC-1 10.5 5 Lean CLAY(CL)
RC-2 10 4 Lean CLAY(CL)
RC-3 6.5 7 Lean CLAY(CL)
We performed in-place field testing of subgrade soil strength at the pavement core locations using
a portable dynamic cone penetrometer (PDCP). Table 3 summarizes the results of our PDCP
testing.
Table 3 - PDCP Field Test Results and Representative CBR Values
Field Test Depth Interval of Average Correlated CBR
Material Tested Penetration Per
Designation Test(inches) Value
Blow(mm)
RC-1 Lean CLAY(CL) 17.75-38.5 41.28 10.55
RC-2 Lean CLAY(CL) 18.0-35.5 37.34 5.66
RC-3 Lean CLAY(CL) 16.25-30.25 8.0 42
Based on the results of PDCP testing, we estimate that the subgrade exhibits a resilient modulus
ranging from 7,500 psi to 63,000 psi. For analysis and design purposes, we assume that the
subgrade exhibits a resilient modulus of 7,500 psi, which correlates to a CBR value of 5, the lowest
of values measured during our investigation. PDCP calculations are attached to this report.
Based upon the results of our pavement investigation we analyzed the existing section of the east
lane (northbound) of SW 72nd Avenue along the frontage of the property for 20-years of remaining
design life. Based upon City of Tigard, Oregon 2016 Traffic Count Data for SW 72nd Avenue and
Baylor Street, we assumed an Average Daily Traffic Count (ADT) of 4,250. Traffic count data is
attached to this report. We assume that traffic will primarily consist of light duty residential cars,
and eight percent heavy trucks, school-buses-and occasional fire trucks weighing up to 75,000 lbs.
Anticipated traffic was calculated over 20 years-assuming-3-percent population growth per year.
Based upon our understanding of the anticipated vehicle traffic in the east lane of SW 72nd Avenue
along the frontage of the property, we calculated an 18-kip ESAL count of approximately 3,829,800
over 20 years. Tables 4 through 6 present our flexible pavement design input factors and required
structural numbers to support 20 years of remaining design life for SW 72nd Avenue at each
pavement core location. Pavement design calculations are presented in the appendix of this report.
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Table 4—Flexible Pavement Section Design Input Factors for SW 72nd Avenue
Existing Pavement Core RC-1
Il
Input Parameter Design Value
18-kip ESAL Initial Performance Period(20 Years) 3,829,800
Initial Serviceability 4.2
Terminal Serviceability 2.5
Reliability Level 90 Percent
Overall Standard Deviation 0.5
Roadbed Soil Resilient Modulus(PSI) 15,000
Structural Number 3.41
Table 5—Flexible Pavement Section Design Input Factors for SW 72nd Avenue
Existing Pavement Core RC-2
e
Input Parameter Design Value
18-kip ESAL Initial Performance Period(20 Years) 3,829,800
Initial Serviceability 4.2
Terminal Serviceability 2.5
Reliability Level 90 Percent
Overall Standard Deviation 0.5
Roadbed Soil Resilient Modulus(PSI) 7,500
Structural Number 4.40
Table 6—Flexible Pavement Section Design Input Factors for SW 72nd Avenue
Existing Pavement Core RC-3
Input Parameter Design Value
18-kip ESAL Initial Performance Period(20 Years) 3,829,800
Initial Serviceability 4.2
Terminal Serviceability 2.5
Reliability Level 90 Percent
Overall Standard Deviation 0.5
Roadbed Soil Resilient Modulus(PSI) 50,000
Structural Number 2.14
Tables 7 through 9 present our data from core locations of the existing pavement section with
estimated structural coefficients calculated into a structural number. Pavement design calculations
are attached to this report.
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Table 7-Analyzed Section of Existing Asphalt Pavement of SW 175th Avenue- RC-1
Material Layer Section Thickness(in.) Structural Coefficient
Existing Asphaltic Concrete(AC) 10.5 4.20
1.5"-0 Crushed Aggregate Base 5 0.50
Subgrade Lean CLAY 15,000 PSI
Calculated Structural Number 4.70
Table 8-Analyzed Section of Existing Asphalt Pavement of SW 175th Avenue- RC-2
Material Layer Section Thickness(in.) Structural Coefficient
Existing Asphaltic Concrete(AC) 10 4.0
1.5"-0 Crushed Aggregate Base 4 0.40
Subgrade Lean CLAY 7,500 PSI
Calculated Structural Number 4.40
Table 9-Analyzed Section of Existing Asphalt Pavement of SW 175th Avenue- RC-3
Material Layer Section Thickness(in.) Structural Coefficient
Existing Asphaltic Concrete(AC) 6.5 2.6
1.5"-0 Crushed Aggregate Base 7 0.70
Subgrade Lean CLAY 50,000 PSI
Calculated Structural Number 3.30
Based upon the observed conditions and structural analysis of the existing pavement section at the
east lane (northbound) of SW 72"d Avenue along the frontage of the property, the existing asphalt
and pavement section appears to be suitable for supporting anticipated traffic loading for a 20-year
period.
SW 72' Avenue: New Pavement-Design For Street Widening
We understand that the eastern margin of SW 72nd Avenue will be widened along the frontage of
the property. For the new pavement section we conservatively assume that the subgrade will
exhibit a resilient modulus of at least 7,500, which correlates to a CBR value of 5. Based upon City
of Tigard, Oregon 2016 Traffic Count Data for SW 72nd Avenue and Baylor Street, we assumed an
Average Daily Traffic Count (ADT) of 4,250. Traffic count data is attached to this report. We
assume that traffic will primarily consist of light duty residential cars, and eight percent heavy
trucks, school buses and occasional fire trucks weighing up to 75,000 lbs. Anticipated traffic was
calculated over 20 years assuming 3 percent population growth per year. Based upon our
understanding of the anticipated vehicle traffic in the east lane of SW 72nd Avenue along the
frontage of the property, we calculated an 18-kip ESAL count of approximately 3,829,800 over 20
years. Table 10 presents our flexible pavement design input parameters. Table 11 presents our
recommended minimum dry-weather pavement section for the proposed roadway, supporting 20
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years of vehicle traffic per City of Tigard, Oregon standards. Pavement design calculations are
attached to this report.
Table 10—Flexible Pavement Section Design Input Factors for SW 72nd Avenue
Input Parameter Design Value
18-kip ESAL Initial Performance Period (20 Years) 3,829,800
Initial Serviceability 4.2
Terminal Serviceability 2.5
Reliability Level 90 Percent
Overall Standard Deviation 0.5
Roadbed Soil Resilient Modulus(PSI) 7,500
Structural Number 4.40
Table 11 - Recommended Minimum Dry-Weather Pavement Section
SW 72nd Avenue, East Lane Widening
Section Thickness Structural
Material Layer (in.) Coefficient Compaction Standard
92%of Rice Density
Asphaltic Concrete(AC) 8 0.42 AASHTO T-209
Crushed Aggregate Base 2 10 95% of Modified Proctor
%"-0(leveling course) AASHTO T-180
Crushed Aggregate Base 95%of Modified Proctor
1'W-0 10 .10 AASHTO T-180
Subgrade 12 7,500 PSI 95%of Standard Proctor
AASHTO T-99 or equivalent
Calculated Structural Number 4.36
Flexible Pavement Design — Private Parking Areas
We understand that development at the site will include construction of private parking and drive
areas surfaced with asphalt. For the new flexible private pavement section, we conservatively
assume that the subgrade will exhibit a resilient modulus of at least 7,500, which correlates to a
CBR value of 5. Based upon our understanding of the anticipated traffic which includes light-duty
passenger vehicles, weekly trash pickups, and occasional fire trucks weighing up to 75,000 lbs, we
calculated an anticipated 18-kip ESAL count of approximately 100,000 over 20 years. Table 12
presents our flexible pavement design input parameters. Table 13 presents our recommended
minimum dry-weather pavement section for the proposed pavement section, supporting 20 years
of vehicle traffic. Pavement design calculations are attached to this report.
17-4626,72nd Avenue Apartments GRPTv2 20 GEOPACIFIC ENGINEERING, INC.
Version 2.0,August 20,2018
Geotechnical Engineering Report 6OOP
Project No. 17-4626, 72nd Avenue Apartments, Tigard, Oregon InnMeering,Inc.
Table 12- Flexible Pavement Section Design Input Parameters for Private Parking and Drive Areas
Input Parameter Design Value
18-kip ESAL Initial Performance Period 100,000
(20 Years)
Initial Serviceability 4.2
Terminal Serviceability 2.5
Reliability Level 90 Percent
Overall Standard Deviation 0.5
Roadbed Soil Resilient Modulus(PSI) 7,500
Structural Number 2.43
Table 13 - Recommended Minimum Dry-Weather Pavement Section for Private Parking and Drive Areas
Material Layer Section Thickness Structural Compaction Standard
(in.) Coefficient
Asphaltic Concrete(AC) 3.5 in. .42 91%/92%of Rice Density
AASHTO T-209
Crushed Aggregate Base%"-0 95% of Modified Proctor
(leveling course) 2 in. .10 AASHTO T-180
Crushed Aggregate Base 1'/2"-0 8 in. .10 95%of Modified Proctor
AASHTO T-180
Subgrade 12 in. 7,500 PSI 95% of Standard Proctor
AASHTO T-99 or equivalent
Total Calculated Structural Number 2.47
Rigid Pavement Design - Private Parking and Drive Areas
We understand that portions of the proposed private parking and drive areas will be constructed
with Portland cement concrete (PCC) pavement. For the new private rigid pavement section, we
conservatively assume that the subgrade will exhibit a resilient modulus of at least 7,500, which
correlates to a CBR value of 5. Based upon our understanding of the anticipated traffic which
includes light-duty passenger vehicles, weekly trash pickups, and occasional fire trucks weighing
up to 75,000 lbs, we calculated an_anticipated 18-kip ESAL count of approximately 100,000 over
20 years.
We anticipate that near surface soils which may become disturbed during construction, or which
are observed to pump and rut, will be over-excavated and backfilled with granular engineered fill.
Under these assumptions, a PCC slab thickness of 6 inches is adequate. Therefore, our
recommended pavement design is 6 inches of 4,000 psi minimum compressive strength concrete
over 8 inches of crushed aggregate base rock, over an undisturbed, competent subgrade or
engineered fill. Table 14 presents the recommended minimum road section for the proposed rigid
pavement. Pavement design calculations are attached to this report.
17-4626,72nd Avenue Apartments GRPTv2 21 GEOPACIFIC ENGINEERING, INC.
Version 2.0,August 20,2018
Geotechnical Engineering Report GeoPacitic
Project No. 17-4626, 72nd Avenue Apartments, Tigard, Oregon c. ii
Table 14—Flexible Pavement Section Design Input Parameters for Parking and Drive Areas
Section
Material Layer Thickness Standard
(in
Concrete should be sampled and tested per
Portland Cement Concrete the requirements of ACI 318.
Pavement
4,000 psi 6 4,000 psi compressive strength at 28 days
(PCC) Maximum Air Content 4 percent.
Maximum Slump 6 inches.
Crushed Aggregate Base2 95% of Modified Proctor
3/"-0 (leveling course) ASTM D1557
Crushed Aggregate Base 95% of Modified Proctor
1W-0 6 ASTM D1557
Competent Subgrade N/A Visual Inspection (Proofroll)
Subclrade Preparation
The roadway and parking area subgrade should be compacted and inspected by GeoPacific prior
to the placement of crushed aggregate base for pavement. Typically, a proofroll with a fully loaded
water or haul truck is conducted by travelling slowly across the grade and observing the subgrade
for rutting, deflection, or movement. Any pockets of organic debris or loose fill encountered during
ripping or tilling should be removed and replaced with engineered fill (see Site Preparation
Recommendations section). In order to verify subgrade strength, we recommend proof-rolling
directly on subgrade with a loaded dump truck during dry weather and on top of base course in wet
weather. Soft areas that pump, rut, or weave should be stabilized prior to paving.
If pavement areas are to be constructed during wet weather, the subgrade and construction plan
should be reviewed by the project geotechnical engineer at the time of construction so that
condition specific recommendations can be provided. The moisture sensitive subgrade soils make
the site a difficult wet weather construction project. General recommendations for wet weather
pavement sections are provided below.
During placement of pavement section materials, density testing should be performed to verify
compliance with project specifications. Generally, one subgrade, one base course, and one
asphalt compaction test is performed for every 100 to 200 linear feet of paving.
Wet Weather Construction Pavement Section
This section presents our recommendations for wet weather pavement sections and construction
for new pavement sections at the project. These wet weather pavement section recommendations
are intended for use in situations where it is not feasible to compact the subgrade soils to project
requirements, due to wet subgrade soil conditions, and/or construction during wet weather. Based
on our site review, we recommend a wet weather section with a minimum subgrade deepening of 6
to 12 inches to accommodate a working subbase of additional 11/2"-0 crushed rock. Geotextile
fabric, Mirafi 500x or equivalent, should be placed on subgrade soils prior to placement of base
rock.
17-4626,72nd Avenue Apartments GRPTv2 22 GEOPACIFIC ENGINEERING, INC.
Version 2.0,August 20,2018
Geotechnical Engineering Report GeoPacific
Project No. 17-4626, 72nd Avenue Apartments, Tigard, Oregon Eaaneettag.tnc.
In some instances, it may be preferable to use a subbase material in combination with over-
excavation and increasing the thickness of the rock section. GeoPacific should be consulted for
additional recommendations regarding use of additional subbase in wet weather pavement
sections if it is desired to pursue this alternative. Cement treatment of the subgrade may also be
considered instead of over-excavation. For planning purposes, we anticipate that treatment of the
onsite soils would involve mixing cement powder to approximately 6 percent cement content and a
mixing depth on the order of 12 to 18 inches.
With implementation of the above recommendations, it is our opinion that the resulting pavement
section will provide equivalent or greater structural strength than the dry weather pavement section
currently planned. However, it should be noted that construction in wet weather is risky and the
performance of pavement subgrades depend on a number of factors including the weather
conditions, the contractor's methods, and the amount of traffic the road is subjected to. There is a
potential that soft spots may develop even with implementation of the wet weather provisions
recommended in this letter. If soft spots in the subgrade are identified during roadway excavation,
or develop prior to paving, the soft spots should be over-excavated and backfilled with additional
crushed rock.
During subgrade excavation, care should be taken to avoid disturbing the subgrade soils.
Removals should be performed using an excavator with a smooth-bladed bucket. Truck traffic
should be limited until an adequate working surface has been established. We suggest that the
crushed rock be spread using bulldozer equipment rather than dump trucks, to reduce the amount
of traffic and potential disturbance of subgrade soils. Care should be taken to avoid over-
compaction of the base course materials, which could create pumping, unstable subgrade soil
conditions. Heavy and/or vibratory compaction efforts should be applied with caution. Following
placement and compaction of the crushed rock to project specifications (95 percent of Modified
Proctor), a finish proof-roll should be performed before paving.
The above recommendations are subject to field verification. GeoPacific should be on-site during
construction to verify subgrade strength and to take density tests on the engineered fill, base rock
and asphaltic pavement materials.
SEISMIC DESIGN
The Oregon Department of Geology and Mineral Industries (DOGAMI), Oregon HazVu: 2017
Statewide GeoHazards Viewer indicates that the site is in an area where very strong ground
shaking is anticipated during an earthquake. Structures should be designed to resist earthquake
loading in accordance with the methodology described in the 2015 International Building Code
(IBC) with applicable Oregon Structural Specialty Code (OSSC) revisions (current 2014).
Assuming that the recommendations for ground improvement are followed, we recommend Site
Class D be used for design per the OSSC, Table 1613.5.2 and as defined in ASCE 7, Chapter 20,
Table 20.3-1. Design values determined for the site using the USGS (United States Geological
Survey) 2017 Seismic Design Maps Summary Report are summarized in Table 15.
17-4626,72nd Avenue Apartments GRPTv2 23 GEOPACIFIC ENGINEERING, INC.
Version 2.0,August 20,2018
. `fir
Geotechnical Engineering Report GeoPac`itic
Project No. 17-4626, 72nd Avenue Apartments, Tigard, Oregon £u$needa.Inc.
Table 15- Recommended Earthquake Ground Motion Parameters (USGS 2017)
Parameter Value
Location (Lat, Long), degrees 45.435, -122.750
Probabilistic Ground Motion Values,
2% Probability of Exceedance in 50 yrs
Peak Ground Acceleration PGAM 0.459 g
Short Period, Ss 0.981 g
1.0 Sec Period, Si 0.424 g
Soil Factors for Site Class D:
Fa 1.108
Fv 1.576
SDs =2/3 x Fa x Ss 0.724 g
SDi =2/3xFvxSi 0.445g
Seismic Design Category D
Soil Liquefaction
The Oregon Department of Geology and Mineral Industries (DOGAMI), Oregon HazVu: 2017
Statewide GeoHazards Viewer indicates that the site contains areas considered to be at low risk
for soil liquefaction during an earthquake. However, the site is bordering a large area to the west
which DOGAMI has identified to be at high risk for soil liquefaction during an earthquake. Soil
liquefaction is a phenomenon wherein saturated soil deposits temporarily lose strength and behave
as a liquid in response to ground shaking caused by strong earthquakes. Soil liquefaction typically
occurs in loose sands and granular soils located below the water table, and fine-grained soils with
a plasticity index less than 15, and SPT N-Values lower than 15.
The subsurface profile observed within our subsurface explorations, which extended to a maximum
depth of 53.2 feet bgs, indicated that the site is underlain by medium stiff to stiff, low to moderately
plastic, Lean CLAY; soft to medium stiff, low plasticity SILT; stiff, highly plastic, Elastic SILT (MH);
and stiff, highly plastic, Fat CLAY (CH). On July 3, 2017, observed soil moisture conditions were
generally very moist to wet. Groundwater seepage was observed within our soil borings at depths
ranging from 12.5 to 15 feet bgs. Groundwater was encountered at a depth of 12.5 feet in CPT-1.
According to the Estimated Depth to Groundwater in the Portland, Oregon Area, (United States
Geological Survey, Snyder, 2017 website), groundwater may be encountered at an approximate
depth ranging from 10 to 20 feet below the ground surface.
The liquefaction potential at the subject site was analyzed for the soil profiles encountered within
soil boring B-1 using LiqSVs version 1.0.1.59, by Geologismiki, and in CPT exploration CPT-1
using the commercial Cliq computer program. For our analyses, we used the Idriss and Boulanger
2014 methodology. We assumed groundwater at a depth of 12.5 feet during the design seismic
event. Using a peak horizontal ground acceleration of 0.46g, and an earthquake moment
magnitude of 7.75 based upon data obtained from the U.S. Geological Survey (USGS) 2017
Earthquake Hazards Program, the factor of safety was less than 1 for some soil layers, indicating
the potential for liquefaction during an earthquake.
Soils meeting the criteria for potentially liquefiable soil layers during an earthquake at this site
include the non-plastic SILT soils located below the static groundwater table. Based upon our
analysis of the existing soil profile, potentially liquefiable layers are present in the layer of soft to
17-4626,72nd Avenue Apartments GRPTv2 24 GEOPACIFIC ENGINEERING, INC.
Version 2.0,August 20,2018
Geotechnical Engineering Report GeoPacific
Project No. 17-4626, 72nd Avenue Apartments, Tigard, Oregon Engineering.Inc.
medium stiff, low plasticity silt at depths ranging from 18 to 30 feet in CPT-1, 12.5 to 30 feet in
boring B-1, 12.5 to 24 feet in boring B-2, and 15 to 20 feet in boring B-3. See the attached boring
logs and CPT log for details.
It is our opinion that the layer of elastic SILT (MH) is not liquefiable due to its high plasticity and
stiffness. Elastic SILT (MH) was encountered from 30 to 40 feet in boring B-1, below a depth of 25
feet in boring B-2, and from 20 to 40 feet in boring B-3. The layer of fat CLAY (CH) underlying the
elastic SILT (MH) is also considered non-liquefiable.
Without improving the soil to reduce the liquefaction potential of subsurface soil layers for the
design earthquake event presented above, vertical dynamic settlement and lateral spreading
expected at the subject site due to soil liquefaction would be excessive. It is our opinion that
vertical dynamic settlement and lateral spreading can be sufficiently mitigated for the proposed
structure by the recommended installation of engineered aggregate piers (EAPs) as ground
improvement, as designed by Geopier Northwest. Engineered aggregate piers should be installed
in a grid pattern with adequate depth and spacing. Engineered aggregate pier depths of 25 feet
will generally be adequate, except for in the vicinity of boring B-1 and CPT-1. In the vicinity of
boring B-1 and CPT-1, we recommend a pier depth of at least 30 feet.
GeoPacific has reviewed design documents from Geopier Northwest. Geopier Northwest plans to
install aggregate piers in a grid pattern to densify the native soils and provide support for slabs.
Geopier also plans to install dedicated aggregate piers for support of foundation elements and to
install a row of aggregate piers around the perimeter of the building to aid in confinement. It is our
understanding that Geopier Northwest has designed the geopier system to sufficiently mitigate
lateral spreading and to limit differential seismic settlements to less than 2 inches over 30 feet.
It should be noted that the proposed ground improvement plan is focused on lowering the risk of
damage to the proposed structure only. In the design seismic event, significant vertical settlement
and/or lateral spreading may still occur outside the area of ground improvement, to the north, east,
south, and west of the proposed structure. To the west of the site, across SW 72nd Avenue, the
ground surface slopes down to a 12-foot-high rockery wall, for a total vertical relief of
approximately 18 to 19 feet. The rockery wall is located approximately 80 to 90 feet west of the
western edge of the proposed building. GeoPacific is not aware whether or not the existing
rockery wall on the west side of SW 72nd Avenue has adequate factors of safety for slope stability
in the design seismic event or if it has been designed to resist lateral spreading.
It is our opinion that the proposed ground improvement system consisting of engineered aggregate
piers will sufficiently lower the risk of damage to the proposed structure due to dynamic settlement
and lateral spreading.
17-4626,72nd Avenue Apartments GRPTv2 25 GEOPACIFIC ENGINEERING, INC.
Version 2.0,August 20,2018
Geotechnical Engineering Report GeoPacific
Project No. 17-4626, 72nd Avenue Apartments,Tigard,Oregon EngfneeNng.Inc.
UNCERTAINTIES AND LIMITATIONS
We have prepared this report for the owner and his/her consultants for use in design of this project
only. The conclusions and interpretations presented in this report should not be construed as a
warranty of the subsurface conditions. Experience has shown that soil and groundwater conditions
can vary significantly over small distances. Inconsistent conditions can occur between
explorations that may not be detected by a geotechnical study. If, during future site operations,
subsurface conditions are encountered which vary appreciably from those described herein,
GeoPacific should be notified for review of the recommendations of this report, and revision of
such if necessary.
Sufficient geotechnical monitoring, testing, and consultation should be provided during construction
to confirm that the conditions encountered are consistent with those indicated by subsurface
explorations. The checklist attached to this report outlines recommended geotechnical
observations and testing for the project. Recommendations for design changes will be provided
should conditions revealed during construction differ from those anticipated, and to verify that the
geotechnical aspects of construction comply with the contract plans and specifications.
Within the limitations of scope, schedule and budget, GeoPacific executed these services in
accordance with generally accepted professional principles and practices in the fields of
geotechnical engineering and engineering geology at the time the report was prepared. No
warranty, express or implied, is made. The scope of our work did not include environmental
assessments or evaluations regarding the presence or absence of wetlands or hazardous or toxic
substances in the soil, surface water, or groundwater at this site.
We appreciate this opportunity to be of service.
Sincerely,
GEOPACIFIC ENGINEERING, INC.
Y�U ykO1 jSIO
•erii 900 A
2
, 0
04.
414
Benjamin L. Cook, R.G. Benjamin G. Anderson, P.E.
Senior Geologist Senior Engineer
17-4626,72nd Avenue Apartments GRPTv2 26 GEOPACIFIC ENGINEERING, INC.
Geotechnical Engineering Report GeoPacific
Project No. 17-4626, 72nd Avenue Apartments, Tigard, Oregon InnMan.i Inc.
REFERENCES
Atwater, B.F., 1992, Geologic evidence for earthquakes during the past 2,000 years along the Copalis River,southern coastal
Washington:Journal of Geophysical Research,v.97, p. 1901-1919.
Carver, G.A., 1992, Late Cenozoic tectonics of coastal northern California:American Association of Petroleum Geologists-
SEPM Field Trip Guidebook, May,1992.
Gannet, Marshall W., and Caldwell, Rodney R., Generalized Geologic Map of the Willamette Lowland, U.S. Department of the
interior, U.S. Geological Survey, 1998.
Geologic Map of the Camas Quadrangle, Multnomah County, Oregon,and Clark County,Washington, U.S. Geological Survey,
Evarts and O'Connor,2008.
Geologic Map of the Vancouver Quadrangle, Phillips,W.M.,Washington Division of Geology and Earth Resources, Open File
Report 87-10, 1987.
Geomatrix Consultants, 1995, Seismic Design Mapping, State of Oregon: unpublished report prepared for Oregon Department
of Transportation, Personal Services Contract 11688,January 1995.
Goldfinger, C., KuIm, L.D.,Yeats, R.S.,Appelgate, B, MacKay, M.E.,and Cochrane, G.R., 1996,Active strike-slip faulting and
folding of the Cascadia Subduction-Zone plate boundary and forearc in central and northern Oregon: in Assessing
earthquake hazards and reducing risk in the Pacific Northwest,v. 1: U.S. Geological Survey Professional Paper 1560,
P. 223-256.
Lidar-Based Surficial Geologic Map of the Greater Portland Area, Clackamas, Columbia, Marion, Multnomah,Washington, and
Yamhill Counties, Oregon, and Clark County,Washington,State of Oregon Department of Geology and Mineral
Industries, Open File Report 0-12-02,2012.
Ma, L., Madin, I.P., Duplantis, S., and Williams, K.J., 2012, Lidar-based Surficial Geologic Map and Database of the Greater
Portland, Oregon, Area, Clackamas, Columbia, Marion, Multnomah, Washington, and Yamhill Counties, Oregon, and
Clark County,Washington, DOGAMI Open-File Report 0-12-02
Mabey, M.A., Madin, I.P., and Black G.L., 1996, Relative Earthquake Hazard Map of the Lake Oswego Quadrangle, Clackamas,
Multnomah and Washington Counties, Oregon: Oregon Department of Geology and Mineral Industries
Madin, I.P., 1990, Earthquake hazard geology maps of the Portland metropolitan area, Oregon: Oregon Department of Geology
and Mineral Industries Open-File Report 0-90-2,scale 1:24,000, 22 p.
Oregon Department of Geology and Mineral Industries,Statewide Geohazards Viewer,www.oregongeology.org/hazvu.
Oregon Department of Geology and Mineral Industries, Madin, Ian P., Ma, Lina,and Niewendorp, Clark A., Open-File Report 0-
08-06, Preliminary Geologic Map of the Linnton 7.5'Quadrangle, Multnomah and Washington Counties, Oregon, 2008.
Peterson, C.D., Darioenzo, M.E., Burns, S.F.,and Burris,W.K., 1993, Field trip guide to Cascadia paleoseismic evidence along
the northern California coast: evidence of subduction zone seismicity in the central Cascadia margin: Oregon
Geology, v. 55, p. 99-144.
United States Geological Survey, USGS Earthquake Hazards Program Website(earthquake.usgs.gov).
Unruh, J.R.,Wong, I.G., Bott,J.D., Silva,W.J., and Lettis,W.R., 1994,Seismotectonic evaluation: Scoggins Dam,Tualatin
Project, Northwest Oregon: unpublished report by William Lettis and Associates and Woodward Clyde Federal
Services, Oakland, CA,for U.S. Bureau of Reclamation, Denver CO(in Geomatrix Consultants, 1995).
Web Soil Survey, Natural Resources Conservation Service, United States Department of Agriculture 2015 website.
(http://websoilsurvey.nrcs.usda.gov/app/HomePage.htm.).
Werner, K.S., Nabelek, J.,Yeats, R.S., Malone, S., 1992,The Mount Angel fault: implications of seismic-reflection data and the
Woodburn, Oregon, earthquake sequence of August, 1990: Oregon Geology,v. 54, p. 112-117.
Wong, I. Silva,W., Bott,J.,Wright, D.,Thomas, P.,Gregor, N., Li., S., Mabey, M., Sojourner,A.,and Wang,Y.,2000,
Earthquake Scenario and Probabilistic Ground Shaking Maps for the Portland, Oregon, Metropolitan Area; State of
Oregon Department of Geology and Mineral Industries; Interpretative Map Series IMS-16
Yeats, R.S., Graven, E.P.,Werner, K.S., Goldfinger, C.,and Popowski,T., 1996,Tectonics of the Willamette Valley, Oregon: in
Assessing earthquake hazards and reducing risk in the Pacific Northwest,v. 1: U.S. Geological Survey Professional
Paper 1560, P. 183-222, 5 plates,scale 1:100,000.
Yelin,T.S., 1992,An earthquake swarm in the north Portland Hills(Oregon): More speculations on the seismotectonics of the
Portland Basin: Geological Society of America, Programs with Abstracts,v.24, no. 5, p. 92.
Snyder, D.T., 2008, Estimated Depth to Ground Water and Configuration of the Water Table in the Portland, Oregon Area: U.S.
Geological Survey Scientific Investigations Report 2008-5059, 41 p., 3 plates.
17-4626,72nd Avenue Apartments GRPTv2 27 GEOPACIFIC ENGINEERING, INC.
Version 2.0,August 20,2018
Geotechnical Engineering Report GeoPaci is
Project No. 17-4626, 72nd Avenue Apartments, Tigard, Oregon Engineering Inc.
CHECKLIST OF RECOMMENDED GEOTECHNICAL TESTING AND OBSERVATION
Item Procedure Timing By Whom Done
No.
Prior to beginning site Contractor, Developer,
1 Preconstruction meeting work Civil and Geotechnical
Engineers
2 Fill removal from site or Prior to mass stripping Soil Technician/
sorting and stockpiling Geotechnical Engineer
3 Stripping, aeration, and root During stripping Soil Technician
picking operations
Compaction testing of During filling, tested
4 engineered fill (95% of every 2 vertical feet Soil Technician
Standard Proctor)
Compaction testing of trench During backfilling,
5 backfill (95% of tested every 4 vertical Soil Technician
StandardProctor) feet for every 200 lineal
feet
6 Street Subgrade Inspection Prior to placing base Soil Technician
course
7 Base course compaction Prior to paving, tested
(95% of Modified Proctor) every 200 lineal feet Soil Technician
Footing Over-Excavation
8 Backfill, 1.5"-0 Crushed During Placement Soil Technician
Aggregate
(95% of Modified Proctor)
9 Final Geotechnical Engineer's Completion of project Geotechnical Engineer
Report
17-4626,72nd Avenue Apartments GRPTv2 28 GEOPACIFIC ENGINEERING, INC.
Version 2.0,August 20,2018
1/4.
.iNf --
Ceo P cific
Engineering,Inc.
Real-World Geotechnical Solutions
Investigation • Design • Construction Support
FIGURES
14835 SW 72nd Avenue Tel (503) 598-8445
Portland, Oregon 97224 Fax (503) 941-9281
_411(`Nv1/4. 14835 SW 72nd Avenue
GeoPacific Portland, Oregon 97224 TYPICAL PERIMETER FOOTING DRAIN DETAIL
Tel: (503)598-8445 Fax: (503)941-9281
FOOTING BACKFILL ZONE NATIVE SOIL
FOOTING
\ :::•::,:•:::,:•;::,:-:.::,:•:.::,:-:.::,:•:.::,:•:::::•:::,:•:::,:•:::,:•:::,:-:::,:•:.:
.14" •��i :4•a ..4
. 1,
or
A.
/'
j
NON-WOVEN GEOTEXTILE FABRIC
PERFORATED OR SLOTTED 3-INCH, FREE DRAINING, OPEN GRADED MIRAFI 140N or EQUIVALENT
FLEXIBLE PLASTIC PIPE 1 1/2"-3/4" DRAIN ROCK
Notes:
1) Drain rock should contain no more than 5 percent fines passing the U.S. No. 200 Sieve. Date:7/18/2017
2)Trench bottom and drain pipe should be sloped to drain to approved discharge location. Drawn by: BLC
Project: 72nd Avenue Apartments
Tigard, Oregon Project No. 17-4532 FIGURE 5
CeoPácitic
Engineering,Inc.
Real-World Geotechnical Solutions
Investigation • Design • Construction Support
EXPLORATION LOGS
14835 SW 72nd Avenue Tel (503) 598-8445
Portland, Oregon 97224 Fax (503) 941-9281
14835 SW 72nd Avenue BORING LOG
GeoPacific Portland, Oregon 97224
Ia uu.Inktc Tel: (503)598-8445 Fax: (503)941-9281
Project: 72nd Avenue Apartments Project No. 17-4626 BoringNo. B-1
Tigard, Oregon
T CO '5 ii5N1
, o
o z a 0 o .@ Material Description
C,) U m
Topsoil. Grassy lawn surface. Organic Lean CLAY (OL-CL), brown with roots
extending to approximately 10 inches.
N 6 Lean CLAY(CL), brown and dark gray, with some angular gravel and with trace
charred organic material, medium stiff, moist, moderately plastic.
5-
8 92.3 28.2 AASHTO Soil Classification =A-7-6(24), Liquid Limit=46, Plasticity Index= 23
10 Infiltration test IT-1.1 conducted at-10 feet bgs.
10 Measured infiltration rate = 0 inches per hour.
ill
5 85.3 32.5
SILT(ML), brown, medium stiff, very moist becoming wet, low plasticty.
AASHTO Soil Classification =A-4(7), Liquid Limit= 34, Plasticity Index= 8
15
15-
6 92.3 34.6 j Groundwater encountered at-15 feet bgs.
AASHTO Soil Classification =A-4(0), Liquid Limit= 26, Plasticity Index= 0.3
20-
2 94.8 39.5 AASHTO Soil Classification =A-4(2), Liquid Limit = 28, Plasticity Index = 2
✓� Infiltration test IT-1.2 conducted at-20 feet bgs.
Measured infiltration rate = 0 inches per hour.
25—
6 99.0 33.7 AASHTO Soil Classification =A-4(9), Liquid Limit= 32, Plasticity Index= 8
30— 27 94.6 41.6
Elastic SILT (MH), light brown to blue gray, micaceous, stiff to very stiff, wet, high
plasticity.
AASHTO Soil Classification =A-7-5(34), Liquid Limit = 61, Plasticity Index = 28
35—
26
Fat CLAY(CH), blue gray, stiff to very stiff, wet, high plasticity.
40— AASHTO Soil Classification =A-7-5(64), Liquid Limit = 94, Plasticity Index= 62
25 89.0 41.2 4/ Boring terminated at 41.5 feet.
Groundwater encountered at 15 feet bgs.
LEGEND o Date Drilled: 07/03/17
,00 —
o- s / Logged By: BGA
g Surface Elevation: —239 ft
Static Water Table Sample Split-Spoon Shelby Tube Sample
at Drilling Static Water Table Water Bearing Zone
_41) `1t`, 14835 SW 72nd Avenue
GeoPacific Portland,Oregon 97224 BORING LOG
Ea01MN16g. , Tel: (503)598-8445 Fax: (503)941-9281
Project: 72nd Avenue Apartments Project No. 17-4626 Boring No.B-2
Tigard, Oregon
a)
C
, a)o o
> '3) o
.0 N - NN > C .. 0)
�° f0 N N �° = Material Description
°- 0 > aZtn 3-- P
o co
o z o 0 m
co
Asphalt Parking Lot. 3 Inches A/C, underlain by 6 inches of crushed aggregate.
Lean CLAY(CL), brown and dark gray, with some angular gravel and with trace
N12 charred organic material, medium stiff, moist, moderately plastic.
5 Infiltration test IT-2.1 conducted at-5 feet bgs.
8 Measured infiltration rate = 0 inches per hour.
6
10- N -
4 12.5 SILT (ML), brown, medium stiff, very moist becoming wet, low plasticity.
M
N 6 /// Infiltration test IT-2.2 conducted at-10 feet bgs.
____
Measured infiltration rate = 0 inches per hour.
15 I
N 4
N 3
20—
3 Infiltration test IT-2.3 conducted at-20 feet bgs.
Measured infiltration rate = 0 inches per hour.
25— Elastic SILT (MH), light brown to blue gray, micaceous, stiff to very stiff, wet, high
23 plasticity.
Boring terminated at 26.5 feet.
Groundwater encountered at 12.5 feet bgs.
30-
35-
40—
LEGEND - Date Drilled: 07/03/17
loo o-09 Logged By: BGA
1,000 g
—
Static Water Table Surface Elevation: -240 ft
Bag Sample Split-Spoon Shelby Tube Sample at Drilling Static Water Table Water Bearing Zone
\1 14835 SW 72nd Avenue
GeoPacific Portland,Oregon 97224 BORING LOG
euanann.ec. Tel: (503)598-8445 Fax: (503)941-9281
Project: 72nd Avenue Apartments Project No. 17-4626 BoringNo. B-3
Tigard, Oregon
CD
T a, co m? o
NI
t N N N > '.. t pl
�° °' " Material Description
o I- o� o.
p Cl) Z o Z o m
U
Topsoil. Grassy lawn surface. Organic Lean CLAY (OL-CL), brown with roots
extending to apuroximatejyj0 inches. _
111 Lean CLAY (CL), brown and dark gray, with some angular gravel and with trace
6 charred organic material, medium stiff, moist, moderately plastic.
5=
8
11
10- N _
10 SILT (ML), brown, medium stiff, very moist becoming wet, low plasticity.
_ N11 15
15—
N 6
[Shelby tube pushed at depth of 17.5 feet, easy to push sampler first
12 inches but stiffer for last 6 inches, full recovery]
20— 7
Elastic SILT (MH), light brown to blue gray, micaceous, medium stiff to very stiff,
wet, high plasticity.
25
id 7
30—
Id 7
35-
27
Fat CLAY (CH), blue gray, stiff, wet, high plasticity.
Y
40— —
11 / Boring terminated at 41.5 feet.
Groundwater encountered at 15 feet bgs.
LEGEND o Date Drilled: 07/03/17
111
M. 10-20-99 0% Logged By: BGA
)------,
100 to
1,000 g _
Static Water Table Surface Elevation: —237 ft
Bag Sample Split-Spoon Shelby Tube Sample at Drilling Static Water Table Water Bearing Zone
`r1/4._ 14835 SW 72nd Avenue
GeoPacific Portland,Oregon 97224 BORING LOG
Erianessatint. Tel: (503) 598-8445 Fax: (503)941-9281
Project: 72nd Avenue Apartments Project No. 17-4626 BoringNo. B-3
Tigard, Oregon
a)
N 0o �o o
a > a o o c Material Description
o z o z 2 0
to U m
Topsoil. Grassy lawn surface. Organic Lean CLAY (OL-CL), brown with roots
extending to approximately 10 inches. _
-
6 Lean CLAY (CL), brown and dark gray, with some angular gravel and with trace
charred organic material, medium stiff, moist, moderately plastic.
5- Liii 8
Aii
10- � _
10 SILT (ML), brown, medium stiff, very moist becoming wet, low plasticity.
- 11 15
15
N6
[Shelby tube pushed at depth of 17.5 feet, easy to push sampler first
—
12 inches but stiffer for last 6 inches, full recovery]
20— 7
Elastic SILT (MH), light brown to blue gray, micaceous, medium stiff to very stiff,
wet, high plasticity.
25-
Id 7
30-
- N 7
35-
- N
— Fat CLAY (CH), blue gray, stiff, wet, high plasticity.
40— -
11 A/ Boring terminated at 41.5 feet.
Groundwater encountered at 15 feet bgs.
LEGEND - Date Drilled: 07/03/17
100 to [114
M 10-20-95 Logged By: BGA
,.0009
— Surface Elevation: —237 ft
Static Water Table
BagSample Split-Spoon ShelbyTube Sample at Drilling
Static Water Table Water Bearing Zone
17120 / GeoPacific / CPT-1 / 11720 SW 72nd Tigard
TEST DATE:7/31/2017 8:51:52 AM CONE ID:DPG1323
HOLE NUMBER:CPT-1 LOCATION: 17120/GeoPacific/CPT-1 /11720 SW 72nd Tigard
JOB NUMBER: 17120/GeoPacific/CPT-1 /11720 SW 72nd Tigard
CUSTOMER: 17120/GeoPacific/CPT-1 /11720 SW 72nTEST DATE:7/31/2017 8:51:52 AM
OPERATOR:OGE bb TOTAL DEPTH:53.150 ft
SPT N60 Soil Behavior Type Tip Resistance(Qt) Sleeve Friction(Fs) F.Ratio Pore Pressure(U2)
(UNITLESS) (UNITLESS) (tsf) (tsf) (%) (psi)
0 0 120 0 12 0 300 0 5 0 7 -100 600
I I I I I I I I I I I I I I I I I I I I I I I I
20 - ��
Depth 30 — —
(ft)
c'
40 — — — —
60
TOTAL DEPTH:53.150 ft
.1 sensitive fine grained .4 silty clay to clay .7 silty sand to sandy silt 10 gravelly sand to sand
2 organic material .5 clayey silt to silty clay ,z 8 sand to silty sand 11 very stiff fine grained(')
3 clay .6 sandy silt to clayey silt w 9 sand 12 sand to clayey sand(*)
*SBT/SPT CORRELATION:UBC-1983
COMMENT: 17120/GeoPacific/CPT-1 / 11720 SW 72nd Tigard
Depth
Arrival 5.23mS
Reft .28 \ - ____ _ - Velocity*
Depth 6.56ft Arrival 10.27mS
Ref 3.28ft - Velocity 485.25ft/S
Depth 13.12ft
/,I Arrival 21.52mS
Ref 6.56ft -_ -_-_ Velocity 530.97ft/S
Depth 16.40ft Arrival 25.78mS
Ref 13.12ft t - _ - --- . Velocity 739.99ft/S
Depth 19.69ft I Arrival 31.48mS
Ref 16.40ft _,_--- -- /I Velocity 559.76ft/S
Depth 26.25ft Arrival 41.76mS
Ref 19.69ft _ -- -- Velocity 627.80ft/S
Depth 32.81ft Arrival 50.43mS
Ref 26.25ft __ Velocity 748.84ft/S
Depth 39.37ft Arrival 53.94mS
Ref 32.81ft - Velocity 1853.55ft/S
Depth 45.93ft Arrival 56.52mS
Ref 39.37ft - --,.-- Velocity 2532.59ft/S
Depth 52.49ft fl Arrival 60.70mS
Ref 45.93ft Velocity 1564.11ft/S
0 10 20 30 40 50 60 70 80 90 100
Time(mS)
Hammer to Rod String Distance(ft):4.27
=Not Determined
17120 / GeoPacific / CPT-1 / 11720 SW 72nd Tigard
TEST DATE:7/31/2017 8:51:52 AM CONE ID:DPG1323
HOLE NUMBER:CPT-1 LOCATION: 17120/GeoPacific/CPT-1 /11720 SW 72nd Tigard
JOB NUMBER: 17120/GeoPacific/CPT-1 /11720 SW 72nd Tigard
CUSTOMER: 17120/GeoPacific/CPT-1 /11720 SW 72nTEST DATE:7/31/2017 8:51:52 AM
OPERATOR:OGE bb TOTAL DEPTH:53.150 ft
SPT N60 Soil Behavior Type Seismic Velocity Tip Resistance(Qt)
(UNITLESS) (UNITLESS) (ft/s) (tsf)
0 0 120 0 12 0 3000 0 300
I I II I I I I 1\ I I I 1
485
531
10 —
740
560
20 — - — 628 —
749
Depth 30 — — —
(ft)
1854
40 — —
2533
1564
50 '
60 --
TOTAL DEPTH:53.150 ft
▪1 sensitive fine grained U 4 silty clay to clay 7 silty sand to sandy silt 10 gravelly sand to sand
®2 organic material •5 clayey silt to silty clay 8 sand to silty sand 11 very stiff fine grained(*)
•3 clay !6 sandy silt to clayey silt 9 sand ' 12 sand to clayey sand(*)
*SBT/SPT CORRELATION:UBC-1983
COMMENT: 17120 / GeoPacific / CPT-1 / 11720 SW 72nd Tigard
3T DATE:
ERATOR:OGE bb
6
DEPTH(ft)
24.934
5-
4
(1
PRESSURE
(PSI)
3
2
1
0 5 10 15 20 25 30
MAXIMUM PRESSURE=5.437(PSI) TIME:(MINUTES)
HYDROSTATIC PRESSURE=5.389(PSI),WATER TABLE: 12.50 ft
Georacitic
Engineering,Inc.
Real-World Geotechnical Solutions
Investigation • Design • Construction Support
LABORATORY TEST RESULTS
14835 SW 72nd Avenue Tel (503) 598-8445
Portland, Oregon 97224 Fax (503) 941-9281
Particle Size Distribution Report
000
C C C C G V � N 2 7 S 0 V N
100 .. 0 N ,- N- 6 a `U C U . -- •
0
90 10
80
20
70 30
CC m
L 73
Z_ 60 40 m
Li Z
I—Z 50 - 50 H
L 0
0 O
0_ 40 - 60
L
Cr)
30 m
i 70 73
20 , � 80
10 - _ - 90
0 1 I 100
100 10 1 0.1 0.01 0.001
GRAIN SIZE - mm.
0 +3„ %Gravel %Sand %Fines _
Coarse Fine Coarse Medium Fine Silt Clay
0.0 0.0 0.0 0.1 1.3 6.3 92.3
TEST RESULTS Material Description
Opening I Percent Spec.* Pass? Lean Clay
Size Finer (Percent) (X=Fail)
.75 100.0
.5 100.0 Atterberg Limits(ASTM D 4318)
.375 100.0 PL= 23.4 LL= 46.8 PI= 23.4
.25 100.0
#4 100.0 Classification
#10 99.9 USCS(D 2487)= CL AASHTO(M 145)= A-7-6(24)
#20 99.4 Coefficients
#40 98.6 Dg0= D85=
#100 96.8 D50= D30= D15=
#200 92.3 D10= Cu= Cc=
Remarks
Moisture 28.2%
Date Received: Date Tested: 7/10/2017
Tested By: SJC
Checked By:
Title:
(no specification provided)
Location:B-1 Date Sampled: 7/3/2017 BLC
Sample Number: S17-200 Depth: 5'
G E O PA C I F I C Client: Hill Architects
Project: 72nd.Avenue Apartments
ENGINEERING, INC. Project No: 17-4626 Figure
LIQUID AND PLASTIC LIMITS TEST REPORT
60 Dashed line indicates the approximate
upper limit boundary for natural soils
50
G�otO�
x 40 --
w
0
z
U 30
H
Q •
a 20-- gip\- -
G�0 1
•
lo— A
____ / z 4,-L.7 z ML or OL MH or OH
0 0 10 20 30 40 50 60 70 80 90 100 110
LIQUID LIMIT
48.6 1I '
48.2--
47.8
47.4
1-
Z
H 47
z
0 46.6
ccLu
46.2
45.8
45.4
45
—44k-
5 6 7 8 9 1Q 20 25 30 40
NUMBER OF BLOWS
MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS
• Lean Clay 46.8 23.4 23.4 98.6 92.3 CL
Project No. 17-4626 Client: Hill Architects Remarks:
Project: 72nd.Avenue Apartments
Location: B-1
Sample Number: S17-200 Depth: 5'
GEOPACIFIC ENGINEERING, INC. 1� Figure
Tested By: SJC
Particle Size Distribution Report
• . c,
e _ s00 0 0 0 0 0 0 7
.- % % ik it it It
N M 7 W N
fD M N ,- \ ik
100 o a � o 0
90
10
80 20
70 I- 30
fl
m
Lu 73
Z_ 60 40 m
LT_ Z
Z 50 50 -
Lu n
0 2>
0' 40 60 ;Cl
w CD
0_ m
30- 70 73
20 i i I i 80
1 i i i i i i
10 I i 90
1 i i I i
I i i i i
0
100
100 10 1 0.1 0.01 0.001
GRAIN SIZE - mm.
%+3„ %Gravel %Sand %Fines
Coarse Fine Coarse Medium _ Fine Silt _ Clay
0.0 0.0 0.0 0.2 4.0 10.5 85.3
TEST RESULTS Material Description
Opening Percent Spec.* Pass? Silt with Sand
Size Finer (Percent) (X=Fail)
.75 100.0
.5 100.0 Atterberg Limits(ASTM D 4318)
.375 100.0 PL= 26.4 LL= 34.5 PI= 8.1
.25 100.0
#4 100.0 Classification
#10 99.8 USCS(D 2487)= ML AASHTO(M 145)= A-4(7)
#20 97.4 Coefficients
#40 95.8 D90= 0.1037 D85= 060=
#100 94.0 D50= D30= D15=
#200 85.3 D10= Cu= Cc=
Remarks
Moisture 32.5%
Date Received: Date Tested: 7/10/2017
Tested By: SJC
Checked By:
Title:
(no specification provided)
Location: B-1 Date Sampled: 7/3/2017 BLC
Sample Number: S17-201 Depth: 10'
G E O PACIFIC Client: Hill Architects
Project: 72nd.Avenue Apartments
ENGINEERING, INC. Project No: 17-4626 Figure
LIQUID AND PLASTIC LIMITS TEST REPORT
60
Dashed line indicates the approximate
upper limit boundary for natural soils r'
50
Ga o•
X 40
w
0
Z
U 30--
F
a
a 20— tOv
77 Geo
77
10—
/�/// ML������Z • ML or OL MH or OH
0
0 10 20 30 40 50 60 70 80 90 100 110
LIQUID LIMIT
36.8
36.4
36
35.6
1–
z
35.2
z
0U 34.8
cc
Lu
Q 34.4
34
33.6
33.2
32.8
5 6 7 8 9 10 20 Z5 30 -40
NUMBER OF BLOWS
MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS
• Silt with Sand 34.5 26.4 8.1 95.8 85.3 ML
Project No. 17-4626 Client: Hill Architects Remarks:
Project: 72nd.Avenue Apartments
Location:B-1
Sample Number: S17-201 Depth: 10'
GEOPACIFIC ENGINEERINGINC.
,
_ Figure
Tested By: SJC
Particle Size Distribution Report
000
C C C C C . 0 0 0 O 0 0 V 0
t0 t'7 N '- \ \ 8- ? N C) tD N
100C 0
90 I 10
1
1
80 20
70 - 30
CC
m
w 3D
z 60 40 n
ti
m
i— z
H
z 50 50 (7
tii
0 O
CL 40 60 X
0_10
30 m
70 3D
20 80
10 90
0 100
100 10 1 0.1 0.01 0.001
GRAIN SIZE-mm.
%+3„ %Gravel %Sand %Fines
Coarse Fine Coarse Medium Fine Silt Clay
0.0 0.0 0.0 0.0 0.2 7.5 92.3
TEST RESULTS Material Description
Opening Percent Spec.* Pass? Silt
Size Finer (Percent) (X=Fail)
.75 100.0
.5 100.0 Atterberg Limits(ASTM D 4318)
.375 100.0 PL= 25.9 LL= 26.2 Pl= 0.3
.25 100.0
#4 100.0 Classification
#10 100.0 USCS(D 2487)= ML AASHTO(M 145)= A-4(0)
#20 100.0 Coefficients
#40 99.8 090= D85= D60=
#100 99.2
#200 92.3 D10= Cu0_ D15=
Remarks
Moisture 34.6%
Date Received: Date Tested: 7/10/2017
Tested By: SJC
Checked By:
Title:
*
(no specification provided)
Location: B-1 Date Sampled: 7/3/2017 BLC
Sample Number: S17-202 Depth: 15' ___
GEOPACIFIC CIFIC Client: Hill Architects
/`1 Project: 72nd.Avenue Apartments
ENGINEERING, INC. Project No: 17-4626 Figure
LIQUID AND PLASTIC LIMITS TEST REPORT
60 Dashed line indicates the approximate
upper limit boundary for natural soils
50—
,0‘\
x40—
w
a
30--
E E
cn
.20 ._... ,� VoCO.
G
10—
Z ML it OL MH or OH
0 0 10 20 30 40 50 60 70 80 90 100 110
LIQUID LIMIT
27.2
27
26.8
26.6
26.4
o 26.2
Lu
I- 26
25.8
25.6
25.4
25.2
5 6 7 8 9 10 20 25 30 40
NUMBER OF BLOWS
MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS
• Silt 26.2 25.9 0.3 99.8 92.3 ML
Project No. 17-4626 Client: Hill Architects Remarks:
Project: 72nd.Avenue Apartments
Location: B-1
Sample Number: S17-202 Depth: 15'
GEOPACIFIC ENGINEERING, INC.
Figure
Tested By: SJC
Particle Size Distribution Report
000
C C C C .c s j7� o ]o M o so N
N r r
100 f0 CO Y C l.j` 4 0
90 - - 1 10
1
1
I
80 y. 1 1 i i 1 20
1 1 1 1 1 1 1 1 1 1 1 1 1
I 1 1 I I I I 1 1 1 I 1 1
1 1 I ii i [ 1 1 I 1 I 1
70 I I I I I
30 -0
CC X
m
Lu
Z_ 60- 40 m
u_ z
I— H
Z 50 50 0
Lu O
0
0_ 40 60 ,-tXj
Lu W
0_
M
30
70 X
20 , 7 1 - 80
10 90
0 100
100 10 1 0.1 0.01 0.001
GRAIN SIZE -mm.
%+3„ %Gravel %Sand %Fines
Coarse Fine Coarse Medium Fine Silt Clay
0.0 0.0 0.0 0.0 0.1 5.1 94.8
TEST RESULTS Material Description
Opening Percent Spec.* Pass? Silt
Size Finer (Percent) 1 (X=Fail)
.75 100.0
.5 100.0 Atterberg Limits(ASTM D 4318)
.375 100.0 PL= 26.2 LL= 28.1 P1= 1.9
.25 100.0
#4 100.0 Classification
#10 100.0 USCS(D 2487)= ML AASHTO(M 145)= A-4(2)
#20 99.9
#40 99.9 Coefficients
#100 99.5 D50= D30= D15=
#200 94.8 D10= Cu= Cc=
Remarks
Moisture 39.5%
Date Received: Date Tested: 7/10/2017
Tested By: SJC
Checked By:
Title:
(no specification provided)
Location: B-1 Date Sampled: 7/3/2017 BLC
Sample Number: S17-203 Depth: 20'
G E O PACIFIC Client: Hill Architects
Project: 72nd.Avenue Apartments
ENGINEERING, INC. Project No: 174626 Figure
LIQUID AND PLASTIC LIMITS TEST REPORT
60
Dashed line indicates the approximate
upper limit boundary for natural soils
50—
Ca o�0�
X 40
w
0
U 30
a20 oc
C"-
10—
/ Z ML or OL MH or OH
•
0 10 20 30 40 50 60 70 80 90 100 110
LIQUID LIMIT
28.9
28.7
28.5
28.3
z
LU 28.1
z
o 27.9
~27.7
27.5
27.3
27.1
26.9
5 6 7 8 _9- 10 20 25 30 - 40
NUMBER OF BLOWS
MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS
• Silt 28.1 26.2 1.9 99.9 94.8 ML
Project No. 17-4626 Client: Hill Architects Remarks:
Project: 72nd.Avenue Apartments
Location: B-1
Sample Number: S17-203 Depth: 20'
GEOPACIFIC ENGINEERING, INC.
Figure
Tested By: SJC
Particle Size Distribution Report
_ 0
10 00
.5 .5 5 .5 ., C< coo Q N op,') c, t�0 8
0 t0 "' N - 6 Y V C }V #
# # # I O
90 10
80 i i i i 1 i 1 i i i 1 20
70 30 TI
rn
CC 73w
Z 60 40 m
m
( Z
Z 50 50 n
Lu 0
o y
X 40 60 73
Lu Cn
w m
30 -70 :0
20 1 , 1 , , 80
10 - 90
0 100
100 10 1 0.1 0.01 0.001
GRAIN SIZE- mm.
%+3„ %Gravel %Sand %Fines
Coarse Fine Coarse Medium Fine Silt Clay
0.0 0.0 0.0 0.1 0.0 0.9 99.0
TEST RESULTS Material Description
Opening Percent Spec.* Pass? Silt
Size Finer (Percent) (X=Fail)
.75 100.0
.5 100.0 Atterberg Limits(ASTM D 4318)
.375 100.0 PL= 24.5 LL= 32.5 PI= 8.0
.25 100.0 I
#4 100.0 Classification
#10 99.9 USCS(D 2487)= ML AASHTO(M 145)= A-4(9)
#20 99.9 Coefficients
#40 99.9 D90= D85= D60=
#100 99.8 D50= D30= D15=
#200 99.0 D10= Cu= Cc=
Remarks
Moisture 33.7%
Date Received: Date Tested: 7/10/2017
Tested By: SJC
Checked By:
Title:
(no specification provided)
Location:B-1 Date Sampled: 7/3/2017 BLC
Sample Number: S17-204 Depth: 25'
GE O PACIFIC Client: Hill Architects
Project: 72nd.Avenue Apartments
ENGINEERING, INC. Project No: 17-4626 Figure
LIQUID AND PLASTIC LIMITS TEST REPORT
60
Dashed line indicates the approximate
upper limit boundary for natural soils
50 _
G�of 0�
x 40
Lu
0
z
U 30—
i=
EL 20— oc Ov
G7. ••
10— A
��� ML or OL MH or OH
0 1
0 10 20 30 40 50 60 70 80 90 100 110
LIQUID LIMIT
34.6
34.2
33.8—
33.4 IN .
r
z
H 33
z
O
U 32.6
cCLu
Q32.2
31.8
31.4
31
30.6 1 1
5 6 7 8 9 10- - 20 25 30 40
NUMBER OF BLOWS
MATERIAL DESCRIPTION LL PL PI %<#4O 1 %<#200 USCS
• Silt 32.5 24.5 8.0 99.9 99.0 ML
Project No. 17-4626 Client: Hill Architects Remarks:
Project: 72nd.Avenue Apartments
Location: B-1
Sample Number: S17-204 Depth: 25'
GEOPACIFIC ENGINEERING, INC. i Figure
Tested By: SJC
Particle Size Distribution Report
< < coV onto
<_ � o O O O O
/� N N C) [r �D N
100 tD t+) N - C x C yl I
�t_ # # ik # #
V v j 0
1
I
90 i 10
1
1
80 I
20
I 1
I 1 1 1 I
I I I I I I I
1 I 1
70 - 30
C m
LU
X
Z 60 —40 m
m
I— Z
H
Z 50 11 I I I I I I I I I I - 50 a
Lu I 1 1 1 1 1 1 I 1 1 1 1 n
1 1 1 1 1 I 1 I 1 1 I o
0N I I I 11 I i 1 I I I DT
LL 40 I 1 I I I I 11 60 N
w /^
LL m
30 m
70 3:1
20 1 1 7 1 1 1 1 11 80
10 90
0 100
100 10 1 0.1 0.01 0.001
GRAIN SIZE- mm.
%+3„ %Gravel %Sand %Fines
Coarse Fine Coarse Medium Fine Silt Clay
0.0 0.0 0.0 0.0 0.0 5.4 94.6
TEST RESULTS Material Description
Opening Percent Spec.* Pass? Elastic Silt
Size Finer (Percent) (X=Fail)
.75 100.0
.5 100.0 Atterberg Limits(ASTM D 4318)
.375 100.0 PL= 32.4 LL= 61.0 PI= 28.6
.25 100.0
#4 100.0 Classification
#10 100.0 USCS(D 2487)= MH AASHTO(M 145)= A-7-5(34)
#20 100.0 Coefficients
#40 100.0 D90= 085= D60=
#100 99.2
#200 94.6 010=CuU_Ccc
s=
Remarks
Moisture 41.6%
Date Received: Date Tested: 7/10/2017
Tested By: SJC
Checked By:
Title:
(no specification provided)
Location: B-1 Date Sampled: 7/3/2017 BLC
Sample Number: S17-205 Depth: 30'
G E O PACIFIC Client: Hill Architects
Project: 72nd.Avenue Apartments
ENGINEERING, INC. Project No: 17-4626 Figure
LIQUID AND PLASTIC LIMITS TEST REPORT
60
Dashed line indicates the approximate
upper limit boundary for natural soils
50—
GY`
x 40--
w
z
- 30—
f=
a 20
G'-
10—
�c ML�� / ML or OL MH or OH
0 0 10 20 30 40 50 60 70 80 90 100 110
LIQUID LIMIT
66
65
64
63 •
z
F 62
z
o
O 61
H 60
59
58
57
56 -
5 6 7 8 9 W 20 25 30 40
NUMBER OF BLOWS
MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS
• Elastic Silt 61.0 32.4 28.6 100.0 94.6 MH
Project No. 17-4626 Client: Hill Architects Remarks:
Project: 72nd.Avenue Apartments
Location:B-1
Sample Number: S17-205 Depth: 30'
GEOPACIFIC ENGINEERING, INC.
Figure
Tested By: SJC
Particle Size Distribution Report
_ 000
< � 0 00 0 ' 0
100 tO a> N - '- CI a Cir C c,- / w 0u . 4t u0is
0
I
90 10
1
80 20
70 30 m
fY 7Jw
Z 60 40 m
ii H
I-
50 50 (')
W 0
0_• 40 60 33
w (/)
0_ m
30- 70 33
20 7 , 1 I I 80
I i i i i i
I i i i i i
I i i i i I
10 i II i i i i i 90
I i i i i I i
i i i i I i
0 � 1 100
100 10 1 0.1 0.01 0.001
GRAIN SIZE -mm.
%+3" %Gravel %Sand %Fines
Coarse Fine Coarse Medium Fine Silt Clay
0.0 0.0 0.0 0.0 1.0 10.0 89.0
TEST RESULTS Material Description
Opening Percent Spec.* Pass? Fat Clay
Size Finer (Percent) (X=Fail)
.75 100.0
.5 100.0 Atterberg Limits(ASTM D 4318)
.375 100.0 PL= 31.7 LL= 94.4 PI= 62.7
.25 100.0
#4 100.0 Classification
#10 100.0 USCS(D 2487)= CH AASHTO(M 145)= A-7-5(64)
#20 99.7 Coefficients
#40 99.0 D90= 0.0806 D85= 060=
#100 97.2 D50= D30= 015=
#200 89.0 D10= Cu— Cc=
Remarks
Moisture 41.2%
Date Received: Date Tested: 7/10/2017
Tested By: SJC
Checked By:
Title:
(no specification provided)
Location: B-1 Date Sampled: 7/3/2017 BLC
Sample Number: S17-206 Depth:40'
G E O PACIFIC Client: Hill Architects
Project: 72nd.Avenue Apartments
ENGINEERING, INC. Project No: 17-4626 Faure
LIQUID AND PLASTIC LIMITS TEST REPORT
120
100
Dashed line indicates the approximate
x ao— upper limit boundary for natural soils
z --
so •
cn GN of ON
Q 'a 40—
20— - GL oc 01
OML or OL MH or OH
0 10 20 30 40 50 60 70 80 90 100 110
LIQUID LIMIT
100
99
98
97
F• 96
O• 95
w
94
93
92
91
90
5 6 7 8 9 14 20 -25 30 40
NUMBER OF BLOWS
MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS
• Fat Clay 94.4 31.7 62.7 99.0 89.0 CH
Project No. 17-4626 Client: Hill Architects Remarks:
Project: 72nd.Avenue Apartments
Location: B-1
Sample Number: S17-206 Depth:40'
GEOPACIFIC ENGINEERING, INC.
Figure
Tested By: SJC
CeoPaultiC
Engineering,Inc.
Real-World Geotechnical Solutions
Investigation • Design • Construction Support
LIQUEFACTION ASSESSMENT
14835 SW 72nd Avenue Tel (503) 598-8445
Portland, Oregon 97224 Fax(503) 941-9281
::Vertical&Lateral displ.acements estimation for saturated sands::
Depth (N1)6o.: )(km Fa FSiiq Ymax ev dz Sv-1D LDI
(ft) (%) (ob) (%) (ft) (in) (ft)
15.00 12 38.03 0.86 0.458 38.03 3.34 5.00 2.005 1.90
20.00 8 59.22 0.94 0.313 59.22 4.23 5.00 2.536 2.96
25.00 11 42.40 0.89 0.338 42.40 3.53 5.00 2.118 2.12
30.00 32 3.50 -0.22 2.000 0.00 0.00 5.00 0.000 0.00
35.00 30 4.65 -0.09 1.067 3.07 0.61 5.00 0.367 0.15
40.00 28 6.08 0.04 0.821 5.07 1.08 5.00 0.648 0.25
Cumulative settlements: 7.673 7.39
Abbreviations
y,;m: Limiting shear strain(%)
Fa/N: Maximun shear strain factor
ymax: Maximum shear strain(%)
ev:: Post liquefaction volumetric strain (%)
Sv.io: Estimated vertical settlement(in)
LDI: Estimated lateral displacement(ft)
incur- n 1 cn CDT 4.v.-I; iof-,.•firs.,nceoe.e..,or,r c.,f+,,i,. Paae: 3
• Ronald D. Andrus, Hossein Hayati, Nisha P. Mohanan, 2009. Correcting Liquefaction Resistance for Aged Sands Using Measured
to Estimated Velocity Ratio, Journal of Geotechnical and Geoenvironmental Engineering,Vol. 135, No. 6, June 1
• Boulanger, R.W. and Idriss, I. M., 2014. CPT AND SPT BASED LIQUEFACTION TRIGGERING PROCEDURES. DEPARTMENT OF
CIVIL&ENVIRONMENTAL ENGINEERING COLLEGE OF ENGINEERING UNIVERSITY OF CALIFORNIA AT DAVIS
• Robertson, P.K. and Cabal, K.L., 2007, Guide to Cone Penetration Testing for Geotechnical Engineering. Available at no cost at
http://www.geologismiki.gr/
• Youd, T.L., Idriss, I.M., Andrus, R.D., Arango, I., Castro, G., Christian, J.T., Dobry, R., Finn, W.D.L., Harder, L.F., Hynes, M.E.,
Ishihara, K., Koester, J., Liao, S., Marcuson III, W.F., Martin, G.R., Mitchell, J.K., Moriwaki, Y., Power, M.S., Robertson, P.K.,
Seed, R., and Stokoe, K.H., Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF
Workshop on Evaluation of Liquefaction Resistance of Soils, ASCE, Journal of Geotechnical & Geoenvironmental Engineering,
Vol. 127, October, pp 817-833
• Zhang, G., Robertson. P.K., Brachman, R., 2002, Estimating Liquefaction Induced Ground Settlements from the CPT, Canadian
Geotechnical Journal, 39: pp 1168-1180
• Zhang, G., Robertson. P.K., Brachman, R., 2004, Estimating Liquefaction Induced Lateral Displacements using the SPT and CPT,
ASCE, Journal of Geotechnical &Geoenvironmental Engineering, Vol. 130, No. 8, 861-871
• Pradel, D., 1998, Procedure to Evaluate Earthquake-Induced Settlements in Dry Sandy Soils, ASCE, Journal of Geotechnical &
Geoenvironmental Engineering,Vol. 124, No. 4, 364-368
• R. Kayen, R. E. S. Moss, E. M. Thompson, R. B. Seed, K. 0. Cetin, A. Der Kiureghian,Y.Tanaka, K. Tokimatsu, 2013. Shear-
Wave Velocity—Based Probabilistic and Deterministic Assessment of Seismic Soil Liquefaction Potential,Journal of Geotechnical
and Geoenvironmental Engineering, Vol. 139, No. 3, March 1
TABLE OF CONTENTS
17120 CPT-1 Text File results
Summary data report 1
Vertical settlements summary report 8
Lateral displacements summary report 9
CLiq v.2.2.0.32-CPT Liquefaction Assessment Software-Report created on: 8/20/2018, 3:54:56 PM
Procedure for the evaluation of soil liquefaction resistance, NCEER(1998)
Calculation of soil resistance against liquefaction is performed according to the Robertson & Wride (1998) procedure. The
procedure used in the software, slightly differs from the one originally published in NCEER-97-0022 (Proceedings of the NCEER
Workshop on Evaluation of Liquefaction Resistance of Soils). The revised procedure is presented below in the form of a
flowchart':
r
qk : tip resistance.f, sleeve friction
cs1,n ' ; in-situ vertical total and effective stress
units : all in kPa
initial stress exponent" : n= 11)and calculate Q, F.and 14
if1, 1.64,n=0.5
if 1.61 < I < 3.30,n= (l 1.64)0.3 +0.5
ifl,> 3.30, n= 10
iterate until the chane:in it, An<0.01
if ay,'>3(H)kPa,let n= 1.0('or all soils
`'updated from
Robertson and 1(X}
Wridc (1998) Cr,
. 1,? ?
T
(q -G.�,) j. _ I.F 100100 F' (qc-47,,F,)
I, = 3.117-log ) -(1.22+log F),
if I < I.64, lc= 1.0
if 1.64 <lc<2.60. K�=-0.103 1,4+5.581 1,'-21.63 Ica+ 33.75 l;.- 17.88
if Io>2.60.evaluate using other criteria: likely nonliquefiahle if F> 1%
BUT. if 1.64<1,<2.36and F<0.5%, set K,, = 1.0
(41ciN)cs- K4.Q
CRR7.1-93• (.gk.t'v)ar -0.08, if 50 (cl4iN)is < 160
i 000
CRR„- 0.833. U q�l.�`)(. - 0.05, if(;11,1.4. 1., < 50
1000
if i > 2.60, evaluate using other criteria; likely nonliquifiable if F> 1%
1 "Esti rrati ng liquefaction-induced ground settlements from CPT for level ground", G. Zhang, P.K. Robertson, and R.W.I. Brachrran
Procedure for the evaluation of soil liquefaction resistance (all soils), Robertson (2010)
Calculation of soil resistance against liquefaction is performed according to the Robertson & Wride (1998) procedure. This
procedure used in the software, slightly differs from the one originally published in NCEER-97-0022 (Proceedings of the NCEER
Workshop on Evaluation of Liquefaction Resistance of Soils). The revised procedure is presented below in the form of a
flowchart':
CPT
qt,fs, ova,a'ti0.pa= 1 atm
all same units as pa
*
Initial stress exponent: n — LO;Calculate Q .F. IC
n=0.381(I;.)+0.051'„ 1-0.15
P,,
n 1.0
Iterate until change in n. An 0.01
- !
C, - \ PL
(7
$
[(cif —cr„ j
/,C. = •(-v. F. — )•10(
P, (q. —o-,..,
I; =1(3.47—log(2,,;y +0.22+1ogF,Yr`
1
I, 2.50 2.50 < I,< 2.70 1,> 2.70
v
IfI 1.64, Ic - 1.0 •
\Vhen 1.64< Ic 2.60
h,- 5.581c'-0.4031,4 -21.63I! t 33.751,- 17.88) K, =6x10--V,r6.74
If1.64 <1{ {:2.36AND FrK0.5%,set K,= 1.0
T
Qui.cs—he•Qui 4
V
�.,... 3
ERR,, =93 """ +0,08
1000 CR.R,, =0.053 .,,x„ i
50<_U,,,„ <160
1 P.K. Robertson, 2009. "Performance based earthquake design using the CPT', Keynote Lecture, International Conference on
Performance-based Design in Earthquake Geotechnical Engineering—from case history to practice,IS-Tokyo,June 2009
Procedure for the evaluation of soil liquefaction resistance, Idriss &Boulanger(2008)
_ qo: tip resistance, fs: sleeve friction
o„o, ovo': in situ vertical total and effective stress
m = 1.338 - 0.249 x(gc1N)°•264
iterate until change in m, dm < 0.01
A
•
P \m
CN = {1.7
IP" gc1N = CN X qc
Pa
7 �
< 2.60 > 2.60
V
gc1Ncs —Qc1N +L1gc1NCRR =0.80 X Su X Ka
Where : M=7.5,a a=1
avn
1.63+
9.7 / 15.7 Ail
A5.4+ X16/x e Fc+o.ol ,Fc+o.ol,
�Ic1N =
7
+,kiiva3lz9cin \i+ 9cin�s\43
540 , 67 (_ 80 , (. 114
=e`
CRR r�7.5,Qvo=1
Procedure for the evaluation of soil liquefaction resistance (sandy soils), Moss et al. (2006)
CPT
qt, fs, It
I< < Ic cut-off
Initial estimate using raw tip measurements, friction
ratio. Calculate qt,1. Repeat until an acceptable
convergence tolerance is achieved.
R f2
c = fi .
3
A
liC
P
Cg =
j ,
Iv
T
qt,1 =Cq qt
1
81,045 +g •(0.110 R )+ (7,001•R )+c (�+0.850 R )-0.848 In )-0.002•In(a )-20.923 +1.632. 1 J
CRR =exp t,1 t,1 f f f w v L
7,177
Procedure for the evaluation of soil liquefaction resistance, Boulanger&Idriss(2014)
CRR•u=7s,,:=ten.,
FSS _
),[ CSRx= =,r=,
/ 1 r ( 2f 3 4 \,
CSRm=7.5.,..4,,, 0.65 6ti. r 1 1 CRR -ex q`is`. +1 q`.,•c. -) tiCIN" + gsikl -2.80
tt='.5,c; am- a'. g d MSF KQ ''i '',`;_�`"'- p 113 ,„1000) t. 140 ) 137 �J
I I
r 1 t 1
rd=exp[a(z)+f3(z)•31] gLuNu=4,Lv+&gay
9.7 ' 15.7 2
) )
a z =-1.012-1.126sin z +5.133 CL,= 11.9+g`�:v exp 1.63-
0 ‘,.11.73 14.6) FC 1,,FC+2
)
f3(z)=0.106+0.118sin z +5.142
11.28 a q�Lv=C�=P
I
r \ V C- — PQ 51.7
K, =1-C,In - 151.1 t —
' PQ m=1.338-0.249(ga, )nava with 0.2645 m50.782
1 <0.3 /
Ce 37.3-827(qeL�s)a` — /*-------- r FC=80(Ic+CFC)-137 with 0%5_FC 5100%
4 JJJ
f Ml 1 ./, =[(3.47-1og(Q))`+(1.22+1og(F))a
MSF=1+(MSF„.—1)(8.64 exp(—i-1.325
� J
i K
MSF =1.09+�4.8t") 5 2.2 Q \g`POC I(6� with 0.5 5 n5.1.0 per Robertson&Wride(1998)
l J J1
d, and o;,at start of earthquake shaking F= f,6 1100%
`q; -
1
1 )d, at time of CPT sounding
_iq v.2.2.0.32-CPT Liquefaction Assessment Software 14
Procedure for the evaluation of liquefaction-induced lateral spreading displacements
Site investigation Design Ground
with SPT or earthquake geometry
i 1 f 1 1
SPT data with Moment magnitude Geometric parameters
content of earthquake(Mw) for each of different
or CPT data and peak surface zones in level(or
I acceleration(amax) gently sloping)ground
J with(or without)a free
face
v
/
.4077 \
Liquefaction potential analysis
to calculate FS,(Ni)6ocs or
(gcri)cs Zones with three major Zones with
— geometric parameters or more than
(using the NCEER SPT- less-free face height(H), three major
CPT-based method(Youd et al. the distance to a free face geometric
2001)) (L),or/and slope(S) parameters
r 1 r
Calculation of the lateral
displacement index L/H
Or/and Evaluation of
(using Figure 1 and Equation[3]) S lateral
displacements
based on
other
If 1 Estimated lateral displacement,LD approaches
(Ni)6ocs<14 For gently sloping ground without a free face, and
or engineering
(gcnc)cs<70 LD=(S+0.20) •LDI (for 0.2%<S<3.5%) judgment
For level ground with a free face,
evaluate
potential LD=6 •(L/III°s •LDI (for 5<L/H<40)
of
flow
liquefaction
\ 2
1 FI ow chart i l l ustrati ng major steps in estimating l i quefacti on-induced lateral spreading displacements using the proposed approach
a0 =4Ua
.....1 `z>itax
50
L LDI= 'Y axd:
ro 1 J.
40 -
in /I - 1 Equation [3]
ea
t 0 -.
or
E20 F ,o 1 \
E k 80°r,
0.0 0.5 1.0 1.5 2.0
Factor of safety. FS
1 Figure 1
1 "Estimating liquefaction-induced ground settlements from CPT for level ground", G. Zhang, P.K. Robertson, and R.W.I. Brachman
Procedure for the estimation of seismic induced settlements in dry sands
Average shear stress, Te,
=CSR • •600' =0.65 • •6IIo •tia
g
V
Estimate small shear strain modulus, Cij
Go =0.0188 [10(055I-158)].(gt - 6q)
Estimate shear strain amplitude, y
(based on Pradel (1998))
Y= 1 + a e x •R•100 (o)
1 + a
ti
R = G (Note ti. enciG 0 same units)
0
a =0.0389 6II +0.124
Pa
b =6400 Q6
Pa
Estimate volumetric strain in 15 cycles
-120
(N1)60cs
Euo](15)- L 20
Qtn.cs
(N1)60cs =
8.5 . 1 — 1c
[ 4.6
V
Vohune --stain in design earthquake
J10.45
uo1 -cuol(15) c15
Nc = (11/1 -4)2.17
Seismic settlement, s
G PIT
s = 2' uol'dz
Robertson, P.K.and Lisheng,S., 2010,"Estimation of seismic compression in dry soils using the CPT"FIFTH INTERNATIONAL CONFERENCE ON
RECENT ADVANCES IN GEOTECHNICAL EARTHQUAKE ENGINEERING AND SOIL DYNAMICS, Symposium in honor of professor I. M. Idriss,San
Diego,CA
Liquefaction Potential Index(LPI) calculation procedure
Calculation of the Liquefaction Potential Index (LPI) is used to interpret the liquefaction assessment calculations in terms of
severity over depth.The calculation procedure is based on the methology developed by Iwasaki (1982)and is adopted by AFPS.
To estimate the severity of liquefaction extent at a given site, LPI is calculated based on the following equation:
20
LPI = � (10 -0,5z)x F xdg
where:
FL= 1 - F.S. when F.S. less than 1
FL= 0 when F.S. greater than 1
z depth of measurment in meters
Values of LPI range between zero(0) when no test point is characterized as liquefiable and 100 when all points are characterized
as susceptible to liquefaction. Iwasaki proposed four(4)discrete categories based on the numeric value of LPI:
• LPI = 0 : Liquefaction risk is very low
•0 < LPI <= 5 : Liquefaction risk is low
• 5 < LPI <= 15 : Liquefaction risk is high
•LPI > 15 : Liquefaction risk is very high
0.0 1.0 2.0 0 ��z) 10
0
j
•
Ni 10 _ 10 _+81
...
0
15 • 15
20 •ti
20
Graphical presentation of the LPI calculation procedure
References
• Lunne, T., Robertson, P.K., and Powell, J.J.M 1997. Cone penetration testing in geotechnical practice, E & FN Spon Routledge,
352 p, ISBN 0-7514-0393-8.
• Boulanger, R.W. and Idriss, I. M., 2007. Evaluation of Cyclic Softening in Silts and Clays. ASCE Journal of Geotechnical and
Geoenvironmental Engineering June, Vol. 133, No. 6 pp 641-652
• Boulanger, R.W. and Idriss, I. M., 2014. CPT AND SPT BASED LIQUEFACTION TRIGGERING PROCEDURES. DEPARTMENT OF
CIVIL&ENVIRONMENTAL ENGINEERING COLLEGE OF ENGINEERING UNIVERSITY OF CALIFORNIA AT DAVIS
• Robertson, P.K. and Cabal, K.L., 2007, Guide to Cone Penetration Testing for Geotechnical Engineering. Available at no cost at
http://www.geologismiki.gr/
• Robertson, P.K. 1990. Soil classification using the cone penetration test. Canadian Geotechnical Journal, 27 (1), 151-8.
• Robertson, P.K. and Wride, C.E., 1998. Cyclic Liquefaction and its Evaluation based on the CPT Canadian Geotechnical Journal,
1998,Vol. 35, August.
• Youd, T.L., Idriss, I.M., Andrus, R.D., Arango, I., Castro, G., Christian, J.T., Dobry, R., Finn, W.D.L., Harder, L.F., Hynes, M.E.,
Ishihara, K., Koester, J., Liao, S., Marcuson III, W.F., Martin, G.R., Mitchell, J.K., Moriwaki, Y., Power, M.S., Robertson, P.K.,
Seed, R., and Stokoe, K.H., Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF
Workshop on Evaluation of Liquefaction Resistance of Soils, ASCE, Journal of Geotechnical & Geoenvironmental Engineering,
Vol. 127, October, pp 817-833
• Zhang, G., Robertson. P.K., Brachman, R., 2002, Estimating Liquefaction Induced Ground Settlements from the CPT, Canadian
Geotechnical Journal, 39: pp 1168-1180
• Zhang, G., Robertson. P.K., Brachman, R., 2004, Estimating Liquefaction Induced Lateral Displacements using the SPT and CPT,
ASCE,Journal of Geotechnical &Geoenvironmental Engineering,Vol. 130, No. 8, 861-871
• Pradel, D., 1998, Procedure to Evaluate Earthquake-Induced Settlements in Dry Sandy Soils, ASCE, Journal of Geotechnical &
Geoenvironmental Engineering,Vol. 124, No. 4, 364-368
• Iwasaki, T., 1986, Soil liquefaction studies in Japan: state-of-the-art, Soil Dynamics and Earthquake Engineering, Vol. 5, No. 1,
2-70
• Papathanassiou G., 2008, LPI-based approach for calibrating the severity of liquefaction-induced failures and for assessing the
probability of liquefaction surface evidence, Eng. Geol. 96:94-104
• P.K. Robertson, 2009, Interpretation of Cone Penetration Tests - a unified approach., Canadian Geotechnical Journal, Vol. 46,
No. 11, pp 1337-1355
• P.K. Robertson, 2009. "Performance based earthquake design using the CPT", Keynote Lecture, International Conference on
Performance-based Design in Earthquake Geotechnical Engineering -from case history to practice, IS-Tokyo,June 2009
• Robertson, P.K. and Lisheng, S., 2010,"Estimation of seismic compression in dry soils using the CPT"FIFTH INTERNATIONAL
CONFERENCE ON RECENT ADVANCES IN GEOTECHNICAL EARTHQUAKE ENGINEERING AND SOIL DYNAMICS, Symposium in
honor of professor I. M, Idriss,SAN diego,CA
• R. E. S. Moss, R. B. Seed, R. E. Kayen,J. P. Stewart,A. Der Kiureghian, K. 0. Cetin, CPT-Based Probabilistic and Deterministic
Assessment of In Situ Seismic Soil Liquefaction Potential,Journal of Geotechnical and Geoenvironmental Engineering,Vol. 132,
No. 8, August 1, 2006
• I. M. Idriss and R. W. Boulanger, 2008. Soil liquefaction during earthquakes, Earthquake Engineering Research Institute MNO-
12
GeoPaa;itic
Engineering,Inc.
Real-World Geotechnical Solutions
Investigation • Design • Construction Support
INFILTRATION TESTING CALCULATIONS
14835 SW 72nd Avenue Tel (503) 598-8445
Portland, Oregon 97224 Fax(503) 941-9281
GeoPacific Engineering, Inc. Gee acrd
148535 SW 72nd Avenue Engineering,Inc.
Portland, Oregon 97224 Real World Geotechnical Solutions
INFILTRATION TESTING DATA TABLE
Project #: 17-4626 GeoPacific Engineering, Inc.
Project Name: 72nd Avenue Apartments Engineer/Geologist: BLC
Date: July 3, 2017 Test Method: Open Borehole Method
Infiltration Test ID: IT-1.1 Test Depth: -10 Feet
Test Location: Soil Boring B-1 Casing Diameter: 6 inch
Soil Description: CL Embedment Depth: N/A
Elapsed Initial Head Head Height Infiltration Rate
Time Measured
Time (Hours) Height at Time Drop (Inches) (Inches Per
(Minutes) (Inches) H1 (Inches) H2 Hour)
30 0.5 12 12 0 0
60 1 12 12 0 0
120 2 12 12 0 0
180 3 12 12 0 0
240 4 12 12 0 0
Trial #1 Measured Infiltration Rate (inches per hour): 0
Notes:
Test conducted in the bottom of soil boring.
Measurements obtained with a water whistle measuring tape
Presoak period conducted prior to testing
17-4626, Infiltration Testing Calculator 070317
-90^Pii_ 46
dit
GeoPacific Engineering, Inc. COOP
148535 SW 72nd Avenue Engineering,Inc.
Portland, Oregon 97224 Real World Geotechnical Solutions
INFILTRATION TESTING DATA TABLE
Project #: 17-4626 GeoPacific Engineering, Inc.
Project Name: 72nd Avenue Apartments Engineer/Geologist: BLC
Date: July 3, 2017 Test Method: Open Borehole Method
Infiltration Test ID: IT-1.2 Test Depth: -20 Feet
Test Location: Soil Boring B-1 Casing Diameter: 6 inch
Soil Description: ML Embedment Depth: N/A
Elapsed Initial Head Head Height Infiltration Rate
Time Time Measured
Height at Time (Inches Per
(Hours) Drop (Inches)
(Minutes) (Inches) H1 (Inches) H2 Hour)
30 0.5 12 12 0 0
60 1 12 12 0 0
120 2 I 12 12 0 i 0
180 3 12 12 0 0
240 4 12 12 0 0
Trial #1 Measured Infiltration Rate (inches per hour): 0
Notes:
Test conducted in the bottom of soil boring.
Measurements obtained with a water whistle measuring tape
Presoak period conducted prior to testing
17-4626, Infiltration Testing Calculator 070317
_��( ,._
GeoPacific Engineering, Inc. Coo Pacific
148535 SW 72nd Avenue Engineering,Inc.
Portland, Oregon 97224 Real World Geotechnical Solutions
INFILTRATION TESTING DATA TABLE
Project #: 17-4626 GeoPacific Engineering, Inc.
Project Name: 72nd Avenue Apartments Engineer/Geologist: BLC
Date: July 3, 2017 Test Method: Open Borehole Method
Infiltration Test ID: IT-2.1 Test Depth: -5 Feet
Test Location: Soil Boring B-2 Casing Diameter: 6 inch
Soil Description: CL Embedment Depth: N/A
Elapsed Initial Head Head Height Infiltration Rate
Time Time Height at Time Measured (Inches Per
(Minutes) (Hours) (Inches) H1 (Inches) H2 Drop' (Inches) Hour)
30 0.5 12 12 0 0
60 1 12 12 0 0
120 2 12 12 0 0
180 3 12 12 0 0
240 4 12 12 0 0
Trial #1 Measured Infiltration Rate (inches per hour): 0
Notes:
Test conducted in the bottom of soil boring.
Measurements obtained with a water whistle measuring tape
Presoak period conducted prior to testing
17-4626, Infiltration Testing Calculator 070317
-1Y41Pii,
WeGeoPacific Engineering, Inc. GeoP
148535 SW 72nd Avenue Engineering,Inc.
Portland, Oregon 97224 Real World Geotechnical Solutions
INFILTRATION TESTING DATA TABLE
Project #: 17-4626 GeoPacific Engineering, Inc.
Project Name: 72nd Avenue Apartments Engineer/Geologist: BLC
Date: July 3, 2017 Test Method: Open Borehole Method
Infiltration Test ID: IT-2.2 Test Depth: -10 Feet
Test Location: Soil Boring B-2 Casing Diameter: 6 inch
Soil Description: ML Embedment Depth: N/A
Elapsed Initial Head Head Height at Time
Infiltration Rate
Time Time Height Measured
(Hours) g Drop (Inches) (Inches Per
(Minutes) (Inches) H1 (Inches) H2 Hour)
30 0.5 12 12 0 0
60 1 12 12 0 0
120 2 12 12 0 0
180 3 12 12 0 0
240 4 12 12 0 0
Trial #1 Measured Infiltration Rate (inches per hour): 0
Notes:
Test conducted in the bottom of soil boring.
Measurements obtained with a water whistle measuring tape
Presoak period conducted prior to testing
17-4626, Infiltration Testing Calculator 070317
.4"Y\rt1/4..
GeoPacific Engineering, Inc. GeoPacitit r
148535 SW 72nd Avenue Engineering,Inc.
Portland, Oregon 97224 Real World Geotechnical Solutions
INFILTRATION TESTING DATA TABLE
Project #: 17-4626 GeoPacific Engineering, Inc.
Project Name: 72nd Avenue Apartments Engineer/Geologist: BLC
Date: July 3, 2017 Test Method: Open Borehole Method
Infiltration Test ID: IT-2.3 Test Depth: -20 Feet
Test Location: Soil Boring B-2 Casing Diameter: 6 inch
Soil Description: ML Embedment Depth: N/A
Elapsed Initial Head Head Height Infiltration Rate
Time Time Measured
Height at Time (Inches Per
(Minutes) (Hours) (Inches) H1 (Inches) H2 Drop (Inches) Hour)
30 0.5 12 12 0 0
60 1 1 12 12 0 0
120 2 12 12 0 0
180 3 12 12 0 0
240 4 12 12 0 1 0
Trial #1 Measured Infiltration Rate (inches per hour): 0
Notes:
Test conducted in the bottom of soil boring.
Measurements obtained with a water whistle measuring tape
Presoak period conducted prior to testing
17-4626, Infiltration Testing Calculator 070317
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„u , .. ,, ra, ,. �....... .y .,. ..............,. ....... .... ,
1. 17-4626 Engineer: MTB Existing Base Aggregate Thickness: 5 inches 1.5"-0 Crushed
See Figure 2, 5 Feet West of Fog Line Subgrade: Lean CLAY Notes: Test Location - Figure 2
aft I Height(from ref)at start Depth below ground at start Length of shaft Height(from ref)at start Depth below ground at start
cm cm in in in
90.805 41.275 52 35.75 16.25
Height(from ref)I, Height(from ref)cm Depth(below ground)cm Depth(inches below ground) Depth(feet below ground) mm/blow
34.25 87.00 45.09 17.75 1.48 7.62
32.5 82.55 49.53 19.50 1.63 8.89
28.25 71.76 60.33 23.75 1.98 21.59
25.5 64.77 67.31 26.50 2.21 69.85
21.75 55.25 76.84 30.25 2.52 95.25
19 48.26 83.82 33.00 2.75 69.85
17 43.18 88.90 35.00 2.92 50.80
15.75 40.01 92.08 36.25 3.02 31.75
14.5 36.83 95.25 37.50 3.13 31.75
13.5 34.29 97.79 38.50 3.21 25.40
Average 41.28
nor PDCP measurements recorded in inches
ants are after each blow. Mm/blow is difference between previous and current blow
1. 17-4626 Engineer: MTB Existing Base Aggregate Thickness: 4 inches 1.5"-0 Crushed
See Figure 2, 4 Feet West of Fog Line Subgrade: Lean CLAY Notes: Test Location - Figure 2
aft I Height(from ref)at start Depth below ground at start Length of shaft Height(from ref)at start Depth below ground at start
cm cm in in in
95.25 36.83 52 37.5 14.5
Height(from ref)in Height(from ref)cm Depth(below ground)cm Depth(inches below ground) Depth(feet below ground) mm/blow
34 86.36 45.72 18.00 1.50 17.78
28.75 73.03 59.06 23.25 1.94 44.45
26.5 67.31 64.77 25.50 2.13 57.15
25 63.50 68.58 27.00 2.25 38.10
23.75 60.33 71.76 28.25 2.35 31.75
22.25 56.52 75.57 29.75 2.48 38.10
21 53.34 78.74 31.00 2.58 31.75
19.75 50.17 81.92 32.25 2.69 31.75
18 45.72 86.36 34.00 2.83 44.45
16.5 41.91 90.17 35.50 2.96 38.10
Average 37.34
br PDCP measurements recorded in inches
ants are after each blow. Mm/blow is difference between previous and current blow
1. 17-4626 Engineer: MTB Existing Base Aggregate Thickness: 7 inches 1.5"-0 Crushed
See Figure 2, 6 Feet West of Fog Line Subgrade: Lean CLAY Notes: Test Location - Figure 2
aft I Height(from ref)at start Depth below ground at start Length of shaft ieight(from ref)at start Depth below ground at start
cm cm in in in
95.25 36.83 52 37.5 14.5
Height(trom ret)s Height(from ref)cm Depth(below ground)cm Depth(inches below ground) Depth(feet below ground) mm/blow
35.75 90.81 41.28 16.25 1.35 8.89
34.75 88.27 43.82 17.25 1.44 5.08
33.5 85.09 46.99 18.50 1.54 6.35
32.75 83.19 48.90 19.25 1.60 3.81
31.5 80.01 52.07 20.50 1.71 6.35
30.5 77.47 54.61 21.50 1.79 5.08
29.5 74.93 57.15 22.50 1.88 5.08
28.25 71.76 60.33 23.75 1.98 6.35
26.25 66.68 65.41 25.75 2.15 10.16
21.75 55.25 76.84 30.25 2.52 22.86
Average 8.00
'or PDCP measurements recorded in inches
ants are after each blow. Mm/blow is difference between previous and current blow
DARWin(tm) - Pavement Design
A Proprietary AASHTOWARE(tm)
Computer Software Product
Flexible Structural Design Module
Project Description
17-4626, 72nd Avenue Apartments, Existing Pavement Evaluation of East Lane
- 72nd Avenue - RC-1
Flexible Structural Design Module Data
18-kip ESALs Over Initial Performance Period: 3, 829, 800
Initial Serviceability: 4.2
Terminal Serviceability: 2.5
Reliability Level (%) : 90
Overall Standard Deviation: .5
Roadbed Soil Resilient Modulus (PSI) : 15, 000
Stage Construction: 1
Calculated Structural Number: 3.41
Specified Layer Design
Layer: 1
Material Description: Existing Asphalt
Structural Coefficient (Ai) : .4
Drainage Coefficient (Mi) : 1
Layer Thickness (Di) (in) : 10.50
Calculated Layer SN: 4 .20
Layer: 2
Material Description: Existing Crushed Aggregate
Structural Coefficient (Ai) : .1
Drainage Coefficient (Mi) : 1
Layer Thickness (Di) (in) : 5.00
Calculated Layer SN: .50
Total Thickness (in) : 15.50
Total Calculated SN: 4.70
DARWin(tm) - Pavement Design
A Proprietary AASHTOWARE(tm)
Computer Software Product
Flexible Structural Design Module
Project Description
17-4626, 72nd Avenue Apartments, Existing Pavement Evaluation of East Lane
- 72nd Avenue - RC-2
Flexible Structural Design Module Data
18-kip ESALs Over Initial Performance Period: 3,829, 800
Initial Serviceability: 4.2
Terminal Serviceability: 2.5
Reliability Level (%) : 90
Overall Standard Deviation: .5
Roadbed Soil Resilient Modulus (PSI) : 7,500
Stage Construction: 1
Calculated Structural Number: 4.40
Specified Layer Design
Layer: 1
Material Description: Existing Asphalt
Structural Coefficient (Ai) : .4
Drainage Coefficient (Mi) : 1
Layer Thickness (Di) (in) : 10.00
Calculated Layer SN: 4.00
Layer: 2
Material Description: Existing Crushed Aggregate
Structural Coefficient (Ai) : .1
Drainage Coefficient (Mi) : 1
Layer Thickness (Di) (in) : 4.00
Calculated Layer SN: .40
Total Thickness (in) : 14.00
Total Calculated SN: 4.40
DARWin(tm) - Pavement Design
A Proprietary AASHTOWARE(tm)
Computer Software Product
Flexible Structural Design Module
Project Description
17-4626, 72nd Avenue Apartments, Existing Pavement Evaluation of East Lane
- 72nd Avenue - RC-3
Flexible Structural Design Module Data
18-kip ESALs Over Initial Performance Period: 3, 829, 800
Initial Serviceability: 4.2
Terminal Serviceability: 2.5
Reliability Level (%) : 90
Overall Standard Deviation: .5
Roadbed Soil Resilient Modulus (PSI) : 50, 000
Stage Construction: 1
Calculated Structural Number: 2.14
Specified Layer Design
Layer: 1
Material Description: Existing Asphalt
Structural Coefficient (Ai) : .4
Drainage Coefficient (Mi) : 1
Layer Thickness (Di) (in) : 6.50
Calculated Layer SN: 2.60
Layer: 2
Material Description: Existing Crushed Aggregate
Structural Coefficient (Ai) : .1
Drainage Coefficient (Mi) : 1
Layer Thickness (Di) (in) : 7.00
Calculated Layer SN: .70
Total Thickness (in) : 13.50
Total Calculated SN: 3.30
DARWin(tm) - Pavement Design
A Proprietary AASHTOWARE(tm)
Computer Software Product
Flexible Structural Design Module
Project Description
17-4626, 72nd Avenue Apartments, New Pavement, Streeet Widening 72nd
Avenue, East Lane, 20 Year Pavement Design
Flexible Structural Design Module Data
18-kip ESALs Over Initial Performance Period: 3,829,800
Initial Serviceability: 4.2
Terminal Serviceability: 2.5
Reliability Level (%) : 90
Overall Standard Deviation: .5
Roadbed Soil Resilient Modulus (PSI) : 7,500
Stage Construction: 1
Calculated Structural Number: 4.40
Specified Layer Design
Layer: 1
Material Description: New Asphalt
Structural Coefficient (Ai) : .42
Drainage Coefficient (Mi) : 1
Layer Thickness (Di) (in) : 8.00
Calculated Layer SN: 3.36
Layer: 2
Material Description: 3/4"-0 Crushed Aggregate
Structural Coefficient (Ai) : .1
Drainage Coefficient (Mi) : 1
Layer Thickness (Di) (in) : 2.00
Calculated Layer SN: .20
Layer: 3
Material ) srription: 1.5"-0 Crushed Aggregate
Structural Coefficient (Ai) : .1
Drainage Coefficient (Mi) : 1
Layer Thickness (Di) (in) : 10.00
Calculated Layer SN: 1.00
Total Thickness (in) : 20.00
Total Calculated SN: 4.56
DARWin(tm) - Pavement Design
A Proprietary AASHTOWARE(tm)
Computer Software Product
Flexible Structural Design Module
Project Description
17-4626, 72nd Avenue Apartments, New Pavement, Private Parking Areas, 20
Year Pavement Design
Flexible Structural Design Module Data
18-kip ESALs Over Initial Performance Period: 100, 000
Initial Serviceability: 4.2
Terminal Serviceability: 2.5
Reliability Level (%) : 90
Overall Standard Deviation: .5
Roadbed Soil Resilient Modulus (PSI) : 7,500
Stage Construction: 1
Calculated Structural Number: 2.43
Specified Layer Design
Layer: 1
Material Description: New Asphalt
Structural Coefficient (Ai) : .42
Drainage Coefficient (Mi) : 1
Layer Thickness (Di) (in) : 3.50
Calculated Layer SN: 1.47
Layer: 2
Material Description: 3/4"-0 Crushed Aggregate
Structural Coefficient (Ai) : .1
Drainage Coefficient (Mi) : 1
Layer Thickness (Di) (in) : 2.00
Calculated Layer SN: .20
Layer: 3
Material Description: 1.5"-0 Crushed Aggregate
Structural Coefficient (Ai) : .1
Drainage Coefficient (Mi) : 1
Layer Thickness (Di) (in) : 8.00
Calculated Layer SN: .80
Total Thickness (in) : 13.50
Total Calculated SN: 2.47
DARWin(tm) - Pavement Design
A Proprietary AASHTOWARE(tm)
Computer Software Product
Rigid Structural Design Module
Project Description
17-4626, 72nd Avenue Apartments, New Pavement, Concrete Pavement, Private
Parking Areas, 20 Year Pavement Design
Rigid Structural Design Module Data
Pavement type: JPCP
18-kip ESALs for initial performance period: 100, 000
Initial Serviceability: 4 .2
Terminal Serviceability: 2.1
28-day mean PCC Modulus of Rupture (psi) : 650
28-day mean Elastic Modulus of Slab (psi) : 3, 500, 000
Mean Effective k-value (pci) : 38.65
Reliability Level (%) : 90
Overall Standard Deviation: .42
Load Transfer Coefficient: 3
Overall Drainage Coefficient: 1
Stage Construction: 1
Calculated Design Thickness (in) : 4.90
Additional Pavement Layers
Layer Number: 2
Material Type: 3/4"-0 Crushed Agg
Description: Leveling Course
Thickness (in) : 2.00
Layer Number: 3
Material Type: 1.5"-0 Crushed Agg
Description: Base Course
Thickness (in) : 6.00
GeoPaitic
Engineering,Inc.
Real-World Geotechnical Solutions
Investigation • Design • Construction Support
SITE RESEARCH
14835 SW 72nd Avenue Tel (503) 598-8445
Portland, Oregon 97224 Fax(503) 941-9281
Soil Map—Washington County, Oregon
MAP LEGEND MAP INFORMATION
Area of Interest(AOI) Spoil Area The soil surveys that comprise your AOI were mapped at
Area of Interest(AOI) 1:20,000.
a Stony Spot
Soils as Very Stony Spot Warning: Soil Map may not be valid at this scale.
Soil Map Unit Polygons
Wet Spot Enlargement of maps beyond the scale of mapping can cause
Soil Map Unit Lines misunderstanding of the detail of mapping and accuracy of soil
, Other line placement.The maps do not show the small areas of
CI Soil Map Unit Points
Special Line Features contrasting soils that could have been shown at a more detailed
Special Point Features scale.
t Blowout Water Features
Streams and Canals Please rely on the bar scale on each map sheet for map
Borrow Pit measurements.
Transportation
st Clay Spot4-0-4 Rails Source of Map: Natural Resources Conservation Service
Closed Depression Web Soil Survey URL:
Interstate Highways Coordinate System: Web Mercator(EPSG:3857)
Gravel Pit US Routes
Maps from the Web Soil Survey are based on the Web Mercator
Gravelly Spot Major Roads projection,which preserves direction and shape but distorts
distance and area.A projection that preserves area,such as the
Landfill Local Roads Albers equal-area conic projection,should be used if more
aa Lava Flow accurate calculations of distance or area are required.
A. Background
.44 Marsh or swamp r Aerial Photography This product is generated from the USDA-NRCS certified data as
of the version date(s)listed below.
Mine or Quarry
Soil Survey Area: Washington County,Oregon
Miscellaneous Water Survey Area Data: Version 14, Sep 16,2016
Perennial Water Soil map units are labeled(as space allows)for map scales
Rock Outcrop 1:50,000 or larger.
Saline Spot Date(s)aerial images were photographed: Aug 3,2014—Aug
23,2014
Sandy Spot
The orthophoto or other base map on which the soil lines were
Severely Eroded Spot compiled and digitized probably differs from the background
imagery displayed on these maps.As a result, some minor
Sinkhole shifting of map unit boundaries may be evident.
Slide or Slip
Sodic Spot
t:si A Natural Resources Web Soil Survey 7/17/2017
Conservation Service National Cooperative Soil Survey Page 2 of 3
Soil Map—Washington County,Oregon
Map Unit Legend
Washington County,Oregon(OR067)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
37B Quatama loam,3 to 7 percent 11.1 100.0%
slopes
Totals for Area of Interest 11.1 100.0%
tIsm Natural Resources Web Soil Survey 7/17/2017
mosi Conservation Service National Cooperative Soil Survey Page 3 of 3
7/17/2017 Design Maps Summary Report
USGS Design Maps Summary Report
User-Specified Input
Report Title 17-4626, SW 72nd Avenue Apartments
Tue July 18, 2017 00:21:11 UTC
Building Code Reference Document ASCE 7-10 Standard
(which utilizes USGS hazard data available in 2008)
Site Coordinates 45.43526°N, 122.75089°W
Site Soil Classification Site Class D - "Stiff Soil"
Risk Category I/II/III
.: - •lortl�rnd
Gresha
Beaverton i ..
10 II
: '
pswego
99
'Y SherWciod ...,r 1,,
•
t
-' ' ` Ore .
USGS-Provided Output
SS = 0.981 g SMS = 1.087 g SDs = 0.724 g
Si = 0.424 g 5M1 = 0.668 g SD1 = 0.445 g
For information on how the SS and S1 values above have been calculated from probabilistic (risk-targeted) and
deterministic ground motions in the direction of maximum horizontal response, please return to the application and
select the "2009 NEHRP" building code reference document.
M::5.,Re ::c,•ise Spects.i-n 7cs:j•i Response Spectr in
s;a
1,10 U 83
GS* O 72
Q&i 0 0'.
x;
ate' I N 047
a 4t 0 52
as` 02t
Q21 Q 1t
QIt 0011
'aCrj
ti 87 t 03 '. '_` 1.4.0 ,3 047 0.W 080 1.03 133 i t, ':o l,80 203
Period.i(sec) Period,1(sec)
For PGA,, TL, CRS, and CR, values, please view the detailed report.
Although this information is a product of the U.S. Geological Survey, we provide no warranty, expressed or implied, as to the
accuracy of the data contained therein.This tool is not a substitute for technical subject-matter knowledge.
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7/17/2017 Design Maps Detailed Report
"ig-LISGSDesign Maps Detailed Report
ASCE 7-10 Standard (45.43526°N, 122.75089°W)
Site Class D - "Stiff Soil", Risk Category I/II/III
Section 11.4.1 — Mapped Acceleration Parameters
Note: Ground motion values provided below are for the direction of maximum horizontal
spectral response acceleration. They have been converted from corresponding geometric
mean ground motions computed by the USGS by applying factors of 1.1 (to obtain SS) and
1.3 (to obtain Si). Maps in the 2010 ASCE-7 Standard are provided for Site Class B.
Adjustments for other Site Classes are made, as needed, in Section 11.4.3.
From Figure 22-1 Ell Ss = 0.981 g
From Figure 22-2[2] S1 = 0.424 g
Section 11.4.2 — Site Class
The authority having jurisdiction (not the USGS), site-specific geotechnical data, and/or
the default has classified the site as Site Class D, based on the site soil properties in
accordance with Chapter 20.
Table 20.3-1 Site Classification
Site Class vs Nor NCh s„
A. Hard Rock >5,000 ft/s N/A N/A
B. Rock 2,500 to 5,000 ft/s N/A N/A
C. Very dense soil and soft rock 1,200 to 2,500 ft/s >50 >2,000 psf
D. Stiff Soil 600 to 1,200 ft/s 15 to 50 1,000 to 2,000 psf
E. Soft clay soil <600 ft/s <15 <1,000 psf
Any profile with more than 10 ft of soil having the
characteristics:
• Plasticity index PI > 20,
• Moisture content w 240%, and
• Undrained shear strength s < 500 psf
F. Soils requiring site response See Section 20.3.1
analysis in accordance with Section
21.1
For SI: lft/s = 0.3048 m/s llb/ft2 = 0.0479 kN/m2
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7/17/2017 Design Maps Detailed Report
Section 11.4.3 - Site Coefficients and Risk-Targeted Maximum Considered Earthquake (MCEB.)
Spectral Response Acceleration Parameters
Table 11.4-1: Site Coefficient Fa
Site Class Mapped MCE R Spectral Response Acceleration Parameter at Short Period
Ss 0.25 S5 = 0.50 SS = 0.75 Ss = 1.00 Ss 1.25
A 0.8 0.8 0.8 0.8 0.8
B 1.0 1.0 1.0 1.0 1.0
C 1.2 1.2 1.1 1.0 1.0
D 1.6 1.4 1.2 1.1 1.0
E 2.5 1.7 1.2 0.9 0.9
F See Section 11.4.7 of ASCE 7
Note: Use straight-line interpolation for intermediate values of Ss
For Site Class = D and SS = 0.981 g, Fa = 1.108
Table 11.4-2: Site Coefficient F„
Site Class Mapped MCE R Spectral Response Acceleration Parameter at 1-s Period
5, 5 0.10 S, = 0.20 S, = 0.30 5, = 0.40 S, >_ 0.50
A 0.8 0.8 0.8 0.8 0.8
B 1.0 1.0 1.0 1.0 1.0
C 1.7 1.6 1.5 1.4 1.3
D 2.4 2.0 1.8 1.6 1.5
E 3.5 3.2 2.8 2.4 2.4
F See Section 11.4.7 of ASCE 7
Note: Use straight-line interpolation for intermediate values of S1
For Site Class = D and S, = 0.424 g, F„ = 1.576
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7/17/2017 Design Maps Detailed Report
Equation (11.4-1): SMS = FaSs = 1.108 x 0.981 = 1.087 g
Equation (11.4-2): SM1 = Fv1 S = 1.576 x 0.424 = 0.668 g
Section 11.4.4 — Design Spectral Acceleration Parameters
Equation (11.4-3): SDS = % SMS = 2/3 x 1.087 = 0.724 g
Equation (11.4-4): SD1 = 2/3 SM1 = 2/3 x 0.668 = 0.445 g
Section 11.4.5 — Design Response Spectrum
From Figure 22-12[31 T, = 16 seconds
Figure 11.4-1: Design Response Spectrum
T<T0:Sa=So.(0.4+0.6T/To)
T.5T5T.:Sa=So$
Sr.-0.724
Ts<T5TL:So=So,/T
0 T>TL:So=SD,T,./T2
S,„_33.445
4
.1 s :.615 1.O
Period.T(see)
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7/17/2017 Design Maps Detailed Report
Section 11.4.6 — Risk-Targeted Maximum Considered Earthquake (MCER) Response Spectrum
The MCER Response Spectrum is determined by multiplying the design response spectrum above by
1.5.
S,E 1.087 -
to
SN,-0.668
Tc 0,123 Ts-0.615 1.600
Penact T(se )
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7/17/2017 Design Maps Detailed Report
Section 11.8.3 - Additional Geotechnical Investigation Report Requirements for Seismic Design
Categories D through F
From Figure 22-7[41 PGA = 0.428
Equation (11.8-1): PGA,, = FPGAPGA = 1.072 x 0.428 = 0.459 g
Table 11.8-1: Site Coefficient FPGA
Site Mapped MCE Geometric Mean Peak Ground Acceleration, PGA
Class
PGA <_ PGA = PGA = PGA = PGA >_
0.10 0.20 0.30 0.40 0.50
A 0.8 0.8 0.8 0.8 0.8
B 1.0 1.0 1.0 1.0 1.0
C 1.2 1.2 1.1 1.0 1.0
D 1.6 1.4 1.2 1.1 1.0
E 2.5 1.7 1.2 0.9 0.9
F See Section 11.4.7 of ASCE 7
Note: Use straight-line interpolation for intermediate values of PGA
For Site Class = D and PGA = 0.428 g, FPGA = 1.072
Section 21.2.1.1 - Method 1 (from Chapter 21 - Site-Specific Ground Motion Procedures for
Seismic Design)
From Figure 22-17 [5] CRS = 0.899
From Figure 22-18[6] CR1 = 0.871
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7/17/2017 Design Maps Detailed Report
Section 11.6 — Seismic Design Category
Table 11.6-1 Seismic Design Category Based on Short Period Response Acceleration Parameter
RISK CATEGORY
VALUE OF SDs
I or iI III IV
Sps < 0.167g A A A
0.167g <_ Sps < 0.33g B B C
0.33g <_ Sps < 0.50g C C D
0.50g <_ Sps D D D
For Risk Category = I and SD, = 0.724 g, Seismic Design Category = D
Table 11.6-2 Seismic Design Category Based on 1-S Period Response Acceleration Parameter
RISK CATEGORY
VALUE OF SD1
I or II III IV
SDI < 0.067g A A A
0.067g < SD1 < 0.133g B B C
0.133g <_ SDI < 0.20g C C D
0.20g <_ SpI D D D
For Risk Category = I and S0, = 0.445 g, Seismic Design Category = D
Note: When S1 is greater than or equal to 0.75g, the Seismic Design Category is E for
buildings in Risk Categories I, II, and III, and F for those in Risk Category IV, irrespective
of the above.
Seismic Design Category - "the more severe design category in accordance with
Table 11.6-1 or 11.6-2" = D
Note: See Section 11.6 for alternative approaches to calculating Seismic Design Category.
References
1. Figure 22-1: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-1.pdf
2. Figure 22-2: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-2.pdf
3. Figure 22-12: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-12.pdf
4. Figure 22-7: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-7.pdf
5. Figure 22-17: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-17.pdf
6. Figure 22-18: https://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-18.pdf
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Portland, Oregon 97224 Fax(503) 941-9281