Report (2) Carlson Geotechn Mailing Address Main Office
A Division of Carlson Testing, Inc. P.O. Box 23814 7185 SW Sandburg Street, #110
Geotechnical Consulting Tigard, Oregon 97281 Tigard, Oregon 97223
9 Phone (503) 601 -8250
Serving Oregon & SW Washington Fax (503) 601 -8254
I 2 Co I 7 5 IA/ J
CAP Loce -
OFFICE COPY
Report of
Geotechnical Investigation and
Site - Specific Seismic Hazards Study
Tigard Fire Station
12585 SW Walnut Street
Tigard, Oregon
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CGT Project Number G0602953 • " "•
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Prepared for
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Mr. Gary Wells •
Tualatin Valley Fire and Rescue • •' • • •
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20665 SW Blanton Street • •
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Beaverton, Oregon 97007
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January 9, 2007
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Carlson Geotechnical Mailing Address Main Office
P.O. Box 23814 7185 SW Sandburg Street, #110
A Division of Carlson Testing, Inc. Tigard, Oregon 97281 Tigard, Oregon 97223
Geotechnical Consulting Phone (503) 601 -8250
Serving Oregon & SW Washington Fax (503) 601 -8254
January 9, 2007
Mr. Gary Wells
Tualatin Valley Fire and Rescue
20665 SW Blanton Street
Beaverton, Oregon 97007
Report of
Geotechnical Investigation and
Site - Specific Seismic Hazards Study
Tigard Fire Station
12585 SW Walnut Street
Tigard, Oregon
CGT Project Number G0602953
Dear Mr. Wells:
Carlson Geotechnical (CGT) is pleased to submit the results of our Report of Geotechnical
Investigation and Site - Specific Seismic Hazards Study for the Tigard Fire Station site located at
12585 SW Walnut Street in Tigard, Oregon. The development will consist of a single -story,
three -bay, fire station with appurtenant pavements and utilities. CGT performed our work in
general accordance with CGT Proposal PO4146, dated October 6, 2006. You provided w rittgn • •
authorization for our services on October 13, 2006. Initial fieldwork, conduct�l,pb NoJ
27, 2006, encountered medium stiff to soft soils to depths of up to about 50 feet blow grQi M •
surface. On November 27, 2006, CGT recommended that a Cone Pendttameter Tes • be . .
conducted at the site. You provided authorization for the additional work ptCNavembrer 27 +
•
2006.
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CGT appreciates the opportunity to work with you on this project. Please al'r�du have any • •
questions regarding this report.
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Sincerely, ... • • • •
Carlson Geotechnical
Ryan T. Houser, CEG David P. Holt, PE
Senior Engineering Geologist Senior Geotechnical Engineer
Attachments
TABLE OF CONTENTS
INTRODUCTION 5
PROJECT INFORMATION AND SITE DESCRIPTION 6
Project Information 6
Regional Geology 7
Site Geology 7
Earthquake Sources and Seismicity 8
Crustal Sources 8
Intra -Slab Source 12
Cascadia Subduction Zone (CSZ) 13
Earthquake Magnitude 13
Maximum Credible Earthquake (Deterministic) 14
Maximum Probable Earthquake (Probabilistic) 14
Seismic Shaking 15
Site Surface Conditions 18
Site Subsurface Conditions 18
Field Exploration 18
Subsurface Materials 19
Groundwater 19
Liquefaction ..YY.•: •; ;a9
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CONCLUSIONS • •••• ..:•20
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Seismic Hazards • •
General ,, ••
RECOMMENDATIONS ;• • ;;� � ,,.�; •
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Site Preparation
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Wet Weather Considerations 23
Structural Fill 24
On -Site Materials 24
Imported Granular Structural Fill 25
Shallow Foundations 25
Bearing Pressure and Settlement 25
Lateral Capacity 26
Drainage 26
Floor Slabs 27
Pavement Subgrades 28
Additional Drainage Considerations 28
Utility Trenches 28
Utility Trench Excavation 28
Trench Backfill Material 29
Seismic Design 29
OBSERVATION OF CONSTRUCTION 30
LIMITATIONS 31
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Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
INTRODUCTION
This report presents the results of our geotechnical investigation and site - specific seismic
hazards study for the Tigard Fire Station site located at 12585 SW Walnut Street in Tigard,
Oregon. The location of the site is shown on the attached Site Location, Figure 1. The purpose
of our geotechnical investigation was to explore subsurface conditions at the site in order to
provide geotechnical engineering recommendations for the proposed fire station. The purpose
of our site - specific seismic hazards study was to identify seismic hazards that may impact the
site, including liquefaction potential. Our specific scope of services included the following:
• Explore subsurface conditions at the site by advancing three (3) hollow -stem-
auger soil borings in the vicinity of the proposed fire station. One boring was
advanced to a depth of about 51% feet below ground surface (bgs) for use in the
liquefaction analysis. The other two borings were advanced to depths of
approximately 21% feet bgs. The borings were advanced by Subsurface
Technologies of North Plains, Oregon, using a truck- mounted drill rig equipped
with hollow- stem - augers.
• Perform Standard Penetration Tests (SPTs) within the hollow- stem -auger
borings at 2% -foot intervals to depths of 15 feet bgs, and then at 5 -foot intervals
to the termination depths of the borings. The SPTs were performed in general
•••• • •
accordance with American Society for Testing and Materials (ASTM) DUN : ' • • • •'
• Explore deeper subsurface conditions at the site by performing a .cone : • • • '
penetrometer test (CPT) within the building footprint to a depth of about 71 feet • •
bgs. The CPT was conducted using a truck- mounted cone penetrgr=tejer rig • •
provided and operated by Subsurface Technologies. • • • • • • •
• • • •••
• Classify the materials encountered in the explorations as per AS117I'02488 • . • : ' •
(Visual - Manual Procedure). A qualified member of CGT's staff obSptved the •
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• explorations and maintained a detailed log of each boring. • • • • • •
• • Collect representative disturbed samples of the soils encountered within the ••••••
borings in order to perform laboratory testing and to confirm our field •• • ' •••• .
classifications.
• Complete eleven (11) moisture content determinations on select samples from
the borings. The moisture content tests were performed in general accordance
with ASTM D2216.
• Complete three (3) Atterberg limits (plasticity) tests on select samples obtained
from the borings. The plasticity tests were performed in general accordance with
ASTM 04318.
Carlson Geotechnical Page 5 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
• Complete nine (9) percent passing the U.S. Standard No. 200 Sieve tests on
select samples from the borings. The sieve tests were performed in general
accordance with ASTM C117.
• Provide a site - specific seismic hazards study in general accordance with the
requirements of Section 1802 of the 2003 International Building Code, and
Section 1802 of the 2004 Oregon Structural Specialty Code.
• Quantitatively evaluate liquefaction potential of the soils encountered within the
depths explored.
• Provide recommendations for site preparation, grading and drainage, stripping
depths, fill type for imported materials, compaction criteria, cut and fill slope
criteria, trench excavation and backfill, use of on -site soils, and wet/dry weather
earthwork.
• Provide geotechnical engineering recommendations for design and construction
of shallow spread foundations, including an allowable design bearing pressure,
and minimum footing depth and width requirements.
• _ Provide geotechnical engineering recommendations for design and construction
of concrete floor slabs, including an anticipated value for subgrade modulus, and
recommendations for a capillary break and vapor retarder.
• Estimate settlement of footings and floor slabs for the provided design loading.
• Provide recommendations for pavement subgrade preparation.
• Provide recommendations for the International Building Code (IBC) Site Class, •••• • •
mapped maximum considered earthquake spectral response acceleratiolas: site • ••••
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seismic coefficients, •and Seismic Design Category. : "' •
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• Provide a written report summarizing the results of our geotechnical in'estigation • •
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and site- specific seismic hazards study. • . • • •
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PROJECT INFORMATION AND SITE DESCRIPTION •• •
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Project Information •
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We understand that the development will consist of the construction of a single -story, thre ••••••
fire station with appurtenant pavements and utilities, and that the existing residence and barn
will be razed prior to construction of the fire station. We anticipate that the new structure will be
constructed utilizing a slab -on -grade with masonry walls and a wood roof. Based on structural
loading information provided by Peck Smiley Ettlin Architects, we understand that the building
will have continuous perimeter footing loads of less than 1% kips per lineal foot (kit), interior
column loads of less than 10 kips, and uniform floor slab loads of less than 150 psf. Based on
topography at the site and the site plan you provided, it is assumed that proposed grades will
be within 3 feet of the existing site surface elevations.
Carlson Geotechnical Page 6 of 32
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Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
— Regional Geology
The site is located in the Tualatin Valley, which is a northwest - southeast trending valley
bordered by the Portland Hills to the north, the Tualatin Mountains to the east, the.Chehalem
Mountains to the south, and the Oregon Coast Range to the west. The Tualatin Valley is an
extension of the Willamette Valley, which was formed when the volcanic rocks of the Oregon
Coast Range, originally formed as submarine islands, were added onto the North American
Continent'. The addition of the volcanic rocks caused inland down - warping, forming a
depression in which various types of marine sedimentary rocks accumulated. Approximately
15 million years ago, these marine sediments were, in turn, covered by Columbia River Basalts
that flowed down the Columbia River Gorge and Willamette Valley, as far south as Salem,
Oregon. Later, uplift and tilting of these Columbia River Basalts, the Oregon Coast Range, and
the western Cascade Range formed the trough -like character of the Willamette and Tualatin
Valleys that we observe today. The Tualatin Valley was subsequently filled with non - marine
clay, silt, sand, and a few gravel units derived from weathering of the adjacent hills. Local
volcanic activity produced the Boring Lavas through several localized vents, including Mt. .
Sylvania, Mt. Scott, and Mt. Tabor. Catastrophic floods later washed into the Willamette and
Tualatin Valleys approximately 12,000 to 15,000 years ago and deposited fine- grained
sedimentary assemblages (Pleistocene Flood Deposits) mapped throughout the area
Site Geology
•••• • •
Available geological mapping of the area indicates that the site is underlain by Pleisiocene•Age,
fine- grained, catastrophic, flood deposits (originating from glacial outburst floods of t:eke • • •
Missoula), consisting of silt and sand, extending to depths of approximately '60 feet bgs. The • •
Pleistocene Lake Missoula catastrophic flood deposits were produced by the• faitrApf •
•
glacial ice dams, which impounded Lake Missoula between 15,000 and 121 00 yrs • o
ea ag • •. • •
Floodwaters raged through eastern Washington and through the Columbia ROM' Gorge. ar •
Rainier, Oregon, the river channel was restricted, causing floodwaters • to. back up the •
Willamette Valley as far south as Eugene, Oregon. Floodwaters in the Portiend etea we •
much as 400 feet deep, leaving only the tops of the tallest hills dry. The fl8ae •
••••
1 Schbcker, H.G., amd Newhouse, C.J., 1967. Engineering Geology of Tualatin Valley Region. Oregon Department of Geology
and Mineral Industries; Bulletin 60.
2 Wilson, 1998. Post - middle Miocene geologic evolution of the Tualatin basin, Oregon. Doyle C. Wilson. Oregon Geology
Volume 60, Number 5, pp. 99, published by Oregon Department of Geology and Mineral Industries, September /October 1998.
3 Bela, James L., 1981, Geology of the Rickreall, Salem West, Monmouth, and Sidney 7W Quadrangles, Marion, Polk, and Linn
Counties, Oregon: Oregon Department of Geology and Mineral Industries Map GMS -18, 2 plates.
Orr, Elizabeth L., Orr, William N., and Baldwin, Ewart M., 1992, Geology of Oregon, Fourth Edition Kendall/Hunt Publishing,
pp. 203 -222.
5 O'Connor, Jim E., et al., 2001, Origin, extent, and thickness of quaternary geologic units in the Willamette Valley, Oregon: US
Geological Survey, Professional Paper 1620,52p, 1 plate.
6 Beeson, M.H., and Tolan, T.L., 1991. Geologic Map of the Portland Quadrangle, Multnomah and Washington Counties,
Oregon, and Clark County, Washington. Oregon Department of Geology and Mineral Industries, Geological Map Series GMS-
75, 1:24,000 scale.
Carlson Geotechnical Page 7 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
typically split into three different facies; the coarse - grained fades, the fine- grained facies, and
the channel facies, which consists of silts, sands, and gravels deposited within the flood
channel. The total thickness of the catastrophic flood deposits varies greatly from
approximately 30 feet to more than 200 feet thick'.
Earthquake Sources and Seismicity
The site is located in a tectonically active area that may be affected by crustal earthquakes,
intra -slab earthquakes, or large subduction zone earthquakes. Damaging crustal earthquakes
in this region may be derived from local sources such as the Portland Hills Fault Zone, the
Beaverton Fault, the Helvetia Fault, the Damascus - Tickle Creek Fault Zone, the Bolton Fault,
the Yamhill- Sherwood Structural Zone, the Mount Angel, Newberg, and Gales Creek Faults,
and several unnamed faults located within a few miles of the site. Crustal earthquakes typically
occur at depths ranging from 15 to 40 km (9 to 25 miles) bgs Intra -slab earthquakes occur
within the subducting Juan De Fuca Plate at depths ranging from approximately 40 km to 70 km
(25 to 43 miles) bgs. Large subduction zone earthquakes in this region are derived from the
Cascadia Subduction Zone (CSZ). Due to the lack of historical data on large subduction zone
earthquakes, a typical depth for the occurrence of a subduction zone earthquake was inferred
from models presented by Geomatrix Consultants in 1995 and is roughly 10 to 25 km bgs (6
to 15 miles).
Crustal Sources • • ▪ • '
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•
The Portland Hills Fault Zone, the Beaverton Fault, the Helvetia Fault, the NpgrAscus '
Creek Fault Zone, the Bolton Fault, the Yamhill- Sherwood Structural Zone, ll;g Angel, •••
Newberg, and Gales Creek Faults and several unnamed faults located within a•few milesof •ti' o
• •
site are the sources for crustal earthquakes in this region. • • • • • • • • • •'
• • • • •
Portland Hills Fault Zone • • • • •
The Portland Hills Fault Zone is a series of northwest - trending faults located •alpproximatay • • •
miles (9.6 km) northeast of the site. The faults associated with this structural zone veitivellye • •
displace the Columbia River Basalt Group by 1,130 feet, and appear to control thickness
changes in late Pleistocene (approximately 780,000 years) sediment The fault zone extends
along the eastern margin of the Portland Hills for a distance of 25 miles (40 km), and has been
• ' Madin, Ian 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.
° Geomatrix Consultants, 1995. Seismic Design Mapping, State of Oregon: unpublished report prepared for Oregon
Department of Transportation, Personal Services Contract 11688, January 1995.
6 Geomatrix Consultants, 1995. Ibid.
70 Mabey, M.A., Madin, I P., Youd, T.L., Jones, C.F., 1993, Earthquake hazard maps of the Portland quadrangle, Multnomah and
Washington Counties, Oregon, and Clark County, Washington: Oregon Department of Geology and Mineral Industries
Geological Map Series GMS -79, Plate 2, 1:24,000.
Carlson Geotechnical - Page 8 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
mapped in the Portland area as a series of inferred faults with no surface expression.
Geomorphic lineaments suggestive of Pleistocene deformation have been identified within the
fault zone, but none of the fault segments has been shown to cut Holocene (last 10,000 years)
deposits' The fact that the faults do not cut Holocene sediments is most likely a result of
the faulting being related to a time of intense uplift of the Oregon Coast Range during Miocene
time, and little to no movement along the faults during the Holocene.
Recent studies of this fault concluded that the Portland Hills Fault Zone is potentially active,
based on contemporary seismicity in the vicinity of the fault, and seismic reflection data
suggesting that the fault cuts late Pleistocene layered strata. Additionally, in May of 2000, while
taking magnetic readings to map the fault, an Oregon Department of Geology and Mineral
Industries (DOGAMI) geologist observed folded sediment in a retaining wall cut in North
Clackamas Park south of Portland. The folded sediments consisted of sand and silt deposited
by Pleistocene floods derived from glacial Lake Missoula approximately 12,800 to 15,000 years
ago. An investigation of the folded strata by DOGAMI geologists, and engineering consultants
showed that the entire sequence of sediment layers is folded and they concluded that this
folding is evidence for an active fault beneath the site, and the fault is either the Portland Hills
Fault, or a closely related structure'".
Grant Butte and Damascus - Tickle Creek Fault Zones
•
The Grant Butte and Damascus - Tickle Creek Fault Zones are located approximately 18• r lfe9 •
(29 km) east of the site. This zone consists of several relatively short nortl1- northwest, •
northwest, and northeast trending faults along a 10 %- mile -long (17 km) fault gyre.: The •
• Butte and Damascus Tickle Creek Fault Zones are considered potentially based op • • •
stratagraphic_r_elatinnships showing_raiddle,_angl_Ro _ssibly late Pleistocene activity` • •
• • • •••
• • •
In 1990, Ian Madin mapped an east - northeast trending fault along the molt!: site of 11iotdnt
Scott and Powell Butte. I n 1991, further work in the area identified a sdrles • of randomly • •
oriented faults in an excavation within the Pliocene to Pleistocene Epoch Trduttdale Formblibb • •
gravels on Grant Butte. • • • •
'1 Conforth and Geomatrix Consultants, 1992. Seismic hazard evaluation, Bull Run dam sites near Sandy, Oregon: unpublished
report to City of Portland Bureau of Water Works.
72 Balsillie, J.J. and Benson, G.T., 1971. Evidence for the Portland Hills fault: The Ore Bin, Oregon Dept. of Geology and
Mineral Industries, v 33, p. 109 -118.
13 Wong et al., 2001. The Portland Hills Fault: An Earthquake Generator or Just Another Old Fault? Published by Oregon
Geology. V63, number 2, Spring 2001.
14 Madin and Hemphill - Haley, 2001: The Portland Hills Fault at Rowe Middle School. Oregon Geology V63 p47.
75 Geomatrix Consultants, 1995. Ibid.
7e Madin, 1990 Ibid.
Carlson Geotechnical Page 9 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
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Bolton Fault
The Bolton Fault is a northwest trending fault, with a length of about 6 miles (9 km) in the
subsurface, located approximately 10 miles (16 km) southeast of the site. There is no evidence
that the Bolton Fault has been active since the late Pleistocene; however, the fault is classified
as potentially active because of the limited exposures and uncertainties in the relationships
between local scarps and late Pleistocene flood deposits On this basis, a very low probability
of activity is assigned to the Bolton Fault.
Yamhill- Sherwood Structural Zone
The Yamhill- Sherwood Structural Zone is a northeast trending structural zone located
approximately 3 miles (5 km) southeast of the site, which includes the Yamhill River Fault and
the Sherwood Fault. Based on a proprietary seismic profile, Yeats and others suggested
these faults are part of a structural zone beginning near Sheridan, Oregon and trending along
the northern end of the Amity Hills towards Sherwood, Oregon. Geomatrix Consultants indicate
in their seismic design mapping report completed in 1995 that the Sherwood Fault is inactive,
and the Yamhill River Fault or the Yamhill- Sherwood structural zone is not mentioned;
•
therefore, we consider this fault zone to be inactive.
Mount Angel, Newberg, and Gales Creek Faults
•••• • •
The Newberg Fault is part of a 50 -mile -long zone of discontinuous, northwest- �tfer:ding faults.
The Newberg Fault is located approximately 12 miles (19 km) southwest of a pit,. In • • •
Unruh and others modeled the Mount Angel, Newberg, and Gales Creek Faults as separate • •
•
faults rather than a long, continuous fault zone based on changes in sense•ot dieplaceuent,.
evidence for discontinuities in the subsurface, different deformation histories, and •differenccs•in, • • • • • •
•
geomorphic expression and seismicity. However, since the faults share a common orienfation,% •
and several other studies have indicated that these faults may be 414r1.6f a larder •
interconnected zone of deformation, we have considered these faults as i it1t1P
zone as well. The Mount Angel, Newberg, and Gales Creek Fault Zone is recognized jntjie
subsurface by vertical separation of the Columbia River Basalt, and offset seismic reflectors i 1 •••• •
t7 Geomatrix Consultants, 1995. Ibid.
78 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.
19 Geomatrix Consultants, 1995. ibid.
20 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).
21 Nablek, J., A. Ttrehu, G. Lin, G. Vernon, and J. Orcutt, 1991. Samson; preliminary results fro the onshore broadband array
(abs): Eos, American Geophysical Union, v 72., n. 44, p. 302.
22 Yeats, R.S., Graven, E.P., Werner, K.S., Goldfinger, C., and Popowski, T., 1996. Ibid.
Carlson Geotechnical Page 10 of 32
Tigard Fire Station
Tigard, Oregorl
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CGT Project Number G0602953
January 9, 2007
overlying basin sediments A geologic study conducted for the Scoggins Dam site in the
Tualatin Basin revealed no evidence of deformed geomorphic surfaces along the Gales Creek
or Newberg Faults, and no seismicity has been recorded on these faults In contrast,
geomorphic surfaces that extend across the Mt. Angel Fault are warped such that they are
consistent with uplift on the northeast side of the fault In 1990, a series of small earthquakes
( <M3.5) occurred near the town of Woodburn, and in 1993, an M5.6 earthquake occurred near
the town of Scotts Mills These seismic events are generally attributed to the Mt. Angel
Fault.
The Helvetia Fault
The Helvetia Fault is a north - northwest trending structure located approximately 9 miles (14 km)
northwest of the site. There is no evidence for displacement of late Quaternary deposits along
the fault; however, the most recent age of displacement is poorly constrained Therefore, the
fault is considered potentially active, but with a low probability of activity.
The Beaverton Fault Zone
The Beaverton Fault Zone consists of two northeast trending faults located approximately 6
miles (10 km) northwest of the site. The two faults associated with this zone displace the top of
the Columbia River Basalts as observed in seismic reflection lines and well logs Yeats and
others indicate that the Beaverton Faults displace post - Columbia River 6a sedifiejits;
however, the age and nature of deformation is not known. They also indicate ;hat tlje faults are • •
not exposed at the surface. Unruh evaluated the activity of the Beaverton: faults and . .
concluded that the faults are in active.
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23 Werner, K.S., Nabelek, J., Yeats, R.S., Malone, S., 1992. The Mount Angel fault: implications of seismic-reflection data and
the Woodbum, Oregon, earthquake sequence of August, 1990: Oregon Geology, v. 54, p. 112 -117.
24 Yeats, R.S., Graven, E.P., Werner, K.S., Goldfinger, C., and Popowski, T., 1996. Ibid.
25 Unruh, J.R., Wong, I.G.. Bott, J.D., Silva, W.J., and Lettis, W.R., 1994. Ibid.
2e Unruh, J.R., Wong, I.G., Bott, J.D., Silva, W.J., and Lettis, W.R., 1994. Ibid.
22 Geomatrix Consultants, 1995. Ibid.
28 Werner, K.S., Nabelek, J., Yeats, R.S., Malone, S., 1992. Ibid
29 Geomatrix Consultants, 1995. Ibid.
3° Geomatrix Consultants, 1995. Ibid.
31 Yeats, R.S., Graven, E.P., Werner, K.S., Goldfinger, C., and Popowski, T., 1996. Ibid.
32 Unruh, J.R., Wong, 1.G., Bott, J.D., Silva, W.J., and Lettis, W.R., 1994. Ibid.
Carlson Geotechnical Page 11 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
Other Mapped and Unmapped Crustal Sources
Several other crustal sources, including numerous unnamed inferred faults mapped within a few
miles of the site may be capable of producing damaging earthquakes in the region. However,
due to their distance from the site, non - active classification, their short fault segments, or low
probability of activity, we did not elaborate on these sources for this study.
Several crustally derived seismic events have been recorded in areas where no faults are
mapped. Recent seismic activity near Kelly Point near the confluence of the Willamette and
Columbia Rivers in Portland, Oregon is an example of seismicity that cannot be correlated to a
known fault. This fact is most likely a function of the heavy forestation of western Oregon
preventing the direct observation of faults that may occur in those areas. Additionally, most
faulting within. the Portland area does not _cut the Holocene sediments and is thus difficult to
define. Furthermore, the displacement of the Holocene sediments due to ongoing fault
movement in recent geologic time is minor and difficult to observe. Additional geophysical
studies may define these unmapped sources in the future.
Intra -Slab Source
Earthquakes derived from intra -slab sources occur within the subducting Juan De Fuca Plate
(oceanic) at depths ranging from 20 miles (32 km) to 40 miles (64 km) bgs Approximately
20 miles (32 km) west of the current Oregon coast line is the CSZ where the subducting'iNn '
De Fuca Plate moves eastward (relative to the North American Continent) beneat i the NQa • •
•
American Plate dipping at an angle of 10 to 20 degrees. As the plate moves iai4 ie! away iom
the CSZ, the curvature of the plate increases and causes normal faulting within. the oceanic •
slab in response to the extensional forces of the down dipping plate. The regton•of matimtlitt • •
curvature of the slab is where large intra -slab earthquakes are expected PI. occur, �nd;i9 �• •;
located roughly 30 miles (48 km) below the Oregon Coast Range, approximataly.30 miler148'
km) west of the site. Historically, the seismicity rate within the Juan De Fun Plate beneath
Oregon is very low in northern Oregon and southwest Washington, and extremely law•iri S
southern and central Oregon34•35 •••••• •
•
•
ss Geomatrix Consultants, 1995. Ibid.
30 Geomatrix Consultants, 1995. Ibid.
35 Geomatrix Consultants, 1993. Seismic margin Earthquake For the Trojan Site: Final Unpublished Report For Portland
General Electric Trojan Nuclear Plant, Rainier, Oregon, May 1993.
Carlson Geotechnical Page 12 of 32
Tigard Fire Station
Tigard, Oregon •
CGT Project Number G0602953
January 9, 2007
Cascadia Subduction Zone (CSZ)
The CSZ is a 680 - mile -long (1,088 km) 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
four cm /year Very little seismicity has occurred on the plate interface in historic time, and as
a result, the seismic potential of the Cascadia Subduction Zone is a subject of scientific
controversy. The lack of seismicity may be interpreted as a period of quiescent stress buildup
between large magnitude earthquakes, or characteristic of the long -term behavior of the
subduction zone. A growing body of geologic evidence; however, strongly suggests that
prehistoric subduction zone earthquakes have occurred 37,38,39,40 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 47,42,43,44. The
inferred seismogenic portion of the plate interface is roughly coincident with the
Oregon/Washington coastline and lies approximately 77 miles (123 km) west of the site.
Earthquake Magnitude
Both deterministic and probabilistic methods are generally used to evaluate the seismic hazard
at a specific site. The deterministic method considers the worst -case scenario based on.the • •
maximum credible earthquake (the largest earthquake that could be expectedtot ,cur), a?i is
used for critical facilities like power plants, hospitals, and hazardous substance st�ore8e • • •
facilities. The probabilistic method considers the probability of earthquake ¤ce during • •
the lifetime of a particular facility, and is more appropriate for residential' attd.tromnlerji31, •
•
development. Both methods involve the choice of a design earthquake that is•uZed Jo calcilatp., • • • • •
the intensity of ground motion expected at the site. • • • • • • •
.. •• •
....
• ••••
.
•••• .
.. •
• • • • 38 DeMets, C., Gordon, R.G., Argus, D.F., Stein, S., 1990. Current plate motions: Geophysical Journal International, v. 101, p. • ''
•
425-478.
37 Geomatrix Consultants, 1995. Ibid.
38 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.
38 Carver, G., 1992. Late Cenozoic tectonics of coastal northern California: American Association of Petroleum Geologists -
SEPM Field Trip Guidebook, May, 1992.
40 Peterson, C.D., Darioenzo, M.E., Bums, 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. 99144.
41 Geomatrix Consultants, 1995. ibid.
42 Atwater, B.F., 1992. Ibid.
43 Carver, G., 1992. Ibid.
44 Peterson, C.D , Darioenzo, M.E., Burns, S.F., and Bums, W.K., 1993. !bid
• Carlson Geotechnical Page 13 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
Maximum Credible Earthquake (Deterministic)
The primary means for estimating the maximum credible earthquake that a particular fault could
generate are empirical relationships between earthquake magnitude and fault rupture length
Based on these relationships, the size of historical earthquakes, and the thickness of
seismogenic crust in the Willamette Valley, the maximum earthquake magnitude expected from
crustal source is M6.0 to M6.6 Based on the likely thin nature of the Juan De Fuca Plate, and
comparing the historic seismicity along the CSZ with other margins, Geomatrix Consultants
estimated the maximum magnitude earthquake for intra -slab sources is M7 to M7.5. Similarly,
based on magnitude versus rupture area relationships for subduction zone earthquakes
worldwide, the maximum magnitude of a CSZ earthquake is estimated to be M8.0 to M9.0
Maximum Probable Earthquake (Probabilistic)
Magnitude estimates for the maximum probable earthquake are based largely on the record of
historical earthquakes in the region of interest. Table 1 lists earthquakes with magnitudes
larger than M4.9 that have occurred in Oregon and western Washington since 1873
•
• .... • •
• •
. . .
...•
• •
....
• • . .
•• •
•• ••
• • • ..
• •••• .
•• • .
• • •
•• •• •
••••
• •
• • •••• •
•••• .
•• •
• • •
•• • • •
45 Bonilla, M.G., R. K Mark, and J.J. Lienkaemper, 1984, Statistical relations among earthquake magnitude, surface rupture
length, and surface fault displacement: Bulletin of the Seismological Society of America, V. 74, p. 2379 -2411.
49 Geomatrix Consultants, 1995. Ibid.
47 Geomatrix Consultants, 1995. Ibid.
" Geomatrix Consultants, 1995. Ibid.
49 Wong et al, 2000. Wong, I. Silva, W. Bolt, J., Wright, D., Thomas, P., G
9 9 9 Gregor. N., Li, S., Mabey, M., Sojourner, A., Wang, Y.
IMS -15. Earthquake Scenario and Probabilistic Ground Shaking Maps for the Portland, Oregon, Metropolitan area. Portland
hill Fault M6.8 Earthquake, Peak Horizontal Acceleration at the Ground Surface.
Carlson Geotechnical Page 14 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
Table 1. Historical Earthquakes in Oregon and Western Washington with
Magnitudes Greater than M4.9
> : o dified
fJalg:r ; Magnitude M�itintiltji -. .M Location • M0001li iijtensi
1877 M5.25* VII Portland, OR
1892 M5.0* VI Portland, OR
1936 M6.1 VII+ Milton -
Freewater, OR
Vancouver, WA
1962 M5.5 VII - Portland, OR
1968 M5.0 V Adel, OR
• 1993 M5.6 VII Scotts Mills,
OR
Klamath Falls,
1993 M6.0 VII -VIII OR
Near Olympia,
2001 M6.8 VII -VIII WA
*Magnitude estimated from Modified Mercalli Intensity Scale. ••.•
• •
••••
•
Based on the historical record and crustal faulting models of the Willamette iallay regioa*3ae
maximum probable earthquake for crustal sources in the vicinity of the subject Site is estimated ''
to be M5.75 Similarly, the maximum probable earthquake for an intra- slabsat rce cjr • •
CSZ is estimated to be M7.5 to M7.7. • • • • • •
• • • •
•• • •
Seismic Shaking •
• •
A standard quantitative method of describing ground motion associated with propagai!igg
•
seismic waves is to specify peak ground accelerations (PGAs) in bedrock. PGAs are average • ••••
•
values based on empirical attenuation relationships of seismic wave energy with distance from
the causative fault. PGAs are expressed as a fraction of the acceleration of gravity (i.e., a
vertical PGA of >1.0 g would throw objects into the air). Table 2 shows the estimated PGAs at
the subject site for the maximum credible events (deterministic) on the listed faults based on
•
5° Geomatrix Consultants, 1995. Ibid.
Carlson Geotechnical Page 15 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
attenuation relationships developed by Geomatrix Consultants numerical models by Cohee et
al. and Youngs et al. and recent ground shaking maps for the Portland Hills Fault
Table 2. Estimated Peak Ground Accelerations at "Rock Sites"
Resulting from Maximum Credible Events on Known Faults
• I�Ib E 9i:`entr'al. Est i`
• M. ? ;:M:agnitude'�Mw): p sta�iice;'(lkin .i rourtd.Accel
Portland Hills Fault Zone 6.6 9.6 0.33 g
Bolton Fault 6.6 16 0.22 g
Mount Angel, Newberg, and 6.6 19 0.17 g
Gales Creek Faults
Grant Butte and Damascus- 6.6 29 0.12 g
Tickle Creek Fault Zones
Cascadia Subduction Zone 8.5 77 0.10 g
Intra -Slab 7.5 30 0.23 g
A recent study commissioned by the Oregon Department of Transportation evaluated all known
earthquake sources in Oregon, and formulated probabilistic assessments of expected seismic •
• shaking; based on maximum probable earthquake magnitudes Table 3 presents thts•peak
bedrock accelerations expected at the subject site (5% dampening), estj'nated recurr@r • •
••••
intervals, and the corresponding probability of occurrence in the next 50 years. • • •
••••
• • •
•• •
• • •
•• ••
• • • •••
• • • •• .
•• • •
• • •
•• •• •
....
• .
• • •••• •
•••• •
•• • •
• • •
•• • • •
51 Geomatrix Consultants, 1995. Ibid.
52 Cohee, B.P., Somerville, P.G., and Abrahamson, N.A., 1991, Simulated ground motions for hypothetical Mw = 8 earthquakes
in Washington and Oregon: Bulletin of the Seismological Society of America, v. 81, p. 28 -56.
53 Youngs, R. R., S.-J. Chiou, W.L. Silva, and J. R. Humphery, 1993, Strong ground motion attenuation relationships for
subduction zone earthquakes based on empirical data and numerical modeling (abs.): Seismological Research Letters, v. 64
p.18.
54 Wong et al., 2001. Ibid.
55 Geomatrix Consultants, 1995. Ibid
Carlson Geotechnical Page 16 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953 •
January 9, 2007
Table 3. Expected Ground Shaking at "Rock Sites" from Crustal,
Plate- Interface, and Intra -slab Earthquake Sources
• Modified Mercalli- Peak • • • Chance of •
Jrjteiisity ACceleratiori . Recurrence ir►t ryaF ,.. Occurreilcein-the
.. , %.grayity) ` ; ° _ - ;Next, 5p YNars . .
VII+ 0.20 g 500 years 10%
•
VIII 0.28 g 1,000 years 5%
VIII+ 0.38 g 2,500 years 2%
Another method of describing the intensity of ground shaking associated with an earthquake is
the Modified Mercalli Intensity Scale. This scale is a subjective measure of the affects
experienced by people, man -made structures, and the earth surface. The two largest historical
earthquakes in northwestern Oregon, the 1962 M5.5 earthquake near Portland, and the 1993
M5.6 earthquake in Scott Mills, generated maximum Modified Mercalli intensities of VII The
Modified Mercalli intensities predicted for the subject site due to occurrence of maximum
probable events is shown in Table 3. An abridged portion of the Modified Mercalli intensity
scale, after Bott is presented in Table 4.
Table 4. Abridged Portion of the Modified Mercalli Intensity Scale
General alarm and everyone runs outdoors. Damage is negligible in buildings of good design
YII and construction; slight to moderate in well -built ordinary structures; considerable in p56119 •
built or badly designed structures; some chimneys broken. Plaster antl•SdMO stuccdldll'
g1 Loosened brickwork and roof tiles shake down. Heavy furniture overturrjs. Strgam andttit I • • •
banks cave. ••••
• •
• zf % ' General fright and alarm approaching panic.. Damage is slight in specially designed structures; • • •
considerable in ordinary substantial buildings with partial collapse; greet in poorly..buili• • • structures. Panel walls thrown out of frame structures. Fall of chimneys, cel w ns, and walls. • • ••
. (O:Z- ;to!•0 :30.g)'., Heavy furniture is overturned. Branches and tree trunks break off. Liqualti, sand andtujd; •
erupts on ground surface. •• ' •
:I General panic. Damage is considerable in specially designed structures; euta tlQsigned tarn •
structures thrown out of plumb; great in substantial buildings, with partial tS1106. •
(O.5Q=to',Qi55 g)', shifted off foundations. Conspicuous ground cracking. Underground pipes broken. • • • • •
• • •
•• • •
•
58 Wong, I. Silva, W. Bott, J., Wright, D., Thomas. P., Gregor. N., Li, S., Mabey, M., Sojourner, A., Wang, Y. 2000. Ibid.
57 Bott, J.D.J., and Wong, I.G., 1993. Historical earthquakes in and around Portland, Oregon: Oregon Geology, v. 55, no 5, p.
116 -122.
Carlson Geotechnical Page 17 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
Site Surface Conditions
The site consisted of one tax lot totaling approximately 3.27 acres. A single - family residence
and barn occupied the site (Figure 3, Photographs 1 and 3). The site typically descended
toward the northwest at gradients up to approximately 10 horizontal to 1 vertical (10H:1V). The
slope gradient steepened up to 2H:1V near the northwestern property line. Total relief across
the site was on the order of 8 feet. The majority of the site was covered with cut grasses and
scattered trees (Figure 3, Photographs 2 and 4).
Site Subsurface Conditions
Field Exploration
Three hollow- stem -auger borings (B -1 through B -3) were advanced at the site on November 27,
2006, to depths of up to 511/2 feet bgs using a Mobile B -53, truck - mounted, hollow- stem -auger
drill rig provided and operated by Subsurface Technologies of North Plains, Oregon. Boring
B -1 was advanced to a depth of about 51% feet bgs within the proposed building footprint, and
borings B -2 and B -3 were advanced to depths of approximately 21% feet bgs within the parking
lot areas. In addition, one Cone Penetrometer Test (CPT) was performed at the site on
November 29, 2006. The CPT test (CPT -1) was advanced to a depth of about 71 feet bgs.
The approximate boring and CPT test locations are shown on the attached Site Plan, Figure 2.
The borings and CPT were located in the field using approximate measurements from exist] .19 • •
site features shown on the Site Plan. A member of CGT's staff'logged the soilsiobs4rved Whim'
the borings in general accordance with the Unified Soil Classification Systgm (l1SCS), $AQ• • •
collected representative samples of the materials encountered. CGT has provided • in
explanation of the USCS on the attached Soil Classification Criteria and Termiifc. 8 y, Figure 4,
Our laboratory staff visually examined all samples returned to our laboratory in a der to refine ..• '
the field classifications. • •�• •
• • .
Standard Penetration Tests (SPTs) were conducted within the borings at 21/2rfoot4ntervaf?
depths of 15 feet bgs, and then at 5 -foot intervals to the termination depths of the 1 brings. , • •
SPT is performed by driving a 2 -inch, outside - diameter, split -spoon sampler into • the ' • • •••
•
undisturbed formation located at the bottom of the advanced boring with repeated blows of a
140 - pound, automatic hammer falling a vertical distance of 30 inches. The number of blows. N-
Value, required to drive the sampler one foot, the last 12 inches of an 18 -inch sample interval,
is used to measure the soil consistency (cohesive soil), or relative density (non- cohesive soils)
Carlson Geotechnical Page 18 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
It should be noted that automatic hammers generally produce lower SPT values than those
obtained using a traditional safety hammer. Studies have generally indicated that penetration
resistances may vary by a factor of 1% to 2 between the two methods. We have considered
this in our description of soil consistency, and in our evaluation of soil strength and
compressibility.
Logs of the borings are presented on the attached Boring Logs, Figures 5 through 7. The
results of the CPT test are presented on the attached CPT Log, Figure 8. Results of the
laboratory tests are shown on the attached logs.
Subsurface Materials
The upper approximately 1 /2-foot of material encountered within the borings consisted of silt
topsoil (OL). The silt topsoil was typically soft, moist, brown, and contained rootlets.
Underlying the silt topsoil in the borings, was native, soft to medium stiff, moist to wet, brown,
sandy silt (ML). The sandy silt was encountered to the total depths explored in borings B -2 and
B -3, 21% feet bgs. Within boring B -1, the sandy silt was underlain by lean clay (CL) at a depth
of 48 feet bgs. The lean clay was medium stiff, wet, grey /brown, and was encountered to the
total depth explored, 51 feet bgs, within boring B -1.
The subsurface materials and the results of our laboratory testing are described in more detail
on the attached Boring Logs, Figures 5 through 7. •••• • • •
••••
•
Groundwater • • •
Groundwater was encountered in the borings advanced at the site on Noven1I r 27 2006.A.
•
depths ranging from about 10 to 13 feet bgs. A review of water well logs publishedbythe Orgg2g. • • • • • •
•
Department of Water Resources for wells located within about 1 /2 -mile of the §Re ndicated•tt at: •
groundwater was encountered by others at similar depths. It should be noted s lat 4 oundwatbr •
levels are relative to the ground surface and, due to local topography, the leverlrted t?rlfbe•
logs are considered generally indicative of local groundwater levels and may riot'1eflect §sKual.
•
groundwater levels at the site. We anticipate that groundwater levels will fluctuate due' t6 • ••••
seasonal and annual variations in precipitation, changes in site utilization, or other factors. In
addition, the onsite, native, sandy silt (ML) is conducive to low infiltration rates and the formation
of perched groundwater tables.
58 ORWD, 2006. Water well logs obtained from the Oregon Water Resources Department web site, http: //www.wrd.state or.us/
Carlson Geotechnical Page 19 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
•
Liquefaction
Discussion
In general, liquefaction occurs when deposits of loose, saturated soils, generally sands, and
sand -silt mixtures, are subjected to strong earthquake shaking. If these deposits cannot drain
rapidly, there will be an increase in the pore water pressure. With increasing oscillation, the
pore water pressure can increase to the value of the overburden pressure. The shear strength
of a cohesionless soil is directly proportional to the effective stress, which is equal to the
difference between the overburden pressure and the pore water pressure. When the pore
water pressure increases to the value of the overburden pressure, the shear strength of the soil
reduces to zero, and the soil deposit turns into a liquefied state.
The following parameters are generally used to designate non - liquefiable, fine- grained soils:
• Fines content (percent passing the U.S. Standard No. 200 Sieve) greater than
80 percent.
• Clay content (particle size less than 0.005 mm) exceeding 20 percent.
• Liquid limit greater than 35 percent.
• Water content less than 90 percent of the liquid limit.
Analysis • • • •
•
•
•••• •
• •
We performed a liquefaction analysis for the site soils based on data obtained WmlPT- 1 • •
the CivilTech, Inc., software program LiquefyProm'. Our analysis included thErcillowing. inpwt •
values: static groundwater level at 12 feet bgs, a design level earthquake of,114Z. and a' peak •• ' • •'
ground acceleration (PGA) of 0.33g. The analysis indicated that liquefaction settlement at thu;t • �
during a design level earthquake near the site may be on the order of approiiVafely 3 inches. •
This estimated liquefaction settlement is equal to the anticipated differential settlement at the tltb7.
••••••
.• .
• • .
•• • •
CONCLUSIONS ••••
Seismic Hazards
Based on the available literature, the Portland Hills Fault Zone, the Mount Angel, Newberg, and
Gales Creek Faults, the Bolton Fault, and the Damascus - Tickle Creek Fault Zone are
potentially active Any of these faults could produce a damaging earthquake at the site. •
Several unnamed faults are mapped in the area, but none of these faults are considered active.
59 Geomatrix Consultants, 1995. Ibid.
Carlson Geotechnical Page 20 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
Liquefaction Induced Settlement
Based on our analysis, settlement due to liquefaction during a design level earthquake near the
site may be on the order of approximately 3 inches. The structural engineer should design the
foundation system to withstand up to 3 inches of total and differential settlement resulting from
liquefaction.
Lateral Spreading
A shallow creek runs along the northern property boundary, which could be a free face toward
which lateral spreading could occur. Given the distance of the face to the location of the
proposed fire station, damage to the fire station from seismically- induced lateral spreading is
considered low.
Landslidinq
Slopes in the northwestern corner of the site had gradients on the order of 2H:1 V, therefore, there
is a potential for seismically induced landsliding or slope instability to occur based on the potential
for liquefaction and lateral spreading. These slopes are on the order of 20 feet high, and are
located approximately 100 feet from the northern edge of the proposed fire station. Therefore, the
potential for seismically - induced landsliding impacting the proposed fire station is considered low.
• • •
•
Tsunami or Seiche Inundation • • • • • •
• •
..••
The site is located several miles away from any significant body of water; theretdr the potential • •
for tsunami or seiche inundation of the site is considered negligible. • •
•
• • • ••
• • • • • •
•• • •
Fault Displacement and Subsidence •
•• •• •
•••• •
• As described above, several faults in the area are considered to be potentialr•asti3e; however, • •
since no faults are known to exist on the site, the potential for fault displacement is negligible.' •
Seismic Shaking
The IBC Design Criteria provided within Table 5 of the Seismic Design Section of this report
indicates a short period amplification factor (F of 1.08, which translates to a slight amplification
of the short period acceleration (Ss) of 1.06g for Site Class D — Stiff Soil. Also within Table 5, a
long period amplification factor (F of 1.65 was indicated, which translates to a moderate
amplification of the long period acceleration (S of 0.37g for Site Class D. Site Class D was
used at the site based on the soft to medium stiff, sandy silt (ML) encountered within the
borings. Based on this information, the site is considered to have a low hazard for amplification
Carlson Geotechnical Page 21 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
of seismic shaking at the site for short periods and moderate for long periods. These findings
are in general agreement with seismic maps of the area
General
Based on the results of our field explorations and analyses, the site can be developed as
proposed in the Project Information section of this report, provided the following
recommendations are incorporated into the design and development.
The silt topsoil (OL) should not be relied upon for foundation, floor slab, or pavement support.
Excavations for the building will expose native, soft to medium stiff, sandy silt (ML). CGT
performed settlement calculations using Schmertmann's Method for the proposed building.
Based on the results of our settlement calculations, we recommend over - excavating the native,
sandy silt (ML) in proposed footing locations, and backfilling the resulting excavations with
imported granular structural fill: All over - excavations should be a minimum of 16 inches below
foundation bearing elevations and constructed a minimum of 6 inches wider for every foot of
over - excavation. The native, soft to medium stiff, sandy silt was encountered at depths of
approximately % -foot bgs within our borings.
The results of our liquefaction analysis indicated that settlement due to liquefaction during a
design level earthquake near the site may be on the order of approximately 3 inches. The
structural engineer should design the foundation system to withstand up to 3 inches of toter911ti. • •
••••
differential settlement due to soil liquefaction. • • • • • • •
• • • •
••••
The following paragraphs present specific geotechnical recommendations foc •design aPid • • •
construction of the proposed fire station. • • •
• • :•:', •
•• • •
RECOMMENDATIONS • • •
....
• •
The recommendations presented in this report are based on the information•pro ded to us,•
results of the field investigation, laboratory data, and professional judgment. CGT.aaa•
observed only a small portion of the pertinent soil and groundwater conditions. The
recommendations are based on the assumptions that the soil conditions do not deviate
appreciably from those found during the field investigation. If the design or location of the
proposed development changes, or if variations or undesirable geotechnical conditions are
encountered during site development, CGT should be consulted for further recommendations.
e° Mabey, M.A., Madin, I.P., Youd, T.L., Jones, C F F. 1993, Ibid.
Carlson Geotechnical Page 22 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007 •
Site Preparation
• Surface vegetation and silt topsoil (OL) should be removed from proposed building, structural
fill, and pavement locations, and for a 5- foot - margin around such locations. Based on the
results of our field explorations, the depth of surface vegetation and silt topsoil stripping within
proposed building, structural fill, and pavement locations will be on the order of approximately
% -foot. A geotechnical representative from CGT should provide recommendations for actual
stripping depths based on observations during site stripping. Stripped surface vegetation and
silt topsoil should be transported off -site for disposal, or stockpiled for later use in landscaped
areas. Grubbing of trees should include the removal of the root mass, and roots greater than
Winch in diameter. Grubbed material should be transported off -site for disposal. Existing
footings, foundation walls, slabs -on- grade, and pavements associated with structures identified
for demolition (the residence and barn), or previous structures, should be completely removed
and disposed off-site.
After site preparation as recommended above, a representative from CGT should observe a
proof -roll of the exposed subgrade soils in order to identify areas of excessive yielding. If areas
of soft soil or excessive yielding are identified, the affected material should be overexcavated to
firm, stable subgrade, and replaced with compacted materials as recommended for structural
fill.
Silt fences, hay bales, buffer zones of natural growth, sedimentation ponds, and granular hat.& • •
••••
roads should be used as required to reduce sediment transport during corrstructiorh q
acceptable levels. Measures to reduce erosion should be implemented in genel'alaccordar#ce •
with State of Oregon Administrative Rules 340-41 -006 and 340 -41 -455, and. City of Tigard •. •
regulations regarding erosion control. •• •
Wet Weather Considerations
• •
••••
The on -site, native, sandy silt (ML) has a high percentage of fines and is hiPq's'dsceptTble•td •
disturbance during wet weather. Trafficability of this soil may be difficult, and sigrv'fieant •
damage to subgrade soils could occur if earthwork is undertaken without proper precautions at ' •••• •
times when the exposed soils are more than a few percentage points above optimum moisture
content. Care should be taken to minimize disturbance of this soil, which may be disturbed by
repeated or heavy construction traffic, or by vibratory compaction.
For construction that occurs during the wet season, site preparation activities may need to be
accomplished using track - mounted equipment, loading removed material into trucks supported
on granular haul roads, or other methods to limit soil disturbance. A qualified geotechnical
engineer should evaluate the subgrade during excavation by probing rather than proofrolling.
Soils that have been disturbed during site preparation activities, or soft or loose areas identified
Carlson Geotechnical Page 23 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
during probing, should be overexcavated to firm, stable subgrade, and replaced with structural
fill.
Haul roads subjected to repeated or heavy construction traffic will require a minimum of
18 inches of imported granular material. Twelve inches of imported granular material should be
sufficient for light staging areas. The imported granular material should consist of crushed rock
that is well - graded between coarse and fine, contains no organic matter, debris, or particles
larger than 4 inches, and has less than 5 percent material by weight passing the U.S. Standard
No. 200 Sieve. The imported granular material should be placed in one lift over the prepared,
undisturbed subgrade, and compacted using a smooth -drum, non - vibratory roller.
CGT recommends that a geotextile filter fabric be placed as a barrier between the subgrade
and imported fill in areas of repeated construction traffic. The geotextile filter fabric should
have a minimum Mullen burst strength of 250 pounds per square inch for puncture resistance,
and an apparent opening size (AOS) between the U.S. Standard No. 70 and No. 100 Sieves.
Structural Fill
Any fill placed within 5 feet of the limits of the proposed building and pavement locations should
be treated as structural fill.
On -Site Materials •••• • •
II • •
••••
The silt topsoil (OL) is not suitable for reuse as structural fill. Excavated silt Aopsoi5 shou•-..
ld.Be'
• •..• •
removed from the site or stockpiled for later use in landscaped areas. • •
••.. •
• • • • •
Use of the on -site, native, sandy silt (ML) as structural fill may be difficult beeeeise this soil is • • • • • •
•
sensitive to small changes in moisture content and is difficult, if not impossibld,'fd adegiiatdly: •
compact during wet weather. If this soil is reused as fill, it should be free of prghic matter, •
debris, and particles larger than 1 inches. CGT anticipates that the moistu=avent v'li •
soil will be higher than the optimum moisture content for satisfactory compaction, except
perhaps during the driest time of the year. Therefore, moisture conditioning (drying) should'bd • '•.••'
anticipated in order to achieve adequate compaction. When used as structural fill, this soil
should be placed in lifts with a maximum loose thickness of about 8 inches, and compacted to
not less than 92 percent of the materials maximum dry density, as determined in general
accordance with ASTM D1557.
If this soil cannot be properly moisture - conditioned, CGT recommends using imported granular
structural fill for fill.
•
Carlson Geotechnical Page 24 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
•
January 9, 2007
` L v
Imported Granular Structural Fill
Imported granular structural fill should consist of angular pit or quarry run rock, crushed rock, or
crushed gravel that is fairly well graded between coarse and fine particle sizes. The granular fill
should contain no organic matter, debris, or particles larger than 1% inches, and have less than
5 percent material passing the U.S. Standard No. 200 Sieve. The percentage of fines can be
increased to 12 percent of the material passing the U.S. Standard No. 200 Sieve if placed
during dry weather, and provided the fill material is moisture - conditioned, as necessary, for
proper compaction. Granular fill material should be placed in lifts with a maximum thickness of
12 inches, and compacted to not less than 95 percent of the materials maximum dry density, as
determined in general accordance with ASTM D1557.
Shallow Foundations
Based on the results of our settlement calculations, we recommend over - excavating the native,
soft to medium stiff, sandy silt (ML) in proposed footing locations, and backfilling the resulting
excavations with imported granular structural fill. All over - excavations should be a minimum of
16 inches below foundation' bearing elevations and constructed a minimum of 6 inches wider for
every foot of over - excavation. The native, soft to medium stiff, sandy silt was encountered at
depths of approximately 'A -foot bgs within our borings.
•
If soft or otherwise unsuitable soils are encountered, they should be overexcavatecl.as . .
recommended by CGT. The resulting overexcavation should be brought baelt•ti grade•witfi
imported granular structural fill. All granular pads for footings should be const� �teda mi irr gm ••
of 6 inches wider on each side of the footing for every vertical foot of overexcaVatiorf. ••
•
• • • • •
•• •
CGT recommends that all individual spread footings have a minimum width of :241nches. Nit ••••••
the base of the footings be founded at least 18 inches below the lowesf'id'acent Made: •.
Continuous wall footings should have a minimum width of 15 inches for p1.tb two -st8ry
••••
structures, and be founded a minimum of 18 inches below the lowest;stdja ent ggadg,
Excavations near footings should not extend within a 1H:1V plane projected our and dow 4fr,
the outside, bottom edge of the footings. '• • •••••
•
Bearing Pressure and Settlement
Footings founded as recommended should be proportioned for a maximum allowable soil
bearing pressure of 2,000 psf. This bearing pressure is a net bearing pressure, and applies to
the total of dead and long -term live loads, and may be increased by one -third when considering
seismic or wind loads.
Carlson Geotechnical Page 25 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
For the recommended design bearing pressure, total settlement of footings is anticipated to be
less than 1 inch. Differential settlements between adjacent load bearing walls and columns
should not exceed 1 A -inch.
The results of our liquefaction analysis indicated that settlement due to liquefaction during . a
design level earthquake near the site may be on the order of approximately 3 inches. The
structural engineer should design the foundation system to withstand up to 3 inches of total and
differential settlement due to soil liquefaction.
Lateral Capacity
CGT recommends using a passive earth pressure of 350 pounds per cubic foot (pcf) for design
for footings confined by imported granular structural fill that is properly placed and compacted
during construction. The recommended earth pressure was computed using a factor of safety
of 1'/2, which is appropriate due to the amount of movement required to develop full passive
resistance.
In order to develop these capacities, concrete must be poured neat in excavations, or footing
excavations must be backfilled with compacted structural fill, the adjacent grade must be level,
and the static groundwater level must remain below the base of the footings throughout the
year. Adjacent floor slabs, pavements, or the upper 12- inch -depth of adjacent, unpaved areas
should not be considered when calculating passive resistance. •••• • • •
••••
•
An ultimate coefficient of friction equal to 0.50 may be used when calculating resistancE t6 •'
sliding for footings founded as recommended. • •
•
•••• •
•. • • •
•• •
Drainage ..
CGT recommends placing foundation drains at the base elevations of th2•tO0tangs on the •
outside of the footings. Foundation drains should consist of a 4- inch -diar tpi perfQratetl,
flexible, PVC drainpipe wrapped with a geotextile filter fabric. The drains shoudd.6e bacrc{fl d • •
with a minimum of 2- cubic -foot per lineal foot of open graded drain rock, which shoLld
encased in a geotextile filter fabric in order to provide separation from the surrounding fine -
grained soils. CGT should be contacted to observe the drain prior to backfilling.
•
Carlson Geotechnical Page 26 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
•
Floor Slabs
•
Satisfactory subgrade support for floor slabs constructed on grade, supporting up to 150 psf
area loading, can be obtained from the native, soft to medium stiff, sandy silt (ML), or on
structural fill that is properly placed and compacted on this material during construction. The
native, soft to medium stiff, sandy silt was encountered at depths of approximately Y2 -foot bgs
within our borings. If soft or otherwise unsuitable soils are encountered, they should be
overexcavated as recommended by the CGT geotechnical engineer. The resulting
overexcavation should be brought back to grade with granular structural fill.
A minimum 6- inch -thick layer of'/- inch - minus, crushed rock base, compacted to not less than
95 percent of the materials maximum dry density, as determined in general accordance with
ASTM D1557, should be placed over the prepared subgrade to provide a more uniform surface
for placing concrete, and supporting the slab. The surface of the base rock should be choked
with sand just prior to concrete placement. Choking the base rock surface reduces the lateral
restraint on the bottom of the concrete during curing.
Floor slabs constructed as recommended will likely settle less than Y2 -inch. CGT recommends
that slabs be jointed around columns and walls to permit slabs and foundations to settle
differentially.
Due to the presence of native, sandy silt (ML) near the surface of the site, liquid moisturgAnd • •
moisture vapor should be expected at the subgrade surface. A capillary break, oonsisting•o•af
least 6 inches of crushed rock base having less than 5 percent of the material Passing the I;l'S'
Standard No. 200 Sieve, typically provides protection against liquid moisture' Wh2re moisture • •
•
vapor emission through the slab must be minimized, e.g. impervious floor cove] ig9, storpgmt
moisture sensitive materials directly on the slab surface, etc., a vapor retardippmembrane or ••••••
vapor barrier below the slab should be considered. Factors such W•Cost, Maeda: •
considerations for construction, floor coverings, and end use suggest J t. jhe decisiron •
regarding a vapor retarding membrane or vapor barrier be made by the architeot•aPid owner; ; ;•
•••• •
.. . • If a vapor retarder or vapor barrier is placed below the slab, its location should be bas 2t? dh ••••••
current American Concrete Institute (ACI) guidelines, ACI 302 Guide for Concrete Floor and
Slab Construction. In some cases, this indicates placement of concrete directly on the vapor
retarder or barrier. Please note that the placement of concrete directly on impervious
membranes increases the risk of plastic shrinkage cracking and slab curling in the concrete.
Construction practices to reduce or eliminate such risk, as described in ACI 302 should be
•
employed during concrete placement.
Carlson Geotechnical Page 27 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
Pavement Subgrades
• Generally speaking, satisfactory subgrade support for pavements constructed on grade can be
obtained from the native, soft to medium stiff, sandy silt (ML), or on structural fill that is properly
placed and compacted on this material during construction. The native, soft to medium stiff,
sandy silt was encountered at depths of approximately 'A -foot bgs within our borings. If soft or
otherwise unsuitable soils are encountered, they should be overexcavated as recommended by
CGT. The resulting overexcavation should be brought back to grade with imported granular
structural fill.
The project civil engineer should provide the design pavement sections and specific
recommendations for pavement subgrade preparation.
Additional Drainage Considerations
CGT recommends that subsurface drains be connected to the nearest storm drain or other
suitable discharge point. CGT also recommends that paved surfaces and ground near or
adjacent to the building be sloped to drain away from the building. Surface water from
pavements and open spaces should be collected and routed to a suitable discharge point.
Runoff from roof and pavement areas should not be directed into the foundation drain system.
Utility Trenches
••••
Utility Trench Excavation •
••••
Trench cuts should stand near vertical to depths of approximately 4 feet in tliQ soft. to • • •
medium stiff, sandy silt (ML), provided no groundwater seepage is observed i he sidew $Ie,:It • •
seepage is encountered that undermines the stability of the trench, or caving ldf tYb sidewalls.is • • • • •
observed during excavation, the sidewalls should be flattened or shored. • • • •
••••
If surface water or groundwater is encountered during development oi: • tfib • 'site, tcei I
dewatering may be required to maintain dry working conditions in utility excavations. Purtiprlg •
from sumps located within the trench will likely be effective in removing water resulting from • ••••
•
seepage. If groundwater is present at the base of utility excavations, CGT recommends placing
trench stabilization material at the base of the excavations. Trench stabilization material should
consist of 1 -foot of well - graded gravel, crushed gravel, or crushed rock with a maximum particle
size of 4 inches, and less than 5 percent material passing the U.S. Standard No. 4 Sieve. The
material should be free of organic matter and other deleterious material, and should be placed
in one lift and compacted until well- keyed.
Carlson Geotechnical Page 28 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
While CGT has described certain approaches to the trench excavation, it is the contractor's
responsibility to select the excavation and dewatering methods, to monitor the trench
excavations for safety, and to provide any shoring required to protect personnel and adjacent
improvements. All trench excavations should be developed and monitored in accordance with
applicable OSHA and state regulations.
Trench Backfill Material
Trench backfill material for the utility pipe base and pipe zone should consist of well - graded
granular material containing no organic matter or debris, have a maximum particle size of %-
inch: and have less than 8 percent material passing the U.S. Standard No. 200 Sieve.
Backfill for the pipe base and within the pipe zone should be placed in maximum 12- inch -thick
lifts, and compacted to not less than 90 percent of the materials maximum dry density, as
determined in general accordance with ASTM D1557, or as recommended by the pipe
manufacturer. Backfill above the pipe zone should be placed in maximum 12 -inch -thick lifts,
and compacted to not less than 92 percent of the materials maximum dry density, as
determined in general accordance with ASTM D1557. Trench backfill located within 2 feet of
finished subgrade elevation should be placed in maximum 12- inch -thick lifts, and compacted to
not less than 95 percent of the materials maximum dry density, as determined in general
accordance with ASTM D1557.
.... . .
Seismic Design •
Based on the results of our subsurface explorations and analyses, the folloWiiinhternMfiWnal
Building Code (IBC) design criteria were computed using the 2003 IBC: .
.... •
• ••••
••••
.. .
• • .
•• • . .
••••
Carlson Geotechnical Page 29 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
Table 5. IBC Design Criteria
IBG Co!effi "cien V ue 1,:.,. ;.y'
Site Class D Table 1615.1.1
S 1.06 Figure 1615(1)
F 1.08 Table 1615.1.2(1)
S 0.37 Figure 1615(2)
F 1.65 Table 1615.1.2(2)
• S 1.14 Equation 16 -38
• Sun 0.61 Equation 16 -39
S 0.76 Equation 16-40
• S 0.41 Equation 16 -41
Category* III Table 1604.5
Seismic Use Group ll Paragraphs 1616.2.1,
1616.2.2, or 1616.2.3
Seismic Design D Tables 1616.3(1), and
Category 1616.3(2)
*If this is not correct, please inform us in writing so that changes• to •odr • •. • • •
recommendations can be made, if warranted. • • • • • •
• •
• • •
•••• •
OBSERVATION OF CONSTRUCTION • •• • • • •
•• •
• •
•
•• ••
• We recommend that CGT be retained to review final plans and specifications` tittr to sublyitta3 ••
of the plans to Washington County. This review will allow us to examine 115rAOcuments to •
check that the intent of our recommendations was incorporated into prooeot. piannirxi arSd
design. •••• .� • •
• • •
•• • •
••••
Satisfactory pavement and earthwork performance depends to a large degree on the quality of
construction. Sufficient observation of the contractor's activities is a key part of determining
that the work is completed in accordance with the construction drawings and specifications.
Subsurface conditions observed during construction should be compared. with those
encountered during subsurface explorations, and recognition of changed conditions often
requires experience. CGT recommends that qualified personnel visit the site with sufficient
frequency to detect whether subsurface conditions change significantly from those observed to
date and anticipated in this report.
Carlson Geotechnical Page 30 of 32
•
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
CGT recommends that site stripping, rough grading, foundation, floor slab, and pavement
subgrades, and placement of engineered fill are observed by the project geotechnical engineer
or their representative. Because observation is typically performed on an on -call basis, CGT
recommends that the earthwork contractor be held contractually responsible for scheduling
observation.
LIMITATIONS
CGT has prepared this report for use by the owner /developer and other members of the design
and construction team for the proposed development. The opinions and recommendations
contained within this report are not intended to be, nor should they be construed as a warranty
of subsurface conditions, but are forwarded to assist in the planning and design process.
CGT has made observations based on our explorations that indicate the soil conditions at only
those specific locations and only to the depths penetrated. These observations do not
necessarily reflect soil types, strata thickness, or water level variations that may exist between
explorations. If subsurface conditions vary from those encountered in our site exploration, CGT
should be alerted to the change in conditions so that we may provide additional geotechnical
recommendations, if necessary. Observation by experienced geotechnical personnel should be
considered an integral part of the construction process.
•
This report has been issued with the understanding that it is the ressonsilaility of'flfa •
owner /developer to ensure that the project designers and contractors implement • GArg • •
•
recommendations. When the design has been finalized, CGT recommends tlir•if design: end
specifications be reviewed by our firm • to see that our recommendations have tteer� interprefed • • •
and implemented as intended. If design changes are made, CGT requests thdrw2 be reltfiftdd • •
to review our conclusions and recommendations and to provide a writtep,7ypdificatjonm •
verification. '
• • • •
The scope of our services does not include services related to construction ssfet,X precautit)t%%, ••
and our recommendations are not intended to direct the contractor's methods, techregmee •
sequences, or procedures, except as specifically described in our report for consideration in ""
design.
Geotechnical engineering and the geologic sciences are characterized by a certain degree of
uncertainty. Professional judgments presented in this report are based partly on our
understanding of the proposed construction, familiarity with similar projects in the area, and on
general experience. Within the limitations of scope, schedule, and budget, our services have
been executed in accordance with the generally accepted practices in this area at the time this
report was prepared; no warranty, expressed or implied, are made. This report is subject to
review and should not be relied upon after a period of three (3) years.
Carlson Geotechnical Page 31 of 32
Tigard Fire Station
Tigard, Oregon
CGT Project Number G0602953
January 9, 2007
CGT appreciates the opportunity to serve as your geotechnical consultant on this project. Please
contact us if you have any questions.
Sincerely,
CARLSON GEOTECHNICAL ,,4D
� � � � a G 1 N E d (3
ti
0337PE
o :EGO ER 1
R OREGON
✓ 4
°� 73, `q9
• (
%/ 4 , A,
g L jD P. NO
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F .ING CO. EXPIRES: g/ S ot yeis�ft
Ryan T. Houser, CEG David P. Holt, PE
Senior Engineering Geologist Senior Geotechnical Engineer
•.•. • •
• •
••••
Attachments: Site Location, Figure 1
••••
• •
Site Plan, Figure 2 ••••
• •
Site Photographs, Figures 3 .•.° • .
• • • • •
Soil Classification Criteria and Terminology, Figure 4 • • • •
•• ••
Boring Logs, Figures 5 through 7 • • • •• • •
• • • •
CPT Log, Figure 8 °' •
• •
Appendix A: Liquefaction Analysis • • • •
• •
• ••••
•
••••
Doc ID: \ \GEO \public \GEOTECH\PROJECTS\2006 Projects \Tigard Fire Station \Tigard Fire Station Geotech.doc • • • • • •
•• • • •
•
Carlson Geotechnical Page 32 of 32
c r
TIGARD FIRE STATION, TIGARD, OREGON
- SITE LOCATION
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••
Map created with TOPO!Ti° @2000 Wildflower Productions (www.topo.com) Scale 1 Inch = 2,000 feet
USGS 7.5 Minute Topographic Map Series, Beaverton, OR Quadrangle.
Latest revision 1981
Township 2 South, Range 1 West, Section 4 Willamette Meridian 0 2000 4000
• Carlson Geotechnlcal
P.O. Box 23814 CGT Job No. G0602953 FIGURE 1
1 3401.8250 Tigard, Oregon 97281
TIGARD FIRE STATION, TIGARD, OREGON
SITE PLAN
., ,-./ �' V !•:.•
_ o f a� / / - •
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• • •••• •
•• •• •
•• •
• • •
•• • • •
••••
Approximate Scale 1 inch = 80 feet
0 80 160
NOTES: LEGEND
Drawing based on site plan provided by B -1 & Approximate location of hollow- CGT Job No. G0602953
Client, and on observations made stem auger boring.
while on site. Approximate location of Cone
CPT-10 Penetrometer Test. .
G P .. •.y Carlson Geotechnlcal 0 Number and orientation of site
P.O. Box 23814 photographs shown on Figure 3 FIGURE 2
.3-601-8250 Tigard, Oregon 97281 r — Existing structure
' - — to be removed
•
TIGARD FIRE STATION, TIGARD, OREGON
SITE PHOTOGRAPHS
- r� . a
' .� }• ..1 - - --_. ��i,U'hi.PshC ��^�� -a, •. y ':. lr
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�, .:� a; : l >'. l' s i 4 1. t .t.af ! :"�,y , "S { , 1 .- `Y ✓{ a k r
Photograph 1: Existing barn on northern Photograph 2: Northeastern portion of site.
portion of site. Photo looking northwest. Photo looking northeast.
•
� II •
1
• • •••
••
•II••••
• •
r • • •
Photograph 3: Existing residence on southern Photograph 4: Central portion of site in area of
portion of site. Photo looking west. proposed structure. Photo looking northeast.
See Figure 2 for approximate photograph
locations and directions.
P ' • Carlson Geotechnlcal
P.O. Box 23814 CGT Job No. G0602953 FIGURE 3
3-60/4250 Tigard, Oregon 97281
TIGARD FIRE STATION TIGARD, OREGON
SOIL CLASSIFICATION CRITERIA AND TERMINOLOGY
Classification of Terms and Content USCS Grain Size
NAME : MINOR Constituents (12 -50 %); MAJOR Fines <#200 (.075 mm)
Constituents ( >50 %); Slightly (5 -12 %) Sand Fine #200 - #40 (.425 mm)
Relative Density or Consistency Medium #40 - #10 (2 mm)
Color Coarse #10 - #4 (4.75)
Moisture Content Gravel Fine #4 - 0.75 inch
Plasticity Coarse 0.75 inch - 3 inches
Trace Constituents (0 -5 %) Cobbles 3 to 12 inches;
Other: Grain Shape, Approximate gradation,
es
Organics, Cement, Structure, Odor.. scattered <15% est.,
Geologic Name or Formation: (Fill, Willamette Silt, Till, numerous e >15% est.
Alluvium,...) Boulders > 12 inches
ches
Relative Density or Consistency
Granular Material Flne- Grained(cohesive) Materials
SPT SPT Torvane tst Pocket Pen tsf Manual Penetration Test
N -Value Density N -Value Shear Strength Unconfined Consistency
<2 <0.13 >0.25 Very Soft Easy several inches by fist
0 •4 Very Loose 2 - 4 0.13 - 0.25 0.25 - 0.50 Soft Easy several inches by thumb
4 -10 Loose 4 - 8 0.25 - 0.50 0.50 -1.00 Medium Stiff Moderate several Inches by thumb
10 - 30 Medium Dense 8 -15 0.50 -1.00 1.00 - 2.00 Stiff Readily Indented by thumb
30 - 50 Dense 15 - 30 1.00 - 2.00 2.00 - 4.00 Very Stiff Readily Indented by thumbnail
>50 Very Dense _ >30 >2.00 >4.00 Hard Difficult by thumbnail
Moisture Content Structure
Dry: Absence of moisture, dusty, dry to the touch Stratified: Alternating layers of material or color >6 mm thick
Damp: Some moisture but leaves no moisture on hand Laminated: Alternating layers < 6 mm thick
Moist: Leaves moisture on hand Fissured: Breaks along definate fracture planes
• Wet: Visible free water, likely from below water table Slickensided: Striated, polished, or glossy fracture planes
Plasticity Dry Strength Dilatancy Toughness Blocky: Cohesive soil that can be broken down into small
angular lumps which resist further breakdown
ML Non to Low Non to Low' Slow to Rapid Low, can't roll Lenses: Has small pockets of different soils, note thickness • •...
CL Low to Med. Medium to High None to Slow Medium Homogeneous: Same color and appearance threadhbLt, . , •
MH Med to High Low to Medium None to Slow Low to Medium 0111•41
CH Med to High High to V. High None High • •••• • 1 °. • •
Unified Soil Classification Chart (Visual - Manual Procedure) (Similar to ASTM Djsigltation [14488) °
_p.m
Major Divisions Group Typical Names • • •
Symbols °••••. - • •
Coarse Gravels: 50% Clean GW Well graded gravels and gravel-sand mixtures, littIetif n6 fines • • ••••
Grained or more Gravels GP Poorly- graded gravels and gravel -sand mixtures, No wino fines • • ° °. •
Soils: retained on Gravels GM Silty gravels, gravel -sand -silt mixtures • • . • • • • More than the No. 4 sieve with Fines GC Clayey gravels, gravel -sand -clay mixtures • • • •
50% retained Sands: more Clean SW Well- graded sands and gravelly sands, little or no fines • • . • • • •
• on No. 200 than 50% Sands SP Poorly- graded sands and gravelly sands, little or no firTes .... •100410
• sieve passing the Sands SM Silty sands, sand -silt mixtures • . • .... • .
No. 4 Sieve with Fines SC Clayey sands, sand -clay mixtures ...• _ _ _ •
Fine-Grained Gra and Cl Silt an Clays ML Inorganic sifts, rock flour, clayey silts • • • 040410
o Low Plan Fines CL Inorganic days of low to medium plasticity, gravelly days, sandy cI 7s, Tean clay? , ... •
50% or more OL Organic silt and organic silty clays of low plasticity
Passes No. MH Inorganic silts, clayey silts
200 Sieve Silt and Clays CH Inorganic days of high plasticity, fat clays
High Plasticity Fines OH Organic clays of medium to high plasticity
Highly Organic Soils PT Peat, muck, and other highly organic soils
C P - •.y Carlson Geotechnkal
P.O. Box 23814 CGT Job No. G0602953 Figure 4
remmoin
4014250 Tigard, Oregon 97281
Carlson Geotechnical FIGURE 5
G 0 7185 SW Sandburg Street, Suite 110
® I/� Tigard, OR 97223 BORING NUMBER B -1
1l50 Telephone: (503) 601 -8250
Fax: (503) 601 -8254 PAGE 1 OF 2
CLIENT Tualatin Valley Fire & Rescue PROJECT NAME Tigard Fire Station
PROJECT NUMBER G0602953 PROJECT LOCATION 12585 SW Walnut Street
DATE STARTED 11/27/06 ELEVATION DATUM Driveway at Walnut Street = 100 ft
DRILUNG CONTRACTOR Subsurface Technologies GROUND ELEVATION 96 ft
DRILLING METHOD HSA GROUND WATER LEVELS:
LOGGED BY M. David Irish CHECKED BY Ryan Houser .V. AT TIME OF DRILUNG 13.0 ft / Elev 83.0 ft
NOTES TAT END OF DRIWNG 12.0 ft / Elev 84.0 ft
ATTERBERG H
w U Z } N w w w o LIMITS w
a r}
0= EL co a i MATERIAL DESCRIPTION e w O Q W y z 1-6 O F_ F F- U>4 v'
d O 1 330> Y`-' >.. Z O co F.
C7 = W QZ u! oz 8 tr RO dJ 5r, C ur
0 y 1 0. 0 0 a a Z a
OL Soft, moist, brown, SILT TOPSOIL, contains rootlets 95 SPT 100 1 -1 -2
- - Soft to medium stiff, moist, brown, SILT X 66-1 (3)
ML -
- Becomes medium stiff at 3 feet bgs _ X SS -2 67 2 (5) 3
Medium stiff, very moist, brown, SANDY SILT
5 _ \/ _
90 x S S 100 2 �5 ; 35 63
- - - X SS-4 100 1-1-2 35 27 8
•.•• • •
10 • • •
Becomes soft at 10 feet bgs. SPT 1 -1 -1 •
- - 85 SS -5 100 (2) I . I • . • 74 • • •
1 Becomes wet at 12 feet bgs •••• • • ' • •
X SS$ 100 () 1 -Z 1 ••• 1 • • i III •••I ••
• • •
• ••••. • • • •
15 •• • •
•••••v --
�/ SPT 1 -1 -1 •• • ••.••
• 80 A 100 (2) 3 •
• • • • .83 83
- - SS -7 • •
••••■. • •
• • • i•• -•
- - ML - - •••• •
•• •
• • •
c ••.•
0
o
rn 20 `/
a _ - 8 X S-8 100 O(2)1 27 31 27 4 84
a
F
- - -
I 25 _
8 Becomes medium stiff and brown/grey at 25 feet bgs
_ - 70 SS-9 9 100 O(s� 39 53
w
x —
- - - -
0
o- - - -
..
o
>. - - - -
•
8 30 - - - -
(Continued Next Page)
R Carlson Geotechnical FIGURE G Sandburg Street. Suite 110
Tigard, OR 97223
Telephone: (503) 601 -8250 BORING NUMBER B -1
503-601 4250
Fax (503) 601 -8254
PAGE 2 OF 2
CLIENT Tualatin Valley Fire & Rescue PROJECT NAME Tigard Fire Station
• PROJECT NUMBER G0602953 PROJECT LOCATION 12585 SW Walnut Street
• ATTERBERG
Z
0 _ z w o LIMITS Z
U a >- �w W
o' O MATERIAL DESCRIPTION V. a o D< Y N j o ? F_ H F- U 6 o
w ¢ Z W °DU Z 8 ti 2O -7 N ° z w
30 cn tY
0. 0 0 a a a
- - Soft, wet, brown, SANDY SILT (continued) 65 49 sp'r 1 00 0 -1 -1 27 81
S -1C (2)
35 _
Becomes medium stiff and grey at 35 feet bgs SPT
60 X SPT
5S -11 100 2 (7) 35 82
- - ML - -
40 _ -
55 T 100 0 -2 -3 34 83
- -
X:: 10 (5)
•••• • .
- - • • •
••••
45 _ .
•••• - •
• 100 1 -2 -2 • • • 50 - - Xs5SP1 - (4) • .32 • S9 .. •
• • •
• • • • •
•• • • ••1.••
• • •
Medium stiff, wet, re /brown, LEAN CLAY • • • • • • • •
9 Y •.••• • • • •
_ _
•. • •
50 / CL •.••• •
• •
/ 2-2-4 •►•••. •.••
45 67 . • 35 31„ . 8 •
S 14 (6) .•••
X
•
.•
• •
• • .
Boring terminated at 51.5 feet bgs.
•• • . •
S Groundwater initially encountered at 13 feet bgs. • • • •
c Groundwater at 12 feet bgs at completion of drilling.
h
Boring backfilled with bentonite.
1-
z
2
C7
C'
C7
N
Z
0
0
V
S
2
V
W
0
O
W
C7
0
O
a
0
R Carlson Geotec FIGURE 6
("St Tigard OR 97223rg Street, Suite 110
OgilTi Ili • 11111203 Telephone: (503) 601 -8250 BORING NUMBER B -2
503-6011250 Fax: (503) 601 -8254 PAGE 1 OF 1
CLIENT Tualatin Valley Fire & Rescue PROJECT NAME Tigard Fire Station
PROJECT NUMBER G0602953 PROJECT LOCATION 12585 SW Walnut Street
DATE STARTED 11/27/06 ELEVATION DATUM Driveway at Walnut Street = 100 ft
DRIWNG CONTRACTOR Subsurface Technologies GROUND ELEVATION 95.5 ft
' DRILLING METHOD HSA GROUND WATER LEVELS:
LOGGED BY M. David Irish CHECKED BY Ryan Houser Q AT TIME OF DRILLING 11.0 ft / Elev 84.5 ft
NOTES AT END OF DRILLING —
ATTERBERG I-
a- e z w LIMITS w
x vi
z rr u) w a �- E-
w J MATERIAL DESCRIPTION > a E o O >; z a N w - 66 v o CO }`"o
O W iz W m0 ? O � O J� v) j V W
0 co te 0. 0 0 a a LL
OL Soft, moist, brown, SILT TOPSOIL, contains rootlets J 95 SPT 100 1 -1 -2
- - Medium stiff, moist, brown, SANDY SILT A ss-1 (3)
- -
- - - -)11n 100 2-2.4
(6)
5
90 X SPT 2 -3-3
SS -3 100 (6)
Becomes soft and very moist at 7.5 feet bgs SPT 0-1-2
- - - -XSS -4 100 (3)
ML - - • r.. • •
10 • • • 00.10
000040 40000
-` a SPT 1 00 0-1 -1 •
Becomes wet at 11 feet bgs - SS 5 ( • • • • • • • •
• • •
- - • • •
•000 •
SPT 0-1 -1 •.• .• • •
— XSS 6 100 (2) • • •
•• ••
- - • • • 000
• • • •
15 Becomes very soft at 14.5 feet bgs • • • •
80 X A SPT 1 -0-1 • • • •
- - SS -7 100 (1) •• •• •4 ••
• •
• • • 4 • • •
— - 00•• •
is — — • •4 ••• r
"— —
•r • r •
S _ _ •...
i- - -
O
vi • 20 - -
75
- - SS-T8 100 0-0-1 (1)
a
0. terminated at 21.5 feet bgs.
r. Groundwater initially encountered at 11 feet bgs.
Boring backfilled with bentonite.
to
z
f
J
0
V
z
CO
x
w U
F
O
W
LL
O
Y
..
O
V
•
R Carlson Geotechnical FIGURE 7
c p. _ _ 7185 SW Sandburg Street, Suite 110
® I Tigard, OR 97223 BORING NUMBER B -3
50.6014250
Telephone: (503) 601 -8250
Fax (503) 601 -8254
PAGE 1 OF 1
CLIENT Tualatin Valley Fire & Rescue PROJECT NAME Tigard Fire Station
. PROJECT NUMBER G0602953 PROJECT LOCATION 12585 SW Walnut Street
DATE STARTED 11/27/06 ELEVATION DATUM Driveway at Walnut Street = 100 ft
DRILLING CONTRACTOR Subsurface Technologies GROUND ELEVATION 94.5 ft
DRILUNG METHOD HSA GROUND WATER LEVELS:
LOGGED BY M. David Irish CHECKED BY Ryan Houser .Q AT TIME OF DRIWNG 10.0 ft / Elev 84.5 ft
NOTES AT END OF DRIWNG —
ATTERBERG f-
z a ° z w a, LIMITS
2 V co p r tr » cnw a s1- Pi
w = ap 0 MATERIAL DESCRIPTION >F LIED j oz 1"§- zs Nz o 2 V ti vo
o w a� O mo> -- D I-- 5 Ng H
w z w "z 8 9-„ I- gnw z °w
0 u) ce n. o U Q. a LL
- — = OL Soft, moist, brown, SILT TOPSOIL, contains rootlets l SPT 2 -2 -2
- - ' Medium stiff, moist, brown, SANDY SILT - .,.. -X SPT 33 (4)
- - - -X SPT 1 - -
S S - 44 (4)
- - 90
5
SPT 2 -3.3
- - _ SS-3 100 (6)
- - Becomes soft and very moist at 7.5 feet bgs - - SPT 100 1 -2 -1
(3)
85 ••••• • • •
• •
•••• • •••1•
10 Q .
Becomes wet at 10 feet bgs • • • •' • •
SPT 100 1 -1 -1 . • S••• 11 • •
'- .. ML SS-5 (2) • ••••
- - • 1 •
•••• •
. • • • •
Becomes very soft at 12.5 feet bgs _ _V SPT 0 -0-0 • • ii ••••••
SS -6 100 (0) • • • • I • • . • •
• • • •••
80 ••••Il • • • •
15 ••••I • •• • •
)1 • SS7 100 • 0-1-1 .• •. •
• •.••
• • •11•• •
•••. •
• .
• • •
1,- _ •, • • •
• •
G - - ••••
o 75
o
vi 20
a- - - -X SSPT S-8 100 1(1)
a
0. Boring terminated at 21.5 feet bgs.
Groundwater initially encountered at 10 feet bgs.
0
Boring backfilled with bentonite.
U)
z
m
0
Q
0
�
0
W
r-
U)
W
0
W
0
Y
a .
0
0
U
A
Carlson Geotechnical
c ,PRl y 7185 SW Sandburg Street, Suite 110 Figure 8
®
Tigard, OR 97223
503-6014250 Telephone: (503) 601-8250 CPT NUMBER CPT -1
Fax: (503) 601 -8254 PAGE 1 OF 3
CLIENT Tualatin Valley Fire & Rescue PROJECT NAME Tigard Fire Station
PROJECT NUMBER G0602953 PROJECT LOCATION 12585 SW Walnut Street
DATE STARTED 11/29/06 COMPLETED 11/29/06 GROUND ELEVATION 95 ft
DRILLING CONTRACTOR Subsurface Technologies NOTES Driveway at Walnut Street assumed at 100 ft
DEPTH FRICTION CONE RESISTANCE FRICTION INTERPRETED ELEV.
(feet) (tsf) (tsf) RATIO ( %) SOIL DESCRIPTION (feet)
0 4 3 2 1 0 0 20 40 60 80 100 120 140160 0 2 4 6 8 95
Po oy SILTY CLAY TO CLAY
III/I
_ iiii•
CLAY __
•
I
•
•
•
• \ -
$% CLAYEY SILT TO SILTY CLAY
. • � ' •III
5— ................._ ... ...... .........._.... .... _.................... • • — 90
; " ' • • • ' SANDY SILT TO CLAYEY SILT
iiiii CLAYEY SILT TO SILTY CLAY -
IoIII
iiiii
OM
IIII
iiiii
VIII
VI II
iiiii • • •
t IiIII .••• • •
10 - ... ............... .. ;.....: ; ... W % • •••..• -89••. •
•
• iiiii
•••• I •
-. •
I/II/ • • • - •
•
• I0III ••••
• • •••1 ••
III /I
• •
- • VIII •••• •
VIII • • • • •
I /III • _
• II I • • • - •••11••
SANDY SILT TO CLAYEY SILT • •
• • • •.•
•
I CLAYEY SILT TO SILTY CLAY • • • • • •
•
•
. SANDY SILL YEY SILT • - ••∎ ••
• •• •• SA •
SILTY SANg TO ;ANDY SILT • • • • • • ∎ • •
15— .......... ....._... . • • • • •••. • — •
• - •••• •
• SANDY SILT TO CLAYEY SILI••••. •••■1 ••
- •• • - • •
•
•
SILTY SAND TO SANDY SILT
•
SANDY SILT TO CLAYEY SILT
•
•
• OW CLAYEY SILT TO SILTY CLAY
VIII
VIII
20— ........... ......... 0 75
VIII • O - VIII
0 VIII
H 1111 SANDY SILT TO CLAYEY SILT
F OM CLAYEY SILT TO SILTY CLAY
z - • -
• VIII
o
• iiiii
t7 _ IIIii
iiiii
.?, • • . VIII
FAT CLAY / ELASTIC SILT I
a
0 25— _ 70
(Continued Next Page)
Carlson Geotechnical Figure 8
G P_ e .� o 7185 SW Sandburg Street, Suite 110 9
�
7_ 4,-
Tigard, OR 97223 CPT NUMBER CPT -1
Telephone: (503) 601 -8250
Fax (503) 601 -8254 PAGE 2 OF 3
CLIENT Tualatin Valley Fire & Rescue PROJECT NAME Tigard Fire Station
• PROJECT NUMBER G0602953 PROJECT LOCATION 12585 SW Walnut Street
DATE STARTED 11/29/06 COMPLETED 11/29/06 GROUND ELEVATION 95 ft
DRILLING CONTRACTOR Subsurface Technologies NOTES Driveway at Walnut Street assumed at 100 ft
DEPTH FRICTION CONE RESISTANCE FRICTION INTERPRETED ELEV.
(feet) (tsf) (tsf) RATIO ( %) SOIL DESCRIPTION (feet)
25 4 3 2 1 0 0 20 40 60 80 100 120 140160 0 2 4 6 8 70
so SANDY SILT TO CLAYEY SILT
(continued)
- \ SILTY SAND TO SANDY SILT
( : •
SANDY SILT TO CLAYEY SILT
SILTY SAND TO SANDY SILT -
•
SANDY SILT TO CLAYEY SILT
iii CLAYEY SILT TO SILTY CLAY _
iii
30 — SANDY SILT TO CLAYEY SILT —
FAT CLAY I ELASTIC SILT
- An' CLAYEY SILT TO SILTY CLAY
A SILTY CLAY TO CLAY f
ad r
�• CLAYEY SILT TO SILTY CLAY
- ,iii' SILTY CLAY TO CLAY
/,'O.' CLAYEY SILT TO SILTY CLAY
ii SILTY CLAY TO CLAY J
•
• ii CLAYEY SILT TO SILTY CLAY -
000
SANDY SILT IQ CWYEY S j • . •
• ••••Il •
•••• • •
- • • • -
II
••••
• • .•
•
- _ • • •
„�; CLAYEY SIL SILTY CLAY • _ ■
SANDY SILT TO CLAYEY SIT • • • • •
-
��� CLAYEY SIL770SILTY CLAY r • • • • •
SANDY SNJ39CEAYEY SS : -: , - •
CLAYEY §ILTYCLAY• • / •
SANDY SILT(TO CLAYEY SILT •
•• •• •
••••
40 — ........... •• •• ••... ..... ...._....- ••• ..... ................ ..........._.... • • — 55
• • •••• •
•••• •
•• •
• • • _ •
•• • • •
••••
Il. FAT CLAY I ELASTIC SILT
' SANDY SILT TO CLAYEY SILT
R 45— .. - _. • •• •• -• ....... • -• —50
•
c _ _ •
I •
H •
2 - •
U' •
_ • SILTY SAND TO SANDY SILT -
- SANDY SILT TO CLAYEY SILT -
aa CLAYEY SILT TO SILTY CLAY
50 45
(Continued Next Page)
R Carlson Geotechnical Figure 8
G y Q� 0 7185 SW Sandburg Street, Suite 110
Tigard, OR 97223 CPT NUMBER CPT -1
503 Telephone: (503) 601-8250
Fax: (503) 601 -8254 PAGE 3 OF 3
CUENT Tualatin Valley Fire & Rescue PROJECT NAME Tigard Fire Station
PROJECT NUMBER G0602953 PROJECT LOCATION 12585 SW Walnut Street
DATE STARTED 11/29/06 COMPLETED 11/29/06 GROUND ELEVATION 95 ft
DRILUNG CONTRACTOR Subsurface Technologies NOTES Driveway at Walnut Street assumed at 100 ft
DEPTH FRICTION CONE RESISTANCE FRICTION INTERPRETED ELEV.
(feet) (tsf) (tsf) RATIO ( %) SOIL DESCRIPTION (feet)
50 4 3 2 1 0 0 20 40 60 80 100 120 140160 0 2 4 6 8
} 0% SILTY CLAY TO CLAY (continued) 45
. (\ iii
- \ CLAY -
•
tel SILTY CLAY TO CLAY
' r CLAYEY SILT TO SILTY CLAY -
SANDY SILT TO CLAYEY SILT
55— ..... —40
•
•
60—
SILTY SAIATA SILT ••••• ••• iiiii
'- � •••• _ • •
Ill lll • • • •
••••
• •
SANDY SILjj%SLAYEY SILT • - • •
•
•• •
• • •
- •• •
• • • •••
• • •
• •• • •
SILTY SANG M L(NDY SIL • ••• •
•• •• •
65 — SANDY SIIII4F AYEYSBA••• — •• •
• • •••• 0
•••• •
• CLAYEY SILT TO SILTY CLik • f = • • _ • • • • 4 •
•• • • •
•
•
SANDY SILT TO CLAYEY SILT • • • .
•
•
•
•
�� CLAYEY SILT TO SILTY CLAY
ii
r i 70 — ::: - 25
%% LEAN CLAY / SILT
ili
8 - iii -
o
ui
D Practical Refusal at 71.19 feet bgs.
rz Soil type based on 1983 UBC
o Bottom of hole at 71.2 feet.
a
cI
c
or
• •
I- •
0 •
LIQUEFACTION ANALYSIS
TIGARD FIRE STATION
Hole No. =CPT -1 Water Depth =12 ft Surface Elev. =95 FT Magnitude =7
Acceleration =0.33g
Shear Stress Ratio Factor of Safety Settlement Soil Description
(ft) 0 1 0 1 5 0 (in.) 10
I 1 I I I I I I I i I I I I I I I I I I I I I I I I % Clay (CL) to SILTY CLAY (CL)
–
– r . – /
Sandy silt (ML) to clayey silt (ML)
°— Clayey silt (ML) to silty clay (CL)
z
– V_.—_ .
r Sandy silt (ML) to clayey silt (ML) to silty
— 15 L r sand (SM)
r
11111 Clayey silt (ML) to silty clay (CL)
—_ I WAN tie s�
–
— t San�d k t8 [y s M1) to clayey
l.- silt (ML)
— 30
•
Clayey sift (ML) to silty clay (CL)
–
– 11111 Sandy silt (ML) to clayey silt (ML)
– Clayey silt (ML) to silty clay (CL)
Sandy silt (ML) to clayey silt (ML)
— 45
– Sandy sift (ML) to silty sand (SM) to clayey
WO (CL) to lean clay (CL) • • • • .
•••• • •
Sandy AWN clayey sliT(ML)
I ••.• • •
- 60 '•••
;VI ts SM) 1A sanit ciM I
– dy car •
si i ltAg o clayey silt KL; • •
• • • • •
•• •
– • • •
•••i
– fs =1 Clayey Silt (tiA11 to silty of (ELito Lean • •
• CRR — CSR — Wet— Dry— clay (CO tt lilt11IL)
— 75 Shaded Zone has Liquefaction Potential S = 2.67 in. • • • • •
••••• •
•••• •••11 •
• •
S - • • ••••
•••• •
•• •
�- • • •
•• • • •
- 90
•
:
a -105
a
1
CivilTech Corporation G0602953 Plate A -1
i
CPT data - CPT -1, 12- 14- 06.sum
******************************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * **
* * * * * * * * * * * * * * * **
LIQUEFACTION ANALYSIS CALCULATION SHEET
Copyright by CivilTech Software
www.civiltech.com
(425) 453 -6488 Fax (425) 453 -5848
******************************************************* * * ** * * * * * * * * * * * * * * * * * * * * * * ** * **
* * * * * * * * * * * * * * * **
Licensed to , 1/3/2007 8:33:37 AM
Input File Name: G: \GEOTECH \PROJECTS \2006 Projects \Tigard Fire
Station \LiquefyPro Analyses \CPT data - CPT -1, 12- 14- 06.liq
Title: TIGARD FIRE STATION
Subtitle: G0602953
surface Elev. =95 FT
Hole No. =CPT -1
Depth of Hole= 71.2 ft
water Table during Earthquake= 12.0 ft
Water Table during In -Situ Testing= 12.0 ft
Max. Acceleration= 0.33 g
Earthquake Magnitude= 7.0
Input Data:
surface Elev. =95 FT
Hole No. =CPT -1
Depth of Hole =71.2 ft
water Table during Earthquake= 12.0 ft
water Table during In -Situ Testing= 12.0 ft
Max. Acceleration =0.33 g
Earthquake Magnitude =7.0
1. CPT calulation Method: Modify Robertson*
2. Settlement Analysis Method: Ishihara / Yoshimine*
3. Fines correction for Liquefaction: Stark /Olson et al.* .... • •
4. Fine correction for settlement: During Liquefaction* • 5 ••••••
5. Settlement Calculation in: All zones* •
•... • •
6. Hammer Energy Ratio, Ce =1 • • •
7. Borehole Diameter, cb =1 •••• •
8. Sampeling Method, Cs =1 • •
�•�•
fs =1, Plot one CSR (fs =1) . • •
8. use Curve smoothing: Yes* •• • •
* Recommended Options .• .. ,
• • • •..
In -Situ Test Data: '..' • '.
Depth qc fc Gamma Fines D50 • . •
ft tsf tsf pcf % mm •• •• •
....
0.0 0.0 0.0 100.0 NoLiq 0.5 • ••••• • ••••• • •
0.3 16.7 0.6 100.0 NoLiq 0.5 .. •
0.7 13.7 0.4 100.0 NoLiq 0.5 ••• •• •
1.0 9.6 0.3 100.0 NoLiq 0.5 •.•.
1.3 7.0 0.3 100.0 NoLiq 0.5
1.6 5.2 0.2 100.0 NoLiq 0.5
2.0 4.9 0.3 100.0 NoLiq 0.5
2.3 5.9 0.4 100.0 NoLiq 0.5
2.6 5.6 0.5 100.0 NoLiq 0.5
3.0 11.0 0.5 100.0 NoLiq 0.5
3.3 8.9 0.6 100.0 NoLiq 0.5
3.6 10.5 0.5 100.0 NoLiq 0.5
3.9 17.5 0.9 105.0 NoLiq 0.5
4.3 21.8 0.9 105.0 NoLiq 0.5
4.6 19.2 0.8 105.0 NoLiq 0.5
4.9 24.0 0.6 105.0 NoLiq 0.5
5.3 25.2 0.5 105.0 63.0 0.5
5.6 23.2 0.4 105.0 63.0 0.5
5.9 21.3 0.4 105.0 63.0 0.5
6.2 19.2 0.4 105.0 63.0 0.5
6.6 20.0 0.4 , 105.0 63.0 0.5
6.9 17.6 0.2 105.0 63.0 0.5
Page 1
CPT data - CPT -1, 12- 14- 06.sum
7.2 15.0 0.2 105.0 63.0 0.5
7.6 14.8 0.5 105.0 63.0 0.5
7.9 12.8 0.2 105.0 63.0 0.5
8.2 11.6 0.1 105.0 63.0 0.5
8.5 11.9 0.2 105.0 63.0 0.5
8.9 11.6 0.1 105.0 63.0 0.5
9.2 10.3 0.1 105.0 63.0 0.5
9.5 11.5 0.2 105.0 63.0 0.5
9.8 14.0 0.3 105.0 63.0 0.5
10.2 15.0 0.2 105.0 74.0 0.5
10.5 13.2 0.3 105.0 74.0 0.5
10.8 11.3 0.2 105.0 74.0 0.5
11.1 12.1 0.2 105.0 74.0 0.5
11.5 11.6 0.2 105.0 74.0 0.5
11.8 11.9 0.3 105.0 74.0 0.5
12.1 15.6 0.3 105.0 74.0 0.5
12.5 12.5 0.3 105.0 74.0 0.5
12.8 18.6 0.4 105.0 74.0 0.5
13.1 24.5 0.3 105.0 74.0 0.5
13.4 15.1 0.1 105.0 74.0 0.5
13.8 9.4 0.1 105.0 74.0 0.5
14.1 13.7 0.3 105.0 74.0 0.5
14.4 27.0 0.3 105.0 74.0 0.5
14.8 33.1 0.3 105.0 74.0 0.5
15.1 37.5 0.3 105.0 83.0 0.5
15.4 37.8 0.3 105.0 83.0 0.5
15.8 33.6 0.7 105.0 83.0 0.5
16.1 35.3 0.8 105.0 83.0 0.5
16.4 40.0 0.8 105.0 83.0 0.5
16.7 44.9 0.5 105.0 83.0 0.5
17.1 35.9 0.4 105.0 83.0 0.5
17.4 14.3 0.3 105.0 83.0 0.5
17.7 16.6 0.4 105.0 83.0 0.5
18.0 23.1 0.3 105.0 83.0 0.5
18.4 14.6 0.3 105.0 83.0 0.5
18.7 10.8 0.0 105.0 83.0 0.5
19.0 12.9 0.2 105.0 83.0 0.5
19.4 13.3 0.7 105.0 83.0 0.5
19.7 17.3 0.4 105.0 83.0 0.5 •••• • •
20.0 16.0 0.3 105.0 84.0 0.5 • • •
20.3 10.3 0.3 105.0 84.0 0.5 • (boo*
20.7 16.8 0.4 105.0 84.0 0.5 •.•
21.0 13.2 0.1 105.0 84.0 0.5 ••••
21.3 7.3 0.0 105.0 84.0 0.5 .
21.6 11.4 0.0 105.0 84.0 0.5 • •••• • • • •
22.0 16.1 0.8 105.0 84.0 0.5 •• •
22.3 34.8 0.5 105.0 84.0 0.5 •
22.6 11.7 0.4 105.0 84.0 0.5 • • • ••• •
23.0 13.8 0.6 105.0 84.0 0.5 '•.'
•
23.3 31.1 0.9 105.0 84.0 0.5 • • •
23.6 13.9 0.3 105.0 84.0 0.5 •• •• •
24.0 6.1 0.1 105.0 84.0 0.5 ••••
24.3 8.9 0.1 105.0 84.0 0.5 • •••• • •••• •
•
24.6 6.9 0.0 105.0 84.0 0.5
24.9 6.6 0.0 105.0 53.0 0.5 • • • •
25.3 5.9 0.1 105.0 53.0 0.5 •�
25.6 23.4 0.1 105.0 53.0 0.5
25.9 23.5 0.1 105.0 53.0 0.5
26.3 20.4 0.2 105.0 53.0 0.5
26.6 15.0 0.2 105.0 53.0 0.5
26.9 9.4 0.2 105.0 53.0 0.5
27.2 22.0 0.3 105.0 53.0 0.5
27.6 46.4 0.3 105.0 53.0 0.5
27.9 45.4 0.4 105.0 53.0 0.5
28.2 39.7 0.3 105.0 53.0 0.5
28.5 31.6 0.7 105.0 53.0 0.5
28.9 13.2 0.3 105.0 53.0 0.5
29.2 16.0 0.4 105.0 53.0 0.5
29.5 20.3 0.3 105.0 53.0 0.5
29.9 8.9 0.1 105.0 53.0 0.5
30.2 8.1 0.0 105.0 81.0 0.5
30.5 17.5 0.2 105.0 81.0 0.5
30.8 11.8 0.1 105.0 81.0 0.5
31.2 10.0 0.1 105.0 81.0 0.5
Page 2
J
CPT data - CPT -1, 12- 14- 06.sum
31.5 7.8 0.0 105.0 81.0 0.5
31.8 7.2 0.0 105.0 81.0 0.5
32.2 13.8 0.3 105.0 81.0 0.5
32.5 8.2 0.3 105.0 81.0 0.5
32.8 9.0 0.0 105.0 81.0 0.5
33.1 11.0 0.3 105.0 81.0 0.5
33.5 26.4 1.1 105.0 81.0 0.5
33.8 27.5 1.1 105.0 81.0 0.5
34.1 15.8 0.3 105.0 81.0 0.5
34.5 14.5 0.3 105.0 81.0 0.5
34.8 30.7 1.2 105.0 81.0 0.5
35.1 31.4 1.1 105.0 82.0 0.5
35.4 30.7 0.7 105.0 82.0 0.5
35.8 23.9 0.5 105.0 82.0• 0.5
36.1 20.7 0.2 105.0 82.0 0.5
36.4 16.4 0.3 105.0 82.0 0.5
36.8 38.8 0.5 105.0 82.0 0.5
37.1 24.0 0.6 105.0 82.0 0.5
37.4 21.0 0.5 105.0 82.0 0.5
37.7 13.2 0.1 105.0 82.0 0.5
38.1 10.5 0.1 105.0 82.0 0.5
• 38.4 18.2 0.5 105.0 82.0 0.5
38.7 20.0 0.2 105.0 82.0 0.5
39.0 12.0 0.2 105.0 82.0 0.5
39.4 23.3 0.4 105.0 82.0 0.5
39.7 39.7 0.6 105.0 82.0 0.5
40.0 20.2 0.3 105.0 83.0 0.5
40.3 11.7 0.1 105.0 83.0 0.5
40.7 18.4 0.3 105.0 83.0 0.5
41.0 18.4 0.2 105.0 83.0 0.5
41.3 16.0 0.2 105.0 83.0 0.5
41.7 14.6 0.2 105.0 83.0 0.5
42.0 38.9 0.5 105.0 83.0 0.5
42.3 22.4 0.5 105.0 83.0 0.5
42.7 19.0 0.3 105.0 83.0 0.5
43.0 11.5 0.1 105.0 83.0 0.5
43.3 14.4 0.1 105.0 83.0 0.5
43.6 11.0 0.0 105.0 83.0 0.5
44.0 9.5 0.0 105.0 83.0 0.5 •••• • •
44.3 8.8 0.0 105.0 83.0 0.5 • • •
44.6 11.3 0.0 105.0 83.0 0.5 •
45.0 10.7 0.0 105.0 83.0 0.5 • •.•
45.3 12.1 0.0 105.0 83.0 0.5 ••••
•
45.6 11.4 0.1 105.0 89.0 0.5 • •
45.9 11.4 0.1 105.0 89.0 0.5 • •••• • • • •
46.3 10.7 0.0 105.0 89.0 0.5 •• •
46.6 10.0 0.0 105.0 89.0 0.5 • • •
46.9 10.9 0.0 105.0 89.0 0.5 • • • •••• ••• •�
47.2 13.7 0.1 105.0 89.0 0.5 • • • •
•• • •
47.6 19.6 0.2 105.0 89.0 0.5 • • •
47.9 31.8 0.3 100.0 NoLiq 0.5 •• •• •
48.2 39.3 0.5 100.0 NoLiq 0.5 ••••
•
48.6 40.3 1.0 100.0 NoLiq 0.5 • ••••• •••• • •
48.9 50.1 1.7 100.0 NoLiq 0.5 •• •
49.2 59.5 1.3 100.0 NoLiq 0.5 • • • •
•• • • •
49.5 44.3 1.1 100.0 NoLiq 0.5 ••••
49.9 34.7 1.5 100.0 NoLiq 0.5
50.2 37.2 1.7 100.0 NoLiq 0.5
50.5 46.0 2.0 100.0 NoLiq 0.5
50.8 63.4 3.2 100.0 NoLiq 0.5
51.2 58.3 3.0 100.0 NoLiq 0.5
51.5 53.2 2.7 100.0 NoLiq 0.5
51.8 50.5 2.6 100.0 NoLiq 0.5
52.2 47.6 2.7 100.0 NoLiq 0.5
52.5 48.3 2.9 100.0 NoLiq 0.5
52.8 46.7 2.7 100.0 NoLiq 0.5
53.2 46.6 2.5 100.0 NoLiq 0.5
53.5 50.2 2.7 100.0 NoLiq 0.5
53.8 45.9 2.1 100.0 NoLiq 0.5
54.1 47.1 2.1 100.0 NoLiq 0.5
54.5 49.9 1.4 100.0 NoLiq 0.5
54.8 35.3 0.7 100.0 NoLiq 0.5
55.1 31.7 0.6 100.0 NoLiq 0.5
55.5 35.5 0.7 100.0 NoLiq 0.5
Page 3
• ■ i, •
CPT data - CPT -1, 12- 14- 06.sum
55.8 40.5 0.8 100.0 NoLiq 0.5
56.1 39.1 0.6 100.0 NoLiq 0.5
56.4 35.9 0.7 100.0 NoLiq 0.5
56.8 32.9 0.6 100.0 NoLiq 0.5
. '57.1 29.5 0.6 100.0 NoLiq 0.5
57.4 28.1 0.4 100.0 NoLiq 0.5 •
57.7 27.7 0.4 100.0 NoLiq 0.5
58.1 28.6 0.4 100.0 NoLiq 0.5
58.4 28.3 0.4 100.0 NoLiq 0.5
58.7 30.1 0.4 100.0 NoLiq 0.5
59.1 33.5 0.6 100.0 NoLiq 0.5
59.4 31.5 0.6 100.0 NoLiq 0.5
59.7 31.5 0.5 100.0 NoLiq 0.5
60.0 32.8 0.5 100.0 NoLiq 0.5
60.4 36.9 0.5 100.0 NoLiq 0.5
60.7 31.9 0.4 100.0 NoLiq 0.5
61.0 30.9 0.3 100.0 NoLiq 0.5
61.3 36.7 0.4 100.0 NoLiq 0.5
61.7 34.9 0.5 100.0 NoLiq 0.5
62.0 31.9 0.4 100.0 NoLiq 0.5
62.3 35.0 0.5 100.0 NoLiq 0.5
62.7 41.3 0.8 100.0 NoLiq 0.5
63.0 34.4 0.7 100.0 NoLiq 0.5
63.3 38.3 0.6 100.0 NoLiq 0.5
63.7 43.1 0.9 100.0 NoLiq 0.5
64.0 63.2 1.4 100.0 NoLiq 0.5
64.3 56.3 1.1 100.0 NoLiq 0.5
64.6 48.3 0.8 100.0 NoLiq 0.5
• 65.0 47.6 0.9 100.0 NoLiq 0.5
65.3 44.2 1.0 100.0 NoLiq 0.5
65.6 48.5 1.1 100.0 NoLiq 0.5
65.9 76.2 3.3 100.0 NoLiq 0.5
66.3 76.0 2.7 100.0 NoLiq 0.5
66.6 57.5 1.8 100.0 NoLiq 0.5
66.9 54.1 1.3 100.0 NoLiq 0.5
67.3 45.5 0.8 100.0 NoLiq 0.5
67.6 49.8 1.1 100.0 NoLiq 0.5
67.9 49.3 1.4 100.0 NoLiq 0.5
68.2 53.9 1.7 100.0 NoLiq 0.5 ••.. • •
68.6 56.1 1.9 100.0 NoLiq 0.5 •
68.9 56.4 1.8 100.0 NoLiq 0.5 • ••••
69.2 66.4 1.9 100.0 NoLiq 0.5 • • • '' •.•
69.6 73.3 2.7 100.0 NoLiq 0.5 • • ••••
69.9 80.3 3.3 100.0 NoLiq 0.5 • • •
70.2 63.0 2.4 100.0 NoLiq 0.5 •';••• • • 70.5 65.8 3.7 100.0 NoLiq 0.5 •• •
70.9 60.8 3.2 100.0 NoLiq 0.5 • ••••••
71.2 59.9 3.2 100.0 NoLiq 0.5 • • • •••
• • • •
.. • •
Output Results: •••••• • •
Settlement of saturated sands =2.65 in. • •••• •
settlement of dry sands =0.02 in. • • •••• •
Total settlement of saturated and dry sands =2.67 in. •••� •• • •
Differential Settlement =1.333 to 1.760 in. • • •
•...
Depth CRRm CSRfs F.S. S_sat. S_dry S_all
ft w /fs in. in. in.
0.00 2.00 0.21 5.00 2.65 0.02 2.67
2.00 2.00 0.21 5.00 2.65 0.02 2.67
4.00 2.00 0.21 5.00 2.65 0.02 2.67
6.00 0.18 0.21 5.00 2.65 0.02 2.66
8.00 0.19 0.21 5.00 2.65 0.01 2.66
10.00 0.24 0.21 5.00 2.65 0.00 2.65
12.00 2.00 0.21 5.00 2.65 0.00 2.65
14.00 2.00 0.23 5.00 2.43 0.00 2.43
16.00 0.24 0.24 0.98* 1.93 0.00 1.93
18.00 0.14 0.26 0.53* 1.61 0.00 1.61
20.00 2.00 0.27 5.00 1.49 0.00 1.49
22.00 2.00 0.28 5.00 1.28 0.00 1.28
24.00 2.00 0.29 5.00 1.22 0.00 1.22
26.00 0.11 0.30 0.36* 1.00 0.00 1.00
28.00 0.13 0.30 0.42* 0.59 0.00 0.59
Page 4
•
CPT data - CPT -1, 12- 14- 06.sum
30.00 2.00 0.31 5.00 0.42 0.00 0.42
32.00 2.00 0.31 5.00 0.42 0.00 0.42
34.00 2.00 0.31 5.00 0.42 0.00 0.42
36.00 2.00 0.31 5.00 0.42 0.00 0.42
38.00 2.00 0.31 5.00 0.31 0.00 0.31
40.00 2.00 0.31 5.00 0.20 0.00 0.20
42.00 0.13 0.31 0.43* 0.16 0.00. 0.16
44.00 2.00 0.31 5.00 0.10 0.00 0.10
46.00 2.00 0.31 5.00 0.10 0.00 0.10
48.00 2.00 0.30 5.00 0.00 0.00 0.00
50.00 2.00 0.30 5.00 0.00 0.00 0.00
52.00 2.00 0.30 5.00 0.00 0.00 0.00
54.00 2.00 0.30 5.00 0.00 0.00 0.00
56.00 2.00 0.29 5.00 0.00 0.00 0.00
58.00 2.00 0.29 5.00 0.00 0.00 0.00
60.00 2.00 0.28 5.00 0.00 0.00 0.00
62.00 2.00 0.28 5.00 0.00 0.00 0.00
64.00 2.00 0.27 5.00 0.00 0.00 0.00
66.00 2.00 0.27 5.00 0.00 0.00 0.00
68.00 2.00 0.27 5.00 0.00 0.00 0.00
70.00 2.00 0.26 5.00 0.00 0.00 0.00
* F.S.<1, Liquefaction Potential Zone
(F.S. is limited to 5, CRR is limited to 2, CSR is limited to 2)
units Depth = ft, Stress or Pressure = tsf (atm), Unit weight = pcf,
settlement = in.
CRRm Cyclic resistance ratio from soils
CSRfs cyclic stress ratio induced by a given earthquake (with user
request factor of safety)
F.s. Factor of safety against liquefaction, F.S. =cRRm /CSRfs
s_sat settlement from saturated sands
s_dry Settlement from dry sands
s_all Total settlement from saturated and dry sands
NoLiq No- Liquefy Soils
.... • •
• • •
•
••••
•••• • •
• • • •
••••
• •
• • •
•••• •
• • • • •
•• •
• • •
•• ••
• • • •••
• • • •
•• • •
• • •
•• •• •
••••
• • •••• •
•••• •
•• •
• • •
• • • •
••••
Page 5