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GEOTECHNICAL REPORT
VIA 405 APARTMENTS
Submitted To: Mr. Craig Koeppler, Vice President RVA Cinema LLC Parkway Capital, Inc.
520 Pike Street, Suite 1500 Seattle, WA 98101
Submitted By: Golder Associates Inc. 18300 NE Union Hill Road, Suite 200
Redmond, WA 98052
March 20, 2017 Project No.: 1771669.100 REPORT
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EXECUTIVE SUMMARY
Golder Associates Inc. (Golder) is pleased to present the results of our geotechnical investigation to RVA
Cinema LLC Parkway Capital for the design of the Via 405 Apartment building proposed at 25 South Grady
Way in Renton, Washington (Site). The building will contain a two level concrete parking podium with six
levels of wood-frame residential units above. The residential units will wrap around a central courtyard. No
below grade structures are planned. The new development will be built on the footprint of an existing
cinema building which was constructed around 1988. The following executive summary is intended to
provide an overview of the geotechnical report and findings. Please refer to the main body of the report for
detailed recommendations.
Golder reviewed the previous geotechnical report prepared by GeoEngineers following the July 1987 geotechnical investigation for the existing cinema building. Geotechnical
explorations consisted of four boreholes located at the north, east, and south sides of the Site. The boreholes were advanced through alluvium to bedrock. The cinema building
was constructed on a timber pile supported foundation. For this report Golder contracted InSitu Engineering to conduct four Cone Penetration Tests (CPTs) to complement the
previous boreholes. The CPT explorations were advanced to bedrock and completed in February 2017.
The general soil profile consists of about 2.5 to 7 feet of fill (medium dense to dense sand and silty sand) overlaying alluvial deposits. The alluvium consists of a non-liquefiable soft
to very stiff silt and organic silt layer with the variable thickness of 0.5 to 12 feet overlaying a medium dense liquefiable sand layer. The alluvial deposit is underlain with varying
thickness of highly weathered sandstone in the form of medium dense to very dense fine or fine to medium sand. Moderately hard sandstone was encountered at depths of 13 to
about 48 feet, generally sloping down from southeast to northwest of the site. Groundwater levels were measured at 11, 8.5, 8.5, and 5.5 feet below the ground surface in Borings
B-1, -2, -3, and -4, respectively, in July 1987. Golder relied on the groundwater information from the 1987 boreholes, since the CPT data was inconclusive to determine groundwater
level.
According to our liquefaction assessment, the loose and medium dense alluvium and the
medium dense highly weathered sandstone below the water table identified in our CPT explorations are susceptible to seismic liquefaction with about 2.5 to 3 inches of total
liquefaction-induced settlement. Golder proposes ground improvement below the new foundation to provide liquefaction mitigation as well as bearing capacity improvement. The
new building foundation would consist of spread footings bearing on the improved ground conditions.
We propose that the existing timber piles beneath the cinema building be allowed to remain in place below the new apartment building foundation; however, pile caps located at 1.5 to
4 feet below finished grade will be removed as needed. The existing piles would not be relied upon as structural foundation bearing members for the new foundation. Ground
improvement elements consisting of rammed aggregate piers, grouted stone columns, or rigid intrusions would be added to provide an improved zone of soil capable of supporting
the new foundation loads.
Geologic critical areas such as severe erosion, steep slopes, landslides, aquifer recharge
areas, abandoned coal mines, and liquefaction-induced lateral spreading were examined at the project site. The Site is not located in an abandoned coal mine hazard or aquifer
recharge area and the level of risk from erosion, steep slopes, landslides and lateral spreading are judged to be low.
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Table of Contents
EXECUTIVE SUMMARY ........................................................................................................................ ES-1
1.0 PROJECT INFORMATION AND SITE DESCRIPTION ................................................................... 1
2.0 FIELD EXPLORATIONS, LABORATORY AND IN-SITU TESTING ................................................ 2
3.0 SUBSURFACE CONDITIONS ......................................................................................................... 3
3.1 Soil Conditions ............................................................................................................................. 3
3.2 Groundwater Conditions .............................................................................................................. 3
3.3 Bedrock Depth.............................................................................................................................. 4
4.0 CRITICAL AREAS ASSESSMENT .................................................................................................. 5
4.1 Severe Erosion ............................................................................................................................. 5
4.2 Steep Slopes ................................................................................................................................ 5
4.3 Landslides .................................................................................................................................... 5
4.4 Wellhead Protection Areas ........................................................................................................... 5
4.5 Abandoned Coal Mine .................................................................................................................. 6
4.6 Seismic Hazards .......................................................................................................................... 6
4.6.1 Surface Rupture ....................................................................................................................... 6
4.6.2 Liquefaction and Induced Settlement ...................................................................................... 6
4.6.3 Liquefaction-Induced Lateral Spreading .................................................................................. 7
4.6.4 Seismically Induced Landslides ............................................................................................... 7
5.0 ENGINEERING RECOMMENDATIONS ......................................................................................... 8
5.1 Foundation Options and Recommendations ................................................................................ 8
5.1.1 Pile Supported Foundation: Auger-Cast Piles ......................................................................... 8
5.1.2 Shallow Foundations with ground improvement ...................................................................... 9
5.2 Ground Improvement Options .................................................................................................... 11
5.3 Seismic Design........................................................................................................................... 12
5.3.1 Site Class ............................................................................................................................... 12
5.3.2 Ground Motion Parameters .................................................................................................... 13
5.4 Slab Subgrade............................................................................................................................ 14
5.4.1 Structural Fill Placement and Compaction ............................................................................. 14
6.0 CONSTRUCTION CONSIDERATIONS ......................................................................................... 16
6.1 Removal of Existing Pile Caps ................................................................................................... 16
6.2 Earthworks ................................................................................................................................. 16
6.2.1 Subgrade and Foundation Preparation .................................................................................. 16
6.2.2 Use of Onsite Excavated Soil ................................................................................................ 16
6.2.3 Use of Reclaimed Concrete Material (RCM) ......................................................................... 17
6.2.4 Structural Fill .......................................................................................................................... 17
6.2.4.1 Materials ............................................................................................................................. 17
6.2.4.2 Placement .......................................................................................................................... 18
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6.2.4.3 Compaction ........................................................................................................................ 18
6.2.4.4 Subgrade Verification and Compaction Testing ................................................................ 19
6.2.5 Wet Weather Construction ..................................................................................................... 19
6.3 Temporary Slopes ...................................................................................................................... 19
6.4 Pavement Subgrade Preparation and Pavement Design Recommendations ........................... 20
6.5 Geotechnical Construction Monitoring ....................................................................................... 20
6.6 Use of Report ............................................................................................................................. 20
7.0 CLOSING ....................................................................................................................................... 21
8.0 REFERENCES ............................................................................................................................... 22
List of Tables (in text)
Table 3-1 Bedrock Depth in the Past and Recent Explorations Table 5-1 Allowable Axial Compressive and Uplift Capacity Values for Auger-Cast Piles
Table 5-2 LPILE Parameters for Auger-Cast Piles Table 5-3 Capillary Break Gradation
Table 6-1 Compaction Criteria
List of Figures
Figure 1 Vicinity Map Figure 2 Exploration Locations
List of Appendices
Appendix A Timber Pile Foundation for the Existing Cinema Building: Plan and Details Appendix B 1987 Borehole Logs
Appendix C Golder 2017 CPT Logs Appendix D Assessment of City of Renton Critical Areas Appendix E Liquefaction Assessment
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1.0 PROJECT INFORMATION AND SITE DESCRIPTION
This geotechnical report presents the results of Golder Associates Inc.’s (Golder’s) geotechnical
investigation for the proposed re-development at Via 405 Apartment building at 25 South Grady Way in
Renton, Washington (Site). The report was developed in general accordance with our proposal dated
January 4, 2017 for the field investigation and geotechnical services.
The Site consists of an existing cinema building situated on tax parcel # 7232000010 located just northeast
of the intersection of Interstate 405 and Highway 167. The parcel is bordered by a small creek (Rolling
Hills Creek) and Interstate 405 to the south and commercial property (parking lots and buildings) on the
north, east, and west sides. The site topography is flat and lies at approximately 28 feet. The location of
the Site is shown in Figure 1.
The existing cinema building was constructed around 1988 and contains a wood timber pile supported
structural slab foundation. The 8-inch diameter piles were driven to end bearing on bedrock at depths
ranging from about 15 to 48 feet below ground surface. The foundation plan of the cinema building as well
as the foundation detail drawings are shown in Figures A-1 and A-2 of Appendix A. As shown in
Figure A-2, the pile caps are 1.5 to 4 feet embedded below the floor slab. The building is surrounded by
asphalt paved parking and driveways.
The proposed apartment building will be constructed on the footprint of the existing cinema which will be
demolished. The apartment building footprint is slightly larger particularly on the east side. The building is
roughly rectangular shaped with a bevel cut out of the northeast corner due to constraints from an overhead
powerline easement. The building will contain a two level concrete parking podium with six levels of wood-
frame residential units above. The residential units will wrap around a central courtyard. No below grade
structures are planned.
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2.0 FIELD EXPLORATIONS, LABORATORY AND IN-SITU TESTING
Golder reviewed the previous geotechnical reports by GeoEngineers in 1987 and 1988. The previous
geotechnical explorations were conducted for the construction of existing cinema building and consisted of
drilling four boreholes. Boreholes B-1 to B-4 located on the north, east, and south sides of the Site were
drilled on July, 3, 6, and 7, 1987 to bedrock at depths ranging from 13 to 48 feet below grade. Location of
the boreholes are shown in Figure 2. The boreholes were advanced using a truck mounted, continuous-
flight, hollow stem auger drill and split spoon sampler was driven into soil with a 300-pound hammer free-
falling 30 inches to conduct Standard Penetration Testing (SPT) and obtain split spoon samples.
GeoEngineers did moisture content and dry density testing on selected samples. Observations of
groundwater were made during drilling and standpipe piezometers were installed in all explorations to
monitor groundwater level following drilling as well. Boring logs and a description of drilling and sampling
are provided in Appendix B.
For the current development plan, Golder contracted InSitu Engineering to conduct four Cone Penetration
Tests (CPTs) to supplement the 1987 boreholes. A CPT is a small diameter steel probe pushed down
through the soil column. It collects data on soil properties at 10 centimeter (cm) intervals and is commonly
used in loose soils to assist in liquefaction assessments and for ground improvement designs. The four
CPT explorations, referred to as CPT-01 to -04, were completed on February 15, 2017 and advanced to
the bedrock surface with variable depths ranging from 17.5 to 31 feet below grade. Locations of the Golder
CPTs are shown in Figure 2 as well. CPT logs including the cone tip resistance, the friction ratio (i.e. ratio
of cone side resistance to cone tip resistance), recorded pore pressure, the interpreted soil behavior, and
equivalent SPT blow counts are provided in Appendix C.
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3.0 SUBSURFACE CONDITIONS
3.1 Soil Conditions
The general soil profile at the Site consists of fill of less than 7 feet, underlain by alluvial deposits and
bedrock. The site soils are described further as follows:
Fill – Fill was found in the 1987 boreholes and also observed in Golder 2017 CPTs with
variable thickness of 2.5 to 7 feet. Fill soils generally consisted of medium dense to dense sand with trace of silt and gravel.
Alluvial Deposits – Alluvium was found directly below the fill. Based on our CPT the alluvium consists of silt and organic silt with the variable thickness of 6 feet in CPT-01,
0.5 feet in CPT-02, 9 feet in CPT-03, and 12 feet in CPT-04. The silty layer is soft to firm in CPT-01 and CPT-04 on the south and north sides of the Site and stiff to very stiff in
CPT-03 on the east side of the Site. (As it will be discussed in detail in the subsequent sections of the report, this layer is not liquefiable except for an interbedded 3-feet thick
sandy layer observed in CPT-03.) The silt layer is overlaying a medium dense sand/silty sand layer with varying thickness of 5 feet in CPT-03 to 12 feet in CPT-01, -02, and -03.
Except for CPT-03, interbedded silt layers have also been identified in the bottom 4 feet of this layer. As it will be discussed in the next sections, this layer is susceptible to seismic
liquefaction. The alluvial deposit is underlain with varying thickness of highly weathered sandstone in the form of medium dense to very dense fine or fine to medium sand. The
thickness is variable from 0.2 feet in CPT-04 to 7 feet in CPT-03. The medium dense sections in this layer is liquefiable. The CPT subsurface profile is reasonably consistent
with the general subsurface profile inferred from the previous 1987 boreholes.
Bedrock – Moderately hard sandstone was encountered at depths ranging from 13 to about
48 feet below grade, generally sloping down from southeast to northwest of the Site. The location of bedrock in our CPTs is generally consistent with the 1987 boreholes. The depth
of bedrock encountered in explorations is shown in Table 3-1.
3.2 Groundwater Conditions
Groundwater conditions were evaluated based on 1987 groundwater measurements in the four stand pipe
piezometers installed in the boreholes. Groundwater levels were measured at 11, 8.5, 8.5 and 5.5 feet
below ground surface in boreholes B-1, 2, 3, and 4, respectively, on July 14, 1987. Golder relied on the
groundwater information from the 1987 investigation, since the CPT data was inconclusive to determine
groundwater level. Please note that groundwater measurements were conducted in dry season and
fluctuations in the ground water levels should be expected due to changes in precipitation, season, and
other factors.
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3.3 Bedrock Depth
Table 3-1 summarizes the depth of bedrock observed in the 1987 and 2017 geotechnical explorations. The
bedrock depths are also depicted for each exploration on the exploration plan in Figure 2.
Table 3-1: Bedrock Depth in the Past and Recent Explorations
Exploration
Approximate
Depth to Bedrock (ft below grade)
1987 Boreholes
B-1 48
B-2 27
B-3 30
B-4 14
2017 Golder CPTs
CPT-01 23.5
CPT-02 17.5
CPT-03 26
CPT-04 31
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4.0 CRITICAL AREAS ASSESSMENT
Following the Renton Municipal Code Ordinance 5832, Section 4-3-050, the City of Renton requires the
geotechnical critical areas to be assessed as part of new project geotechnical submittals. Critical areas
include steep slopes, landslides, seismic liquefaction, severe erosion, flooding, aquifer recharge areas, and
abandoned coal mine hazards. We understand that other consultants will be tasked with completing a flood
study and an assessment of wetlands and streams. Following our proposal for geotechnical services,
Golder’s scope included an assessment of severe erosion, steep slopes, landslides, aquifer recharge areas,
abandoned coal mine, and seismic liquefaction hazard areas.
4.1 Severe Erosion
Section 4-3-050, Ordinance 5832 of the Renton Municipal Code defines two levels of low (EL) and high
(EH) erosion hazard. As shown in Figure D-1 in Appendix D, the Via 405 Site is located in the Low Erosion
Hazard (EL) zone. No erosion mitigation is required for this designation.
4.2 Steep Slopes
The closest steep slope to the Via 405 Site is the slope of the Rolling Hills Creek located on the south side
of the Site with an average slope of about 50 percent and vertical rise of 7 feet. According to the Renton
Municipal Code definitions, this slope is categorized as a “sensitive” steep slope (i.e. average slope ≥
40 percent and a vertical rise less than 15 feet). The code does not specifically require any critical area
buffer or structure setbacks for this slope designation, likely because of the limited slope height. However,
it refers to the adopted building code requirements. International Building Code or IBC (2015) requires a
clearance of the face of building footing to the slope more than the minimum of 40 feet and H/3, where H is
the slope height. This requirement is also met since the proposed building at its nearest distance is 38 feet
from the creek slope and the slope height is 8 feet. The location of the Site is also shown in the City of
Renton map with respect to the steep slopes in Figure D-2 of Appendix D.
4.3 Landslides
Section 4-3-050, Ordinance 5832 of the Renton Municipal Code defines four levels of low (LL), medium
(LM), high (LH), and very high (LV) landslide hazard zones. As shown in Figure D-3 of Appendix D, the
Site is located in the Low Landslide Hazard (LL) zone. No mitigation is required for landslide hazards for
low hazard designation.
4.4 Wellhead Protection Areas
Wellhead Protection Areas are the portion of an aquifer within the zone of capture and recharge area for a
well or well field owned or operated by the City. Section 4-3-050, Ordinance 5832 of the Renton Municipal
Code designates three Wellhead Protection Area Zones. The location of the Site is shown in the City of
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Renton map with respect to aquifer protection zones in Figure D-4 of Appendix D. As shown in the map,
the Site is not located in any of the Wellhead Protection Area Zones.
4.5 Abandoned Coal Mine
Section 4-3-050, Ordinance 5832 of the Renton Municipal Code defines three zones of low (CL), medium
(CM), and high (CH) hazard regarding the abandoned coal mines. According to the code, areas with no
known mine workings and no predicted subsidence are defined as low coal mine hazard (CL) areas. As
shown in Figure D-5 of Appendix D, the Site is located in the low coal mine hazards (CL) area and is not
underlain by any known coal mines.
4.6 Seismic Hazards
Renton Municipal Code defines two zones with low (SL), and high (SH) hazard regarding the seismic
Hazards. Areas underlain by soft or loose, saturated soils with Site Classifications of E or F, as defined in
the IBC (2015) are defined with High Seismic Hazard (SH) level. Considering the subsurface explorations
and our liquefaction assessment, the Via 405 Site is in the High Seismic Hazard (SH) zone in case of no
ground improvement. We evaluated the potential seismic-induced geotechnical hazards at the proposed
site including surface rupture, liquefaction and induced settlement, lateral spreading, and seismically
induced landslides. Our review of these hazards is based upon the past and recent subsurface explorations
presented in this report, regional experience, and our knowledge of local seismicity.
4.6.1 Surface Rupture
The Site is located approximately 9 kilometers (km) (about 5.8 miles) south of the southern trace of Seattle
Fault zone, and approximately 35 km (about 22 miles) northwest of the Tacoma Fault zone (USGS 2008).
The probability of surface rupture induced by these faults and impacting the Site is low in our opinion.
4.6.2 Liquefaction and Induced Settlement
Strong ground shaking could trigger liquefaction: a rapid loss of soil shear strength and stiffness.
Liquefaction can induce ground settlement, loss of bearing support, flow failure, lateral spreading and sand
boils. Saturated very loose to medium dense, clean to moderately silty sands and low-plasticity silts below
the groundwater are susceptible to liquefaction.
Our liquefaction analyses were based on the current building code (IBC 2015), which specifies an
earthquake return period of 2,475 years. We used the PGA of 0.573 g with moment magnitude of 7 in our
liquefaction evaluation. Details on determination of Site Class and PGA will be presented in the subsequent
sections of the report. The groundwater levels in the CPT explorations were also assumed based on the
groundwater measurements in the adjacent 1987 boreholes: 8.5, 5.5, 7, and 10 feet below grade in
CPT-01 to 04, respectively.
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Golder performed the liquefaction assessment using LiquefyPro software (CivilTech 2011). LiquefyPro
evaluates liquefaction potential based on the empirical liquefaction assessment approach (Youd and Idriss
2001) and calculates the estimated liquefaction-induced settlement in soil deposits.
Profiles of liquefaction safety factor for our CPT explorations are presented in Figures E-1 to E-4. Our
evaluations indicated that liquefaction is likely to occur in the loose to medium dense sandy alluvial deposit
below groundwater level with in estimated settlement of 2.5 to 3.5 inches. Liquefaction profiles in Figures
E-1 to E-4 also show the profiles of estimated settlement.
4.6.3 Liquefaction-Induced Lateral Spreading
Liquefaction can induce lateral movement (lateral spreading) toward steep banks or slopes. The Via 405
Site is located close to a creek with a 7-foot high steep slope. However, the ground water level in the
explorations and the top elevation of liquefiable layers are generally lower than the bottom of the creek,
except for borehole B-4. In addition, the general grading of the entire Site dose not slope downward towards
the creek. Therefore, in our opinion the lateral spreading hazard and its impact on the building structure is
negligible.
4.6.4 Seismically Induced Landslides
As indicted in Section 4.3 of the report, the Site is located in the Low Landslide Hazard (LL) zone. Therefore,
the hazard associated with seismically induced landslide is low for this Site as well.
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5.0 ENGINEERING RECOMMENDATIONS
This section presents recommendations for the design of the proposed building.
5.1 Foundation Options and Recommendations
After reviewing the existing project information and the available subsurface data, we developed a
geotechnical project approach for foundation support for the new apartment building that would not require
the removal of the existing timber piles. In our approach, the piles would not be relied upon as structural
foundation bearing members for the new foundation. We propose two options for the new foundation: pile
supported foundation and spread footings with ground improvement.
5.1.1 Pile Supported Foundation: Auger-Cast Piles
An auger-cast (or continuous flight auger) pile is a mid-sized (typically 18 to 24 inches in diameter), drilled
and grouted as replacement pile and typically reinforced. Auger-cast piles are a good alternative to driven
piles due to the lower vibration and noise and more appropriate for urban areas. Auger-cast piles are
installed by continuously drilling down to the pile embedment depth with a plug at the tip of the auger. When
the pile reaches the designated embedment depth, the plug is removed and grout flows out of the auger
under pressure as the auger is extracted from the hole. To increase the uplift pile structural capacity, a
steel bar is usually inserted at the center of the pile and a steel cage is placed in the upper portion to provide
increased lateral resistance.
Auger-cast piles should extend at least 10 feet into the bedrock to provide sufficient lateral resistance during
seismic event. Table 5-1 summarizes our recommendations on the allowable axial compressive and uplift
capacity values for 18- and 24-inch diameter auger-cast piles. These recommendations are based on the
minimum embedment of 10 feet in the bedrock. Table 5-2 also summarizes the LPILE (EnSoft 2016)
parameters to evaluate the lateral resistance of auger-cast piles. The ground water level as well as
thickness of fill and alluvium is variable. Table 3-1 and Section 3.2 of the report provides the information
regarding the depth of the bedrock (i.e. thickness of fill and alluvium) and groundwater level in the site
explorations respectively. All this information is also summarized in Figure 2 as well.
Auger-cast pile foundations mitigate the excessive liquefaction induced total and differential settlement and
provide sufficient lateral resistance for the foundation during shaking. Its continuous installation method
also reduces the issues regarding drill hole stability in caving soils and improves the work speed. These
advantages make auger-cast piles a viable option for the Site.
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Table 5-1: Allowable Axial Compressive and Uplift Capacity Values for Auger-Cast Piles
Pile diameter (in) Compressive (kips) Uplift (kips)
18 200 90
24 300 120
Table 5-3: LPILE Parameters for Auger-Cast Piles
Geological
Unit
Total Unit Weight
Effective Unit Weight
Soil Type for LPILE
Friction Angle
(φ') Undrained Shear
Strength, (Su)
Soil subgrade
modulus (k)
Strain at 50%
Max. Stress, ε50 Static Post-Seismic Static Post-Seismic
----- pcf pcf ----- Degree psf pci -----
Fill and
Alluvium 120 57.6 Sand
(Reese) 30 16 ------- 20 10 -------
Bedrock 140 77.6
Stiff Clay
w/o Free Water
(Reese)
------- ------- 12000 ------- ------- 0.004
5.1.2 Shallow Foundations with ground improvement
Golder’s recommendation for foundations also includes the application of spread footings with ground
improvement elements installed to support shallow foundations of the new building and to meet bearing
capacity requirements as well as static and/or seismic induced settlement tolerances. Our recommended
approach would be to keep the existing piles (remove pile caps as needed) beneath the new apartment
building foundation. Due to the presence of liquefiable loose to medium dense sand and compressible
silt/organic silt deposits, ground improvement elements should be added to provide an improved zone of
soil capable of supporting the new foundation loads under static and seismic loading. The proposed soil
improvement should also limit the total and differential static settlement. This option should be more
economical than the auger-cast piles option.
The actual design of the ground improvement – including developing the design geotechnical
parameters - should be completed by the ground improvement contractor. The design by the
ground improvement should be reviewed by Golder and the structural engineer.
Presented below are preliminary design criteria that can be used for initial design.
Design isolated footings using an allowable bearing pressure of 6 kips per square foot (ksf).
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Design continuous footings using an allowable bearing pressure of 4 ksf.
The above bearing pressures should be considered gross bearing values.
The maximum allowable bearing pressures assume vertical loading conditions.
The values presented may be increased by one-third for short-term wind and seismic loading.
Continuous and isolated footings should be embedded at least 18 and 36 inches respectively below the adjacent finished grade.
The Minimum Footing Widths:
Perimeter Footings ................................................................................................... 4 feet
Interior Isolated Footings .......................................................................................... 6 feet
Static settlement (due to building loads):
Total Settlement ....................................................................................... less than 1 inch
Differential Settlement ........................................................................... less than 1/2 inch
Seismic or liquefaction-induced settlement (due to building loads):
Total Settlement ....................................................................................... less than 2 inch
Differential Settlement .............................................................................. less than 1 inch
Building foundations must resist lateral loads due to earth pressures, wind, and seismic events. For the
initial design purposes, these loads can be assumed to be resisted simultaneously by:
BASE FRICTION: For the ground improvement methods presented subsequently, a layer of gravel is typically placed beneath the shallow foundations. An allowable value of 0.35
can be assumed for base friction between the gravel layer and spread footings. This value includes a factor of safety of 1.5. The allowable base friction value may be increased by
one-third for the seismic loading.
PASSIVE RESISTANCE ON SIDES OF SHALLOW FOOTINGS: We understand that the
pile caps of the existing timber piles at the depth of 1.5 to 4 feet below floor slab should be removed. Therefore, we anticipate using the laid-back excavations to a maximum depth
of 4 to 5 feet to construct the shallow foundations. Structural fill should be placed between the sides of foundation and the sloped excavations and compacted according to our
recommendations in Section 5.4.1. For initial design purposes, we recommend that the allowable passive pressure be based on a fluid with a density of 400 pounds per cubic foot
(pcf) (including a factor of safety of 1.5) for footings embedded in the structural fill. The allowable passive value is based on the assumption that the footing subgrade is above the
regional groundwater table. The allowable passive resistance can be increased by one-third for seismic loading. Since some disturbance is likely to occur during construction, we
recommend the upper 1 foot of passive resistance be neglected.
General discussions are provided below for ground improvement options. During the final design phase of
the project, foundation support options should be reviewed with the project team to determine the preferred
foundation support alternative.
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5.2 Ground Improvement Options
Ground improvement is designed to improve the strength and deformation engineering properties of the
soil. Ground improvement can mitigate the adverse impacts of liquefaction through one or combination of
three mechanisms: 1) densifying the soil mass, 2) dissipating excess pore pressures, and 3) reinforcing the
soil mass. The appropriate method of ground improvement is related to the nature of the soil to be improved
(e.g. coarse grained, fine grained, highly organic, or a mixture of these different types of soil), the loads and
performance requirements of the structure slabs and foundations, the time and cost for improvement, and
other factors.
Ground improvement is typically designed and constructed by a specialty contractor familiar with ground
improvement and contracted via a design-build performance specification. The design-build approach is
generally preferable since the specialty contractor can customize the design of the ground improvement
system to optimize the use of available equipment with site soils and project performance requirements.
We recommend the specialty contractor be required to provide a performance-based design, sealed by an
experienced professional engineer licensed in the State of Washington, which meets the support and
settlement performance criteria provided in this report and in the final project plans and specifications. We
recommend that the owner, the project structural engineer, and Golder jointly review and approve the
ground improvement design specification and the design.
Golder contacted two recognized soil improvement contractors for a preliminary evaluation of the Site:
Hayward-Baker Inc. (HBI) and Geopier Foundation Co. NW (GFC).
Ground improvement contractors proposed three methods of ground improvement as most cost effective
and appropriate for the Site. These methods are briefly discussed below:
Rigid inclusions (RIs) consist of unreinforced lean concrete columns installed to transfer loads through weak soils to the bearing soil below the building foundation elements. Rigid
inclusions mainly “densify” and “reinforce” the compressible soils. Rigid inclusions are placed in a grid pattern to distribute the foundation loads and provide a “block” of a
composite soil and lean concrete material that will reduce the potential for differential settlement.
Advantages with the use of rigid inclusions include: 1) lean concrete columns are more economical than auger-cast piles (shorter length, no reinforcement, and allows for the use
of conventional spread footings/slabs-on-grade), 2) there is minimal disturbance and vibration of adjacent structures during installation, and 3) the technique produces minimal
soil waste to be disposed.
Rigid inclusions are constructed using similar techniques for installing auger-cast piles.
Typically a bottom-feed mandrel with a top-mounted vibrator is advanced through the weak strata to the underlying bearing stratum. Lean concrete is then pumped into the hole
through the auger tip as the auger is extracted out of the hole.
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In seismically active areas a single steel bar can be installed after the completion of
concrete placement. The steel bar prevents the concrete from crumbling during seismic shaking.
The layout/design of the rigid inclusions will be completed once the building design has been finalized. Here are some preliminary design information for the preliminary design
and pricing purposes:
- 18- to 24-inch-diameter columns
- load carrying capacities on the order of 100 to 200 kips per RI element
- 5- to 6-foot rigid inclusion spacing for spread and strip foundations
- No columns necessary below the slab-on-grade
- Rigid inclusions extending from the bottom of foundation elevation to the bedrock, with
a 6-inch gravel break layer between the footing base and top of the rigid inclusion
Rammed Aggregate Piers (RAPs, also known GeoPiers) consists of stiff aggregate piers
that reinforce fine grained soils and densify coarse grained deposits. The piers are often constructed using a bottom feed horizontally oscillating vibrator which is advanced to a
predetermined depth under its own weight and vibrations. The downhole vibrator is lowered vertically to the designed tip of the pier typically with a standard crane or large
excavator. Aggregate (new crushed stone or recycled concrete) is then injected into the hole and compacted in lifts by repeated penetrations with the vibrator. The vibratory energy
from the vibrator densifies the aggregate and any surrounding granular soil. The vibrator is raised and lowered several times to construct a compacted aggregate element of the
diameter required by the design. Due to the presence of soft silt/organic silt layer, the pier should also be grouted to avoid budging and subsequent settlement induced by loss of
aggregates in the soft deposit.
Diameters of 24 to 48 inches are common for RAPs. A net allowable bearing pressure of
6 ksf as well as total and differential settlements of 1 and 0.5 inch for shallow foundations at the project site could be achieved through this method. The RAP design will be highly
dependent on the allowable differential settlement performance criteria provided by the design team.
Grouted stone column combines the benefits of rigid inclusion and aggregate pier
systems. Similar to rigid inclusions, vibro-concrete columns transfer loads through weak
strata to a bearing underlying layer, using a combination of low strength concrete and stone aggregate backfill. Similar to aggregate piers, a bottom-feed down-hole vibratory probe is
advanced through the weak strata to the underlying firm stratum and granular bearing soils are densified by the vibrator. Cement and water are then mixed with stone aggregate and
the mixture is discharged from the base of the bottom feed tremie tube. The vibrator is raised and lowered several times to construct a cemented stone column with the required
design diameter. Diameters of 24 to 48 inches are common and load carrying capacities on the order of 100 kips are commonplace; however, significantly higher capacities are
also possible.
5.3 Seismic Design
The seismic design recommendations are presented below.
5.3.1 Site Class
We understand that the seismic design of the proposed development will be performed in accordance with
the 2015 International Building Code (IBC). IBC (2015) indicates that the Site Class shall be classified in
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accordance with Chapter 20 of American Society of Civil Engineers (ASCE) 7-10. Based on ASCE 7-10,
Section 20.3, any site with soils vulnerable to potential failure or collapse under seismic liquefaction is
considered Site Class F, which is the case for the Via 405 Site. ASCE 7-10 and IBC (2015) do not provide
site effect factors for site class F and require site response analysis to obtain seismic design parameters.
However, according to an exception in ASCE 7-10, for structures with fundamental periods equal or less
than 0.5 second, site response analysis is not required to determine spectral accelerations for liquefiable
deposits. Rather, a site class is permitted to be determined according to Section 20.3 of ASCE 7-10 based
on the soil properties (shear wave velocity, SPT blow counts, and/or undrained shear strength) of the top
100 feet and the corresponding site factors to be used to adjust the Site Class B spectral accelerations.
Given the number of stories and type of the building (i.e. eight story: two level concrete parking podium with
six levels of wood-frame structure), we expect the structure fundamental period to be higher than
0.5 second. However, this is the structural engineer’s responsibility to confirm the structure fundamental
period.
In case of using auger-cast piles, the “controlling” earthquake motion would be at the interface of the
liquefiable/soft soils with bedrock – corresponding to Site Class B or C. In other words, the effect of
liquefaction/soft soils should be negligible on the seismic design of the proposed building. In case of using
ground improvement, it is our professional opinion that the reduction of liquefaction potential and the
reinforcement effect due to installation of ground improvement would alter the site class from Site Class F
to roughly Site Class D.
Considering the above, we recommend the use of Site Class D – which is more conservative compared to
Site Classes B and C. Our evaluations for the site class was based on the soil properties using both
methods 2 and 3 in section 20.3.3 of ASCE 7-10.
5.3.2 Ground Motion Parameters
We obtained the seismic parameters using the United States Geologic Survey (USGS) application
(https://earthquake.usgs.gov/designmaps/us/application.php ), which provides values in accordance with
IBC (2015). All the IBC (2015) seismic values are developed based on USGS 2008 national hazard maps.
The basis of design for this code is two-thirds of the hazard associated with an earthquake with 2 percent
probability of exceedance in a 50-year time period, which corresponds to an average return period of
2,475 years. The ground motion parameters for Site Class B and the site location at Latitude 47.469 and
Longitude -122.214 are presented in below:
Maximum Considered Earthquake Spectral Acceleration at Short Periods (0.2-Second): Ss = 1.423 g
Maximum Considered Earthquake Spectral Acceleration at 1-Second Period: S1 = 0.535 g
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Peak Ground Acceleration for Site Class B:
PGA = 0.573 g
The above values should be adjusted for Site Class D as discussed above.
5.4 Slab Subgrade
Conventional slab-on-grade floors can be supported on a subgrade of the native bearing soils or on
structural fill placed and compacted as noted in the Earthworks section of this report (Section 6.2.4). Slab-
on-grade floors should not be founded on loose soils, or uncompacted fills. The slabs should be underlain
by a capillary break material consisting of at least 4 inches of clean, free draining sand and gravel or crushed
rock containing less than 3 percent fines passing the No. 200 sieve (based on the minus No. 4 sieve
fraction); meeting the specification in Table 5-3.
Table 5-3: Capillary Break Gradation
Sieve Size or diameter (inches) % Passing
1 100% passing
No. 4 0 - 20%
No. 200 0 - 3%
Vapor transmission through floor slabs is an important consideration in the performance of floor coverings
and controlling moisture in structures. Floor slab vapor transmission can be reduced through the use of
suitable vapor retarders, such as plastic sheeting placed between the capillary break and the floor slab,
and/or specially formulated concrete mixes. Framed floors should also include vapor protection over any
areas of bare soils, and adequate crawl space ventilation and drainage should be provided. The
identification of alternatives to prevent vapor transmission is outside of our expertise. A qualified architect
or building envelope consultant can make recommendations for reducing vapor transmission through the
slab, based on the building use and flooring specifications.
5.4.1 Structural Fill Placement and Compaction
Where needed, structural fill should be a granular soil (with less than 5 percent passing the No. 200 sieve)
that when placed and compacted will meet the required compaction specifications. Structural fill should be
placed in 8-inch (or less) loose lifts and compacted to at least 95 percent of maximum ASTM D1557 dry
density below all footings and within 3 feet of final grade in pavement areas. In addition, structural backfill
placed around footings should also be compacted to at least 95 percent of ASTM D1557. We recommend
a minimum dry density of 90 percent ASTM D1557 beneath floor slabs and other structural components,
such as utility service trenches, not underlying pavements or footings. Structural fill behind backfilled walls
should be compacted to 90 percent of ASTM D1557, provided the backfill is not supporting buildings and
is not within 3 feet of final grade in pavement areas. If density tests indicate that compaction is not being
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achieved due to moisture content, the fill should be scarified, moisture-conditioned to near optimum
moisture content, re-compacted, and re-tested, or removed and replaced.
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6.0 CONSTRUCTION CONSIDERATIONS
Geotechnical-related site construction would consist of demolition of the Cinema building, excavation and
removal of the existing timber pile caps, placing crushed rock or gravel-working mat as a platform for
construction equipment, construction of foundation support (i.e. auger-cast pile or ground improvement),
preparation of the building foundation and slab subgrades, backfilling foundation walls, and installing new
utilities. This section discusses selected elements of these construction issues.
6.1 Removal of Existing Pile Caps
As shown in the existing foundation plan and details (Figures A-1 and A-2 of Appendix A), the bottom of
the existing pile caps supporting the interior and perimeter columns and walls are generally 4 and 1.5 to
2 feet below the finished grade, respectively. The pile cap thickness is 1.5 feet in general. As mentioned
before, the plan is to remove the pile caps as needed. Therefore, excavation to 4 to 5 feet below finished
grade will be required to access the pile caps.
6.2 Earthworks
6.2.1 Subgrade and Foundation Preparation
Following the excavation of the fill material to expose and remove pile cap, the foundation subgrade will
likely encounter soft to stiff silt/organic silt based on the proposed existing finished floor elevation of the
building and the available subsurface information. After completing the construction of foundation support,
structural fill or recycled concrete should also be placed and compacted under the foundations, floor slabs,
and pavements.
Uncontrolled fill or any other loose, soft, disturbed, compromised material or water should be removed from
beneath foundations prior to placement of reinforcing bars and concrete. Uncontrolled fill may be left in
place beneath floor slabs and pavements if it can be compacted to a firm and unyielding condition as noted
in Section 6.2.4.
Exposed subgrades for footings, floor slabs, pavements, and other structures should be compacted with a
vibratory roller to a firm, unyielding state. Any localized zones of loose granular soils observed within a
subgrade should be compacted to a density appropriate for planned development. Any organic, soft, or
pumping soils observed within a subgrade should be over-excavated and replaced with a suitable structural
fill material. Unsuitable excavated materials should not be mixed with materials to be used as structural fill.
6.2.2 Use of Onsite Excavated Soil
The native alluvium soil is not considered suitable to use as structural fill. However, the excavated fill below
the slab on grade of the existing cinema building may be appropriate to use as structural fill provided it can
be placed and compacted near the optimum moisture content and in accordance with the compaction
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requirements presented in Section 6.4.2.3 of this report. If density tests indicate that compaction is not
being achieved due to moisture content, the reused material should be scarified and moisture-conditioned
to near optimum moisture content, re-compacted, and re-tested, or removed and replaced.
6.2.3 Use of Reclaimed Concrete Material (RCM)
Reclaimed concrete material (RCM) aggregates are considered by many specifying agencies to be
conventional aggregate. RCM should be processed to satisfy the conventional soil and aggregate physical
requirements for fill material. Prior to its use, any reinforcing steel must be removed. RCM should be
crushed and screened to satisfy AASHTO M145, and ASTM D2940 gradation requirements for fill
aggregates. The processed RCM may contain some reclaimed asphalt pavement (RAP), when the RCM
is derived from composite pavements. It is recommended that the RAP content in the RCM be limited to
20 percent to prevent a reduction in bearing strength due to the presence of RAP.
Due to their high angularity, additional compaction effort may be required to compact RCM to its maximum
density. The processor may be required to satisfy moisture content criteria according to AASHTO T99, in
order to achieve proper compactibility. This usually requires the addition of water during placement and
compaction. The same quality control test procedures (e.g. in-situ density testing using Rubber-Balloon,
Sand Cone, and Nuclear Methods) applied for conventional aggregate are also appropriate for fill
applications when using RCM.
The high alkalinity of RCM (pH greater than 11) can result in corrosion to aluminum or galvanized steel
pipes in direct contact with RCM and in the presence of moisture. To avoid corrosion problems, RCM
should not be placed in contact with aluminum or galvanized steel pipes. The issue of high alkalinity of
RCM may also impact the water quality of the water which is exposed to RCM. During the earthwork
construction, the affected water which has been exposed to RCM should be collected and treated to meet
the standard requirements for pH before being discharged. Caution is also warranted in locations subject
to wet conditions, as tufa-like precipitates (CaCO3) associated with the leachate from RCM may develop
upon exposure to the atmosphere.
6.2.4 Structural Fill
The term "structural fill" refers to any materials placed under foundations, floor slabs, pavements, backfill
for walls, and utility trench backfill. Golder’s conclusions and recommendations concerning structural fill
are presented in the following sections.
6.2.4.1 Materials
Structural fill should be free of organic and inorganic debris, near the optimum moisture content, and
capable of being compacted to the required specifications for application. Soils used for structural fill
generally should not contain any organic matter or debris or any individual particles greater than 6 inches
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in diameter depending on use. Typical structural fill materials include clean sand and gravel; well-graded
mixtures of sand and gravel (commonly called "gravel borrow" or "pit-run"); mixtures of silt, sand, and gravel;
crushed rock; quarry spalls; and controlled-density fill (CDF). If onsite soils do not meet the above criteria,
or cannot be reworked to a suitable condition, we recommend using imported granular fill consisting of
imported, clean, well-graded sand and gravel, such as “Gravel Borrow” per Washington State Department
of Transportation (WSDOT): 9-03.14(1) (WSDOT 2014). Other fill materials may be used with approval of
geotechnical engineer.
If imported material is needed for filling during wet weather, the project specifications should include
provisions for using imported, clean, well-graded sand and gravel, such as “Gravel Borrow” per WSDOT:
9-03.14, except that the percent passing the US No. 200 sieve should be no greater than 5 percent.
6.2.4.2 Placement
Fill should be placed in horizontal lifts not exceeding 8 inches in loose thickness, and each lift should be
thoroughly compacted with a mechanical compactor. Any structural fill placed beneath footings should
extend laterally outside of the footing base at a 1H:1V (Horizontal to Vertical) slope projected down and
away from the bottom footing edge. In areas of thick structural fill (i.e. thickness > about 3 feet) this
requirement may be relaxed with geotechnical engineer permission.
6.2.4.3 Compaction
Using the Modified Proctor test (ASTM D1557) as a standard, we recommend that structural fill used for
onsite applications be compacted to minimum densities presented in Table 6-1.
Table 6-1: Compaction Criteria
Fill Application % Minimum Compaction
Building pad 95
Footing subgrade or bearing pad 95
Slab-on-grade floor subgrade and subbase 95
Retaining wall footing subgrade 95
Concrete slab subgrades 95
Asphalt pavement base and subbase 95
Asphalt pavement subgrade 95
Retaining wall backfill 90
Footing and stemwall backfill 90
Landscaped Areas 85
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6.2.4.4 Subgrade Verification and Compaction Testing
All structural fill should be placed over firm, unyielding subgrades prepared in accordance with the
recommendations in this report. The condition of all subgrades should be verified by the geotechnical
engineer before filling or construction begins. Fill soil compaction should be verified by means of in-place
density tests performed per ASTM D6938 during fill placement as earthwork progresses.
Pavement and foundation subgrades should be maintained in a well compacted state and protected from
degradation prior to paving or placing concrete. Protection measures may include restricted traffic,
perimeter drain ditches, or placement of a protective gravel layer on the subgrade. Disturbed or wet areas
should be removed and replaced by suitably compacted structural fill.
6.2.5 Wet Weather Construction
Although feasible, earthwork construction during wet weather or rainy season will significantly increase
costs associated with offsite disposal of unsuitable excavated soils, amount of dewatering needed to reach
foundation elevations, increased control of surface water, and increased subgrade disturbance and need
for soil admixtures, geotextiles, or rock working mats.
For fill placement during wet-weather site work, we recommend using soils that have fines content of
5 percent or less (by weight).
6.3 Temporary Slopes
Safe temporary slopes are the responsibility of the contractor and should comply with all applicable
Occupational Safety and Health Administration (OSHA) and Washington Industrial Safety and Health Act
(WISHA) standards. Temporary, stable cut slopes less than 8 feet in height can generally be constructed
using the following recommendations:
Uncontrolled Fill and Native Alluvium – 1.5H:1V
As previously discussed, groundwater will may be encountered during construction. If temporary cuts
encounter groundwater seepage, they should be sloped at 2H:1V or flatter (as recommended by the
geotechnical engineer at the time of construction) to prevent significant caving or sloughing. Temporary
cuts in the looser granular materials are expected to have some raveling at the cut face. Temporary cut
slopes in granular soils may need to be laid back flatter than 1.5H:1V if a change in material type or debris
is encountered.
In the event that groundwater seepage is encountered during excavation, the contractor must install
temporary drainage measures to protect the cut face and prevent degradation of the excavation area until
permanent drainage measures can be constructed.
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6.4 Pavement Subgrade Preparation and Pavement Design Recommendations
The existing plans do not show the need for pavement. However, in the event some of the existing
pavement is damaged and needs to be replaced, we recommend that the new pavement section match the
adjacent paved sections. Golder can also provide recommendations for new pavement if needed based
on the traffic load demand of the section. Section 6.2.4.3 of this report includes the general preliminary
recommendations for compaction requirements of the asphalt pavement base, subbase, and subgrade.
6.5 Geotechnical Construction Monitoring
We recommend that a qualified geotechnical-engineering firm is onsite during critical aspects of the project.
This would include: foundation subgrade preparation. The geotechnical engineer of record will perform
the special inspection.
6.6 Use of Report
This report has been prepared exclusively for the use of RVA Cinema LLC, Parkway Capital, Inc. and their
consultants for the project site. We encourage review of this report by bidders and/or contractors as it
relates to factual data only. The conclusions and recommendations presented in this report are based on
the explorations and observations completed for this study, conversations regarding the existing site
conditions, and our understanding of the planned development. The conclusions are not intended nor
should they be construed to represent a warranty regarding the development, but they are included to assist
in the planning and design process.
Judgment has been applied in interpreting and presenting the results. Variations in subsurface conditions
outside the exploration locations are common in geologic condition, such as those encountered at the Site.
Actual conditions encountered during construction might be different from those observed in the
explorations. When the site project plans are finalized, we recommend that Golder be given the opportunity
to review the plans and specifications to verify that they are in accordance with the conditions described in
this report.
The explorations were advanced in general accordance with locally accepted geotechnical engineering
practice; subject to the time limits, and financial and physical constraints applicable to the services for this
project, to provide information for the areas explored. There are possible variations in the subsurface
conditions between the borehole locations and variations over time.
The professional services retained for this project include only the geotechnical aspects of the subsurface
conditions at the Site. The presence or implication(s) of possible surface and/or subsurface contamination
resulting from previous site activities and/or resulting from the introduction of materials from off-site sources
are outside the scope of services for this report and have not been investigated or addressed.
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7.0 CLOSING
We trust that this report meets your needs. If you have questions or comments, please contact us at
(425) 883-0777. We appreciate the opportunity to provide our services for this project.
GOLDER ASSOCIATES INC.
Hamidreza Nouri, PhD, PE James G. Johnson, LG, LEG Project Geotechnical Engineer Principal
HN/JGJ/ks
3/20/17
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8.0 REFERENCES
American Society of Civil Engineers (ASCE). 7-10. 2010.
CivilTech Software. LiquefyPro. 2011. Version 5.8a.
American Society for Testing and Materials (ASTM). 2010. Conshohocken PA: ASTM.
D1557 Laboratory Compaction Characteristics of Soil Using Modified Effort
D2940-92, Graded Aggregate Material for Bases and Subbases for Highways or Airports D6938 In-Place Density and Water Content of Soil and Soil-Aggregate by Nuclear Methods (Shallow
Depth) (2010)
Ensoft Inc. Software. LPile. 2016. Version 2016.9.08.
GeoEngineers. 1987. Geotechnical Engineering Services Report, Reconstruction of Renton Village Cinema, Renton, Washington. July 21, 1987.
GeoEngineers. 1988. Addendum Report, Additional Geotechnical Consultation, Renton Village Cinema Reconstruction, Renton, Washington. May 24, 1988.
International Building Code (IBC) 2015. International Code Council, Inc.
USGS. 2008. The 2008 Probabilistic Seismic Hazard Analysis (PSHA) Interactive Deaggregations Website.
https://geohazards.usgs.gov/deaggint/2008/, (accessed January, 2013).
Washington State Department of Transportation. (WSDOT). 2014. Standard Specifications for Road,
Bridge, and Municipal Construction. Publication Number: M 41-10.
Youd, T.L. and Idriss, I.M. 2001. Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER
and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils, ASCE, Journal of Geotechnical Engineering, Vol. 127, No.4, pp. 297-324.
FIGURES
CLIENT
CONSULTANT
PREPARED
DESIGN
PROJECT
APPROVED
TITLE
REVIEW
YYYY-MM-DD
PROJECT No.Rev.
G:\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\INDD\1771669_100_002.indd
PARKWAY CAPITAL
FIGUREPHASE
VICINITY MAP
VIA 405 APTS
100 11771669
REDMOND
2017-03-17
PROJECT LOCATION
CLIENT
CONSULTANT
PREPARED
DESIGN
PROJECT
APPROVED
TITLE
REVIEW
YYYY-MM-DD
PROJECT No.Rev.G:\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\INDD\1771669_100_013.inddPARKWAY CAPITAL
FIGUREPHASE
EXPLORATION LOCATIONS
VIA 405 APTS
100 21771669
REDMOND
2017-03-17
APPENDIX A
TIMBER PILE FOUNDATION FOR THE EXISTING CINEMA BUILDING: PLAN AND
DETAILS
CLIENT
CONSULTANT
PREPARED
DESIGN
PROJECT
APPROVED
TITLE
REVIEW
YYYY-MM-DD
PROJECT No.Rev.G:\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\INDD\1771669_100_011.inddPARKWAY CAPITAL
FIGUREPHASE
TIMBER PILE FOUNDATION PLAN OF EXISTING CINEMA BUILDING
VIA 405 APTS
100 A-11771669
REDMOND
2017-03-17
CLIENT
CONSULTANT
PREPARED
DESIGN
PROJECT
APPROVED
TITLE
REVIEW
YYYY-MM-DD
PROJECT No.Rev.G:\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\INDD\1771669_100_012.inddPARKWAY CAPITAL
FIGUREPHASE
DETAILS OF TIMBER PILE FOUNDATIONS OF EXISTING CINEMA BUILDING
VIA 405 APTS
100 A-21771669
REDMOND
2017-03-17
APPENDIX B
1987 BOREHOLE LOGS
APPENDIX C GOLDER 2017 CPT LOGS
CPT-01
CPT CONTRACTOR: In Situ EngineeringCUSTOMER: Golder IncLOCATION: RentonJOB NUMBER: 1771669
OPERATOR: MayfieldCONE ID: DDG1369TEST DATE: 2/15/2017 12:27:10 PMPREDRILL: Punched 1' with blank CPTBACKFILL: #8 BentoniteSURFACE PATCH: Concrete
COMMENT:
Depth(ft)
Tip Resistance (Qt)(TSF)
0 5000
5
10
15
20
25
30
35
Friction Ratio (Fs/Qt)(PERCENT)
0 20
Pore Pressure (U2)(PSI)
-15 20
Soil Behavior Type(UNITLESS)
1 sensitive fine grained 2 organic material 3 clay
4 silty clay to clay 5 clayey silt to silty clay 6 sandy silt to clayey silt
7 silty sand to sandy silt 8 sand to silty sand 9 sand
10 gravelly sand to sand 11 very stiff fine grained (*) 12 sand to clayey sand (*) *SBT/SPT CORRELATION: UBC-1983
0 12
SPT Correlation(UNITLESS)
0 70
CPT-02
CPT CONTRACTOR: In Situ EngineeringCUSTOMER: Golder IncLOCATION: RentonJOB NUMBER: 1771669
OPERATOR: MayfieldCONE ID: DDG1369TEST DATE: 2/15/2017 1:13:28 PMPREDRILL: Punched 1' with blank CPTBACKFILL: #8 BentoniteSURFACE PATCH: Concrete
COMMENT:
Depth(ft)
Tip Resistance (Qt)(TSF)
0 5000
5
10
15
20
25
30
35
Friction Ratio (Fs/Qt)(PERCENT)
0 20
Pore Pressure (U2)(PSI)
-15 20
Soil Behavior Type(UNITLESS)
1 sensitive fine grained 2 organic material 3 clay
4 silty clay to clay 5 clayey silt to silty clay 6 sandy silt to clayey silt
7 silty sand to sandy silt 8 sand to silty sand 9 sand
10 gravelly sand to sand 11 very stiff fine grained (*) 12 sand to clayey sand (*) *SBT/SPT CORRELATION: UBC-1983
0 12
SPT Correlation(UNITLESS)
0 70
CPT-03
CPT CONTRACTOR: In Situ EngineeringCUSTOMER: Golder IncLOCATION: RentonJOB NUMBER: 1771669
OPERATOR: MayfieldCONE ID: DDG1369TEST DATE: 2/15/2017 11:33:09 AMPREDRILL: Punched 1' with blank CPTBACKFILL: #8 BentoniteSURFACE PATCH: Concrete
COMMENT:
Depth(ft)
Tip Resistance (Qt)(TSF)
0 5000
5
10
15
20
25
30
35
Friction Ratio (Fs/Qt)(PERCENT)
0 20
Pore Pressure (U2)(PSI)
-15 20
Soil Behavior Type(UNITLESS)
1 sensitive fine grained 2 organic material 3 clay
4 silty clay to clay 5 clayey silt to silty clay 6 sandy silt to clayey silt
7 silty sand to sandy silt 8 sand to silty sand 9 sand
10 gravelly sand to sand 11 very stiff fine grained (*) 12 sand to clayey sand (*) *SBT/SPT CORRELATION: UBC-1983
0 12
SPT Correlation(UNITLESS)
0 70
CPT-04a
CPT CONTRACTOR: In Situ EngineeringCUSTOMER: Golder IncLOCATION: RentonJOB NUMBER: 1771669
OPERATOR: MayfieldCONE ID: DDG1369TEST DATE: 2/15/2017 10:38:15 AMPREDRILL: Punched 1' with blank CPTBACKFILL: #8 BentoniteSURFACE PATCH: Concrete
COMMENT:
Depth(ft)
Tip Resistance (Qt)(TSF)
0 5000
5
10
15
20
25
30
35
Friction Ratio (Fs/Qt)(PERCENT)
0 20
Pore Pressure (U2)(PSI)
-15 20
Soil Behavior Type(UNITLESS)
1 sensitive fine grained 2 organic material 3 clay
4 silty clay to clay 5 clayey silt to silty clay 6 sandy silt to clayey silt
7 silty sand to sandy silt 8 sand to silty sand 9 sand
10 gravelly sand to sand 11 very stiff fine grained (*) 12 sand to clayey sand (*) *SBT/SPT CORRELATION: UBC-1983
0 12
SPT Correlation(UNITLESS)
0 70
APPENDIX D ASSESSMENT OF CITY OF RENTON CRITICAL AREAS
CLIENT
CONSULTANT
PREPARED
DESIGN
PROJECT
APPROVED
TITLE
REVIEW
YYYY-MM-DD
PROJECT No.Rev.FIGUREPHASE
G:\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\INDD\1771669_100_001.inddMAP OF CITY OF RENTON CRITICAL AREAS: SEVER EROSION
PARKWAY CAPITAL VIA 405 APTS
100 D-11771669
REDMOND
2017-03-17
CLIENT
CONSULTANT
PREPARED
DESIGN
PROJECT
APPROVED
TITLE
REVIEW
YYYY-MM-DD
PROJECT No.Rev.G:\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\INDD\1771669_100_003.inddFIGUREPHASE
MAP OF CITY OF RENTON CRITICAL AREAS: STEEP SLOPES
PARKWAY CAPITAL VIA 405 APTS
100 D-21771669
REDMOND
2017-03-17
CLIENT
CONSULTANT
PREPARED
DESIGN
PROJECT
APPROVED
TITLE
REVIEW
YYYY-MM-DD
PROJECT No.Rev.G:\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\INDD\1771669_100_004.inddFIGUREPHASE
MAP OF CITY OF RENTON CRITICAL AREAS: LANDSLIDES
PARKWAY CAPITAL VIA 405 APTS
100 D-31771669
REDMOND
2017-03-17
CLIENT
CONSULTANT
PREPARED
DESIGN
PROJECT
APPROVED
TITLE
REVIEW
YYYY-MM-DD
PROJECT No.Rev.G:\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\INDD\1771669_100_005.inddFIGUREPHASE
MAP OF CITY OF RENTON CRITICAL AREAS:
WELLHEAD PROTECTION AREAS
PARKWAY CAPITAL VIA 405 APTS
100 D-41771669
REDMOND
2017-03-17
CLIENT
CONSULTANT
PREPARED
DESIGN
PROJECT
APPROVED
TITLE
REVIEW
YYYY-MM-DD
PROJECT No.Rev.G:\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\INDD\1771669_100_006.inddFIGUREPHASE
MAP OF CITY OF RENTON CRITICAL AREAS:
ABANDONED COAL MINE
PARKWAY CAPITAL VIA 405 APTS
100 D-51771669
REDMOND
2017-03-17
APPENDIX E
LIQUEFACTION ASSESSMENT
CLIENT
CONSULTANT
PREPARED
DESIGN
PROJECT
APPROVED
TITLE
REVIEW
YYYY-MM-DD
PROJECT No.Rev.G:\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\INDD\1771669_100_007.inddLiquefyPro CivilTech Software USA www.civiltech.comLIQUEFACTION ANALYSIS
Via 405 Project
Liquefaction Assessment: PGA=0.573; M=7 Plate A-1
Hole No.=CPT-01 Water Depth=8.5 ft Surface Elev.=28 Magnitude=7Acceleration=0.573g
(ft)0
5
10
15
20
25
30
35
17.3 1.45 120 NoLq17.3 1.45 120 29.6517.3 2.27 120 31.9617.3 1.39 120 33.6817.3 1.91 120 31.46185.6 2.48 135 2.42305.2 3.48 135 0.79274.5 3.23 135 1.13231.9 3.41 135 2.67203.4 3.1 135 3.24188.6 1.82 135 1.51166.2 1.41 135 1.33150.4 1.22 135 1.56135.2 1.02 135 1.78115.8 0.88 135 2.49106.7 0.89 135 3.4196.5 0.88 129 4.5572.6 0.77 132 6.9362.4 0.59 129 7.5453.8 0.61 127 9.9942.7 0.64 130 14.08340.61 125 18.0832.1 0.37 128 15.05460.33 127 9.1555.3 0.34 128 7.2449.4 0.49 130 10.7631.9 0.58 130 19.8722.3 0.57 130 28.1121.7 0.54 130 29.2321.9 0.58 130 30.0420.5 0.44 128 29.2415.9 0.39 124 NoLq11.9 0.31 124 NoLq10.1 0.31 114 NoLq6.1 0.27 116 NoLq6.9 0.21 119 NoLq5.9 0.11 109 NoLq4.1 0.1 109 NoLq3.9 0.11 109 NoLq3.9 0.12 109 NoLq3.9 0.11 106 NoLq3.4 0.17 120 NoLq9.9 0.22 120 NoLq7.6 0.2 108 NoLq3.9 0.14 108 NoLq4.2 0.14 112 NoLq6.4 0.19 110 NoLq5.4 0.19 112 NoLq6.6 0.18 120 NoLq7.6 0.2 112 NoLq6.2 0.18 121 NoLq9.6 0.21 125 NoLq34.9 0.35 125 NoLq22.1 0.38 129 NoLq16.4 0.58 120 NoLq21.4 0.98 120 NoLq201.25 120 NoLq19.3 1.36 120 NoLq23.2 1.09 130 NoLq33.9 0.63 125 NoLq40.8 0.31 125 14.6540.5 0.3 124 14.2535.1 0.21 124 14.2934.9 0.12 123 12.0032.9 0.12 124 12.8435.3 0.29 126 16.4044.9 0.38 125 14.1949.5 0.26 125 10.51530.14 125 7.0751.4 0.11 124 6.8146.7 0.12 123 8.1243.4 0.14 123 9.5742.6 0.14 123 9.9543.1 0.17 124 10.5845.7 0.2 124 10.5250.5 0.21 125 9.4855.3 0.22 126 8.4462.8 0.16 127 6.0470.6 0.19 127 5.3570.1 0.25 126 6.3066.3 0.22 126 6.6060.8 0.27 125 8.2559.1 0.26 125 8.6153.7 0.24 125 9.4758.6 0.27 125 8.97590.25 126 8.5463.7 0.27 126 7.9565.5 0.35 126 9.0062.6 0.51 127 11.5660.2 0.55 127 12.8660.2 0.58 126 13.1962.5 0.54 127 12.1875.4 0.7 126 11.0771.4 0.58 126 10.6669.8 0.56 126 10.8972.3 0.71 128 12.0567.9 0.94 128 14.8866.2 0.68 127 13.3055.8 0.66 126 15.3266.7 0.56 128 11.7189.4 0.78 128 9.4786.6 0.51 130 7.65106.7 0.83 129 7.74100.1 1.1 128 10.1190.8 1.06 127 11.1886.2 0.42 127 7.1979.4 0.31 126 6.6670.9 0.41 126 9.18730.36 126 8.1476.9 0.28 125 6.7360.5 0.22 127 8.8027.6 0.34 125 25.6525.9 0.51 124 31.5422.6 0.45 124 34.6618.2 0.54 120 NoLq200.89 130 NoLq43.8 1.15 130 28.3848.3 1.2 126 26.0827.8 0.72 123 34.4122.7 0.4 122 33.45220.47 120 74.5528.3 1.53 130 NoLq46.9 1.72 130 31.5151.4 1.32 130 26.2540.7 1.18 130 30.3039.7 1.62 135 35.04123.1 2.58 135 14.741824.65 135 13.21242.6 6.4 130 11.971665.8 135 16.711904.93 135 13.34203.2 4.54 135 11.57182.9 4.94 130 13.89118.1 4.69 140 21.6280.6 3.96 130 27.251183.18 130 18.1577.8 2.46 130 23.3449.7 1.45 125 27.2652.9 0.97 126 22.5255.1 1.11 130 22.5465.2 2.43 140 27.8481.9 4.03 135 27.16170.9 4.39 135 13.50397.9 4.37 130
Raw Unit Fines qc fc Weight %Shear Stress Ratio
CRR CSR fs1Shaded Zone has Liquefaction Potential
0 1 Soil DescriptionFactor of Safety051 Settlement
SaturatedUnsaturat.
S = 2.84 in.
0 (in.)10
fs1=1.20
FIGUREPHASE
PROFILE OF LIQUEFACTION SAFETY FACTORS AND INDUCED SETTLEMENT: GOLDER CPT-01
PARKWAY CAPITAL VIA 405 APTS
100 E-11771669
REDMOND
2017-03-17
CLIENT
CONSULTANT
PREPARED
DESIGN
PROJECT
APPROVED
TITLE
REVIEW
YYYY-MM-DD
PROJECT No.Rev.G:\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\INDD\1771669_100_008.inddLiquefyPro CivilTech Software USA www.civiltech.comLIQUEFACTION ANALYSIS
Via 405 Project
Liquefaction Assessment: PGA=0.573; M=7 Plate A-1
Hole No.=CPT-02 Water Depth=5.5 ft Surface Elev.=28 Magnitude=7Acceleration=0.573g
(ft)0
5
10
15
20
25
30
35
22.9 .76 130 NoLq22.9 0.76 130 NoLq22.9 0.76 130 NoLq22.9 0.76 128 NoLq16.9 0.54 120 NoLq191.76 130 NoLq72.5 3.27 135 NoLq294.7 3 135 0.452912.44 135 0.00296.9 2.77 135 0.212802.66 135 0.47239.6 1.99 135 0.37194.3 1.68 135 0.951700.76 135 0.00181.9 2.31 135 3.41144.1 2.33 135 5.9399.2 1.88 135 8.7790.2 1.29 132 7.8684.8 1.04 129 7.29710.67 131 7.0560.8 0.64 130 9.3252.7 1.41 127 17.80450.82 130 16.2928.7 0.6 130 21.8422.6 0.44 126 25.0415.2 0.37 126 33.5115.6 0.41 130 31.5257.2 0.82 131 13.3460.6 1.01 133 13.4366.8 0.95 129 11.5771.5 0.78 131 9.6161.1 0.79 130 11.9847.3 0.92 130 17.8536.4 0.7 130 20.5731.9 0.51 130 20.5927.3 0.32 128 19.8522.1 0.23 126 21.4319.2 0.17 128 21.8719.6 0.12 122 19.26210.11 121 17.3921.7 0.1 121 16.4221.9 0.12 125 17.4219.6 0.13 125 19.9218.9 0.11 127 19.7919.6 0.14 127 20.5819.7 0.1 121 18.55210.09 121 16.8022.5 0.1 130 16.46250.23 130 19.9226.3 0.36 124 22.2331.1 0.24 126 16.04390.13 124 9.5142.4 0.09 124 7.3241.2 0.12 126 8.55370.31 124 14.8332.6 0.34 126 17.6136.7 0.3 126 15.0439.4 0.25 125 12.68340.23 130 14.92290.35 125 20.1334.3 0.27 125 15.9834.6 0.34 129 17.3325.7 0.44 130 25.4427.9 0.43 130 24.6130.4 0.66 130 26.7230.1 0.63 130 26.6231.7 0.68 130 26.4332.3 0.81 130 27.7543.4 1.24 130 25.7151.1 1.32 132 22.3277.1 1.5 127 16.0953113019.0928.4 0.73 127 29.5323.7 0.38 128 28.1025.2 0.46 128 28.2625.6 0.47 128 28.20790.75 130 10.6246.5 0.9 130 20.5332.5 1.01 130 30.6431.2 0.73 130 28.4331.1 0.67 130 27.9230.5 0.86 120 32.0433.7 2.08 120 NoLq38.6 2.22 130 36.5146.1 1.5 130 28.3637.5 1.03 130 28.0433.9 0.58 129 24.1829.6 0.47 130 25.4030.8 0.61 130 27.4435.5 1.08 130 30.55471.79 130 29.5257.7 1.75 130 24.8645.5 1.44 130 27.7535.1 1.01 129 30.2331.2 0.68 129 28.6731.5 0.67 128 28.5127.9 0.73 130 31.96370.72 130 25.3438.9 0.83 130 25.7533.2 0.9 130 30.3738.3 1.2 127 30.5157.9 1.17 132 19.72116.8 1.34 135 9.42132.2 1.45 135 8.01159.3 2.2 135 8.29201.4 3.16 135 7.79252.2 3.87 135 6.50327.2 4.64 130 4.90
Raw Unit Fines qc fc Weight %Shear Stress Ratio
CRR CSR fs1Shaded Zone has Liquefaction Potential
0 1 Soil DescriptionFactor of Safety051 Settlement
SaturatedUnsaturat.
S = 2.58 in.
0 (in.)10
fs1=1.20
FIGUREPHASE
PROFILE OF LIQUEFACTION SAFETY FACTORS AND INDUCED SETTLEMENT: GOLDER CPT-02
PARKWAY CAPITAL VIA 405 APTS
100 E-21771669
REDMOND
2017-03-17
CLIENT
CONSULTANT
PREPARED
DESIGN
PROJECT
APPROVED
TITLE
REVIEW
YYYY-MM-DD
PROJECT No.Rev.G:\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\INDD\1771669_100_009.inddLiquefyPro CivilTech Software USA www.civiltech.comLIQUEFACTION ANALYSIS
Via 405 Project
Liquefaction Assessment: PGA=0.573; M=7 Plate A-1
Hole No.=CPT-03 Water Depth=7 ft Surface Elev.=28 Magnitude=7Acceleration=0.573g
(ft)0
5
10
15
20
25
30
35
6.4 .55 114 NoLq6.4 0.55 114 NoLq6.4 0.55 114 NoLq6.4 0.55 114 NoLq6.4 0.55 120 NoLq13.1 1.28 135 NoLq208.2 2.22 135 32.95303.6 3.2 135 0.47316.8 3.57 135 0.79277.3 3.03 135 1.02254.8 3.16 135 1.802252.41 135 1.55186.1 1.98 135 2.11145.8 1.45 135 2.76102.7 1.12 132 4.7861.8 0.91 130 9.84300.79 130 20.7923.4 0.66 120 26.3714.5 0.59 130 32.9718.8 0.78 120 32.0825.6 1.16 130 31.7327.5 0.3 135 15.34130.9 1.06 135 3.58113.9 2.1 130 8.9996.9 2.79 135 13.8987.9 2.07 130 13.18732.18 130 17.0058.4 1.73 135 18.1489.3 1.34 130 NoLq40.3 1.26 130 NoLq35.6 1.1 130 NoLq28.1 1.04 130 NoLq19.3 0.8 120 NoLq14.5 0.66 120 NoLq13.6 0.59 120 NoLq11.4 0.52 120 NoLq10.4 0.46 119 NoLq9.5 0.42 117 NoLq8.7 0.64 130 NoLq28.9 1.1 130 NoLq341.49 120 NoLq28.5 1.5 120 NoLq27.9 1.44 120 NoLq26.6 1.49 120 NoLq25.8 1.46 120 NoLq25.5 1.25 130 NoLq26.2 1.14 120 NoLq20.9 1.15 120 NoLq17.5 1.06 120 NoLq17.7 1.16 120 NoLq20.2 1.04 120 NoLq17.6 0.97 130 NoLq22.1 0.55 127 30.8147.1 0.5 127 14.9549.7 0.58 130 15.0440.1 0.71 130 20.4136.1 0.54 130 20.81340.61 130 23.25340.49 124 21.1234.1 0.37 124 18.6233.8 0.24 124 15.6235.5 0.17 124 12.8834.8 0.17 125 13.0438.8 0.2 126 12.4239.7 0.23 126 12.8245.7 0.42 128 14.3355.7 0.63 125 13.8452.6 0.31 126 10.9622.6 0.36 126 NoLq18.7 0.41 130 NoLq18.5 0.68 130 NoLq25.8 0.91 130 NoLq31.1 0.98 130 NoLq34.3 1.17 130 NoLq35.8 1.08 130 NoLq36.4 1.42 130 NoLq37.6 1.75 130 NoLq41.6 1.97 130 NoLq37.3 1.75 120 NoLq37.2 1.81 130 NoLq46.5 1.74 120 NoLq38.6 2 120 NoLq32.3 2.21 120 NoLq41.2 2.09 130 NoLq32.3 1.21 120 NoLq271.29 130 NoLq351.23 128 32.2664.5 1.02 127 17.0857.8 0.76 127 15.3576.3 0.53 126 8.9054.2 0.42 123 12.2847.1 0.25 125 11.9342.9 0.23 125 12.9440.7 0.38 125 16.9842.1 0.46 126 17.8346.1 0.49 126 16.7146.9 0.39 126 14.7847.2 0.27 126 12.5845.6 0.3 124 13.87400.43 130 18.6337.1 0.59 124 23.03380.3 124 17.2540.9 0.23 124 14.3438.5 0.29 123 16.4635.4 0.17 124 14.7640.7 0.19 125 13.4045.9 0.37 125 14.9058.9 0.47 126 12.5772.7 0.62 128 11.3373.1 0.83 128 13.1273.4 1.09 130 15.17821.25 128 14.3992.9 1.21 131 12.03117.6 1.33 135 9.26154.4 1.64 135 7.08194.9 2.21 135 6.19227.1 2.77 135 5.94228.6 3.39 135 7.08229.3 3.92 135 7.98234.8 2.79 135 5.73245.9 2.92 135 5.37245.2 3.09 135 5.72254.8 3.33 135 5.81270.7 3.94 135 6.34264.9 5.11 135 8.31239.7 4.75 135 9.16203.8 4.27 135 10.58166.7 3.65 135 12.29141.7 3.22 135 13.871382.86 135 13.311402.87 135 13.14143.3 3.11 135 13.52133.1 3.17 135 14.91136.3 3.1 134 14.57112.5 2.89 135 16.89121.4 2.87 135 15.70138.3 2.69 134 12.89149.9 2.46 134 10.87151.7 1.99 135 9.35138.1 2.4 131 11.91131.1 1.76 128 10.56104.3 1.37 128 12.1779.7 1.45 126 16.9384.4 0.77 127 11.3287.6 0.35 127 6.9887.7 0.39 127 7.0786.5 0.48 126 8.1879.4 0.45 126 9.0077.2 0.48 125 10.01680.67 126 13.8155.2 0.53 125 15.8253.1 0.4 124 14.6160.4 0.43 128 13.3577.8 1.08 130 15.29126.2 1.47 134 9.79194.6 1.89 135 6.19220.4 2.7 135 6.57260.8 3.25 130
Raw Unit Fines qc fc Weight %Shear Stress Ratio
CRR CSR fs1Shaded Zone has Liquefaction Potential
0 1 Soil DescriptionFactor of Safety051 Settlement
SaturatedUnsaturat.
S = 2.50 in.
0 (in.)10
fs1=1.20
FIGUREPHASE
PROFILE OF LIQUEFACTION SAFETY FACTORS AND INDUCED SETTLEMENT: GOLDER CPT-03
PARKWAY CAPITAL VIA 405 APTS
100 E-31771669
REDMOND
2017-03-17
CLIENT
CONSULTANT
PREPARED
DESIGN
PROJECT
APPROVED
TITLE
REVIEW
YYYY-MM-DD
PROJECT No.Rev.G:\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\INDD\1771669_100_010.inddLiquefyPro CivilTech Software USA www.civiltech.comLIQUEFACTION ANALYSIS
Via 405 Project
Liquefaction Assessment: PGA=0.573; M=7 Plate A-1
Hole No.=CPT-04 Water Depth=10 ft Surface Elev.=28 Magnitude=7Acceleration=0.573g
(ft)0
5
10
15
20
25
30
35
52.7 .75 110 NoLq52.7 0.75 110 3.7052.7 0.75 110 4.9652.7 0.75 110 5.8452.7 0.75 110 6.5452.7 0.75 129 7.1252.7 0.75 135 6.811100.77 135 1.07107.9 0.76 135 1.43100.9 1.03 135 3.17110.4 0.78 133 1.8786.9 0.95 134 4.82930.6 134 2.5293.4 0.67 133 2.96880.83 132 4.7261.6 1.03 130 10.5457.7 1.22 135 12.50115.7 1.75 135 7.09109.8 2.48 130 10.2191.8 2.41 130 12.75942.71 135 13.39120.2 2.48 135 9.451211.83 135 7.15142.6 1.79 135 5.231882.26 135 3.97217.6 2.88 135 3.99203.6 3.15 135 5.13199.2 2.5 135 4.32195.9 2.83 135 5.16176.7 2.83 135 6.45133.1 3.04 130 10.651023.2 130 NoLq73.2 2.29 120 NoLq25.8 1.61 120 NoLq11.5 0.49 114 NoLq6.5 0.3 113 NoLq6.6 0.28 123 NoLq12.2 0.24 121 NoLq23.3 0.17 126 NoLq41.8 0.26 132 NoLq69.7 1.36 133 NoLq96.4 1.28 134 NoLq1051.37 135 NoLq84.5 1.23 129 NoLq56.1 1.02 130 NoLq27.1 0.94 120 NoLq17.1 0.76 127 NoLq14.5 0.57 120 NoLq13.1 0.53 119 NoLq10.9 0.46 117 NoLq90.4 115 NoLq8.9 0.32 119 NoLq8.5 0.24 111 NoLq6.3 0.22 111 NoLq6.2 0.19 119 NoLq7.1 0.2 113 NoLq7.8 0.29 119 NoLq10.8 0.24 122 NoLq18.7 0.29 124 NoLq16.8 0.35 122 NoLq14.7 0.25 122 NoLq27.3 0.25 126 21.4224.5 0.29 124 24.74200.28 124 28.9820.1 0.19 120 25.7716.5 0.17 118 30.1810.9 0.21 118 NoLq7.6 0.19 118 NoLq7.5 0.19 117 NoLq8.3 0.13 118 NoLq7.3 0.14 108 NoLq50.14 108 NoLq5.1 0.14 108 NoLq5.2 0.18 108 NoLq5.4 0.19 108 NoLq5.7 0.21 108 NoLq5.4 0.23 110 NoLq60.31 111 NoLq7.3 0.38 113 NoLq80.45 111 NoLq7.5 0.45 110 NoLq6.3 0.23 108 NoLq5.7 0.27 94 NoLq3.1 0.22 110 NoLq5.9 0.22 111 NoLq6.9 0.2 110 NoLq6.7 0.19 110 NoLq6.1 0.16 110 NoLq5.8 0.15 116 NoLq5.5 0.13 108 NoLq5.4 0.15 110 NoLq5.8 0.17 110 NoLq6.2 0.18 109 NoLq60.19 109 NoLq6.1 0.2 109 NoLq6.4 0.19 116 NoLq70.18 109 NoLq6.2 0.19 108 NoLq5.4 0.2 108 NoLq5.2 0.23 109 NoLq60.25 108 NoLq5.4 0.21 108 NoLq5.4 0.16 108 NoLq4.9 0.15 114 NoLq5.4 0.12 94 NoLq5.9 0.09 116 NoLq60.11 119 NoLq9.7 0.29 122 NoLq16.9 0.45 124 NoLq18.4 0.45 115 NoLq10.9 0.42 122 NoLq12.2 0.45 125 NoLq160.64 130 NoLq230.89 123 NoLq18.2 0.62 122 NoLq15.7 0.32 119 NoLq15.7 0.11 122 30.3821.4 0.16 118 24.9425.8 0.08 122 16.9046.1 0.14 122 10.6447.5 0.15 124 10.1956.9 0.24 125 9.77680.24 127 7.5282.2 0.27 127 5.9390.2 0.35 127 5.8784.4 0.44 126 7.5572.7 0.37 124 8.72590.32 123 11.3138.8 0.54 124 22.2740.3 0.43 126 18.9572.3 0.26 127 7.8881.5 0.33 126 6.9675.8 0.41 126 8.6974.7 0.28 126 7.35740.25 126 6.9177.8 0.23 126 6.1478.6 0.25 126 6.2775.6 0.18 125 5.8172.5 0.2 124 6.54600.19 123 8.5454.3 0.18 123 9.6754.1 0.23 122 10.9248.1 0.27 124 13.3357.5 0.28 124 11.0960.1 0.37 124 11.5860.1 0.2 126 8.9680.1 0.32 126 7.2480.1 0.34 127 7.4689.6 0.41 126 6.9095.4 0.31 126 5.32980.37 127 5.6390.5 0.4 126 6.7682.5 0.34 126 7.1384.7 0.25 126 5.8395.6 0.29 126 5.061060.3 126 4.30103.4 0.34 127 4.9899.8 0.66 127 8.1497.4 0.92 127 10.30102.2 0.92 126 9.45103.6 0.08 126 2.44106.2 0.51 120 6.64130.43 127 32.2594.5 0.75 125 10.5656.3 0.49 126 15.3030.6 0.45 122 27.4919.4 0.56 127 NoLq34.8 0.59 124 27.7448.7 0.77 130 22.6144.9 0.94 123 25.73430.53 125 21.6751.9 0.6 129 18.7038.1 0.63 127 26.2126.3 0.73 127 NoLq20.3 0.81 130 NoLq33.1 0.95 124 90.9050.7 0.67 125 20.5170.2 0.65 126 14.4363.1 0.98 130 19.2046.5 0.96 128 25.8437.6 0.99 130 32.4529.8 1.33 130 NoLq29.2 1.24 127 NoLq30.3 1.12 129 NoLq430.99 130 29.7537.2 1.32 130 NoLq441.67 130 NoLq46.5 2.28 130 NoLq82.3 3.52 135 27.19184.4 4.69 130
Raw Unit Fines qc fc Weight %Shear Stress Ratio
CRR CSR fs1Shaded Zone has Liquefaction Potential
0 1 Soil DescriptionFactor of Safety051 Settlement
SaturatedUnsaturat.
S = 3.21 in.
0 (in.)10
fs1=1.20
FIGUREPHASE
PROFILE OF LIQUEFACTION SAFETY FACTORS AND INDUCED SETTLEMENT: GOLDER CPT-04
PARKWAY CAPITAL VIA 405 APTS
100 E-41771669
REDMOND
2017-03-17
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1771669_parkway capital via 405 comment response_2017-06-12.docx
Golder Associates Inc.
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June 12, 2017 Project No. 1771669
Craig R. Koeppler Parkway Capital, Inc.
520 Pike Street, Suite 1500 Seattle, WA 98101
RE: INFILTRATION FEASIBILITY – VIA 405 APARTMENTS LUA17-000237, PPUD
Dear Craig:
This letter presents an assessment of infiltration feasibility at the proposed Via 405 Apartment Building located at 25 South Grady Way in Renton, Washington. This feasibility assessment is being submitted in
response to comments on the Planned Urban Development (PUD) application for the project, specifically comment #8 in the City of Renton’s letter to Craig Koeppler dated May 25, 2017. The comment requested
that the geotechnical engineer complete a feasibility assessment for on-site best management practices (BMPs) (stormwater infiltration for impervious surfaces). Stormwater infiltration feasibility includes an
assessment of several factors including soil permeability, thickness of unsaturated infiltration receptor soil, lateral continuity of permeable soil units, depth to seasonal high groundwater or low permeability restrictive
layers and civil stormwater constraints. A deficiency in any one of these factors can render stormwater infiltration infeasible or impractical. The results of our infiltration assessment are presented below.
Project Setting
The project site consists of an existing cinema building surrounded by asphalt parking lots in a commercial
business park (tax parcel # 7232000010) located just northeast of the intersection of Interstate 405 and Highway 167. The parcel is bordered by a small creek (Rolling Hills Creek) and Interstate 405 to the south
and commercial property (parking lots and buildings) on the north, east, and west sides. The site topography is fairly flat and lies at approximately 26 to 28 feet (Figure 1, Triad Plan).
The project site is located at the north end of a large alluvial floodplain extending from Lake Washington south to Auburn and west to the Duwamish Valley. The flood plain at the project site at the south end of
Lake Washington was shaped by the Cedar and Black Rivers. Historically the Cedar River flowed into the Black River with the confluence located about 1 mile north of the Via 405 site. The combined Black and
Cedar Rivers flowed west into the Duwamish River. Flooding was historically common at the confluence of the rivers with flood waters extending north to Lake Washington and for miles to the south resulting in
the deposition of thick alluvial deposits of silt sand and organics (peat). The historic flooding of the project area was initially reduced by dredging a new channel for the Cedar River to flow north into Lake
Washington. After the construction of the Hiram M. Chittenden Locks in 1916 the level of Lake Washington was lowered by about 9 feet resulting in the demise of the Black River. Site development has since occurred
in the floodplain aided by additional stormwater conveyance improvements to reduce the hazards of flooding.
Stormwater on and adjacent to the project site is conveyed to Rolling Hills Creek which flows west along the south boundary of the project site and then south below I-405 and Hwy 167 to its confluence with
Springbrook Creek. The channel elevation of Rolling Hills Creek adjacent to the project site is about 20 feet (Figure 2).
The parking lots surrounding the project site appear on the City of Renton Effective FEMA Flood Insurance Rate Map (City of Renton 2017). The location of the 100-year flood elevation can be seen more clearly on
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the Triad site plan (Figure 2) and includes most of the parking lot surrounding the project site. The flood
elevation shown on the Triad figure is 27.6 feet.
Geology and Soil Conditions
The site geologic conditions are described in borings at the site (GeoEngineers 1987) and on an adjacent site about 300 feet to the north (GeoEngineers 2005) (Figure 1). In general, the borings encountered sand
and silt alluvium over bedrock. The depth to bedrock ranges from about 15 to 40 feet below ground surface and increases to the north. The shallow soil conditions that would have a material impact on infiltration
feasibility are described below. Copies of the exploration logs are included in the Attachments A and B.
Fill – Fill of variable composition was described in all six borings on and adjacent to the site ranging in
thickness from 2 to 9 feet thick (four borings on-site and in two borings on an adjacent site to the north). The fill was described as fine to medium sand with trace silt or silty fine to medium sand.
Alluvium – The alluvium immediately below the fill was described as silt or silty fine sand with a variable amount of organics. The USCS symbol assigned was generally ML (Low plasticity silt). The alluvium
extends to bedrock at a depth of about 15 to 40 feet below ground surface at the subject site.
Groundwater
Groundwater below the project site occurs in a shallow unconfined alluvial aquifer recharged by
precipitation, stormwater runoff and groundwater from adjacent uplands and during flood events on the Cedar River and Rolling Hills Creek. The aquifer flow direction at the site is likely to the north toward Lake
Washington. Groundwater levels on and adjacent to the site were measured in monitoring wells installed in 1987 and 2005. The 1987 study at the subject site measured groundwater levels as shallow as elevation
21.5 feet (5.5 feet below ground surface) in the month of July. The 2005 study measured water levels at depths of 9.3 to 10.3 feet below ground surface in September when groundwater levels are near their
seasonal low. The study also stated that based on observations from other studies in the project area that “…the groundwater level could rise to within 5 feet of the existing ground surface during the normally wet
portions of the year” (GeoEngineers 2005).
Infiltration Assessment and Conclusions
As stated in the introduction, the feasibility of infiltrating stormwater even in shallow BMPs such as bioinfiltration facilities depends on several factors, only one of which is the infiltration rate of the underlying soil. For infiltration to be feasible, the infiltration receptor soil must have a sufficient vertical thickness and
lateral continuity without containing restrictive soil layers. Seasonal high groundwater levels must be low enough so that the facility can function when needed most, in the winter months. In our opinion, the subject site soil and groundwater conditions are not suitable for stormwater infiltration.
The shallow site soils contain non-engineered fill soils overlying alluvial silt. The description of the fill soil from the site explorations implies it may be permeable (sand with trace silt) and capable of supporting infiltration. However, fill soils do not meet the site suitability criteria (Section 3.3.7) in the 2012 Stormwater
Management Manual for Western Washington (Ecology 2012). The section states “Waste fill materials shall not be used as infiltration soil media nor shall such media be placed over uncontrolled or non-engineered fill soils.” In addition, horizontal continuity of the infiltration receptor layer is critical to avoid
mounding during infiltration. There is considerable variability in the observed fill thickness (2 to 9 feet) on
the subject site.
The fill is underlain directly by native alluvial deposits consisting of silt or sandy silt with organics classified as an ML. This deposit would be considered a low permeability restrictive layer that would impede
infiltration.
Infiltration facility designs require a minimum separation between the infiltration receptor layer (the elevation where the water is infiltrated) and the seasonal high groundwater level or a restrictive soil layer. Typically
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References
City of Renton (Renton). 2017. Effective FEMA Flood Insurance Map. Accessed online June 9, 2017. http://rentonwa.gov/uploadedFiles/Government/FIT/GIS/PDF_Files/Flood%20Hazard.pdf.
GeoEngineers. 1987. Geotechnical Engineering Services Report, Reconstruction of Renton Village Cinema, Renton, Washington. July 21.
GeoEngineers. 2005. Geotechnical Engineering Services, Proposed Storm Water Detention Vault, 375 South Grady Way, Renton Village Shopping Center, Renton, Washington. September 29.
Washington State Department of Ecology (Ecology). 2012. Stormwater Management Manual for Western Washington, Volume III Hydrologic Analysis and Flow Control BMP’s, December 2014. Accessed
online June 9, 2017. https://fortress.wa.gov/ecy/publications/parts/1410055part5.pdf.
FIGURES
ROLLING HILLS CREEK
01 in1771669
CONTROL
100
FIGURE
1A
2017-06-12
REDMOND
-
JGJ
JGJ
INFILTRATION FEASABILITY REPORT
VIA 405 APARTMENTS
RENTON, WA
PARKWAY CAPITAL
SITE VICINITY PLAN
TITLE
PROJECT NO.REV.
PROJECTCLIENT
CONSULTANT
PREPARED
DESIGNED
REVIEWED
APPROVED
YYYY-MM-DD
Path: \\redmond\geomat$\geomatics\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\DWG\ | File Name: 1771669_100_001.dwg | Last Edited By: eezzeddin Date: 2017-06-12 Time:1:59:22 PM | Printed By: EEzzeddin Date: 2017-06-12 Time:2:00:04 PMIF THIS MEASUREMENT DOES NOT MATCH WHAT IS SHOWN, THE SHEET SIZE HAS BEEN MODIFIED FROM: ANSI D1987 EXPLORATIONS
2005 EXPLORATIONS
BACKGROUND LAYOUT PROVIDED BY TRIAD ASSOCIATES, ON
JUNE 8TH, 2017, DELIVERED IN PDF FORMAT.
0
FEET
100 200
1'' = 100'
LEGEND REFERENCE(S)
0 1 in1771669CONTROL100FIGURE2A 2017-06-12REDMOND-JGJJGJINFILTRATION FEASABILITY REPORTVIA 405 APARTMENTSRENTON, WAPARKWAY CAPITALSITE PLAN-100 YEAR FLOOD PLAIN TITLEPROJECT NO.REV.PROJECTCLIENTCONSULTANTPREPAREDDESIGNEDREVIEWEDAPPROVEDYYYY-MM-DDPath: \\redmond\geomat$\geomatics\ParkwayCapital\405Appts\99_PROJECTS\1771669_RVA Cinema\100\02_PRODUCTION\DWG\ | File Name: 1771669_100_001.dwg | Last Edited By: eezzeddin Date: 2017-06-12 Time:1:59:22 PM | Printed By: EEzzeddin Date: 2017-06-12 Time:2:00:07 PM
IF THIS MEASUREMENT DOES NOT MATCH WHAT IS SHOWN, THE SHEET SIZE HAS BEEN MODIFIED FROM: ANSI D0FEET20 401'' = 20'LEGEND100-YEAR FLOOD PLAIN BASE FLOOD ELEVATION (BEF) = 27.6.UPSTREAM AREA TRIBUTARY TO STORM SEWER = 16.8± AC.ONSITE AREA TRIBUTARY TO STORM SEWER = 1.2± AC.REFERENCE(S)BACKGROUND LAYOUT PROVIDED BY TRIAD ASSOCIATES, ONJUNE 8TH, 2017, DELIVERED IN PDF FORMAT.
ATTACHMENT A GEOENGINEERS 1987 EXPLORATION LOGS
ATTACHMENT B GEOENGINEERS 2005 EXPLORATION LOGS