HomeMy WebLinkAboutGEO2021-00031 COM2021-00032 - COM Engineering / Geo-Tech Reports - 3/3/2021 �Eo 2021 - bo03I . Cohn 2-0 2- OW '.D,
GEORESOURCES
earth science & geotechnical engineering
4809 Pacific Hwy. E. I Fife, Washington 98424 1 253.896.1011 1 www. georesources.rocks
July 31, 2020
DM Belfair Investments, LLC RECEIVED
P.O. Box 217
Fox Island,Washington 98333
dmbelfair@outlook.com MAR 0 3 2021
Attn: Chris Reanier 615 W. Alder Street
Geotechnical Engineering Report
Proposed Commercial Development
23552 Northeast State Route 3
Maon County,PLANNING PN 5123294300 80&Washton
Doc ID: DMBelfairinvt.StateRt3.RG
INTRODUCTION
This geotechnical engineering report presents the results of our geotechnical assessment for
the proposed commercial development to be constructed at 23552 Northeast State Route 3 in
Mason County, Washington. The site consists of two Mason County tax parcels; one of which is
developed with two commercial buildings and the other is developed with a gravel parking area.
The general location is shown on the Site Location Map, Figure 1.
Our understanding of the project is based on our discussions with you, our review of the
Belfair Proposed Site Plan prepared by SFA Architects dated March 15, 2020, our understanding of the
Mason County development codes, our June 3, 2020 site visit and subsurface explorations, and our
experience in Mason County. The site is currently developed with two commercial office buildings,
paved driving aisles and parking stalls, and associated utilities. We understand that you propose to
construct a new commercial building in the southeast corner of the site, including additional paved
parking in the east central portion. Based on the preliminary site plan prepared by SFA Architects,
the proposed office building will be a two-story, wood-framed structure likely supported by
conventional shallow foundations. There is an existing septic drainfield, likely constructed during
the original site development, in the southeast corner and at the location of the proposed two-story
office building. The Belfair Proposed Site Plan prepared by SFA Architects is attached as the Site &
Exploration Plan, Figure 2.
Because of the height and inclination of slopes at and near the site, we anticipate that
Mason County will require an assessment be completed to address the Critical Area Ordinance per
Mason County Code 8.52.140. This Geotechnical Engineering Report addresses the stability of the
slopes near the site while providing geotechnical design recommendations. The completed Mason
County submittal checklist for a Geotechnical Report is attached to this report.
SCOPE
The purpose of our services was to evaluate the site conditions as a basis for assessing
potential adverse impacts to and from the slopes located within the site area and to provide
geotechnical design recommendations for the proposed development. Our site evaluation was
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performed in accordance with the Mason County Resource Ordinance regulations. Specifically, our
scope of services for this project included the following:
1. Reviewing the available geologic, hydrogeologic,and geotechnical data for the site area;
2. Exploring surface and subsurface conditions by reconnoitering the site and monitoring the
excavation of three test pit explorations across the site;
3. Describing surface and subsurface conditions, including soil type, depth to groundwater, and
an estimate of seasonal high groundwater levels;
4. Addressing the appropriate criteria for geologically hazardous areas per the current Mason
County Critical Area Ordinance Title 8.52.140, including recommended buffers and setbacks
as appropriate;
5. Providing recommendations for seismic design parameters, including 2015 IBC site class;
6. Evaluating the stability of the site using the computer program SLIDE 2018 by RocScience for
the proposed site conditions to meet MCC requirements;
7. Providing geotechnical conclusions and recommendations regarding site grading activities
including; site preparation, subgrade preparation, fill placement criteria, suitability of on-site
soils for use as structural fill,temporary and permanent cut and fill slopes, and drainage and
erosion control measures;
8. Providing geotechnical conclusions regarding foundations, including shallow foundation
parameters and floor slab support and design criteria, including bearing capacity and
subgrade modulus as appropriate;
9. Providing recommendations for subgrade walls, including lateral earth pressures and
applicable seismic surcharges;
10. Providing our opinion about the feasibility of on-site infiltration in accordance with the 2005
Stormwater Management Manual for Western Washington (SWMMWW), including a
preliminary design infiltration rate based on grain size data, as applicable;
11. Providing recommendations for erosion and sediment control during wet weather grading
and construction;
12. Preparing this Geotechnical Engineering Report summarizing our site observations and
conclusions, and our geotechnical recommendations and design criteria, along with the
supporting data; and,
13. Completing the Mason County submittal checklist for a Geotechnical Report.
The above scope of work was completed in accordance with our Proposal for Engineering
Services dated April 21, 2020. We received written authorization from Mr. Chris Reanier to proceed
on April 23, 2020.
SITE CONDITIONS
Surface Conditions
As referenced above, the site is located at 23552 Northeast State Route 3 in the City of
Belfair in Mason County, Washington, within an area of commercial development. The site consists
of two parcels that when combined is "L" shaped measuring about 120 to 360 feet wide (north to
south) by about 180 to 430 feet long (east to west) and encompass approximately 2.0 acres. The
two existing commercial buildings are situated in the southern portion of the site. The site is
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bounded by forestland/wetlands to the north and east, commercial development to the south, and
commercial development and State Route 3 to the west.
According to topographic information obtained from the Washington Department of Natural
Resources LiDAR portal and our field observations, the terrain across the site slopes up to the east
in a series of benches from State Route 3 to the eastern site boundary. From State Route 3, the
grade slopes gently up to the east at less than 10 percent for about 80 horizontal feet to an existing
commercial building (western). At the western building, the slopes steepen to about 20 to 40
percent for about 60 horizontal feet, with the building built into the slope with a daylight basement
configuration. The grade within the central portion of the site decrease to inclinations of less than 5
percent for about 90 horizontal feet up to the remaining commercial building (eastern) onsite. At
the eastern building, the grade again steepens to inclinations of 20 to 50 percent for about 50
horizontal feet. The eastern building is also built into the slope with a daylight basement
configuration. From the office building,the eastern portion is level to slightly sloping up towards the
east with inclinations of less than 5 percent for about 100 to 120 horizontal feet to the eastern site
boundary. At the eastern site boundary, the grade steepens to slopes of 15 to 40 percent. The
slopes continue to descend offsite to the southeast, forming a portion of the Union River Valley
sidewall. The current site topography is likely the result of grading associated with the original
commercial development of the site. The total vertical relief across the site is on the order of about
48 feet, and the topography of the site is shown on the Site Vicinity Map, Figure 3.
The slopes in the southeastern corner and continuing offsite to the southeast are generally
vegetated with various shrubs and ferns. Vegetation in the undeveloped portions generally consist
of ferns, horsetails, various grasses, and conifer trees. A septic drainfield is located within the
southeast corner of the site. The Union River flows north to south into the Hood Canal about 0.35
miles west of the site; with no other streams or upland water bodies within the general vicinity(less
than 300 feet). No evidence of significant surficial erosion, active soil movement, active landslide
activity or deep-seated slope instability was observed at the site or the adjacent areas at the time of
our site visit.
Site Soils
The USDA Natural Resource Conservation Service (NRCS) Web Soil Survey for Mason County
maps the site as being underlain by Everett very gravelly sandy loam (type Eh). The Everett very
gravelly sandy loam soils are derived from sandy and gravelly glacial outwash and are included in
hydrologic soils group A. Type Eh forms on slopes of 8 to 15 percent and is listed as having a "slight"
to "moderate" erosion hazard when exposed. A copy of the NRCS Web Soil Survey soil map for the
area of interest is included as Figure 4.
Site Geology
The Geologic Map of the Belfoir 7.5-minute Quadrangles Mason, Kitsap, and Pierce Counties,
Washington by Michael Polenz et al Quly 2009) maps the site as being underlain by alluvial fan
deposits (geologic unit Qaf). The alluvial fan deposits typically consist of a stratified and poorly
sorted mixture of silt, sand, gravel, and boulders. These deposits are the result of sediment load
deposited as streams emerge from confining valleys, reducing the load capacity of the stream as the
gradient flattens. These are Holocene and late Pleistocene non glacial deposits, from 14,000 years
ago to the present day, and are typically encountered in a loose and normally consolidated
condition. While variation is possible in the alluvial fan deposits, common USCS soil types
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encountered include GP, GW, SP, and SW. The composition of alluvial fan deposits typically allow for
infiltration of stormwater, but high groundwater levels are possible in alluvial fan deposits. An excerpt
from the referenced geologic map is included as Figure 5.
The Washington Department of Natural Resources Landslide Inventory and Compilations
indicate no landside deposits within 300 feet of the site. The nearest landslide deposit is mapped
approximately 1 mile to the north.
The site is not within the area mapped by the Washington Department of Ecology Coastal
Atlas Slope Stability. The slopes to the west and southwest (Sunset Beach) are mapped as a stable
(S)slope, so we would interpret the site to also be mapped as stable.
Subsurface Explorations
On June 3, 2020,we visited the site and monitored the excavation of three test pits to depths
of 10 to 11Y2 feet below the existing grade, logged the subsurface conditions encountered in each
test pit, and obtained representative soil samples. The test pits were excavated by a medium sized
track-mounted excavator operated by a licensed earthwork contractor working for GeoResources,
LLC. Table 1, below, summarizes the approximate functional locations, surface elevations, and
termination depths of our subsurface explorations.
TABLE 1:
APPROXIMATE LOCATIONS, ELEVATIONS,AND DEPTHS OF EXPLORATIONS
Test Pit Surface Termination Termination
Number Functional Location Elevation' Depth Elevation'
(feet) (feet) (feet)
TP-1 Northern parcel, proposed parking area 65 113/2 63Y2
TP-2 Northern parcel, proposed parking area 72 10 62
TP-3 Southern parcel, proposed building 74 11 63
Notes: ' Elevation based on interpolating between contours provided on the Belfair Proposed Site Plan prepared by SFA
Architects
The specific number, locations, and depths of our explorations were selected based on the
configuration of the proposed development, and were adjusted in the field based on consideration
for underground utilities, existing site conditions, site access limitations and encountered
stratigraphy. The soil densities presented on the logs are based on the difficulty of excavation and
our experience. Representative soil samples obtained from the test pits were placed in sealed
plastic bags and then taken to our laboratory for further examination and testing as deemed
necessary. The test pits were then backfilled with the excavated soils and bucket tamped, but not
otherwise compacted.
The subsurface explorations excavated as part of this evaluation indicate the subsurface
conditions at specific locations only, as actual subsurface conditions can vary across the site.
Furthermore, the nature and extent of such variation would not become evident until additional
explorations are performed or until construction activities have begun. Based on our experience in
the area and extent of prior explorations in the area, it is our opinion that the soils encountered in
the explorations are generally representative of the soils at the site.
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The soils encountered were visually classified in accordance with the Unified Soil
Classification System (USCS) and ASTM D2488. The USCS is included in Appendix A as Figure A-1.
The approximate locations and numbers of our test pits are shown on the Site & Exploration Plan,
included as Figure 2, while the descriptive logs of our test pits are included in Appendix A as Figure
A-2 and A-3.
Subsurface Conditions
At the locations explored, we encountered varied subsurface conditions that, in our opinion,
partially confirmed the mapped stratigraphy. During excavation of our test pits, we observed about '/a
to '/2 foot of brown silty topsoil mantling 4 to 63/a feet of brown, dark grey, and black poorly graded
sand to silty sand with variable amounts of gravel and cobbles in a loose to medium dense and moist
to wet condition. We interpret this soil layer as undocumented fill, likely cut from native soils during
the original commercial development of the site. We observed the undocumented fill to have
significant amounts of wood debris and other construction materials. Underlying the fill at test pit TP-
1 and TP-3, we encountered reddish brown, brown, and grey poorly graded sand and gravel with
variable amounts of silt and cobbles in a medium dense to dense and wet condition to the full depth
explored. We interpret this soil layer to be alluvial fan deposits. At test pit TP-2, we encountered grey
silty sand with gravel and cobbles in a dense to very dense and wet condition to the full depth
explored. We interpret this soil layer to be ice-contact deposits. The logs of our test pit explorations
are included in Appendix A. A summary of the conditions encountered at the locations explored is
provided in Table 2, below.
TABLE 2:
APPROXIMATE THICKNESSES, DEPTHS,AND ELEVATIONS OF SOIL LAYERS ENCOUNTERED IN
EXPLORATIONS
Topsoil Undocumented Depth to Alluvial Elevation' at Top of
Test Pit Thickness Fill Thickness Fan Deposits Alluvial Fan
Number Deposits
(feet) (feet) (feet) (feet)
TP-1 '/a 63/a 7 58
T P-2 Y2 5'/2 NE NE
TP-3 '/2 4 4'/2 69Y2
Notes: ' Elevation based on interpolating between contours provided on the Belfoir Proposed Site Pion prepared by SFA
Architects
NE=Not encountered
Laboratory Testing
Geotechnical laboratory tests were performed on two samples from our explorations to
determine index engineering properties of the soils encountered. Laboratory testing included visual
soil classification per ASTM D2488, moisture content determinations per ASTM D2216, grain size
analyses per ASTM D6913, and No. 200 washes per ASTM D1140 standard procedures. We
performed a moisture content determination and grain size analysis on a representative sample of
the alluvial fan and ice contact deposits. Test results are included in Appendix B.
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Groundwater Conditions
We observed groundwater seepage during excavation of test pit TP-1 and TP-3, at about 10
feet below existing grades. Iron oxide staining/discoloration consistent with soil mottling was
observed in the native alluvial fan and ice contact deposits at all exploration locations. Based on the
observed mottling and groundwater seepage, it is likely a relatively impermeable layer such as an
outwash silt bed, dense ice-contact deposits, or lodgement till is underlying the medium dense
alluvial fan deposits encountered at test pit TP-1 and TP-3. A wetland is also delineated in the
northern portion of the site.
Based on these observations and our review of the geologic literature of the area, the site is
likely prone to a shallow, "perched"groundwater table during and following periods of wet weather.
Perched groundwater develops when the vertical infiltration rate of precipitation through a more
permeable soil is slowed at depth by a deeper, less permeable soil type. We anticipate fluctuations
in the local groundwater levels that likely will occur in response to precipitation patterns, off-site
construction activities, and site utilization.
Below, Table 3 summarizes our depth and elevation of groundwater encountered in our
borings.
TABLE 3:
APPROXIMATE DEPTHS AND ELEVATIONS OF GROUNDWATER ENCOUNTERED IN EXPLORATIONS
Test Pit Depth to Elevation of
Date Observed
Number Groundwater(feet) Groundwater(feet)'
TP-1 10 55 ATD Oune 3, 2020)
TP-2 NE NE ATD(June 3, 2020)
TP-3 10 64 ATD (June 3, 2020)
Notes: ' Elevation based on interpolating between contours provided on the Belfair Proposed Site Plan prepared by SFA
Architects
ATD=At time of drilling
ENGINEERING CONCLUSIONS AND RECOMMENDATIONS
Based on our site observations and data review, it is our opinion that the proposed
commercial development is feasible from a geotechnical standpoint provided our recommendations
below are incorporated into the final plans and specifications. While the site has several of the listed
geologically hazardous area per MCCO 8.52.140 per MCCO 8.52.140, based on our site observations
and results of our slope stability analysis, the site appears to be "stable". This Geotechnical Report
should be sufficient and suitable to address the portions of the site where the commercial
development is proposed.
Geologically Hazardous Areas per Mason County Codes of Ordinance 8.52.140
According to the Mason County Resource Ordinance 8.52.140.E, the purpose of the landslide
hazard assessment is to identify areas that present potential dangers to public health and safety, to
prevent the acceleration of natural geological hazards, to address off site environmental impacts,
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and to minimize the risk to the property owner or adjacent property owners from development
activities.
Mason County uses the following indicators to determine if a site should be considered as a
Geologically Hazardous Area.
a. Areas with any indications of earth movement such as debris slides, earthflows, slumps
and rock falls.
b.Areas with artificial oversteepened or unengineered slopes, i.e. cuts or fills.
c. Areas with slopes containing soft or potentially liquefiable soils.
d. Areas oversteepened or otherwise unstable as a result of stream incision, stream bank
erosion, and undercutting by wave action.
e. Slopes greater than 15%(8.5 degrees)and having the following:
I. Hillsides intersecting geologic contacts with a relatively permeable
sediment overlying a relatively impermeable sediment or bedrock(e.g.
sand overlying clay);and
ii. Springs or groundwater seepage.
f. Any area with a slope of forty percent or steeper and with a vertical relief of ten or more
feet except areas composed of consolidated rock. A slope is delineated by establishing its
toe and top and measured by averaging the inclination over atleast ten feet of vertical
relief.
In addition, the following information may be used as a guide by the County to indicate
areas that have a higher likelihood of meeting the classification criteria above:
a.The areas identified on the Mason County Soil Survey Map as having slopes
greater than 15%.
b.The areas identified on the Coastal Zone Atlas,Volume 9, of Mason County,
Washington as:
I. Unstable- "U"
ii. Unstable Old Slides - "UOS"
iii. Unstable Recent Slides-"URS"
iv. Intermediate Slopes-"I"
v. Modified Slopes-"M"
c.The areas identified as Class 2, 3,4, or 5 of the maps: "Relative Slope Stability of the Southern
Hood Canal Area, Washington", by M. Smith and R.J. Carson, Washington State Department
of Natural Resources, Division of Earth Resources, 1977; and "The Geological Map of North
Central Mason County, Washington", by R.J. Carson, 1976, U.S. Geologic Survey OFR 76-2;
d.Areas mapped as landslide deposits(Map Unit Qls) on the: Geologic map of
the Longbronch 7.5-minute quadrangle, Thurston, Pierce, and Mason Counties, Washington, by
R. L. Logan, T.J. Walsh, and Michael Polenz. 1 sheet, scale 1:24,000, 2003; Geologic map of
the Squaxin Island 7.5-minute quadrangle, Mason and Thurston Counties, Washington, by R. L.
Logan, Michael Polenz, T. J. Walsh, and H. W. Schasse. 1 sheet, scale 1:24,000, 2003;
Geologic map of the Shelton 7.5-minute quadrangle, Mason and Thurston Counties,
Washington, by H. W. Schasse, R. L. Logan, Michael Polenz, and T.J. Walsh. 1 sheet, scale
1:24,000, 2003; and Geologic map of the Summit Lake 7.5-minute quadrangle, Thurston and
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Mason Counties, Washington, by R. L. Logan and T. J. Walsh. 42 x 36 in. color sheet, scale
1:24,000, 2004.
No indications of earth movement such as debris slides, earthflows, slumps and rock falls
were noted at the time of our site visit. No areas of over-steepened slopes as a result of wave
action, stream incision, or stream bank erosion were observed at the site. No soft or potentially
liquefiable soils are mapped at the site. The map "Relative Slope Stability of the Southern Hood Canal
Area, Washington" indicates that the eastern portion of the site is in an area identified as Class 3.
Class 3 is described as areas with slopes inferred to be unstable, but the same slopes north and
south of the site is listed as a Class 2. Class 2 areas are believed to be stable under normal
conditions. An excerpt of the"Relative Slope Stability of the Southern Hood Canal Area, Washington"for
the site and surrounding area is included as Figure 6.
Based on our test pit explorations and the available geologic and soil literature for the area,
the stratigraphy of the site is likely undocumented fill and coarse sediment alluvial fan deposits
mantling ice-contact deposits. The alluvial fan deposits are normally consolidated and typically fans
with coarser sediment are considered to have high permeability. We also encountered groundwater
seepage at about 10 feet below the ground surface, within the alluvial fan deposits, during our
subsurface explorations. A wetland is also mapped in the northern portion of the site.
Slopes greater than 15 percent are present in the southeast corner of the site, continuing
offsite towards the southeast. These slopes are mapped geologically as alluvial fan and advance
outwash deposits. Based on the observed geology of the site and available geologic literature for
the area we interpret the slopes may have intersecting geologic contacts with a relatively permeable
sediment (alluvial fan deposits) overlying a relatively impermeable sediment or bedrock (denser ice
contact deposits, glacial till deposits). Ice-contact deposits are known to have very dense till pods
and minor silt beds. The ice-contact deposits encountered at test pit TP-2 was in a dense to very
dense condition and appeared to be glacially consolidated. However, these steep slopes are well
vegetated, and no evidence of slope instability was observed at the site at the time of our site visit.
Based on our site observations and subsurface explorations, the mapped geology of the
area, and the steepness of the slopes in the southeast corner and offsite - we anticipate the
potential risk for deep-seated rotational landslides to be low. It is our opinion that while the steep
slopes in the southeastern portion of the site do meet the technical criteria of a geologically
hazardous area,the results of our slope stability analysis for existing conditions indicate that the site
is stable. In our opinion, no additional buffers should be required beyond the setbacks required by
the IBC building code, as discussed in the"Geologically Hazardous Areas"section of this report.
Seismic Hazard Areas per Mason County Resource Ordinance 8.S2.1SO
The purpose of the Seismic Hazard Section is to identify areas that present potential dangers
to public health and safety, and to prevent the acceleration of man-made and natural geological
hazards, and to neutralize the risk to the property owner or adjacent properties from development
activities.The following shall be classified as Seismic Hazard Areas:
1. Areas susceptible to ground failure including the following:
a. Areas with geologic faults;
b. Deep road fills and areas of poorly compacted artificial fill;
c. Areas with artificially steepened slopes(i.e. old gravel pits);
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d. Postglacial stream, lake or beach sediments;
e. River deltas;
f. Areas designated as potential Landslide Hazard Areas;
g. Bluff areas; and
h. Areas underlain by potentially liquefiable soils.
In addition,the following criteria may be used as a guide by the County to indicate areas that
have a higher likelihood of meeting the classification criteria above:
a. Areas identified on the Coastal Zone Atlas of Washington, Volume 9, Mason
County as Af, Qa1, Qa2, Qvc, Qls, Qos and Qp.
b. Areas identified on the Mason County Soil Survey Map as having slopes greater
than 15 percent.
c. Faults identified on "Map Showing Known or Suspected Faults With Quaternary
Displacement in the Pacific Northwest", A.M. Rogers, T.J. Walsh, W.J. Kockelman
and G.R. Priest, US Geologic Survey, 1996; or described in "Active Faulting
Investigations on the Canyon River Fault, Southern Olympic Range, Washington",
T.J.Walsh and K.G. Neal, U.S. Geologic Survey, 1997.
d. Areas underlain by potentially liquefiable soils as shown "Liquefaction
Susceptibility Map of Mason County, Washington" by Stephen P. Palmer,
Sammantha L. Magsino,James L. Poelstra, Eric L. Bilderback, Derek S. Folger, and
Rebecca A. Niggemann, September 2004.
Liquefaction is defined as a reduction or complete loss of soil strength due to an increase in
pore water pressure. The increase in pore water pressure is typically induced by seismic vibrations.
Liquefaction mainly affects geologically recent deposits of loose, fine-grained sands or coarse silts
that are below the groundwater table. The "Liquefaction Susceptibility Map of Mason County,
Washington" maps the site as a low risk for liquefaction. An excerpt of the map for the site area is
included as Figure 7. Based on the observed subsurface conditions and the site likely being prone to
seasonal perched groundwater, it is our opinion that the risk for liquefaction to occur at this site
during an earthquake is low to moderate. The site is underlain by Everett very gravelly sandy loam,
and no faults are identified on the "Map Showing Known or Suspected Faults with Quaternary
Displacement in the Pacific Northwest' within the site vicinity. Therefore, the site should not be
considered to be in a seismic hazard area.
Seismic Design
The site is located in the Puget Sound region of western Washington, which is seismically
active. Seismicity in this region is attributed primarily to the interaction between the Pacific,Juan de
Fuca and North American plates. The Juan de Fuca plate is subducting beneath the North American
plate at the Cascadia Subduction Zone (CSZ). This produces both intercrustal (between plates) and
intracrustal (within a plate) earthquakes. In the following sections we discuss the design criteria and
potential hazards associated with the regional seismicity.
—�_
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Seismic Site Class
Based on our observations and the subsurface units mapped at the site, we interpret the
structural site conditions to correspond to a seismic Site Class "D" in accordance with the 2015 IBC
documents and American Society of Civil Engineers (ASCE) standard 7-10 Chapter 20 Table 20.3-1.
This is based on the assumed range of SPT blow counts of the soils encountered. These conditions
are assumed to be representative for the subsurface across the site.
Design Parameters
The U.S. Geological Survey (USGS) completed probabilistic seismic hazard analyses (PSHA)
for the entire country in November 1996, which were updated and republished in 2002 and 2008.
We used the ATC Hazard by Location website to estimate seismic design parameters at the site.Table
4, below, summarizes the recommended design parameters.
TABLE 4:
2015 IBC PARAMETERS FOR DESIGN OF SEISMIC STRUCTURES
Spectral Response Acceleration (SRA)and Site Short
1 Second Period
Coefficients Period
Mapped SRA SS = 1.467 S, =0.584
Site Coefficients(Site Class D) Fa = 1.000 F,= 1.500
Maximum Considered Earthquake SRA Sans = 1.467 SM, = 0.876
Design SRA Sys=0.978 SD, =0.584
Peak Ground Acceleration
The mapped peak ground acceleration (PGA) for this site is 0.607g. To account for site class,
the PGA is multiplied by a site amplification factor(FPGA)of 1.0.The resulting site modified peak ground
acceleration (PGAM) is 0.52g. In general, estimating seismic earth pressures (kn) by the Mononobe-
Okabe method are taken as 50 percent of the PGAM, or 0.26g.
Slope Stability Analysis
We used the computer program SLIDE 2018 from RocScience to perform global slope
stability analyses under both static and seismic conditions for the existing and proposed conditions.
The computer program SLIDE 2018 uses a number of methods to estimate the factor of safety (FS)
of the stability of a slope by analyzing the shear and normal forces acting on a series of vertical
"slices" that comprise a failure surface. Each vertical slice is treated as a rigid body; therefore, the
forces and/or moments acting on each slice are assumed to satisfy static equilibrium (i.e., a limit
equilibrium analysis). The FS is defined as the ratio of the forces available to resist movement to the
forces of the driving mass. A FS of 1.0 means that the driving and resisting forces are equal; a FS
less than 1.0 indicates that the driving forces are greater than the resisting forces(indicating failure).
Table 5, below, summarizes the soil properties for various native soil types encountered in
the Puget Sound based on Geotechnical Properties of Geologic Materials by Koloski, Schwarz, and
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Tubbs as presented in Volume 1, ENGINEERING GEOLOGY IN WASHINGTON, Volume 1 (Washington
Division of Geology and Earth Resources Bulletin 78).
TABLE 5:
SOIL PROPERTIES FOR VARIOUS NATIVE SOIL TYPES ENCOUNTERED IN THE PUGET SOUND
Dry Unit Saturated Unit
Cohesion Phi
Unit Soil Type Weight Weight
(psf) (degrees)
(pcf) (pcfl
Colluvium Variable - Reflects Parent Material
Outwash SM, ML 115-130 N/A 0-1,000 30-40
Glacial Till GW, GP, SW, SP, SM 120-140 N/A 11000-4,000 35-45
Glacio-lacustrine ML, SM, SP 100-120 N/A 0-3,000 15-35
We analyzed the global and internal slope stability of the existing and proposed slope
geometry using subsurface profile A-A', as indicated on Figure 2. This original cross section was
selected as the most critical section given the height and steepness of the slopes relative to the
proximity of the proposed development. An inferred piezometric (groundwater) table was used
based on the seepage zone encountered during our site visit. The interpretation of the site geology
and geology of the slopes offsite towards the southeast is based on our subsurface explorations and
the Geologic Map of the Belfair 7.5-minute Quadrangles Mason, Kitsap, and Pierce Counties, Washington
by Michael Polenz at el (July 2009). The interpretation of the proposed development conditions is
TABLE 6:
ESTIMATED PROPERTIES OF ON-SITE GEOLOGIC UNITS FOR STABILITYANALYSIS
Dry Unit Saturated
Cohesion Phi
Geologic Unit Soil Type Weight Unit
( cf) Weight
{psi (degrees)
Structural Fill NA 125 N/A 0 36
Alluvial Fan Deposits GW, GP 115 120 0 34
Ice Contact Deposits SM, GM 130 N/A 350 36
Vashon Advance Outwash SP, SW 130 N/A 350 36
Pre-Vashon Undifferentiated NA 140 N/A 800 37
NE = Not encountered at time of digging
NA = Not available
based on the Belfair Proposed Site Plan prepared by SFA Architects. Table 6, below, summarizes our
assigned soil strength properties
We used the Bishop's Method of Circles, per the Mason County Code, to search for the
location of the most critical failure surfaces and their corresponding FS. The most critical surfaces
are those with the lowest FS for a given loading condition, and are therefore the most likely to move.
Our analyses included both static and dynamic loading conditions. For the seismic conditions, the
prescribed surcharge loading of 0.15g was applied in accordance with Section 8.52.140(E) of the
MCRO.
WNW-
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July 31, 2020
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The minimum F.S. for the existing conditions are 1.5 and 1.1 for static and seismic,
respectively. The minimum F.S. for the proposed development conditions are 1.9 and 1.3 for static
and seismic, respectively. This indicates that the proposed development will not adversely impact
the stability of the slope, instead improving the stability.
The proposed conditions include shallow foundations. Based on the global stability
analysis, the slope does not appear to be subject to deep-seated rotational or shallow failures from
the top of the slope or above the proposed two-story commercial building. The cross section and
slope stability results using both static and dynamic conditions are included in Appendix B.
Recommend Setback and Buffers
While no prescriptive buffers should be required, the Mason County building department will
require a setback from slopes steeper than 33 percent in accordance with the 2015 International
Building Code (IBC). The 2015 IBC section 1808.7 requires a building setback from slopes that are
steeper than 3H:1V(Horizontal:Vertical) unless evaluated and reduced and/or a structural setback is
provided by a licensed geotechnical engineer. The setback distance is calculated based on the
vertical height of the slope. The typical IBC setback from the top of the slope equals the lesser of
one third the height of the slope or 40 feet, while the typical IBC setback from the toe of the slope
equals the lesser of half the height of the slope or 15 feet.
Based on the topographic information obtained from the Mason County Public GIS website
and the Belfair Proposed Site Plan prepared by SFA Architects, existing slopes of greater than 33
percent are present within the proposed building footprint. We anticipate that grading for
construction of the building will eliminate the 33 percent or greater slopes in the southeastern
corner of the site. The slopes do continue offsite towards the southeast, but at inclinations of less
than 33 percent. Therefore, no setback from slopes steeper than 33 percent in accordance with the
2015 IBC should be required for the proposed building. If the development layout is altered, a
setback of 20 feet may be required from the southeast slopes if left in their current condition.
Where a setback cannot be met for the proposed building, the backwall should be a cast-in-place
concrete wall and have a height great enough such that the setback distance is measured from the
top of wall to the slope and its corresponding elevation.
Foundation Support
Based on the subsurface conditions encountered during our test pit explorations, it is our
opinion that the 2-story office building may be supported by a shallow foundation such as spread
footings. We recommend that the foundation footings by founded on the native alluvial fan
sediment deposits encountered at test pit TP-1 and TP-3, on the dense ice-contact deposits
encountered at test pit TP-2, or on properly prepared structural fill. The undocumented fill deposits
encountered across the site are not suitable to support the foundation, as the fill deposits were
observed to have significant organics and other debris such as glass and construction materials.
Spread Footings on Alluvial Fan Deposits or Bearing Pad
Spread footings founded on the medium dense alluvial fan deposits or on structural fill that
extends to suitable native soils may be designed with a maximum allowable bearing pressure of
1,500 psf (pounds per square foot) for combined dead and long-term live loads. If structural fill is
used as bearing pad material, it should be placed and compacted in accordance with the"Structural
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Fill"section of this report. The native soil at the base of the excavations should be disturbed as little
as possible.
All footing elements should be embedded at least 18 inches below grade for frost protection.
We recommend a minimum width of 2 feet for isolated footings and at least 16 inches for
continuous wall footings. The allowable bearing value may be increased by one-third for transient
loads such as those induced by seismic events or wind loads. The weight of the footing and any
overlying backfill may be neglected.
Lateral loads may be resisted by friction on the base of footings and floor slabs and as
passive pressure on the sides of footings. We recommend that an allowable coefficient of friction of
0.30 be used to calculate friction between the concrete and the underlying recessional soils. Passive
pressure may be determined using an allowable equivalent fluid density of 350 pcf (pounds per
cubic foot). Factors of safety have been applied to these values.
We estimate that total settlements of footings designed and constructed as recommended
above will be less than 1 inch over a 50-foot length, for the anticipated load conditions, with
differential settlements between comparably loaded footings of Y2 inch or less.
dread Footings on Ice Contact Deposits
Spread footings founded on the dense ice-contact deposits should be designed with a
maximum allowable bearing pressure of 2,500 psf for combined dead and long-term live loads. The
soils at the base of the footings should be disturbed as little as possible.
All footing elements should be embedded at least 18 inches below grade for frost protection.
We recommend a minimum width of 2 feet for isolated footings and at least 16 inches for
continuous wall footings. The allowable bearing value may be increased by one-third for transient
loads such as those induced by seismic events or wind loads. The weight of the footing and any
overlying backfill may be neglected.
Lateral loads may be resisted by friction on the base of footings and floor slabs and as
passive pressure on the sides of footings. We recommend that an allowable coefficient of friction of
0.35 be used to calculate friction between the concrete and the underlying ice contact soils. Passive
pressure may be determined using an allowable equivalent fluid density of 350 pcf (pounds per
cubic foot). Factors of safety have been applied to these values.
Floor Slab Support
The medium dense to dense alluvial and ice-contact soils or compacted structural fill would
provide a suitable subgrade for floor slabs constructed on grade. Where underlain by fill, we
recommend that the slabs be supported by a subgrade consisted of a minimum 12 inches of clean
structural fill. We recommend that a vertical modulus of subgrade reaction equal to 200 pounds per
cubic inch (pci) be used in the design of the floor slab-on-grade on medium stiff to stiff ice-contact
soils or on compacted, structural fill.
To provide firm bedding for floor slab, we recommend areas be prepared as described
above. The exposed soils should be compacted to at least 95 percent of the Modified Proctor(ASTM
D1557) maximum dry density and to a dense and unyielding condition. All fill under slab-on-grade
floors, including backfill for footing excavations, over-excavated areas, utilities, etc., should consist of
compacted structural fill.
Assuming below-grade building areas are constructed with long-term drainage, a capillary
break should be installed. We recommend that at-grade structures have a capillary break also. For
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capillary break, we recommend that a minimum 4 inch thick layer of washed pea gravel (3h-inch to
US No. 8 sieve size) or clean -%-inch crushed rock (less than 2 percent passing the US No. 200 sieve)
and a vapor retarder be placed beneath floor slabs. If pea gravel is used, a 2-inch layer of clean
crushed rock can be placed over a 4-inch minimum layer of washed pea gravel to provide a firmer
working surface on which to place the slab reinforcement.
A synthetic vapor retarder is strongly recommended to control moisture migration through
the slabs. This is of particular importance where the foundation elements are underlain by the silty
native soils, or where moisture migration through the slab is an issue, such as where adhesives are
used to anchor carpet or tile to the slab. It is likely the floor slab will be underlain by soils with a
high fines content.
Prior to placing pea gravel and/or crushed rock for a working surface or capillary break, the
exposed subgrade surface should be evaluated by a representative of our firm and compacted as
need to achieve a dense, unyielding condition.
Subgrade/Cast-in-Place Retaining Walls
The lateral pressures acting on retaining walls (such as basement or grade separation walls)
will depend upon the nature and density of the soil behind the wall as well as the presence or absence
of hydrostatic pressure. Below we provide recommended design values and drainage
recommendations for retaining walls.
Design Values
For walls backfilled with granular well-drained soil and a level backslope, the design active
pressure may be taken as 35 pcf(equivalent fluid density). For walls that are braced or otherwise
restrained, the design at-rest pressure may be taken as 55 pcf. For the condition of an inclined back
slope, higher lateral pressures would act on the walls. For a 3H:1V(Horizontal to Vertical)slope above
the wall, the active pressure may be taken as 48 pcf; for a 2H:1V back slope condition, a wall design
pressures of 55 pcf may be assumed If basement walls taller than 6 feet are required, as seismic
surcharge of 10H should be included where required by the code. If walls will be constructed with a
backslope and will be braced or otherwise restrained against movement,we should be notified so that
we can evaluate the anticipated conditions and recommend an appropriate at-rest earth pressure.
Lateral loads may be resisted by friction on the base of footings and as passive pressure on
the sides of footings and the buried portion of the wall, as described in the "Foundation Support"
section of this report.
Wall Drain=
Adequate drainage behind retaining structures is imperative. Positive drainage which
controls the development of hydrostatic pressure can be accomplished by placing a zone of
drainage behind the walls. Granular drainage material should contain less than 2 percent fines and
at least 30 percent retained on the US No. 4 sieve.
A minimum 4-inch diameter perforated or slotted PVC pipe should be placed in the drainage
zone along the base and behind the wall to provide an outlet for accumulated water and direct
accumulated water to an appropriate discharge location. We recommend that a nonwoven
geotextile filter fabric be placed between the soil drainage material and the remaining wall backfill to
reduce silt migration into the drainage zone. The infiltration of silt into the drainage zone can, with
time, reduce the permeability of the granular material. The filter fabric should be placed such that it
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July 31,2020
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fully separates the drainage material and the backfill, and should be extended over the top of the
drainage zone.Typical wall drainage and backfilling details are shown on Figure 9.
A geocomposite drain mat may also be used instead of free draining soils, provided it is
installed in accordance with the manufacturer's instructions. A soil drainage zone should extend
horizontally at least 18 inches from the back of the wall. The drainage zone should also extend from
the base of the wall to within 1 foot of the top of the wall. The soil drainage zone should be
compacted to approximately 90 percent of the maximum dry density (MDD), as determined in
accordance with ASTM D1557. Over-compaction should be avoided as this can lead to excessive
lateral pressures on the wall.
Site Drainage
All ground surfaces, pavements and sidewalks at the site should be sloped away from the
structures. The site should be graded to ensure positive drainage away from all structures, property
lines, and the steep slopes on and adjacent to the southeast corner of the site. Surface water runoff
from the roof areas, driveways, perimeter footing drains, and wall drains should be collected,
tightlined, and conveyed to an appropriate discharge point. We recommend that footing drains are
installed for the proposed structures in accordance with IBC 1805.4.2.
Stormwater Infiltration Recommendations
Mason County has adopted the 2005 Stormwater Management Manual for Western
Washington (2005 SWMMWW). Based on the results of our site reconnaissance, observations,
subsurface explorations, and laboratory test results, it is our opinion that onsite infiltration of the
stormwater runoff is not feasible for the proposed development because of the undocumented fill
and shallow groundwater.
As described in our"Subsurface Explorations" portion of this report, the soils encountered
across the site were consistent with undocumented fill mantling alluvial fan and ice-contact
deposits. While it is our opinion that the observed alluvial fan deposits at test pit TP-1 and TP-3 are
consistent with Type "A" soils, we also encountered groundwater seepage at 10 feet below existing
grade. Iron-oxide staining/discoloration consistent with soil mottling was also observed throughout
the native alluvial fan and ice-contact deposits. It is our opinion that the site is prone to a shallow
seasonal perched groundwater table, and the separation requirement for infiltration facilities likely
cannot be met during periods of prolonged wet weather. Areas where there is no fill and facilities
could be sized to maintain 3 feet of separation,the alluvial soils could provide an infiltration rate of 2
inches per hour. However, we recommend all runoff be collected and dispersed into the adjacent
buffer.
Erosion Control
No evidence of surficial raveling or sloughing was observed at the site at the time of our
visits. To manage and reduce the potential erosion at the site, we recommend erosion protection
measures will need to be in place prior to construction activity on the site. Erosion hazards can be
mitigated by applying Best Management Practices(BMPs)outlined in the 2005 SWMMWW.
Weathering, erosion and the resulting surficial sloughing and shallow land sliding are natural
processes that affect slope areas. To manage and reduce the potential for these natural processes,
we recommend the following:
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• No drainage of concentrated surface water or significant sheet flow onto or near the
slope area.
• Grading should be limited to providing surface grades that promote surface flows
away from the top of slope to an appropriate discharge location beyond the toe of the
slope.
Erosion protection measures should be in place prior to the start of construction activity on
the site and should be maintained throughout construction and until final site stabilization is
established. Where native vegetation is removed, a dense vegetative groundcover, grass lawn, or
native vegetation should be reestablished as soon as feasible. Erosion control Best Management
Practices (BMPs) contained in the adopted 2005 Stormwater Management Manual for Western
Washington, such as jute matting or straw wattles, should be installed and maintained until
vegetation has been reestablished.
Vegetation Management
Removal of trees and vegetation can adversely affect the overall slope stability, however, if
done properly,vegetation management can result in a healthy, well vegetated slope. We recommend
an arborist be consulted for tree trimming and/or removal activities. If it is necessary to cut or
remove trees,the stumps should be left in place to limit the potential for exposed soils and erosion.
Where the vegetation or soil is disturbed during grading and construction activities, it should
be restored or mitigated with other erosion control measures until the vegetation is reestablished. It
may be necessary to reseed areas where the vegetation is completely removed or severely damaged.
We recommend obtaining a copy of the WA DOE "Vegetation Management: a Guide for Puget
Sound Bluff Property Owners" (93-31) or"Slope Stabilization and Erosion Control Using Vegetation" (DOE
Publication 93-30), available online,for selecting appropriate types of deep-rooting native vegetation
to be used in the permanent revegetation and stabilization of the slope area.
EARTHWORK RECOMMENDATIONS
Site Preparation
All areas of the site to be repaired should be stripped of organic surface soils and other
deleterious materials. We anticipate stripping depths for the development to be on the order of
about Y2 a foot. The undocumented fill encountered during our subsurface explorations was
observed having a significant amount of organics and manmade debris. We recommend that this fill
be removed and anticipate that about 43h to 7 feet of over-excavation will be required to remove the
undocumented fill soils. Where placement of fill material is required, the stripped and exposed
subgrade areas should be compacted to a firm and unyielding surface prior to placement of any fill.
Excavations for debris removal should be backfilled with structural fill compacted to the densities
described in the "Structural Fill" section of this report. Any utility lines that are being replaced or
abandoned should be removed, and/or plugged or capped, as appropriate.
We recommend that a member of our staff evaluate the exposed subgrade conditions after
stripping is completed and prior to placement of structural fill and or base coarse material for the
parking areas. The exposed subgrade soil should be probed with a Yz-inch-diameter steel T-probe.
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DM Belfai rinvt.StateRt3.RG
July 31, 2020
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Any soft, loose, or otherwise unsuitable areas delineated during probing should be
recompacted, if practical, or over-excavated and replaced with structural fill. The depth and extent
of overexcavation should be evaluated by our field representative at the time of construction.
Structural Fill
All material placed as fill associated with mass grading or under building areas should be
placed as structural fill. The structural fill should be placed in horizontal lifts of appropriate
thickness to allow adequate and uniform compaction of each lift. Fill should be compacted to at
least 95 percent of the MDD.
The appropriate lift thickness will depend on the fill characteristics and the compaction
equipment used. We recommend that the appropriate lift thickness be evaluated by our field
representative during construction, and that our representative be present during site grading
activities to observe the work and perform field density tests, as appropriate.
The suitability of material for use as structural fill will depend on the gradation and moisture
content of the soil. As the percent of fines (material passing US No. 200 sieve) increases, soil
becomes increasingly sensitive to small changes in moisture content and adequate compaction
becomes more difficult to achieve. During wet weather, we recommend use of well-graded sand
and gravel with less than 5 percent (by weight) passing the US No. 200 sieve based on that fraction
passing the 3/4-inch sieve, such as"Gravel Backfill for Walls"(9-03.12(2))or"Bank Run Gravel for Trench
8ackfill" (9-03.19). If prolonged dry weather prevails during the earthwork and foundation
installation phase of construction, higher fines content(up to 10 to 12 percent) may be acceptable.
Material placed for structural fill should be free of debris, organic matter, trash, and cobbles
greater than 6-inches in diameter. The moisture content of the fill material should be adjusted as
necessary for proper compaction.
Suitability of On-Site Materials as Fill
The upper approximately 4 to 7 feet of soils encountered at the location of the proposed
development are consistent with undocumented fill soils. The fill soils encountered onsite may be
suitable for use as structural fill material if all organics and manmade debris is removed prior to
usage. This may prove to be difficult, as portions of the fill was observed to have a significant
amount of organics. The undocumented fill likely has a low to moderate amount (about 5 to 20
percent) of fines. The native ice-contact and alluvial fan deposits encountered underlying the
undocumented fill will be suitable for usage as fill, where needed. As the percentage of fines
increases, soil becomes increasingly more sensitive to small changes in moisture content and
adequate compaction becomes more difficult or impossible to achieve. The soils were generally
moist to wet at the time of our explorations. If earthwork occurs during a typical wet season, or if
the soils are persistently wet and cannot be dried due to wet weather conditions, we recommend
the use of imported structural fill,as described above.
We recommend that completed graded-areas be restricted from traffic or protected prior to
wet weather conditions. The graded areas may be protected by paving, placing asphalt-treated
base, a layer of free-draining material such as pit run sand and gravel or clean crushed rock material
containing less than 5 percent fines, or some combination of the above.
Temporary Excavations
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All job site safety issues and precautions are the responsibility of the contractor providing
services/work. The following cut/fill slope guidelines are provided for planning purposes only.
Temporary cut slopes will likely be necessary during grading operations or utility installation. All
excavations at the site associated with confined spaces, such as utility trenches and retaining walls,
must be completed in accordance with local, state, or federal requirements.
Based on current Washington Industrial Safety and Health Act (WISHA, WAC 296-155-66401)
regulations, it is our opinion that the ice contact soils on the site would be classified as Type B soils
and the alluvial fan deposits would be classified as Type C soils.
According to WAC 296-155-66403, for temporary excavations of less than 20 feet in depth,
the side slopes in Type B soils should be laid back at a slope inclination of 1 H:1V(Horizontal:Vertical)
or flatter from the toe to the crest of the slope. The side slopes in Type C soils should be laid back at
a slope inclination of 11hH:1V. All exposed slope faces should be covered with a durable reinforced
plastic membrane during construction to prevent slope raveling and rutting during periods of
precipitation. These guidelines assume that all surface loads are kept at a minimum distance of at
least one half the depth of the cut away from the top of the slope and that significant seepage is not
present on the slope face. Flatter cut slopes will be necessary where significant raveling or seepage
occurs, or if construction materials will be stockpiled along the slope crest.
Where it is not feasible to slope the site soils back at these inclinations, a retaining structure
should be considered. Where retaining structures are greater than 4 feet in height (bottom of
footing to top of structure) or have slopes of greater than 15 percent above them, they should be
engineered per Washington Administrative Code (WAC 51-16-080 item 5). This information is
provided solely for the benefit of the owner and other design consultants, and should not be
construed to imply that GeoResources assumes responsibility for job site safety. It is understood
that job site safety is the sole responsibility of the project contractor.
Construction Observation
We recommend that GeoResources, LLC be retained to observe the geotechnical aspects of
construction including foundations. This observation would allow us to verify the subsurface
conditions as they are exposed during construction and to determine that work is accomplished in
accordance with our recommendations. If conditions encountered during construction differ from
those anticipated,we can provide recommendations and mitigation for the conditions encountered.
LIMITATIONS
We have prepared this revised report for use by DM Belfair Investments, LLC and members of
the design team to address code compliance requirements imposed by Mason County. The data used
in preparing this report and this report should be provided to prospective contractors for their bidding
or estimating purposes only. Our report, conclusions and interpretations are based on data from
others and limited site reconnaissance, and should not be construed as a warranty of the subsurface
conditions.
Variations in subsurface conditions are possible between the explorations and may also occur
with time. A contingency for unanticipated conditions should be included in the budget and schedule.
Sufficient monitoring, testing and consultation should be provided by our firm during construction to
confirm that the conditions encountered are consistent with those indicated by the explorations, to
provide recommendations for design changes should the conditions revealed during the work differ
GEORESOURCES
D M Be lfa i rl nvt.State Rt3.RG
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page 1 19
from those anticipated, and to evaluate whether earthwork and foundation installation activities
comply with contract plans and specifications. The scope of our services does not include services
related to environmental remediation and construction safety precautions. Our recommendations are
not intended to direct the contractor's methods, techniques, sequences or procedures, except as
specifically described in our report for consideration in design.
Within the limitations of scope, schedule and budget, our services have been executed in
accordance with generally accepted practices in this area at the time this report was prepared. No
other conditions, express or implied,should be understood.
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D M Be I fa i rl nvt.StateRt3.RG
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We appreciate the opportunity to be of service to you on this project. If you have any
questions or require additional services, please contact us.
Respectfully submitted,
GeoResources, LLC
Erik Fina, GIT
Staff Geologist
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KEITH SCOT' SCFIEMBg ERIC WILIA
Keith S. Schembs, LEG Eric W. Heller, PE, LG
Principal Senior Geotechnical Engineer
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DocID:DMBelfairinvt.StateRt3.RG
Attachments: Figure 1:Site Location Map
Figure 2:Site&Exploration Plan
Figure 3:Site Vicinity Map
Figure 4:NRCS Soils Map
Figure 5:Geologic Map
Figure 6:Relative Slope Stability of the Southern Hood Canal Area Map
Figure 7:Liquefaction Susceptibility of Mason County
Figure 8:Typical Wall Drainage&Backfilling Detail
Appendix A:Subsurface Explorations
Appendix B:Laboratory Test Results
Appendix C:Slope Stability Results
GEORESOURCES
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,sources:Esri, HERE,Garmin,USGS, Intermap, INCREMENT P,NRCan,Esri
/Japan, METI, Esri China(Hong Kong),Esri Korea.Esri(Thailand),NGCC,(c)
(OpenStreetMap contributors,and the GIS User Community
Approximate Site Location
Figure created from World Street Map
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Not to Scale
Site Location Map
Proposed Commercial Development
23552 Northeast State Route 3
GE 0 R E S 0 U R C E S Mason County, Washington
earth science & geotechnical engineering PN: 123294300180 & 123294390173
4809 Pacific Hwy.E. I We,WA 98424 1 253.896.1011 1 www.georesources.rocks
DocID:DM Belfairinvt.StateRt3.F July 2020 Figure 1
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Approximate Site & Exploration Plan
Proposed Commercial Development
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Mason County,Washington
0 s0 12o PN: 123294300180& 123294390173
Ifairinvt.5tateRt3.P July 2020 Figure=2
Approximate Site Location
Figure created from basemap (clarity)at ArcGIS Online and contour and parcel shapefile downloaded from Mason County
GIS
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Site Vicinity Map
Proposed Commercial Development
23552 Northeast State Route 3
G E 0 R E S 0 U R C E S Mason County,Washington
earth science & geotechnical engineering PN: 123294300180 & 123294390173
4809 Pacific Hwy.E. I Fite,WA 98424 1 253.896.1011 1 www.georesources.rocks
DocID:DMBelfairinvt.StateRt3.F July 2020 Figure 3
Approximate Site Location
Figure created from shapefile AOI downloaded from Web Soil Survey
(http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx)
Soil Soil Name Parent Material Slopes(%) Erosion Hydrologic
Type Hazard Soils Group
Everett very Slight to
Eh gravelly sandy Sandy and gravelly glacial outwash 8 to 15 Moderate A
loam
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NRCS Soils Map
Proposed Commercial Development
23552 Northeast State Route 3
GE 0 R E S 0 U R C E S Mason County, Washington
earth science & geotechnical engineering PN: 123294300180 & 123294390173
4809 Pacific Hwy.E. I Fife.WA 98424 1 253.896.1011 1 www.georesources.rocks
DocID:DMBelfairinvt.5tateRt3.F July 2020 Figure 4
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Approximate Site Location
An excerpt from the Geologic Map of the Belfair 7.5-minute Quadrangle Mason, Kitsap, and Pierce Counties, Washington
by Michael Polenz, Katelin Alldritt, Nicholas J. Hehemann, Isabelle Y. Sarikhan, and Robert L. Logan Quly 2009)
Qaf ,. Alluvial fan
Qgof Vashon recessional outwash fines
Qga Vashon advance outwash
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Geologic Map
Proposed Commercial Development
23552 Northeast State Route 3
GE 0 R E S 0 U R C E S Mason County,Washington
earth science & geotechnical engineering PN: 123294300180 & 123294390173
4809 Pacific Hwy.E. I Fife,WA 98424 1 253.896.1011 1 www.georesources.rocks
DocID:DM Belfairinvt.5tateRt3.F July 2020 Figure 5
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Approximate Site Location
Map created from Relative Slope Stability of the Southern Hood Canal Area, Washington by Mackey Smith and R j. Carson WA
Department of Natural Resources
Class 2: Areas believed to be stable under normal conditions
Class 3: Areas inferred to be unstable
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Relative Slope Stability of the Southern Hood
Canal Area Map
Proposed Commercial Development
G E O R E S O U R C E S 23552 Northeast State Route 3
Mason County, Washington
earth science & geotechnical engineering PN: 123294300180 & 123294390173
4809 Pacific Hwy.E. 1 Fife,WA 98424 1 253.896.1011 1 www.georesources.rocks --T
DocID:DMBelfairinvt.StateRtIF July 2020 Figure 6
Form aft*
Approximate Site location
Map created from Liquefaction Susceptibility Map of Mason County, Washington
By Stephen P. Palmer, Sammantha L. Magsino, Eric L. Bilderback,James L. Poelstra, Derek S. Folger, and Rebecca A.
Niggemann
Liquefaction susceptibility:VERY LOW
Liquefaction susceptibility: LOW
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Liquefaction Susceptibility of Mason
,.. County
Proposed Commercial Development
23552 Northeast State Route 3
G E O R E S O U R C E S
earth science & geotechnical engineering Mason County, Washington
4809 Pacific Hwy.E. I Fife,WA 99424 1 2S3.896.1011 I www.georesources.rocks PN: 123294300180 & 123294390173
DocID:DMBelfairinvt.stateRt3.F July 2020 Figure 7
SLOPED TO DRAIN ELOW GRADE WALL
AWAY FROM STRUCTURE RAINAGE SAND AND GRAVEL
(SEE NOTE 3)
DAMP PROOFING
PAVEMENT OR 18H
IMPERVIOUS SOIL
���. EEP HOLES (SEE NOTE 1)
WALL BACKFILL
SEE NOTE
ma's LOOR SLAB
EXCAVATION SLOPE ="l VAPOR RETARDER
;..
CONTRACTOR'S REPSONSIBILITY _Z
Z
6" MIN ON SIDES OF PIPE; Z
2' BELOW Z io
x � 00
CQ T
C
WASHED PEA GRAVEL/CLEAN
N CRUSHED GRAVEL
ERIMETER/SUBDRAIN PIPE
1. Washed pea gravel/crushed rock beneath floor slab could be 6. The subdrain should consist of 4"diameter(minimum),
hydraulically connected to perimeter/subdrain pipe.Use of 1" slotted or perforated plastic pipe meeting the requirements
diameter weep holes as shown is one applicable method.Crushed of AASHTO M 304;1/8-inch maximum slot width;3/16-to 3/8-
gravel should consist of 3/4"minus.Washed pea gravel should consist inch perforated pipe holes in the lower half of pipe,with
of 3/8"to No.8 standard sieve. lower third segment unperforated for water flow;tight joints;
sloped at a minimum of 6"/100'to drain;cleanouts to be
2. Wall backfill should meet WSDOT Gravel Backfill for Walls Specification provided at regular intervals.
9-03-12(2).
7. Surround subdrain pipe with 8 inches(minimum)of washed
3. Drainage sand and gravel backfill within 18"of wall should be pea gravel(Z'below pipe"or 5/8"minus clean crushed gravel.
compacted with hand-operated equipment.Heavy equipment should Washed pea gravel to be graded from 3/8-inch to No.8
not be used for backfill,as such equipment operated near the wall standard sieve.
could increase lateral earth pressures and possibly damage the wall.
The table below presents the drainage sand and gravel gradation. 8. See text for floor slab subgrade preparation.
4. All wall back fill should be placed in layers not exceeding 4"loose
thickness for light equipment and 8"for heavy equipment and should
be densely compacted.Beneath paved or sidewalk areas,compact to Materials
at least 95%Modified Proctor maximum density(ASTM:01557-70 Drainage Sand and Gravel 3W Minus Crushed Gravel
Method Q.In landscaping areas,compact to 90%minimum. Sieve Size %Passing by Sieve Size %Passing by
Weight Weight
5. Drainage sand and gravel may be replaced with a geocomposite core 3/4" 100 100
sheet drain placed against the wall and connected to the subdrain No 4 28-56 V 75—100
pipe.The geocomposite core sheet should have a minimum No 8 20-50 �/:' 0-25
transmissivity of 3.0 gallons/minute/foot when tested under a gradient No 50 3-12 No 100 0-2
of 1.0 according to ASTM 04716. No 100 1 0-2 (b wet sievin ) I (non-plastic)
Typical Wall Drainage & Backfill Detail
Proposed Commercial Development
23552 Northeast State Route 3
GE 0 R E S 0 U R C E S Mason County,Washington
earth science & geotechnical engineering PN: 123294300180 & 123294390173
4809 Pacific Hwy.E. I Fife,WA 99424 I 2S3.896.1011 I www.georesources.rocks
DocID:DMBelfairinvt.5tateRt3.F July 2020 Figure 7
Appendix A
Subsurface Explorations
SOIL CLASSIFICATION SYSTEM
MAJOR DIVISIONS GROUP GROUP NAME
SYMBOL
GRAVEL CLEAN GW WELL-GRADED GRAVEL,FINE TO COARSE GRAVEL
GRAVEL
GP POORLY-GRADED GRAVEL
COARSE
GRAINED More than 50% GRAVEL GM SILTY GRAVEL
SOILS Of Coarse Fraction WITH FINES
Retained on GC CLAYEY GRAVEL
No.4 Sieve
SAND CLEAN SAND SW WELL-GRADED SAND,FINE TO COARSE SAND
More than 50% SP POORLY-GRADED SAND
Retained on
No.200 Sieve More than 50% SAND SM SILTY SAND
Of Coarse Fraction WITH FINES
Passes SC CLAYEY SAND
No.4 Sieve
SILT AND CLAY INORGANIC ML SILT
FINE CL CLAY
GRAINED
SOILS Liquid Limit ORGANIC OL ORGANIC SILT,ORGANIC CLAY
Less than 50
SILT AND CLAY INORGANIC MH SILT OF HIGH PLASTICITY,ELASTIC SILT
More than 50% CH CLAY OF HIGH PLASTICITY,FAT CLAY
Passes
No.200 Sieve Liquid Limit ORGANIC OH ORGANIC CLAY,ORGANIC SILT
50 or more
HIGHLY ORGANIC SOILS PT PEAT
NOTES: SOIL MOISTURE MODIFIERS:
1. Field classification is based on visual examination of soil Dry- Absence of moisture,dry to the touch
in general accordance with ASTM D2488-90.
Moist- Damp,but no visible water
2. Soil classification using laboratory tests is based on
ASTM D6913. Wet- Visible free water or saturated,usually soil is
obtained from below water table
3. Description of soil density or consistency are based on
interpretation of blow count data,visual appearance of
soils,and or test data.
Unified Soils Classification System
Proposed Commercial Development
23552 Northeast State Route 3
GE 0 R E S 0 U R C E S Mason County, Washington
earth science & geotechnical engineering PN: 123294300180 & 123294390173
4809 Pacific Hwy.E. I Fife.WA 98424 1 253.896.1011 1 www.seoresources.rocks
DocID:DMBelfairinvt.StateRt3.F July 2020 Figure A-1
Test Pit TP-1
Location:Northern parcel,proposed parking lot
Approximate Elevation:65 feet
Depth(ft) Soil Type Soil Description
0 - 1/4 - Dark brown topsoil
Y - 7 SP-SM Dark grey poorly graded SAND with silt,gravels,and cobbles, relict topsoil,glass,wood
debris(loose to medium dense, moist to wet)(Undocumented Fill)
7 - 11 GW-GM Brown well graded GRAVEL with silt,sand,and cobbles(medium dense to dense,wet)
(Alluvial Fan Deposits)
Terminated at 11 feet below ground surface(bgs).
Iron oxide staining/mottling observed from 7 to 11 feet bgs at the time of excavation.
Groundwater seepage observed at 10 feet bgs the time of excavation.
Moderate caving observed from 1/4 to 7 feet bgs at time of excavation.
Test Pit TP-2
Location: Northern parcel, proposed parking lot
Approximate Elevation:72 feet
_ Depth(ft) Soil Type Soil Description
0 Y2 - Brown topsoil
Y2 - 6 SM Brown to black silty SAND with gravel and cobbles,wood debris,wet at 6Y2 feet(medium
dense, moist to wet)(Undocumented Fill)
6 - 10 SM Grey silty SAND with gravel and cobbles(dense to very dense,wet)(Ice-Contact Deposits)
Terminated at 10 feet below ground surface(bgs).
Iron oxide staining/mottling observed from 6 to 10 feet bgs at the time of excavation.
No groundwater seepage observed at the time of excavation.
No caving observed at time of excavation.
Logged by: EJF Excavated on:June 3,2020
Test Pit Logs
Proposed Commercial Development
23552 Northeast State Route 3
GE 0 R E S 0 U R C E S Mason County,Washington
earth science & geotechnical engineering PN: 123294300180 & 123294390173
4809 Pacific Hwy.E. I Fife,WA 99424 1 253.896,1011 1 www.georesources.rocks
DocID:DM13elfairinvt.StateRt3.F July 2020 Figure A-2
Test Pit TP-3
Location:Southern parcel,proposed two story commercial building
Approximate Elevation:75 feet
Depth(ft) Soil Type Soil Description
0 - 1h - Brown topsoil
Y2 - 4Y2 sM Black to grey silty SAND with gravel, roots(loose to medium dense, moist)(Undocumented Fill)
4Y2 - 6 SP Reddish brown poorly graded SAND with silt and gravel(medium dense)(Weathered Alluvial Fan
Deposits)
6 11 GP-GM Grey poorly graded GRAVEL with silt,sand,and cobbles,wet and dense at 8 feet(medium dense
to dense)(Alluvial Fan Deposits)
Terminated at 11 feet below ground surface(bgs).
Iron oxide staining/mottling observed from 4Y2 to 11 feet bgs at the time of excavation.
Groundwater seepage observed at 10 feet bgs the time of excavation.
No caving observed at time of excavation.
Logged by: EJF Excavated on:June 3, 2020
Test Pit Logs
Proposed Commercial Development
23552 Northeast State Route 3
GE 0 R E S 0 U R C E S Mason County,Washington
earth science & geotechnical engineering PN: 123294300180 & 123294390173
4809 Pacific Hwy.E. I Fife.WA 99424 1 253.896.1011 1 www.georesources.rocks
DocID:DMBelfair1nvt.5tateRt3.F July 2020 Figure A-3
Appendix B
Laboratory Test Results
Particle Size Distribution Report
100
ID
so
80
7o
w
Z 60
Z 50
w
W 40
w
d
30
20
10 i i i
I ill
Ill
0 i T
i i i i i i
100 10 1 0.1 0.01 0.001
v; GRAIN SIZE-mm.
T N %Gravel %Sand %Fines
E +3 Coarse Fine coarse Medium Fine Silt clay
~ 0.0 1 22.0 18.6 5.4 11.7 28.4 13.9
Test Results(ASTM D 6913& ASTM C 117� ) Material Description
o -a Opening Percent Spec! Pass? silty sand with gravel
m - Size Finer (Percent) (X=Fail)
(D aa) 3.0 100.0
m 2.5 100.0 Atterberg Limits(ASTM D 4318)
L 2.0 100.0 PL= NP LL= NV PI= NP
m
0 0 '.2 '92_0
15 Classification
3 > 1 87.9 USCS(D 2487)= SM AASHTO(M 145)= A-1-b
o .2 75 78.0 Coefficients
v .5 69.3 D90= 29.3889 D85= 22.9657 D60= 5.1149
�°- 0.375 65.8 D50= 0.9286 D30= 0.2640 D15= 0.0899
°c #4 59.4 1310= Cu= Cc=
m ° #10 54.0 Remarks
w co #20 49.5
° v #40 42.3
of CO #60 28.6
v
#100 19.5
$? #200 13.9 Date Received: 06/03/2020 Date Tested: 07/09/2020
.N m
Tested By: ELL
aXi -
m E Checked By:
'n Title:
o m
N w (no specification provided)
f° Location:Test Pit TP-2/Sam le-1
:099942 Del2thp • 7.5 feet
Date Sampled: 06/03/2020
•. c
h °
GeoResources, LLC Client: DM Belfair Investments,LLC
_
(DProject: Proposed Commercial Development
m
cc
Fife WA ProleN Ml3 if 'rInvt Fi ur
Tested By: Checked By:
Particle Size Distribution Report
100
90
so
7o
Z 60
Z 50
LLI
40
LLI
0_
30
20
10
0
100 10 1 0.1 0.01 0.001
v; GRAIN SIZE-mm.
%+3„ %Gravel %Sand %Fines
E Coarse Fine Coarse Medium Fine Silt Clay
f- y
0.0 23.8 28.5 10.0 14.3 16.4 7.0
Test Results(ASTM D 6913& ASTM C 117) Material Description
o-Do Opening Percent Spec.* Pass? poorly graded gravel with silt and sand
0) - Size Finer (Percent) (X=Fail)
3 3.0 100.0
> m 2.5 100.0 Atterberg Limits(ASTM D 43181
t 2.0 100.0 PL= NP LL= NV PI= NP
1.5 100.0
Classification
t�a)) 1.25 93.6
a USCS(D 2487)= GP-GM AASHTO(M 145)= A-]-a
3 > 1 85.4
o .- .75 76.2 Coefficients
.5 64.8 D90= 28.9630 D85= 25.1303 D60= 9.4920
0.375 60.1 D50= 5.4430 D30= 0.7822 D15= 0.2554
#4 47.7 D10= 0.1551 Cu= 61.21 Cc= 0.42
a� #10 37.7
cc w #20 30.7 Remarks
w
0 -0 #40 23.4
U) m #60 14.7
o #100 9.8
#200 7.0 Date Received: 06/03/2020 Date Tested: 07/09/2020
.N m
u, Tested By: OF
x
0) E Checked By:
w Title:
0 a)
w (no specification provided)
f6 ° Location: Test Pit TP-3/Sample-1 Date Sampled: 06/03/2020
c
Sample Nu
ber: 099943 :6.0 feet
w 0 Client: DM Belfair Investments,LLC
_ GeoResources, LLC
(DProject: Proposed Commercial Development
M
Fife WA Pr ' Ng: DMJ3glfWrI FiaMre B-
Tested By: Checked By:
Appendix C
Slope Stability Results
-1 0 10 20 30
0
A
� w
a M
s o
0
.p iA A W W W W N N N N f— F' F-` F' 0 0 0 0 �
O OO (.n W O m W O m Cn W O aO (r W O CO n
t ry
0
O
r n N
V^/
mom•
o
0
O N
Ili li O
N T
N
_0 a a
o $
m W El MINIMIN
D S �
CD
to
W W
0) N
dof
O 3 3 3
O
vt
� nr
_ M3 -�
Safety Factor
0 0.0
c� 0.3
0.5
0.8
1.0
1.3
1.5 w...��. �.b w�w+r.warp• cwr. a
1.8 ro ro
uneoo.neniee wi ■ iu �e s
2.0 MV.YIF.Dlpo ■ uo
(oubmb
0 2.3
DepYU Ceubmb
2.8
ReVallon WidNlerenMed aop 3
3.0
3.3
3.5
3.8
4.0
4.3
4.5
4.8
5.0
5.3
5.5
5.8
6.0+
0
-100 0 100 200 300 400
PM)-t
SLIDE -An Interactive Slope Stability Program
r o c s c i e n c e �� a—v� A-A' Existing Seismic Conditions
OF
oEtmuwPEf9.005 I
Date 7/14/2020, 2:47:32 PM File Name DMBeIfl
Safety Factor
C 0.0
`r 0.3
0.5
0.8
1.0
1.3
1.5
1.8
...n.l•... a. vr3�3wMbew 3w.urwn/rt s...pbrn. UYtl.. rw Nlw
0 2.0 b
ch 2.3 3euMr.l9 135 MW{aAwnb 0 36
/Jluri.l fan Oepmib 115 130 MMr;g3ynb
2.5 keC pqepmin P 130 MabrCUJwnb 350 36
2.8
V� "°"' � ■ NWlnbnb 350 36
3.0
RCV.Ywn UM 1 mW4d w W MW A mb /W 37
3.3 Rap M Rebiin6 W.� ® � .�
3.5
3.8
0 4.0
N 4.3
4.5
4.8
5.0
5.3
5.5
5.8 1500.00lbs/ft2
6.0+
0
-100 0 100 200 300 400 500
Project
SLIDE -An Interactive Slope Stability Program
Anaty— A-A' Proposed Development Static Conditions
ro c s c i e n ce °ra*r ey OF Company
DEINTERPRET 9.005 Date 7/14/2020, 2:47:32 PM File Name DMBelfi
G -10 10 20 30 40
0
m
N
O (p
e O K
$ C
O O� (11 N (n (n a a � a W W W W N N N N N N F-• F-' 0 0 0 0 �
O O Ul W O W Cn W O W Cn W O W N W O W Un W O W Ln W O n
t rt
0
O
nO
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Slide Analysis Information
DMBelfairInvt.State Rt3.A A'
Project Summary
File Name: DMBelfairInvt.State Rt3.A_A'.slmd
Slide Modeler Version: 9.006
Project Title: SLIDE - An Interactive Slope Stability Program
Analysis: A-A' Existing Seismic Conditions
Author: EJF
Company: GeoResources, LLC
Date Created: 7/14/2020, 2:47:32 PM
Currently Open Scenarios
Group Name Scenario Name Global Minimum Compute Time
Existing Bishop Simplified:
Conditions - Master Scenario 1.518030 OOh:00m:01.373s
Static
Existing } Bishop Simplified:
Conditions - Master Scenario 1.059170 OOh:00m:01.299s
Seismic
Proposed "] Bishop Simplified:
Development - Master Scenario 1.900400 OOh:00m:01.310s
Static
Proposed Bishop Simplified:
Development - Master Scenario 1.286990 OOh:00m:01.299s
Seismic
DMBelfairInvt.State Rt3.A A' Friday, July 31, 2020
Analysis Options
All Open Scenarios
Slices Type: Vertical
Analysis Methods Used
Bishop simplified
Number of slices: 50
Tolerance: 0.005
Maximum number of iterations: 75
Check malpha < 0.2: Yes
Create Interslice boundaries at intersections with Yes
water tables and piezos:
Initial trial value of FS: 1
Steffensen Iteration: Yes
2/20
DMBelfairInvt.StateRt3.A_A' Friday, July 31, 2020
Surface Options
All Open Scenarios
Surface Type: Circular
Search Method: Auto Refine Search
Divisions along slope: 20
Circles per division: 10
Number of iterations: 10
Divisions to use in next iteration: 50%
Composite Surfaces: Disabled
Minimum Elevation: Not Defined
Minimum Depth: Not Defined
Minimum Area: Not Defined
Minimum Weight: Not Defined
3/20
DMBelfairInvt.StateRt3.A_A' Friday, July 31, 2020
Seismic Loading
4� Existing Conditions - Static
Advanced seismic analysis: No
Staged pseudostatic analysis: No
<> Existing Conditions - Seismic
Advanced seismic analysis: No
Staged pseudostatic analysis: No
Seismic Load Coefficient (Horizontal): 0.15
Proposed Development - Static
Advanced seismic analysis: No
Staged pseudostatic analysis: No
Proposed Development - Seismic
Advanced seismic analysis: No
Staged pseudostatic analysis: No
Seismic Load Coefficient (Horizontal): 0.15
4/20
DMBelfairInvt.State Rt3.A_A' Friday, July 31, 2020
Loading
A proposed Development - Static
Distribution: Constant
Magnitude [psf]: 1500
Orientation: Normal to boundary
Proposed Development - Seismic
Distribution: Constant
Magnitude [psf]: 1500
Orientation: Normal to boundary
5/20
DMBelfairInvt.StateRt3.A_A' Friday, July 31, 2020
Materials
Undocumented Fill
Color
Strength Type Mohr-Coulomb
Unit Weight [Ibs/ft3] 115
Cohesion [psf] 0
Friction Angle [deg] 34
Water Surface Assigned per scenario
Ru Value 0
Structural Fill
Color ■
Strength Type Mohr-Coulomb
Unit Weight [Ibs/ft3] 125
Cohesion [psf] 0
Friction Angle [deg] 36
Water Surface Assigned per scenario
Ru Value 0
Alluvial Fan Deposits
Color
Strength Type Mohr-Coulomb
Unsaturated Unit Weight [Ibs/ft3] 115
Saturated Unit Weight [Ibs/ft3] 120
Cohesion [psf] 0
Friction Angle [deg] 34
Water Surface Assigned per scenario
Hu Value Automatically Calculated
Ice Contact Deposits
Color
Strength Type Mohr-Coulomb
Unit Weight [Ibs/ft3] 130
Cohesion [psq 350
Friction Angle [deg] 36
Water Surface Assigned per scenario
Ru Value 0
Vashon Advance Outwash Deposits
Color
Strength Type Mohr-Coulomb
Unit Weight [Ibs/ft3] 130
Cohesion [psf] 350
Friction Angle [deg] 36
Water Surface Assigned per scenario
Ru Value 0
Pre-Vashon Undifferentiated
Color
Strength Type Mohr-Coulomb
Unit Weight [Ibs/ft3] 140
6/20
DMBelfairInvt.StateRt3.A_A' Friday, July 31, 2020
Cohesion [psq 800
Friction Angle [deg] 37
Water Surface Assigned per scenario
Ru Value 0
Proposed Retaining Wall
Color
Strength Type Infinite strength
Unit Weight [lbs/ft3] 20
Allow Sliding Along Boundary No
Water Surface Assigned per scenario
Ru Value 0
Materials In Use
Existing Existing Proposed Proposed
Material Conditions- Conditions - Development- Development-
Static Seismic Static Seismic
Undocumented j5
Fill
Structural Fill ■ ,/ /
Alluvial Fan f r/
Deposits
Ice Contact
Deposits
Vashon
Advance
Outwash
Deposits
Pre-Vashon
Undifferentiate
d
Proposed ® ,/
Retaining Wall
7/20
DMBelfairInvt.StateRt3.A_A' Friday, July 31, 2020
Global Minimums
!�, Existing Conditions - Static
Method: bishop simplified
FS 1.518030
Center: 633.186, 212.370
Radius: 161.051
Left Slip Surface Endpoint: 566.151, 65.933
Right Slip Surface Endpoint: 569.411, 64.484
Resisting Moment: 268.069 lb-ft
Driving Moment: 176.59 lb-ft
Total Slice Area: 0.0234772 ft2
Surface Horizontal Width: 3.25966 ft
Surface Average Height: 0.00720233 ft
Existing Conditions - Seismic
Method: bishop simplified
FS 1.059170
Center: 628.200, 195.685
Radius: 143.781
Left Slip Surface Endpoint: 568.184, 65.030
Right Slip Surface Endpoint: 571.436, 63.584
Resisting Moment: 248.425 lb-ft
Driving Moment: 234.548 lb-ft
Total Slice Area: 0.0261147 ft2
Surface Horizontal Width: 3.2521 ft
Surface Average Height: 0.00803011 ft
Proposed Development - Static
Method: bishop simplified
FS 1.900400
Center: 685.174, 397.095
Radius: 352.348
Left Slip Surface Endpoint: 557.703, 68.614
Right Slip Surface Endpoint: 560.950, 67.373
Resisting Moment: 296.716 lb-ft
Driving Moment: 156.133 lb-ft
Total Slice Area: 0.00992519 ft2
Surface Horizontal Width: 3.24627 ft
Surface Average Height: 0.00305741 ft
Proposed Development - Seismic
Method: bishop simplified
8/20
DMBelfairInvt.StateRt3.A_A' Friday, July 31, 2020
FS 1.286990
Center: 685.286, 397.495
Radius: 352.760
Left Slip Surface Endpoint: 557.667, 68.628
Right Slip Surface Endpoint: 560.915, 67.386
Resisting Moment: 280.036 lb-ft
Driving Moment: 217.589 lb-ft
Total Slice Area: 0.00992318 ft2
Surface Horizontal Width: 3.24732 ft
Surface Average Height: 0.0030558 ft
9/20
DMBelfairInvt.StateRt3.A_A' Friday, July 31, 2020
Valid and Invalid Surfaces
® Existing Conditions - Static
Method: bishop simplified
Number of Valid Surfaces: 9888
Number of Invalid Surfaces: 0
Existing Conditions - Seismic
Method: bishop simplified
Number of Valid Surfaces: 9470
Number of Invalid Surfaces: 0
Proposed Development - Static
Method: bishop simplified
Number of Valid Surfaces: 9676
Number of Invalid Surfaces: 0
<'> Proposed Development - Seismic
Method: bishop simplified
Number of Valid Surfaces: 10708
Number of Invalid Surfaces: 0
10/20
DMBelfairInvt.StateRt3.A_A' Friday,July 31, 2020
Slice Data
® Existing Conditions - Static
Global Minimum Query (bishop simplified) - Safety Factor: 1.51803
Base Base Effective Base Effective
Angle of Base Shear Shear Pore
Slice Width [ftj Weight Slice Base Base Cohesion Friction Stress Strength Normal Pressure Normal Vertical Vertical
Number [lbs] Material Angle Stress Stress Stress Stress
[deg] iPsll [deg] iPsn iPsn [Psn [n3Q IPA IPA lPsfl
1 0.0651933 0.0031914 -24.5843 Undocume 0 34 0.0180801 0.0274462 0.0406906 0 0.0406906 0.0489624 0.0489624
8 nted Fill
2 0.0651933 0.0094429 -24.5588 Undocume 0 34 0.053506 0.0812237 0.120419 0 0.120419 0.144869 0.144869
1 nted Fill
3 0.0651933 0.0154314 -24.5333 Undocume 0 34 0.0874555 0.13276 0.196825 0 0.196825 0.236743 0.236743
nted Fill
4 0.0651933 0.0211571 -24.5078 Undocume 0 34 0.119929 0.182056 0.26991 0 0.26991 0.324584 0.324594
nted Fill
5 0.0651933 0.0266201 -24.4823 Undocume 0 34 0.150927 0.229111 0.33967 0 0.33967 0.408395 0.408395
nted Fill
6 0.0651933 0.0318207 -24.4568 Undocume 0 34 0.180447 0.273924 0.406109 0 0.406109 0.488179 0.488179
nted Fill
7 0.0651933 0.0367589 -24.4313 Undocume 0 34 0.208492 0.316497 0.469227 0 0.469227 0.563941 0.563941
nted Fill
8 0.0651933 0.041435 -24.4059 Undocume 0 34 0,235061 0.35683 0.529021 0 0.529021 0.635679 0.635679
nted Fill
9 0.0651933 0.0458491 -24.3804 Undocume 0 34 0.260154 0.394921 0.585494 0 0.585494 0.703398 0.703398
nted Fill
10 0.0651933 0.0500013 -24.3549 Undocume 0 34 0,28377 0.430772 0.638645 0 0.638645 0.7671 0.7671
nted Fill
11 0.0651933 0.0538919 -24.3295 Undocume 0 34 0,305911 0.464382 0.689475 0 0,688475 0.826788 0.826788
nted Fill
12 0.0651933 0.057521 -24.304 Undocume 0 34 0.326575 0.495751 0.73498 0 0.73498 0.882462 0.882462
nted Fill
13 0.0651933 0.0608886 -24.2786 Undocume 0 34 0.345763 0.524879 0.778165 0 0.778165 0,934128 0.934128
nted Fill
14 0.0651933 0.0639951 -24.2531 Undocume 0 34 0.363476 0.551767 0.818028 0 0.818028 0.981786 0.981786
nted Fill
15 0.0651933 0.0668405 -24.2277 Undocume 0 34 0.379712 0.576414 0.854569 0 0.854569 1.02544 1.02544
nted Fill
16 0.0651933 0.069425 -24.2023 Undocume 0 34 0.394472 0.59882 0.887788 0 0.887788 1.06509 1.06509
nted Fill
17 0.0651933 0.0717488 -24.1768 Undocume 0 34 0.407756 0.618986 0.917685 0 0.917685 1.10074 1.10074
nted Fill
18 0.0651933 0.073812 -24.1514 Undocume 0 34 0.419564 0.636911 0.944259 0 0.944259 1.13239 1.13239
nted Fill
19 0.0651933 0.0756147 -24.126 Undocume 0 34 0.429896 0.652595 0.967512 0 0.967512 1.16005 1.16005
nted Fill
20 0.0651933 0.0771572 -24.1006 Undocume 0 34 0.438752 0.666039 0.987443 0 0,987443 1.18371 1.18371
nted Fill
11/20
DMBelfairInvt.StateRt3.A_A' Friday, July 31, 2020
21 0.0651933 0.0784395 -24.0752 Undocume 0 34 0.446132 0.677242 1.00405 0 1.00405 1.20339 1.20339
nted Fill
22 0.0651933 0.0794619 -24.0498 Undocume 0 34 0.452036 0.686204 1.01734 0 1.01734 1.21907 1.21907
nted Fill
23 0.0651933 0.0802245 -24.0244 Undocume 0 34 0.456464 0.692926 1.0273 0 1.0273 1.23077 1.23077
nted Fill
24 0.0651933 0.0807274 -23.999 Undocume 0 34 0.459416 0.697407 1.03395 0 1.03395 113849 1.23849
nted Fill
25 0.0651933 0.0809709 -23.9736 Undocume 0 34 0.460892 0.699648 1.03727 0 1.03727 1.24222 1.24222
nted Fill
26 0.0651933 0.0809549 -23.9482 Undocume 0 34 0.460892 0.699648 1.03727 0 1.03727 1.24197 1.24197
nted Fill
27 0.0651933 0,0806798 -23.9229 Undocume 0 34 0.459416 0.697407 1.03395 0 1.03395 1.23775 1.23775
nted Fill
28 0.0651933 0.0801456 -23.8975 Undocume 0 34 0,456464 0.692926 1.02731 0 1.02731 1.22956 1.22956
nted Fill
29 0.0651933 0.0793526 -23.8721 Undocume 0 34 0.452036 0.686204 1.01734 0 1.01734 1.21739 1.21739
nted Fill
30 0.0651933 0.0783008 -23.8468 Undocume 0 34 0.446132 0.677242 1.00405 0 1.00405 1.20125 1.20125
nted Fill
31 0.0651933 0.0769904 -23.8214 Undocume 0 34 0.438752 0.666039 0.987443 0 0.987443 1.18115 1,18115
nted Fill
32 0.0651933 0.0754216 -23.7961 Undocume 0 34 0.429896 0.652595 0.967512 0 0,967512 1.15708 1.15708
nted Fill
33 0.0651933 0.0735945 -23.7707 Undocume 0 34 0.419564 0.63691 0.944259 0 0.944259 1.12905 1.12905
nted Fill
34 0.0651933 0.0715092 -23.7454 Undocume 0 34 0.407756 0.618986 0.917683 0 0.917683 1.09706 1.09706
nted Fill
35 0.0651933 0.069166 -23.72 Undocume 0 34 0.394472 0.59882 0.887787 0 0.887787 1.06111 1.06111
nted Fill
36 0.0651933 0.066565 -23.6947 Undocume 0 34 0.379712 0.576414 0.854568 0 0.854568 1.02121 1.02121
nted Fill
37 0.0651933 0.0637062 -23,6694 Undocume 0 34 0.363476 0.551767 0.818027 0 0.818027 0,97735 0,97735
nted Fill
38 0.0651933 0.06059 -23.6441 Undocume 0 34 0.345763 0.524879 0.778166 0 0.778166 0.929543 0.929543
nted Fill
39 0.0651933 0.0572163 -23.6187 Undocume 0 34 0.326575 0.495751 0.734981 0 0.734981 0.877785 0.877785
nted Fill
40 0.0651933 0.0535855 -23.5934 Undocume 0 34 0.305911 0.464382 0.688475 0 0.688475 0.822083 0.822083
nted Fill
41 0.0651933 0,0496975 -23.5681 Undocume 0 34 0.28377 0.430772 0.638646 0 0.638646 0.762434 0.762434
nted Fill
42 0.0651933 0.0455526 -23.5428 Undocume 0 34 0.260154 0.394922 0.585496 0 0.585496 0.698845 0.698845
nted Fill
43 0.0651933 0.0411509 -23.5175 Undocume 0 34 0.235062 0.356831 0.529024 0 0.529024 0.631317 0.631317
nted Fill
44 0.0651933 0.0364926 -23.4922 Undocume 0 34 0.208493 0.316499 0.46923 0 0.46923 0.559851 0.559851
nted Fill
45 0.0651933 0.0315778 -23.4669 Undocume 0 34 0.180449 0.273927 0.406113 0 0.406113 0.484451 0.484451
nted Fill
12/20
DMBelfairInvt.StateRt3.A_A' Friday,July 31, 2020
46 0.0651933 0.0264066 -23.4417 Undocume 0 34 0.150928 0.229113 0.339675 0 0.339675 0.405117 0.405117
nted Fill
47 0.0651933 0.0209792 -23.4164 Undocume 0 34 0.119931 0.182059 0.269913 0 0.269913 0.321852 0.321852
nted Fill
48 0.0651933 0.0152958 -23.3911 Undocume 0 34 0.0874581 0.132764 0.19683 0 0.19683 0.23466 0.23466
nted Fill
49 0.0651933 0.0093565 -23.3658 Undocume 0 34 0.0535089 0.0812281 0.120426 0 0.120426 0.143543 0.143543
2 nted Fill
50 0.0651933 0.0031614 -23.3406 Undocume 0 34 0.0180835 0.0274513 0.0406982 0 0.0406982 0.0485014 0.0485014
5 nted Fill
13/20
DMBelfairInvt.StateRt3.A_N Friday, July 31, 2020
A Existing Conditions - Seismic
Global Minimum Query(bishop simplified) - Safety Factor: 1.05917
Base Base Effective Base Effective
Angle of Base Shear Shear Pore
Slice Width Ift] Weight Slice Base Base Cohesion Friction Stress Strength Normal Pressure Normal Vertical Vertical
Number Ilbs] Material Angle Stress Stress Stress Stress
Ideg] IPsfl Ideg] IPsfl IPsfl Ipsf] IPsfl IPsfl IPsfl IPA
1 0.0650419 0.0035520 -24,6573 Undocume 0 34 0.0269117 0.0285041 0.0422591 0 0.0422591 0.0546129 0,0546129
2 nted Fill
2 0.0650419 0.0105095 -24.6288 Undocume 0 34 0.0796485 0.0843613 0.125071 0 0.125071 0.161585 0.161585
nted Fill
3 0.0650419 0.017174 -24.6003 Undocume 0 34 0.130195 0.137899 0.204444 0 0.204444 0.264053 0.264053
nted Fill
4 0.0650419 0.0235457 -24.5718 Undocume 0 34 0.178552 0.189117 0.280377 0 0.280377 0.362019 0.362019
nted Fill
5 0.0650419 0.0296249 -24.5433 Undocume 0 34 0.224718 0.238015 0.352871 0 0.352871 0.455486 0.455486
nted Fill
6 0.0650419 0.0354116 -24.5148 Undocume 0 34 0.268692 0.294591 0.421924 0 0.421924 0.544458 0.544458
nted Fill
7 0.0650419 0.0409061 -24.4863 Undocume 0 34 0.310476 0.328847 0.487535 0 0.487535 0.628938 0.628938
nted Fill
8 0.0650419 0.0461087 -24.4579 Undocume 0 34 0.350067 0.37078 0.549705 0 0.549705 0.708929 0.708929
nted Fill
9 0.0650419 0.0510195 -24.4294 Undocume 0 34 0.387466 0.410392 0.60843 0 0.60843 0.784432 0.794432
nted Fill
10 0.0650419 0.0556387 -24.4009 Undocume 0 34 0.422671 0.44768 0.663713 0 0.663713 0.855453 0.855453
nted Fill
11 0.0650419 0.0599664 -24.3725 Undocume 0 34 0.455682 0.482645 0.715551 0 0,715551 0.921993 0.921993
nted Fill
12 0.0650419 0.064003 -24.344 Undocume 0 34 0.4865 0.515286 0.763943 0 0.763943 0.984056 0.984056
nted Fill
13 0.0650419 0.0677486 -24.3156 Undocume 0 34 0.515123 0.545603 0.80889 0 0.80889 1.04165 1.04165
nted Fill
14 0.0650419 0.0712034 -24.2871 Undocume 0 34 0.541551 0.573595 0.850389 0 0.850389 1.09476 1.09476
nted Fill
15 0.0650419 0.0743675 -24.2587 Undocume 0 34 0,565784 0.599261 0.888442 0 0.888442 1.14341 1.14341
nted Fill
16 0.0650419 0.0772413 -24.2303 Undocume 0 34 0.587821 0.622602 0.923045 0 0.923045 1.1876 1.1876
nted Fill
17 0.0650419 0.0798248 -24.2019 Undocume 0 34 0.607661 0.643616 0.9542 0 0.9542 1.22732 1.22732
nted Fill
18 0.0650419 0.0821183 -24.1734 Undocume 0 34 0.625305 0,662304 0.981906 0 0,981906 1.26258 1.26258
nted Fill
19 0.0650419 0.0841219 -24.145 Undocume 0 34 0.640751 0.678664 1.00616 0 1.00616 1.29339 1.29339
nted Fill
20 0.0650419 0.085836 -24.1166 Undocume 0 34 0.653999 0.692696 1.02696 0 1.02696 1.31974 1.31974
nted Fill
21 0.0650419 0.0872605 -24.0882 Undocume 0 34 0.665049 0.7044 1.04432 0 1.04432 1.34164 1.34164
nted Fill
22 0.0650419 0.0883958 -24.0598 Undocume 0 34 0.6739 0.713775 1.05821 0 1.05821 1.3591 1.3591
nted Fill
14/20
DMBelfairInvt.StateRt3.A_A' Friday, July 31, 2020
23 0.0650419 0.0892421 -24.0315 Undocume 0 34 0.680553 0.720821 1.06866 0 1.06866 1.37211 1.37211
nted Fill
24 0.0650419 0.0897995 -24.0031 Undocume 0 34 0.685004 0.725536 1.07565 0 1.07565 1.38068 1,38068
nted Fill
25 0.0650419 0.0900681 -23.9747 Undocume 0 34 0.687256 0.727921 1.07919 0 1.07919 1.38481 1.38481
nted Fill
26 0.0650419 0.0900494 -23.9464 Undocume 0 34 0.687307 0.727975 1.07927 0 1.07927 1.38451 1.38451
nted Fill
27 0.0650419 0.0897403 -23.918 Undocume 0 34 0.685157 0.725698 1.07589 0 1.07589 1.37977 1.37977
nted Fill
28 0.0650419 0.089144 -23.8897 Undocume 0 34 0.680806 0.721089 1.06906 0 1.06906 1.3706 1.3706
nted Fill
29 0.0650419 0.0882599 -23.8613 Undocume 0 34 0.674252 0.714147 1.05877 0 1.05877 1.35701 1.35701
nted Fill
30 0.0650419 0.0870881 -23.833 Undocume 0 34 0.665495 0.704872 1.04502 0 1.04502 1.33899 1.33899
nted Fill
31 0.0650419 0.0856287 -23.8046 Undocume 0 34 0.654534 0.693263 1.02781 0 1.02781 1.31655 1.31655
nted Fill
32 0.0650419 0.0838819 -23.7763 Undocume 0 34 0.641371 0.679321 1.00713 0 1.00713 1.2897 1.2897
nted Fill
33 0.0650419 0.081948 -23.748 Undocume 0 34 0.626002 0.663043 0.983002 0 0.983002 1.25842 1.25842
nted Fill
34 0.0650419 0.0795271 -23.7197 Undocume 0 34 0.60943 0.644431 0.955408 0 0.955408 1,22274 112274
nted Fill
35 0.0650419 0.0769194 -23.6914 Undocume 0 34 0.588652 0.623483 0.924352 0 0.924352 1.18265 1.18265
nted Fill
36 0.0650419 0.0740251 -23.6631 Undocume 0 34 0.566668 0.600198 0.889831 0 0.889831 1.13815 1.13815
nted Fill
37 0.0650419 0.0708443 -23.6348 Undocume 0 34 0.542479 0.574577 0.851846 0 0.851846 1.08924 1.08924
nted Fill
38 0.0650419 0.0673774 -23.6065 Undocume 0 34 0.516082 0.546619 0.810396 0 0.810396 1.03594 1.03594
nted Fill
39 0.0650419 0.0636244 -23.5782 Undocume 0 34 0.487479 0.516323 0.76548 0 0.76548 0.978234 0.978234
nted Fill
40 0.0650419 0.0595855 -23.5499 Undocume 0 34 0.456667 0.483688 0.717097 0 0.717097 0.916135 0.916135
nted Fill
41 0.0650419 0.055261 -23.5217 Undocume 0 34 0.423648 0.448715 0.665247 0 0.665247 0.849645 0,849645
nted Fill
42 0.0650419 0.0506509 -23.4934 Undocume 0 34 0.388419 0,411402 0.609928 0 0.609928 0.778764 0,778764
nted Fill
43 0.0650419 0.0457556 -23.4651 Undocume 0 34 0.350981 0.371749 0.551141 0 0.551141 0.703498 0.703498
nted Fill
44 0.0650419 0.0405751 -23.4369 Undocume 0 34 0.311334 0.329756 0,488882 0 0.488882 0.623947 0,623947
nted Fill
45 0.0650419 0.0351096 -23.4086 Undocume 0 34 0.269476 0.285421 0.423154 0 0.423154 0.539815 0.539815
nted Fill
46 0.0650419 0.0293595 -23.3804 Undocume 0 34 0.225408 0.238745 0.353955 0 0.353955 0.451406 0.451406
nted Fill
47 0.0650419 0.0233247 -23.3522 Undocume 0 34 0.179128 0.189727 0,281283 0 0.281283 0.358621 0.358621
nted Fill
15/20
DMBelfairInvLStateRt3.A_A' Friday, July 31, 2020
48 0.0650419 0.0170055 -23.3239 Undocume 0 34 0.130636 0.138366 0.205136 0 0.205136 0.261462 0.261462
nted Fill
49 0.0650419 0.0104021 -23.2957 Undocume 0 34 0.0799325 0.0846621 0,125517 0 0.125517 0.159934 0.159934
nted Fill
50 0.0650419 0.0035147 -23.2675 Undocume 0 34 0.0270157 0.0286142 0.0424223 0 0.0424223 0.0540389 0.0540389
nted Fill
16/20
DM13elfairInvt.StateRt3.A A' Friday, July 31, 2020
A Proposed Development - Static
Global Minimum Query(bishop simplified) -Safety Factor: 1.9004
Base Base Effective Base Effective
Angle of Base Shear Shear Pore
Slice Width jft] Weight Slice Base Base Cohesion Friction Stress Strength Normal Pressure Normal Vertical Vertical
Number jlbsj Material Angle Stress Stress Stress Stress
]deg, IPsq [deg] IPA IPsfl 1Psq 1Pgq IPs11 1Psf1 1psq
1 0.0649255 0.0014622 -21.2036 Structural 0 36 0.0074996 0.0142523 0.0196166 0 0.0196166 0.022526 0.022526
4 Fill 3
2 0.0649255 0.0043268 -21.1923 Structural 0 36 0.0221934 0.0421763 0.0580506 0 0.0580506 0.0666555 0.0666555
2 Fill
3 0.0649255 0.0070716 -21.181 Structural 0 36 0.0362748 0.0689367 0,0948832 0 0.0948832 0.108939 0.108939
1 Fill
4 0.0649255 0.0096966 -21.1697 Structural 0 36 0.0497441 0.0945337 0.130114 0 0.130114 0.149379 0.149379
4 Fill
5 0.0649255 0.0122019 -21.1583 Structural 0 36 0.062601 0.118967 0.163745 0 0.163745 0.187974 0.187974
Fill
6 0.0649255 0.0145875 -21.147 Structural 0 36 0.0749458 0.142237 0.195773 0 0.195773 0,224724 0.224724
Fill
7 0.0649255 0,0168534 -21,1357 Structural 0 36 0.0864781 0.164343 0.226199 0 0.226199 0.25963 0.25963
Fill
8 0.0649255 0.0189997 -21.1244 Structural 0 36 0.0974984 0.185286 0.255024 0 0.255024 0.292693 0.292693
Fill
9 0.0649255 0.0210263 -21.1131 Structural 0 36 0.107907 0.205066 0.282249 0 0.282249 0.323915 0.323915
Fill
10 0.0649255 0.0229334 -21.1017 Structural 0 36 0.117702 0.223681 0.307871 0 0.307871 0.353292 0.353292
Fill
11 0.0649255 0.0247208 -21.0904 Structural 0 36 0.126886 0.241134 0.331892 0 0.331892 0.380829 0.380829
Fill
12 0.0649255 0.0263888 -21.0791 Structural 0 36 0.135457 0.257423 0.354312 0 0.354312 0.406524 0.406524
Fill
13 0.0649255 0.0279372 -21.0678 Structural 0 36 0.143416 0.272548 0.375129 0 0.375129 0.430376 0.430376
Fill
14 0.0649255 0.0293661 -21.0565 Structural 0 36 0.150763 0.28651 0.394347 0 0.394347 0.45239 0.45239
Fill
15 0.0649255 0.0306756 -21.0452 Structural 0 36 0.157497 0.299308 0.411962 0 0.411962 0.472562 0.472562
Fill
16 0.0649255 0.0318656 -21.0339 Structural 0 36 0.16362 0.310943 0.427976 0 0.427976 0.490895 0.490895
Fill
17 0.0649255 0.0329362 -21.0225 Structural 0 36 0.16913 0.321414 0.442389 0 0,442389 0.507388 0.507388
Fill
18 0.0649255 0.0338875 -21.0112 Structural 0 36 0.174028 0.330722 0.4552 0 0.4552 0.522042 0.522042
Fill
19 0.0649255 0.0347194 -20.9999 Structural 0 36 0.178314 0.338867 0.46641 0 0.46641 0.534858 0.534858
Fill
20 0.0649255 0.035432 -20.9886 Structural 0 36 0.181986 0.345847 0.476019 0 0.476019 0.545835 0.545835
Fill
21 0.0649255 0.0360252 -20.9773 Structural 0 36 0.185048 0.351665 0.484025 0 0.484025 0.554974 0.554974
Fill
22 0.0649255 0.0364992 -20.966 Structural 0 36 0.187497 0.356319 0.490431 0 0.490431 0.562277 0.562277
Fill
23 0.0649255 0.036854 -20,9547 Structural 0 36 0,189333 0.359809 0.495235 0 0.495235 0.567742 0.567742
Fill
24 0.0649255 0.0370995 -20.9434 Structural 0 36 0.190558 0.362136 0.498437 0 0.498437 0.57137 0.57137
Fill
25 0.0649255 0.0372059 -20.9321 Structural 0 36 0.19117 0.3633 0.500039 0 0.500039 0.573162 0.573162
Fill
26 0.0649255 0.0372031 -20.9208 Structural 0 36 0.19117 0.3633 0.500039 0 0.500039 0.573119 0.573119
Fill
27 0.0649255 0.0370812 -20.9095 Structural 0 36 0.190558 0.362136 0.499438 0 0.499438 0.571241 0.571241
Fill
28 0.0649255 0.0368401 -20.8982 Structural 0 36 0.189333 0.359809 0.495235 0 0.495235 0.567527 0.567527
Fill
29 0.0649255 0.03648 -20.8869 Structural 0 36 0.187497 0.356319 0.49043 0 0.49043 0.561979 0.561979
Fill
30 0.0649255 0.0360008 -20.8756 Structural 0 36 0.185048 0.351665 0.484025 0 0.494025 0.554598 0.554598
Fill
17/20
DMBelfairInvt.StateRt3.A_A' Friday, July 31, 2020
"31 0.0649255 0.0354026 -20.8643 Structural 0 36 0.181986 0.345847 0,476018 0 0.476018 0.545382 0.545382
Fill
32 0.0649255 0.0346854 -20.853 Structural 0 36 0.178313 0.338866 0.46641 0 0.46641 0.534334 0,534334
Fill
33 0.0649255 0.0338492 -20.8417 Structural 0 36 0.174028 0.330722 0.4552 0 0.4552 0.521452 0.521452
Fill
34 0.0649255 0.0328941 -20,8304 Structural 0 36 0.16913 0.321414 0.442389 0 0.442389 0.506738 0.506738
Fill
35 0.0649255 0.03182 -20.8191 Structural 0 36 0.16362 0.310943 0.427975 0 0.427975 0.490191 0.490191
Fill
36 0.0649255 0.0306271 -20.8078 Structural 0 36 0.157497 0.299308 0.411963 0 0.411963 0.471815 0.471815
Fill
37 0.0649255 0.0293153 -20.7965 Structural 0 36 0.150763 0.28651 0.394346 0 0.394346 0.451605 0.451605
Fill
38 0.0649255 0.0278846 -20.7852 Structural 0 36 0.143416 0.272548 0.37513 0 0.37513 0.429567 0.429567
Fill
39 0.0649255 0.0263351 -20.7739 Structural 0 36 0.135457 0.257422 0.354312 0 0.354312 0.405696 0.405696
Fill
40 0.0649255 0.0246669 -20.7626 Structural 0 36 0.126886 0.241134 0.331891 0 0.331891 0.379996 0.379996
Fill
41 0.0649255 0.0228799 -20.7513 Structural 0 36 0.117702 0.223681 0.307872 0 0.307872 0.352468 0.352468
Fill
42 0.0649255 0.0209741 -20.7401 Structural 0 36 0.107907 0.205066 0.282248 0 0.282248 0.323109 0.323109
Fill
43 0.0649255 0.0189497 -20.7288 Structural 0 36 0.0974994 0.185286 0.255024 0 0.255024 0.291922 0.291922
Fill
44 0.0649255 0.0168065 -20.7175 Structural 0 36 0.0864781 0.164343 0.226199 0 0.226199 0.258907 0.258907
Fill
45 0.0649255 0.0145448 -20.7062 Structural 0 36 0.0748458 0.142237 0.195773 0 0.195773 0.224064 0.224064
Fill
46 0.0649255 0.0121643 -20.6949 Structural 0 36 0.062601 0.118967 0.163745 0 0.163745 0.187393 0.187393
Fill
47 0.0649255 0.0096653 -20.6836 Structural 0 36 0.0497443 0.0945341 0.130115 0 0.130115 0.148896 0.148896
4 Fill
48 0.0649255 0.0070477 -20.6723 S�'chr� 0 36 0.0362752 0.0689374 0.0948842 0 0.0948942 0.108571 0.108571
5 Fill
49 0.0649255 0.0043116 -20.661 Structural 0 36 0.0221938 0.0421771 0.0580518 0 0.0580518 0.0664209 0.0664209
1 Fill
50 0.0649255 0.0014569 -20.6498 Structural 0 36 0.0075001 0.0142533 0.019618 0 0.019618 0.0224446 0.0224446
6 Fill 6
18/20
DMBelfairInvt.StateRt3.A_A' Friday, July 31, 2020
Proposed Development - Seismic
h
Global Minimum Query(bishop simplified) -Safety Factor: 1.28699
Base Base Effective Base Effective
Angle of Base Shear Shear Pore
Slice Width jft] Weight Slice Base Base Cohesion Friction Stress Strength Normal Pressure Normal Vertical Vertical
Number jibs] Material Angle Stress Stress Stress Stress
Ideal IPS11 ideal [PS11 [PSq IPA [PSI] iPsfl IPA IPA
1 0.0649465 0.0014619 -21.2034 Structural 0 36 0.0104285 0.0134214 0.0194729 0 0.0184729 0.0225186 0.0225186
4 Fill
2 0.0649465 0.0043259 -21.1921 Structural 0 36 0.0308615 0.0397185 0.0546678 0 0.0546678 0.0666333 0.0666333
4 Fill
3 0.0649465 0.0070701 -21.1808 Structural 0 36 0.0504444 0.0649214 0.0893565 0 0.0893565 0.108903 0.108903
7 Fill
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19/20
DMBelfairInvt.StateRt3.A X Friday, July 31, 2020
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20/20
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