HomeMy WebLinkAbout3.31b MOB - VMC Geo ReportGeotechnical Engineering Services
Valley Medical Center FY 2017
Proposed Medical Office Building
Renton, Washington
for
Valley Medical Center
September 16, 2016
Geotechnical Engineering Services
Valley Medical Center FY 2017
Proposed Medical Office Building
Renton, Washington
for
Valley Medical Center
September 16, 2016
8410 154th Avenue NE
Redmond, Washington 98052
425.861.6000
Table of Contents
INTRODUCTION ............................................................................................................................................. 1
PROJECT DESCRIPTION ............................................................................................................................... 1
FIELD EXPLORATIONS AND LABORATORY TESTING ................................................................................. 1
Field Explorations ................................................................................................................................... 1
Laboratory Testing ................................................................................................................................. 1
PREVIOUS SITE EVALUATIONS .................................................................................................................... 1
SITE CONDITIONS ......................................................................................................................................... 2
Regional Geology ................................................................................................................................... 2
Surface Conditions................................................................................................................................. 2
Subsurface Conditions .......................................................................................................................... 2
Fill……… ............................................................................................................................................ 2
Glacially Consolidated Soils ............................................................................................................ 3
Sandstone Bedrock ......................................................................................................................... 3
Groundwater Conditions ........................................................................................................................ 3
CONCLUSIONS AND RECOMMENDATIONS ................................................................................................ 3
Earthquake Engineering ........................................................................................................................ 4
Liquefaction ..................................................................................................................................... 4
Lateral Spreading ............................................................................................................................ 4
Surface Rupture .............................................................................................................................. 4
Other Seismic Hazards ................................................................................................................... 4
2012 IBC Seismic Design Information .......................................................................................... 4
Excavations ............................................................................................................................................ 5
Excavation Considerations ............................................................................................................. 5
Temporary Cut Slopes ..................................................................................................................... 5
Shallow Foundations ............................................................................................................................. 5
Allowable Bearing Pressure ............................................................................................................ 6
Settlement ....................................................................................................................................... 7
Lateral Resistance .......................................................................................................................... 7
Construction Considerations .......................................................................................................... 7
Slab-on-Grade Floors ............................................................................................................................. 7
Subgrade Preparation ..................................................................................................................... 7
Design Parameters ......................................................................................................................... 8
Below-Slab Drainage ....................................................................................................................... 8
Below-Grade Walls ................................................................................................................................. 9
Other Cast-in-Place Walls ............................................................................................................... 9
Drainage ........................................................................................................................................ 10
Earthwork ............................................................................................................................................. 10
Stripping, Clearing and Grubbing ................................................................................................. 10
Erosion and Sedimentation Control ............................................................................................. 10
Subgrade Preparation ................................................................................................................... 11
Structural Fill ................................................................................................................................. 11
September 16, 2016 | Page i File No. 2202-024-00
Table of Contents (continued)
Permanent Slopes ......................................................................................................................... 13
Pavement Design ................................................................................................................................. 13
Subgrade Preparation ................................................................................................................... 13
New Hot-Mix Asphalt Pavement ................................................................................................... 14
Infiltration ............................................................................................................................................. 14
Recommended Additional Geotechnical Services ............................................................................. 15
LIMITATIONS ............................................................................................................................................... 15
REFERENCES .............................................................................................................................................. 15
LIST OF FIGURES
Figure 1. Vicinity Map
Figure 2. Site Plan
APPENDICES
Appendix A. Field Explorations
Figure A-1 – Key to Exploration Logs
Figures A-2 through A-5 Boring Logs
Appendix B. Laboratory Testing
Figure B-1 – Sieve Analysis Results
Appendix C. Boring Logs from Previous Studies
Appendix D. Report Limitations and Guidelines
September 16, 2016 | Page ii File No. 2202-024-00
INTRODUCTION
This report presents the results of GeoEngineers’ geotechnical engineering services for the Valley Medical
Center (VMC) Fiscal Year (FY) 2017 Medical Office Building project in Renton, Washington. The site is
trapezoidal in shape and is located in the northern portion of the VMC campus at 400 South 43rd Street.
The site is bordered to the west by an existing medical office building, to the north by a VMC campus access
road off Talbot Road South, to the east by a parking lot and to the south by the VMC. The site is shown
relative to surrounding physical features on the Vicinity Map, Figure 1 and the Site Plan, Figure 2.
The purpose of this report is to provide geotechnical engineering conclusions and recommendations for the
design and construction of the planned medical office building development. GeoEngineers’ geotechnical
engineering services have been completed in general accordance with our signed agreement executed on
March 21, 2016.
PROJECT DESCRIPTION
GeoEngineers understands that Medical Office Building project will consist of up to eight levels above-grade
and the ground floor will be at or partially below-grade.
Based on our understanding of the project, temporary slope cuts along the perimeter of the proposed
building will be sufficient to complete the excavation. Variable soil conditions are present at the anticipated
foundation elevation; therefore, shallow foundations bearing on native or structural fill are anticipated for
foundation support.
FIELD EXPLORATIONS AND LABORATORY TESTING
Field Explorations
The subsurface conditions at the site were evaluated by drilling four borings, GEI-8 through GEI-11, to
depths of approximately 21 to 26½ feet below existing site grades. The approximate locations of the
explorations are shown on the Site Plan, Figure 2. Descriptions of the field exploration program and the
boring logs are presented in Appendix A.
Laboratory Testing
Soil samples were obtained during drilling and were taken to GeoEngineers’ laboratory for further
evaluation. Selected samples were tested for soil moisture content, the determination of fines content and
grain-size distribution (sieve analysis). A description of the laboratory testing and the test results are
presented in Appendix B.
PREVIOUS SITE EVALUATIONS
In addition to the explorations completed as part of this evaluation, the logs of selected explorations from
previous site evaluations in the project vicinity were reviewed. The logs of explorations from previous
projects referenced for this study are presented in Appendix C.
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SITE CONDITIONS
Regional Geology
Published geologic information for the project vicinity includes a geologic map of the Renton Quadrangle
(Mullineaux 1965). The geologic map of the project area identifies subsurface soils to consist primarily of
glacial till deposits of the Vashon Drift. Also mapped in the area are Renton Formation sandstone with
interbeds of siltstone, claystone and coal.
Glacial till typically consists of a heterogeneous mixture of sand, gravel, cobbles and occasional boulders
in a silt and clay matrix that was deposited beneath a glacier. Because glacial till has been overridden by
thousands of feet of ice, it is typically dense to very dense.
Renton Formation sandstone consists of irregularly cemented arkosic sandstone, mudstone and shale and
locally contains coal deposits. Geologic map notes maximum thicknesses of approximately 2,500 feet.
Subsurface soils encountered in our explorations are consistent with the geologic mapping. Specific
details of subsurface conditions encountered in the field explorations are presented in the “Subsurface
Conditions” section below.
Surface Conditions
The site is currently occupied by asphalt surface parking, landscaped parking islands and several mature
coniferous and deciduous trees. The site steps down from east to west, with a total change in elevation of
approximately 9 feet.
Generally, the site appears to be clear of public utilities. The utilities on site consist of private stormwater
and power for the parking lot lights.
Subsurface Conditions
The subsurface conditions at the site were evaluated by completing four geotechnical borings (GEI-8
through GEI-11) for the current study, and reviewing logs of explorations completed by GeoEngineers
immediately adjacent to the project site as part of the proposed parking garage as well as other explorations
by others in the project vicinity. The approximate locations of the explorations in the site vicinity are shown
on the Site Plan, Figure 2.
The soil units encountered in the explorations consist of fill, glacially consolidated soils and sandstone
bedrock, as described below. Asphalt concrete pavement was encountered at the ground surface at each
boring location and ranged in thickness from 1½ to 3 inches. The asphalt concrete pavement was underlain
with up to 5½ inches of base course consisting of crushed gravel, where encountered.
Fill
Fill was encountered below the asphalt pavement in the explorations completed for this study and previous
studies. The fill typically consists of loose to medium dense silty sand with variable gravel content and
extends to depths ranging from ½ to 9½ feet below existing site grades. The deepest fill, approximately
9½ feet, was encountered in boring GEI-10. The other borings in the building footprint (GEI-8, GEI-9, and
GEI-11) encountered shallow fill up to 2 feet thick.
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Glacially Consolidated Soils
The glacially consolidated soils encountered below the fill consist of weathered and unweathered glacial
till. The glacial till encountered consists of silty sand or sandy silt with variable gravel content. A dense to
very dense weathered zone near the surface transitions to the dense to very dense/hard unweathered
glacial till below. The transition between weathered and unweathered glacial till was observed at depths
ranging from approximately 5 to 9 feet below site grades.
Glacial till extended approximately 20½ feet below site grades in boring GEI-10 and to the depths explored
in borings GEI-8, GEI-9 and GEI-11.
Sandstone Bedrock
Sandstone bedrock (Renton Formation) was encountered below the glacially consolidated soils in boring
GEI-10 and consists of very dense cemented silty sand with occasional coal deposits. Where encountered,
the Renton formation extended to the depths explored.
Groundwater Conditions
Perched water was encountered at various depths in borings GEI-9 and GEI-10. The groundwater observed
in GEI-10 was confined to wet, medium dense soils overlying dense to very dense soils with relatively high
fines content. The perched groundwater encountered is likely associated with seasonal rainfall. Perched
groundwater is expected to fluctuate as a result of season, precipitation, and other factors.
CONCLUSIONS AND RECOMMENDATIONS
A summary of the primary geotechnical considerations is provided below. The summary is presented for
introductory purposes only and should be used in conjunction with the complete recommendations
presented in this report.
■ The site is designated as Site Class C per ASCE/SEI 7-10 and the 2012 International Building
Code (IBC).
■ The groundwater table is likely well below the base of the excavation. Minor seepage inflows may be
expected where excavations intercept perched groundwater zones. We estimate flow rates from
incidental seepage may be on the order of 5 to 10 gallons per minute (gpm).
■ Temporary excavations may be completed with temporary open cuts.
■ Shallow foundations may be used and shall bear on either dense to very dense/hard glacial till, on
structural fill extending down to dense to very dense/hard glacial till, or on a 2-foot-thick layer of
structural fill placed over the existing fill and highly weathered glacial soils:
For shallow foundations bearing directly on dense to very dense/hard glacial till, an allowable
soil bearing pressure of 10 kips per square foot (ksf) may be used.
For shallow foundations bearing on structural fill extending down to dense to very dense/hard
glacial till, an allowable soil bearing pressure of 6 ksf may be used.
For shallow foundations bearing on a 2-foot-thick layer of structural fill placed over the existing
fill and highly weathered glacial soils, an allowable soil bearing pressure of 3 ksf may be used.
September 16, 2016 | Page 3 File No. 2202-024-00
■ The majority of the on-site soils generally contain a high percentage of fines and are highly moisture-
sensitive. The on-site soils may be used as structural fill during dry weather conditions only (typically
June through September) provided the soils are properly moisture conditioned for compaction.
Imported granular soils with a low percentage of fines should be used as structural fill during wet
weather conditions and during the wet season (typically October through May).
Our specific geotechnical recommendations are presented in the following sections of this report.
Earthquake Engineering
Liquefaction
Liquefaction refers to the condition by which vibration or shaking of the ground, usually from earthquake
forces, results in the development of excess pore pressures in saturated soils with subsequent loss of
strength. In general, soils that are susceptible to liquefaction include very loose to medium dense, clean to
silty sands that are below the water table. Our analysis indicates that the soils that underlie the proposed
building area have a low risk of liquefying because of the density and gradation of these soils.
Lateral Spreading
Lateral spreading involves lateral displacement of large, surficial blocks of soil as the underlying soil layer
liquefies. Because the buildings will bear on non-liquefiable soils, the potential for lateral spreading is
considered to be low for the project site.
Surface Rupture
The Renton Formation has many small faults with generally low displacement (Mullineaux, 1965). However,
the nearest mapped fault, the Sunbeam fault is approximately ½ mile north of the site. Based on the
distance to this known fault zone, and lack of other known fault zones near the site, it is our opinion that
there is a low to moderate risk of surface rupture at the site.
Other Seismic Hazards
Due to the location of the site and the site’s topography, the risk of adverse impacts resulting from
seismically induced slope instability and differential settlement is considered to be low.
2012 IBC Seismic Design Information
The following 2012 IBC parameters for site class, short period spectral response acceleration (SS),
1-second period spectral response acceleration (S1) and seismic coefficients (FA and FV) are appropriate
for the project site.
TABLE 1. 2012 IBC SEISMIC DESIGN PARAMETERS
2012 IBC Parameter Recommended Value
Site Class C
Short Period Spectral Response Acceleration, SS (percent g) 140.7
1-Second Period Spectral Response Acceleration, S1 (percent g) 52.4
Seismic Coefficient, FA 1.0
Seismic Coefficient, FV 1.3
September 16, 2016 | Page 4 File No. 2202-024-00
Excavations
We understand that the ground floor of the planned building will be at or partially below grade and that the
excavations may extend up to 4 feet below site grades for foundation installation. Temporary cut slopes
may be used for shallow excavations or where there is sufficient space to complete cut slopes. The following
sections provide geotechnical design and construction recommendations for temporary cut slopes.
Excavation Considerations
The site soils may be excavated with conventional excavation equipment, such as trackhoes or dozers.
It may be necessary to rip the glacially consolidated soils locally to facilitate excavation. The contractor
should be prepared for occasional cobbles and boulders in the site soils. Likewise, the surficial fill may
contain foundation elements and/or utilities from previous site development, debris, rubble and/or cobbles
and boulders. We recommend that procedures be identified in the project specifications for measurement
and payment of work associated with obstructions.
Temporary Cut Slopes
Temporary slopes may be used around the site where space allows. We recommend that temporary slopes
constructed in the fill be inclined at 1½H:1V (horizontal to vertical) and that temporary slopes in the glacially
consolidated soils be inclined at 1H:1V. Flatter slopes may be necessary if seepage is present on the face
of the cut slopes or if localized sloughing occurs. For open cuts at the site, we recommend that:
■ no traffic, construction equipment, stockpiles or building supplies be allowed at the top of the cut slopes
within a distance of at least 5 feet from the top of the cut;
■ exposed soil along the slope be protected from surface erosion by using waterproof tarps or plastic
sheeting;
■ construction activities be scheduled so that the length of time the temporary cut is left open is reduced
to the extent practicable;
■ erosion control measures be implemented as appropriate such that runoff from the site is reduced to
the extent practicable;
■ surface water be diverted away from the slope; and
■ the general condition of the slopes be observed periodically by the geotechnical engineer to confirm
adequate stability.
Because the contractor has control of the construction operations, the contractor should be made
responsible for the stability of cut slopes, as well as the safety of the excavations. Temporary slopes must
conform to applicable local, state and federal safety regulations.
Shallow Foundations
Subgrade soils at foundation elevation level for the project will be dependent on the depth of excavation
and the finish floor elevation. The soils at the anticipated foundation elevation vary across the site and may
consist of existing fill or glacially consolidated soils, as such, the bearing capacity and subgrade preparation
will vary. Where foundations bear on competent glacially consolidated soils a high allowable bearing
capacity value can be used. Where fill is present at foundation subgrade elevation, a lower allowable
bearing capacity should be used.
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Once the lowest finish floor elevations have been established for the project, the type/location of
foundation elements should be reviewed by GeoEngineers with the project team. Additional explorations
can be completed to reduce uncertainty with regards to extent of overexcavation. More detail regarding
recommended subgrade preparation and allowable bearing pressures for shallow foundations are
presented below.
Allowable Bearing Pressure
We recommend using an allowable bearing pressure of 10 ksf for mat foundations and isolated spread
footing foundations bearing on the dense to very dense/hard glacially consolidated soils. For foundations
bearing on properly compacted structural fill extended down to dense to very dense/hard glacially
consolidated soils, an allowable bearing pressure of 6 ksf may be used. The estimated depth to the dense
to very dense/hard glacially consolidated soils are summarized in Table 3.
TABLE 2. ESTIMATED DEPTH TO DENSE TO VERY DENSE/HARD GLACIALLY CONSOLIDATED SOILS FOR
FOUNDATION SUPPORT
Exploration Number
Approximate Depth to Competent Glacially Consolidated Soils1
(feet)
GEI-8 1
GEI-9 3
GEI-10 10
GEI-11 2
Notes:
1Depth below existing ground surface
Where foundations are planned to bear on existing fill or highly weathered glacial soils (elevations higher
than shown in Table 2), we recommend a minimum of 2 feet be overexcavated below the foundation
elevation and replaced with compacted structural fill. Existing fill or highly weathered glacial soils will still
remain for this condition; therefore, we recommend an allowable bearing pressure of 3 ksf be used.
The zone of structural fill below the foundation should extend beyond the faces of the footing a distance at
least equal to the thickness of the structural fill. The zone of structural fill should be compacted to at least
95 percent of the MDD in general accordance with ASTM D 1557. If loose existing fill is encountered, further
overexcavation may be necessary.
The allowable soil bearing pressures provided above apply to the total of dead and long-term live loads and
may be increased by up to one-third for wind or seismic loads. The allowable soil bearing pressures are
net values.
We recommend that conventional shallow foundations be a minimum of 36 inches wide and continuous
wall footings be a minimum of 16 inches wide. Exterior footings should be founded a minimum of 18 inches
below the lowest adjacent grade. Interior footings should be founded a minimum of 12 inches below top
of slab.
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Settlement
Provided that all loose soil is removed and that the subgrade is prepared as recommended under
“Construction Considerations” below, we estimate that the total settlement of shallow foundations will be
about 1 inch or less. The settlements will occur rapidly, essentially as loads are applied. Differential
settlements between footings could be half of the total settlement. Note that smaller settlements will result
from lower applied loads.
Lateral Resistance
Lateral foundation loads may be resisted by passive resistance on the sides of footings and by friction on
the base of the shallow foundations. For shallow foundations supported on native soils or structural fill, the
allowable frictional resistance may be computed using a coefficient of friction of 0.4 applied to vertical
dead-load forces.
The allowable passive resistance may be computed using an equivalent fluid density of 390 pounds per
cubic foot (pcf) (triangular distribution). This value is appropriate for foundation elements that are poured
directly against undisturbed glacial till or surrounded by structural fill. The allowable passive resistance for
structural fill assumes that the structural fill extends out from the face of the foundation element for a
distance of at least equal to 2½ times the height of the element and is compacted to at least 95 percent
of the maximum dry density (MDD) in accordance with ASTM D-1557.
The above coefficient of friction and passive equivalent fluid density values incorporate a factor of safety
of about 1.5.
Construction Considerations
We recommend that the condition of all subgrade areas be observed by GeoEngineers to evaluate whether
the work is completed in accordance with our recommendations and whether the subsurface conditions
are as anticipated.
If foundation construction is completed during periods of wet weather, foundation subgrades are
recommended to be protected with a rat slab consisting of 2 to 4 inches of lean or structural concrete.
If soft areas are present at the footing subgrade elevation, the soft areas should be removed and replaced
with lean concrete or structural fill at the direction of GeoEngineers.
We recommend that the contractor consider leaving the subgrade for the foundations as much as 6 to
12 inches high, depending on soil and weather conditions, until excavation to final subgrade is required for
foundation reinforcement. Leaving subgrade high will help reduce damage to the subgrade resulting from
construction traffic for other activities.
Slab-on-Grade Floors
Subgrade Preparation
The exposed subgrade should be evaluated after site grading is complete. Proof-rolling with heavy,
rubber-tired construction equipment should be used for this purpose during dry weather and if access for
this equipment is practical. Probing should be used to evaluate the subgrade during periods of wet weather
or if access is not feasible for construction equipment. The exposed soil should be firm and unyielding, and
September 16, 2016 | Page 7 File No. 2202-024-00
without significant groundwater. Disturbed areas should be recompacted if possible or removed and
replaced with compacted structural fill.
The site should be rough graded to approximately 1 foot above slab subgrade elevation prior to foundation
construction in order to protect the slab subgrade soils from deterioration from wet weather or construction
traffic. After the foundations have been constructed, the remaining soils can be removed to final subgrade
elevation followed by immediate placement of the capillary break material.
In areas were existing fill is present below buildings, the existing soil may be left in place below the slab
provided the slab is founded on at least 1 foot of structural fill compacted to 95 percent of the MDD in
accordance with ASTM D1557. The upper foot of existing fill should also be recompacted to a firm condition
prior to placement of the 1-foot-thick layer of structural fill.
Design Parameters
Conventional slabs may be supported on-grade, provided the subgrade soils are prepared as recommended
in the “Subgrade Preparation” section above. For slabs designed as a beam on an elastic foundation, a
modulus of subgrade reaction of 150 pounds per cubic inch (pci) may be used for slabs supported on
glacial till. For slabs supported on a 1-foot layer of structural fill overlying existing fill soils, we recommend
a modulus of subgrade reaction of 100 pci.
We recommend that the slab-on-grade floors be underlain by a 6-inch-thick capillary break consisting of
1½-inch minus clean crushed gravel with negligible sand or silt meeting the requirements Washington State
Department of Transportation (WSDOT) Standard Specification 9-03.1(4)C, grading No. 57 or Mineral
Aggregate Type 22 (¾-inch crushed gravel), City of Seattle Standard Specification 9-03.16.
Provided that loose soil is removed and the subgrade is prepared as recommended, we estimate that
slabs-on-grade will not settle appreciably.
Below-Slab Drainage
We expect the static groundwater level to be located well below the slab-on-grade level for the proposed
building; however perched groundwater may be present above the slab subgrade elevation. We recommend
installing an underslab drainage system to remove water from below the slabs-on-grade. The underslab
drainage system should include an interior perimeter drain and one or more longitudinal drains with
transverse pipes placed at a nominal spacing of 20 feet. The location of the longitudinal drain(s) will depend
on the foundation and below-grade structure design and may need to be modified to two or more transverse
drains or drains located behind interior cast-in-place walls. The civil engineer should develop a conceptual
foundation drainage plan for GeoEngineers to review.
The drains should consist of perforated Schedule 40 polyvinyl chloride (PVC) pipes with a minimum
diameter of 4 inches placed in a trench at least 12 inches deep. The top of the underslab drainage system
trenches should coincide with the base of the capillary break layer. The underslab drainage system pipes
should have adequate slope to allow positive drainage to the sump/gravity drain.
The drainage pipe should be perforated. Perforated pipe should have two rows of ½-inch holes spaced
120 degrees apart and at 4 inches on center. The underslab drainage system trenches should be
backfilled with Mineral Aggregate Type 22 or Type 5 (1-inch washed gravel), City of Seattle Standard
September 16, 2016 | Page 8 File No. 2202-024-00
Specification 9-03.16, or gravel backfill for drains in conformance with WSDOT Standard Specification
9-03.12(4). The material should be wrapped with a geotextile filter fabric meeting the requirements
of construction geotextile for underground drainage, Washington State Department of Transportation
(WSDOT) Standard Specification 9-33. The underslab drainage system pipes should be connected to a
header pipe and routed to a sump or gravity drain. Appropriate cleanouts for drainpipe maintenance should
be installed. A larger diameter pipe will allow for easier maintenance of drainage systems. The flow rate for
the planned excavation in the below-slab drainage and below-grade wall drainage systems is anticipated
to be on the order of 5 to 10 gpm.
If no special waterproofing measures are taken, leaks and/or seepage may occur in localized areas of the
below-grade portion of the building, even if the recommended wall drainage and below-slab drainage
provisions are constructed. If leaks or seepage is undesirable, below-grade waterproofing should be
specified. A vapor barrier should be used below slab-on-grade floors located in occupied portions of the
building. Specification of the vapor barrier requires consideration of the performance expectations of the
occupied space, the type of flooring planned and other factors, and is typically completed by other members
of the project team.
If partial below-grade waterproofing is specified (for instance, for elevator pits), the waterproofing should
extend to at least the elevation of the lowest finished floor so that the waterproofing will be located above
the elevation where foundation drainage is provided.
Below-Grade Walls
Other Cast-in-Place Walls
Conventional cast-in-place walls may be necessary for small retaining structures located on-site or where
temporary open cuts are used for excavation support. The lateral soil pressures acting on conventional
cast-in-place subsurface walls will depend on the nature, density and configuration of the soil behind the
wall and the amount of lateral wall movement that can occur as backfill is placed.
For walls that are free to yield at the top at least 0.1 percent of the height of the wall, soil pressures will be
less than if movement is limited by such factors as wall stiffness or bracing. Assuming that the walls are
backfilled and drainage is provided as outlined in the following paragraphs, we recommend that yielding
walls supporting horizontal backfill be designed using an equivalent fluid density of 35 pcf (triangular
distribution), while non-yielding walls supporting horizontal backfill be designed using an equivalent fluid
density of 55 pcf (triangular distribution). For seismic loading conditions, a rectangular earth pressure equal
to 14H pounds per square foot (psf) (where H is the height of the wall in feet) should be added to the
active/at-rest pressures. A traffic surcharge pressure of 70 psf should also be included in the design, as
appropriate. Other surcharge loading should be applied as appropriate using the recommendations
provided in Figure 5.
We recommend that below-grade wall or other retaining wall foundations be designed using the foundation
recommendations provided above under “Shallow Foundations.” For retaining walls independent of
building structures (grade-transition walls), the retaining wall footings may be supported on 2 feet of
structural fill placed over the existing fill soils. The upper foot of existing fill should also be recompacted to
a firm condition prior to placement of the 2-foot-thick layer of structural fill. An allowable bearing pressure
of 3 ksf may be used for this foundation support condition.
September 16, 2016 | Page 9 File No. 2202-024-00
Lateral resistance for conventional cast-in-place walls can be provided by frictional resistance along the
base of the wall and passive resistance in front of the wall. For walls founded on native soils or structural
fill, the allowable frictional resistance may be computed using a coefficient of friction of 0.4 applied to
vertical dead-load forces. The allowable passive resistance may be computed using an equivalent fluid
densities of 390 pcf (triangular distribution). The allowable passive resistance for structural fill assumes
that the structural fill extends out from the face of the foundation element for a distance of at least equal
to 2½ times the height of the element and is compacted to at least 95 percent of the MDD in accordance
with ASTM D-1557. The above coefficient of friction and passive equivalent fluid density values incorporate
a factor of safety of about 1.5.
The above soil pressures assume that wall drains will be installed to prevent the buildup of hydrostatic
pressure behind the walls, as discussed below.
Drainage
Positive drainage should be provided behind cast-in-place retaining walls by placing a minimum 2-foot-wide
zone of Mineral Aggregate Type 17 (bank run gravel), City of Seattle Standard Specification 9-03.16, with
the exception that the percent passing the U.S. No. 200 sieve is to be less than 3 percent. Alternatively, the
2-foot-wide zone of material may consist of gravel backfill for walls in conformance with WSDOT Standard
Specification 9-03.12(2).
A perforated drainpipe should be placed near the base of the retaining wall to provide drainage. The
drainpipe should be surrounded by a minimum of 6 inches of Mineral Aggregate Type 22 (¾-inch crushed
gravel) or Type 5 (1-inch washed gravel), City of Seattle Standard Specification 9-03.16, or gravel backfill
for drains in conformance with WSDOT Standard Specification 9-03.12(4). The material should be wrapped
with a geotextile filter fabric meeting the requirements of construction geotextile for underground drainage,
WSDOT Standard Specification 9-33. The wall drainpipe should be connected to a header pipe and
routed to a sump or gravity drain. Appropriate cleanouts for drainpipe maintenance should be installed.
A larger-diameter pipe will allow for easier maintenance of drainage systems.
Earthwork
Stripping, Clearing and Grubbing
We recommend that all new pavement and structure areas be stripped of existing pavements, concrete
and vegetation in landscape areas. The asphalt pavement thickness in the project area is generally
between 1½ and 3 inches of asphalt concrete as encountered in the borings. The stripped organic soil from
the landscape areas may be stockpiled for later use as topsoil for landscaping purposes.
Erosion and Sedimentation Control
Potential sources or causes of erosion and sedimentation depend upon construction methods, slope length
and gradient, amount of soil exposed and/or disturbed, soil type, construction sequencing, and weather.
The project’s impact on erosion-prone areas can be reduced by implementing an erosion and sedimentation
control plan. The plan should be designed in accordance with applicable City and/or county standards.
The plan should incorporate basic planning principles including:
■ scheduling grading and construction to reduce soil exposure;
■ retaining existing vegetation whenever feasible;
September 16, 2016 | Page 10 File No. 2202-024-00
■ revegetating or mulching denuded areas;
■ directing runoff away from denuded areas;
■ minimizing the length and steepness of slopes with exposed soils;
■ decreasing runoff velocities;
■ confining sediment to the project site;
■ inspecting and maintaining control measures frequently;
■ covering soil stockpiles; and
■ implementing proper erosion control best management practices (BMPs).
Temporary erosion protection should be used and maintained in areas with exposed or disturbed soils to
help reduce the potential for erosion and reduce transport of sediment to adjacent areas. Temporary
erosion protection should include the construction of a silt fence around the perimeter of the work area
prior to the commencement of grading activities. Permanent erosion protection should be provided by
reestablishing vegetation using hydroseeding and/or landscape planting.
Until the permanent erosion protection is established and the site is stabilized, site monitoring should be
performed by qualified personnel to evaluate the effectiveness of the erosion control measures and repair
and/or modify them as appropriate. Provisions for modifications to the erosion control system based on
monitoring observations should be included in the erosion and sedimentation control plan.
Subgrade Preparation
The exposed subgrade in structure and hardscape areas should be evaluated after site excavation is
complete. Disturbed areas below slabs and foundations should be recompacted if the subgrade
soil consists of granular material. If the subgrade soils consist of disturbed soils, it will likely be necessary
to remove and replace the disturbed soil with structural fill unless the soil can be adequately moisture-
conditioned and compacted.
Structural Fill
Fill placed to support structures, placed behind retaining structures, and placed below pavements and
sidewalks will need to be specified as structural fill as described below:
■ Structural fill placed within utility trenches and below pavement and sidewalk areas and
below foundations should meet the requirements of Mineral Aggregate Type 17 (bank run gravel), City
of Seattle Standard Specification 9-03.16, or WSDOT common borrow as described in Section
9-03.14(3). Common borrow is only suitable for use during dry weather. If fill is placed during wet
weather, WSDOT gravel borrow should be used, as described in Section 9-03.14(1).
■ Structural fill placed as capillary break material should meet the requirements of Type 22 (¾-inch
crushed gravel), City of Seattle Standard Specification 9-03.16, or Section 9-03.1(4)C, grading No. 57
of the WSDOT Standard Specifications (1½-inch minus crushed gravel).
■ Structural fill placed behind retaining walls should meet the requirements of Mineral Aggregate Type 17
(bank run gravel), City of Seattle Standard Specification 9-03.16, or WSDOT gravel backfill for walls
Section 9-03.12(2).
September 16, 2016 | Page 11 File No. 2202-024-00
■ Structural fill placed around perimeter footing drains, underslab drains and cast-in-place wall drains
should meet the requirements of Mineral Aggregate Type 5 (1-inch washed gravel) or Type 22 (¾-inch
crushed gravel), City of Seattle Standard Specification 9-03.16, or WSDOT gravel backfill for drains
Section 9-03.12(4).
■ Structural fill placed as crushed surfacing base course below pavements and sidewalks should meet
the requirements of Mineral Aggregate Type 2 (1¼-inch minus crushed rock), City of Seattle Standard
Specification 9-03.16, or Section 9-03.9(3) of the WSDOT Standard Specifications.
On-site Soils
The on-site soils are moisture-sensitive and generally have natural moisture contents higher than the
anticipated optimum moisture content for compaction. As a result, the on-site soils will likely require
moisture conditioning in order to meet the required compaction criteria during dry weather conditions and
will not be suitable for reuse during wet weather. Furthermore, most of the fill soils required for the project
have specific gradation requirements, and the on-site soils do not meet these gradation requirements. If the
contractor wants to use on-site soils for structural fill, GeoEngineers can evaluate the on-site soils for
suitability as structural fill, as required.
Fill Placement and Compaction Criteria
Structural fill should be mechanically compacted to a firm, non-yielding condition. Structural fill should be
placed in loose lifts not exceeding 1 foot in thickness. Each lift should be conditioned to the proper moisture
content and compacted to the specified density before placing subsequent lifts. Structural fill should be
compacted to the following criteria:
■ Structural fill placed in building areas (supporting or adjacent to foundations or slab-on-grade floors)
should be compacted to at least 95 percent of the maximum dry density (MDD) estimated in general
accordance with ASTM D 1557.
■ Structural fill placed within 10 feet of the back of subgrade and retaining walls should be compacted
to between 90 and 92 percent of the MDD. Care should be taken when compacting fill against
subsurface walls to avoid over-compaction and hence overstressing the walls. Structural fill beyond this
10-foot zone should be compacted to at least 95 percent of the MDD.
■ Structural fill in new pavement and roadway areas, including utility trench backfill, should be
compacted to 90 percent of the MDD, except that the upper 2 feet of fill below final subgrade should
be compacted to 95 percent of the MDD.
■ Structural fill placed as crushed rock base course below pavements should be compacted to
95 percent of the MDD.
We recommend that GeoEngineers be present during probing of the exposed subgrade soils in building and
pavement areas, and during placement of structural fill. We will evaluate the adequacy of the subgrade
soils and identify areas needing further work, perform in-place moisture-density tests in the fill to verify
compliance with the compaction specifications, and advise on any modifications to the procedures that
may be appropriate for the prevailing conditions.
September 16, 2016 | Page 12 File No. 2202-024-00
Weather Considerations
The on-site soils contain a sufficient percentage of fines (silt and clay) to be moisture-sensitive. When the
moisture content of these soils is more than a few percent above the optimum moisture content, these
soils become muddy and unstable, and operation of equipment on these soils is difficult. Additionally,
disturbance of near-surface soils should be expected if earthwork is completed during periods of wet
weather. During wet weather, we recommend that:
■ The ground surface in and around the work area should be sloped so that surface water is directed
away from the work area. The ground surface should be graded such that areas of ponded water do
not develop. The contractor should take measures to prevent surface water from collecting in
excavations and trenches. Measures should be implemented to remove surface water from the work
area.
■ Slopes with exposed soils should be covered with plastic sheeting or similar means.
■ The site soils should not be left uncompacted and exposed to moisture. Sealing the surficial soils by
rolling with a smooth-drum roller prior to periods of precipitation will reduce the extent to which these
soils become wet or unstable.
■ Construction traffic should be restricted to specific areas of the site, preferably areas that are surfaced
with materials not susceptible to wet weather disturbance.
■ Construction activities should be scheduled so that the length of time that soils are left exposed to
moisture is reduced to the extent practicable.
Permanent Slopes
We recommend that permanent cut and fill slopes be constructed no steeper than 2H:1V. To achieve
uniform compaction, we recommend that fill slopes be overbuilt slightly (1 to 2 feet) and subsequently cut
back to expose properly compacted fill. We recommend that the finished slope faces be compacted by track
walking with the equipment running perpendicular to the slope contours so that the track grouser marks
help provide an erosion-resistant slope texture.
To reduce erosion, newly constructed slopes should be planted or hydroseeded shortly after completion of
grading. Until the vegetation is established, some sloughing and raveling of the slopes should be expected.
This may require localized repairs and reseeding. Temporary covering, such as clear heavy plastic sheeting,
jute fabric, loose straw, or excelsior or straw/coconut matting, should be used to protect the slopes during
periods of rainfall.
Pavement Design
Subgrade Preparation
We recommend that the subgrade soils in new pavement areas be prepared and evaluated as described
in the “Earthwork” section of this report. We recommend that the subgrade be compacted to at least
95 percent of the MDD per ASTM D 1557 prior to placing pavement section materials. If the subgrade soils
are loose or soft, it may be necessary to excavate the soils and replace them with structural fill. A layer of
suitable woven geotextile fabric may be placed over soft subgrade areas to limit the thickness of structural
fill required to bridge soft, yielding areas. The depth of overexcavation or fabric placement should be
evaluated by GeoEngineers during construction.
September 16, 2016 | Page 13 File No. 2202-024-00
September 16, 2016 | Page 14
File No. 2202-024-00
New Hot-Mix Asphalt Pavement
In light-duty pavement areas (e.g., automobile parking), we recommend a pavement section consisting of
at least a 2-inch thickness of ½-inch HMA (PG 58-22) per WSDOT Sections 5-04 and 9-03, over a 4-inch
thickness of densely compacted crushed rock base course per WSDOT Section 9-03.9(3). In heavy-duty
pavement areas (e.g., truck traffic areas, materials delivery, forklifts) around the building, we recommend
a pavement section consisting of at least a 4-inch thickness of ½-inch HMA (PG 58-22) over a 6-inch
thickness of densely compacted crushed rock base course. The base course should be compacted to at
least 95 percent of the maximum dry density (ASTM D 1557). We recommend that a proof-roll of the
compacted base course be observed by a representative from our firm prior to paving. Soft or yielding areas
observed during proof-rolling may require over-excavation and replacement with compacted structural fill.
The pavement sections recommended above are based on our experience. Thicker asphalt sections may
be needed based on the actual subgrade conditions, traffic data and intended use.
Infiltration
In the northern portion of the proposed MOB building footprint, native glacially consolidated soils and
sandstone bedrock were encountered and consisted of dense to very dense silty sand and gravel with
varying silt content. In the southern portion, mainly near GEI-10, fill overlies the glacially consolidated soils.
The fill consists of loose to medium dense silty sand. The fill contains a significant portion of fines. The
glacially consolidated soils are compact and contain a significant percentage of fines, which limits the
infiltration capacity. Additionally, the cemented nature of the glacial till and sandstone bedrock typically
does not allow for infiltration.
Grain size analyses were completed on two soil samples, GEI-8 at a depth of 2.5 feet below ground
surface (bgs) and GEI-10 at 5 feet bgs. GeoEngineers determined preliminary long-term design infiltration
rates in general accordance with the 2012 Stormwater Management Manual of Western Washington
(SMMWW) using the simplified Soil Grain Size Analysis Method. The method consists of correlations based
on sieve analysis results, as discussed in Section 3.3.6 of the SMMWW manual. Based on this analysis, we
estimate a preliminary long-term design infiltration rate of 0.5 inches per hour in the southern portion of
the site for depths of 2 to 5 feet bgs where fill is present. Infiltration is not considered feasible in the glacial
soils encountered in the northern portion of the site and below a depth of about 2 to 5 feet in the southern
portion of the site, due to the presence of glacial soils below this depth.
It should be noted that the City of Renton has adopted and amended sections of the 2009 King County
Surface Water Design Manual and it specifies that the measured infiltration rate be measured in
accordance with the EPA Falling Head Method or the Double Ring Infiltrometer Method. However, the City
of Renton amendments states “For some soils, an infiltration rate of less than 9 inches per hour may be
assumed based on soil texture determination rather than a rate measurement.” Based on this exception,
the value of 0.5 inches per hour can be used for design, unless a measured value using one of the methods
referenced above is completed in the field.
It is our opinion that the on-site soils provide low infiltration capacity and extensive stormwater infiltration
facilities are not recommended for the site.
Recommended Additional Geotechnical Services
GeoEngineers should be retained to review the project plans and specifications when complete to confirm
that our design recommendations have been implemented as intended. Any changes in design, especially
the incorporation of elements that deepen the required depth of excavation, will likely go below the water
table and could require additional temporary construction dewatering measures.
During construction, GeoEngineers should evaluate the suitability of the foundation subgrades, observe
installation of subsurface drainage measures, evaluate structural backfill, observe the condition of
temporary cut slopes, and provide a summary letter of our construction observation services. The purposes
of GeoEngineers construction phase services are to confirm that the subsurface conditions are consistent
with those observed in the explorations and other reasons described in Appendix D, Report Limitations and
Guidelines for Use.
LIMITATIONS
We have prepared this report for the exclusive use of Valley Medical Center and their authorized agents for
the VMC FY 2017 Medical Office Building Project in Renton, Washington.
Within the limitations of scope, schedule and budget, our services have been executed in accordance with
generally accepted practices in the field of geotechnical engineering in this area at the time this report was
prepared. No warranty or other conditions, express or implied, should be understood.
Any electronic form, facsimile or hard copy of the original document (email, text, table and/or figure), if
provided, and any attachments are only a copy of the original document. The original document is stored
by GeoEngineers, Inc. and will serve as the official document of record.
Please refer to Appendix D titled “Report Limitations and Guidelines for Use” for additional information
pertaining to use of this report.
REFERENCES
City of Renton Public Works Department, 2010 “Amendments to the 2009 King County Surface Water
Design Manual.”
City of Seattle, 2014, “Standard Specifications for Road, Bridge and Municipal Construction.”
International Code Council, 2012, “International Building Code.”
King County Department of Natural Resources and Parks, 2009 “Surface Water Design Manual.”
Mullineaux D.R., 1965 “Geologic Map of the Renton Quadrangle, King County, Washington.” USGS.
U.S. Department of Transportation, Federal Highways Administration, 1999, “Geotechnical Engineering
Circular No. 4, Ground Anchors and Anchored Systems,” FHWA Report No. FHWA-IF-99-015.
September 16, 2016 | Page 15
File No. 2202-024-00
U.S. Geological Survey – National Seismic hazard Mapping project Software, “Earthquake Ground Motion
Parameters, Version 5.0.9a,” 2002 data, 2009.
Washington State Department of Ecology, “Stormwater Management Manual for Western Washington,”
2012.
Washington State Department of Transportation, 2014, “Standard Specifications for Road, Bridge and
Municipal Construction.”
September 16, 2016 | Page 16 File No. 2202-024-00
FIGURES
!
µ
Vicinity Map
Figure 1
Valley Medical CenterRenton, Washington
2,000 2,0000
Feet
Data Sources: Open Street Map, 2016.
Notes:1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication.3. It is unlawful to copy or reproduce all or any part thereof, whether for personal use or resale, without permission.
Transverse Mercator, Zone 10 N North, North American Datum 1983North arrow oriented to grid northPath: P:\2\2202024\GIS\220202400_F1_VicinityMap.mxdMap Revised: 4/19/2016 glohrmeyerSite
Talbot Road SouthProposed Parking Garage
Proposed MOB
23
22
21 25 24
28
27
26
B-2
B-1
B-2
B-4
B-6
B-7
B-5
B-3
GEI-3
GEI-4
GEI-2
GEI-6
GEI-7
GEI-8
GEI-9
GEI-10 GEI-11
GEI-5
HA-2
HA-1
B-2
B-3
B-4
B-1
1
GEI-1
Main
Hospital
Building
Talbot
Professional
Building
Psychiatry Wing
Northwest Pavilion
Building
Parking
Garage
Medical Arts Center
Olympic
Building
Valley Professional
Center North Building
60
65
70
75
80
85
9090
85807550407555100
95W E
N
S
Feet
0100 100
P:\2\2202024\CAD\00\Geotech\2202024-00_F02_Site Plan.dwg TAB:F2 Date Exported: 05/06/16 - 12:39 by cstickelValley Medical Center
Renton, Washington
Site Plan
Figure 2
Projection: NAD83 Washington State Planes, North Zone, US Foot.
Notes:
1.The locations of all features shown are approximate.
2.This drawing is for information purposes. It is intended to assist in showing
features discussed in an attached document. GeoEngineers, Inc. cannot
guarantee the accuracy and content of electronic files. The master file is stored
by GeoEngineers, Inc. and will serve as the official record of this communication.
Data Source: Base aerial photo for Microsoft bing map server.
Legend
Boring by GeoEngineers, 2016
Boring by Terra Associates, 1989
Boring by Converse Consultants NW, 1987
Boring by Converse Consultants NW, 1989
Test Pit by Converse Consultants NW, 1987
B-1
1
B-2
GEI-1
21
Proposed Building
HA-1
B-1 Boring by GeoEngineers, 2001
Hand Auger by GeoEngineers, 2001
APPENDICES
APPENDIX A Field Explorations
APPENDIX A
FIELD EXPLORATIONS
Subsurface conditions were explored at the site by drilling four borings (GEI-8 through GEI-11). The borings
were completed to depths of approximately 21 to 26½ feet below existing site grades. The borings were
completed by Geologic Drill, Inc. on April 5, 2016.
The locations of the explorations were surveyed by Bush Roed & Hitchings, Inc. as part of the general project
survey. The exploration locations are shown on the Site Plan, Figure 2.
Borings
The borings were completed using track-mounted, continuous-flight, hollow-stem auger drilling equipment,
owned and operated by Geologic Drill, Inc. of Spokane, Washington. The borings were continuously
monitored by a geotechnical engineer or geologist from our firm who examined and classified the soils
encountered, obtained representative soil samples, observed groundwater conditions and prepared a
detailed log of each exploration.
The soils encountered in the borings were generally sampled at 2½- and 5-foot vertical intervals with a
2-inch outside diameter split-barrel standard penetration test (SPT) sampler. The disturbed samples were
obtained by driving the sampler 18 inches into the soil with a 140-pound automatic hammer free-falling
30 inches. The number of blows required for each 6 inches of penetration was recorded. The blow count
("N-value") of the soil was calculated as the number of blows required for the final 12 inches of penetration.
This resistance, or N-value, provides a measure of the relative density of granular soils and the relative
consistency of cohesive soils. Where very dense soil conditions precluded driving the full 18 inches, the
penetration resistance for the partial penetration was entered on the logs. The blow counts are shown on
the boring logs at the respective sample depths.
Soils encountered in the borings were visually classified in general accordance with the classification
system described in Figure A-1. A key to the boring log symbols is also presented in Figure A-1. The logs of
the borings are presented in Figures A-2 through A-5. The boring logs are based on our interpretation of the
field and laboratory data and indicate the various types of soils and groundwater conditions encountered.
The logs also indicate the depths at which these soils or their characteristics change, although the change
may actually be gradual. If the change occurred between samples, it was interpreted. The densities noted
on the boring logs are based on the blow count data obtained in the borings and judgment based on the
conditions encountered.
Observations of groundwater conditions were made during drilling. The groundwater conditions
encountered during drilling are presented on the boring logs. Groundwater conditions observed during
drilling represent a short-term condition and may or may not be representative of the long-term groundwater
conditions at the site. Groundwater conditions observed during drilling should be considered approximate.
September 16, 2016 | Page A-1 File No. 2202-024-00
AC
Cement ConcreteCC
Asphalt Concrete
No Visible SheenSlight Sheen
Moderate SheenHeavy SheenNot Tested
NSSS
MSHSNT
ADDITIONAL MATERIAL SYMBOLS
Measured groundwater level in
exploration, well, or piezometer
Measured free product in well or
piezometer
Graphic Log Contact
Groundwater Contact
Material Description Contact
Laboratory / Field Tests
Sheen Classification
Sampler Symbol Descriptions
NOTE: The reader must refer to the discussion in the report text and the logs of explorations for a proper understanding of subsurfaceconditions. Descriptions on the logs apply only at the specific exploration locations and at the time the explorations were made; they are
not warranted to be representative of subsurface conditions at other locations or times.
GRAPH
Topsoil/
Forest Duff/Sod
Crushed Rock/Quarry Spalls
FIGURE A-1
2.4-inch I.D. split barrel
SYMBOLS TYPICAL
KEY TO EXPLORATION LOGS
CR
DESCRIPTIONSLETTER
TS
GC
PT
OH
CH
MH
OL
GM
GP
GW
DESCRIPTIONS
TYPICAL
LETTER
(APPRECIABLE AMOUNT
OF FINES)
MAJOR DIVISIONS
POORLY-GRADED SANDS,GRAVELLY SAND
PEAT, HUMUS, SWAMP SOILSWITH HIGH ORGANICCONTENTS
CLEAN SANDS
GRAVELS WITH
FINES
CLEAN
GRAVELS
HIGHLY ORGANIC SOILS
SILTS
AND
CLAYS
SILTS
AND
CLAYS
SANDANDSANDY
SOILS
GRAVEL
AND
GRAVELLY
SOILS
(LITTLE OR NO FINES)
FINEGRAINED
SOILS
COARSE
GRAINED
SOILS
SW
MORE THAN 50%OF COARSEFRACTIONRETAINED ON NO.4 SIEVE
CL
WELL-GRADED SANDS,GRAVELLY SANDS
SILTY GRAVELS, GRAVEL - SAND- SILT MIXTURES
LIQUID LIMITGREATER THAN 50
SILTY SANDS, SAND - SILTMIXTURES
(APPRECIABLE AMOUNTOF FINES)
SOIL CLASSIFICATION CHART
LIQUID LIMITLESS THAN 50
SANDS WITHFINES
SP(LITTLE OR NO FINES)
ML
SC
SM
NOTE: Multiple symbols are used to indicate borderline or dual soil classifications
MORE THAN 50%OF COARSEFRACTIONPASSING NO. 4SIEVE
CLAYEY GRAVELS, GRAVEL -SAND - CLAY MIXTURES
CLAYEY SANDS, SAND - CLAYMIXTURES
INORGANIC SILTS, ROCKFLOUR, CLAYEY SILTS WITHSLIGHT PLASTICITY
ORGANIC SILTS AND ORGANICSILTY CLAYS OF LOWPLASTICITY
INORGANIC SILTS, MICACEOUSOR DIATOMACEOUS SILTYSOILS
ORGANIC CLAYS AND SILTS OFMEDIUM TO HIGH PLASTICITY
INORGANIC CLAYS OF HIGHPLASTICITY
MORE THAN 50%PASSING NO. 200SIEVE
MORE THAN 50%RETAINED ON NO.200 SIEVE
WELL-GRADED GRAVELS,GRAVEL - SAND MIXTURES
POORLY-GRADED GRAVELS,GRAVEL - SAND MIXTURES
INORGANIC CLAYS OF LOW TOMEDIUM PLASTICITY, GRAVELLYCLAYS, SANDY CLAYS, SILTYCLAYS, LEAN CLAYS
GRAPH
SYMBOLS
Standard Penetration Test (SPT)
Shelby tube
Piston
Direct-Push
Bulk or grab
Continuous Coring
Distinct contact between soil strata
Approximate contact between soil
strata
Contact between geologic units
Contact between soil of the samegeologic unit
%F%G
ALCA
CPCSDS
HAMCMD
OCPMPI
PPPPM
SATXUC
VS
Percent fines
Percent gravelAtterberg limitsChemical analysis
Laboratory compaction testConsolidation testDirect shear
Hydrometer analysisMoisture content
Moisture content and dry densityOrganic contentPermeability or hydraulic conductivity
Plasticity indexPocket penetrometerParts per million
Sieve analysisTriaxial compressionUnconfined compression
Vane shear
Blowcount is recorded for driven samplers as the numberof blows required to advance sampler 12 inches (or
distance noted). See exploration log for hammer weightand drop.
A "P" indicates sampler pushed using the weight of thedrill rig.
A "WOH" indicates sampler pushed using the weight ofthe hammer.
Rev. 02/16
1SA
2%F
3
4
5
16
12
15
6
18
56
50/6"
73
50/5"
65
3 inches asphalt concrete pavement
3 inches base course
Gray silty fine to medium sand with gravel (verydense, moist) (glacial till)
Becomes with occasional gravel
AC
GP
SM
Light oxidation staining31
21
8
5
TotalDepth (ft)
HammerData
SystemDatum
Start End
Checked By
Logged By
DTMDrilled
Notes:
SJB
Surface Elevation (ft)
Vertical Datum
Driller
Groundwater Depth toWater (ft)Date Measured Elevation (ft)
Easting (X)Northing (Y)
Diedrich D50 Track Rig
Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger21.5
Autohammer140 (lbs) / 30 (in) Drop
DrillingEquipment
4/5/20164/5/2016
Not encountered
82.72
NAVD88
1298995.48
165009.65
WA State Plane,North
NAD83 (feet)
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)0
5
10
15
20 IntervalElevation (feet)80757065Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-8
Valley Medical Center - Medical Office Building Project
Renton, Washington
2202-024-00 Task 200
Project:
Project Location:
Project Number:Figure A-2
Sheet 1 of 1Redmond: Date:5/6/16 Path:W:\PROJECTS\2\2202024\GINT\0220202400.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS
FinesContent (%)MoistureContent (%)
1
2%F
3
4
5MC
12
11.5
15
10
18
35
50/5.5"
90/11"
65
65
1.5 inches asphalt concrete pavement
5.5 inches base course
Brown to gray silty fine to coarse sand withgravel and occasional coal fragments(dense, moist) (weathered glacial till)
Gray sandy silt with occasional gravel (hard,moist) (glacial till)
Gray silty fine to medium sand with gravel (verydense, moist)
Large boulder obstruction
Becomes wet
AC
GP
SM
ML
SM
Light oxidation staining
Drilling on rock at 12 feet bgs
Moved over 5 feet to complete boring
Perched water
569
12
TotalDepth (ft)
HammerData
SystemDatum
Start End
Checked By
Logged By
DTMDrilled
Notes:
SJB
Surface Elevation (ft)
Vertical Datum
Driller
Groundwater Depth toWater (ft)Date Measured Elevation (ft)
Easting (X)Northing (Y)
Diedrich D50 Track Rig
Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger25.8
Autohammer140 (lbs) / 30 (in) Drop
DrillingEquipment
4/5/20164/5/2016
See remarks
91.83
NAVD88
1299121.94
165017.35
WA State Plane,North
NAD83 (feet)
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)0
5
10
15
20 IntervalElevation (feet)9085807570Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-9
Valley Medical Center - Medical Office Building Project
Renton, Washington
2202-024-00 Task 200
Project:
Project Location:
Project Number:Figure A-3
Sheet 1 of 2Redmond: Date:5/6/16 Path:W:\PROJECTS\2\2202024\GINT\0220202400.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS
FinesContent (%)MoistureContent (%)
6950/3"
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)25 IntervalElevation (feet)Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-9 (continued)
Valley Medical Center - Medical Office Building Project
Renton, Washington
2202-024-00 Task 200
Project:
Project Location:
Project Number:Figure A-3
Sheet 2 of 2Redmond: Date:5/6/16 Path:W:\PROJECTS\2\2202024\GINT\0220202400.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS
FinesContent (%)MoistureContent (%)
1
2SA
3
4
5
6
18
18
18
18
18
11
10
11
29
48
82
50/5"
1.5 inches asphalt concrete pavement
4 inches base course
Brown/orange silty fine to coarse sand withgravel (loose to medium dense, moist) (fill)
Gray silty fine sand with occasional gravel(medium dense, moist)
Becomes wet
Gray silty fine to medium sand with occasional
gravel (dense, moist) (glacial till)
Becomes very dense
Gray silty fine to medium sand (very dense,moist) (Renton Formation Sandstone)
AC
GP
SM
SM
SM
SM
Oxidation staining
Perched water
4117
TotalDepth (ft)
HammerData
SystemDatum
Start End
Checked By
Logged By
DTMDrilled
Notes:
SJB
Surface Elevation (ft)
Vertical Datum
Driller
Groundwater Depth toWater (ft)Date Measured Elevation (ft)
Easting (X)Northing (Y)
Diedrich D50 Track Rig
Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger20.9
Autohammer140 (lbs) / 30 (in) Drop
DrillingEquipment
4/5/20164/5/2016
See remarks
86.23
NAVD88
1298928.15
164820.19
WA State Plane,North
NAD83 (feet)
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)0
5
10
15
20 IntervalElevation (feet)85807570Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-10
Valley Medical Center - Medical Office Building Project
Renton, Washington
2202-024-00 Task 200
Project:
Project Location:
Project Number:Figure A-4
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FinesContent (%)MoistureContent (%)
1
2%F
3
4
5
18
15
7
10
8
52
50
50/1"*
50/4"
50/6"
1.5 inches asphalt concrete pavement
Brown silty fine to medium sand with gravel(medium dense, moist) (fill)
Brown to gray silty fine to medium sand withoccasional gravel and coal fragments (verydense, moist) (weathered glacial till)
Gray silty fine to medium sand with gravel (verydense, moist) (glacial till)
Increasing gravel
AC
SM
SM
SM
No base course
Oxidation staining
*Sampler bouncing on rock, blowcountoverstated
3812
TotalDepth (ft)
HammerData
SystemDatum
Start End
Checked By
Logged By
DTMDrilled
Notes:
SJB
Surface Elevation (ft)
Vertical Datum
Driller
Groundwater Depth toWater (ft)Date Measured Elevation (ft)
Easting (X)Northing (Y)
Diedrich D50 Track Rig
Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger26.5
Autohammer140 (lbs) / 30 (in) Drop
DrillingEquipment
4/5/20164/5/2016
Not encountered
91.62
NAVD88
1299044.81
164830.36
WA State Plane,North
NAD83 (feet)
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)0
5
10
15
20 IntervalElevation (feet)9085807570Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-11
Valley Medical Center - Medical Office Building Project
Renton, Washington
2202-024-00 Task 200
Project:
Project Location:
Project Number:Figure A-5
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FinesContent (%)MoistureContent (%)
61041
With interbeds of coarse sand and trace gravel
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)25 IntervalElevation (feet)Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-11 (continued)
Valley Medical Center - Medical Office Building Project
Renton, Washington
2202-024-00 Task 200
Project:
Project Location:
Project Number:Figure A-5
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FinesContent (%)MoistureContent (%)
APPENDIX B Laboratory Testing
APPENDIX B
LABORATORY TESTING
Soil samples obtained from the explorations were transported to GeoEngineers’ laboratory and evaluated
to confirm or modify field classifications, as well as to evaluate engineering properties of the soil samples.
Representative samples were selected for laboratory testing to determine the moisture content, percent
fines (material passing the U.S. No. 200 sieve) and sieve analyses. The tests were performed in general
accordance with test methods of ASTM International (ASTM) or other applicable procedures.
Moisture Content
Moisture content tests were completed in general accordance with ASTM D 2216 for representative
samples obtained from the explorations. The results of these tests are presented on the exploration logs in
Appendix A at the depths at which the samples were obtained.
Percent Passing U.S. No. 200 Sieve (%F)
Selected samples were “washed” through the U.S. No. 200 mesh sieve to estimate the relative percentages
of coarse- and fine-grained particles in the soil. The percent passing value represents the percentage by
weight of the sample finer than the U.S. No. 200 sieve. These tests were conducted to verify field
descriptions and to estimate the fines content for analysis purposes. The tests were conducted in
accordance with ASTM D 1140, and the results are shown on the exploration logs in Appendix A at the
respective sample depths.
Sieve Analyses
Sieve analyses were performed on selected samples in general accordance with ASTM D 422. The wet
sieve analysis method was used to determine the percentage of soil greater than the U.S. No. 200 mesh
sieve. The results of the sieve analyses were plotted, and were classified in general accordance with the
Unified Soil Classification System and are presented in Figure B-1.
It should be noted that the sieve analyses were performed on soils obtained from samplers that have an
opening size of 1½ inches, so larger sized particles can’t be obtained by the samplers. Therefore, the sieve
results do not account for soil particles that are larger than 1½ inches. Soils with larger sized materials are
described in this report qualitatively based on visual observations and experience on projects where
excavations were made into similar formations.
September 16, 2016 | Page B-1 File No. 2202-024-00
0
10
20
30
40
50
60
70
80
90
100
0.0010.010.11101001000PERCENT PASSING BY WEIGHT GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE SIZE
SAND SILT OR CLAYCOBBLESGRAVEL
COARSE MEDIUM FINECOARSEFINE
Boring Number
Depth
(feet)Soil Description
GEI-8
GEI-10
2.5
5
Silty fine to medium sand with gravel (SM)
Silty fine sand with occasional gravel (SM)
Symbol
Moisture
(%)
8
17
3/8”3”1.5”#4 #10 #20 #40 #60 #1003/4”Figure B-1Sieve Analysis ResultsValley Medical Center Medical Office BuildingRenton, WA2202-024-00 Date Exported: 04/8/16
Note:This report may not be reproduced,except in full,without written approval of GeoEngineers,Inc.Test results are applicable only to the specific sample on which they were
performed,and should not be interpreted as representative of any other samples obtainedat othertimes,depths or locations,or generated by separate operations orprocesses.
Thegrain size analysis resultswereobtained in general accordance with ASTM D 6913.
#200
APPENDIX C Boring Logs from Previous Studies
APPENDIX C
BORING LOGS FROM PREVIOUS STUDIES
Included in this section are logs from previous studies completed in the immediate vicinity of the project
site:
■ The log of seven borings (GEI-1 through GEI-7) completed by GeoEngineers and presented in the Valley
Medical Center FY 2017 Parking Garage Geotechnical Report dated May 6, 2016 as task one of this
study.
■ The log of one boring (B-1) and eight test pits (21 through 28) completed by Converse Consultants NW
in 1987 for the Valley Medical Center Garage project;
■ The log of one boring (B-2) completed by Converse Consultants NW in 1989 for the Valley Medical
Center Garage Phase II project;
■ The logs of seven borings (B-1 through B-7) completed by Terra Associates in 1987 for the Valley
Medical Center Office Building project; and
■ The logs of four borings (B-1 through B-4) and two hand augers (HA-1 and HA-2) completed by
GeoEngineers in 2001 for the Warehouse Office Building project.
September 16, 2016 | Page C-1 File No. 2202-024-00
1A%F
1B
2
3%F
4
5
6
18
18
18
18
17
18
14
13
22
66
85/11"
71
3 inches asphalt concrete pavement
3 inches base course
Brown silty fine to medium sand with gravel(medium dense, moist) (fill)
Brown to gray sandy silt (stiff, moist)
Brown silty fine to medium sand (mediumdense, moist)
With occasional gravel
Gray silty fine to medium sand with gravel(medium dense, moist) (weathered glacialtill)
Gray silty fine to medium sand with gravel (very
dense, moist) (glacial till)
AC
GP
SM
ML
SM
SM
SM
Oxidation staining, till-fill
53
46
35
13
TotalDepth (ft)
HammerData
SystemDatum
Start End
Checked By
Logged By
DTMDrilled
Notes:
SJB
Surface Elevation (ft)
Vertical Datum
Driller
Groundwater Depth toWater (ft)Date Measured Elevation (ft)
Easting (X)Northing (Y)
Diedrich D50 Track Rig
Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger26.5
Autohammer140 (lbs) / 30 (in) Drop
DrillingEquipment
4/4/20164/4/2016
Not encountered
76.39
NAVD88
1298928.83
165386.17
WA State Plane,North
NAD83 (feet)
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)0
5
10
15
20 IntervalElevation (feet)7570656055Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-1
Valley Medical Center - Parking Garage Project
Renton, Washington
2202-024-00 Task 100
Project:
Project Location:
Project Number:Figure A-2
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FinesContent (%)MoistureContent (%)
71783/11"
White to light gray fine to medium sand (verydense, moist) (Renton FormationSandstone)
SM Smoother drilling at 22 feet
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)25 IntervalElevation (feet)50Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-1 (continued)
Valley Medical Center - Parking Garage Project
Renton, Washington
2202-024-00 Task 100
Project:
Project Location:
Project Number:Figure A-2
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FinesContent (%)MoistureContent (%)
1
2
3
4%F
5
6
7
8
10
3
14
18
18
18
19
27
50/3"*
12
14
75
54
1 inch crushed gravel surfacing (parking lot
surface)
Brown silty fine to medium sand with gravel andorganics (medium dense, moist) (fill)
Brown silty fine to medium sand with gravel(medium dense, moist)
Becomes gray
Gray silty fine to medium sand with occasionalgravel (very dense, wet) (glacial till)
Becomes moist
GP
SM
SM
ML
Oxidation staining/orange mottling, till-fill
Oxidation staining
*Blowcount overstated, sampler bouncing on
rock during sampling
Water in sampler
3414
TotalDepth (ft)
HammerData
SystemDatum
Start End
Checked By
Logged By
DTMDrilled
Notes:
SJB
Surface Elevation (ft)
Vertical Datum
Driller
Groundwater Depth toWater (ft)Date Measured Elevation (ft)
Easting (X)Northing (Y)
Diedrich D50 Track Rig
Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger31
Autohammer140 (lbs) / 30 (in) Drop
DrillingEquipment
4/4/20164/4/2016
See remarks
90.28
NAVD88
1299094.03
165403.44
WA State Plane,North
NAD83 (feet)
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)0
5
10
15
20 IntervalElevation (feet)9085807570Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-2
Valley Medical Center - Parking Garage Project
Renton, Washington
2202-024-00 Task 100
Project:
Project Location:
Project Number:Figure A-3
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FinesContent (%)MoistureContent (%)
8
9
18
11.5
61
50/5.5"
White to light gray silty fine to medium sandwith interbedded black coal (very dense,moist) (Renton Formation Sandstone)
Gray to brown silt with trace interbeds of blackcoal (hard, dry)
SM
ML
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)25
30 IntervalElevation (feet)6560Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-2 (continued)
Valley Medical Center - Parking Garage Project
Renton, Washington
2202-024-00 Task 100
Project:
Project Location:
Project Number:Figure A-3
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FinesContent (%)MoistureContent (%)
1MC
2
3
4
5
6
7
10
18
12
9
18
10
14
3
25
12
50/3"
48
84
78
1.5 inches crushed gravel surfacing (parking lot
surface)
Brown silty fine to medium sand with gravel(very loose to medium dense, moist) (fill)
With occsaional gravel and occasional coalfragments
Grades to gray
Gray silty fine to medium sand with occasional
gravel (dense to very dense, moist) (glacialtill)
GP
SM
SM
Orange mottling
Wet sampler
20
TotalDepth (ft)
HammerData
SystemDatum
Start End
Checked By
Logged By
DTMDrilled
Notes:
SJB
Surface Elevation (ft)
Vertical Datum
Driller
Groundwater Depth toWater (ft)Date Measured Elevation (ft)
Easting (X)Northing (Y)
Diedrich D50 Track Rig
Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger31.5
Autohammer140 (lbs) / 30 (in) Drop
DrillingEquipment
4/4/20164/4/2016
See remarks
87.92
NAVD88
1299048.22
165275.15
WA State Plane,North
NAD83 (feet)
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)0
5
10
15
20 IntervalElevation (feet)85807570Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-3
Valley Medical Center - Parking Garage Project
Renton, Washington
2202-024-00 Task 100
Project:
Project Location:
Project Number:Figure A-4
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FinesContent (%)MoistureContent (%)
8
9
8
13
41
76
Transitioned to sandier layer
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)25
30 IntervalElevation (feet)6560Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-3 (continued)
Valley Medical Center - Parking Garage Project
Renton, Washington
2202-024-00 Task 100
Project:
Project Location:
Project Number:Figure A-4
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FinesContent (%)MoistureContent (%)
1%F
2
3A
3B
4A4B
5
6
18
18
18
11
8
3
6
9
6
20
38
50/3"
1 inch crushed gravel surfacing (parking lot
surface)
Brown silty fine to medium sand with gravel(loose, moist) (fill)
Gray to brown silt with sand (medium stiff,moist to wet)
Gray silty fine to medium sand with gravel(medium dense, moist) (weathered glacialtill)
Gray silty fine to medium sand with gravel(dense to very dense, moist) (glacial till)
Obstruction encountered
GP
SM
ML
SM
SM
Perched water
Oxidation staining
Perched water
Boring could not be advanced further; practicalrefusal met
4920
TotalDepth (ft)
HammerData
SystemDatum
Start End
Checked By
Logged By
DTMDrilled
Notes:
SJB
Surface Elevation (ft)
Vertical Datum
Driller
Groundwater Depth toWater (ft)Date Measured Elevation (ft)
Easting (X)Northing (Y)
Diedrich D50 Track Rig
Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger15.5
Autohammer140 (lbs) / 30 (in) Drop
DrillingEquipment
4/4/20164/4/2016
Not encountered
96.7
NAVD88
1299202
165242.05
WA State Plane,North
NAD83 (feet)
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)0
5
10
15 IntervalElevation (feet)959085Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-4
Valley Medical Center - Parking Garage Project
Renton, Washington
2202-024-00 Task 100
Project:
Project Location:
Project Number:Figure A-5
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FinesContent (%)MoistureContent (%)
1
2
3%F
4A
4B
5%F
6
8
10
12
13
10
10
10
6
19
28
92/11.5"
56
1 inch crushed gravel surfacing (parking lot
surface)
Brown silty fine to medium sand with gravel andtrace organic debris (roots/wood) (loose to
medium dense, moist) (fill)
Brown silty fine to medium sand withoccasional gravel (medium dense, moist)(weathered glacial till)
Becomes brownish orange
Gray silty fine to medium sand with occasionalgravel (medium dense, moist) (glacial till)
Becomes very dense
GP
SM
SM
SM
Oxidation staining
Silt lenses
35
24
14
7
TotalDepth (ft)
HammerData
SystemDatum
Start End
Checked By
Logged By
DTMDrilled
Notes:
SJB
Surface Elevation (ft)
Vertical Datum
Driller
Groundwater Depth toWater (ft)Date Measured Elevation (ft)
Easting (X)Northing (Y)
Diedrich D50 Track Rig
Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger35.8
Autohammer140 (lbs) / 30 (in) Drop
DrillingEquipment
4/4/20164/4/2016
Not encountered
98.02
NAVD88
1299210.26
165309.34
WA State Plane,North
NAD83 (feet)
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)0
5
10
15
20 IntervalElevation (feet)95908580Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-5
Valley Medical Center - Parking Garage Project
Renton, Washington
2202-024-00 Task 100
Project:
Project Location:
Project Number:Figure A-6
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FinesContent (%)MoistureContent (%)
7
8
9
11.5
10
10
50/5.5"
50/4"
50/4"
White to light gray silty fine to medium sand(very dense, moist) (Renton FormationSandstone)
SM
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)25
30
35 IntervalElevation (feet)757065Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-5 (continued)
Valley Medical Center - Parking Garage Project
Renton, Washington
2202-024-00 Task 100
Project:
Project Location:
Project Number:Figure A-6
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FinesContent (%)MoistureContent (%)
1
2%F
3
4
5
6
12
12
5
18
18
18
29
36
37
52
75
65
3 inches asphalt concrete pavement
2 inches base course
Brown silty fine to medium sand with gravel(medium dense, moist) (fill)
Brown silty fine to medium sand withoccasional gravel (medium dense, moist)(weathered glacial till)
Gray silty fine to medium sand with occasionalgravel (dense, moist) (glacial till)
Becomes very dense
Increasing gravel content
AC
GP
SM
SM
SM
Oxidation staining
3910
TotalDepth (ft)
HammerData
SystemDatum
Start End
Checked By
Logged By
DTMDrilled
Notes:
SJB
Surface Elevation (ft)
Vertical Datum
Driller
Groundwater Depth toWater (ft)Date Measured Elevation (ft)
Easting (X)Northing (Y)
Diedrich D50 Track Rig
Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger21.5
Autohammer140 (lbs) / 30 (in) Drop
DrillingEquipment
4/4/20164/4/2016
Not encountered
75.8
NAVD88
1298925.69
165180.99
WA State Plane,North
NAD83 (feet)
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)0
5
10
15
20 IntervalElevation (feet)7570656055Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-6
Valley Medical Center - Parking Garage Project
Renton, Washington
2202-024-00 Task 100
Project:
Project Location:
Project Number:Figure A-7
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FinesContent (%)MoistureContent (%)
1
2%F
3
4
5
6
5
18
0
6
12
14
50/6"*
60
50/3"
50/5"
50/6"
56
2 inches asphalt concrete pavement
1.5 inch base course
Brown silty fine to coarse sand and gravel (verydense, moist) (fill)
Brown silty fine to medium sand with gravel(very dense, moist) (weathered glacial till)
Gray silty fine to medium sand with gravel (verydense, moist) (glacial till)
Becomes with occasional gravel
AC
GP
SM
SM
SM
*Sampler bouncing on rock, blowcountoverstated
Oxidation staining
No recovery
Slow drilling
Rougher drilling
2810
TotalDepth (ft)
HammerData
SystemDatum
Start End
Checked By
Logged By
DTMDrilled
Notes:
SJB
Surface Elevation (ft)
Vertical Datum
Driller
Groundwater Depth toWater (ft)Date Measured Elevation (ft)
Easting (X)Northing (Y)
Diedrich D50 Track Rig
Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger30.8
Autohammer140 (lbs) / 30 (in) Drop
DrillingEquipment
4/4/20164/4/2016
Not encountered
87.53NAVD88
1299051.08
165090.91
WA State Plane,North
NAD83 (feet)
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)0
5
10
15
20 IntervalElevation (feet)85807570Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-7
Valley Medical Center - Parking Garage Project
Renton, Washington
2202-024-00 Task 100
Project:
Project Location:
Project Number:Figure A-8
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FinesContent (%)MoistureContent (%)
7
8
6
10
50/5"
50/4"
Note: See Figure A-1 for explanation of symbols.
FIELD DATA
Depth (feet)25
30 IntervalElevation (feet)6560Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL
DESCRIPTION
GroupClassificationWater LevelLog of Boring GEI-7 (continued)
Valley Medical Center - Parking Garage Project
Renton, Washington
2202-024-00 Task 100
Project:
Project Location:
Project Number:Figure A-8
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FinesContent (%)MoistureContent (%)
APPENDIX D Report Limitations and Guidelines For Use
APPENDIX D
REPORT LIMITATIONS AND GUIDELINES FOR USE1
This appendix provides information to help you manage your risks with respect to the use of this report.
Geotechnical Services Are Performed for Specific Purposes, Persons and Projects
This report has been prepared for the exclusive use of Valley Medical Center (VMC) and other project team
members for the VMC FY 2017 Medical Office Building Project. This report is not intended for use by others,
and the information contained herein is not applicable to other sites.
GeoEngineers structures our services to meet the specific needs of our clients. For example, a geotechnical
or geologic study conducted for a civil engineer or architect may not fulfill the needs of a construction
contractor or even another civil engineer or architect that are involved in the same project. Because each
geotechnical or geologic study is unique, each geotechnical engineering or geologic report is unique,
prepared solely for the specific client and project site. Our report is prepared for the exclusive use of our
Client. No other party may rely on the product of our services unless we agree in advance to such reliance
in writing. This is to provide our firm with reasonable protection against open-ended liability claims by third
parties with whom there would otherwise be no contractual limits to their actions. Within the limitations of
scope, schedule and budget, our services have been executed in accordance with our Agreement with the
Client and generally accepted geotechnical practices in this area at the time this report was prepared. This
report should not be applied for any purpose or project except the one originally contemplated.
A Geotechnical Engineering or Geologic Report Is Based on a Unique Set of Project-specific
Factors
This report has been prepared for the VMC FY 2017 Medical Office Building Project in Renton, Washington.
GeoEngineers considered a number of unique, project-specific factors when establishing the scope of
services for this project and report. Unless GeoEngineers specifically indicates otherwise, do not rely on
this report if it was:
■not prepared for you,
■not prepared for your project,
■not prepared for the specific site explored, or
■completed before important project changes were made.
For example, changes that can affect the applicability of this report include those that affect:
■the function of the proposed structure;
■elevation, configuration, location, orientation or weight of the proposed structure;
1 Developed based on material provided by GBA, GeoProfessional Business Association; www.geoprofessional.org.
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■composition of the design team; or
■project ownership.
If important changes are made after the date of this report, GeoEngineers should be given the opportunity
to review our interpretations and recommendations and provide written modifications or confirmation, as
appropriate.
Subsurface Conditions Can Change
This geotechnical or geologic report is based on conditions that existed at the time the study was performed.
The findings and conclusions of this report may be affected by the passage of time, by manmade events
such as construction on or adjacent to the site, or by natural events such as floods, earthquakes, slope
instability or groundwater fluctuations. Always contact GeoEngineers before applying a report to determine
if it remains applicable.
Most Geotechnical and Geologic Findings Are Professional Opinions
Our interpretations of subsurface conditions are based on field observations from widely spaced sampling
locations at the site. Site exploration identifies subsurface conditions only at those points where subsurface
tests are conducted or samples are taken. GeoEngineers reviewed field and laboratory data and then
applied our professional judgment to render an opinion about subsurface conditions throughout the site.
Actual subsurface conditions may differ, sometimes significantly, from those indicated in this report. Our
report, conclusions and interpretations should not be construed as a warranty of the subsurface conditions.
Geotechnical Engineering Report Recommendations Are Not Final
Do not over-rely on the preliminary construction recommendations included in this report. These
recommendations are not final, because they were developed principally from GeoEngineers’ professional
judgment and opinion. GeoEngineers’ recommendations can be finalized only by observing actual
subsurface conditions revealed during construction. GeoEngineers cannot assume responsibility or liability
for this report's recommendations if we do not perform construction observation.
Sufficient monitoring, testing and consultation by GeoEngineers should be provided 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 from those
anticipated, and to evaluate whether or not earthwork activities are completed in accordance with our
recommendations. Retaining GeoEngineers for construction observation for this project is the most
effective method of managing the risks associated with unanticipated conditions.
A Geotechnical Engineering or Geologic Report Could Be Subject to Misinterpretation
Misinterpretation of this report by other design team members can result in costly problems. You could
lower that risk by having GeoEngineers confer with appropriate members of the design team after
submitting the report. Also retain GeoEngineers to review pertinent elements of the design team's plans
and specifications. Contractors can also misinterpret a geotechnical engineering or geologic report. Reduce
that risk by having GeoEngineers participate in pre-bid and preconstruction conferences, and by providing
construction observation.
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Do Not Redraw the Exploration Logs
Geotechnical engineers and geologists prepare final boring and testing logs based upon their interpretation
of field logs and laboratory data. To prevent errors or omissions, the logs included in a geotechnical
engineering or geologic report should never be redrawn for inclusion in architectural or other design
drawings. Only photographic or electronic reproduction is acceptable, but recognize that separating logs
from the report can elevate risk.
Give Contractors a Complete Report and Guidance
Some owners and design professionals believe they can make contractors liable for unanticipated
subsurface conditions by limiting what they provide for bid preparation. To help prevent costly problems,
give contractors the complete geotechnical engineering or geologic report, but preface it with a
clearly written letter of transmittal. In that letter, advise contractors that the report was not prepared for
purposes of bid development and that the report's accuracy is limited; encourage them to confer with
GeoEngineers and/or to conduct additional study to obtain the specific types of information they need or
prefer. A pre-bid conference can also be valuable. Be sure contractors have sufficient time to perform
additional study. Only then might an owner be in a position to give contractors the best information
available, while requiring them to at least share the financial responsibilities stemming from unanticipated
conditions. Further, a contingency for unanticipated conditions should be included in your project budget
and schedule.
Contractors Are Responsible for Site Safety on Their Own Construction Projects
Our geotechnical recommendations are not intended to direct the contractor’s procedures, methods,
schedule or management of the work site. The contractor is solely responsible for job site safety and for
managing construction operations to minimize risks to on-site personnel and to adjacent properties.
Read These Provisions Closely
Some clients, design professionals and contractors may not recognize that the geoscience practices
(geotechnical engineering or geology) are far less exact than other engineering and natural science
disciplines. This lack of understanding can create unrealistic expectations that could lead to
disappointments, claims and disputes. GeoEngineers includes these explanatory “limitations” provisions in
our reports to help reduce such risks. Please confer with GeoEngineers if you are unclear how these “Report
Limitations and Guidelines for Use” apply to your project or site.
Geotechnical, Geologic and Environmental Reports Should Not Be Interchanged
The equipment, techniques and personnel used to perform an environmental study differ significantly from
those used to perform a geotechnical or geologic study and vice versa. For that reason, a geotechnical
engineering or geologic report does not usually relate any environmental findings, conclusions or
recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated
contaminants. Similarly, environmental reports are not used to address geotechnical or geologic concerns
regarding a specific project.
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Biological Pollutants
GeoEngineers’ Scope of Work specifically excludes the investigation, detection, prevention or assessment
of the presence of Biological Pollutants. Accordingly, this report does not include any interpretations,
recommendations, findings, or conclusions regarding the detecting, assessing, preventing or abating of
Biological Pollutants and no conclusions or inferences should be drawn regarding Biological Pollutants, as
they may relate to this project. The term “Biological Pollutants” includes, but is not limited to, molds, fungi,
spores, bacteria, and viruses, and/or any of their byproducts.
If Client desires these specialized services, they should be obtained from a consultant who offers services
in this specialized field.
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