HomeMy WebLinkAboutEx14_Geotechnical Engineering Services ReportGeotechnical Engineering Services
Logan Avenue North and North 8th Street
Development Project
Renton, Washington
for
ARCO Murray Design Build
October 29, 2019
Geotechnical Engineering Services
Logan Avenue North and North 8th Street
Development Project
Renton, Washington
for
ARCO Murray Design Build
October 29, 2019
17425 NE Union Hill Road, Suite 250
Redmond, Washington 98052
425.861.6000
October 29, 2019| Page i File No. 23325-001-00
Table of Contents
1.0 INTRODUCTION ................................................................................................................................................. 1
1.1. Project Understanding .............................................................................................................................. 1
2.0 FIELD EXPLORATIONS AND LABORATORY TESTING .................................................................................... 1
2.1. Field Explorations ...................................................................................................................................... 1
2.2. Laboratory Testing .................................................................................................................................... 1
3.0 SITE CONDITIONS ............................................................................................................................................. 2
3.1. Surface Conditions.................................................................................................................................... 2
3.2. Subsurface Soil Conditions ...................................................................................................................... 2
3.3. Groundwater Conditions ........................................................................................................................... 2
4.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................................................... 3
4.1. Earthquake Engineering ........................................................................................................................... 4
4.1.1. Site-Specific Response Spectrum ................................................................................................ 4
4.1.2. Seismic Hazards ............................................................................................................................ 5
4.2. Building Foundations ................................................................................................................................ 6
4.2.1. Augercast Piles .............................................................................................................................. 6
4.2.2. Shallow Foundations ..................................................................................................................... 9
4.2.3. Ground Improvement .................................................................................................................. 11
4.3. Lowest-Level Building Slab ..................................................................................................................... 12
4.3.1. Subgrade Preparation ................................................................................................................. 12
4.3.2. Design Features .......................................................................................................................... 12
4.4. Net Poles ................................................................................................................................................. 13
4.4.1. General ......................................................................................................................................... 13
4.5. Outfield and Pavement Area Settlement Mitigation ............................................................................. 14
4.5.1. Surcharge and Preload Program ................................................................................................ 14
4.6. Below-Grade Walls .................................................................................................................................. 15
4.6.1. Drainage ....................................................................................................................................... 16
4.7. Earthwork ................................................................................................................................................ 16
4.7.1. Clearing and Site Preparation ..................................................................................................... 16
4.7.2. Subgrade Preparation ................................................................................................................. 17
4.7.3. Subgrade Protection .................................................................................................................... 17
4.7.4. Structural Fill................................................................................................................................ 17
4.7.5. Temporary Cut Slopes ................................................................................................................. 20
4.7.6. Permanent Cut and Fill Slopes ................................................................................................... 21
4.7.7. Erosion and Sediment Control .................................................................................................... 21
4.7.8. Utility Trenches ............................................................................................................................ 21
4.8. Pavement Recommendations ................................................................................................................ 22
4.8.1. Subgrade Preparation ................................................................................................................. 22
4.8.2. New Hot-Mix Asphalt Pavement ................................................................................................. 22
4.8.3. Portland Cement Concrete Pavement ........................................................................................ 22
4.9. Construction Dewatering ........................................................................................................................ 23
4.10.Infiltration Considerations ...................................................................................................................... 23
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4.11.Recommended Additional Geotechnical Services ................................................................................ 23
5.0 LIMITATIONS .................................................................................................................................................. 24
6.0 REFERENCES ................................................................................................................................................. 24
LIST OF FIGURES
Figure 1. Vicinity Map
Figure 2. Site Plan
Figure 3. Cross Section A-A’
Figure 4. Cross Section B-B’
Figure 5. Cross Section C-C’
Figure 6. Cross Section D-D’
Figure 7. Recommended Site-Specific MCER Response Spectrum
APPENDICES
Appendix A. Field Explorations
Figure A-1 – Key to Exploration Logs
Figures A-2 through A-26 – Log of Explorations
Appendix B. Laboratory Testing
Figures B-1 through B-5 – Sieve Analysis Results
Figures B-6 through B-10– Atterberg Limits Test Results
Appendix C. Site-Specific Seismic Response Analysis
Figure C-1. As-recorded Response Spectra 2,475-year Event
Figure C-2. Spectrally Matched and Filtered Response Spectra
Figure C-3. Shear Wave Velocity Profiles – Shallow
Figure C-4. Shear Wave Velocity Profiles – Deep
Figure C-5. Soil Amplification Factor, Lower Bound Profile 2,475-year Event
Figure C-6. Soil Amplification Factors, Upper Bound Profile 2,475-year Event
Figure C-7. Soil Amplification Factors, Porfile Comparison 2,475-year Event
Figure C-8. Probabilistic MCE Response Spectrum Comparison
Figure C-9. Deterministic MCEr Response Spectrum (Seattle Fault, Mw=7.2, Rrup=2.9 km)
Figure C-10. Recommended Site-Specific MCER Response Spectrum
Appendix D. Report Limitations and Guidelines for Use
October 29, 2019 | Page 1 File No. 23325-001-00
1.0 INTRODUCTION
This report presents the results of GeoEngineers, Inc.’s (GeoEngineers) geotechnical engineering services
for the proposed development project located at Logan Avenue North and North 8th Street in Renton,
Washington. The site is shown relative to surrounding physical features on Figure 1, Vicinity Map and
Figure 2, Site Plan.
The purpose of this report is to provide geotechnical engineering conclusions and recommendations for the
design of the proposed development. GeoEngineers’ geotechnical engineering services have been
completed in general accordance with the scope of services outlined in our Agreement for Professional
Services dated March 22, 2018, Change Order No. 1 dated April 16, 2018, and Change Order No. 2 dated
July 16, 2019.
1.1. Project Understanding
GeoEngineers understands that the proposed development consists of a low-rise structure, an outfield area
consisting of turf or lawn and enclosed with nets supported by poles up to 170 feet in height, an
aboveground parking garage (up to two levels high) and surface parking. Our understanding of the project
and the required geotechnical scope of services is based on information provided by Eric Uebelhor with
Arco Murray Design Build.
2.0 FIELD EXPLORATIONS AND LABORATORY TESTING
2.1. Field Explorations
The subsurface conditions at the site were evaluated by drilling 24 borings (B-1, B-2, PB-1, AB-1 through
AB-3, OB-1 through OB-7, GEI-1, GEI-2, B-1-19 through B-4-19, and GEI-1-19 through GEI-5-19) and
advancing six cone penetration tests (CPTs) (CPT-1 through CPT-6) to depths ranging from approximately
10 to 85 feet below existing site grades. CPTs were advanced to practical refusal. In addition, one
groundwater monitoring well (GEI-3-19a) was drilled and installed next to boring GEI-3-19. The approximate
locations of the explorations are shown in Figure 2. Descriptions of the field exploration program and the
boring and CPT logs are presented in Appendix A, Field Explorations.
2.2. Laboratory Testing
Soil samples were obtained during drilling and were taken to GeoEngineers’ laboratory for further
evaluation. Selected samples were tested for the determination of moisture content, fines content, grain-
size distribution, and plasticity indices (Atterberg limits). A description of the laboratory testing and the test
results are presented in Appendix B, Laboratory Testing.
October 29, 2019 | Page 2 File No. 23325-001-00
3.0 SITE CONDITIONS
3.1. Surface Conditions
The site is bounded by office and parking structures to the south, Park Avenue North to the east,
North 8th Street to the north, and Logan Avenue North to the west. The site is relatively flat, with up to 3 feet
grade difference throughout.
The site is currently unoccupied, overall vegetated with grassy areas with some pavement associated with
previous site development. Based on our review of historical aerial photographs (available on Google Earth),
the site was previously occupied by warehouse structures that were demolished between 2005 and 2007.
Underground utilities running below and adjacent to the site consist of storm and sanitary sewer, water,
power and communications.
3.2. Subsurface Soil Conditions
GeoEngineers’ understanding of subsurface conditions is based on the results of our exploration program,
as described in the ‘Field Explorations’ section of this report. The approximate locations of the explorations
are presented in Figure 2.
The soils encountered at the site consist of relatively shallow fill overlying alluvial deposits, as shown in
Figures 3 through 6, Cross Sections A-A’ through D-D’, respectively, and the boring logs presented in
Appendix A.
Fill was encountered in each of the borings. Fill was observed below the pavement or topsoil, and generally
consisted of loose to dense sand with varying silt and gravel content. A thin layer of stiff sandy silt with
occasional gravel was encountered within the fill unit in boring B-1. The thickness of fill ranged from 4 feet
up to approximately 8 feet across the site.
Alluvium was observed below the fill. The alluvium typically consists of three units:
■ Upper loose/soft to medium dense/medium stiff alluvial sand to silty sand and silt with thin layers of
soft to medium stiff peat;
■ Lower medium dense to dense/stiff alluvial gravel, sand to silty sand and silt; and
■ Within the lower alluvial zone a loose/medium stiff sand and silt alluvium layer with thin layers of stiff
peat.
3.3. Groundwater Conditions
Based on conditions observed during drilling, the groundwater table at the site could range from depths of
approximately 4 to 13 feet below the existing ground surface (bgs), which corresponds to approximately
Elevations 17 to 25 feet (North American Vertical Datum of 1988 [NAVD 88]). A monitoring well was
installed next to boring GEI-3-19 to observe the depth of groundwater at the site. Measurements completed
approximately 3 weeks following the well installation indicate that the site groundwater level is about
8.2 feet below existing grades, which corresponds to approximately Elevation 21.8 feet (NAVD 88).
October 29, 2019 | Page 3 File No. 23325-001-00
The table below provides a summary of the monitoring well and groundwater measurements at the site.
TABLE 1. GROUNDWATER MEASUREMENTS
Well ID
Ground Surface
Elevation
(feet)
Depth to Bottom
of Casing
(feet bgs)
Well Screen
Interval
(feet bgs)
Measured
Groundwater
Depth (feet bgs)
Measured
Groundwater Elevation
(feet bgs)
GEI-3-19a 30 16 5 to 15
8.0 (8/8/19)
8.1 (8/12/19)
8.2 (8/23/19)
22.0 (8/8/19)
21.9 (8/12/19)
21.8 (8/23/19)
Groundwater observations represent conditions observed during exploration and may not represent the
groundwater conditions throughout the year. Groundwater seepage is expected to fluctuate as a result of
season, precipitation and other factors.
4.0 CONCLUSIONS AND RECOMMENDATIONS
A summary of the geotechnical considerations is provided below. The summary is presented for introductory
purposes only and should be used in conjunction with the complete recommendations provided in
this report.
■ The site is designated as seismic Site Class F per the 2015 International Building Code (IBC) due to the
presence of potentially liquefiable soils below the building footprint. As a result, a site-specific seismic
response analysis has been completed and is included in Appendix C, Site Specific Seismic Response
Analysis. The building should be designed using the recommended risk-targeted maximum considered
earthquake (MCER) site-specific response spectrum presented in Table 1 and Figure 7, Recommended
Site-Specific MCER Response Spectrum.
■ The results of our liquefaction analyses indicate that fill and loose to medium dense alluvial soils, below
the groundwater table, are susceptible to liquefaction during the building code-prescribed
maximum-considered earthquake (MCE) event (i.e. earthquake event with 2,500-year return period).
We completed liquefaction-induced settlement analyses using the site-specific peak ground
acceleration (PGA) of 0.45g and mean earthquake magnitude of 7.2. Based on the results of our
liquefaction-induced settlement analysis, we estimate that free field ground surface settlement on the
order of 3 to 15 inches could occur during a MCE-level earthquake due to soil liquefaction.
■ Foundation support for the proposed building can be provided by augercast piles or by shallow
foundations bearing on improved ground. For shallow foundations bearing on improved ground, an
allowable static bearing pressure of 6,000 pounds per square foot (psf) can be used for ground
improvement consisting of rigid inclusions with an area replacement ratio of 10 to 12 percent. The
estimated post-construction static foundation settlement of new footings, prepared as described in this
report, is estimated to be less than 1 inch.
■ Design of the at-grade slabs should consider site settlements. In addition to being susceptible to
liquefaction, the upper alluvial soils are compressible and can be anticipated to settle under new loads.
Static settlements will depend on the thickness of new fill placed in the building footprint. If slab areas
are not supported on deep foundations or improved ground or treated with a preload program,
long-term static settlement is anticipated to be greater than 1 inch. The at-grade floor slab for the
October 29, 2019 | Page 4 File No. 23325-001-00
building should be underlain by at least 6 inches of clean crushed rock for uniform support and as a
capillary break.
■ Based on site grading plans, we understand that new site fills will range up to about 7 feet in thickness
in the outfield and 3 feet in thickness below the building footprint. Up to 5½ inches of long-term static
settlement are estimated for new site fill of up to 7 feet in thickness. Where long-term static settlement
is not desirable, they can be mitigated using deep foundations, ground improvement or a surcharge
and preload program.
■ The feasibility of infiltration was assessed at the site through review of near surface soil conditions and
groundwater levels. Due to relatively shallow groundwater (as shallow as 4 feet based on observations
during drilling) and the presence of low permeability silt soils near the ground surface, we conclude
that the use of large scale infiltration facilities is not feasible at this site.
4.1. Earthquake Engineering
4.1.1. Site-Specific Response Spectrum
A site-specific response analysis was completed in accordance with the procedure outlined in Chapter 21
of the American Society of Civil Engineers (ASCE) 7-10 code to develop the site-specific MCER response
spectrum. The methodology used and the details of the site-specific ground response analyses are
presented in Appendix C. The recommended MCER site-specific response spectrum is presented in Figure 7
and is defined in Table 1. The design spectrum is taken as two thirds of the MCER values presented in
Table 2 per ASCE 7-10 Section 21.3.
TABLE 2. RECOMMENDED SITE-SPECIFIC MCER RESPONSE SPECTRUM
Period (sec) Sa (g)
0.01 0.45
0.05 0.71
0.075 0.79
0.10 0.86
0.20 1.04
0.30 1.04
0.40 1.04
0.50 1.04
0.75 1.04
1.00 1.04
2.00 0.68
3.00 0.40
4.00 0.26
5.00 0.21
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4.1.2. Seismic Hazards
4.1.2.1. Surface Fault Rupture
The site is located about 2.4 miles south of the Seattle Fault zone. Based on the distance from mapped
faults, it is our opinion there is a low risk of fault rupture at the site.
4.1.2.2. Liquefaction Potential
Liquefaction refers to a condition in which vibration or shaking of the ground, usually from earthquake
forces, results in development of high excess pore water pressures in saturated soils and subsequent loss
of stiffness and/or strength in the deposit of soil so affected. In general, soils that are susceptible to
liquefaction include loose to medium dense, clean to silty sands and low-plasticity silts that are below the
water table. Ground settlement, lateral spreading and/or sand boils may result from soil liquefaction.
Structures, such as buildings, supported on or within liquefied soils may experience foundation settlement
or lateral movement that can be damaging.
We evaluated the liquefaction potential of the site soils based on the information from the borings and
CPTs and using the Simplified Procedure (Youd and Idriss 2001 and Idriss and Boulanger 2008). The
Simplified Procedure is based on comparing the cyclic resistance ratio (CRR) of a soil layer (the cyclic shear
stress required to cause liquefaction) to the cyclic stress ratio (CSR) induced by an earthquake. The factor
of safety against liquefaction is determined by dividing the CRR by the CSR. Liquefaction hazards, including
settlement and related effects, were evaluated when the factor of safety against liquefaction was calculated
as less than 1.0.
Based on our analyses, the potential exists for liquefaction within the sandy and low-plasticity silt alluvial
deposits encountered in the explorations completed at the site. The cohesive soils (i.e. sandy silt
encountered within the alluvium soils) may also experience loss of shear strength during seismic loading.
We estimated the factor of safety to be less than 1.0 during a MCE event (i.e. earthquake event with
2,500-year return period), which has a rock outcrop peak ground acceleration (PGA) of 0.45g and mean
earthquake magnitude of 7.2 at the project site based on our site-specific response analysis.
4.1.2.3. Liquefaction-induced Settlement
Estimated ground settlement resulting from earthquake-induced liquefaction was analyzed using empirical
procedures based on correlations from the standard penetration test (SPT) results from the soil borings
(Tokimatsu and Seed 1987; Ishihara and Yoshimine 1992; Idriss and Boulanger 2008) and the tip
penetration resistance results from the CPTs. Liquefaction potential of the site soils was evaluated using
the PGA of 0.45g and mean earthquake magnitude of 7.2.
Liquefaction-induced ground settlement of the potentially liquefiable soils is estimated to be on the order
of 16 inches. Based on the research completed by Cetin et al. (2009), liquefaction at depths greater than
60 feet does not result in settlement that can be observed at the ground surface. In addition, the
liquefaction between depths of 40 to 60 feet results in settlement that is approximately one-third of
settlement estimated using empirical procedures. Therefore, we estimate the ground surface liquefaction-
induced settlement to be on the order of 3 to 15 inches, with the differential settlement between column
footings equal to the total estimated settlement.
4.1.2.4. Residual Strengths of Liquefiable Soils
The residual strength of liquefiable soils was estimated for use in our deep foundation capacity analysis.
The loose to medium dense sandy and low-plasticity silt alluvial deposits at depths shallower than 50 to
60 feet are susceptible to liquefaction and do not have strengths sufficient for deep foundation or ground
October 29, 2019 | Page 6 File No. 23325-001-00
improvement load bearing. However, the medium dense to dense alluvial deposits at depths greater than
50 to 60 feet, while including layers of soils that are potentially liquefiable under the design seismic event,
are estimated to have residual strength that will contribute to the capacity of deep foundations. The residual
strength of the medium dense to dense alluvial deposits was estimated using the method proposed by
Idriss and Boulanger (2008).
4.1.2.5. Lateral Spreading
Lateral spreading involves lateral displacements of large volumes of liquefied soil. Lateral spreading can
occur on near-level ground as blocks of surface soils are displaced relative to adjacent blocks. Lateral
spreading also occurs as blocks of surface soils are displaced toward a nearby slope or free-face such as
a nearby waterfront or stream bank by movement of the underlying liquefied soil. Due to the distance to a
nearby free-face and the relatively flat grade, it is our opinion the risk of lateral spreading is low.
4.2. Building Foundations
Based on the presence of the compressible peat and organic silt layers and the presence of the potentially
liquefiable soils, feasible foundation support for the proposed building can be provided by augercast piles
or by shallow foundations bearing on improved ground. Specific design and construction recommendations
for each of these options are presented in the following sections of this report.
4.2.1. Augercast Piles
Augercast piles are constructed using a continuous-flight, hollow-stem auger attached to a set of leads
supported by a crane or installed with a fixed-mast drill rig. The first step in the pile casting process consists
of drilling the auger into the ground to the specified tip elevation of the pile. Grout is then pumped through
the hollow-stem during steady withdrawal of the auger, replacing the soils on the flights of the auger.
The final step is to install a steel reinforcing cage and typically a center bar into the column of fresh grout.
One benefit of using augercast piles is that the auger provides support for the soils during the pile
installation process, thus eliminating the need for temporary casing or drilling fluid.
4.2.1.1. Construction Considerations
The augercast piles should be installed using a continuous-flight, hollow-stem auger. As is standard
practice, the pile grout must be pumped under pressure through the hollow stem as the auger is withdrawn.
Maintenance of adequate grout pressure at the auger tip is critical to reduce the potential for encroachment
of adjacent native soils into the grout column. The rate of withdrawal of the auger must remain constant
throughout the installation of the piles to reduce the potential for necking of the piles. Failure to maintain
a constant rate of withdrawal of the auger should result in immediate rejection of that pile. Reinforcing
steel for bending and uplift should be placed in the fresh grout column as soon as possible after withdrawal
of the auger. Centering devices should be used to provide concrete cover around the reinforcing steel.
The contractor should adhere to a waiting period of at least 12 hours between the installation of piles
spaced closer than 8 feet, center-to-center. This waiting period is necessary to avoid disturbing the curing
concrete in previously cast piles.
Grout pumps must be fitted with a volume-measuring device and pressure gauge so that the volume of
grout placed in each pile and the pressure head maintained during pumping can be observed. A minimum
grout line pressure of 100 pounds per square inch (psi) should be maintained. The rate of auger withdrawal
should be controlled during grouting such that the volume of grout pumped is equal to at least 115 percent
October 29, 2019 | Page 7 File No. 23325-001-00
of the theoretical pile volume. A minimum head of 10 feet of grout should be maintained above the auger
tip during withdrawal of the auger to maintain a full column of grout and to prevent hole collapse.
The geotechnical engineer of record should observe the drilling operations, monitor grout injection
procedures, record the volume of grout placed in each pile relative to the calculated volume of the hole and
evaluate the adequacy of individual pile installations.
4.2.1.2. Axial Capacity
Axial pile load capacity in compression is developed from end bearing and from side frictional resistance in
the lower medium dense to dense/stiff alluvial soils. Uplift pile capacity will also be developed from side
frictional resistance in these soils. Axial pile capacities are presented in Tables 3 and 4 below, for 18- and
24-inch-diameter augercast piles, respectively.
TABLE 3. ALLOWABLE AXIAL PILE CAPACITY – 18-INCH AUGERCAST PILES
Location
Minimum Pile Tip
Elevation (feet)
Static Capacity (kips) Seismic Capacity (kips)
Downward Uplift Downward Uplift
Main Building – North -46 160 75 75 150
Main Building – North -57 230 100 150 200
Main Building – South -46 230 80 75 150
Main Building – South -51 230 90 150 170
Parking Garage -51 200 80 90 180
Parking Garage -57 230 100 150 200
TABLE 4. ALLOWABLE AXIAL PILE CAPACITY – 24-INCH AUGERCAST PILES
Location
Minimum Pile Tip
Elevation
Static Capacity (kips) Seismic Capacity (kips)
Downward Uplift Downward Uplift
Main Building – North -46 250 100 100 200
Main Building – North -57 350 130 200 260
Main Building – South -46 350 100 100 200
Main Building – South -51 350 120 200 230
Parking Garage -51 350 110 120 200
Parking Garage -57 350 130 200 260
Allowable pile capacities were evaluated based on Allowable Stress Design (ASD) and are for combined
dead plus long-term live loads. The allowable capacities are based on the strength of the supporting soils
and include a factor of safety of 3 for end bearing, 2 for side friction and a factor of safety of 1.1 for seismic
conditions. The allowable seismic capacities include the effects of downdrag and the residual strength of
potentially liquefiable layers within the lower medium dense to dense alluvium. The capacities apply to
single piles. If piles are spaced at least three pile diameters on center, as recommended, no reduction of
axial capacity for group action is needed, in our opinion.
The structural characteristics of pile materials and structural connections may impose limitations on pile
capacities and should be evaluated by the structural engineer. For example, steel reinforcing will be needed
for augercast piles subjected to uplift or large bending moments.
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4.2.1.3. Lateral Capacity
Lateral loads can be resisted by passive soil pressure on the vertical piles and by the passive soil pressures
on the pile cap. Because of the potential separation between the pile-supported foundation components
and the underlying soil from settlement, base friction along the bottom of the pile cap should not be
included in calculations for lateral capacity.
Tables 5 and 6 summarize recommended design parameters for laterally loaded piles. We recommend that
these parameters be incorporated into the commercial software LPILE to evaluate response and capacity
of piles subject to laterally loading. For potentially liquefiable soils, a reduced p-multiplier should be applied
to the model P-Y curve of the relevant soil units for evaluating seismic conditions (Boulanger, et al. 2003).
TABLE 5. LPILE SOIL PARAMETERS – MAIN BUILDING
Soil Unit1
Approximate Depth Below
Ground Surface (feet) Effective
Unit
Weight
(pcf)
Friction
Angle
(degrees)
Stiffness
Parameter, k
(pci)
P-
Multiplier1
Top of Soil
Layer
Bottom of
Soil Layer
Fill 0 4 120 34 110 -
Upper Loose/Soft to
Medium
Dense/Medium Stiff
Alluvium
4 50 57.6 32 50 1 (static)
0.1 (seismic)
Lower Medium Dense
to Dense/Stiff
Alluvium
50 200 67.6 36 120 1 (static)
0.5 (seismic)
Notes:
1 Sand (Reese) Model
pcf – pounds per cubic foot
pci – pounds per cubic inch
TABLE 6. LPILE SOIL PARAMETERS – PARKING GARAGE
Soil Unit1
Approximate Depth Below
Ground Surface (feet) Effective
Unit
Weight
(pcf)
Friction
Angle
(degrees)
Stiffness
Parameter, k
(pci) P-Multiplier1
Top of Soil
Layer
Bottom of
Soil Layer
Fill 0 4 120 34 110 -
Upper Loose/Soft to
Medium
Dense/Medium Stiff
Alluvium
4 60 57.6 32 50 1 (static)
0.1 (seismic)
Lower Medium Dense
to Dense/Stiff
Alluvium
60 200 67.6 36 120 1 (static)
0.5 (seismic)
Notes:
1 Sand (Reese) Model
pcf – pounds per cubic foot
pci – pounds per cubic inch
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Piles spaced closer than five pile diameters apart will experience group effects that will result in a lower
lateral resistance for trailing rows of piles with respect to leading rows of piles for an equivalent deflection.
We recommend that the lateral load capacity for piles in a pile group spaced less than five pile diameters
apart be reduced in accordance with the factors in Table 7 per American Association of State Highway and
Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifications
Section 10.7.2.4.
TABLE 7. PILE P-MULTIPLIERS, PM, FOR MULTIPLE ROWS
Pile Spacing1
(In Terms of Pile Diameter)
P-Multipliers, Pm2, 3
Row 1 Row 2 Row 3 and Higher
3D 0.80 0.40 0.30
5D 1.00 0.85 0.70
Notes:
1 The P-multipliers presented are a function of the center-to-center spacing of piles in the group in the direction of loading expressed
in multiples of the pile diameter, D.
2 The values of Pm were developed for vertical piles only.
3 The P-multipliers are dependent on the pile spacing and the row number in the direction of the loading. To establish values of Pm
for other pile spacing values, interpolation between values should be conducted.
We recommend that the passive soil pressure acting on the pile cap be estimated using an equivalent fluid
density of 350 pounds per cubic foot (pcf) where the soil adjacent to the foundation consists of adequately
compacted structural fill. This passive resistance value includes a factor of safety of 1.5 and assumes a
minimum lateral deflection of 1 inch to fully develop the passive resistance. Deflections that are less than
1 inch will not fully mobilize the passive resistance in the soil.
4.2.1.4. Pile Settlement
We estimate that the post-construction settlement of pile foundations, designed and installed as
recommended, will be on the order of 1 inch or less. Maximum differential settlement should be less than
about one-half the post-construction settlement. Most of this settlement will occur rapidly as loads are
applied.
4.2.2. Shallow Foundations
4.2.2.1. Allowable Bearing Pressure
The building can be supported on shallow foundations provided the foundations bear on improved ground.
Rigid inclusion ground improvement was considered for this evaluation and is discussed in further detail in
the “Ground Improvement” section. For preliminary purposes, footings may be designed using a maximum
net allowable soil bearing value of 6,000 psf on properly-compacted structural fill consisting of at least a
2-foot-thick layer of crushed rock above ground improved with rigid inclusions with an area-replacement
ratio of about 10 to 12 percent. The net allowable soil bearing values 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.
4.2.2.2. Size and Embedment
The design frost depth for the Puget Sound area is 12 inches; therefore, we recommend that exterior
footings for the structures be founded at least 18 inches below lowest adjacent finished grade. Interior
footings should be founded at least 12 inches below bottom of slab or adjacent finished grade. For shallow
October 29, 2019 | Page 10 File No. 23325-001-00
foundation support, we recommend widths of at least 18 and 36 inches, respectively, for continuous wall
and isolated column footings supporting the proposed building.
4.2.2.3. Settlement
Provided all loose soil is removed and the subgrade is prepared as recommended under “Construction
Considerations” below, static settlement of shallow foundations bearing on improved ground is anticipated
to be less than 1 inch. The settlement will occur rapidly, essentially as loads are applied. Total settlement
(including liquefaction-induced settlement) of shallow foundations bearing on improved ground is
anticipated to be in the order of 2 to 4 inches. Differential settlements measured along 25 feet of wall
foundations or between similarly loaded column footings are expected to be less than 1 inch.
4.2.2.4. Lateral Resistance
Lateral foundation loads may be resisted by passive resistance on the sides of footings and by friction along
the base of the footings. For footings supported on structural fill placed and compacted in accordance with
our recommendations, the allowable frictional resistance may be computed using a coefficient of friction
of 0.35 applied to vertical dead-load forces.
The allowable passive resistance may be computed using an equivalent fluid density of 350 pcf (triangular
distribution). This value is appropriate for foundation elements that are surrounded by structural fill. The
structural fill should extend out from the face of the foundation element for a distance at least equal to
three times the height of the element and be compacted to at least 95 percent of the maximum dry density
(MDD).
The above coefficient of friction and passive equivalent fluid density values incorporate a factor of safety
of about 1.5.
4.2.2.5. Footing Drains
We recommend that perimeter footing drains be installed around the building where the lowest finished
floor is lower than adjacent site grades. The perimeter drains should be installed at the base of the exterior
footings. The perimeter drains should be provided with cleanouts and should consist of at least
4-inch-diameter perforated pipe placed on a 3-inch bed of, and surrounded by, 6 inches of drainage
material enclosed in a non-woven geotextile fabric such as Mirafi 140N (or approved equivalent) to prevent
fine soil from migrating into the drain material. We recommend that the drainpipe consist of either
heavy-wall solid pipe (SDR-35 polyvinyl chloride [PVC], or equal) or rigid corrugated smooth interior
polyethylene pipe (ADS N-12, or equal). We recommend against using flexible tubing for footing drainpipes.
The drainage material should consist of Gravel Backfill for Drains conforming to Section 9-03.12(4) of the
2018 Washington State Department of Transportation (WSDOT) Standard Specifications. The perimeter
drains should be sloped to drain by gravity to a suitable discharge point, preferably a storm drain. We
recommend that the cleanouts be covered and be placed in flush mounted utility boxes. Water collected in
roof downspout lines must not be routed to the footing drain lines.
4.2.2.6. Construction Considerations
Immediately prior to placing concrete, all debris and soil slough that accumulated in the footings during
forming and steel placement must be removed. Debris or loose soils not removed from the footing
excavations will result in increased settlement. We recommend that the footing excavations be cut using a
smooth-edged bucket to reduce the amount of disturbed soil exposed at the subgrade.
October 29, 2019 | Page 11 File No. 23325-001-00
If wet weather construction is planned, we recommend that all footing subgrades be protected using a lean
concrete mud mat. The mud mat should be placed the same day that the footing subgrade is excavated
and approved for foundation support.
The condition of all footing excavations should be observed by the Geotechnical Engineer to evaluate if the
work is completed in accordance with our recommendations and that the subsurface conditions are as
anticipated.
4.2.3. Ground Improvement
Ground improvement is recommended to mitigate potentially liquefiable soils and to control foundation
settlement. Based on our experience, rigid inclusions are a feasible and economical ground improvement
option for this site. GeoEngineers can design the ground improvement system in collaboration with the
general contractor and structural engineer. General recommendations are provided below for ground
improvement using rigid inclusions. During the design phase of the project, foundation support options
should be reviewed with the project team to determine the preferred foundation support alternative.
The purpose of ground improvement is to mitigate potential static and/or seismic induced settlement
resulting from consolidation and seismic liquefaction of the alluvial deposits. The benefits of ground
improvement for this site include:
■ Ground improvement will allow for conventional shallow foundations and slabs on grade, both of which
are anticipated to result in more efficient and more cost-effective construction; and
■ Ground improvement will mitigate the potential settlement resulting from liquefaction of the native
alluvial soils during the design seismic event to tolerable magnitudes.
4.2.3.1. Rigid Inclusions
Rigid inclusions consist of unreinforced lean concrete columns installed below the building foundation
elements on a variable grid pattern. The purpose of the rigid inclusions placed in a grid pattern is to provide
a significantly higher strength material capable of dissipating building loads in a less concentrated manner
and to provide a ‘block’ of a composite soil and lean concrete material that will reduce the potential for
differential settlement.
Advantages with the use of rigid inclusions include the following:
■ They are more economical than augercast piles (shorter length, no reinforcement and allows for the
use of conventional spread footings/slabs on grade);
■ There is minimal disturbance of adjacent structures during installation; and
■ There is a lower level of construction noise (i.e. no pile driving), there will be lesser impacts to nearby
businesses/residences/buried utilities during construction.
Rigid inclusions for this site would be constructed using similar techniques for installing augercast piles.
Where augercast methods are used, the first step in the rigid inclusion casting process consists of drilling
the auger into the ground to the specified tip elevation of the column. Grout is then pumped into the hole
through the base of the auger.
October 29, 2019 | Page 12 File No. 23325-001-00
The layout/design of the rigid inclusions will be completed once the building design has been finalized.
For preliminary design and pricing purposes, rigid inclusions may consist of the following:
■ 18- to 24-inch-diameter rigid inclusions constructed using 1,000 to 2,000 psi concrete.
■ An area of replacement of about 10 to 12 percent. The appropriate area replacement ratio and the
need for the rigid inclusions to extend beyond the edges of the foundation footprint will be influenced
by seismic total and differential settlement tolerances.
■ Rigid inclusions should extend 60 to 70 feet deep beginning about 2 feet below the bottom of
foundations and floor slabs.
■ Rigid inclusions should be located under shallow foundations and should extend a distance equals to
at least one spacing beyond the foundation footprint.
■ At least 2 feet of clean crushed rock with negligible sand and fines should be placed over the top of the
rigid inclusions under the floor slab and foundations. A woven soil stabilization geotextile should be
placed within this layer. In addition, a non-woven geotextile filter fabric should be used between the top
of the rigid inclusions and this layer to minimize migration of soil from the subgrade to the crushed rock
layer. This layer of crushed rock will help transfer loads from the foundations and slab-on-grade to the
rigid inclusions and will help reduce differential settlement.
GeoEngineers can assist the project team with preparation of the ground improvement plan and
specifications once the foundation layout and building loads have been finalized.
4.3. Lowest-Level Building Slab
4.3.1. Subgrade Preparation
Floor slab support will be dependent of the type of foundation support selected for the building, the
potential for long-term static settlement due to the building pad fill, and the tolerance for
liquefaction-induced settlement. If mitigation of static and/or liquefaction-induced settlement is required,
the slab can be supported structurally (augercast piles) or constructed as a slab-on-grade with ground
improvement below the slab (rigid inclusions). If settlement mitigation is not required, the slab can be
constructed as a slab-on-grade without ground improvement.
4.3.2. Design Features
We recommend that the floor slabs be underlain by a capillary break gravel layer consisting of at least
6 inches of clean crushed gravel meeting the requirements of Mineral Aggregate Type 22 (¾-inch crushed
gravel), City of Seattle Standard Specification 9-03.16. The gravel layer should be placed directly over
compacted structural fill. If a 2-foot-thick layer of crushed rock is placed as part of ground improvement
plans, it will also suffice as a capillary break layer. For slabs designed as a beam on an elastic foundation,
a modulus of subgrade reaction of 85 pounds per cubic inch (pci) may be used for subgrade soils prepared
as recommended above.
If water vapor migration through the slabs is objectionable, the gravel should be covered with a heavy
plastic sheet, such as 10-mil plastic sheeting, to act as a vapor retarder. This will be necessary in occupied
spaces and where the slabs will be surfaced with tile or will be carpeted. It may also be prudent to apply a
sealer to the slab to further retard the migration of moisture through the floor. The contractor should be
made responsible for maintaining the integrity of the vapor retarder during construction.
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4.4. Net Poles
4.4.1. General
Based on information provided by ARCO Murray, it is our understanding that typical net pole foundations
consist of 3-, 4- and 5-foot-diameter drilled concrete piles. The net pole foundations are to be designed by
others. The following sections present our design recommendations for each of the net pole foundation
sizes being considered for this project.
4.4.1.1. Axial Capacity
We understand that the net pole design is controlled by lateral capacity. Axial pile load capacity in
compression is developed from end bearing and from side frictional resistance in the underlying soils, and
uplift pile capacity will also be developed from side frictional resistance. Table 8 presents allowable axial
capacities for 3-, 4- and 5-foot-diameter drilled concrete piles embedded at least 15 feet into the lower
medium dense to dense/stiff alluvium. Allowable pile capacities were evaluated based on Allowable Stress
Design (ASD) and are for combined dead plus long-term live loads. The allowable capacities are based on
the strength of the supporting soils and include a factor of safety of 3 for end bearing, 2 for side friction
and a factor of safety of 1.1 for seismic conditions. The allowable seismic capacities include the effects of
downdrag and the residual strength of potentially liquefiable layers within the lower medium dense to
dense/stiff alluvium.
TABLE 8. ALLOWABLE STATIC AXIAL CAPACITY FOR NET POLE FOUNDATIONS
Foundation
Diameter
Minimum Pile Tip
Elevation (feet)
Static Capacity (kips) Seismic Capacity (kips)
Downward Uplift Downward Uplift
3-foot -42 230 110 150 230
4-foot -42 350 160 250 300
5-foot -42 500 200 350 400
The capacities apply to single piles. If piles are spaced at least three pile diameters on center, as
recommended, no reduction of axial capacity for group action is needed, in our opinion.
4.4.1.2. Lateral Capacity
Lateral loads can be resisted by passive soil pressure on the vertical piles for the net pole foundations.
Table 9 summarizes recommended design parameters for laterally loaded net pole foundations. We
recommend that these parameters be incorporated into the commercial software LPILE to evaluate
response and capacity of shafts subject to laterally loading. For potentially liquefiable soils, a reduced
p-multiplier should be applied to the model P-Y curve of the relevant soil units for evaluating seismic
conditions (Boulanger, et al. 2003).
October 29, 2019 | Page 14 File No. 23325-001-00
TABLE 9. LPILE SOIL PARAMETERS FOR NET POLE FOUNDATIONS
Soil Unit1
Approximate Depth Below
Ground Surface (feet)
Effective Unit
Weight (pcf)
Friction
Angle
(degrees)
Stiffness
Parameter, k
(pci)
P-
Multiplier
Top of Soil
Layer
Bottom of
Soil Layer
Fill 0 6 120 34 110 -
Upper Loose/Soft to
Medium
Dense/Medium Stiff
Alluvium
6 60 57.6 32 50
1 (static)
0.1
(seismic)
Lower Medium
Dense/Medium Stiff
to Dense/Stiff
Alluvium
60 200 67.6 34 120
1 (static)
0.5
(seismic)
Notes:
1 Sand (Reese) Model
2 Refer to Figures 3 and 4
Piles spaced closer than five pile diameters apart will experience group effects that will result in a lower
lateral resistance for trailing rows of piles with respect to leading rows of piles for an equivalent deflection.
We recommend that the lateral load capacity for piles in a pile group spaced less than five pile diameters
apart be reduced in accordance with the factors in Table 6 per AASHTO LRFD Bridge Design Specifications
Section 10.7.2.4.
We recommend that the net pole foundations be designed using a static allowable lateral bearing pressure
of 1,000 psf where the soil adjacent to the foundation consists of undisturbed native soil. For seismic
design conditions, the lateral capacity should be evaluated using the parameters presented in Table 8
above, with the appropriate P-multiplier.
4.5. Outfield and Pavement Area Settlement Mitigation
The outfield and pavement areas are underlain by compressible alluvial soils that will experience long-term
static settlement if subjected to new loads from site fill. The site grading plan indicates that fill ranging up
to 7 feet in thickness (up to 9 feet in local isolated areas) are planned for portions of the outfield and (up
to 3 feet of net fill are planned) to level site grades within the main building footprint. Based on our analysis,
we estimate up to 5½ inches of long-term static settlement resulting from up to 7 feet of new site fill without
mitigation. We anticipate that settlement below the building slab will not be desirable and also understand
that the outfield target structures are settlement sensitive. Options for mitigation include the installation of
deep foundations or ground improvement below settlement sensitive structures. A surcharge and preload
program can also be incorporated into the construction schedule to mitigate static settlements due to new
loads where long term static settlement is not desirable. Our design recommendations for surcharge and
preload are presented below.
4.5.1. Surcharge and Preload Program
The purpose of the preload fill is to induce, prior to final site grading and project completion, a significant
portion of the settlement that will occur when new loads are applied. The program will significantly reduce
post-construction settlement and potential differential settlements due to variability in areal loading and
October 29, 2019 | Page 15 File No. 23325-001-00
thickness of compressible soils. We evaluated preload scenarios for planned fill thicknesses ranging from
3 to 7 feet for preload periods of 9 to 12 weeks. Table 10 summarizes the results of our evaluation.
TABLE 10. LONG-TERM SETTLEMENT (3-, 5- AND 7-FOOT PRELOAD SCENARIOS)
Planned Fill
Thickness
(feet)
Total Long-
Term
Settlement
(inches)
Total Settlement
Remaining after 3-foot
preload
Total Settlement
Remaining after 5-foot
preload
Total Settlement
Remaining after 7-foot
preload
9 weeks 12 weeks 9 weeks 12 weeks 9 weeks 12 weeks
3.0 2.4 0.2 0.1 - - - -
5.0 3.9 2.0 1.9 0.3 0.2 - -
7.0 5.4 3.8 3.7 2.1 2.0 0.4 0.2
Our estimates for the settlement of the preload fill were developed assuming that the preload fill has a total
moist density of at least 120 pcf. If the material used for the preload weighs less than 120 pcf, the height
of the preload fill mound should be adjusted.
Because the site soils have sandy interbeds, the long-term settlement is expected to occur relatively quickly.
Additional surcharge fill can be used to expedite the settlement if needed due to the construction schedule.
The following outlines a summary of our recommendations for grading and constructing the preload area:
■ The preload fill area should extend a distance beyond the extent of the area where settlement is being
mitigated equal to the height of the preload fill.
■ The preload fill toe should be sloped at a 1H:1V (horizontal to vertical) slope. The top of the mound
should be crowned and sloped for drainage.
■ The preload fill should be placed in lifts (not to exceed 12 inches in thickness) and compacted to
95 percent MDD to planned final grade elevation per the project civil engineer. A minimum compaction
level of 85 percent should be achieved for the surcharge fill (if any) above planned final grade elevation.
■ Settlement plates should be installed within the preload fill area. Settlement plate weekly survey
readings should be obtained during construction of preload fill. The first round of survey readings
should be obtained before the first lift of preload fill is placed. After the preload fill has been fully
constructed the settlement plates should also be surveyed on a weekly basis. The settlement
monitoring data will be used to confirm that the preload program is adequately completed.
4.6. Below-Grade Walls
Conventional cast-in-place walls may be necessary for small retaining structures (i.e. retaining or dock-high
walls) located on-site. 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
October 29, 2019 | Page 16 File No. 23325-001-00
distribution), and that 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 8H psf, where H is the height of the wall, should be added to the active/at-rest pressures. For
lateral earth pressure due to surcharge loads, a rectangular earth pressure equals to 0.2q, where q is the
uniform surcharge pressure on top of wall, should be added to the active/at-rest pressures. 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 in accordance with the “Lateral Resistance” discussion
earlier in this report.
The above soil pressures assume that wall drains will be installed to prevent the buildup of hydrostatic
pressure behind the walls, as discussed in the paragraphs below.
If retaining walls, vaults, or recessed target structures are installed without drainage, hydrostatic pressure
behind the walls should be estimated by 62.4Hw psf (triangular distribution), where Hw is the height of the
lowest drainage outlet behind the wall.
4.6.1. Drainage
Positive drainage should be provided behind cast-in-place retaining walls by placing a minimum 2-foot-wide
zone of Gravel Backfill for Walls conforming to Section 9-03.12(2) of the 2018 WSDOT Standard
Specifications. A perforated or slotted 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 Gravel Backfill for Drains
conforming to Section 9-03.12(4) of the 2018 WSDOT Standard Specifications. The Gravel Backfill for
Drains 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.
4.7. Earthwork
4.7.1. Clearing and Site Preparation
All areas to receive fill, structures or pavements should be cleared of vegetation and stripped of topsoil.
Clearing should consist of removal of all trees, brush and other vegetation within the designated clearing
limits. The topsoil materials could be separated and stockpiled for use in areas to be landscaped. Debris
associated with building and site work demolition should be removed from the site, but organic materials
could be chipped/composted and reused in landscape areas, if desired.
We anticipate that the depth of stripping to remove topsoil will generally be about 6 to 12 inches, where
present. Stripping depths may be greater in some areas, particularly where trees and large vegetation have
been removed. Actual stripping depths should be determined based on field observations at the time of
construction. The organic soils can be stockpiled and used later for landscaping purposes or may be spread
over disturbed areas following completion of grading. If spread out, the organic strippings should be in a
layer less than 1-foot-thick, should not be placed on slopes greater than 3H:1V and should be track-rolled
to a uniformly compacted condition. Materials that cannot be used for landscaping or protection of
disturbed areas should be removed from the project site.
October 29, 2019 | Page 17 File No. 23325-001-00
Care must be taken to minimize softening of the subgrade soils during stripping operations. Areas of the
exposed subgrade which become disturbed should be compacted to a firm, non-yielding condition, if
practical, prior to placing any structural fill necessary to achieve design grades. If this is not practical
because the material is too wet, the disturbed material must be aerated and recompacted or excavated
and replaced with structural fill.
4.7.2. Subgrade Preparation
Prior to placing new fills, pavement or hardscape base course materials, and gravel below on-grade floor
slabs, subgrade areas should be proof-rolled to locate soft or pumping soils. Prior to proof rolling, unsuitable
soils should be removed from below building and pavement/hardscape areas. Proof-rolling can be
completed using a piece of heavy tire-mounted equipment such as a loaded dump truck. During wet
weather, the exposed subgrade areas should be probed to determine the extent of soft soils. If soft or
pumping soils are observed, they should be removed and replaced with structural fill.
If deep pockets of soft or pumping soils are encountered outside the building footprint, it may be possible
to limit the depth of overexcavation by placing a woven geotextile fabric such as Mirafi 500X (or similar
material) on the overexcavated subgrade prior to placing structural fill. The geotextile will provide additional
support by bridging over the soft material and will help reduce fines contamination into the structural fill.
This may be performed under pavement areas depending on actual conditions observed during
construction, but it should not occur under the planned building.
After completing the proof-rolling, the subgrade areas should be recompacted to a firm and unyielding
condition, if possible. The achievable degree of compaction will depend on when construction is performed.
If the work is performed during dry weather conditions, we recommend that all subgrade areas be
recompacted to at least 95 percent of the MDD in accordance with the American Society for Testing and
Materials (ASTM) D 1557 test procedure (modified Proctor). If the work is performed during wet weather
conditions, it may not be possible to recompact the subgrade to 95 percent of the MDD. In this case, we
recommend that the subgrade be compacted to the extent possible without causing undue heaving or
pumping of the subgrade soils.
Subgrade disturbance or deterioration could occur if the subgrade is wet and cannot be dried. If the
subgrade deteriorates during proof rolling or compaction, it may become necessary to modify the proof
rolling or compaction criteria or methods.
4.7.3. Subgrade Protection
Site soils may contain significant fines content (silt/clay) and will be highly sensitive and susceptible to
moisture and equipment loads. The contractor should take necessary measures to prevent site subgrade
soils from becoming disturbed or unstable. Construction traffic during the wet season should be restricted
to specific areas of the site, preferably areas that are surfaced with crushed rock materials not susceptible
to wet weather disturbance.
4.7.4. Structural Fill
All fill, whether on-site soils or imported fill for support of foundations, floor slab areas, pavement areas
and as backfill for retaining walls or in utility trenches should meet the criteria for structural fill presented
below. Structural fill soils should be free of organic matter, debris, man-made contaminants and other
October 29, 2019 | Page 18 File No. 23325-001-00
deleterious materials, with no individual particles larger than 4 inches in greatest dimension. The suitability
of soil for use as structural fill depends on its gradation and moisture content.
4.7.4.1. Fill Criteria
Recommended structural fill material quality varies depending upon its use as described below:
■ Structural fill to construct pavement areas, to place below foundations and slabs, to construct
embankments, to backfill retaining walls and utility trenches, and to place against foundations
should consist of gravel borrow as described in Section 9-03.14(1) of the 2018 WSDOT Standard
Specifications, with the additional restriction that the fines content be limited to no more than
5 percent, especially if the work occurs in wet weather or during the wet season (October through May).
However, if earthwork occurs during the normally dry months (June through September) on-site sandy
soils that are properly moisture conditioned, that are free of concrete rubble and other debris, and that
can be properly compacted may be used as structural fill in these areas. It may be possible to use
on-site sandy soils during wet weather for areas requiring only 90 percent compaction provided the
earthwork contractor implements good wet weather techniques and drier soils are used; however, we
recommend gravel borrow be specified for planning/bidding purposes.
■ Structural fill placed in the minimum 2-foot-wide drainage zone behind retaining walls consist of Gravel
Backfill for Walls conforming to Section 9-03.12(2) of the 2018 WSDOT Standard Specifications.
■ Structural fill placed around wall and footing drains should consist of Gravel Backfill for Drains
conforming to Section 9-03.12(4) of the 2018 WSDOT Standard Specifications.
■ Structural fill placed as capillary break material below slab-on-grade floors should consist of clean
crushed rock and meet the gradation requirements of Mineral Aggregate Type 22 (¾-inch crushed
gravel), City of Seattle Standard Specification 9-03.16. The capillary break may be eliminated if ground
improvement methods are used to support the buildings and a 2-foot thick crushed rock layer is placed
below the slabs.
■ Structural fill placed as crushed surfacing base course below pavements should conform to
Section 9-03.9(3) of the 2018 WSDOT Standard Specifications.
We recommend that the suitability of structural fill soil from proposed borrow sources be evaluated by a
representative of our firm before the earthwork contractor begins transporting the soil to the site.
4.7.4.2. Reuse of On-site Soils
On-site silty soils located within the upper few feet across the site will be difficult to reuse in the wet season
or wet weather conditions. The silty soils should not be reused under the planned structures. The on-site
sandy soils located above the water table may be used as structural fill in all areas during dry weather
conditions (typically June through September), provided the material is properly moisture conditioned.
Imported Gravel Borrow may be required for use as structural fill during wet weather conditions and during
the wet season (typically October through May) if the on-site sandy soils cannot be properly moisture
conditioned and compacted. The existing sandy soils are expected to be suitable for structural fill in areas
requiring compaction to at least 95 percent of MDD (per ASTM D 1557), provided the work is accomplished
during the normally dry season (June through September) and that the soil can be properly moisture
conditioned to within 2 percent of the optimum moisture content. Concrete rubble and other debris must
be removed from the existing fill soils before they can be reused as structural fill. Imported structural fill
consisting of sand and gravel (WSDOT Gravel Borrow) should be planned under all building floor slabs and
October 29, 2019 | Page 19 File No. 23325-001-00
foundation elements and as wall backfill, especially if construction occurs during wet weather or the wet
season (typically October through May).
The contractor should plan to cover and maintain all stockpiles of on-site soil with plastic sheeting if it will
be used as structural fill. The reuse of on-site soils is highly dependent on the skill of the contractor and
the weather conditions, and we will work with the design team and contractor to maximize the reuse of
on-site soils during the wet and dry seasons; however, imported gravel borrow should be planned for and
specified for wet weather construction.
4.7.4.3. 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 12 inches in thickness if using heavy compactors and 6 inches if using
hand operated compaction equipment. The actual lift thickness will be dependent on the structural fill
material used and the type and size of compaction equipment. Each lift should be moisture conditioned to
within 2 percent of the optimum moisture content and compacted to the specified density before placing
subsequent lifts. Structural fill should be compacted to the following criteria:
■ All fill placed under the proposed structures should be placed as structural fill compacted to at least
95 percent of the MDD estimated using the ASTM D 1557 test method.
■ Structural fill placed against foundations should be compacted to at least 95 percent of the MDD.
■ Structural fill placed behind below-grade walls should be compacted to between 90 to 92 percent of
the MDD estimated using ASTM D 1557. Care should be taken when compacting fill near the face of
below-grade walls to avoid over-compaction and hence overstressing the walls. Hand operated
compactors should be used within 5 feet behind the wall. The upper 2 feet of fill below floor slab
subgrade level should also be compacted to at least 95 percent of the MDD. The contractor should
keep all heavy construction equipment away from the top of retaining walls a horizontal distance equal
to half the height of the wall, or at least 5 feet, whichever is greater.
■ Structural fill in new pavement and hardscape areas, including utility trench backfill, should be
compacted to at least 90 percent of the MDD, except that the upper 2 feet of fill below final subgrade
level should be compacted to at least 95 percent of the MDD.
■ Structural fill placed as crushed surfacing base course below pavements should be compacted to
95 percent of the MDD.
■ Non-structural fill, such as fill placed in landscape areas, should be compacted to at least 90 percent
of the MDD.
An adequate number of in-place moisture and density tests should be performed during the placement and
compaction of structural fill to evaluate whether the specified degree of compaction is being achieved.
4.7.4.4. Weather Considerations
Disturbance of near surface soils should be expected, especially if earthwork is completed during periods
of wet weather. During dry weather, the soils will: (1) be less susceptible to disturbance; (2) provide better
support for construction equipment; and (3) be more likely to meet the required compaction criteria.
October 29, 2019 | Page 20 File No. 23325-001-00
The wet weather season generally begins in October and continues through May in western Washington;
however, periods of wet weather may occur during any month of the year. For earthwork activities during
wet weather, we recommend the following steps be taken:
■ 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 so that areas of ponded water do not
develop. Measures should be taken by the contractor to prevent surface water from collecting in
excavations and trenches. Measures should be implemented to remove surface water from the
work area.
■ Surface water must not be directed toward slopes and we recommend that storm water drainage
ditches be constructed where needed along the crest of slopes to prevent uncontrolled surface water
runoff.
■ Earthwork activities should not take place during periods of moderate to heavy precipitation.
■ Slopes with exposed soils should be covered with plastic sheeting.
■ The contractor should take necessary measures to prevent on-site soils and soils to be used as fill from
becoming wet or unstable. These measures may include the use of plastic sheeting, sumps with pumps,
and grading. 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 help reduce the
extent that these soils become wet or unstable.
■ The contractor should cover all soil stockpiles that will be used as structural fill with plastic sheeting.
■ Construction traffic should be restricted to specific areas of the site, preferably areas that are surfaced
with the existing asphalt or working pad 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 practical.
Routing of equipment on the existing fill and native silty soils during the wet weather months will be difficult
and the subgrade will likely become highly disturbed and rutted. In addition, a significant amount of mud
can be produced by routing equipment directly on these soils in wet weather. Therefore, to protect the
subgrade soils and to provide an adequate wet weather working surface for the contractor’s equipment
and labor, we recommend that the contractor protect exposed subgrade soils with crushed rock or
asphalt-treated base (ATB), as necessary.
4.7.5. Temporary Cut Slopes
For planning purposes, temporary unsupported cut slopes more than 4 feet high may be inclined at 1½H:1V
in the fill and native soils. These inclinations may need to be flattened by the contractor if significant
caving/sloughing or groundwater seepage occurs. For open cuts at the site, we recommend that:
■ No traffic, construction equipment, stockpiles, or building supplies be allowed at the top of cut slopes
within a distance of at least 5 feet from the top of the cut;
■ The excavation not encroach on a 1H:1V influence line projected down from the edges of nearby or
planned foundation elements;
October 29, 2019 | Page 21 File No. 23325-001-00
■ Exposed soil along the slope be protected from surface erosion using waterproof tarps or plastic
sheeting or flash coating with shotcrete;
■ 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 excavation; and
■ The general condition of the slopes be observed periodically by GeoEngineers 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. Shoring and temporary
slopes must conform to applicable local, state and federal safety regulations.
4.7.6. Permanent Cut and Fill Slopes
We recommend that permanent cut or fill slopes be constructed at inclinations of 2H:1V or flatter and be
blended into existing slopes with smooth transitions. To achieve uniform compaction, we recommend that
fill slopes be overbuilt slightly and subsequently cut back to expose well compacted fill.
To reduce erosion, newly constructed slopes and disturbed existing 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 necessitate localized repairs and reseeding. Temporary
covering, such as clear heavy plastic sheeting, or erosion control blankets (such as American Excelsior
Curlex 1 or North American Green SC150BN) could be used to protect the slopes during periods of rainfall.
4.7.7. Erosion and Sediment Control
In our opinion, the erosion potential of the on-site soils is low to moderate. Construction activities including
stripping and grading will expose soils to the erosional effects of wind and water. The amount and potential
impacts of erosion are partly related to the time of year that construction occurs. Wet weather construction
will increase the amount and extent of erosion and potential sedimentation.
Erosion and sedimentation control measures may be implemented by using a combination of interceptor
swales, straw bale barriers, silt fences and straw mulch for temporary erosion protection of exposed soils.
All disturbed areas should be finish graded and seeded as soon as practicable to reduce the risk of erosion.
4.7.8. Utility Trenches
Trench excavation, pipe bedding and trench backfilling should be completed using the general procedures
described in the 2018 WSDOT Standard Specifications, or City of Renton requirements, or as specified by
the project civil engineer.
Utility trench backfill should consist of structural fill and should be placed in lifts of 12 inches or less (loose
thickness) when using heavy compaction equipment, and 6 inches or less when using hand compaction
equipment, such that adequate compaction can be achieved throughout the lift. Each lift must be
compacted prior to placing the subsequent lift. Prior to compaction, the backfill should be moisture
October 29, 2019 | Page 22 File No. 23325-001-00
conditioned to within 2 percent of the optimum moisture content. The backfill should be compacted in
accordance with the criteria discussed above.
4.8. Pavement Recommendations
4.8.1. Subgrade Preparation
We recommend the subgrade soils in new pavement areas be prepared and evaluated as described in the
“Earthwork” section of this report. Where existing fill is present, we recommend placing a 6-inch-thick
imported granular subbase layer meeting the requirements of Gravel Borrow (Section 9-03.14(1) of the
2018 WSDOT Standard Specifications) below the pavement sections described below. If the subgrade soils
are excessively loose or soft, it may be necessary to excavate localized areas and replace them with
additional gravel borrow or gravel base material. Pavement subgrade conditions should be observed and
proof-rolled during construction and prior to placing the subbase materials to evaluate the presence of
unsuitable subgrade soils and the need for over-excavation and placement of a geotextile separator.
The following pavement recommendations are for standard hot-mix asphalt (HMA) pavement designs. We
understand that permeable pavement may be considered at the site. We can provide permeable pavement
recommendations upon request.
4.8.2. New Hot-Mix Asphalt Pavement
In light-duty pavement areas (e.g., pedestrian access or passenger car parking), we recommend a
pavement section consisting of at least a 3-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 surfacing base course
(CSBC) per WSDOT Section 9-03.9(3).
In medium-duty pavement areas (e.g., drive aisles), 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 CSBC per
WSDOT Section 9-03.9(3).
The crushed surfacing base course in both light-duty and medium-duty areas should be compacted to at
least 95 percent of the MDD (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 and typical traffic data provided
by ARCO Murray. Thicker asphalt sections may be needed based on the actual projected traffic data, bus
or truck loads, and intended use.
4.8.3. Portland Cement Concrete Pavement
Portland cement concrete (PCC) sections may be considered for loading dock aprons, trash dumpster areas
and where other concentrated heavy loads may occur. For heavy-duty (e.g., service trucks, fire trucks, etc.)
concrete paving, we recommend 8 inches of PCC overlying 6 inches of CSBC per WSDOT Section 9-03.9(3).
The concrete thickness should be increased by the thickness of the reinforcing steel, if steel reinforcement
is used.
October 29, 2019 | Page 23 File No. 23325-001-00
The crushed surface base course in both light duty and heavy-duty areas should be compacted to at least
95 percent of the MDD (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.
We recommend PCC pavements incorporate construction joints and/or crack control joints spaced
maximum distances of 12 feet apart, center-to-center, in both the longitudinal and transverse directions.
Crack control joints may be created by placing an insert or groove into the fresh concrete surface during
finishing, or by sawcutting the concrete after it has initially set-up. We recommend the depth of the crack
control joints be approximately one-fourth the thickness of the concrete. We also recommend that the
project team consider sealing crack control joints with an appropriate sealant to help restrict water
infiltration into the joints.
4.9. Construction Dewatering
Static groundwater was observed in the borings at the time of exploration, as described in the “Groundwater
Conditions” section of this report. Therefore, shallow excavations for utility trenches, underground vaults
and elevator shafts may encounter groundwater.
Dewatering during construction of these areas and other excavations on site may be required. Based on
the soil conditions and our experience in the area, we expect that groundwater in excavations less than
about 5 feet below existing grades can be controlled by open pumping using sump pumps. For excavations
extending deeper and below the static ground water table dewatering using well points or deep wells will
be necessary. We recommend that the contractor be required to submit a proposed dewatering system
design and plan layout to the project team for review and comment prior to beginning construction.
The level of effort required for dewatering will depend on the time of year during which construction is
accomplished. Less seepage into the work areas and a lower water table should be expected if construction
is accomplished in the late summer or early fall months, and correspondingly, more seepage and a higher
water table should be expected during the wetter periods of the year and into the spring months. We
recommend that earthwork activities be completed in the late summer or early fall months when
precipitation is typically at its lowest.
4.10. Infiltration Considerations
The feasibility of infiltration was assessed at the site through review of near surface soil conditions and
groundwater levels. Due to a relatively shallow groundwater table (as shallow as 4 feet based on
observations during drilling) and the presence of low permeability silt soils near the ground surface, we
conclude that the use of large scale infiltration facilities is not feasible at this site. GeoEngineers can
provide design infiltration rates for on-site best management practices (BMPs) such as permeable
pavement or rain gardens, if required.
4.11. Recommended Additional Geotechnical Services
Throughout this report, recommendations are provided where we consider additional geotechnical services
to be appropriate. These additional services are summarized below:
■ GeoEngineers can prepare construction drawings and specifications for ground improvement (such as
stone columns or rigid inclusions) for the project, if requested.
October 29, 2019 | Page 24 File No. 23325-001-00
■ GeoEngineers should be retained to review the project plans and specifications when complete to
confirm that our design recommendations have been implemented as intended.
■ During construction, GeoEngineers should observe stripping and grading; observe and evaluate
installation of ground improvement elements or deep foundations; observe and evaluate the suitability
of foundation, wall and floor slab subgrades; observe removal of unsuitable fill and debris/rubble from
below the building and parking garage footprints and hardscape areas; observe and test structural fill
including wall and utility trench backfill; observe installation of subsurface drainage measures and
infiltration facilities; evaluate the suitability of pavement subgrades and other appurtenant structures,
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, to provide recommendations for design changes should the conditions
revealed during the work differ from those anticipated, to evaluate whether or not earthwork and
foundation installation activities are completed in accordance with our recommendations, and other
reasons described in Appendix D, Report Limitations and Guidelines for Use.
5.0 LIMITATIONS
We have prepared this report for the exclusive use of ARCO Murray Design Build and their authorized agents
for the Logan Avenue North and North 8th Street development 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 for additional information pertaining to use of this report.
6.0 REFERENCES
Al Atik, L. and N. Abrahamson (2010). “An Improved Method for Nonstationary Spectral Matching,”
Earthquake Spectra, Vol. 26, No. 3, pp. 601-617.
ASCE 7-10, 2010. “Minimum Design Loads for Buildings and Other Structures,” American Society of Civil
Engineers.
ASTM D-1557, 2012. “Standard Testing Method for Laboratory Compaction Characteristics of Soil Using
Modified Effort,” ASTM International.
Atkinson, G.M., Boore, D.M., 2003. “Empirical ground-motion relations for subduction-zone earthquakes
and their application to Cascadia and other regions,” Bulletin of the Seismological Society of
America, v. 93, n. 4, p. 1703-1729.
October 29, 2019 | Page 25 File No. 23325-001-00
Boore, D.M. and G.M. Atkinson, 2008. “Ground Motion Prediction Equations for the Average Horizontal
Component of PGA, PGV, and 5% Damped PSA at Spectral Periods between 0.01s and 10.0 s.”
Earthquake Spectra 24, 99-138.
R. W. Boulanger, B. L. Kutter, S. J. Brandenberg, P. Singh, D. Chang, September, 2003. “Pile Foundations
in Liquefied and Laterllay Spreading Ground during Earthquakes: Centrifuge Experiments &
Analyses.” Center for Geotechnical Modeling, Repot No. UCD/CGM-03/01.
Campbell, K.W. and Y. Bozorgnia, 2008. “NGA Ground Motion Model for the Geometric Mean Horizontal
Component of PGA, PGV, PGD and 5% Damped Linear Elastic Response Spectra for Periods
Ranging from 0.01 to 10s.” Earthquake Spectra, Vol. 24, No. 1, 139-171.
Chiou, B.S.J. and R.R. Youngs, 2008. “An NGA Model for the Average Horizontal Component of Peak Ground
Motion and Response Spectra.” Earthquake Spectra, Vol. 24, No. 1, 173-215.
City of Seattle, 2017, “Standard Specifications for Road, Bridge and Municipal Construction.”
Darendeli, M., 2001. “Development of a new family of normalized modulus reduction and material damping
curves.” Ph.D. Thesis, Dept. of Civil Eng., Univ. of Texas, Austin.
Cetin, K.O., H.T. Bulge, J. Wu, A.M. Kammerer, and R.B. Seed 2009, “Probabilistic Model for the Assessment
of Cyclically Induced Reconsolidation (Volumetric) Settlement.” Journal of Geotechnical and
Geoenvironmental Engineering, 135(3), pp. 387-398.
Fouad, L. and E.M. Rathje (2012). “RSPMatch09” http://nees.org/resources/rpsmatch09.
Idriss, I. M., and R. W. Boulanger 2008. “Soil Liquefaction during Earthquakes.” Earthquake Engineering
Research Institute MNO-12.
International Code Council, 2015, “International Building Code.”
Ishihara, K., and Yoshimine, M., “Evaluation of Settlements in Sand Deposits Following Liquefaction During
Earthquakes,” Soils and Foundations, 32(1), 1992, pp. 173-188.
Petersen, Mark D., Frankel, Arthur D., Harmsen, Stephen C., Mueller, Charles S., Haller, Kathleen M.,
Wheeler, Russell L., Wesson, Robert L., Zeng, Yuehua, Boyd, Oliver S., Perkins, David M., Luco,
Nicolas, Field, Edward H., Wills, Chris J., and Rukstales, Kenneth S. (2008). Documentation for the
2008 Update of the United States National Seismic Hazard Maps: United States Geological Survey
Open-File Report 2008-1128.
Shahi, S.K. and J.K. Baker (2014). “NGA-West2 Models for Ground-Motion Directionality.” Earthquake
Spectra, Vol. 30, No. 3, pp. 1285-1300.
Tokimatsu K., Seed H.B., 1987. “Evaluation of settlements in sands due to earthquake shaking,” Journal
of Geotechnical Engineering, 1987, vol. 113, pp. 861-878.
USGS Unified Hazard Tool (Version Dynamic: Conterminous U.S. 2008).
October 29, 2019 | Page 26 File No. 23325-001-00
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 Transportation (WSDOT), 2018. “Standard Specifications for Road,
Bridge, and Municipal Construction.”
Wong, Ivan; Sparks, Andrew; Thomas, Patricia; Nemser, Eliza, 2003, Evaluation of near-surface site
amplification in the Seattle, Washington, metropolitan area—Final technical report: Seismic
Hazards Group, URS Corporation [under contract to] U.S. Geological Survey, 1 v.
Youd, T. L. and Idriss, I. M. 2001. “Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER
and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils,” Journal of
Geotechnical and Geoenvironmental Engineering, Vol. 127, No. 4, April 2001, pp. 298-313.
Youngs, R.; Chiou, S-J.; Silva, W.; Humphrey, J. (1997). Strong ground motion attenuation relationships for
subduction zone earthquakes. Seismological Research Letters 68. 58-73.
Zhao J.X., Zhang, J., Asano, A., Ohno, Y., Oouchi, T., Takahashi, T., Ogawa, H., Irikura, K., Thio, H., Somerville,
P., Fukushima, Y., and Fukushima, Y., 2006 Attenuation relations of strong ground motion in Japan
using site classification based on predominant period: Bulletin of the Seismological Society of
America, v. 96, p. 898–913.
FIGURES
µ
SITE
Vicinity Map
Figure 1
Logan Avenue N / N 8th Street Development
Renton, Washington
2,000 2,0000
Feet
Data Source: Mapbox Open Street Map, 2018
Notes:1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended toassist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and contentof electronic files. The master file is stored by GeoEngineers,Inc. and will serve as the official record of this communication.
Projection: NAD 1983 UTM Zone 10N
P:\23\23325001\GIS\MXD\2332500100_F01_VicinityMap.mxd Date Exported: 09/10/19 by glohrmeyer
P
P
PP 28
28
303030303030
30
3030
30
323230303030 3
2
3
0
282830303030302828
2
8282
8
30
303029
31
29
29
29
292929
29
29 29
292929 2929
29
2929
GENERATORXFMR
DUMPSTERENCLOSURE
PROPOSED BUILDING
HGI & HOME2135,803 S.F.
5 STORY, 228 ROOMS
77 PARKING SPACESAB-1
CPT-1
B-1
OB-1
OB-6
B-2
OB-2
OB-3
OB-4
PB-1
OB-5
OB-7
AB-3
GEI-2
GEI-1
CPT-2
CPT-3
CPT-4
CPT-5
CPT-6
N 8th St.Park Ave. NLogan Ave. NB'B
A A'
B-1-19
B-2-19
B-3-19
GEI-3-19
GEI-4-19
GEI-3-19a
B-4-19
C'CD'D
GEI-2-19
GEI-1-19
GEI-5-19
AB-2
Figure 2
Logan Avenue N / N 8th Street Development
Renton, Washington
Site Plan
W E
N
S
P:\23\23325001\CAD\00\GeoTech\23325000100_F02-06_Site Plan and Cross-Sections.dwg TAB:F02 Date Exported: 09/03/19 - 22:18 by syiLegend
Property Boundary
Boring by GeoEngineers, 2018
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: Site Survey by Axis Survey & Mapping, dated 04/23/18.
Projection: WA State Plane, North Zone, NAD83, US Foot
Feet
0100 100
AB-1, B-1, GEI-1, OB-1, PB-1
CPT-1 Cone Penetration Test by GeoEngineers, 2018
Cross-Section Location
A A'
B-1-19 & GEI-1-19 Boring Completed by GeoEngineers, 2019
GEI-3-19a Monitoring Well Completed by GeoEngineers, 2019
Elevation (Feet)Elevation (Feet)Distance (Feet)
-60
-40
-20
0
20
40
-60
-40
-20
0
20
40
0 80 160 240 320 400 480 560 640 720 800 880 960960OB-6(Offset 81 ft)OB-1(Offset 36 ft)PB-1(Offset 33 ft)OB-5(Offset 74 ft)CPT-1(Offset 26 ft)CPT-6(Offset 14 ft)A
(West)
A'
(East)
Fill
Upper Loose/Soft to
Medium Dense/Medium
Stiff Sands and Silts
(Alluvium)
Lower Medium Dense to Dense/Stiff
Gravels, Sand and Silt (Alluvium)AB-1(Offset 15 ft)B-4-19(Offset 12 ft)QT (tsf)0 500
QT (tsf)
0 500
ACGPSMSP-SM
ML
SP-SMSM
24
2
11
7
TSSM
GW-GM
SMML
SM
ML
SM
25
8
3
6
3
3
4
TSSM
SMSM
SM
ML
ML
ML
SM
SM
13
2
2
3
4
5
19
14
TS
SM
SM
ML
SP-SM
OL
PT
SM
SP-SM
MLPT
14
5
4
3
2
8
21
7
9
Grass
SM
SMML
SP-SM
SM
SP-SM
PT
SP-SM
8
6
8
14
8
4
14
Loose/Medium Stiff Sand and Silt with Thin Layers of Stiff Peat (Alluvium)
Lower Medium Dense to Dense/Stiff Gravels, Sand and Silt (Alluvium)
ACCRSM
SM
ML
SM
ML
SM
ML
MH
SM
GP
MH
SM
SP-SM
SM
28
5
3
4
17
17
2
5
4
6
14
31
22
23
12
31
20
9
26
Figure 3
Logan Avenue N / N 8th Street Development
Renton, Washington
Cross-Section A-A'P:\23\23325001\CAD\00\GeoTech\23325000100_F02-06_Site Plan and Cross-Sections.dwg TAB:F03 Date Exported: 09/11/19 - 15:26 by syiLegend
Notes:
1.The subsurface conditions shown are based on interpolation
between widely spaced explorations and should be considered
approximate; actual subsurface conditions may vary from those
shown.
2.This figure is for informational purposes only. It is intended to
assist in the identification of features discussed in a related
document. Data were compiled from sources as listed in this
figure. The data sources do not guarantee these data are
accurate or complete. There may have been updates to the
data since the publication of this figure. This figure is a copy of
a master document. The hard copy is stored by GeoEngineers,
Inc. and will serve as the official document of record.
Datum: NAVD 88, unless otherwise noted.
SM
20
Boring
Inferred Soil Contact
Soil Classification
Blow Count
Legend
EXPLORATION ID(Offset Distance)Fill
Horizontal Scale in Feet
080 80
Vertical Scale in Feet
020 20
Vertical Exaggeration: 4X
QT (tsf)
0 500EXPLORATION ID(Offset Distance)Cone Penetration Test
Tip Resistance
Upper Loose/Soft to Medium Dense/Medium
Stiff Sands and Silts (Alluvium)
Lower Medium Dense to Dense/Stiff
Gravels, Sand and Silt (Alluvium)
Loose/Medium Stiff Sand and Silt with
Thin Layers of Stiff Peat (Alluvium)
Elevation (Feet)Elevation (Feet)Distance (Feet)
-60
-40
-20
0
20
40
-60
-40
-20
0
20
40
0 80 160 240 320 400 480 560 640 720 800 880 960 1040 1100
B
(West)
B'
(East)B-2(Offset 11 ft)OB-2(Offset 25 ft)OB-3(Offset 35 ft)OB-4(Offset 75 ft)OB-7(Offset 106 ft)GEI-2(Offset 63 ft)CPT-2(Offset 90 ft)CPT-3(Offset 56 ft)CPT-5(Offset 50 ft)B-1-19(Offset 60 ft)B-2-19(Offset 21 ft)GEI-3-19a(Offset 80 ft)GEI-1-19(Offset 0 ft)GEI-3-19(Offset 82 ft)GEI-4-19(Offset 34 ft)QT (tsf)
0 500
QT (tsf)
0 500
QT (tsf)
0 500
TS
SM
SM
ML
SM
OH
SPSM
SP-SM
SM
MH
SM
SP
24
2
2
2
33
23
6
4
8
TSSM
SP-SMMLML
SM
PT
SM
ML
SM
SP-SM
5
3
4
2
21
5
10
GrassSM
SW-SM
SM
PT
SP-SM
ML
SP-SM
19
9
2
2
9
2
13
TSSM
SP
MHSMML
SM
SP-SM
ML
SP
26
8
6
14
2
11
12
5
TSSM
SMMLSM
MH
SM
MH
ML
SP
MLPT
19
5
1/12"
3
2
3
4
TSSM
SP-SM
MLMLMLSM
18
2
1/12"
5
Fill
Upper Loose/Soft to
Medium Dense/Medium
Stiff Sands and Silts
(Alluvium)
Lower Medium Dense to Dense/Stiff
Gravels, Sand and Silt (Alluvium)
Loose/Medium Stiff Sand and Silt with Thin Layers of Stiff Peat (Alluvium)
Lower Medium Dense to Dense/Stiff Gravels, Sand and Silt (Alluvium)
AC
SM
ML
SP-SM
ML
PT
ML
SM
ML
PT
MH
SM
PT
SM
ML
SM
SP-SM
ML
SM
SP-SM
4
4
1
10
1
2
8
4
10
23
16
17
36
66
80
5
30
37
TS
SM
ML
SM
SP-SM
ML
SM
ML
PT
ML
PT
ML
SM
SP-SM
ML
SP-SM
SM
58
25
2
3
9
7
24
6
6
6
7
4
44
21
87
7
56
29
TS
SM
ML
SM
ML
SM
ML
SM
ML
SM
PT
SM
PT
SP-SM
PT
ML
SM
MLSM
23
10
1
2
3
14
12
18
9
20
17
7
9
35
23
11
17
33
TS
SM
SM
SP-SM
SM
PT
ML
ML
SP-SM
ML
SM
SP-SM
SM
ML
SM
ML
SM
SM
42
8
7
7
6
6
12
14
13
11
21
4
6
41
14
13
18
37
TS
SM
ML
SM
ML
SP-SM
ML
PT
SM
PT
ML
PT
ML
SP-SM
PT
ML
SP-SM
45
4
11
4
1
6
4
13
4
9
7
6
7
22
32
17
10
30
Figure 4
Logan Avenue N / N 8th Street Development
Renton, Washington
Cross-Section B-B'P:\23\23325001\CAD\00\GeoTech\23325000100_F02-06_Site Plan and Cross-Sections.dwg TAB:F04 Date Exported: 09/11/19 - 15:26 by syiNotes:
1.The subsurface conditions shown are based on interpolation between
widely spaced explorations and should be considered approximate; actual
subsurface conditions may vary from those shown.
2.This figure is for informational purposes only. It is intended to assist in the
identification of features discussed in a related document. Data were
compiled from sources as listed in this figure. The data sources do not
guarantee these data are accurate or complete. There may have been
updates to the data since the publication of this figure. This figure is a
copy of a master document. The hard copy is stored by GeoEngineers, Inc.
and will serve as the official document of record.
Datum: NAVD 88, unless otherwise noted.
Legend
SM
20
Boring
Inferred Soil Contact
Soil Classification
Blow Count
Legend
EXPLORATION ID(Offset Distance)Horizontal Scale in Feet
080 80
Vertical Scale in Feet
020 20
Vertical Exaggeration: 4X
QT (tsf)
0 500EXPLORATION ID(Offset Distance)Cone Penetration Test
Tip Resistance
Fill
Upper Loose/Soft to Medium Dense/Medium
Stiff Sands and Silts (Alluvium)
Lower Medium Dense to Dense/Stiff
Gravels, Sand and Silt (Alluvium)
Loose/Medium Stiff Sand and Silt with
Thin Layers of Stiff Peat (Alluvium)
Elevation (Feet)Elevation (Feet)Distance (Feet)
-60
-40
-20
0
20
40
-60
-40
-20
0
20
40
0 60 120 180 240 300 360 420 480 540
C
(North)
C'
(South)
TSMLSMSMMLSMMLSM
SP-SM
ML
SM
ML
ML
SP-SM
SP-SM
PT
ML
PT
SM
SM
16
2
2
10
12
23
3
6
7
4
6
6
44
25
TS
SM
SM
ML
SM
OHSPSM
SP-SM
SM
MH
SM
SP
24
2
2
2
33
23
6
4
8 B-2(Offset 58 ft)B-1(Offset 28 ft)B-4-19(Offset 27 ft)B-1-19(Offset 40 ft)B-2-19(Offset 9 ft)B-3-19(Offset 12 ft)CPT-2(Offset 112 ft)CPT-1(Offset 84 ft)QT (tsf)
0 500 QT (tsf)
0 500 AB-2(Offset 1 ft)Grass
SM
SP-SMPTMLSM
33
22
6
19
Fill
Upper
Loose/Soft to
Medium
Dense/Medium
Stiff Sands and
Silts (Alluvium)
Lower Medium Dense
to Dense/Stiff Gravels,
Sand and Silt (Alluvium)
Loose/Med
i
u
m
S
t
i
f
f
S
a
n
d
a
n
d
S
i
l
t
w
i
t
h
Thin Layers
o
f
S
t
i
f
f
P
e
a
t
(
A
l
l
u
v
i
u
m
)
?
?
Building North
ACCRSM
SM
ML
SM
ML
SM
ML
MH
SM
GP
MH
SM
SP-SM
SM
28
5
3
4
17
17
2
5
4
6
14
31
22
23
12
31
20
9
26
AC
SM
ML
SP-SM
ML
PT
ML
SM
ML
PT
MH
SM
PT
SM
ML
SM
SP-SM
ML
SM
SP-SM
4
4
1
10
1
2
8
4
10
23
16
17
36
66
80
5
30
37
TS
SM
ML
SM
SP-SM
ML
SM
ML
PT
ML
PT
ML
SM
SP-SM
ML
SP-SM
SM
58
25
2
3
9
7
24
6
6
6
7
4
44
21
87
7
56
29
TS
SM
ML
SP-SM
SM
ML
SM
ML
SM
ML
SM
ML
SM
PT
SP-SM
SP-SM
ML
SP-SM
ML
26
27
6
8
24
20
22
2
18
29
10
24
40
34
29
25
35
15
Building South
Figure 5
Logan Avenue N / N 8th Street Development
Renton, Washington
Cross-Section C-C'P:\23\23325001\CAD\00\GeoTech\23325000100_F02-06_Site Plan and Cross-Sections.dwg TAB:F05 Date Exported: 09/11/19 - 15:27 by syiNotes:
1.The subsurface conditions shown are based on interpolation between
widely spaced explorations and should be considered approximate; actual
subsurface conditions may vary from those shown.
2.This figure is for informational purposes only. It is intended to assist in the
identification of features discussed in a related document. Data were
compiled from sources as listed in this figure. The data sources do not
guarantee these data are accurate or complete. There may have been
updates to the data since the publication of this figure. This figure is a
copy of a master document. The hard copy is stored by GeoEngineers, Inc.
and will serve as the official document of record.
Datum: NAVD 88, unless otherwise noted.
Legend
SM
20
Boring
Inferred Soil Contact
Soil Classification
Blow Count
Legend
EXPLORATION ID(Offset Distance)Horizontal Scale in Feet
060 60
Vertical Scale in Feet
020 20
Vertical Exaggeration: 3X
QT (tsf)
0 500EXPLORATION ID(Offset Distance)Cone Penetration Test
Tip Resistance
Fill
Upper Loose/Soft to Medium Dense/Medium
Stiff Sands and Silts (Alluvium)
Lower Medium Dense to Dense/Stiff
Gravels, Sand and Silt (Alluvium)
Loose/Medium Stiff Sand and Silt with
Thin Layers of Stiff Peat (Alluvium)
Elevation (Feet)Elevation (Feet)Distance (Feet)
-60
-40
-20
0
20
40
-60
-40
-20
0
20
40
0 60 120 180 240 300 360 420 450
D
(West)
D'
(East)
TSGMSMMLSP
ML
SM
ML
SP-SM
ML
SP
18
6
13
5
8
2
16 GEI-1(Offset 8 ft)GEI-2-19(Offset 0 ft)GEI-5-19(Offset 7 ft)Fill
Upper Loose/Soft to
Medium Dense/Medium
Stiff Sands and Silts
(Alluvium)
Lower Medium Dense to Dense/Stiff
Gravels, Sand and Silt (Alluvium)
Loose/Medium Stiff Sand and Silt with
Thin Layers of Stiff Peat (Alluvium)
Lower Medium Dense to Dense/Stiff Gravels, Sand and Silt (Alluvium)
TSSMMLSMML
SM
ML
SP-SM
PT
MLPTSM
ML
SP-SM
PT
ML
SM
18
9
14
18
4
2
17
4
8
5
4
4
7
32
19
12
15
23
TS
SM
ML
SM
ML
SM
ML
PT
SM
SP-SM
ML
SP-SM
ML
SP-SM
PT
ML
SMMLSM
28
7
6
4
4
4
24
5
6
19
10
5
8
44
19
12
20
25
Figure 6
Logan Avenue N / N 8th Street Development
Renton, Washington
Cross-Section D-D'P:\23\23325001\CAD\00\GeoTech\23325000100_F02-06_Site Plan and Cross-Sections.dwg TAB:F06 Date Exported: 09/11/19 - 15:27 by syiNotes:
1.The subsurface conditions shown are based on interpolation between
widely spaced explorations and should be considered approximate; actual
subsurface conditions may vary from those shown.
2.This figure is for informational purposes only. It is intended to assist in the
identification of features discussed in a related document. Data were
compiled from sources as listed in this figure. The data sources do not
guarantee these data are accurate or complete. There may have been
updates to the data since the publication of this figure. This figure is a
copy of a master document. The hard copy is stored by GeoEngineers, Inc.
and will serve as the official document of record.
Datum: NAVD 88, unless otherwise noted.
Legend
SM
20
Boring
Inferred Soil Contact
Soil Classification
Blow Count
Legend
EXPLORATION ID(Offset Distance)Horizontal Scale in Feet
060 60
Vertical Scale in Feet
020 20
Vertical Exaggeration: 3X
Fill
Upper Loose/Soft to Medium Dense/Medium
Stiff Sands and Silts (Alluvium)
Lower Medium Dense to Dense/Stiff
Gravels, Sand and Silt (Alluvium)
Loose/Medium Stiff Sand and Silt with
Thin Layers of Stiff Peat (Alluvium)
0.01
0.1
1
10
0.01 0.1 15% Damped Spectral Acceleration, Sa(g)Period (seconds)
Recommended Site-Specific MCEr Response
Spectrum
Recommended Site-Specific MCERResponse Spectrum
Logan Avenue N/N 8th Street Development
Renton, Washington
Figure 7
Project: 23325-001-00 Executed: 5/16/2018
APPENDICES
APPENDIX A Field Explorations
October 29, 2019 | Page A-1 File No. 23325-001-00
APPENDIX A
FIELD EXPLORATIONS
Subsurface conditions at the site were evaluated by drilling 24 borings (B-1, B-2, PB-1, AB-1 through AB-3,
OB-1 through OB-7, GEI-1, GEI-2, B-1-19 through B-4-19, and GEI-1-19 through GEI-5-19) and advancing
six cone penetration tests (CPTs) (CPT-1 through CPT-6) to depths ranging from approximately 10 to 85 feet
below existing site grades. CPTs were advanced to practical refusal. The borings were completed by
Advanced Drill Technologies, Inc. from April 3 to April 4, 2018, from July 29 to August 1 and August 23,
2019. The CPTs were completed by In Situ Engineering on April 3, 2018.
The locations of the explorations were estimated by taping/pacing from existing site features as well as
surveyed. The approximate exploration locations are shown on the Figure 2, Site Plan.
Borings
The borings were completed using a D-50 track mounted drill rig with continuous-flight, hollow-stem auger
drilling equipment. The borings were continuously monitored by a technician 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. 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, Key to Exploration Logs. 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-26. 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.
October 29, 2019 | Page A-2 File No. 23325-001-00
Monitoring Wells
A groundwater monitoring wells was installed next to boring GEI-3-19. The monitoring well was constructed
using 2-inch-diameter polyvinyl chloride (PVC) casing. The depth to which the casing was installed was
selected based on our understanding of subsurface soil and groundwater conditions encountered during
drilling. The lower portion of the casing was slotted to allow entry of water into the casing. Medium sand
was placed in the borehole annulus surrounding the slotted portion of the casing. A bentonite seal was
placed above the slotted portion of the casing. The monitoring well was protected by installing flush-mount
steel monuments set in concrete. Completion details for the monitoring well is shown on Figure A-24.
Groundwater levels in the monitoring wells were measured on August 8, 12 and 23, 2019, as summarized
in the main body of the report.
The groundwater monitoring wells should be abandoned during construction in accordance with the
procedures of the Washington State Department of Ecology.
Cone Penetration Tests
The CPT is a subsurface exploration technique in which a small-diameter steel tip with adjacent sleeve is
continuously advanced with hydraulically operated equipment. Measurements of tip and sleeve resistance
allow interpretation of the soil profile and the consistency of the strata penetrated. The tip resistance,
friction ratio and pore water pressure are recorded on the CPT logs. The logs of the CPT probes are
presented at the end of this appendix as Figures A-27 through A-34. The CPT soundings were backfilled in
general accordance with procedures outlined by the Washington State Department of Ecology.
Measured groundwater level in exploration,well, or piezometer
Measured free product in well or piezometer
Distinct contact between soil strata
Approximate contact between soil strata
Contact between geologic units
SYMBOLS TYPICAL
DESCRIPTIONS
GW
GP
SW
SP
SM
FINEGRAINED
SOILS
SILTS ANDCLAYS
NOTE: Multiple symbols are used to indicate borderline or dual soil classifications
MORE THAN 50%RETAINED ONNO. 200 SIEVE
MORE THAN 50%PASSINGNO. 200 SIEVE
GRAVEL
ANDGRAVELLYSOILS
SC
LIQUID LIMITLESS THAN 50
(APPRECIABLE AMOUNTOF FINES)
(APPRECIABLE AMOUNTOF FINES)
COARSEGRAINEDSOILS
MAJOR DIVISIONS GRAPH LETTER
GM
GC
ML
CL
OL
SILTS AND
CLAYS
SANDS WITHFINES
SANDANDSANDY
SOILS
MH
CH
OH
PT
(LITTLE OR NO FINES)
CLEAN SANDS
GRAVELS WITHFINES
CLEAN GRAVELS
(LITTLE OR NO FINES)
WELL-GRADED GRAVELS, GRAVEL -SAND MIXTURES
CLAYEY GRAVELS, GRAVEL - SAND -CLAY MIXTURES
WELL-GRADED SANDS, GRAVELLYSANDS
POORLY-GRADED SANDS, GRAVELLYSAND
SILTY SANDS, SAND - SILT MIXTURES
CLAYEY SANDS, SAND - CLAYMIXTURES
INORGANIC SILTS, ROCK FLOUR,CLAYEY SILTS WITH SLIGHTPLASTICITY
INORGANIC CLAYS OF LOW TOMEDIUM PLASTICITY, GRAVELLYCLAYS, SANDY CLAYS, SILTY CLAYS,LEAN CLAYS
ORGANIC SILTS AND ORGANIC SILTYCLAYS OF LOW PLASTICITY
INORGANIC SILTS, MICACEOUS ORDIATOMACEOUS SILTY SOILS
INORGANIC CLAYS OF HIGHPLASTICITY
ORGANIC CLAYS AND SILTS OFMEDIUM TO HIGH PLASTICITY
PEAT, HUMUS, SWAMP SOILS WITHHIGH ORGANIC CONTENTSHIGHLY ORGANIC SOILS
SOIL CLASSIFICATION CHART
MORE THAN 50%OF COARSEFRACTION RETAINEDON NO. 4 SIEVE
MORE THAN 50%OF COARSEFRACTION PASSINGON NO. 4 SIEVE
SILTY GRAVELS, GRAVEL - SAND -SILT MIXTURES
POORLY-GRADED GRAVELS,GRAVEL - SAND MIXTURES
LIQUID LIMIT GREATERTHAN 50
Continuous Coring
Bulk or grab
Direct-Push
Piston
Shelby tube
Standard Penetration Test (SPT)
2.4-inch I.D. split barrel
Contact between soil of the same geologicunit
Material Description Contact
Graphic Log Contact
NOTE: The reader must refer to the discussion in the report text and the logs of explorations for a proper understanding of subsurface conditions.Descriptions on the logs apply only at the specific exploration locations and at the time the explorations were made; they are not warranted to berepresentative of subsurface conditions at other locations or times.
Groundwater Contact
Blowcount is recorded for driven samplers as the number ofblows required to advance sampler 12 inches (or distance noted).See exploration log for hammer weight and drop.
"P" indicates sampler pushed using the weight of the drill rig.
"WOH" indicates sampler pushed using the weight of thehammer.
Key to Exploration Logs
Figure A-1
Sampler Symbol Descriptions
ADDITIONAL MATERIAL SYMBOLS
NSSSMSHS
No Visible SheenSlight SheenModerate SheenHeavy Sheen
Sheen Classification
SYMBOLS
Asphalt Concrete
Cement Concrete
Crushed Rock/Quarry Spalls
Topsoil
GRAPH LETTER
AC
CC
SOD Sod/Forest Duff
CR
DESCRIPTIONS
TYPICAL
TS
Percent finesPercent gravelAtterberg limitsChemical analysisLaboratory compaction testConsolidation testDry densityDirect shearHydrometer analysisMoisture contentMoisture content and dry densityMohs hardness scaleOrganic contentPermeability or hydraulic conductivityPlasticity indexPoint lead testPocket penetrometerSieve analysisTriaxial compressionUnconfined compressionVane shear
%F%GALCACPCSDDDSHAMCMDMohsOCPMPIPLPPSATXUCVS
Laboratory / Field Tests
PP = 0.0 psf
PP = 0.0 psfAL (LL = 35, PI = 5)
Groundwater observed at approximately 10 feetbelow ground surface during drilling
PP = 0.0 psf
Added drilling mud at 20 feet; no heave observed
PP = 0.0 psf
AL (LL = 47, PI = 10)
PP = 500 psf
15
40
48
23
Topsoil
Gray sandy silt with occasional gravel (stiff, moist) (fill)
Brown silty fine to medium sand with occasional gravel(medium dense, moist to wet)
Gray silty fine sand (very loose, moist) (alluvium)
Gray silt with trace fine sand (very soft to soft, moist)
Gray silty fine sand (very loose, moist to wet)
Brown-gray silt (very soft to soft, wet)
Gray silty fine sand with occasional silt lenses (loose tomedium dense, wet)
Gray fine to medium sand with silt (loose to mediumdense, wet)
Brown silt with organic matter and occasionalhorizontal bedding (stiff, moist)
Gray silty fine sand (medium dense, wet)
With organic matter (wood debris), becomes veryloose
Brown-gray silt (soft, moist)
Gray-light brown silt with organic matter (wood debris)(medium stiff, moist)
Gray fine sand with silt and occasional organic matter(wood debris) (loose, moist)
1
2SA
3a3b
3c
4aAL4b
5a5b
6a6b6c
7
8
9AL
10a
10b
4
18
7
6
12
18
18
18
18
16
2
2
10
12
23
3
6
TS
ML
SM
SM
ML
SM
ML
SM
SP-SM
ML
SM
ML
ML
SP-SM
Notes:
61.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.49503-122.206167
29.5
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
4/4/20184/4/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 2Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-1
Logan Avenue N/N 8th Street Development
Figure A-2
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30
35 Graphic LogGroupClassificationElevation (feet)2520151050-5
PP = 6,500 psfPP = 500 psf
PP = 4,500 - 6,000 psf
Gravels at 55 feet
Broken cobble in shoe
204
159
Gray fine to coarse sand with trace silt (loose, wet)
Brown fibrous peat (soft to medium stiff, moist)
Brown-gray silt (soft to medium stiff, moist)
With occasional peat lenses, becomes medium stiff
Brown fibrous peat with silt lenses (medium stiff,moist)
Gray silty fine to medium sand with peat lenses (loose,moist)
Gray silty fine to coarse sand with occasional gravel
11
12aMC12b
13b13aMC
14
15
16
11
18
18
18
10
0
7
4
6
6
44
25
SP-SM
PT
ML
PT
SM
SM
Sheet 2 of 2Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-1 (continued)
Logan Avenue N/N 8th Street Development
Figure A-2
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35
40
45
50
55
60 Graphic LogGroupClassificationElevation (feet)-10-15-20-25-30
PP = 500 psfAL (LL = 35, PI = 5)Groundwater observed at approximately 8½ feetbelow ground surface during drilling
AL (LL = 117, PI = 33)
AL (LL = 78, PI = 15)
6
10
35
38
61
15
Topsoil
Brown silty fine to coarse sand with gravel (loose,moist) (fill)
Becomes medium dense
Gray silty fine sand (very loose, wet) (alluvium)
Gray sandy silt (very soft to soft, wet)
Brown silty fine sand (very loose, wet)
Brown-gray sandy organic silt (very soft to soft, moistto wet)
Gray fine to coarse sand (dense, wet)
Gray silty fine sand (dense, moist)
Gray fine sand with trace silt (medium dense, moist)
Gray silty fine to medium sand (loose, moist)
Light brown elastic silt with occasional peat (mediumstiff, moist)
Becomes gray and soft to medium stiff
Gray fine sand with silt (very loose to loose, moist)
1MC
2SA
3
4AL
5
6AL
7a
7b
8
9a
9bAL
10a
10b
18
16
18
18
18
18
18
7
10
24
2
2
2
33
23
6
4
TS
SM
SM
ML
SM
OH
SP
SM
SP-SM
SM
MH
SM
Notes:
36.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.494673-122.206018
30
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
4/4/20184/4/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 2Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-2
Logan Avenue N/N 8th Street Development
Figure A-3
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30
35 Graphic LogGroupClassificationElevation (feet)2520151050-5
Gray-brown fine to medium sand with brown silt lensesand occasional organic matter (wood debris)(loose, moist)
11128 SP
Sheet 2 of 2Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-2 (continued)
Logan Avenue N/N 8th Street Development
Figure A-3
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35 Graphic LogGroupClassificationElevation (feet)
PP = 0.0 psf
Groundwater observed at approximately 9 feetbelow ground surface during drilling
5
9
39
9
83
Approximately 6 inches of asphalt concrete pavement
Gravel
Brown silty fine to coarse sand with gravel (loose,moist) (fill)
Brown fine to coarse sand with silt and gravel (mediumdense, moist)
Gray silt with sand (very soft to soft, moist) (alluvium)
Gray medium to coarse sand with trace silt (mediumdense, wet)
Gray fine to medium sand (loose, wet)
1MC
2SA
3%F
4
5
11
18
18
18
24
2
11
7
AC
GP
SM
SP-SM
ML
SP-SM
SM
Notes:
11.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.495257-122.206812
30
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
4/3/20184/3/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 1Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring AB-1
Logan Avenue N/N 8th Street Development
Figure A-4
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10 Graphic LogGroupClassificationElevation (feet)2520
PP = 500 - 1,000 psfAL (LL = 37, PI = 7)
13
9
8139
27
Grass
Brown silty fine to coarse sand with gravel and organicmatter (roots, wood debris) (loose, moist) (fill)
Grades to fine to medium, becomes dense
Brown-gray fine to coarse sand with silt (mediumdense, dry)
Brown peat with silt (medium stiff, moist) (alluvium)
Gray sandy silt with occasional peat lenses (mediumstiff, moist)
Gray silty fine to medium sand (medium dense, wet)
1MC
2SA
3
4aMC4bAL
5
18
18
16
33
22
6
19
Grass
SM
SP-SM
PT
ML
SM
Notes:
11.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.494096-122.206213
31
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
Groundwater not observed at time of exploration
4/3/20184/3/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 1Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring AB-2
Logan Avenue N/N 8th Street Development
Figure A-5
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10 Graphic LogGroupClassificationElevation (feet)302520
Groundwater observed at approximately 4½ feetbelow ground surface during drilling
PP = 0.0 psf
12
16 16
Topsoil
Brown-orange silty fine to coarse sand with occasionalgravel (loose, moist) (fill)
Becomes orange fine to medium and medium dense
Becomes loose
Gray fine to medium sand with trace silt (loose, wet)(alluvium)
Brown-gray sandy silt (very soft, moist)
Becomes medium stiff
Gray silty fine sand (loose, moist)
1MC
2SA
3a3b
4
5a5b
16
18
16
18
7
1
6
TS
SM
SP-SM
ML
SM
Notes:
11.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.495154-122.202615
29.5
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
4/4/20184/4/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 1Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring AB-3
Logan Avenue N/N 8th Street Development
Figure A-6
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10 Graphic LogGroupClassificationElevation (feet)2520
Groundwater observed at approximately 4½ feetbelow ground surface during drilling
PP = 3,000 - 4,000 psf
PP = 500 psfAL (non-plastic)
10
7
37
9
Topsoil
Brown silty fine to coarse sand with gravel (loose,moist) (fill)
Brown fine to coarse gravel with silt and sand (mediumdense, moist)
Gray silty fine sand with oxidation staining (loose,moist) (alluvium)
Gray silt with trace fine sand (medium stiff, moist)
Gray silty fine to medium sand (very loose, wet)
Grades to fine to coarse, becomes loose
Gray sandy silt (soft, wet)
Gray silty fine sand (very loose to loose, wet)
1MC
2SA
3
4
5
6
7a7bAL
8
1
18
6
18
16
18
18
25
8
3
6
3
3
4
TS
SM
GW-GM
SM
ML
SM
ML
SM
Notes:
26.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.495213-122.205624
29
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
4/3/20184/3/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 1Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring OB-1
Logan Avenue N/N 8th Street Development
Figure A-7
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25 Graphic LogGroupClassificationElevation (feet)252015105
Groundwater observed at approximately 4 feetbelow ground surface during drillingPP = 1,000 - 1,500 psf
9
157
Topsoil
Brown-gray silty fine to coarse sand with gravel andorganic matter (grass roots) (loose, moist) (fill)
Brown-orange fine to coarse sand with silt and gravel(loose, dry)
Gray silt with fine sand and occasional peat, orangeoxidation staining (soft, moist) (alluvium)
Brown sandy silt with oxidation staining (soft, wet)
Gray silty fine sand (very loose to loose, wet)
Peat with interbedded silt (very soft to soft, moist)
Gray silty fine sand (medium dense, moist)
Gray silt with fine sand and occasional organic matter(wood debris) (medium stiff, moist)
Gray silty fine sand (loose, moist)
Gray fine to medium sand with silt (loose to mediumdense, moist)
1MC
2
3a3b
4
5a5bMC
6
7a7b
8
18
18
18
18
18
18
18
5
3
4
2
21
5
10
TS
SM
SP-SM
ML
ML
SM
PT
SM
ML
SM
SP-SM
Notes:
26.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.494579-122.205501
29
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
4/3/20184/3/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 1Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring OB-2
Logan Avenue N/N 8th Street Development
Figure A-8
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25 Graphic LogGroupClassificationElevation (feet)252015105
PP = 500 psf
PP = 0.0 psfPP = 500 psfAL (LL = 100, PI = 32)
13
32
170
63
10
Grass
Gray-brown silty fine to coarse sand with gravel andorganic matter (roots) (loose, moist) (fill)
Brown fine to medium sand with silt and gravel,orange oxidation staining (medium dense, moist)
Gray silty fine sand (loose, moist) (alluvium)
Becomes very loose, wet
Brown peat with interbedded silt (very soft to soft, wet)
Gray fine sand with silt (stiff, wet)
Gray silt with fine sand and occasional organic matter(roots) (very soft to soft, wet)
Gray fine to moist sand with trace silt (medium dense,wet)
1
2SA
3a3b
4MC
5a5bMC
6
7a7bAL
8
18
18
18
18
18
18
18
19
9
2
2
9
2
13
Grass
SM
SW-SM
SM
PT
SP-SM
ML
SP-SM
Notes:
26.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.494747-122.205271
29
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
Groundwater not observed at time of exploration
4/3/20184/3/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 1Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring OB-3
Logan Avenue N/N 8th Street Development
Figure A-9
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25 Graphic LogGroupClassificationElevation (feet)252015105
PP = 3,000 psfAL (LL = 54, PI = 19)
PP = 0.0 psf
5
29
Topsoil
Brown silty fine to coarse sand with gravel (loose,moist) (fill)
Brown-orange fine to medium sand with trace silt(medium dense, moist)
Becomes gray and loose
Gray sandy elastic silt (medium stiff to stiff, moist)(alluvium)
Gray silty fine to medium sand (loose, wet)
Gray silt with fine sand (medium stiff, wet)
Gray silty fine sand (medium dense, wet)
Gray fine to medium sand with trace silt (very loose,wet)
Sandy silt (very soft to soft, wet)
Gray fine to medium sand with trace silt (mediumdense, wet)
Becomes loose
1MC
2
3a3bAL
4a4b
5
6a6b
7
8
9
12
12
16
18
18
18
18
18
26
8
6
14
2
11
12
5
TS
SM
SP
MH
SM
ML
SM
SP-SM
ML
SP
Notes:
31.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.494866-122.204484
29
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
Groundwater not observed at time of exploration
4/4/20184/4/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 1Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring OB-4
Logan Avenue N/N 8th Street Development
Figure A-10
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30 Graphic LogGroupClassificationElevation (feet)2520151050
PP = 4,000 - 5,000 psf
PP = 0.0 - 500 psf
Groundwater observed at approximately 9½ feetbelow ground surface during drilling
14 13
Grass
Brown silty fine to medium sand with gravel (loose,moist) (fill)
Becomes brown to orange
Orange silty fine sand with trace gravel (loose, wet)(alluvium)
Gray silt with occasional organic matter (roots)(medium stiff, moist)
Gray fine sand with silt (loose, wet)
Becomes medium dense
Gray silty fine to coarse sand (loose, wet)
Gray fine to medium sand with trace silt (very loose toloose, wet)
Peat (soft to medium stiff, moist)
Gray fine to coarse sand with trace silt and occasionalgravel (medium dense, wet)
1
2SA
3a3b
4
5
6a6b
7a7b
8
18
16
18
18
18
18
18
8
6
8
14
8
4
14
Grass
SM
SM
ML
SP-SM
SM
SP-SM
PT
SP-SM
Notes:
26.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.495127-122.204148
29
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 1Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring OB-5
Logan Avenue N/N 8th Street Development
Figure A-11
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25 Graphic LogGroupClassificationElevation (feet)252015105
PP = 0.0 - 500 psf
PP = 0.0 psf
PP = 0.0 psf
Added drilling mud at 25 feet; 12 inches of heaveobserved
11
36 46
Topsoil
Brown silty fine to coarse sand with occasional graveland organic matter (grass roots) (loose, moist) (fill)
Gray silty fine sand with occasional organic matter(roots) (medium dense, wet)
Brown-orange fine to coarse sand with gravel (veryloose, wet)
Gray silty fine sand (very loose, moist to wet) (alluvium)
Gray sandy silt with peat lenses and organic matter(wood debris) (soft, moist)
Gray sandy silt with trace organic matter (roots) (soft,wet)
Gray silt with trace fine sand and organic matter(roots, wood debris) (soft to medium stiff, wet)
Gray silty fine to medium sand (loose, wet)Becomes fine sand
Gray silty fine to medium sand (medium dense, wet)
1MC
2
3a3b%F
4
5a5b5c
6
7a7b
8
9
4
18
18
18
18
18
18
18
13
2
2
3
4
5
19
14
TS
SM
SM
SM
SM
ML
ML
ML
SM
SM
Notes:
31.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.495094-122.205341
29
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
Groundwater not observed at time of exploration
4/3/20184/3/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 1Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring OB-6
Logan Avenue N/N 8th Street Development
Figure A-12
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30 Graphic LogGroupClassificationElevation (feet)2520151050
PP = 0.0 - 500 psf
PP = 500 psfGroundwater observed at approximately 8¼ feetbelow ground surface during drilling
AL (LL = 53, PI = 10)PP = 0.0 psf
10
30
50
61
Topsoil
Gray silty fine to coarse sand with gravel and organicmatter (roots) (loose, moist) (fill)
Gray silty fine to coarse sand with gravel (mediumdense, moist)
Gray sandy silt (medium stiff, wet) (alluvium)
Gray silty fine to medium sand (loose, wet)
Gray sandy elastic silt (very soft, wet)
Gray silty fine to medium sand (very loose, wet)
Gray sandy elastic silt with peat lenses (very soft tosoft, moist)
Brown sandy silt (soft, moist)
Gray fine to medium sand (very loose, wet)
Becomes very loose to loose
Gray-brown silt with organic matter (roots) (soft tomedium stiff, moist)
Peat with silt lenses (soft to medium stiff, moist)
1MC
2
3a%F3b
4a4b
5
6aAL6b
7a7b
8a
8b8c
14
18
18
18
18
18
18
19
5
1/12"
3
2
3
4
TS
SM
SM
ML
SM
MH
SM
MH
ML
SP
ML
PT
Notes:
26.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.49496-122.203687
29
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
4/4/20184/4/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 1Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring OB-7
Logan Avenue N/N 8th Street Development
Figure A-13
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25 Graphic LogGroupClassificationElevation (feet)252015105
Groundwater observed at approximately 12½feet below ground surface during drilling
AL (LL = 93, PI = 33)PP = 0.0 - 500 psf
6
36
52
72
Topsoil
Brown silty fine to coarse gravel with sand (loose,moist) (fill)
Brown silty fine to coarse sand with occasional gravel(medium dense, moist)
Gray silt with fine to coarse sand lenses (very stiff,moist) (alluvium)
Orange fine to medium sand with trace gravel(medium dense, moist)
Gray silt with sand (medium stiff, moist)Becomes stiff, wet
Gray silty fine to medium sand (loose, wet)
Gray sandy silt with thin lens of peat (medium stiff tostiff, wet)
Gray fine to medium sand with trace silt (loose, wet)
Gray-brown silt with peat lenses (very soft to soft,moist)With occasional organic matter (wood debris, roots)
Gray fine to medium sand (medium dense, wet)
1MC
2a2b
2c
3%F
4
5
6a6b
7aAL7b
8
14
18
18
6
18
18
18
18
6
13
5
8
2
16
TS
GM
SM
ML
SP
ML
SM
ML
SP-SM
ML
SP
Notes:
26.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.494298-122.203708
30
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
4/4/20184/4/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 1Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-1
Logan Avenue N/N 8th Street Development
Figure A-14
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25 Graphic LogGroupClassificationElevation (feet)252015105
PP = 500 psf
Groundwater observed at approximately 8 feetbelow ground surface during drillingPP = 500 psf
12
13 11
Topsoil
Gray silty fine to coarse sand with gravel (loose, moist)(fill)
Gray fine to medium sand with silt and gravel (mediumdense, moist)
Becomes very loose, wet
Gray sandy silt (very soft to soft, wet) (alluvium)
Gray silt with fine sand (very soft, wet)
Light gray-brown silt with thin peat lenses (very soft,wet)
Gray silty fine to medium sand (loose, wet)
1MC
2SA
3a3b
4a4b
5
18
18
18
18
18
2
1/12"
5
TS
SM
SP-SM
ML
ML
ML
SM
Notes:
11.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.49451-122.202649
30
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
4/4/20184/4/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 1Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-2
Logan Avenue N/N 8th Street Development
Figure A-15
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10 Graphic LogGroupClassificationElevation (feet)2520
Groundwater observed at approximately 6¼ feetbelow ground surface during drilling
PP = 500 psf
PP = 0.0 psfAL (LL = 120, PI = 33)
Added drilling mud at 20 feet; 13 inches of heaveobserved
11
34
100
16
73
Topsoil
Brown silty fine to coarse sand with gravel and organicmatter (roots) (loose, moist) (fill)
Becomes medium dense
Gray silty fine to coarse sand (loose, wet) (alluvium)
With gravel, becomes very loose to loose
Gray silt with sand (soft to medium stiff, wet)
Gray fine to medium sand with silt (very loose, wet)
Brown organic silt with organic matter (roots) (very softto soft, wet)
Brown-dark brown fibrous peat with silt lenses(medium stiff to stiff, moist)
Gray silty fine sand (loose, moist to wet)
Gray fine to coarse sand with trace silt (mediumdense, wet)
1
2SA
3a3b
4a4b
5%F
6a6bAL
7a7b
8
9
6
5
8
18
18
18
18
0
14
5
4
3
2
8
21
7
TS
SM
SM
ML
SP-SM
OL
PT
SM
SP-SM
Notes:
36.5 NS
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.495414-122.204592
29
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
4/3/20184/3/2018
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey.
Sheet 1 of 2Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring PB-01
Logan Avenue N/N 8th Street Development
Figure A-16
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30
35 Graphic LogGroupClassificationElevation (feet)2520151050-5
PP = 0.0 psf216Gray silt with fine sand and organic matter (peat, wooddebris) (loose, wet)
Dark brown fibrous peat with occasional silt (stiff,moist)
10a10bMC
16 9 ML
PT
Sheet 2 of 2Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring PB-01 (continued)
Logan Avenue N/N 8th Street Development
Figure A-16
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35 Graphic LogGroupClassificationElevation (feet)
Groundwater observed during drilling atapproximately 8.9 feet below ground surface
Driller added mud
Attempted to collect Shelby tube sample at 21.5to 23.5 feet; no recovery
28 10
Approximately 8 inches of asphalt concrete pavementand base course
Brown fine to medium silty sand (very loose to loose,moist) (fill)
Gray silt with trace of peat (soft to medium stiff, moist)(alluvium)
Gray fine to medium sand with silt (very loose to loose,moist)
Grades to very loose, wet
Grades to loose to medium dense, wet
Gray silt with sand and trace peat (very loose, wet)
Brown peat with silt (very soft to soft, wet)
Gray silt with sand (very soft to soft, wet)
Gray silty fine to medium sand (loose, wet)
Brown-gray silt with sand with trace peat (soft tomedium stiff, wet)
1
2
3
4%F
5
6
7
8
12
14
14
13
18
12
18
18
4
4
1
10
1
2
8
4
AC
SM
ML
SP-SM
ML
PT
ML
SM
ML
Notes:
81.5 BZ
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.494803-122.206424
29
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
7/29/20197/29/2019
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on Locational Survey. Vertical approximated based on Topographic Survey.
Sheet 1 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-1-19
Logan Avenue N/N 8th Street Development
Figure A-17
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30
35 Graphic LogGroupClassificationElevation (feet)2520151050-5
AL (LL = 54; PI = 16)
AL (LL = 0; PI = 0)
48
Brown peat with silt (stiff, wet)
Brown-gray elastic silt with occasional sand andorganic matter (roots) (very stiff, wet)
Gray silty fine to medium sand (medium dense, wet)
Brown peat with gray fine to medium sand lenses (stiffto very stiff, wet)
Gray silty fine to medium sand (medium dense, wet)
Gray-brown silt with peat lenses (very stiff, moist)
Gray silty fine to medium sand (medium dense todense, wet)
Grades to coarse sand
Gray fine to coarse sand with silt and occasional gravel(very dense, wet)
Brown-gray non-plastic silt with occasional sand andorganic matter (roots) (medium stiff, moist)
Gray fine sand (dense, wet)
9MC
10AAL10B
11
12
13
14
15
16AL
17
18
18
18
15
13
10
10
18
18
10
23
16
17
36
66
80
5
30
PT
MH
SM
PT
SM
ML
SM
SP-SM
ML
SM
Sheet 2 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-1-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-17
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35
40
45
50
55
60
65
70
75 Graphic LogGroupClassificationElevation (feet)-10-15-20-25-30-35-40-45
Gray fine to medium sand with silt lenses (dense, wet)181837 SP-SM
Sheet 3 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-1-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-17
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)80 Graphic LogGroupClassificationElevation (feet)-50
Groundwater observed during drilling atapproximately 9.6 feet below ground surface
Heave; driller added mud
24 6
Approximately 6 inches of topsoil
Brown silty fine to coarse sand with occasional gravel(very dense, moist) (fill)
Grades to medium dense
Gray silt with occasional organic matter (roots) (verysoft to soft, moist) (alluvium)
Gray silty fine to medium sand (very loose, wet)
Gray fine to medium sand with silt (loose, wet)
Grades to medium dense
Gray silt with occasional peat (medium stiff, wet)
Gray silty fine sand (loose, wet)
1
2
3
4
5
6%F
7
8
9
14
14
17
17
18
18
12
18
58
25
2
3
9
7
24
6
TS
SM
ML
SM
SP-SM
ML
SM
Notes:
81.5 BZ
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.494581-122.20621
30
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
7/29/20097/29/2019
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on Locational Survey. Vertical approximated based on Topographic Survey.
Sheet 1 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-2-19
Logan Avenue N/N 8th Street Development
Figure A-18
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30
35 Graphic LogGroupClassificationElevation (feet)2520151050-5
Gray silt with fine to medium sand (medium stiff, wet)
With organic matter (roots) (medium stiff, wet)
Brown peat with sand lenses (medium stiff, wet)
Brown-gray silt with wood debris (medium stiff, wet)
Brown peat (soft to medium stiff, wet)
Gray silt (soft to medium stiff, wet)
Gray silty fine to coarse sand (dense, wet)
Gray fine to coarse sand with silt and gravel (mediumdense, wet)
(very dense, wet)
Brown-gray silt with occasional organic matter (roots)(medium stiff, wet)
Gray fine to medium sand with silt (very dense, wet)
10
11
12A12B
13a13B
14
15
16
17
18
18
18
18
18
6
7
17
16
17
6
6
7
4
44
21
87
7
56
ML
PT
ML
PT
ML
SM
SP-SM
ML
SP-SM
Sheet 2 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-2-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-18
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35
40
45
50
55
60
65
70
75 Graphic LogGroupClassificationElevation (feet)-10-15-20-25-30-35-40-45
Gray silty fine to medium sand (medium dense, wet)191429 SM
Sheet 3 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-2-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-18
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)80 Graphic LogGroupClassificationElevation (feet)-50
Groundwater observed during drilling atapproximately 10.8 feet below ground surface
Driller added mud
37 76
Approximately 6 inches of topsoil
Brown silty fine to medium sand with occasional gravel(medium dense, moist) (fill)
Gray-brown silt with sand and occasional peat lenses(medium stiff, moist) (alluvium)
Gray fine to coarse sand with silt (medium dense, wet)
Gray silty fine to medium sand (medium dense, wet)
Gray silt (very soft to soft, wet)
Gray silty fine to medium sand (very loose, wet)
1
2
3
4
5%F
6
7
8
9A
9B
14
16
17
14
11
6
12
18
26
27
6
8
24
20
22
2
TS
SM
ML
SP-SM
SM
ML
SM
Notes:
81.5 BZ
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.494222-122.206267
31
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
7/30/20197/30/2019
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on Locational Survey. Vertical approximated based on Topographic Survey.
Sheet 1 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-3-19
Logan Avenue N/N 8th Street Development
Figure A-19
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30
35 Graphic LogGroupClassificationElevation (feet)302520151050
48
Gray sandy silt (stiff, wet)
Gray silty fine to medium sand with occasional gravel(medium dense, wet)
Gray silt with occasional peat lenses (very stiff, wet)
Gray silty fine to medium sand (medium dense, wet)
Sandy silt (stiff, wet)
Gray silty fine sand with occasional peat lenses (looseto medium dense, wet)
Brown peat with silt (very stiff, moist)
Gray fine to medium sand with silt (medium dense,wet)
Gray fine to coarse sand with silt and gravel (dense,wet)
Grades to medium dense
Gray silt with occasional roots (hard, wet)
Gray fine to medium sand with silt and occasional
10A
10B
11A
11B
12AMC
12B
13A
13B
14
15
16
17
18A
18B
17
18
16
16
9
14
10
7
16
18
29
10
24
40
34
29
25
35
ML
SM
ML
SM
ML
SM
PT
SP-SM
SP-SM
ML
SP-SM
Sheet 2 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-3-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-19
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35
40
45
50
55
60
65
70
75 Graphic LogGroupClassificationElevation (feet)-5-10-15-20-25-30-35-40-45
gravel (dense, wet)
Grades to medium dense
Gray sandy silt (stiff, wet)
19A
19B
12 15
ML
Sheet 3 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-3-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-19
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)80 Graphic LogGroupClassificationElevation (feet)-50
Groundwater observed during drilling atapproximately 12.1 feet below ground surface
AL (LL = 63; PI = 14)
36
60
30
Approximately 1 inch of asphalt concrete pavement
Approximately 3½ inches of gravel base coarse
Brown-gray silty fine to coarse sand with gravel(medium dense, moist) (fill)
Gray silty fine sand (medium dense, moist) (alluvium)
Gray sandy silt (soft, moist)
With peat lenses (soft to medium stiff, moist)
Gray silty fine to medium sand (very loose, moist)
Gray sandy silt with organic matter (roots) (very stiff,wet)
Gray fine sand with silt (medium dense, wet)
Gray silt with occasional roots (very soft to soft, wet)
Gray elastic silt with occasional sand (medium stiff,wet)
1
2A
2B
3
4A
4B
5A
5B%F
6A
6B
7
8
9AL
18
13
18
18
18
18
18
18
28
5
3
4
17
17
2
5
AC
CR
SM
SM
ML
SM
ML
SM
ML
MH
Notes:
86.5 BZ
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.49527-122.20641
29
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
8/23/20198/23/2019
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on Locational Survey. Vertical approximated based on Topographic Survey.
Sheet 1 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-4-19
Logan Avenue N/N 8th Street Development
Figure A-20
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30
35 Graphic LogGroupClassificationElevation (feet)2520151050-5
Driller noted gravel at 50 feet
AL (LL = 94; PI = 28)
7
79
25
4
20
Gray silty fine sand with silt lens (medium dense, wet)
Gray fine to coarse gravel with sand (dense, wet)
Grades to medium dense, wet
Gray to brown-gray elastic silt with sand andoccasional wood (stiff, wet)
Gray silty fine to medium sand (dense, wet)
10
11
12
13SA
14
15
16AL
17%F
18
18
18
18
10
7
7
18
18
18
4
6
14
31
22
23
12
31
20
SM
GP
MH
SM
Sheet 2 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-4-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-20
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35
40
45
50
55
60
65
70
75 Graphic LogGroupClassificationElevation (feet)-10-15-20-25-30-35-40-45
25 7Gray fine to medium sand with silt (loose, wet)
Gray silty fine to medium sand with occasional silt(medium dense, wet)
19%F
20
12
18
9
26
SP-SM
SM
Sheet 3 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring B-4-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-20
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)80
85 Graphic LogGroupClassificationElevation (feet)-50-55
Groundwater observed during drilling atapproximately 13 feet below ground surface
Driller added mud
17 13
Approximately 6 inches of topsoil
Brown silty fine to coarse sand with gravel andoccasional roots (medium dense, moist) (fill)
Grades to very loose, moist
Gray sandy silt (very soft, moist) (alluvium)
Gray silty fine sand (very loose, wet)
Gray sandy silt with occasional organic matter (roots)(stiff, wet)
Gray silty fine to medium sand with occasional organicmatter (roots) (medium dense, wet)
Gray silt (very stiff, wet)
Gray silty fine sand (medium dense, wet)
1
2
3%F
4A
4B
5
6
7
8
9A
9B
16
17
15
18
18
18
17
18
23
10
1
2
3
14
12
18
TS
SM
ML
SM
ML
SM
ML
SM
Notes:
81.5 BZ
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.494669-122.203797
30
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
7/30/20197/30/2019
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on Locational Survey. Vertical approximated based on Topographic Survey.
Sheet 1 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-1-19
Logan Avenue N/N 8th Street Development
Figure A-21
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30
35 Graphic LogGroupClassificationElevation (feet)2520151050-5
100
Gray sandy silt with peat lenses (stiff, wet)
Gray silty fine sand with occasional organic matter(wood debris) (medium dense, wet)
Brown peat with sand (medium stiff, wet)
Grades to stiff
Gray silty fine to medium sand with occasional organicmatter (wood debris) (dense, wet)
Brown-gray peat with interbedded silt lenses (very stiff,moist)
Gray-brown fine to medium sand with silt (mediumdense, wet)
Brown peat with interbedded silt lenses (stiff, wet)
Gray sandy silt with interbedded peat lenses (very stiff,wet)
10
11
12
13A13BMC
14
15
16A
16B
17
18A
18B
18
15
16
18
18
18
18
18
18
9
20
17
7
9
35
23
11
17
ML
SM
PT
SM
PT
SP-SM
PT
ML
Sheet 2 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-1-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-21
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35
40
45
50
55
60
65
70
75 Graphic LogGroupClassificationElevation (feet)-10-15-20-25-30-35-40-45
Gray silty fine sand with interbedded silt lenses(medium dense, wet)
Gray silt (hard, wet)
Gray silty fine sand (dense, wet)
191833
SM
ML
SM
Sheet 3 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-1-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-21
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)80 Graphic LogGroupClassificationElevation (feet)-50
Groundwater observed during drilling atapproximately 9 feet below ground surfaceDriller added mud
21 6
Approximately 6 inches of topsoil
Brown fine to coarse sand with gravel (medium dense,moist) (fill)
Gray silt with occasional roots and oxidation stains(very stiff, moist)
Brown silty fine to coarse sand with occasional gravel(loose, moist) (alluvium)
Gray silt with sand lenses and oxidation stains (stiff,moist)
Gray silty fine sand (medium dense, wet)
Grades to very loose to loose
Gray silt with peat lenses (very soft to soft, wet)
Grades to very stiff
Gray fine to coarse sand with silt and occasional wooddebris (medium dense, wet)
Brown peat (soft to medium stiff, wet)
1
2A
2B
3A
3B
4
5
6
7
8A8B%F
9
15
15
18
15
14
18
18
16
18
9
14
18
4
2
17
4
TS
SM
ML
SM
ML
SM
ML
SP-SM
PT
Notes:
81.5 BZ
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.494274-122.203771
30
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
7/31/20197/31/2019
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on Locational Survey. Vertical approximated based on Topographic Survey.
Sheet 1 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-2-19
Logan Avenue N/N 8th Street Development
Figure A-22
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30
35 Graphic LogGroupClassificationElevation (feet)2520151050-5
Grades to medium stiff to stiff
Gray silt with occasional wood debris (medium stiff,wet)
Brown peat with silt lenses (medium stiff, wet)
Gray silty fine sand with occasional wood debris(loose, wet)
Gray silt (soft to medium stiff, wet)
With wood debris
Gray fine to medium sand with silt (dense, wet)
With silt lens and wood debris, grades to mediumdense
Brown peat with interbedded silt lenses (stiff, moist)
Gray silt with sand lenses (stiff, wet)
10
11A
11B
12
13
14
15
16
17
18
18
18
18
18
18
18
18
18
18
8
5
4
4
7
32
19
12
15
ML
PT
SM
ML
SP-SM
PT
ML
Sheet 2 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-2-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-22
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35
40
45
50
55
60
65
70
75 Graphic LogGroupClassificationElevation (feet)-10-15-20-25-30-35-40-45
Gray silty fine to medium sand (medium dense, wet)191823 SM
Sheet 3 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-2-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-22
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)80 Graphic LogGroupClassificationElevation (feet)-50
Groundwater observed during drilling atapproximately 9 feet below ground surface
Driller added mud
32
24
45
16
Approximately 6 inches of topsoil
Brown silty fine to coarse sand with gravel (dense,moist) (fill)
Brown-gray silty fine sand with occasional wood debris(loose, wet) (alluvium)
Gray fine to coarse sand with silt (loose, wet)
Gray silty fine to medium sand (medium dense, wet)
1
2
3
4SA
5
6
7
8%F
9
11
4
14
18
16
18
15
18
42
8
7
7
6
6
12
14
TS
SM
SM
SP-SM
SM
Notes:
81.5 BZ
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.49445-122.203359
30
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
7/31/20197/31/2019
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on Locational Survey. Vertical approximated based on Topographic Survey.
Sheet 1 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-3-19
Logan Avenue N/N 8th Street Development
Figure A-23
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30
35 Graphic LogGroupClassificationElevation (feet)2520151050-5
Dark brown peat lenses (stiff, moist)
Gray silt with interbedded fine sand and peat lenses(stiff, wet)
Gray silt with occasional organic matter (roots) (verystiff, wet)
Gray fine to medium sand with silt and occasionalwood debris (medium dense, wet)
Grades to very loose to loose
Gray silt with peat lenses (medium stiff, moist)
Gray silty fine sand with peat lenses (loose, wet)
Gray fine to medium sand with silt (dense, wet)
Gray silty fine sand with peat lenses (medium dense,wet)
Gray silt with peat lenses (stiff, moist)
Gray silty fine sand with occasional wood debris(medium dense, wet)
Dark brown-gray silt with peat lenses (stiff, moist)
Gray silty fine to medium sand (medium dense, wet)
10
11
12A
12B
13
14A
14B
15
16A
16B
17A
17B
18
18
18
18
7
18
18
18
18
18
13
11
21
4
6
41
14
13
18
PT
ML
ML
SP-SM
ML
SM
SP-SM
SM
ML
SM
ML
SM
Sheet 2 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-3-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-23
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35
40
45
50
55
60
65
70
75 Graphic LogGroupClassificationElevation (feet)-10-15-20-25-30-35-40-45
Gray silty fine sand with peat lenses (dense, wet)191837 SM
Sheet 3 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-3-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-23
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)80 Graphic LogGroupClassificationElevation (feet)-50
Refer to Material Description in Log of BoringGEI-3-19
Groundwater measured on 8/12/19 to depth of8.1 feet; groundwater elevation 21.9 feetGroundwater measured on 8/23/19 to depth of8.2 feet; groundwater elevation 21.8 feet
Concrete surfaceseal
2-inch Schedule 40PVC well casingBentonite seal
10-20 silica sandbackfill2-inch Schedule 40PVC screen,0.010-inch slotwidth
1
4
5
15
16
StartDrilled8/1/2019
HammerData
Date MeasuredHorizontalDatum
Vertical Datum
LatitudeLongitude
DrillingEquipment
Top of CasingElevation (ft)
Elevation (ft)
Groundwater Depth toWater (ft)
Notes:
Surface Elevation (ft)
Logged By
Diedrich D50 drill rig
29.8030
47.494454-122.20333 WA State Plane NorthNAD83 (feet)8/8/2019 8.00
16 DrillingMethod8/1/2019
End
Checked By DrillerTotalDepth (ft)
Autohammer140 (lbs) / 30 (in) Drop
22.00
BZ
LA
Advance Drill Technologies,Inc.
DOE Well I.D.: BKU952A 2-in well was installed on 8/1/2019 to a depth of 16 ft.
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on Locational Survey. Vertical approximated based on Topographic Survey.
Steel surface
monument
Elevation (feet)252015Depth (feet)0
5
10
15
FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingWater LevelIntervalRecovered (in)Blows/footCollected SampleGraphic LogGroupClassificationWELL LOG
MoistureContent (%)FinesContent (%)Sheet 1 of 1Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Monitoring Well GEI-3-19a
Logan Avenue N/N 8th Street Development
Figure A-24
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_WELL_%F
Groundwater observed during drilling atapproximately 9.7 feet below ground surface
Driller added mud
22 18
Approximately 6 inches of topsoil
Brown silty fine to coarse sand with gravel (dense,moist) (fill)
Becomes gray and very loose to loose, moist
Gray silt with sand and wood debris (soft to mediumstiff, moist) (alluvium)
Gray silty fine sand (medium dense, moist)
(very loose to loose, wet)
Gray silt with sand lenses and wood debris (very soft,wet)
Gray fine sand with silt (loose, wet)
Gray silt with sand lenses and occasional wood debris(soft to medium stiff, wet)
Dark brown peat (soft to medium stiff, wet)
Gray silty fine sand (medium dense, wet)
1
2
3A
3B
4%F
5
6A
6B
7A
7B
8A
8B
9
16
15
16
15
18
18
18
15
45
4
11
4
1
6
4
13
TS
SM
ML
SM
ML
SP-SM
ML
PT
SM
Notes:
81.5 BZ
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.494585-122.202964
30
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
8/1/20198/1/2019
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on Locational Survey. Vertical approximated based on Topographic Survey.
Sheet 1 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-4-19
Logan Avenue N/N 8th Street Development
Figure A-25
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30
35 Graphic LogGroupClassificationElevation (feet)2520151050-5
Dark brown peat with silt lenses (soft to medium stiff,moist)
Gray silt with occasional peat lenses (soft to mediumstiff, wet)
(stiff, wet)
(medium stiff, wet)
Dark brown peat (medium stiff, wet)
Gray sandy silt with occasional wood debris (mediumstiff, wet)
Gray fine to medium sand with silt (medium dense,wet)
Grades to dense
Dark brown peat with silt and sand lenses (very stiff,wet)
Grades to stiff
Gray sandy silt (stiff, wet)
10A
10B
11
12
13A
13B
14A
14B
15
16
17
18A
18B
18
18
18
18
18
18
17
18
18
4
9
7
6
7
22
32
17
10
PT
ML
PT
ML
SP-SM
PT
ML
Sheet 2 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-4-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-25
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35
40
45
50
55
60
65
70
75 Graphic LogGroupClassificationElevation (feet)-10-15-20-25-30-35-40-45
With peat lenses (very stiff, wet)
Gray fine sand with silt (medium dense to dense, wet)
19A
19B
18 30
SP-SM
Sheet 3 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-4-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-25
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)80 Graphic LogGroupClassificationElevation (feet)-50
Groundwater observed during drilling atapproximately 9.6 feet below ground surfaceDriller added mud
29 26
Approximately 6 inches of topsoil
Brown silty fine to coarse sand with gravel (mediumdense, moist) (fill)
Gray sandy silt with sand lenses and organic matter(roots) (medium stiff, moist) (alluvium)
Gray silty fine sand (loose, moist)
Grades to very loose to loose, wet
Gray sandy silt with 6-inch layer of silty fine sand (softto medium stiff, wet)
With peat lenses (soft to medium stiff, wet)
With occasional wood debris (very stiff, wet)
Gray fine sand with silt and occasional wood debris(medium dense, wet)
Gray sandy silt with sand lenses and wood debris(medium stiff, wet)
1
2
3
4%F
5
6
7
8
9
6
0
15
15
18
18
18
18
28
7
6
4
4
4
24
5
TS
SM
ML
SM
ML
SM
ML
Notes:
81.5 BZ
LA Advance Drill Technologies,Inc.Hollow-stem Auger
Diedrich D50 drill rigDrillingEquipmentAutohammer140 (lbs) / 30 (in) Drop
WA State Plane NorthNAD83 (feet)47.494264-122.202968
30
LatitudeLongitude
Start TotalDepth (ft)
Logged By
Checked By
End
Surface Elevation (ft)Vertical Datum
Drilled
HammerData
SystemDatum
Driller DrillingMethod
See "Remarks" section for groundwater observed
8/1/20198/1/2019
Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on Locational Survey. Vertical approximated based on Topographic Survey.
Sheet 1 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-5-19
Logan Avenue N/N 8th Street Development
Figure A-26
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0
5
10
15
20
25
30
35 Graphic LogGroupClassificationElevation (feet)2520151050-5
Dark brown peat with silt lenses (medium stiff, moist)
Gray silty sand (medium dense, wet)
Gray fine sand with silt lenses (loose to mediumdense, wet)
Gray silt with peat lenses (medium stiff, wet)
Grades to medium stiff to stiff
Gray fine to medium sand with occasional wood debris(dense, wet)
Gray silt with sand lenses and wood debris (very stiff,wet)
Gray fine sand with silt (medium dense, wet)
Dark brown peat with interbedded silt lenses (stiff,moist)
Gray silt with sand (very stiff, wet)
Gray silty sand (medium dense, wet)
10
11A
11B
12
13
14
15
16A
16B
17
18A
18B
18
16
18
18
18
18
18
18
18
6
19
10
5
8
44
19
12
20
PT
SM
SP-SM
ML
SP-SM
ML
SP-SM
PT
ML
SM
Sheet 2 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-5-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-26
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35
40
45
50
55
60
65
70
75 Graphic LogGroupClassificationElevation (feet)-10-15-20-25-30-35-40-45
Gray sandy silt with occasional organic matter (roots)(very stiff, wet)
Gray silty fine sand (medium dense, wet)
19A
19B
18 25 ML
SM
Sheet 3 of 3Project Number:
Project Location:
Project:
Renton, Washington
23325-001-00
Log of Boring GEI-5-19 (continued)
Logan Avenue N/N 8th Street Development
Figure A-26
Date:9/11/19 Path:P:\23\23325001\GINT\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWREMARKS
MoistureContent (%)FinesContent (%)FIELD DATA
MATERIALDESCRIPTION
Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)80 Graphic LogGroupClassificationElevation (feet)-50
CPT-01
CPT Contractor: In Situ EngineeringCUSTOMER: GeoEngineersLOCATION: RentonJOB NUMBER: 23325-001-00
OPERATOR: Okbay/MayfieldCONE ID: DDG1263TEST DATE: 4/3/2018 8:10:21 AMPredrill: Backfill: 20% bentonite slurrySurface Patch:
Depth(ft)
Tip COR(tsf)
0 5000
10
20
30
40
50
60
70
80
90
F.Ratio(%)
0 12
Pore Pressure(psi)
-10 80
SBT FR(RC 1983)
1 sensitive fine grained 2 organic material 3 clay
4 silty clay to clay 5 clayey silt to silty clay 6 sandy silt to clayey silt
7 silty sand to sandy silt 8 sand to silty sand 9 sand
10 gravelly sand to sand 11 very stiff fine grained (*) 12 sand to clayey sand (*) *SBT/SPT CORRELATION: UBC-1983
0 12
SPT(blows/ft)
0 60
HOLE NUMBER: CPT-01
Depth 4.27ftRef*Arrival 8.48mSVelocity*
Depth 10.83ftRef 4.27ft Arrival 25.27mSVelocity 329.04ft/S
Depth 17.39ftRef 10.83ft Arrival 39.68mSVelocity 432.75ft/S
Depth 23.79ftRef 17.39ft Arrival 51.56mSVelocity 526.10ft/S
Depth 30.35ftRef 23.79ft Arrival 63.90mSVelocity 524.33ft/S
Depth 36.91ftRef 30.35ft Arrival 77.57mSVelocity 475.70ft/S
Depth 43.47ftRef 36.91ft Arrival 92.34mSVelocity 441.65ft/S
0 20 40 60 80 100 120 140 160
Depth 49.54ftRef 43.47ft Arrival 101.40mSVelocity 666.67ft/S
Time (mS)
Hammer to Rod String Distance (ft): 4.49* = Not Determined
CPT-02
CPT Contractor: In Situ EngineeringCUSTOMER: GeoEngineersLOCATION: RentonJOB NUMBER: 23325-001-00
OPERATOR: Okbay/MayfieldCONE ID: DDG1263TEST DATE: 4/3/2018 9:36:38 AMPredrill: Backfill: 20% bentonite slurrySurface Patch:
Depth(ft)
Tip COR(tsf)
0 5000
10
20
30
40
50
60
70
80
90
F.Ratio(%)
0 12
Pore Pressure(psi)
-10 80
SBT FR(RC 1983)
1 sensitive fine grained 2 organic material 3 clay
4 silty clay to clay 5 clayey silt to silty clay 6 sandy silt to clayey silt
7 silty sand to sandy silt 8 sand to silty sand 9 sand
10 gravelly sand to sand 11 very stiff fine grained (*) 12 sand to clayey sand (*) *SBT/SPT CORRELATION: UBC-1983
0 12
SPT(blows/ft)
0 60
HOLE NUMBER: CPT-02
Depth 4.10ftRef*Arrival 10.04mSVelocity*
Depth 10.50ftRef 4.10ft Arrival 15.74mSVelocity 935.66ft/S
Depth 16.73ftRef 10.50ft Arrival 32.93mSVelocity 343.59ft/S
Depth 22.97ftRef 16.73ft Arrival 46.01mSVelocity 464.35ft/S
Depth 29.69ftRef 22.97ft Arrival 61.44mSVelocity 429.61ft/S
Depth 36.09ftRef 29.69ft Arrival 73.20mSVelocity 539.10ft/S
0 20 40 60 80 100 120 140 160
Depth 42.65ftRef 36.09ft Arrival 88.28mSVelocity 432.38ft/S
Time (mS)
Hammer to Rod String Distance (ft): 4.49* = Not Determined
CPT-03
CPT Contractor: In Situ EngineeringCUSTOMER: GeoEngineersLOCATION: RentonJOB NUMBER: 23325-001-00
OPERATOR: Okbay/MayfieldCONE ID: DDG1263TEST DATE: 4/3/2018 10:22:04 AMPredrill: Backfill: 20% bentonite slurrySurface Patch:
Depth(ft)
Tip COR(tsf)
0 5000
10
20
30
40
50
60
70
80
90
F.Ratio(%)
0 12
Pore Pressure(psi)
-10 80
SBT FR(RC 1983)
1 sensitive fine grained 2 organic material 3 clay
4 silty clay to clay 5 clayey silt to silty clay 6 sandy silt to clayey silt
7 silty sand to sandy silt 8 sand to silty sand 9 sand
10 gravelly sand to sand 11 very stiff fine grained (*) 12 sand to clayey sand (*) *SBT/SPT CORRELATION: UBC-1983
0 12
SPT(blows/ft)
0 60
CPT-04
CPT Contractor: In Situ EngineeringCUSTOMER: GeoEngineersLOCATION: RentonJOB NUMBER: 23325-001-00
OPERATOR: Okbay/MayfieldCONE ID: DDG1263TEST DATE: 4/3/2018 10:56:04 AMPredrill: Backfill: 20% bentonite slurrySurface Patch:
Depth(ft)
Tip COR(tsf)
0 5000
10
20
30
40
50
60
70
80
90
F.Ratio(%)
0 12
Pore Pressure(psi)
-10 80
SBT FR(RC 1983)
1 sensitive fine grained 2 organic material 3 clay
4 silty clay to clay 5 clayey silt to silty clay 6 sandy silt to clayey silt
7 silty sand to sandy silt 8 sand to silty sand 9 sand
10 gravelly sand to sand 11 very stiff fine grained (*) 12 sand to clayey sand (*) *SBT/SPT CORRELATION: UBC-1983
0 12
SPT(blows/ft)
0 60
CPT-05
CPT Contractor: In Situ EngineeringCUSTOMER: GeoEngineersLOCATION: RentonJOB NUMBER: 23325-001-00
OPERATOR: Okbay/MayfieldCONE ID: DDG1263TEST DATE: 4/3/2018 11:22:27 AMPredrill: Backfill: 20% bentonite slurrySurface Patch:
Depth(ft)
Tip COR(tsf)
0 5000
10
20
30
40
50
60
70
80
90
F.Ratio(%)
0 12
Pore Pressure(psi)
-10 80
SBT FR(RC 1983)
1 sensitive fine grained 2 organic material 3 clay
4 silty clay to clay 5 clayey silt to silty clay 6 sandy silt to clayey silt
7 silty sand to sandy silt 8 sand to silty sand 9 sand
10 gravelly sand to sand 11 very stiff fine grained (*) 12 sand to clayey sand (*) *SBT/SPT CORRELATION: UBC-1983
0 12
SPT(blows/ft)
0 60
CPT-06
CPT Contractor: In Situ EngineeringCUSTOMER: GeoEngineersLOCATION: RentonJOB NUMBER: 23325-001-00
OPERATOR: Okbay/MayfieldCONE ID: DDG1263TEST DATE: 4/3/2018 12:41:18 PMPredrill: Backfill: 20% bentonite slurrySurface Patch:
Depth(ft)
Tip COR(tsf)
0 5000
10
20
30
40
50
60
70
80
90
F.Ratio(%)
0 12
Pore Pressure(psi)
-10 80
SBT FR(RC 1983)
1 sensitive fine grained 2 organic material 3 clay
4 silty clay to clay 5 clayey silt to silty clay 6 sandy silt to clayey silt
7 silty sand to sandy silt 8 sand to silty sand 9 sand
10 gravelly sand to sand 11 very stiff fine grained (*) 12 sand to clayey sand (*) *SBT/SPT CORRELATION: UBC-1983
0 12
SPT(blows/ft)
0 60
APPENDIX B Laboratory Testing
October 29, 2019 | Page B-1 File No. 23325-001-00
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 percent fines (material passing
the U.S. No. 200 sieve) and gradation test (sieve analysis). 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 general
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, were classified in general accordance with the
Unified Soil Classification System (USCS) and are presented in Figures B-1 through B-5, Sieve Analysis
Results.
Atterberg Limits
We completed Atterberg limits tests on selected fine-grained soil samples. We used the test results to
classify the soil as well as to evaluate index properties and consolidation characteristics. Liquid limits,
plastic limits and plasticity index were obtained in general accordance with ASTM Test Method D 4318.
Results of the Atterberg limits tests are summarized in Figures B-6 through B-10.
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
B-1
B-2
AB-1
AB-2
2.5
2.5
2.5
2.5
Silty fine to medium sand with gravel (SM)
Silty fine to coarse sand with gravel (SM)
Fine to coarse sand with silt and gravel (SP-SM)
Silty fine to medium sand with occasional gravel (SM)
Symbol
Moisture
(%)
15
10
9
9
3/8”3”1.5”#4 #10 #20 #40 #60 #1003/4”Figure B-1Sieve Analysis ResultsLogan Avenue N/N 8thStreet DevelopmentRenton, Washington023325-001-00 Date Exported: 04/18/18
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 wereperformed,and should not be interpretedas representativeof any other samples obtainedat othertimes,depths or locations,orgeneratedby separateoperations orprocesses.
Thegrain size analysis resultswereobtained ingeneral accordancewith ASTMD 6913.
#200
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
AB-3
OB-1
OB-3
OB-5
2.5
2.5
2.5
2.5
Silty fine to medium sand with occasional gravel (SM)
Fine to coarse gravel with silt and sand (GW-GM)
Fine to medium sand with silt and gravel (SW-SM)
Silty fine to medium sand with gravel (SM)
Symbol
Moisture
(%)
16
7
13
14
3/8”3”1.5”#4 #10 #20 #40 #60 #1003/4”Figure B-2Sieve Analysis ResultsLogan Avenue N/N 8thStreet DevelopmentRenton, Washington023325-001-00 Date Exported: 04/18/18
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 wereperformed,and should not be interpretedas representativeof any other samples obtainedat othertimes,depths or locations,orgeneratedby separateoperations orprocesses.
Thegrain size analysis resultswereobtained ingeneral accordancewith ASTMD 6913.
#200
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-2
PB-01
2.5
2.5
Fine to medium sand with silt and gravel (SP-SM)
Silty fine to coarse sand with gravel (SM)
Symbol
Moisture
(%)
13
11
3/8”3”1.5”#4 #10 #20 #40 #60 #1003/4”Figure B-3Sieve Analysis ResultsLogan Avenue N/N 8thStreet DevelopmentRenton, Washington023325-001-00 Date Exported: 04/18/18
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 wereperformed,and should not be interpretedas representativeof any other samples obtainedat othertimes,depths or locations,orgeneratedby separateoperations orprocesses.
Thegrain size analysis resultswereobtained ingeneral accordancewith ASTMD 6913.
#200
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
2”
SAND SILT OR CLAYCOBBLESGRAVEL
COARSE MEDIUM FINECOARSEFINE
Boring Number
Depth
(feet)Soil Description
GEI-3-19 7.5 Silty fine sand (SM)
Symbol
Moisture
(%)
32
3/8”3”1.5”#4 #10 #20 #40 #60 #1003/4”Figure B-4Sieve Analysis ResultsLogan Avenue N/N 8thStreet DevelopmentRenton, Washington23325-001-00 Date Exported: 8/13/19
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.GeoEngineers 17425 NE Union Hill Road Ste 250,Redmond,WA 98052
#2001”#140
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
2”
SAND SILT OR CLAYCOBBLESGRAVEL
COARSE MEDIUM FINECOARSEFINE
Boring Number
Depth
(feet)Soil Description
B-4-19 50 Fine to coarse gravel with sand (GP)
Symbol
Moisture
(%)
7
3/8”3”1.5”#4 #10 #20 #40 #60 #1003/4”Figure B-5Sieve Analysis ResultsLogan Avenue N/N 8thStreet DevelopmentRenton, Washington23325-001-00 Date Exported: 8/30/19
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.GeoEngineers 17425 NE Union Hill Road Ste 250,Redmond,WA 98052
#2001”#140
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 obtained at other times, depths or locations, or generated by separate operations or processes.
The liquid limit and plasticity index were obtained in general accordance with ASTM D 4318.
Figure B-6
Atterberg Limits Test Results
Logan Avenue N/N 8th Street Development
Renton, Washington
023325-001-00 Date Exported: 04/18/18Symbol
Boring
Number
Depth
(feet)
Moisture
Content
(%)
Liquid
Limit
(%)
Plasticity
Index
(%)Soil Description
B-1
B-1
B-2
B-2
7.5
27
7.5
15
40
48
35
38
35
47
35
117
5
10
5
33
Silt (ML)
Silt (ML)
Sandy silt (ML)
Sandy organic silt (OH)
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110 120PLASTICITY INDEX LIQUID LIMIT
PLASTICITY CHART
CL-ML ML or OL
CL or OL
OH or MH
CH or OH
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 obtained at other times, depths or locations, or generated by separate operations or processes.
The liquid limit and plasticity index were obtained in general accordance with ASTM D 4318.
Figure B-7
Atterberg Limits Test Results
Logan Avenue N/N 8th Street Development
Renton, Washington
023325-001-00 Date Exported: 04/18/18Symbol
Boring
Number
Depth
(feet)
Moisture
Content
(%)
Liquid
Limit
(%)
Plasticity
Index
(%)Soil Description
B-2
AB-2
OB-1
OB-3
25
7.5
20
7.5
61
39
37
32
78
37
NP
NP
15
7
NP
NP
Elastic silt (MH)
Sandy silt (ML)
Sandy silt (non-plastic) (ML)
Silty fine sand (non-plastic) (SM)
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100PLASTICITY INDEX LIQUID LIMIT
PLASTICITY CHART
CL-ML ML or OL
CL or OL
OH or MH
CH or OH
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 obtained at other times, depths or locations, or generated by separate operations or processes.
The liquid limit and plasticity index were obtained in general accordance with ASTM D 4318.
Figure B-8
Atterberg Limits Test Results
Logan Avenue N/N 8th Street Development
Renton, Washington
023325-001-00 Date Exported: 04/18/18Symbol
Boring
Number
Depth
(feet)
Moisture
Content
(%)
Liquid
Limit
(%)
Plasticity
Index
(%)Soil Description
OB-3
OB-4
OB-7
GEI-1
20
5
15
20
63
29
50
52
100
54
53
93
32
19
10
33
Silt with organic matter (ML)
Sandy elastic silt (MH)
Sandy elastic silt (MH)
Silt with peat lenses (ML)
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100PLASTICITY INDEX LIQUID LIMIT
PLASTICITY CHART
CL-ML ML or OL
CL or OL
OH or MH
CH or OH
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 obtained at other times, depths or locations, or generated by separate operations or processes.
The liquid limit and plasticity index were obtained in general accordance with ASTM D 4318.
Figure B-9
Atterberg Limits Test Results
Logan Avenue N/N 8th Street Development
Renton, Washington
023325-001-00 Date Exported: 04/18/18Symbol
Boring
Number
Depth
(feet)
Moisture
Content
(%)
Liquid
Limit
(%)
Plasticity
Index
(%)Soil Description
PB-01 15 100 120 33 Organic silt (OH)
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110 120PLASTICITY INDEX LIQUID LIMIT
PLASTICITY CHART
CL-ML ML or OL
CL or OL
OH or MH
CH or OH
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 obtained
at other times, depths or locations, or generated by separate operations or processes. The liquid limit and plasticity index were
obtained in general accordance with ASTM D 4318. GeoEngineers 17425 NE Union Hill Road Ste 250, Redmond, WA 98052 Figure B-10
Atterberg Limits Test Results
Logan Avenue N/N 8th Street Development
Renton, Washington
23325-001-00 Date Exported: 8/30/19Symbol
Boring
Number
Depth
(feet)
Moisture
Content
(%)
Liquid
Limit
(%)
Plasticity
Index
(%)Soil Description
B-1-19
B-4-19
B-4-19
40
30
65
48
60
79
54
63
94
16
14
28
Elastic silt with occasional sand (MH)
Elastic silt with occasional sand (MH)
Elastic silt with sand (MH)
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100PLASTICITY INDEX LIQUID LIMIT
PLASTICITY CHART
CL-ML ML or OL
CL or OL
OH or MH
CH or OH
APPENDIX C Site-Specific Seismic Response Analysis
October 29, 2019 | Page C-1 File No. 23325-001-00
APPENDIX C
SITE-SPECIFIC SEISMIC RESPONSE ANALYSIS
Nonlinear site response analyses were completed using the computer software FLAC (Fast Lagrangian
Analysis of Continua) developed by Itasca of Minneapolis, Minnesota. The purpose of the nonlinear site
response analyses is to evaluate site-specific soil amplification factors (AFs) and develop site-specific risk-
targeted maximum-considered earthquake (MCER) response spectra based on ASCE 7-10 (2010) using the
following approach:
1. Complete a site-specific probabilistic seismic hazard analyses (PSHA) to compute rock outcrop uniform
hazard spectra (UHS) for the maximum-considered earthquake (MCE) (2 percent probability of
exceedance in 50 years, 2,475-year return period). Rock outcrop conditions are defined as the Site
Class B/C boundary or Vs30=760 meters per second (m/sec).
2. Complete seismic hazard deaggregation for the 2,475-year event at the periods of interest and select
a suite of seven acceleration time histories that represent the contributing seismic sources to the total
hazard at the site.
3. Modify the frequency content of the time histories via spectral matching to match the input time history
response spectra to the target rock outcrop response spectra.
4. Develop shear wave velocity profiles and one-dimensional (1D) soil models based on the shear wave
velocity measurements obtained at the site and its vicinity and using subsurface information collected
from the geotechnical explorations completed at the site.
5. Complete nonlinear site response analyses to compute the soil response spectra at ground surface
and calculate site-specific soil AFs.
6. Evaluate maximum component adjustment (MCA) factors and risk coefficients per ASCE 7-10
Section 21.2.1.2.
7. Develop probabilistic MCER ground motions by multiplying the probabilistic MCE ground motions from
(1) by the site-specific soil AFs, MCA factors, and risk coefficients.
8. Develop deterministic MCER ground motions per ASCE 7-10 by evaluating the 84th percentile maximum
direction deterministic response spectrum including the MCA factors.
9. Develop the recommended site-specific MCER response spectrum by taking the lesser of the
probabilistic and deterministic MCER response spectra and comparing it to 80 percent of the ASCE 7-10
code-based response spectrum.
Rock Outcrop Uniform Hazard Spectrum
A site-specific PSHA was completed using the computer code Haz45.2 to develop the rock outcrop uniform
hazard spectrum. Relevant seismic sources based on the 2014 United States Geological Survey (USGS)
seismic source characterization (SSC) model were considered for the project. The 2014 USGS SSC model
contains seismic source characteristics and recurrence models developed by USGS for the 2014 update of
the National Seismic Hazard Maps (Petersen et al. 2014). The UHS for the 2,475-year event was computed
for rock outcrop conditions (i.e. Site Class B/C boundary, Vs30=760 m/sec). The suite of ground motion
models (GMMs) and corresponding weights that were used to complete the PSHA are presented in
Table C-1 below. Table C-2 presents the 2,475-year rock outcrop UHS.
October 29, 2019 | Page C-2 File No. 23325-001-00
TABLE C-1. GROUND MOTION MODELS AND WEIGHTS
Earthquake Source Ground Motion Prediction Equations Weight
Crustal
Abrahamson et al. (2014) [ASK14] 0.250
Boore et al. (2014) [BSSA14] 0.250
Campbell and Bozorgnia (2014) [CB14] 0.250
Chiou and Youngs (2014) [CY14] 0.250
Cascadia Subduction Zone
Benioff/Intraslab
Atkinson and Boore – Global Subduction (2003, 2008) [AB08-G] 0.167
Atkinson and Boore – Cascadia Subduction (2003, 2008) [AB08-C] 0.167
Zhao et al. (2006) [Z06] 0.333
BC Hydro – Global (Abrahamson et al. 2016) 0.234
BC Hydro – Cascadia (Abrahamson et al. 2016) 0.099
Cascadia Subduction Zone
Interface
Atkinson and Boore – Global Subduction (2003, 2008) 0.100
Zhao et al. (2006) 0.300
BC Hydro – Global (Abrahamson et al. 2016) 0.600
TABLE C-2. 2,475-YEAR UNIFORM HAZARD SPECTRUM (2,475-YEAR, VS30 = 760 M/SEC)
Period (sec) Target Rock Outcrop
0.01 0.651
0.05 0.962
0.075 1.256
0.1 1.486
0.2 1.507
0.3 1.198
0.4 0.989
0.5 0.820
0.75 0.578
1 0.439
2 0.200
3 0.113
4 0.074
5 0.051
Selection of Input Acceleration Time Histories
The seismic hazard deaggregation was performed at a spectral period (T) of 1.0 and 2.0 seconds to
evaluate the percent contribution of the various source-types to the uniform hazard associated with the
2,475-year earthquake event. The deaggregation results are presented in Table C-3. Based on the results,
four crustal events, one subduction-intraslab event, and two subduction-interface events were selected to
represent the 2,475-year event. Table C-4 summarizes the 2,475-year record suite used.
October 29, 2019 | Page C-3 File No. 23325-001-00
TABLE C-3. MCE SEISMIC HAZARD DEAGGREGATION (VS30=760 M/SEC)
Earthquake Source Percent Contribution to Hazard at
T=1.0 sec T=2.0 sec
Crustal 63 52
Subduction Zone – Intraslab 13 13
Subduction Zone – Interface 24 35
TABLE C-4. INPUT EARTHQUAKE TIME HISTORIES FOR 2,475-YEAR EVENT SITE RESPONSE ANALYSIS
Earthquake Type Mw Station Distance (km)
Tabas Iran, 1978 Crustal (Reverse) 7.4 Tabas 2.1
Loma Prieta, 1989 Crustal (Reverse
Oblique) 6.9 Saratoga – Aloha Ave 8.5
Niigata Japan, 2004 Crustal (Reverse) 6.6 NIGH11 8.9
Taiwan SMART1 (45), 1986 Crustal (Reverse) 7.3 SMART1 E02 51.4
El Salvador, 2001 Subduction Intraslab 7.6 Santa Tecia -
Maule, 2010 Subduction-Interface 8.8 Concepcion San Pedro (CCSP) 82.4
Tohoku, 2011 Subduction-Interface 9.0 Ujiie_TCGH12 299.0
Ground Motion Modification
The suites of input acceleration time histories were modified via spectral matching to match the target rock
outcrop 2,475-year response spectra from T=0.01 to 5.0 seconds. Spectral matching was completed
using RSPMatch09 (Fouad et al. 2012) based on the improved spectral matching approach proposed by
Al Atik, et al. (2010). The ground motions were processed with a Butterworth low pass filter to filter out
frequencies greater than 25 Hertz. The as-recorded and spectrally matched response spectra are
presented in Figures C-1 and C-2.
One-Dimensional Soil Models
Shear wave velocity (Vs) profiles were developed using measurements collected the site, and shear wave
velocity data for alluvium soils to account for the variability and uncertainty in the dynamic properties of the
soil. In-situ measurements were collected at two CPT locations (CPT-1 and CPT-2). Additionally, shear wave
velocity measurements for Alluvium soils were collected as part of the nearby Project Impact (Wong et
al. 2003).
We developed shear wave velocity profiles based on the in-situ measurements from CPTs, correlations with
SPT measurements from the borings completed at the site, and shear wave velocity data for alluvium soils
from a nearby study. Uncertainty in the shear wave velocity profile was incorporated into the analysis by
considering the difference between the CPT in-situ measurements and the shear wave velocity
measurements within alluvium soils, completed nearby. Two shear wave velocity profiles, lower bound (LB),
and upper bound (UB), were developed to capture the range of the measured shear wave velocity of the
soils to account for the uncertainty in the shear wave velocity of the subsurface soils encountered at the
October 29, 2019 | Page C-4 File No. 23325-001-00
site. The two profiles developed are presented in Figures C-3 and C-4, for depths extending to 100 feet
(shallow) and 400 feet (deep), respectively.
Table C-5 summarizes the soil type, layer depth, soil unit weight, plasticity index (PI), and shear modulus
reduction (G/Gmax) and damping curves used in the representative FLAC 1D soil model.
TABLE C-5. ONE-DIMENSIONAL SOIL MODEL
Soil Type Depth (feet)
Soil Unit
Weight (pcf) Plasticity Index G/Gmax and Damping Curves
Alluvium 1 0 to 10 100 0 Darendeli (2001)
Alluvium 2 10 to 50 110 0 Darendeli (2001)
Alluvium 3 50 to 60 120 0 Darendeli (2001)
Alluvium 4 60 to 170 125 0 Darendeli (2001)
Alluvium 5 170 to 400 125 0 Darendeli (2001)
Notes:
pcf – pounds per cubic foot
Site-Specific Amplification Factors
Site-specific soil AFs were computed for a 2,475-year event using the following approach:
1. Compute ground surface response spectra by propagating the suite of ground motions upward through
the LB and UB 1D soil models.
2. Compute lower bound and upper bound soil AFs as the average of the ratio of the ground surface
response spectra and the input rock outcrop response spectra for each ground motion suite.
3. Evaluate site-specific soil AFs as the weighted-average of the LB and UB soil AFs by assigning
0.5 weights to both LB and UB soil profiles.
Figures C-5 and C-6 present the individual and average soil AFs computed for the LB and UB profiles for
the 2,475-year event, respectively. Figure C-7 presents the recommended site-specific soil AFs. Figure C-8
presents the effect of site amplification by comparing the probabilistic MCE before (target rock outcrop
UHS) and after applying the recommended site-specific soil AFs (MCER).
Maximum Component Adjustment Factors and Risk Coefficients
Per ASCE 7-10, the probabilistic and deterministic MCER ground motions are to be taken in the direction of
maximum horizontal response. MCA factors are used to convert the geometric mean spectral ordinates to
spectral ordinates that correspond to the direction of maximum horizontal response. The MCA factors per
Shahi and Baker (2014) were used for this evaluation.
Risk coefficients are used to convert the probabilistic MCE ground motions (2 percent probability of
exceedance in 50 years) to MCER ground motions, which correspond to a 1 percent probability of collapse
in 50 years. Risk coefficients were calculated according to Section 21.2.1.2 of ASCE 7-10 using a MATLAB
script provided to us by Nico Luco of USGS. The risk coefficients were computed based on the seismic
hazard curves based on the average Vs30 calculated from the ground surface. Table C-6 presents the MCA
factors and the risk coefficients.
October 29, 2019 | Page C-5 File No. 23325-001-00
TABLE C-6. MAXIMUM COMPONENT ADJUSTMENT FACTORS AND RISK COEFFICIENTS
Period (sec) Maximum Component Adjustment Factor Risk Coefficients
0.010 1.19 0.96
0.050 1.19 0.96
0.075 1.19 0.96
0.100 1.19 0.96
0.200 1.21 0.98
0.300 1.22 0.99
0.400 1.23 0.97
0.500 1.23 0.95
0.750 1.24 0.93
1.000 1.24 0.92
2.000 1.24 0.89
3.000 1.25 0.91
4.000 1.26 0.89
5.000 1.26 0.89
Deterministic (MCER) Ground Motions
Deterministic MCER ground motions were evaluated per ASCE 7-10 Section 21.2.2. Figure C-9 presents the
development of the crustal deterministic (MCER) response spectrum. Based on our experience in the area,
crustal ground motions generally govern when computing deterministic response spectrum, hence only the
crustal deterministic response spectrum is presented.
The deterministic response spectrum was developed by computing the 84th percentile response spectrum
for rock outcrop conditions for the Seattle Fault (MW=7.2, RRUP=2.9 km) with the average Vs30=143 m/sec
using four equally-weighted NGA-West2 GMMs (ASK14, BSSA14, CB14, and CY14) (dashed gray lines
[individual GMMs] and solid red line [weighted average]). Lastly, MCA factors were applied to convert the
deterministic response spectrum (weighted average) to the direction of maximum horizontal response
(solid black line presented in Figure C-9).
Probabilistic (MCER) Ground Motions
Probabilistic MCER ground motions were evaluated per ASCE 7-10 Section 21.2.1. Probabilistic MCER
ground motions were computed by first multiplying the target rock outcrop UHS (Probabilistic MCE) by the
recommended MCA factors and risk coefficients. Lastly, soil AFs were applied to compute the probabilistic
MCER (dashed black line in Figure C-10).
Recommended Site-Specific MCER Response Spectrum
The recommended site-specific MCER response spectrum was developed by taking the lesser of the
probabilistic and deterministic MCER response spectra and comparing it to 80 percent of the ASCE 7-10
Site Class E MCER response spectrum (allowable code minimum) (Figure C-10). The recommended site-
specific MCER response spectrum is a smoothed version of the site-specific MCER response spectrum and
code spectrum. Table C-7 presents the recommended site-specific response spectrum.
October 29, 2019 | Page C-6 File No. 23325-001-00
TABLE C-7. RECOMMENDED SITE-SPECIFIC MCER RESPONSE SPECTRUM
Period (s) MCER Response Spectrum
0.01 0.45
0.05 0.71
0.075 0.79
0.10 0.86
0.20 1.04
0.30 1.04
0.40 1.04
0.50 1.04
0.75 1.04
1.00 1.04
2.00 0.68
3.00 0.40
4.00 0.26
5.00 0.21
0.01
0.1
1
10
0.01 0.1 15% Damped Spectral Acceleration, Sa (g)Period (seconds)
M7.35 Tabas_Iran L1 (Reverse) [C]
M6.9 Loma Prieta - Saratoga - Aloha Ave (Reverse
Oblique) [C]
M6.63 Niigata_Japan, NIGH11 (Reverse)
M7.3 Taiwan SMART1(45) - SMART1 E02
(Reverse) [C]
M9.0 Tohoku -Ujiie_TCGH12_EW [IF]
M8.8 Chile - Concepcion San Pedro_CCSP_NS
M7.6 El Salvador - Santa Tecia_ST_NS [IS]
2475-year UHS (Vs30=760 m/sec)
Average of 7 Input Ground Motions
As-recorded Response Spectra
2475-year Event
Logan Avenue N/N 8th Street Development
Renton, Washington
Figure C-1
Legend
Crustal Event
Interface Subduction Zone Event
IntraslabSubduction Zone Event
[C]
[IF]
[IS]Project: 23325-001-00 Executed: 05/16/2018
0.01
0.1
1
10
0.01 0.1 15% Damped Spectral Acceleration, Sa (g)Period (seconds)
M7.35 Tabas_Iran L1 (Reverse) [C]
M6.9 Loma Prieta - Saratoga - Aloha Ave (Reverse
Oblique) [C]
M6.63 Niigata_Japan, NIGH11 (Reverse)
M7.3 Taiwan SMART1(45) - SMART1 E02
(Reverse) [C]
M9.0 Tohoku -Ujiie_TCGH12_EW [IF]
M8.8 Chile - Concepcion San Pedro_CCSP_NS
M7.6 El Salvador - Santa Tecia_ST_NS [IS]
2475-year UHS (Vs30=760 m/sec)
Average of 7 Input Ground Motions
Spectrally Matched and Filtered
Response Spectra
Logan Avenue N/N 8th Street Development
Renton, Washington
Figure C-2
Legend
Crustal Event
Interface Subduction Zone Event
IntraslabSubduction Zone Event
[C]
[IF]
[IS]Project: 00694-040-00 Executed: 02/14/2018
0
10
20
30
40
50
60
70
80
90
100
0 500 1000 1500 2000 2500 3000
Depth (ft)Vs (ft/s)
B-1 Correlated Vs Data
B-2 Correlated Vs Data
CPT-1 Vs Data
CPT-2 Vs Data
Generalized Vs (LB) Profile
Generalized Vs (UB) Profile
Shear Wave Velocity Profiles - Shallow
Logan Avenue N/N 8th Street Development
Renton, Washington
Figure C-3
Project: 23325-001-00Exec uted: 05-16-2018
0
50
100
150
200
250
300
350
400
450
0 500 1000 1500 2000 2500 3000
Depth (ft)Vs (ft/s)
B-1 Correlated Vs Data
B-2 Correlated Vs Data
CPT-1 Vs Data
CPT-2 Vs Data
Generalized Vs (LB) Profile
Generalized Vs (UB) Profile
Shear Wave Velocity Profiles - Deep
Logan Avenue N/N 8th Street Development
Renton, Washington
Figure C-4
Project:23325-001-00 Executed: 05/16/2018
0
1
2
3
4
5
6
0.01 0.1 1Amplification Factor, Surface Sa/ Rock Outcrop SaPeriod (seconds)
M7.35 Tabas_Iran L1 (Reverse) [C]
M6.9 Loma Prieta - Saratoga - Aloha Ave (Reverse
Oblique) [C]
M6.63 Niigata_Japan, NIGH11 (Reverse)
M7.3 Taiwan SMART1(45) - SMART1 E02
(Reverse) [C]
M9.0 Tohoku -Ujiie_TCGH12_EW [IF]
M8.8 Chile - Concepcion San Pedro_CCSP_NS
M7.6 El Salvador - Santa Tecia_ST_NS [IS]
Average Amplification Factor, Lower Bound Profile
Soil Amplification Factor, Lower Bound Profile
2475-year Event
Logan Avenue N/N 8th Street Development
Renton, Washington
Figure C-5
Legend
Crustal Event
Interface Subduction Zone Event
IntraplateSubduction Zone Event (Bennioff)
[C]
[IF]
[IP]Project: 23325‐001‐00 Executed: 05/16/2018
0
1
2
3
4
5
6
0.01 0.1 1Amplification Factor, Surface Sa/ Rock Outcrop SaPeriod (seconds)
M7.35 Tabas_Iran L1 (Reverse) [C]
M6.9 Loma Prieta - Saratoga - Aloha Ave (Reverse
Oblique) [C]
M6.63 Niigata_Japan, NIGH11 (Reverse)
M7.3 Taiwan SMART1(45) - SMART1 E02 (Reverse)
[C]
M9.0 Tohoku -Ujiie_TCGH12_EW [IF]
M8.8 Chile - Concepcion San Pedro_CCSP_NS
M7.6 El Salvador - Santa Tecia_ST_NS [IS]
Average Amplification Factor, Upper Bound Profile
Soil Amplification Factors, Upper Bound Profile
2475-year Event
Logan Avenue N/N 8th Street Development
Renton, Washington
Figure C-6
Legend
Crustal Event
Interface Subduction Zone Event
IntraplateSubduction Zone Event (Bennioff)
[C]
[IF]
[IP]Project: 23325‐001‐00 Executed: 05/16/2018
0
1
2
3
4
5
6
0.01 0.1 1Amplification Factor, Surface Sa/ Rock Outcrop SaPeriod (seconds)
Average Amplification Factor, Lower Bound Profile
Average Amplification Factor, Upper Bound Profile
Recommended Weighted Average Amplification
Factor (Site Specific)
Soil Amplification Factors
Profile Comparison 2475-year Event
Logan Avenue N/N 8th Street Development
Renton, Washington
Figure C-7
Project: 23325‐001‐00 Executed: 05/16/2018
0.01
0.1
1
10
0.01 0.1 15% Damped Spectral Acceleration, Sa(g)Period (seconds)
Target Rock Outcrop UHS
Target Rock Outcrop UHS x Site Specific Soil
Amplification Factors
Probabilistic MCE
Response Spectrum Comparison
Logan Avenue N/N 8th Street Development
Renton, Washington
Figure C-8
Project: 23325-001-00 Executed: 05/16/2018
0.01
0.1
1
10
0.01 0.1 15% Damped Spectral Acceleration, Sa(g)Period (seconds)
ASK14 (No-Basin)
BSSA14 (No-Basin)
CB14 (No-Basin)
CY14 (No-Basin)
Weighted-Avg. Det (Crustal)
Weighted-Avg. Det + Basin Amplification Factors +
Max. Component Adj. Factors (Crustal)
Deterministic MCER Response Spectrum
(Seattle Fault, Mw=7.2, Rrup=2.9 km)
Logan Avenue N/N 8th Street Development
Renton, Washington
Figure C-9
Project: 23325-001-00 Executed: 5/16/2018
0.01
0.1
1
10
0.01 0.1 15% Damped Spectral Acceleration, Sa(g)Period (seconds)
ASCE 7-10 Site Class E MCEr
0.8 x ASCE 7-10 Site Class E MCEr
Deterministic (MCE) Response Spectrum
Site-Specific Probabilistic MCEr Response
Spectrum
Recommended Site-Specific MCEr Response
Spectrum
Recommended Site-Specific MCERResponse Spectrum
Logan Avenue N/N 8th Street Development
Renton, Washington
Figure C-10
Project: 23325-001-00 Executed: 5/16/2018
APPENDIX D Report Limitations and Guidelines for Use
October 29, 2019 | Page D-1 File No. 23325-001-00
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 ARCO Murray Design Build and other project team
members for the Logan Avenue North and North 8th Street development 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 Logan Avenue North and North 8th Street development 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 ASFE, Professional Firms Practicing in the Geosciences; www.asfe.org .
October 29, 2019 | Page D-2 File No. 23325-001-00
■ 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.
October 29, 2019 | Page D-3 File No. 23325-001-00
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.
October 29, 2019 | Page D-4 File No. 23325-001-00
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.