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GEOTECHNICAL ENGINEERING REPORT
PROPOSED RENTON RETAIL DEVELOPMENT
3751 EAST VALLEY ROAD
RENTON, WASHINGTON
Project No. 1217.01
February 7, 2014
Prepared for:
CenterPoint Integrated Solutions, LLC
Prepared by:
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
19023 36th Avenue W., Suite D
Lynnwood, WA 9803
ZGA
SITE
TABLE OF CONTENTS
Page
INTRODUCTION ........................................................................................................................................... 1
SITE DESCRIPTION ..................................................................................................................................... 1
PROJECT UNDERSTANDING .................................................................................................................... 2
DOCUMENT REVIEW .................................................................................................................................. 3
Existing Geotechnical Report .......................................................................................................................... 3
Act III Theater Plans ......................................................................................................................................... 4
Regional Geologic Publications ....................................................................................................................... 5
SUBSURFACE EXPLORATION .................................................................................................................. 5
SUBSURFACE CONDITIONS...................................................................................................................... 5
Soil Conditions ................................................................................................................................................. 5
Groundwater Conditions ................................................................................................................................. 7
CONCLUSIONS AND RECOMMENDATIONS ............................................................................................ 7
General Considerations ................................................................................................................................... 7
Seismic Design Considerations ........................................................................................................................ 8
Consolidation Settlement Considerations ..................................................................................................... 12
Ground Improvement and Deep Foundation Considerations ....................................................................... 14
Site Preparation ............................................................................................................................................. 16
Structural Fill Materials and Preparation ...................................................................................................... 18
Utility Trenches ............................................................................................................................................. 21
Temporary Shoring ........................................................................................................................................ 23
Temporary and Permanent Slopes ................................................................................................................ 23
Corrosion Considerations .............................................................................................................................. 24
Shallow Foundations ..................................................................................................................................... 24
Light Pole Foundations .................................................................................................................................. 26
Backfilled Permanent Retaining Walls .......................................................................................................... 26
On‐Grade Concrete Slabs .............................................................................................................................. 27
Drainage Considerations ............................................................................................................................... 28
Pavements ..................................................................................................................................................... 28
Asphalt Pavements ........................................................................................................................................ 29
Concrete Pavements ..................................................................................................................................... 30
CLOSURE ................................................................................................................................................... 30
FIGURES
Figure 1 – Vicinity Map
Figure 2 – Site and Exploration Plan ‐ Existing Condition
Figure 3 – Site and Exploration Plan ‐ Proposed Development
APPENDICES
Appendix A – ZGA Subsurface Exploration Procedures and Logs
Appendix B – ZGA Laboratory Testing Procedures and Results
Appendix C – LiquefyPro Summary Output Plates
Appendix D – Subsurface explorations and Laboratory Test Results by Others
Zipper Geo Associates, LLC
Proposed Renton Retail Development
Project No. 1217.01
February 7, 2014
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GEOTECHNICAL ENGINEERING REPORT ‐ DRAFT
PROPOSED RENTON RETAIL DEVELOPMENT
3751 EAST VALLEY ROAD
RENTON, WASHINGTON
Project No. 1217.01
February 7, 2014
INTRODUCTION
This report documents the surface and subsurface conditions encountered at the site and our
geotechnical engineering recommendations for the proposed Renton Retail Development. The project
description, site conditions, and our geotechnical conclusions and design recommendations are presented
in the text of this report. Supporting data including detailed exploration logs and field exploration
procedures, results of laboratory testing, and other supporting information are presented as appendices.
Our geotechnical engineering scope of services for the project included a literature review, site
reconnaissance, subsurface exploration, laboratory testing, geotechnical engineering analysis, and
preparation of this report. The subsurface evaluation consisted of completing twenty six exploratory
borings (designated B‐1 through B‐26) across the site. The borings extended to depths of approximately 20
to 86.5 feet below ground surface.
SITE DESCRIPTION
The project site consists of King County parcel 125360‐0030 totaling approximately 12.3 acres located at
3751 East Valley Road in Renton, Washington. At the time this report was prepared, the site was developed
with a Regal Cinema Theater and asphalt paved parking. Assessor records indicate the theater was
constructed in 1996 by Act III Theaters.
A vegetated stormwater management area with a stormwater pond is located along the west side of the
property. With the exception of the stormwater management area, the site is relatively flat and level with
adjoining roads with ground surface elevations typically ranging from 22 to 24 feet. Pavement grades
slope gently to stormwater catch basins, which appear to discharge to the western stormwater
management area.
The exterior walls of the theater building primarily consist of Concrete Masonry Unit (CMU) construction.
Open cracks on the order of 1/16 to 1/4 inch wide were observed in the elastomeric compound present in
the CMU wall construction control joints. In general, the cement mortar at inter‐block joints were free of
significant cracking. Along the west side of the theater building, up to 2 inches of differential settlement
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Proposed Renton Retail Development
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appears to have occurred, as the sidewalks adjoining the building have dropped. The asphalt pavement
appears to be in serviceable condition and free of significant cracking or rutting. Existing underground utilities
service the development and include storm water, sewer, gas, water, power, irrigation, and communications.
Site vegetation primarily consists of lawn near the theater building and ornamental shrubs and small trees in
planters and parking lot islands.
The site is bordered to the north and west by retail developments, to the south by retail developments and
SW 41st Street, and to the east by East Valley Road. A railroad spur approached the site from the west,
parallels a portion of the southern site boundary, and terminated about 60 feet south of the existing theater
building. The approximate location of the site is shown on the enclosed Vicinity Map, Figure 1. Existing Site
features are shown on the Site and Exploration Plan – Existing Condition, Figure 2.
PROJECT UNDERSTANDING
We understand the project will include construction of a new retail facility primarily located near the
central portion of the site with a carwash facility located near the east side of the stormwater
management area. The retail facility will include service, sales, and presentation buildings. The service
building overlaps onto the east footprint and entry of the existing theater. The sales and presentation
buildings are located east of the theater entry. The carwash facility is located in the current paved access
drive between the theater and the stormwater management area. The development includes
approximately 3.48 acres of customer/employee parking, 0.88 acres of sales/staging area secured by
gates, and 3.39 acres of sales display area parking. We understand that the existing stormwater
management facility will be utilized for this project without alteration. The enclosed Site and Exploration
Plan – Proposed Development, Figure 3, shows a generalized depiction of the proposed development. The
following table presents a more detailed description of individual development features and is based on
the Preliminary Site Plan SP‐06 dated November 21, 2013 and the June 18, 2013 Request for Proposal
document provided by CenterPoint Integrated Solutions, LLC, unless otherwise noted.
Development Feature DESCRIPTION
Building construction Tilt‐up or masonry structure with interior and perimeter columns and slab‐on‐
grade concrete floor.
Building foundations
Maximum column load: 120 kips
Maximum wall load: 4 kips per linear foot
Prototypical foundations bear around 3 feet below finished grade
Building finished floor
elevation
We understand that finished floor elevation will be within about 1 foot of
existing grade. (assumed)
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Development Feature DESCRIPTION
Floor slabs
Prototypical slab subgrade support modulus: 100 pci
3 kip rack post loads supported on 4”x4” base plates
8 kip vehicle load with 7”x7” contact area (2 kips per tire)
Floor slabs are moisture sensitive and require vapor retarder and capillary
break
Maximum allowable
settlement 1‐inch total and ½‐inch differential over a distance of 40 feet
Car lift loads 10 kip capacity with 2 kip self‐weight
Free‐standing retaining walls
Retaining walls are not included in the RFP document. However, we
understand that the project may include short retaining walls less than about
4 feet tall and that geotechnical design recommendations for retaining walls
have been requested.
Masonry wall Free standing masonry walls will be constructed around the WIP area.
Light pole foundations Prototypical light pole foundations are embedded about 7 to 9 feet below
finished grade.
Below grade areas None
Grading Cuts and fills on the order of 1 to 2 feet are assumed. A grading plan was not
available at the time this report was prepared.
Permanent Cut and fill slopes Assumed to be no steeper than 3H: 1V (Horizontal to Vertical).
Pavement
Asphalt concrete and Portland cement concrete pavement designed in
accordance with AASHTO design methods
20‐year pavement design period
Light duty: 7,500 18‐kip ESAL’s
Heavy duty: 75,000 18‐kip ESAL’s
Terminal serviceability Index: 2.0
DOCUMENT REVIEW
As part of our geotechnical evaluation, ZGA completed a review of an existing geotechnical report for the
site prepared for Act III Theaters, plans for the ACT III Theater, and regional geologic and hydrologic
publications. The geotechnical report and plans were provided to ZGA by CenterPoint Integrated
Solutions, LLC. A summary of our review is presented below.
Existing Geotechnical Report
ZGA completed a review of the following geotechnical report prepared for the site.
Geotechnical Report, Act III Theaters, SW 41st Street and East Valley Highway, Renton,
Washington, prepared by Terra Associates, Inc., dated January 30, 1996.
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February 7, 2014
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The report included five boring logs (borings B‐1 through B‐5) and laboratory data including a
consolidation test. Copies of the boring logs and laboratory test results from the referenced report are
enclosed in Appendix D. The approximate exploration locations presented in the referenced report are
shown on the Site and Exploration Plans, Figures 2 and 3, and should be considered approximate.
The 1996 report concluded that the primary concern for construction of the site is consolidation and
settlement of the building associated with new loads imposed on a two to four foot thick organic silt layer
underlying existing surficial fill soils. The report provided recommendations for three foundation support
options 1) a surcharge fill program within the building area and the use of conventional shallow spread
footings, 2) the excavation of the organic silt soils and their replacement with structural engineered fill
and the use of conventional shallow spread footings, and 3) the use of timber pile or augercast pile
foundation support.
Act III Theater Plans
ZGA completed a geotechnical review of the following plan set for the Act III Theater provided by
CenterPoint Integrated Solutions, LLC.
Act III Theaters, East Valley Cinema, Renton, Washington, 100% Issue, July 1, 1996, 10‐21‐1996
General Revision.
Structural Sheets S101, S102, and S103 indicate the use of conventional shallow spread foundations. The
Structural Notes on Sheet S103 indicate a design soil bearing pressure off 3,000 psf (dead plus live loads)
and reference the Geotechnical Report prepared by Terra Associates, Inc., dated January 30, 1996. The
notes indicate that foundations shall bear on undisturbed soil or approved structural fill. The plans and
notes do not indicate the use of deep foundations such a driven timber piles or augercast pile systems.
The referenced ACT III Theaters plan set did not include civil drawings either in the plan set or cover page
index and did not indicate if a surcharge fill program or foundation alignment over‐excavation and
replacement plan was implemented to limit anticipated consolidation settlement as discussed in the
January 30, 1996 Geotechnical Report prepared by Terra Associates, Inc.
In addition to the referenced ACT III Theaters plan set, ZGA completed a geotechnical review of
approximately 180 AutoCAD files for the Act III Theater provided by CenterPoint Integrated Solutions, LLC.
In general, the AutoCAD files appeared to be associated with the referenced ACT III Theaters plan set and
did not disclose additional information relative to foundation design and remedial measures that may
have been completed to limit anticipated consolidation settlements.
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Regional Geologic Publications
We assessed the geologic setting of the site and the surrounding vicinity by reviewing the following
regional publications.
Geologic Map of the Renton Quadrangle, Washington. United States Geologic Survey, GQ 405,
1965.
Liquefaction Susceptibility of the Des Moines and Renton 7.5‐minute Quadrangles, Washington.
Washington State Department of Natural Resources, Geologic Map GM‐41, 1994.
The project site is located in the Green River Valley about 1 mile east of the Green River. The valley is
characterized by intermittent near surface deposits of peat and deep deposits of alluvium on the order of
several hundred feet thick in the project area. Pleistocene glacial and non‐glacial deposits and Tertiary
sedimentary bedrock underlie the valley alluvium. The Geologic Map of the Renton Quadrangle,
Washington maps the site as being mantled by Quaternary lacustrine peat (Qlp) deposits. The lacustrine
peat is described as containing minor amounts of silt and clay, chiefly as basal beds, and a thin layer of
volcanic ash. The surrounding area is mapped as Quaternary alluvium (Qaw) deposited by the White and
Green Rivers. The alluvium is described as chiefly sand, silt, and clay containing curvilinear channel gravels
and thin peat lenses.
SUBSURFACE EXPLORATION
The subsurface exploration completed for this project included twenty six borings (B‐1 to B‐26) completed
across the site. Borings B‐9, B‐10, and B‐11 were advanced to depths ranging from about 64 to 86.5 feet
around the perimeter of the proposed retail building using mud‐rotary drilling methods. The remainder
of the borings were completed using hollow stem auger drilling methods within the building envelope and
surrounding development area and extended to depths of about 20 to 21½ feet. The approximate
exploration locations relative to existing site conditions are shown on the Site and Exploration Plan –
Existing Conditions, Figures 2. The approximate exploration locations relative to proposed development
features are shown on the Site and Exploration Plan – Proposed Development, Figures 3. Soils were
visually classified in general accordance with the Unified Soil Classification System. Descriptive logs of the
subsurface explorations and the procedures utilized in the subsurface exploration program are presented
in Appendix A. Generalized descriptions of the subsurface soil and groundwater conditions are presented
in the following sections, and laboratory testing procedures and results are presented in Appendix B.
SUBSURFACE CONDITIONS
Soil Conditions
The geotechnical borings completed for this project encountered asphalt pavement underlain by fill soils and
undisturbed native deposits. For the purposes of this report, soils encountered below the asphalt
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pavement have been divided into five primary deposits based on relative density/consistency, gradation,
and depositional characteristics. These deposits consist of a top down sequence of fill soils, lacustrine
organic silt and peat deposits, alluvial deposit, lacustrine elastic silt deposits, and estuarine deposits. A
generalized description of the asphalt and underlying 5 primary soil units is presented below.
Asphalt Pavement: Asphalt pavement was encountered in all 26 borings completed for this project. In
general, the asphalt in travel lanes ranged from about 5½ to 6 inches thick. Asphalt in general parking
areas typically ranged from 4 to 4½ inches thick with a few scattered locations up to about 5½ inches thick.
In general, the asphalt pavement was not underlain by a conventional crushed rock top course or base
course material and was typically constructed directly on fill soils described below.
Fill Soils: Import fill soils were encountered below the asphalt pavement and extended to a depth of about
5½ to 9½ feet below existing grade at the exploration locations. In general, the upper five to 6 feet of fill
consisted of medium dense to dense, moist, gravelly sand to sandy gravel with some silt. The fill
encountered below about 5 to 6 feet typically consisted of loose to medium dense, sandy gravel to gravelly
sand with silt. The lower relative density of the lower portion of the fill is likely due to poor compaction
associated with the presence of water during placement and/or the soft nature of the underlying native
soils.
Lacustrine Organic Silt and Peat Deposits: Interbedded organic silt and fine, fibrous peat deposits were
encountered below the existing fill soils in all 26 explorations. The interbedded organic silt and peat
ranged from about 5½ to 9½ feet below existing grade to a depth of about 7½ to 13½ feet below grade.
The thickness of the deposit ranged from about 1½ feet to 4½ feet thick with an average thickness of
about 3.4 feet. We visually estimated the organic silt to typically constitute about 60 to 70 percent of the
total deposit thickness. In general, the organic silt and peat were in a very soft to medium stiff condition.
Alluvial Deposits: Alluvial deposits were encountered below the lacustrine organic silt and peat deposits
in all 26 explorations and extended to a depth of about 32 to 33 feet below existing grade. In general, the
alluvial deposits consisted of loose to medium dense sand with variable silt content.
Lacustrine Clay and Silt Deposits: The 3 deeper mud‐rotary borings (B‐9 through B‐11) encountered a
layer of very soft, gray, elastic silt below the alluvium. The elastic silt layer was about 3 to 4 feet thick at
the exploration locations and extended from about 32 to 33 feet below grade to about 36 to 37 feet below
grade.
Estuarine Deposits: Borings B‐9 through B‐11 encountered estuarine deposits below the lacustrine clay
and silt. The estuarine deposits typically consisted of loose to dense sand with variable silt content and
trace shell fragments. The estuarine deposits extended to the total depth explored at 86.5 feet below
existing grade.
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Groundwater Conditions
Groundwater was encountered in all 26 borings at the time of exploration. Groundwater depths at the
time of exploration were inferred from observations of soil sample moisture conditions, the wetted
portion of sampling rods, and/or seepage from the boring sidewalls at the time of auger removal. In
general, groundwater depths ranged from about 5 to 12 feet below existing grade at the time of drilling,
with an average depth of about 7.5 feet. At five of the boring locations, our groundwater observations
indicated the presence of a perched water table at a depth of about 5 to 7 feet above the lacustrine
organic silt soils and a lower phreatic water table in the alluvial sand deposits at a depth of about 8 to 11
feet below existing grade.
To better characterized site groundwater conditions, the drilling auger was left in borings B‐6, B‐18, and
B‐23 for 20 to 30 minutes after reaching the planned boring depth of about 20 feet to function as a
temporary well casing. Groundwater was measured in borings B‐6, B‐18, and B‐23 at depths of 8.9, 9.6,
and 5 feet below existing grade, respectively.
Fluctuations in groundwater levels will likely occur due to seasonal variations in the amount of rainfall,
runoff and other factors not evident at the time the explorations were performed. Therefore,
groundwater levels during construction or at other times in the life of the structure may be higher than
indicated on the logs. The possibility of groundwater level fluctuations and perched water above the
lacustrine organic silt and peat deposits should be considered when developing the design and
construction plans for the project.
CONCLUSIONS AND RECOMMENDATIONS
General Considerations
Based on our subsurface exploration program and associated research, we conclude that the proposed
development is feasible from a geotechnical standpoint, contingent on proper design and construction
practices. The subsurface exploration completed for our evaluation encountered soils susceptible to
seismic induced liquefaction settlements and settlement associated with consolidation of fine‐grained
soils and peat under static loads as discussed below.
The liquefaction potential of the development was evaluated relative to seismic hazards resulting from
ground shaking associated with the Maximum Considered Earthquake Geometric Mean (MCEG) Peak
Ground Acceleration in accordance with the 2012 International Building Code (IBC). Based on our analysis,
we estimate total seismic settlements of approximately 6 to 10½ inches. We estimate differential seismic
settlements of approximately 3 to 5¼ inches over a horizontal distance of 40 feet.
We also completed an evaluation of static settlements associated with new building loads and new fill
that may be placed to raise site grades. Based on our evaluation, we estimate total primary settlement
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of about 2 to 3 inches associated with new foundation loads, caused by consolidation of organic silt and
peat below the existing fill. A grading plan was not available at the time this report was prepared.
However, we understand that significant alteration to site grades are not currently planned. To address
potential changes to site grades, we evaluated consolidation settlements associated with raising site
grades by 1 and 2 feet based on a moist unit weight of 130 pcf for new compacted structural fill. Based
on our evaluation, we estimate total primary settlements of about ½ to 1 inches associated with raising
site grade 1 to 2 feet, respectively. If grades are raised in the building envelope, these settlements would
be additive to the settlements presented for foundation loads. We estimate the time required to achieve
primary settlement to be about 3 to 5 weeks. Secondary consolidation would continue after primary
consolidation over the life of the development, but at a much slower rate. We estimate secondary
consolidation settlements on the order of 3 to 6 inches over 30 years.
Settlements resulting from the weight of new fill could impact the performance of settlement sensitive
improvements which are supported on‐grade. In general, we recommend that the grading plan be
developed to minimize the thickness of new fills, to the extent feasible. We recommend that new fill be
placed as early as possible in the construction schedule to allow the fill to settle before constructing on‐
grade facilities which are settlement sensitive. To the extent possible, it may desirable to allow sufficient
time for all of the fill settlements to occur before constructing on‐grade settlement sensitive facilities.
Based on our analyses, it is our opinion that the foundation and floor slab should be designed to mitigate
post‐construction settlement caused by both static consolidation of soft soils and liquefaction‐caused
settlement of deeper sands. We recommend that ground improvement methods such as GeoPiers or
stone columns be considered for this mitigation.
Discussions regarding seismic design, static consolidation settlement, and geotechnical engineering
recommendations for foundation systems and other earthwork related phases of the project are outlined
below. The recommendations contained in this report are based upon the results of field and laboratory
testing (which are presented in Appendices A and B), engineering analyses, and our current understanding
of the proposed project. ASTM and Washington State Department of Transportation (WSDOT)
specification codes cited herein respectively refer to the current manual published by the American
Society for Testing & Materials and the current edition of the Standard Specifications for Road, Bridge,
and Municipal Construction, (M41‐10).
Seismic Design Considerations
The tectonic setting of western Washington is dominated by the Cascadia Subduction Zone formed by the
Juan de Fuca plate subducting beneath the North American Plate. This setting leads to intraplate, crustal,
and interplate earthquake sources. Seismic hazards relate to risks of injury to people and damage to
property resulting from these three principle earthquake sources.
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The seismic performance of the development was evaluated relative to seismic hazards resulting from
ground shaking associated with the Maximum Considered Earthquake Geometric Mean (MCEG) Peak
Ground Acceleration and the Risk‐Targeted Maximum Considered Earthquake (MCER) Ground Motion
Response Acceleration in accordance with the 2012 International Building Code (IBC). Conformance to
the above criteria for seismic excitation does not constitute any kind of guarantee or assurance that
significant structural damage or ground failure will not occur if a maximum considered earthquake occurs.
The primary goal of the IBC seismic design procedure is to protect life and not to avoid all damage, since
such design may be economically prohibitive. Following a major earthquake, a building may be damaged
beyond repair, yet not collapse.
Ground Surface Rupture: Based on our review of the USGS Quaternary age fault database for Washington
State, the site is located about 4 miles south of the Seattle Fault zone. The Seattle Fault zone is a collective
term for a series of four or more east‐west trending reverse fault splays located near the southern margin
of the Seattle basin. The fault zone is about 2.5 to 4 miles wide (north‐south) and extends from the Kitsap
Peninsula near Hood Canal to the Sammamish Plateau east of Lake Sammamish. Most of the fault zone
is concealed by Holocene glacial and post glacial deposits, and is primarily mapped based on the location
of magnetic anomalies.
Geologic evidence indicates that ground surface rupture from movement on the Seattle Fault zone
occurred about 1,100 years ago. The geologic record suggests that potential future movement of the fault
zone may not occur for several thousand years (Johnson, et al., 1999, 2002). Given the relatively long
return period of the Seattle Fault zone and the location of the mapped fault zone relative to the project
site, it is our opinion that the risk of ground surface rupture at the site is low.
Landsliding: Based on the relatively level topography of the site and surrounding vicinity, it is our opinion
that the risk of earthquake‐induced landsliding is low.
Soil Liquefaction: Liquefaction is a phenomenon wherein saturated cohesionless soils build up excess
pore water pressures during earthquake loading. Liquefaction typically occurs in loose soils, but may
occur in denser soils if the ground shaking is sufficiently strong. ZGA completed a liquefaction analysis in
general accordance with Section 1803.5.12 of the 2012 IBC and Section 11.8.3 of ASCE 7‐10. Specifically,
our analysis used the following primary seismic ground motion parameters.
A Maximum Considered Earthquake Geometric Mean (MCEG) Peak Ground Acceleration of
0.579g, based on Figure 22‐7 of ASCE 7‐10.
A Modified Peak Ground Acceleration (PGAM) of 0.52g based on Site Class E, per Section 11.8.3 of
ASCR7‐10 (Site Class modification to MCEG without regard to liquefaction in accordance with
Sections 11.4.7 and 20.3.1 of ASCE 7‐10).
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A Geometric Mean Magnitude of 6.84 based on 2008 USGS National Seismic Hazard Mapping
Project deaggregation data for a seismic event with a 2% probability of exceedance in 50 years
(2,475 year return period) and a geometric mean peak ground acceleration of 0.585g.
Our liquefaction analysis was completed using the computer program LiquefyPro Version 5.8 which is
based on the simplified procedures originally developed by Seed and Idriss (1971). Our evaluation used a
fines content correction per Idriss and Seed (1997) and saturated soil settlement calculation procedure
per Ishihara and Yoshimine (1990). Our analysis was based on the three mud‐rotary borings (borings B‐9,
B‐10, and B‐11) completed within the building envelope and site specific laboratory tests. Borings B‐9 and
B‐10 extended 62½ to 64 feet below the ground surface. Boring B‐11 extended about 86½ feet below
grade. The approximate exploration locations are shown on the enclosed Site and Exploration Plans,
Figures 2 and 3.
Our analysis indicates the potential for liquefaction within the following depth intervals and soil deposits.
LiquefyPro summary output files for our analysis of the 2012 IBC design ground motions are enclosed in
Appendix C.
7 to 23 feet: potential liquefaction in the lower portion of the existing near surface fill soils and
underlying alluvial deposits.
36 to 53 feet: potential liquefaction in estuarine deposits.
63 to 86.5: potential liquefaction in estuarine deposits.
The simplified procedures for liquefaction analysis were developed from empirical evaluations of field
observations. Most of the case history data was collected from level to gently sloping terrain underlain by
Holocene‐age alluvial or fluvial sediment at depths less than 50 ft. Therefore, the simplified procedures
are most directly applicable to these site conditions. The potentially liquefiable zone encountered from
about 7 to 23 feet and 36 to 53 are generally suitable for evaluation by the simplified procedures, in our
opinion. Based on the subsurface data, the potentially liquefiable zone encountered from about 36 to 53
is underlain by about 10 feet of medium dense to very dense sand with a low potential for liquefaction
during the design earthquake. Based on historic records of relatively shallow liquefaction in the project
area and the low potential for liquefaction in the 10 foot zone of medium dense to very dense sand below
53 feet, it is our opinion that the potential for significant surface manifestation associated with potential
liquefaction and settlement within the soil zone located below 63 feet is low.
Liquefaction Settlement: Based on our analyses, we estimate a total seismic settlement of approximately
6 to 10½ inches. We estimate a differential seismic settlement of approximately 3 to 5¼ inches over a
horizontal distance of 40 feet.
Soil liquefaction may be expressed at the ground surface as sand boils, ground cracks, vertical settlements,
and lateral displacements. However, given the presence of non‐liquefiable soils located above the water
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table, surficial expression of soil liquefaction such as sand boils and ground cracking may not be observed
at the project site during a 2012 IBC seismic event.
If these levels of seismic induced liquefaction settlement are not acceptable, we recommend that
mitigative measures be considered as discussed in the Ground Improvement and Deep Foundations
Considerations section of this report.
Lateral Spread: Lateral spreading is a phenomenon in which soil deposits which underlie a site can
experience significant lateral displacements associated with the reduction in soil strength caused by soil
liquefaction. This phenomenon tends to occur most commonly at sites where the soil deposits can flow
toward a “free‐face”, such as a water body.
The Green River is located about 1 mile west of the site and has a bank height of about 15 feet based on
LIDAR data. We have assumed a free‐face height of about 30 feet based on an assumed channel depth of
15 feet. Given the geometry of the free‐face condition and the site distance from the free face, it is our
opinion that the potential for distress at the site from lateral spreading is low for the 2012 IBC design
seismic event.
IBC Seismic Design Parameters: Per the 2012 IBC seismic design procedures and ASCE 7‐10, the presence
of liquefiable soils requires a Site Class definition of F. However, through reference to Sections 11.4.7 and
20.3.1 of ASCE 7‐10, the 2012 IBC allows site coefficients Fa and Fv to be determined assuming that
liquefaction does not occur for structures with fundamental periods of vibration less than 0.5 seconds.
Based on the results of the field evaluation, Site Class E may be used to determine the values of Fa and Fv
in accordance with Sections 11.4.7 and 20.3.1 of ASCE 7‐10. Site Class E describes soils that are considered
soft with a shear wave velocity less than 600 feet per second, average Standard Penetration Test values
less than 15, and an undrained shear strength less than 1,000 psf. Seismic Site Class F may require seismic
(foundation) ties between isolated column footings, which should be determined by the structural
engineering design of the foundations.
Code Used Site Classification
2012 International Building Code (IBC) 1 F 2, 3
Ss Spectral Acceleration for a Short Period 1.413g (Site Class B)
S1 Spectral Acceleration for a 1‐Second Period 0.526g (site Class B)
Fa Site Coefficient for a Short Period 0.9 (Site Class E)
Fv Site Coefficient for a 1‐Second Period 2.4 (Site Class E)
SMS Maximum considered spectral response acceleration
for a Short Period 1.272g (Site Class E)
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Code Used Site Classification
SM1 Maximum considered spectral response acceleration
for a 1‐Second Period 1.263g (Site Class E)
SDS Five‐percent damped design spectral response
acceleration for a Short Period 0.848g (Site Class E)
SD1 Five‐percent damped design spectral response
acceleration for a 1‐Second Period 0.842g (Site Class E)
1. In general accordance with the 2012 International Building Code, Section 1613.3.2 and ASCE 7‐10, Chapter
20. IBC Site Class is based on the average characteristics of the upper 100 feet of the subsurface profile.
2. The borings completed for this study extended to a maximum depth of 86.5 feet below grade. ZGA therefore
determined the Site Class assuming that medium dense alluvial soils with an average n value of 15 extend to
100 feet as suggested by published geologic maps for the project area.
3. Per the 2012 International Building Code, Section 1613.3.2 and ASCE 7‐10, Chapter 20, any profile containing
soils vulnerable to potential failure or collapse under seismic loading such as liquefiable soils.
Consolidation Settlement Considerations
The previous section of this report addresses potential seismic settlements at the site associated with
seismic induced liquefaction. This section addresses static settlement associated with consolidation of
fine‐grained and organic rich soils encountered at the site.
The native organic silt and peat deposit encountered between about 5½ to 7½ and 7½ to 13½ in our
explorations will tend to consolidate in response to new loads imposed by building foundations and fill
used to raise site grades. The deeper lacustrine elastic silt deposit encountered from about 32 to 37 feet
will tend to consolidate in response to new loads imposed by fill used to raise site grades, but is not
anticipated to settle significantly in response to new foundation loads given the decrease in foundation
load stress with depth. Settlement of these fine‐grained and organic deposits will result from primary and
secondary consolidation, which are relatively slow processes.
We evaluated settlements associated with new foundation loads based on a 4 foot thick layer of organic
silt and peat located 7 feet below grade. We further assumed a column foundation depth of 3 feet below
grade, a maximum column load of 120 Kips, and an allowable soil bearing capacity of 2,500 psf to
proportion the column footing. Based on our evaluation, we estimate total primary settlements of about
2 to 3 inches associated with foundation loads as described above unless the site is surcharged prior to
foundation construction. It should be noted that the assumed maximum foundation load of 120 kips (as
presented in the owner’s 2013 Request for Proposal) includes live loads. We anticipate that consolidation
settlements calculated for dead loads only would be slightly lower than those presented above.
A grading plan was not available at the time this report was prepared. However, we understand that
significant alteration to site grades are not currently planned. To address potential changes to site grades,
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we evaluated consolidation settlements associated with raising site grades by 1 and 2 feet using a moist
unit weight of 130 pcf for new compacted structural fill. Based on our evaluation, we estimate total
primary settlements of about ½ to 1 inches associated with raising site grade 1 to 2 feet, respectively. If
grades are raised in the building area, these settlements would be additive to the settlements presented
above for foundation loads.
We estimate the time required to achieve 90 percent of the primary settlement to be about 3 to 5 weeks.
Secondary consolidation will continue after primary consolidation over the life of the development, but
at a much slower rate. We estimate secondary consolidation settlements on the order of 3 to 6 inches
over 30 years.
Settlements resulting from the weight of new fill could impact the performance of settlement sensitive
improvements which are supported on‐grade. In general, we recommend that the grading plan be
developed to minimize the thickness of new fills, to the extent feasible. We recommend that new fill be
placed as early as possible in the construction schedule to allow the fill to settle before constructing on‐
grade facilities which are settlement sensitive. To the extent possible, it may desirable to allow sufficient
time for all of the fill settlements to occur before constructing on‐grade settlement sensitive facilities.
Consolidation settlement can be mitigated using several commonly employed methods as outlined below.
Delayed Construction: Settlements associated with raising site grades are often mitigated by placing fills
and allowing primary settlements to substantially complete before progressing with the construction of
settlement sensitive site improvements. This method is not appropriate for settlement associated with
new building loads.
Preload and Surcharge Fill Programs: A preload can be used to mitigate settlements associated with new
building loads. A preload consists of temporary fill placed in the building area to load the compressible
soils and induce primary consolidation before the building is constructed. The extent and thickness of the
preload are determined based on the preload soil unit weight, design building loads, and anticipated levels
of consolidation settlement. A surcharge consists of addition temporary fill that can be placed above the
preload in building to speed the rate of consolidation and reduce the preload period, if required by the
project schedule. Zipper Geo associates is available to develop preload and surcharge programs for the
planed site development, at you request, once a grading plan and allowable settlement period have been
developed.
Ground Improvement and Deep Foundations: Ground improvements or deep foundations can be used to
mitigate consolidation settlements for proposed buildings. Deep foundations would not address potential
settlements associated with raising site grade outside of the building envelope and ground improvement
beyond the building area is typically cost prohibitive. When these options are used to mitigate building
settlements, delayed construction is typically employed to address potential settlements outside of the
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building envelope if grades are raised. Ground improvements or deep foundations are discussed in more
detail in the following section of this report.
Ground Improvement and Deep Foundation Considerations
Our analyses indicate the potential for seismic induced liquefaction settlement due to ground motions
associated with the 2012 IBC seismic Design event. The foundation recommendations presented in this
report assume that the levels of potential seismic settlement presented in the Seismic Design
Considerations section of this report are considered acceptable, and that the conventional spread footing
foundation system is designed to meet the Life Safety and Collapse Performance objectives of the 2012
IBC. If these levels of potential seismic settlement are not acceptable, we recommend that ground
improvement be considered to reduce total and differential settlements to acceptable levels.
Our analyses also indicate the potential for consolidation settlements associated with new building loads
as discussed in the Consolidation Settlement Considerations section of this report. Based on the allowable
total and differential settlements presented in the owners 2013 Request for Proposal, we anticipate that
ground improvement or deep foundations will likely be required to mitigate seismic settlements. We
anticipate that the use of ground improvement or deep foundations would also mitigate potential static
settlements in the building envelope associated with consolidation of the site fine‐grained and organic
rich soil layers. A general discussion regarding ground improvement and deep foundation options is
presented below.
Ground improvement is typically completed by a specialty contractor on a design build basis to meet
performance criteria (allowable total and differential settlements) established by the owner or structural
engineer. The contractor would use the data (boring logs and lab data) in this report as the basis for the
specific design. The cost of ground improvement is strongly affected by the lateral extent and depth of
treatment required by the performance criteria. For example, if ground improvement is limited to
reducing foundation settlement and interior slabs are allowed to settle under seismic conditions and
consolidation, then the area of improvement would be greatly reduced (limited to foundation alignments)
and result in a decreased cost. Alternatively, the entire building envelope could be improved to reduce
settlements for both foundations and interior slabs at a higher cost. ZGA is available to assist the owner
in the design‐build process if deemed necessary.
Ground improvement methods are somewhat proprietary and differ between contractors to some
degree. We have therefore generalized ground improvement and structural support methods that could
be considered for the site conditions in an effort to clarify the primary mitigation alternatives.
GeoPiers: GeoPiers are an intermediate depth ground improvement typically constructed by drilling a hole
in the ground then ramming gravel into the hole in lifts to generate a stiff stone column and densify the
soil between columns (provided the soil between the columns has a gradation which will allow for
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compaction). This system typically results in improved bearing capacity, sliding resistance, reduced static
settlement, and reduced potential for liquefaction within the treated soils. Potentially liquefiable soils
extend to depths of 53 feet at the site and consist of relatively clean, saturated sands which will tend to
cave during the conventional GeoPier drilling process. Therefore, GeoPiers do not appear to be the most
appropriate method of ground improvement for this site. However, GeoPier has recently developed
methods for construction below the water table that do not require drilling an open hole and it may be
advantageous to request a bid for comparison to other improvement methods typically considered better
suited to saturated sands, such as stone columns.
Stone Columns: Stone columns are typically constructed by lowering a vibratory stinger into the ground
to a depth determined necessary to achieve the performance criteria. Gravel is then introduced to the
tip of the stinger by top‐feed or bottom‐feed methods and compacted in place by the vibratory action of
the stinger head. Soils between the stone columns are densified through vibroflotation (liquefaction and
subsequent settlement and densification) provided the soil between the columns has a gradation which
will allow for vibratory densification. The result is a stiff aggregate column similar to a GeoPier. However,
this method does not require drilling an open hole as with GeoPiers and is well suited for saturated ground
conditions. Stone columns can also be constructed to greater depths than GeoPiers. As with GeoPiers,
stone columns typically result in improved bearing capacity, sliding resistance, reduced static settlement,
and a reduced potential for liquefaction within the treated soils. Based on the depth of the potentially
liquefiable zone, we anticipate that stone columns installed using vibroflotation methods could likely
reduce seismic settlement to generally acceptable levels.
Vibroflotation: Vibroflotation (also known as vibrocompaction) is similar to stone columns in that a
vibratory stinger is lowered into the soil to the design improvement depth and withdrawn. Ground
improvement comes from liquefaction and subsequent settlement and densification of the surrounding
soil. No aggregate is introduced into the ground. Vibroflotation is suitable for relatively clean sands below
the water table. No significant improvement is typically achieved above the ground water table. This
method may be applicable to reducing the potential for liquefaction induced settlement, but would likely
not result in improved subgrade foundation support conditions relative to static loads.
Structural Support: Deep foundation systems such as auger cast piles or driven steel piles could be
considered to limit potential seismic settlements. However, given the depth of potentially liquefiable
soils, anticipated high down drag forces on pile foundations, and costs associated with pile foundation
design and construction, it is our opinion that deep foundations are not a cost effective mitigation method
at this site.
Based on the site soil and groundwater conditions and prototypical building loads, we anticipate that
stone columns or Geopiers will likely be the most cost effect method of ground improvement to limit
static and seismic settlements to tolerable levels. ZGA completed a preliminary evaluation of stone
column and GeoPier ground improvement options to mitigate seismic settlements with local design build
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contractors Hayward Baker and GeoPier for the owner for a project in Puyallup, Washington with similar
prototypical development features and loads. For the Puyallup project, the contractors estimated that a
7 foot center‐to‐center pier spacing would be adequate to limit static and seismic settlements to a
preliminary performance criteria of less than ¾‐inch of differential settlement over a distance of 40 feet
provided by the project structural engineer.
Relative to ground improvement treatment depth for the Renton Retail project, our liquefaction analysis
indicates two primary liquefiable zones located about 7 to 23 feet below grade and about 36 to 53 feet
below grade. Compressible organic soils associated with estimated static settlements are located within
the upper zone of potential liquefaction (7 to 23 feet). A deeper zone of potential liquefaction is indicated
in our analyses below 63 feet, but the potential for significant surface manifestation associated with
potential liquefaction and settlement within the soil zone located below 63 feet is considered low, as
discussed in the Soil Liquefaction section of this report (page 10). We therefore recommend that minimum
ground improvement treatment depths of 25 feet and 55 feet be considered for this project. The owner
specified differential settlement performance criteria and the level of ground improvement developed by
the design build contractor’s improvement methods will control the ground improvement treatment
depth. A minimum treatment depth of 25 feet would likely result in a non‐liquefiable zone of soil below
the site improvements on the order of 35 feet thick and may be adequate to limit differential seismic
settlement to the performance criteria. If the design build contractor determines that a treatment depth
of 25 feet is not adequate to meet the performance criteria, deeper improvement to about 55 feet may
be required. For preliminary cost estimating purposes, we recommend that a center‐to‐center pier
spacing of 7 feet and treatment depths of both 25 feet and 55 feet be considered. ZGA is available to work
with local design‐build contractors to better define treatment configurations and costs, at your request.
Site Preparation
Existing Structure Removal: The site is currently developed with a relatively large theater and is services
by varies underground utilities. Foundation elements or other below grade structures, if encountered,
should be completely demolished and removed from the proposed development areas.
Existing Utility Removal: We recommend that all underground utilities within the proposed building pad
be completely removed. Utility pipes outside the building envelope could be abandoned in place,
provided they are fully grouted with controlled density fill (CDF) and the trench backfill is density tested
to verify that it meets the compaction levels presented in the project specifications. Localized excavations
made for removal of utilities or existing unsuitable trench backfill should be backfilled with structural fill
as outlined in the following section of this report.
Erosion Control Measures: Stripped surfaces and soil stockpiles are typically a source of runoff sediments.
We recommend that silt fences, berms, and/or swales be installed around the downslope side of stripped
areas and stockpiles in order to capture runoff water and sediment. If earthwork occurs during wet
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weather, we recommend that all stripped surfaces be covered with straw to reduce runoff erosion,
whereas soil stockpiles should be protected with anchored plastic sheeting.
Temporary Drainage: Stripping, excavation, grading, and subgrade preparation should be performed in a
manner and sequence that will provide drainage at all times and provide proper control of erosion. The
near surface site soils have a low to moderate fines (silt and clay) content and are considered moderately
susceptible to disturbance and erosion when wet. The site should be graded to prevent water from
ponding in construction areas and/or flowing into and/or over‐excavations. Exposed grades should be
crowned, sloped, and smooth‐drum rolled at the end of each day to facilitate drainage if inclement
weather is forecasted. Accumulated water must be removed from subgrades and work areas immediately
and prior to performing further work in the area. Equipment access may be limited and the amount of
soil rendered unfit for use as structural fill may be greatly increased if drainage efforts are not
accomplished in a timely manner. Successful drainage of saturated zones due to accumulations of surface
water would be moderately slow due to the moderate fines content of the surficial soils. Instead,
aeration, chemical treatment, or removal and replacement would be more expeditious.
Clearing and stripping: The majority of the site is surfaced with asphalt and concrete. Vegetation is limited
to patches of lawn near the existing theater and ornamental shrubs and small trees in planter areas and
parking lot islands. We therefore anticipate that clearing and stripping will generally be limited to less than
6 inches in landscape areas. We anticipate that isolated areas of deeper stripping will be required to
remove tree roots.
Subgrade Preparation: Once site preparation is complete, all areas that do not require over‐excavation
and are at design subgrade elevation or areas that will receive new structural fill should be compacted to
a firm and unyielding condition, and to achieve the recommended compaction level within the upper 12
inches of exposed subgrade soil. Some moisture conditioning of site soils may be required to achieve a
moisture content appropriate for compaction. This is generally within ±2 percent of the soils optimum
moisture content. Our laboratory testing indicates that, at the time our explorations were completed, in‐
situ moisture contents within the upper 2½ feet of the existing site fill soils ranged from about 4 to 10
percent. The optimum moisture content of a representative sample of the existing fill soils collect from
boring B‐5 was about 5.7 percent determined in accordance with the modified Proctor maximum dry
density test method (ASTM d 1557). As a result, we expect that some moisture conditioning of site soils
during construction may be required to achieve suitable moisture contents (plus or minus two percent of
optimum) for compaction in areas.
Earthwork should be completed during drier periods of the year when soil moisture content can be
controlled by aeration and drying. If earthwork or construction activities take place during extended
periods of wet weather, or if the in‐situ moisture conditions are elevated above the optimum moisture
content, the soils could become unstable or not be compactable. In the event the exposed subgrade
becomes unstable, yielding, or unable to be compacted due to high moisture conditions, we recommend
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that the materials be removed to a sufficient depth in order to develop stable subgrade soils that can be
compacted to the minimum recommended levels. The severity of construction problems will be
dependent, in part, on the precautions that are taken by the contractor to protect the subgrade soils.
Once compacted, subgrades should be evaluated through density testing and proof rolling with a loaded
dump truck or heavy rubber‐tired construction equipment weighing at least 20 tons to assess the
subgrade adequacy and to detect soft and/or yielding soils. In the event that compaction fails to meet
the specified criteria, the upper 12 inches of subgrade should be scarified and moisture conditioned as
necessary to obtain at least 95 percent of the maximum laboratory density (per ASTM D1557). Those soils
which are soft, yielding, or unable to be compacted to the specified criteria should be over‐excavated and
replaced with suitable material as recommended in the Structural Fill section of this report. As an
alternate to subgrade compaction during wet site conditions or wet weather, the upper 12 inches of
subgrade should be over‐excavated to a firm, non‐yielding and undisturbed condition and backfilled with
compacted imported structural fill consisting of free‐draining Gravel Borrow or crushed rock.
Alternatively, over optimum soils could be treated with cement as a method to stabilize and strengthen
soft, wet soils.
Where needed to protect stable subgrades, either inside or outside the building excavations, we
recommend using crushed rock or crushed recycled concrete. The thickness of the protective layer should
be determined at the time of construction and be based on the moisture condition of the soil and the
amount of anticipated traffic.
Freezing Conditions: If earthwork takes place during freezing conditions, all exposed subgrades should be
allowed to thaw and then be compacted prior to placing subsequent lifts of structural fill. Alternatively,
the frozen material could be stripped from the subgrade to expose unfrozen soil prior to placing
subsequent lifts of fill or foundation components. The frozen soil should not be reused as structural fill
until allowed to thaw and adjusted to the proper moisture content, which may not be possible during
winter months.
Structural Fill Materials and Preparation
Structural fill includes any material placed below foundations and pavement sections, within utility
trenches, and behind retaining walls. Prior to the placement of structural fill, all surfaces to receive fill
should be prepared as previously recommended in the Site Preparation section of this report.
Laboratory Testing: Representative samples of on‐site and imported soils to be used as structural fill
should be submitted for laboratory testing at least 4 days in advance of its intended use in order to
complete the necessary Proctor tests.
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Re‐Use of Site Soils as Structural Fill: It is our opinion that the existing granular fill soils typically
encountered within the upper 5½ to 9½ feet are suitable for reuse as general structural fill from a
compositional standpoint provided it is placed and compacted in accordance with the moisture content
and compaction recommendations presented in this report. The moisture content of the existing site fill
soils typically increased with depth and the bottom of the fill layer was saturated in some areas due to
perched groundwater above underlying native organic silt deposits. Selective drying of over‐optimum
moisture soils may be achieved by scarifying or windrowing surficial materials during extended periods of
dry weather. Soils which are dry of optimum may be moistened through the application of water and
thorough blending to facilitate a uniform moisture distribution in the soil prior to compaction.
The native site soils encountered below the existing fill at depths between about 5½ to 9½ feet and 7½ to
13½ below existing grade consist of wet to saturated, soft organic silt and peat. These organic soils are
not suitable for reuse as structural fill and should be used in landscape areas or removed from the site.
The native alluvial soils below the organic silt and peat typically consist of saturated sand with variable silt
content. These soils are considered acceptable for reuse as structural sill from a compositional
standpoint, but will be very difficult to adequately compact due to their saturated nature and moderate
to high fines content. Extensive draining of these soils after excavation and subsequent aeration would
likely be required. For planning and cost estimating purposes, we recommend that these soils not be
considered for reuse as structural fill.
We recommend that site soils used as structural fill have less than 4 percent organics by weight and have
no woody debris greater than ½ inch in diameter. We recommend that all pieces of organic material
greater than ½ inch in diameter be picked out of the fill before it is compacted. Any organic‐rich soil
derived from earthwork activities should be utilized in landscape areas or wasted from the site.
Imported Structural Fill: Imported structural fill may be required due to weather or other reasons. The
appropriate type of imported structural fill will depend on weather conditions. During extended periods
of dry weather, we recommend imported fill meet the requirements of Common Borrow as specified in
Section 9‐03.14(3) of the 2012 Washington State Department of Transportation, Standard Specifications
for Road, Bridge, and Municipal Construction (WSDOT Standard Specifications). During wet weather,
higher‐quality structural fill might be required, as Common Borrow may contain sufficient fines to be
moisture sensitive. During wet weather we recommend that imported structural fill meet the
requirements of Gravel Borrow as specified in Section 9‐03.14(1) of the WSDOT Standard Specifications.
Retaining Wall Backfill: Retaining walls should include a drainage fill zone extending at least two feet back
from the back face of wall for the entire wall height. The drainage fill should meet the requirements of
Gravel Backfill for Walls as specified in Section 9‐03.12(2) of the WSDOT Standard Specifications.
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Structural Fill below Foundations: Crushed Rock Base Course meeting the requirements of Section 9‐
03.9(3) of the WSDOT Standard Specifications is recommended.
Pavement Subgrades: Any structural fill used within the upper one foot below pavement sections should
have a minimum California Bearing Ratio (CBR) of 20 percent when compacted to a minimum of 95
percent of the modified Proctor maximum dry density. A CBR value of 20 is representative of the soils
encountered at the site and has been used to develop our pavement section recommendations. This has
been assumed for the pavement design recommendations presented subsequently in this report.
Moisture Content: The suitability of soil for use as structural fill will depend on the time of year, the
moisture content of the soil, and the fines content (that portion passing the U.S. No. 200 sieve) of the soil.
As the amount of fines increases, the soil becomes increasingly sensitive to small changes in moisture
content. Soils containing more than about 5 percent fines (such as most of the on‐site soils) cannot be
consistently compacted to the appropriate levels when the moisture content is more than approximately
2 percent above or below the optimum moisture content (per ASTM D1557). Optimum moisture content
is that moisture content which results in the greatest compacted dry density with a specified compactive
effort.
Fill Placement: Structural fill should be placed in horizontal lifts not exceeding 10 inches in loose thickness.
Each lift of fill should be compacted using compaction equipment suitable for the soil type and lift
thickness. Each lift of fill should be compacted to the minimum levels recommended below based on the
maximum laboratory dry density as determined by the ASTM D1557 Modified Proctor Compaction Test.
Moisture content of fill at the time of placement should be within plus or minus 2 percent of optimum
moisture content for compaction as determined by the ASTM D1557 test method.
Compaction Criteria: Our recommendations for soil compaction are summarized in the following table.
Structural fill for roadways and utility trenches in municipal rights‐of‐way should be placed and compacted
in accordance with the jurisdiction codes and standards. We recommend that a geotechnical engineer be
present during grading so that an adequate number of density tests may be conducted as structural fill
placement occurs. In this way, the adequacy of the earthwork may be evaluated as it proceeds.
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RECOMMENDED SOIL COMPACTION LEVELS
Location Minimum Percent Compaction*
All fill below building floor slabs and foundations 95
Upper 2 feet of fill below floor slabs and pavements 95
Pavement fill below two feet 90
Retaining wall backfill less than 3 feet from wall 90
Retaining wall backfill more than 3 feet from wall 95
Upper two feet of utility trench backfill 95
Utility trenches below two feet 90
Landscape Areas 90
* ASTM D1557 Modified Proctor Maximum Dry Density
Placing Fill on Slopes: Permanent fill placed on slopes steeper than 5H: 1V (Horizontal: Vertical) should
be keyed and benched into natural soils of the underlying slope. We recommend that the base downslope
key be cut into undisturbed native soil. The key slot should be at least 8 feet wide and 3 feet deep. The
hillside benches cut into the native soil should be at least 4 feet in width. The face of the embankment
should be compacted to the same relative compaction as the body of the fill. This may be accomplished
by over‐building the embankment and cutting back to the compacted core. Alternatively, the surface of
the slope may be compacted as it is built, or upon completion of the embankment fill placement.
Utility Trenches
We recommend that utility trenching conform to all applicable federal, state, and local regulations, such
as OSHA and WISHA, for open excavations. Trench excavation safety guidelines are presented in WAC
Chapter 296‐155 and WISHA RCW Chapter 49.17. Municipal utilities such as water, sanitary sewer, and
stormwater should be installed in accordance with City of Renton standard plans and specification, if
applicable.
Trench Dewatering: Groundwater was encountered in all 26 borings at the time of exploration.
Groundwater depths ranged from about 5 to 12 feet below existing grade at the time of drilling, with an
average depth of about 7.5 feet. At five of the boring locations, our groundwater observations indicated
the presence of a perched water table at a depth of about 5 to 7 feet above the lacustrine organic silt soils
and a lower phreatic water table in the alluvial sand deposits at a depth of about 8 to 11 feet below
existing grade. Groundwater was measured in borings B‐6, B‐18, and B‐23 at depths of 8.9, 9.6, and 5 feet
below existing grade about 20 to 30 minutes after drilling, respectively.
Excavations for utilities and underground structures may extend into perched groundwater zones and the
groundwater table, depending on the depth of excavation, and should be expected to encounter some
water seepage. The amount of seepage will likely be a function of the lateral extent of the excavation and
how long the excavations remain open. The type and extent of dewatering measures will be a function
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of the groundwater conditions at the time of construction. Temporary systems could include sumps and
pumps, wellpoints, or pumped wells.
Depending on the season of the work, groundwater seepage elevations may be higher than that
encountered in our borings. At times, seepage could be heavy enough to require flattening the sidewalls
of excavations to reduce the risk of caving. Some caving of utility trench sidewalls should be anticipated
in association with groundwater seepage. We recommend that any excavations within groundwater
seepage zones be undertaken only when suitable dewatering equipment and temporary excavation
shoring are available, or where space is available to flatten the sidewalls. If dewatering becomes
necessary, it should be designed and maintained by the contractor. The appropriate type of dewatering
system should be determined by the contractor based on the conditions encountered.
Utility Subgrade Preparation: We recommend that all utility subgrades be firm and unyielding and free of
all soils that are loose, disturbed, or pumping. Such soils should be removed and replaced, if necessary.
All structural fill used to replace over‐excavated soils should be compacted as recommended in the
Structural Fill section of this report. If utility foundation soils are soft, we recommend that they be over‐
excavated 12 inches and replaced with crushed rock.
Structures such as manholes and catch basins which extend into soft soils should be underlain by at least
12 inches of crushed gravel fill compacted to at least 90 percent of the modified Proctor maximum dry
density. This granular material could consist of crushed rock, quarry spalls, or coarse crushed concrete.
Alternatively, quarry spalls or pea gravel could be used until above the water level. It may be necessary
to place a geotextile fabric over the native subgrade soils if they are too soft, to provide a separation
between the bedding and subgrade soils.
Bedding: We recommend that a minimum of 4 inches of bedding material be placed above and below all
utilities or in general accordance with the utility manufacturer’s recommendations and local ordinances.
We recommend that pipe bedding consist of Gravel Backfill for Pipe Zone Bedding as specified in Section
9‐03.12(3) of the WSDOT Standard Specifications. All trenches should be wide enough to allow for
compaction around the haunches of the pipe, or material such as pea gravel should be used below the
spring line of the pipes to eliminate the need for mechanical compaction in this portion of the trenches.
If water is encountered in the excavations, it should be removed prior to fill placement.
Trench Backfill: Materials, placement and compaction of utility trench backfill should be in accordance
with the recommendations presented in the Structural Fill section of this report. In our opinion, the initial
lift thickness should not exceed one foot unless recommended by the manufacturer to protect utilities
from damage by compacting equipment. Light, hand operated compaction equipment may be utilized
directly above utilities if damage resulting from heavier compaction equipment is of concern.
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Temporary Shoring
We recommend that temporary shoring systems be used where excavations will be located adjacent to
property lines, roadways or utilities, and might result in ground loss and damage to these facilities. A
trench box is one type of support system which might be used. The zone between the trench box and the
excavation face should be backfilled as necessary to limit ground movements. As an alternate, braced or
unbraced shoring of various types could be considered. We anticipate that some form of temporary
shoring system may be needed for utility installations, depending on their location and depth.
The lateral soil pressures acting on temporary excavation support systems will depend on the ground
surface configuration adjacent to the trench, and the amount of lateral movement which can occur as the
excavation is made. For support systems that are free to yield at the top at least one‐thousandth of the
height of the excavation, soil pressures will be less than if movements are limited by such factors as wall
stiffness or bracing.
We recommend that yielding systems be designed using equivalent fluid densities of 35 and 85 pounds
per cubic foot (pcf) for horizontal ground surfaces and ground surfaces inclined at 1.5H: 1V above the
horizontal, respectively. For non‐yielding systems, we recommend that the shoring be designed for a
uniform lateral pressure of 25H in pounds per square foot (psf), where H is the depth of the planned
excavation in feet below a level ground surface. Similarly, for a ground surface inclined at 1.5H: 1V, we
recommend that non‐yielding shoring be designed for a uniform lateral pressure of 55H.
The above recommended lateral soil pressures are based on a fully drained condition and do not include
the effects of hydrostatic water pressures. In addition, the above values do not include the effects of
surcharges (e.g., equipment loads, storage loads, traffic loads, or other surface loading). Hydrostatic
water pressures and surcharge effects should be considered as appropriate.
Temporary and Permanent Slopes
Temporary excavation slope stability is a function of many factors, including:
The presence and abundance of groundwater;
The type and density of the various soil strata;
The depth of cut;
Surcharge loadings adjacent to the excavation; and
The length of time the excavation remains open.
As the cut is deepened, or as the length of time an excavation is open, the likelihood of bank failure increases;
therefore, maintenance of safe slopes and worker safety should remain the responsibility of the contractor,
who is present at the site, able to observe changes in the soil conditions, and monitor the performance of
the excavation.
Zipper Geo Associates, LLC
Proposed Renton Retail Development
Project No. 1217.01
February 7, 2014
Page 24
It is exceedingly difficult under the variable circumstances to pre‐establish a safe and “maintenance‐free”
temporary cut slope angle. Therefore, it should be the responsibility of the contractor to maintain safe
temporary slope configurations since the contractor is continuously at the job site, able to observe the
nature and condition of the cut slopes, and able to monitor the subsurface materials and groundwater
conditions encountered. Unsupported vertical slopes or cuts deeper than 4 feet are not recommended if
worker access is necessary. The cuts should be adequately sloped, shored, or supported to prevent injury
to personnel from local sloughing and spalling. The excavation should conform to applicable Federal,
State, and Local regulations.
According to Chapter 296‐155 of the Washington Administrative Code (WAC), the contractor should make
a determination of excavation side slopes based on classification of soils encountered at the time of
excavation. Temporary cuts may need to be constructed at flatter angles based upon the soil moisture
and groundwater conditions at the time of construction. Adjustments to the slope angles should be
determined by the contractor at that time.
We recommend that all permanent cut or fill slopes constructed in native soils be designed at a 2H: 1V
(Horizontal: Vertical) inclination or flatter. All permanent cut and fill slopes should be adequately
protected from erosion both temporarily and permanently.
If the slopes are exposed to prolonged rainfall before vegetation becomes established, the surficial soils
will be prone to erosion and possible shallow sloughing. We recommend covering permanent slopes with
a rolled erosion protection material, such as Jute matting or Curlex II, if vegetation has not been
established by the regional wet season (typically November through May).
Corrosion Considerations
The near surface soils encountered within anticipated foundation depths are considered to be very slightly
corrosive to concrete features. Soils in the vicinity of the project site are not typically associated with high
sulfate contents. As such, the relative degree of sulfate attack would be considered negligible and ASTM
Type I/II Portland cement is suitable for all concrete below and at grade.
Shallow Foundations
Our analyses indicate the potential for liquefaction induced settlement due to ground motions associated
with the 2012 IBC design seismic event. Our analyses also indicate the potential for static settlements
associated with new building loads due to consolidation of fine‐grained soils and peat deposits at depth
as discussed in the Consolidation Settlement Considerations of this report. The foundation
recommendations presented below assume that potential seismic settlements due to liquefaction and
static consolidation settlements are mitigated through ground improvement within the building envelope.
Foundations for other structures outside the building pads will be subject to post‐construction
settlements as described within this report, unless ground improvement is completed.
Zipper Geo Associates, LLC
Proposed Renton Retail Development
Project No. 1217.01
February 7, 2014
Page 25
Based on our analyses, conventional spread footings designed as outlined above will provide adequate
support for the proposed building, retaining walls, and free standing CMU walls near the WIP area
provided that the foundation subgrades are properly prepared.
Foundation Subgrade Support: We anticipate that foundation subgrade soils at foundations depths of 1.5
to 3 feet will generally consist of existing fill consisting of medium dense to dense sandy gravel to gravelly
sand with silt. It is our opinion that foundation support for the proposed structure may be obtained from
either the medium dense to dense existing granular fill soils or from new engineered fill placed and
compacted in accordance with the recommendations provided in this report. The upper one‐foot of
foundation subgrades should be moisture conditioned, as necessary, and compacted to a firm and non‐
yielding condition and to at least 95 percent of the modified Proctor maximum dry density per ASTM:D‐
1557.
If loose subgrade soils are encountered and they cannot be compacted to the specified degree due to high
moisture content, we recommend that they be removed and replaced with structural fill consisting of
Crushed Rock Base Course meeting the requirements of WSDOT Section 9‐03.9(3). The zone of structural
fill should extend beyond the edge of foundation elements a distance equal to its thickness in order to
provide a 1H: 1V bearing splay through the working pad. The crushed rock should be placed above
compacted native subgrade prepared as recommended in the Site Preparation section of this report and
compacted to a firm and non‐yielding condition and to at least 95 percent of the modified Proctor
maximum dry density per ASTM:D‐1557
Allowable Bearing Pressure: Continuous and isolated column footings bearing on structural fill placed and
compacted in accordance with this report, or suitable native soils compacted as recommended, may be
designed for a maximum allowable, net, bearing capacity of 2,500 psf. A one‐third increase of the bearing
pressure may be used for short‐term transient loads such as wind and seismic forces. The above‐
recommended allowable bearing pressure includes a 3.0 factor of safety.
Shallow Foundation Depth and Width: For frost protection, the bottom of all exterior footings should
bear at least 18 inches below the lowest adjacent outside grade, whereas the bottoms of interior footings
should bear at least 12 inches below the surrounding slab surface level. We recommend that all
continuous wall and isolated column footings be at least 12 and 24 inches wide, respectively.
Lateral Resistance: We recommend using allowable base friction and passive earth values of 0.45 and 250
pcf equivalent fluid pressure (triangular distribution), respectively, which incorporate a factor of safety of
1.5. We recommend that passive resistance be neglected in the upper 18 inches of embedment.
Estimated Settlement: Assuming the foundation subgrade soils are prepared in accordance with
recommendations presented herein and that seismic settlements and static consolidation settlements
Zipper Geo Associates, LLC
Proposed Renton Retail Development
Project No. 1217.01
February 7, 2014
Page 26
have been addressed though ground improvement or preloading, total and differential settlements will
be controlled by the extent and details of the ground improvement. If ground improvement and/or
preloading have not been completed, static and seismic settlements would approach the levels outlined
in the Seismic Design Considerations and Consolidation Settlement Considerations section of this report.
Light Pole Foundations
We understand that the project will include concrete cast‐in‐place light pile foundations with a
prototypical embedment depth of around 7 to 9 feet. The site is mantled by about 5½ to 9½ feet of fill
consisting of sandy gravel to gravelly sand with some silt. In general, the upper 5 feet of the fill is medium
dense to dense, while those portions of the fill bellow about 5 feet are typically loose. The fill is underlain
by very soft to medium stiff organic silt and peat which typically ranged from about 5½ to 9½ feet below
existing grade to a depth of about 7½ to 13½ feet below grade. The thickness of the organic silt and peat
deposit ranged from about 1½ feet to 4½ feet thick with an average thickness of about 3.4 feet. The
organic silt and peat deposits are underlain by loose to medium dense alluvial sand deposits.
Section 1807.3.2 of the 2012 International Building Code (IBC) provides design procedures for restrained
an unrestrained pole or post foundations. Non‐constrained and constrained pole or post foundations
embedded in the existing fill soils or new compacted structural fill may be designed for a maximum
allowable lateral soil‐bearing capacity of 150 psf per foot of embedment below finished grade to a depth
of 5 feet in accordance with Table 1806.2 of the 2012 IBC. We recommend that lateral soil bearing
capacity be neglected below 5 feet due to the soft, compressible nature of the organic silt and peat
deposits. Vertical foundation support may be provided by skin friction within the upper 5 feet of the
existing fill deposits. We recommend an allowable skin friction value of 250 psf. If skin friction is not
adequate to support the foundations, end bearing may be utilized as outlined below.
Based on the subsurface conditions encountered in the explorations, we anticipate that the prototypical
light pole foundation excavations will likely terminate near the bottom of the existing fill layer or extend
through the existing fill and penetrate the organic silt and peat deposits. Given the soft, compressible
nature of the organic silt and peat, we recommend over‐excavating light pole foundations through the
organic silt and peat to bear on the underlying alluvial sand deposits. Pole or post foundations supported
on undisturbed native alluvial sands may be designed for a maximum allowable, net end bearing capacity
of 2,000 psf. Pole or post foundations supported on GeoPiers or stone columns may be designed for a
maximum allowable, net end bearing capacity of 3,000 psf. Lateral and vertical capacities may be
increased by 1/3 to resist short term transient loads such as wind and seismic loads.
Backfilled Permanent Retaining Walls
Retaining walls are not described in the RFP document. However, we understand that the project may
include short cast‐in‐place concrete retaining walls less than about 4 feet tall and that geotechnical soil
Zipper Geo Associates, LLC
Proposed Renton Retail Development
Project No. 1217.01
February 7, 2014
Page 27
properties for use in retaining wall design have been requested. The following table presences
recommend soil design values for retaining walls.
Soil Parameters for Design of Retaining Walls
Design Parameter Recommended Design Value
Active Earth Pressure Coefficient (Horizontal Backfill)1 0.33
Active Earth Pressure Coefficient (2:1 Sloped Backfill)1 0.54
Soil Unit Weight
Dry: 110 pcf
Moist: 120 pcf
Saturated: 135 pcf
Passive Earth Pressure Coefficient 2 3.0
Allowable Soil Base Friction Coefficient 0.40
Soil Internal Friction Angle 30 degrees
Allowable Soil Bearing Capacity 3 2,500 psf
1. Active earth pressure calculations do not include wall friction.
2. Assumed that all fill placed in front of the wall is compacted in accordance with the recommendations in
this report. We recommend that passive resistance in the upper 1.5 feet of embedment be neglected.
3. Assumes that foundations are supported as presented in the Shallow Foundations section of this report.
Design of permanent retaining walls should consider additional earth pressure resulting from the design
seismic event. Section 1803.5.12 of the 2012 IBC requires the inclusion of dynamic seismic lateral earth
pressures on foundation walls and retaining walls supporting more than 6 feet of backfill. A uniformly
distributed pressure of 12H and 24H in pounds per cubic foot (rectangular distribution) may be applied to
yielding retaining walls with level backfill and 2H: 1V sloped backfill, respectively, to account for seismic
pressures.
Additional lateral earth pressures resulting from surcharges such as traffic loads, other surface loading, or
hydrostatic pressures, should be added, as appropriate.
Adequate drainage measures must be installed to collect and direct subsurface water away from subgrade
walls. All backfilled walls should include a drainage aggregate zone extending two feet from the back of
wall for the full height of the wall. The drainage aggregate should consist of material meeting the
requirements of WSDOT 9‐03.12(2) Gravel Backfill for Walls. The zone of Gravel Backfill for Walls should
extend down to a 4‐inch diameter perforated footing drain system as outlined in the Drainage
Considerations section of this report.
On‐Grade Concrete Slabs
We understand that the retail building will include moisture sensitive on‐grade concrete floors requiring
a minimum subgrade modulus of 100 pci.
Zipper Geo Associates, LLC
Proposed Renton Retail Development
Project No. 1217.01
February 7, 2014
Page 28
Subgrade Preparation: Subgrades for on‐grade slabs should be prepared in accordance with the Site
Preparation and Structural Fill sections of this report.
Capillary Break: To provide a capillary break, uniform slab bearing surface, and a minimum subgrade
modulus of 150 pci, we recommend the on‐grade slabs be underlain by a 6‐inch thick layer of compacted,
well‐graded granular fill contain less than 5 percent fines, based on that soil fraction passing the U.S. No.
4 sieve. Alternatively, a clean angular gravel such as No. 7 aggregate per WSDOT: 9‐03.1(4)C could be
used for this purpose. Alternative capillary break materials should be submitted to the geotechnical
engineer for review and approval before use.
Vapor Retarder: The use of a vapor retarder should be considered beneath concrete slabs on grade that
will be covered with wood, tile, carpet or other moisture sensitive or impervious coverings, or when the
slab will support equipment sensitive to moisture or is otherwise considered moisture‐sensitive. When
conditions warrant the use of a vapor retarder, the slab designer and contractor should refer to ACI 302
and/or ACI 360 for procedures and cautions regarding the use and placement of a vapor retarder.
Drainage Considerations
Surface Drainage: Final site grades should be sloped to carry surface water away from buildings and other
drainage‐sensitive areas. Additionally, site grades should be designed such that concentrated runoff on
softscape surfaces is avoided. Any surface runoff directed towards softscaped slopes should be collected
at the top of the slope and routed to the bottom of the slope and discharged in a manner that prevents
erosion.
Building Perimeter Footing Drains and Retaining Wall Drains: We recommend that the new building and
retaining walls be provided with a footing drain system to reduce the risk of future moisture problems
and the buildup of hydrostatic pressures. The footing drains should consist of a minimum 4‐inch diameter,
Schedule 40, rigid, perforated PVC pipe placed at the base of the heel of the footing with the perforations
facing down. The pipe should be surrounded by a minimum of 6 inches of clean free‐draining granular
material conforming to WSDOT Standard Specification 9‐03.12(4), Gravel Backfill for Drains. A non‐woven
filter fabric such as Mirafi 140N, or equivalent, should envelope the free‐draining granular material. At
appropriate intervals such that water backup does not occur, the drainpipe should be connected to a
tightline system leading to a suitable discharge. Cleanouts should be provided for future maintenance.
The tightline system must be separate from the roof drain system.
Pavements
We understand that the project will include flexible asphalt concrete pavement and ridged Portland
cement concrete pavements. Pavement design criteria provided in the project RFP is presented below.
Flexible & ridged pavement design in accordance with AASHTO design methods
Zipper Geo Associates, LLC
Proposed Renton Retail Development
Project No. 1217.01
February 7, 2014
Page 29
20‐year pavement design period
Light duty traffic loading: 7,500 18‐kip ESAL’s
Heavy duty traffic loading: 75,000 18‐kip ESAL’s
Terminal serviceability Index: 2.0
85% reliability
Asphalt Pavements
Pavement Life and Maintenance: It should be realized that asphaltic pavements are not maintenance‐
free. The following pavement sections represent our minimum recommendations for an average level of
performance during a 20‐year design life; therefore, an average level of maintenance will likely be
required. A 20‐year pavement life typically assumes that an overlay will be placed after about 12 years.
Thicker asphalt, base, and subbase courses would offer better ling‐term performance, but would cost
more initially. Conversely, thinner courses would be more susceptible to “alligator” cracking and other
failure modes. As such, pavement design can be considered a compromise between a high initial cost and
low maintenance costs versus a low initial cost and higher maintenance costs.
Soil Design Values: The pavement subgrade soils are anticipated to consist of existing import fill consisting
of sandy gravel to gravelly sand with some silt or new import structural fill consisting of Gravel Borrow.
Our analysis is based on an assumed California Bearing Ration (CBR) value of 20 percent.
Recommended Pavement Sections: For light duty pavements (parking lot areas), we recommend 2 inches
of asphalt concrete over 5 inches of crushed rock base course. For heavy duty pavements (main access
roads, truck delivery routes, etc.), we recommend 3 inches of asphalt concrete over 7 inches of crushed
rock base course.
Materials and Construction: We recommend the following regarding asphalt pavement materials and
pavement construction.
Subgrade Preparation: Upper 12 inches of pavement subgrade should be prepared in accordance
with the recommendations presented in the Subgrade Preparation section of this report.
Asphalt Concrete: We recommend that the asphalt concrete conform to Section 9‐02.1(4) for PG
58‐22 or PG 64‐22 Performance Graded Asphalt Binder as presented in the 2012 WSDOT Standard
Specifications. We also recommend that the gradation of the asphalt aggregate conform to the
aggregate gradation control points for ½‐inch mixes as presented in Section 9‐03.8(6), HMA
Proportions of Materials.
Base Course: We recommend that the crushed aggregate base course conform to Section 9‐
03.9(3) of the WSDOT Standard Specifications.
Zipper Geo Associates, LLC
Proposed Renton Retail Development
Project No. 1217.01
February 7, 2014
Page 30
Compaction: All base material should be compacted to at least 95 percent of the maximum dry
density determined in accordance with ASTM: D 1557. We recommend that asphalt be
compacted to a minimum of 92 percent of the Rice (theoretical maximum) density or 96 percent
of Marshall (Maximum laboratory) density.
Concrete Pavements
Concrete Properties and Thickness: Concrete pavement design recommendations are based on an
assumed modulus of rupture of 600 psi and a minimum compressive strength of 4,000 psi for the concrete.
For light duty pavements, we recommend 5 inches of concrete over 3 inches of crushed aggregate base.
For heavy duty pavements, we recommend 6 inches of concrete over 3 inches of crushed aggregate base.
Concrete Pavement Joints and Reinforcing: It is our opinion that concrete pavements should be reinforced
and have relatively closely spaced control joints on the order of 10 to 15 feet. We recommend that
minimum reinforcement consist of 6x6‐W2.0xW2.0 welded wire fabric or equivalent. We further
recommend that loading dock pavements be reinforced with #4 bars at 15 inches each direction.
CLOSURE
The analysis and recommendations presented in this report are based, in part, on the explorations
completed for this study. The number, location, and depth of the explorations were completed within the
constraints of budget and site access so as to yield the information to formulate our recommendations.
Project plans were in the preliminary stage at the time this report was prepared. We therefore
recommend Zipper Geo Associates, LLC be provided an opportunity to review the final plans and
specifications when they become available in order to assess that the recommendations and design
considerations presented in this report have been properly interpreted and implemented into the project
design.
A large portion of the planned building area is covered by the existing theater and entry and was not
accessible for explorations for this study. We recommend that additional explorations be completed in
this area for final design of ground improvement for the new foundations.
The performance of earthwork, structural fill, foundations, and pavements depend greatly on proper site
preparation and construction procedures. We recommend that Zipper Geo Associates, LLC be retained to
provide geotechnical engineering services during the earthwork‐related construction phases of the
project. If variations in subsurface conditions are observed at that time, a qualified geotechnical engineer
could provide additional geotechnical recommendations to the contractor and design team in a timely
manner as the project construction progresses.
Zipper Geo Associates, LLC
Proposed Renton Retail Development
Project No. 1217.01
February 7, 2014
Page 31
This report has been prepared for the exclusive use of CenterPoint Integrated Solutions, LLC, and their
agents, for specific application to the project discussed and has been prepared in accordance with
generally accepted geotechnical engineering practices. No warranties, either express or implied, are
intended or made. Site safety, excavation support, and dewatering requirements are the responsibility of
others. In the event that changes in the nature, design, or location of the project as outlined in this report
are planned, the conclusions and recommendations contained in this report shall not be considered valid
unless Zipper Geo Associates, LLC reviews the changes and either verifies or modifies the conclusions of
this report in writing.
B-12B-10B-5TA-B-3TA-B-5B-3B-14B-15B-16B-17B-24B-23TA-B-2B-22B-1TA-B-1B-25B-19B-26B-20B-21B-7B-8B-6B-4TA-B-4B-18B-9B-11B-13B-2FIGUREJob No.Zipper Geo Associates, LLC19023 36th Ave. W.,Suite DLynnwood, WASHT. of11SITE AND EXPLORATION PLANEXISTING CONDITION1217.01DATE: January 20142PROPOSED RENTON RETAIL DEVELOPMENT3751 East Valley Road,Renton, WashingtonSCALE IN FEET010010050LEGENDZIPPER GEO ASSOCIATES BORINGNUMBER AND APPROXIMATE LOCATION.BORINGS COMPLETED FOR THISPROJECT IN DECEMBER 2013.TERRA ASSOCIATES BORING NUMBERAND APPROXIMATE LOCATION.BORINGS COMPLETED FOR ACT IIITHEATERS PROJECT IN JANUARY 1996.TA-B-1B-1REFERENCE: DRAFT TOPOGRAPHIC SURVEY FOR PACLAND, PREPARED BY PACE, DATED 12/12/13. VERTICAL DATUM NAVD 88.PRIMARY PROPOSED DEVELOPMENTFEATURES. SEE FIGURE 3.
B-23B-22B-25B-26B-24B-1B-19B-17B-11B-20B-12B-16B-13B-10B-9B-18B-15B-5B-14B-4B-3B-21B-6B-7B-8TA-B-2TA-B-3TA-B-1TA-B-5TA-B-4STORMWATER MANAGEMENT AREA (1.14 ACRES)B-2FIGUREJob No.Zipper Geo Associates, LLC19023 36th Ave. W.,Suite DLynnwood, WASHT. of11SITE AND EXPLORATION PLANPROPOSED DEVELOPMENT1217.01DATE: January 20143PROPOSED RENTON RETAIL DEVELOPMENT3751 East Valley Road,Renton, WashingtonSCALE IN FEET010010050LEGENDZIPPER GEO ASSOCIATES BORINGNUMBER AND APPROXIMATE LOCATION.BORINGS COMPLETED FOR THISPROJECT IN DECEMBER 2013.TERRA ASSOCIATES BORING NUMBERAND APPROXIMATE LOCATION.BORINGS COMPLETED FOR REGALCINEMA PROJECT IN JANUARY 1996.TA-B-1B-1REFERENCE: PRELIMINARY SITE PLAN SP-16 DATED NOVEMBER 21, 2013
APPENDIX A
ZGA SUBSURFACE EXPLORATION PROCEDURES & LOGS
APPENDIX A
ZGA SUBSURFACE EXPLORATION PROCEDURES AND LOGS
Field Exploration Description
Our field exploration for this project included 26 borings completed between the 4th and 10th of December
2013. The approximate exploration locations are shown on the Site and Exploration Plans, Figures 2 & 3.
Exploration locations were determined by measuring distances from existing site features with a fiberglass
tape measure relative to a draft topographic site survey prepared by Pace Engineers dated December 12,
2013. The approximate ground surface elevation at the exploration locations was determined by
interpolating from topographic information provided on the survey. As such, the exploration locations and
elevations should be considered accurate only to the degree implied by the means and methods used to
define them. The topographic survey vertical datum is NAVD 88.
Boring Procedures
The borings were advanced using a Mobile B‐59 truck‐mounted drill rig operated by an independent
drilling company working under subcontract to ZGA. Borings B‐9, B‐10, and B‐11 were advanced using
mud rotary drilling methods. The remainder of the borings were advanced using hollow stem auger drilling
methods. An engineering geologist from our firm continuously observed the borings, logged the
subsurface conditions encountered, and obtained representative soil samples. All samples were stored
in moisture‐tight containers and transported to our laboratory for further evaluation and testing. Samples
were obtained by means of the Standard Penetration Test and thin wall Shelby tube sampler at 2.5‐ to 5‐
foot intervals throughout the drilling operation.
The Standard Penetration Test (ASTM: D‐1586) procedure consists of driving a standard 2‐inch outside
diameter steel split spoon sampler 18 inches into the soil with a 140‐pound hammer free falling 30 inches.
The number of blows required to drive the sampler through each 6‐inch interval is recorded, and the total
number of blows struck during the final 12 inches is recorded as the Standard Penetration Resistance, or
“blow count” (N value). If a total of 50 blows is struck within any 6‐inch interval, the driving is stopped
and the blow count is recorded as 50 blows for the actual penetration distance. The resulting Standard
Penetration Resistance values indicate the relative density of granular soils and the relative consistency
of cohesive soils.
The Shelby tube sampler (ASTM: D‐1587) was used to collect relatively undisturbed soil samples for
laboratory testing and consists of a 2.5 foot long, 3‐inch outside diameter, thin wall steel tube. The tube
is hydraulically pushed into and extracted from the soil, consequently no blow counts are recorded.
The enclosed boring logs describe the vertical sequence of soils and materials encountered in each boring,
based primarily upon our field classifications. Where a soil contact was observed to be gradational, our
logs indicate the average contact depth. Where a soil type changed between sample intervals, we inferred
the contact depth. Our logs also graphically indicate the blow count, sample type, sample number, and
approximate depth of each soil sample obtained from the boring. If groundwater was encountered in a
borehole, the approximate groundwater depth, and date of observation, are depicted on the log.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
B-1
B-1
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
0 20 40 60
6"
8"
14"
18"
18"
14"
S-1
S-2
S-3
S-4
S-5
S-6 ATDATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
23.5 Feet
12/4/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1228
25
1
3
9
6
JPG
MC=72%
MC=163%
5-1/2 inches ASPHALT
Medium dense, moist to wet, gray, sandy GRAVEL to
gravelly SAND, some silt (Fill)
Medium dense, wet grading to saturated, gray-brown to gray, gravelly SAND, with silt (Fill)
Very soft, wet, brown, organic SILT
Soft, wet, brown, fine fibrous PEAT
Very soft, wet to saturated, brown, organic SILT
Loose, saturated, dark gray, silty fine SAND to fine SAND with silt
Boring completed at 20 feet on 12-4-2013
Perched groundwater encountered at about 7 feet at time of
exploration.
Groundwater encountered at about 11 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
B-2
B-2
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
0 20 40 60
12"
14"
4"
2"
14"
14"
15"
S-1
S-2
S-3
S-4
S-5
S-6
S-7 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
23 Feet
12/4/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1236
31
3
3
4
10
10
JPG
6 inches ASPHALT
Dense, moist grading to moist to wet, gray, gravelly SAND,
with silt (Fill)
Soft, wet, brown, organic SILT.
soft, saturated, gray, fine sandy SILT
Loose, saturated, dark gray, fine SAND, with silt grading to
fine to medium SAND, some silt
Boring completed at 20 feet on 12-4-2013
Groundwater encountered at about 12 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
B-3
B-3
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
0 20 40 60
14"
14"
14"
12"
14"
16"
S-1
S-2
S-3
S-4
S-5
S-6
S-7 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
23.5 Feet
12/4/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/120
27
26
5
3
9
12
GSA
JPG
MC=72%
6 inches ASPHALT
Medium dense, moist grading to wet, gray, sandy GRAVEL, some silt grading to gravelly SAND, with silt (Fill)
Medium stiff, wet, brown, organic SILT, trace fibrous organic
material.
Soft, wet to saturated, gray SILT, some fine sand, trace
fibrous organic material
Loose, saturated, dark gray, fine to medium SAND, with silt
Loose grading to medium dense, saturated, dark gray, fine to
medium sand, some silt
Boring completed at 20 feet on 12-4-2013Groundwater encountered at about 10 feet at time of
exploration. Sample S-1 consists of auger cuttings collected
from 0.5 to 2.5 feet.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
B-4
B-4
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
0 20 40 60
13"
13"
15"
12"
12"
16"
S-1
S-2
S-3
S-4
S-5
S-6 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22 Feet
12/4/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1221
4
8
4
6
16
JPG
MC=77%
5-1/2 inches ASPHALT
Medium dense, moist grading to wet, gray, gravelly SAND,
some silt (Fill)
Soft, wet, brown, organic SILT, trace fibrous organic material
Loose, wet to saturated, gray, silty fine SAND to sandy SILT
Soft, wet, brown, organic SILT
Loose grading to medium dense, saturated, dark gray, fine to
medium SAND some silt
Boring completed at 20 feet on 12-4-2013
Groundwater encountered at about 8.5 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
B-5
B-5
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
0 20 40 60
14"
0"
13"
15"
14"
16"
S-1
S-2
S-3
S-4
S-5
S-6
S-7 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22 Feet
12/4/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/120
23
7
4
7
5
9
GSA
JPG
4 inches ASPHALT
Medium dense grading to loose, moist grading to wet, gray-
brown, gravelly SAND, some silt (Fill)
Soft, wet, brown, organic SILT
3-inches soft, wet, brown, fine fibrous PEAT
Loose, wet, gray, silty fine SAND to fine sandy SILT
Loose, saturated, dark gray, fine to medium sand, some silt
2-inches soft saturated, gray, silty CLAY
Loose, saturated, dark gray, fine SAND, with silt
Boring completed at 20 feet on 12-4-2013Groundwater encountered at about 11.5 feet at time of
exploration. Sample S-1 consists of auger cuttings collected
from 0.5 to 2.5 feet.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
B-6
B-6
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
0 20 40 60
12"
3"
18"
18"
18"
14"
S-1
S-2
S-3
S-4
S-5
S-6 AD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22 Feet
12/4/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1216
1
5
2
8
12
JPG
6 inches ASPHALT
Medium dense, moist to wet, gray, gravelly SAND, some silt (Fill)
Very soft, wet, brown, organic silt (wood in sampler tip)
Loose, wet to saturated, gray, silty fine SAND, trace fine
organics
Very loose, saturated, gray SILT, some fine sand, trace fine
organics
Loose grading to medium dense, saturated, dark gray, fine to
medium SAND, trace to some silt
Boring completed at 20 feet on 12-4-2013
Groundwater measured at 8.9 feet 20 minutes after drilling.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
B-7
B-7
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
0 20 40 60
14"
3"
14"
12"
16"
18"
S-1
S-2
S-3
S-4
S-5
S-6 ATDATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22 Feet
12/4/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1229
5
2
8
15
11
JPG
4-1/2 inches ASPHALT
Medium dense, moist, gray-brown, sandy GRAVEL, some
silt (Fill)
Medium dense, moist to wet, gray, silty SAND, some gravel
(Fill)
Medium stiff, wet to saturated, PEAT and organic SILT
Very soft, wet to saturated, gray SILT, with fine sand, trace
fine organics
Loose, saturated, dark gray, fine to medium SAND, some silt
Grades to medium dense
Boring completed at 20 feet on 12-4-2013Perched groundwater encountered at about 5.5 feet at time of
exploration.
Groundwater encountered at about 8 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
B-8
B-8
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
0 20 40 60
14"
0"
13"
18"
18"
14"
S-1
S-2
S-3
S-4
S-5
S-6 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22.5 Feet
12/4/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1222
7
9
11
9
2
JPG
4 inches ASPHALT
Medium dense grading to loose, moist, gray-brown, SAND,
with gravel, some silt (Fill)
Medium stiff, wet, brown, PEAT and organic SILT
Loose, wet to saturated, dark gray, fine SAND, with silt
Loose to medium dense, saturated, dark gray, fine to medium
SAND, trace to some silt
Loose, saturated, gray, silty fine SAND
Loose, saturated, dark gray, fine to medium SAND, some silt
(10-inches of heave, blow count understated)
Boring completed at 20 feet on 12-4-2013
Groundwater encountered at about 9 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
B-9
B-9
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 3
BORING
LOG:TestingPlastic Limit
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
0 20 40 60
12"
10"
4"
12"
14"
18"
14"
S-1
S-2
S-3
S-4
S-5
S-6
S-7 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22.5 Feet
12/5/2013
Holocene
Rotary Wash
Mobile B-59
6"
Auto
11/2/1251
22
5
12
9
12
17
GSA
GSA
GSA
JPG
4 inches ASPHALT
Dense grading to loose, moist grading to saturated, gray-brown, gravelly SAND, with silt (Fill)
Medium stiff, wet to saturated, brown, organic silt with 1/2-inch
thick fibrous peat interbeds
Loose to medium dense, saturated, gray, silty fine SAND
Medium dense, saturated, dark gray SAND, with silt
Medium dense grading to dense, saturated, dark gray SAND,
trace silt
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:
B-9
Date Drilled:Depth (ft)SOIL DESCRIPTION
Sample Number SAMPLES RecoveryGround WaterPENETRATION RESISTANCE (blows/foot)Blow CountsTesting3751 East Valley Road
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.
Plastic Limit
Natural Water Content
Proposed Renton Retail
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Renton, WA
1217.01
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
BORING
LOG:B-9
Page 2 of 3
1/10/2013
0 20 40 60
25
30
35
40
45
50
See Figure 2, Site and Exploration Plan
22.5 Feet
12/5/2013
Holocene
Rotary Wash
Mobile B-59
6"
Auto
11/2/1216"
16"
10"
12"
14"
S-8
S-9
S-10
S-11
S-12
27
36
0
12
9 GSA
JPG
Medium dense grading to dense, saturated, dark gray SAND,
trace silt
Very soft, saturated, light gray,ELASTIC SILT
Loose to medium dense, saturated, gray SAND, with silt, trace
shell fragments
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:
B-9
Date Drilled:Depth (ft)SOIL DESCRIPTION
Sample Number SAMPLES RecoveryGround WaterPENETRATION RESISTANCE (blows/foot)Blow CountsTesting3751 East Valley Road
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.
Plastic Limit
Natural Water Content
Proposed Renton Retail
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Renton, WA
1217.01
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
BORING
LOG:B-9
Page 3 of 3
1/10/2013
0 20 40 60
13"
14"
0"
13"
S-13
S-14
S-15
S-16
50
55
60
65
70
75
See Figure 2, Site and Exploration Plan
22.5 Feet
12/5/2013
Holocene
Rotary Wash
Mobile B-59
6"
Auto
11/2/1216
41
62
8
JPG
Loose to medium dense, saturated, gray SAND, with silt, trace
shell fragments
Dense to very dense, saturated, gray SAND, with silt, trace
shell fragments
Loose, saturated, gray, silty SAND, trace shell fragments
Boring completed at 64 feet on 12-5-2013
Groundwater encountered at about 8 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
B-10
B-10
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 3
BORING
LOG:TestingPlastic Limit
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
0 20 40 60
12"
12"
8"
12"
6"
15"
S-1
S-2
S-3
S-4
S-5
S-6 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22.5 Feet
12/5/2013
Holocene
Rotary Wash
Mobile B-59
6"
Auto
11/2/1241
34
12
7
9
5
GSA
GSA
GSA
JPG
4 inches ASPHALT
Dense grading to loose, moist grading to saturated, gray-
brown, gravelly SAND, with silt (Fill)
Loose, saturated, gray, silty SAND, trace fine organics
Soft,saturated, brown, organic SILT
Loose, saturated, dark gray, silty SAND
Soft, saturated, light gray SILT, some wood debris, trace fine
organics
Loose, saturated, dark gray, fine to medium SAND, some silt
Medium dense to dense, saturated, dark gray SAND, trace to
some silt
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Renton, WA
1217.01
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
BORING
LOG:B-10
Page 2 of 3
1/10/2013
3751 East Valley Road
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.
Plastic Limit
Natural Water Content
Proposed Renton Retail
Boring Location:
B-10
Date Drilled:Depth (ft)SOIL DESCRIPTION
Sample Number SAMPLES RecoveryGround WaterPENETRATION RESISTANCE (blows/foot)Blow CountsTesting0 20 40 60
25
30
35
40
45
50
See Figure 2, Site and Exploration Plan
22.5 Feet
12/5/2013
Holocene
Rotary Wash
Mobile B-59
6"
Auto
11/2/1214"S-7
14"
18"
14"
13"
15"
S-8
S-9
S-10
S-11
S-12
31
26
0
4
10
16
GSA
JPG
Medium dense to dense, saturated, dark gray SAND, trace to
some silt
Very soft, saturated, light gray,ELASTIC SILT, trace fine
organics
Loose, saturated, gray SAND, with silt, trace shell fragments
Medium dense, saturated, gray SAND, with silt, trace shell
fragments
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Renton, WA
1217.01
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
BORING
LOG:B-10
Page 3 of 3
1/10/2013
3751 East Valley Road
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.
Plastic Limit
Natural Water Content
Proposed Renton Retail
Boring Location:
B-10
Date Drilled:Depth (ft)SOIL DESCRIPTION
Sample Number SAMPLES RecoveryGround WaterPENETRATION RESISTANCE (blows/foot)Blow CountsTesting0 20 40 60
13"
16"
14"
S-13
S-14
S-15
50
55
60
65
70
75
See Figure 2, Site and Exploration Plan
22.5 Feet
12/5/2013
Holocene
Rotary Wash
Mobile B-59
6"
Auto
11/2/1215
31
26
JPG
Medium dense, saturated, gray SAND, with silt, trace shell
fragments
Medium dense to dense, saturated, gray SAND, with silt, trace
shell fragments
Boring completed at 62.5 feet on 12-5-2013
Groundwater encountered at about 8 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
B-11
B-11
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 4
BORING
LOG:TestingPlastic Limit
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
0 20 40 60
13"
12"
4"
8"
14"
11"
14"
S-1
S-2
S-3
S-4
S-5
S-6
S-7 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22.5 Feet
12/6/2013
Holocene
Rotary Wash
Mobile B-59
6"
Auto
11/2/1243
52
10
7
9
9
18
GSA
GSA
JPG
5.5 inches ASPHALT
Dense to very dense, wet, gray, SAND, with silt and gravel
(Fill)
Grades to loose, wet to saturated, gray-brown, silty SAND,
some gravel
Medium stiff, wet to saturated, brown, fibrous PEAT
Loose, saturated, dark gray, silty fine SAND
Medium dense, saturated, dark gray, fine to medium SAND,
with silt
Dense, saturated, dark gray, fine to medium SAND, trace to
some silt
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Renton, WA
1217.01
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
BORING
LOG:B-11
Page 2 of 4
1/10/2013
3751 East Valley Road
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.
Plastic Limit
Natural Water Content
Proposed Renton Retail
Boring Location:
B-11
Date Drilled:Depth (ft)SOIL DESCRIPTION
Sample Number SAMPLES RecoveryGround WaterPENETRATION RESISTANCE (blows/foot)Blow CountsTesting0 20 40 60
25
30
35
40
45
50
See Figure 2, Site and Exploration Plan
22.5 Feet
12/6/2013
Holocene
Rotary Wash
Mobile B-59
6"
Auto
11/2/1212"
10"
12"
16"
8"
S-8
S-9
S-10
S-11
S-12
34
36
0
17
13
Att.
GSA
JPG
Dense, saturated, dark gray, fine to medium SAND, trace to
some silt
Very soft, saturated, light gray, ELASTIC SILT
Medium dense, saturated, gray, fine to medium SAND, with
silt, trace shell fragments
Loose, saturated, gray, silty fine SAND, trace shell fragments
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Renton, WA
1217.01
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
BORING
LOG:B-11
Page 3 of 4
1/10/2013
3751 East Valley Road
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.
Plastic Limit
Natural Water Content
Proposed Renton Retail
Boring Location:
B-11
Date Drilled:Depth (ft)SOIL DESCRIPTION
Sample Number SAMPLES RecoveryGround WaterPENETRATION RESISTANCE (blows/foot)Blow CountsTesting0 20 40 60
12"
13"
12"
10"
4"
S-13
S-14
S-15
S-16
S-17
50
55
60
65
70
75
See Figure 2, Site and Exploration Plan
22.5 Feet
12/6/2013
Holocene
Rotary Wash
Mobile B-59
6"
Auto
11/2/129
40
25
16
27
GSA
JPG
Loose, saturated, gray, silty fine SAND, trace shell fragments
Dense, saturated, gray, fine SAND, with silt, trace shell
fragments
Medium dense, saturated, gray, silty fine SAND, trace shell
fragments
Medium dense, saturated, gray, fine to medium SAND, with
silt, trace shell fragments
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:
B-11
Date Drilled:Depth (ft)SOIL DESCRIPTION
Sample Number SAMPLES RecoveryGround WaterPENETRATION RESISTANCE (blows/foot)Blow CountsTesting3751 East Valley Road
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.
Plastic Limit
Natural Water Content
Proposed Renton Retail
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Renton, WA
1217.01
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
BORING
LOG:B-11
Page 4 of 4
1/10/2013
0 20 40 60
75
80
85
90
95
See Figure 2, Site and Exploration Plan
22.5 Feet
12/6/2013
Holocene
Rotary Wash
Mobile B-59
6"
Auto
11/2/1212''
12"
S-18
S-19
S-20
12
7
11
100
JPG
Medium dense, saturated, gray, fine to medium SAND, with
silt, trace shell fragments and organics
Loose, saturated, gray, fine SAND, with silt, trace shell
fragments
Medium dense, saturated, gray, silty fine SAND to sandy
SILT, trace shell fragments
Boring completed at 86.5 feet on 12-6-2013Groundwater encountered at about 9 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
B-12
B-12
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
0 20 40 60
13"
15''
12''
18''
11"
11''
S-1
S-2
S-3
S-4
S-5
S-6
S-7 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22.5 Feet
12/6/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1238
5
4
0
10
7
11
JPG
4 inches ASPHALTMedium dense to dense, moist, gray-brown, gravelly SAND,
with silt (Fill)
Grades to loose, wet to saturated, gray, SAND, with silt and
gravel
Soft to medium stiff, wet to saturated, brown, fine PEAT
Boring completed at 21.5 feet on 12-6-2013
Groundwater encountered at about 6 feet at time of
exploration.
Loose, saturated, dark dray, silty fine SAND
Loose, saturated, dark gray, fine SAND, with silt
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
B-13
B-13
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
0 20 40 60
13''
12''
12''
14''
12''
S-1
S-2
S-3
S-4
S-5
S-6 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22.5 Feet
12/6/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1244
7
0
7
9
26
JPG
4 inches ASPHALT
6-inches dense, moist, gray-brown, gravelly SAND with silt
(Fill)
Dense, wet, gray, silty SAND with gravel to silty gravelly
SAND
Grades to loose, wet, gray, silty SAND, some gravel
Soft, wet, brown, organic SILT, with peat
Very stiff, saturated, light gray, SILT, some fine sand, trace
clay and fine organics
Loose, saturated, dark gray, fine to medium SAND, some silt
0.5 to 1.5 inch thick dark gray silty fine sand interbed observed
at 15.5 feet
Boring completed at 21.5 feet on 12-6-13
Groundwater encountered at about 8 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
B-14
B-14
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
0 20 40 60
13''
14''
16''
18''
12''
18''
S-1
S-2
S-3
S-4
S-5
S-6 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22 Feet
12/9/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1255
5
7
8
17
51
JPG
4.5 inches ASPHALT
Dense, moist, gray-brown, gravelly SAND to sandy GRAVEL, with silt (Fill)
Very dense, moist to wet, gray, SAND, with gravel and silt
(Fill)
Grades to loose, saturated, gray, SAND, with silt, some gravel
Medium stiff, wet to saturated, brown, organic SILT
Medium stiff, saturated, brown, fine fibrous PEAT
Medium stiff, saturated, gray, SILT, some fine sand, trace clay
and fine organics
Loose, saturated, dark gray, fine SAND, with silt
Medium dense, saturated, dark gray, fine to medium SAND,
some silt
Grades to trace to some silt (S-6 blow count overstated -
heave in sampler)
Boring completed at 20 feet on 12-9-13
Groundwater encountered at about 5.5 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
B-15
B-15
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
0 20 40 60
13''
15''
6''
14''
14''
14''
S-1
S-2
S-3
S-4
S-5
S-6 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
23.5 Feet
12/9/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1245
56
3
4
14
19
JPG
4.5 inches ASPHALT
3-inches medium dense to dense, gray-brown, gravelly
SAND, some silt (Fill)
Dense to very dense, moist to wet, gray, sandy GRAVEL to
gravelly SAND, some silt (Fill)
Soft, saturated, brown, organic SILT
Soft, saturated, brown, fine fibrous PEAT
Soft, wet to saturated, gray-brown, silty CLAY, trace organics
Medium dense, saturated, dark gray, silty fine SAND
Medium dense, saturated, dark gray, fine to medium SAND,
some silt
Boring completed at 20 feet on 12-9-13
Groundwater encountered at about 7 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
B-16
B-16
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
0 20 40 60
8''
12''
18''
15''
18''
18''
S-1
S-2
S-3
S-4
S-5
S-6 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
23 Feet
12/9/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1243
23
7
6
17
5
JPG
4.5 inches ASPHALT
6-inches medium dense to dense, gray-brown, sandy
GRAVEL to gravelly SAND, some silt (Fill)
Dense, wet, gray, sandy GRAVEL, some silt (Fill)
Grades to medium dense, saturated, gray-brown, SAND, with gravel and silt
Medium stiff, wet to saturated, brown, organic SILT, with 2
inch fibrous peat interbeds
Soft, saturated, gray-brown, SILT, with clay, 0.125 to 0.25 inch
thick peat and organic silt interbeds
Loose to medium dense, saturated, gray, silty fine SAND to
fine sandy SILT
Loose to medium dense, saturated, dark gray, fine to medium,
SAND, some silt
Soft, saturated, gray-brown, organic silt
Loose, saturated, dark gray, fine to medium SAND, some silt
Boring completed at 20 feet on 12-9-13Groundwater encountered at about 7 feet at time of
exploration.
MC=63%
MC=77%
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
B-17
B-17
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
0 20 40 60
14''
12''
14''
16''
18''
18''
S-1
S-2
S-3
S-4
S-5
S-6 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
23 Feet
12/9/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1236
16
9
4
11
8
JPG
2.5 inches ASPHALT over 3 inches ATB
3 inches sandy GRAVEL, some silt (Fill)
Dense, moist to wet, gray, gravelly SAND, with silt (Fill)
Grades to medium dense, saturated SAND, with silt and
gravel
Medium stiff, wet, brown, organic SILT
Medium stiff, wet, brown, fine fibrous PEAT
Soft, wet to saturated, brown, organic SILT, trace fine fibrous
organic material
Medium dense, saturated, gray, silty fine SAND to fine sandy
SILT
Loose, saturated, dark gray, silty fine SAND to fine sandy
SILT, with 0.5 to 1.5 inch interbeds of fine to medium SAND,
some silt
Boring completed at 20 feet on 12-9-13
Groundwater encountered at about 6 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
B-18
B-18
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
0 20 40 60
14''
12''
16''
16''
14''
S-1
S-2
S-3
S-4
S-5
S-6 ADATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22 Feet
12/9/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1244
9
0
7
5
14
JPG
4.5 inches ASPHALT
Medium dese to dense, moist, gray-brown, sandy GRAVEL to
gravelly SAND, some silt (Fill)
Dense, wet, gray, SAND, some gravel and silt (Fill)
Grades to loose and saturated
Soft,wet, brown organic SILT, with PEAT interbeds
Medium stiff, saturated, gray, SILT, some fine sand
Loose, saturated, gray to dark gray, silty fine SAND to fine
sandy SILT
Medium dense, saturated, dark gray, fine to medium SAND,
trace to some silt
Boring completed at 20 feet on 12-9-13Perched groundwater encountered at about 5.5 feet at time of
exploration.
Groundwater measured at about 9.6 feet 30 minutes after
drilling.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
B-19
B-19
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
0 20 40 60
12''
13''
18''
6''
14''
0''
S-1
S-2
S-3
S-4
S-5
S-6 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22.5 Feet
12/9/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1266
13
7
13
13
11
JPG
4.5 inches ASPHALT
4 inches medium dense to dense, moist, brown, sandy
GRAVEL to gravelly SAND, some silt (Fill)
Dense, moist to wet, gray, SAND, with silt and gravel (Fill)
Grades to medium dense and saturated
Soft, wet, brown, organic SILT, trace fibrous organic material
Soft, wet, brown, fine fibrous PEAT
Soft, wet, brown, organic SILT
Loose to medium dense, saturated, dark gray, fine SAND, with
silt
Medium dense, saturated, dark gray, silty fine SAND, to fine
sandy SILT, with occasional 0.25 to 0.5 inch brown silt seams
Medium dense, saturated, dark gray, fine to medium SAND,
trace to some silt
Boring completed at 20 feet on 12-9-13
Perched groundwater encountered at about 5 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
B-20
B-20
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
0 20 40 60
12''
10''
18''
18''
13''
14''
S-1
S-2
S-3
S-4
S-5
S-6
S-7 ATDATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22.5 Feet
12/9/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/120
49
12
6
7
12
10
JPG
4 inches ASPHALT
4 inches medium dense, moist, brown, gravelly SAND, with
silt.Bulk sample S-1 taken from 4 to 8 inches
Dense, moist to wet, gray, SAND, with gravel, some silt (Fill)
Grades to medium dense and saturated
Soft, wet, gray-brown, organic SILT, trace fibrous organic
material
Medium stiff, wet, brown, fine fibrous peat
Soft, wet, gray-brown, organic SILT, trace fibrous organic
material
Loose, saturated, gray to dark gray, interbedded silty fine
SAND and fine sandy SILT
Medium dense, saturated, dark gray, fine to medium SAND,
some silt
Grades to loose
Boring completed at 20 feet on 12-9-13
Perched groundwater encountered at about 5 feet at time of
exploration.
Groundwater encountered at about 10.5 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
B-21
B-21
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
0 20 40 60
16''
12''
18''
18''
18''
18''
S-1
S-2
S-3
S-4
S-5
S-6 ATDATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
22 Feet
12/9/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1234
8
3
6
10
16
JPG
4 inches ASPHALT4 inches medium dense to dense, moist, brown, gravelly
SAND to sandy GRAVEL, some silt (Fill)
Dense, moist to wet, gray, SAND, with gravel, some (Fill)
Grades to loose and saturated
Soft, wet, brown, organic SILT, trace fine fibrous organic
material
Soft, wet, brown, fibrous PEAT
Very loose, wet to saturated, gray, silty SAND to sandy SILT, trace fine organics
Loose, saturated, gray, silty fine SAND grading to fine to
medium SAND, with silt
3 inches medium stiff, saturated, brown, organic SILT, with
peat
Medium dense, saturated, dark gray, fine to medium SAND,
trace to some silt
Boring completed at 20 feet on 12-9-13
Perched groundwater encountered at about 5 feet at time of
exploration.
MC=74%
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/1/2013
B-22
B-22
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
0 20 40 60
14''
12''
14''
16''
10''
14''
S-1
S-2
S-3
S-4
S-5
S-6 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
24 Feet
12/10/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1223
37
24
6
13
15
JPG
6 inches ASPHALT
2 inches medium dense, brown, gravelly SAND to sandy GRAVEL, some silt (Fill)
Medium dense, wet, gray to gray-brown, SAND with gravel, some silt (Fill)
Grades to saturated
Soft, wet, brown, organic SILT
Soft, wet, brown, fibrous PEAT
Medium dense, saturated, dark gray, fine SAND, with silt
Medium dense, saturated, dark gray, finely interbedded silty
fine SAND and fine sandy SILT
Boring completed at 20 feet on 12-10-13
Groundwater encountered at about 8 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
B-23
B-23
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
0 20 40 60
12''
12''
14''
16''
18''
0''
S-2
S-3
S-4
S-5
S-6
S-7
S-1
AD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
24 Feet
12/10/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1223
37
24
6
13
15
0
JPG
6 inches ASPHALT
Medium dense, moist, brown, SAND, with gravel, some silt
(Fill). Bulk sample collected from 6 to 12 inches.
Medium dense to dense, moist to wet, gray-brown, gravelly SAND, some silt (Fill)
grades to wet to saturated
Soft, wet, gray to gray-brown, organic silt
Soft, wet, brown, fibrous PEAT
Loose, saturated, dark gray, finely interbedded silty fine SAND
and fine sandy SILT
Medium dense, saturated, dark gray, fine to medium SAND,
some silt
Medium dense, saturated, dark gray, fine SAND, with silt
Boring completed at 20 feet on 12-10-13
Groundwater encountered at about 5 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
B-24
B-24
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
0 20 40 60
12''
12''
16''
18''
18''
16''
14''
S-1
S-2
S-3
S-4
S-5
S-6
S-7 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
23 Feet
12/10/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1225
44
4
4
4
12
7
JPG
5.5 inches ASPHALT
6 inches medium dense, moist, brown, sandy GRAVEL, some silt
Medium dense to dense, moist to wet, gray, SAND, with
gravel, some silt
Grades to loose to saturated
Soft, wet, brown, organic SILT
Soft, saturated, fine fibrous PEAT
Soft, saturated, organic SILT
Soft, saturated, gray to dark gray, fine sandy SILT
Medium dense, saturated, dark gray, silty fine SAND, with
sandy silt interbeds
Loose, saturated, dark gray, interbedded silty fine SAND and
SILT, with fine sand
Boring completed at 20 feet on 12-10-13
Groundwater encountered at about 7.5 feet at time of
exploration.
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
B-25
B-25
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
0 20 40 60
12''
4''
12''
0''
18''
16''
S-1
S-2
S-3
S-4
S-5
S-6 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
23 Feet
12/10/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/1246
13
1
4
5
11
JPG
4 inches ASPHALT
8 inches dense, moist, brown, sandy GRAVEL, some silt (Fill)
Dense, wet, gray, gravelly SAND, with silt (Fill)
Grades to and saturated
Soft, wet to saturated, brown, organic silt, trace fibrous organic
material
Soft, wet to saturated, brown, organic silt
Soft, saturated, gray, fine sandy SILT
Loose, saturated, gray to dark gray, interbedded silty fine
SAND and SILT with fine sand
Medium dense, saturated, dark gray, fine to medium SAND,
some silt
Boring completed at 20 feet on 12-10-13
Groundwater encountered at about 6.5 feet at time of
exploration.
Soft, wet to saturated, gray-brown, interbedded organic SILT
and fine fibrous peat
Drilling Company:Bore Hole Dia.:
Top Elevation:Drilling Method:Hammer Type:
Drill Rig:Logged by:
Standard Penetration Test
Hammer Weight and Drop:
SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm)
2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content
3-inch I.D. Shelby tube sample Bentonite Liquid Limit
Grout/Concrete
Screened Casing
TESTING KEY Blank Casing
GSA = Grain Size Analysis
200W = 200 Wash Analysis Date:Project No.:
Consol. = Consolidation Test
Att. = Atterberg Limits
Boring Location:Sample Number SAMPLES RecoveryDepth (ft)SOIL DESCRIPTION
Date Drilled:
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot)
B-26
B-26
1217.01Blow CountsProposed Renton Retail
3751 East Valley Road
Zipper Geo Associates
19023 36th Ave. W, Suite D
Lynnwood, WA
Renton, WA
Page 1 of 1
BORING
LOG:TestingPlastic Limit
Groundwater level at
time of drilling (ATD) or
on date of
measurement.
Natural Water Content
1/10/2013
0 20 40 60
Bul
k
12''
12''
6''
18''
18''
18''
S-1
S-2
S-3
S-4
S-5
S-6
S-7 ATD0
5
10
15
20
25
See Figure 2, Site and Exploration Plan
23.5 Feet
12/10/2013
Holocene
Hollow Stem Auger
Mobile B-59
6"
Auto
11/2/120
69
48
5
5
17
28
GSA
JPG
4 inches ASPHALT
4 inches medium dense, brown, gravelly SAND, some silt
(Fill)
Dense to very dense, wet, gray, gravelly SAND, some silt (Fill)S-1 bulk sample taken from 1 to 2.5 feet.
Grades to loose, saturated, gray, SAND, with gravel and silt
Soft, wet to saturated, brown, organic SILT
Soft, wet to saturated,brown, fine fibrous PEAT
Medium stiff, saturated, gray-brown, organic SILT, some
fibrous organic material
Medium dense, saturated, dark gray, fine to medium SAND,
some silt
S-7 blow count overstated. Heave in sampler.
Boring completed at 20 feet on 12-10-13
Groundwater encountered at about 7 feet at time of
exploration
APPENDIX B
ZGA LABORATORY TESTING PROCEDURES & RESULTS
APPENDIX B
ZGA LABORATORY TESTING PROCEDURES AND RESULTS
A series of laboratory tests were performed by ZGA and a subcontract testing laboratory during the course
of this study to evaluate the index and geotechnical engineering properties of the subsurface soils.
Descriptions of the types of tests performed are given below.
Visual Classification
Samples recovered from the exploration locations were visually classified in the field during the
exploration program. Representative portions of the samples were carefully packaged in moisture tight
containers and transported to our laboratory where the field classifications were verified or modified as
required. Visual classification was generally done in accordance with ASTM D2488. Visual soil
classification includes evaluation of color, relative moisture content, soil type based upon grain size, and
accessory soil types included in the sample. Soil classifications are presented on the exploration logs in
Appendix A.
Moisture Content Determinations
Moisture content determinations were performed on representative samples obtained from the
explorations in order to aid in identification and correlation of soil types. The determinations were made
in general accordance with the test procedures described in ASTM D 2216. Moisture contents are
presented on the exploration logs in Appendix A.
Grain Size Analysis
A grain size analysis indicates the range in diameter of soil particles included in a particular sample. Grain
size analyses were performed on representative samples in general accordance with ASTM: D‐2487. The
results of the grain size determinations for the samples were used in classification of the soils, and are
presented in this appendix.
Laboratory Maximum Density Test
The laboratory maximum density represents the highest degree of density which can be obtained from a
particular soil type by imparting a predetermined compaction effort. The test determines the “optimum”
moisture content of the soil at the laboratory maximum density. The laboratory maximum density test
was performed on a bulk sample of material in general accordance with ASTM: D‐1557. The test result is
shown in this appendix and presented as a curve where the soil dry density is compared to the moisture
content.
Atterberg Limits
Atterberg limits are used primarily for classification and indexing of cohesive soils. The liquid and plastic
limits are two of the five Atterberg limits and are defined as the moisture content of a cohesive soil at
arbitrarily established limits for liquid and plastic behavior, respectively. Liquid and plastic limits were
established for selected samples in general accordance with ASTM: D‐423 and ASTM: D‐424, respectively.
The results of the Atterberg limits are presented on a plasticity chart in this appendix where the plasticity
index (liquid limit minus plastic limit) is related to the liquid limit. The plastic limits and liquid limits are
also presented adjacent to appropriate samples on the exploration logs in Appendix A.
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: GP-GM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-3 0.5 to 2.5 4.2
Poorly graded
GRAVEL with silt
and sand
S-1 9.1
1217.01
12/11/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SP-SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-5 0.5 to 2 4.9
Poorly graded
SAND with silt and
gravel
S-1 6.5
1217.01
12/11/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-9 7.5 13.0 Silty SAND with
gravelS-3 15.1
1217.01
12/9/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-9 12.5 33.0 Silty SANDS-5 40.5
1217.01
12/9/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-9 20.0 28.6 Silty SANDS-7 20.9
1217.01
12/9/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-9 45.0 28.8 Silty SANDS-12 17.5
1217.01
12/9/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-10 7.5 16.5 Silty SANDS-3 19.8
1217.01
12/9/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-10 10.0 3.4 Silty SANDS-4 37.8
1217.01
12/9/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-10 15.0 31.0 Silty SANDS-5 44.9
1217.01
12/9/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-10 40.0 26.8 Silty SANDS-11 15.9
1217.01
12/11/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-11 12.5 33.0 Silty SANDS-5 36.0
1217.01
12/11/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-11 20.0 28.2 Silty SANDS-7 15.5
1217.01
12/11/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-11 45.0 30.0 Silty SANDS-12 22.8
1217.01
12/11/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-11 65.0 29.0 Silty SANDS-16 29.2
1217.01
12/11/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
0
10
20
30
40
50
60
70
80
90
100
0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS
GRAIN SIZE ANALYSIS
Comments: Unified Soil Classification System (UCSC) designation: SP-SM
36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200
Coarse Medium Fine Silt ClayFineCoarse
COBBLESBOULDERS GRAVEL SAND FINE GRAINED
SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER
Project No.:PROJECT NAME:
Proposed Renton RetailDATE OF TESTING:
Exploration Sample Depth (feet)Moisture (%)Fines (%)Description
B-26 1 to 2.5 8.6
Poorly graded
SAND with silt and
gravel
S-1 7.6
1217.01
12/11/2013
ASTM D 422Test Results Summary
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
90
95
100
105
110
115
120
125
130
135
140
145
150
0 5 10 15 20 25 30 35 40 45Dry Unit Weight (pcf)Moisture Content (%)
LABORATORY
COMPACTION
CURVE Renton, WA
Compaction Size
Test Standard Mold
Renton Retail
Job No.
Job Name
Date Tested
Sample No.
Location
Test Results
Zipper Geo Associates, LLC 19023 36th Avenue West, Suite D Lynnwood, Washington 98036 (425) 582-9928
Test No.Field Moist.2 3 4
Dry Density (lbs/cu.ft.)145.0 136.6 144.7
Moisture Content (%)6.4 4.3 5.2
ASTM D1557 6-inch
2.80
2.70
2.60
2.50
2.40
Zero Air Voids Curves For
Various Specific Gravities
1217.01
Depth / Elevation12/26/2013
B-5, S-1
0.5 to 2 feet
145.2
FILL: USCS Designation SP-SM
146.6
5.76.0
Maximum Dry Density / Oversize Corrected (pcf)
Opt. Moisture Content / Oversize Corrected (%)
Sample Description:
Comments:
Oversize Fraction (%) / Sieve Used 3/48
Received Liquid Plastic Plasticity
Symbol Boring Sample M.C. (%)Limit Limit Index
B-11 S-10 55 52 30 22
B-17 S-4 78 71 42 28
Remarks:
PLASTICITY CHART
ASTM D 4318
Elastic Silt
Comments
USCS
MH
Description
OH Organic Silt
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100Plasticity Index %Liquid Limit %
ML
U-line
A-line
Inorganic clays of
high plasticity
CH Micaceous or diatomaceous fine
sandy and silty soils; elastic silts;
organic silts, clays, and silty clays
OH
or
MH
Low plastic inorganic
clays; sandy and silty
clays Medium
plastic
inorganic
clays
7
4
Inorganic and organic silts and silty clays of
low plasticity; rock flour; silty or clayey fine
sands
ML
or OLCL
CL-ML
Silty clays;
clayey silts
and sands
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants
PROJECT NO:PROJECT NAME:
Renton RetailDATE OF TESTING:
1217.01
1/15/2014
APPENDIX C
LIQUEFYPRO SUMMARY OUTPUT FILES
APPENDIX C
LIQUEFYPRO SUMMARY OUTPUT FILES
The computer program LiquefyPro Version 5.8 was used to evaluate potential seismic induced liquefaction
and settlement for this project. Select summary output files for borings B‐9 through B‐11 for ground
shaking associated with the Maximum Considered Earthquake Geometric Mean (MCEG) Peak Ground
Acceleration in accordance with the 2012 International Building Code (IBC) are enclosed in this appendix.
The enclosed summary output files are provided for informational purposes and do not constitute our
entire liquefaction evaluation. Please refer to the liquefaction section of this report for our conclusions
relative to liquefaction for this project
LiquefyPro CivilTech Software USA www.civiltech.comZipper Geo Associates, LLC.
LIQUEFACTION ANALYSIS
Renton Retail Development
B-9: 2475 yr Return Period Plate C1
Hole No.=B-9 Water Depth=5 ft Surface Elev.=22.5 Magnitude=6.84
Acceleration=0.52g
(ft)0
10
20
30
40
50
60
70
51 130
22 130
5 100 15
12 70 NoLq
9 105 40
12 105 40
17 115 21
27 120
36 125
0 90 NoLq
12 100 18
9 100 18
16 110 18
41 130
62 130
8 100
Gravelly SAND, w ith silt
Organic SILT & PEAT
Silty fine SAND
SAND, with silt
SAND, trace silt
CLAY, some silt
SAND, with silt, trace shell fragments
SAND, with silt, trace shell fragments
Silty SAND, trace shell fragments
Raw Unit FinesSPT Weight %Shear Stress Ratio
CRR CSR fs1
Shaded Zone has Liquefaction Potential
01Soil Description Factor of Safety051Settlement
Saturated
Unsaturat.
S = 5.87 in.
0 (in.) 10
fs1=1
LiquefyPro CivilTech Software USA www.civiltech.comZipper Geo Associates, LLC.
LIQUEFACTION ANALYSIS
Renton Retail Development
B-10: 2475 yr Return Period Plate C2
Hole No.=B-10 Water Depth=5 ft Surface Elev.=22.5 Magnitude=6.84
Acceleration=0.52g
(ft)0
10
20
30
40
50
60
70
41 130
34 130
12 105 20
7 100 38
9 105 45
5 100 45
31 120
26 120
0 90 NoLq
4 90 NoLq
10 100 16
16 110 15
15 110 15
31 130
26 130
Gravelly SAND, w ith silt
Silty SAND, trace fine organics
Organic SILT
Silty SAND
SILT, trace fine organicsSAND, some silt
SAND, trace to some silt
CLAY, with silt
SAND, with silt
SAND, with silt, trace shell fragments
SAND, with silt, trace shell fragments
Raw Unit FinesSPT Weight %Shear Stress Ratio
CRR CSR fs1
Shaded Zone has Liquefaction Potential
01Soil Description Factor of Safety051Settlement
Saturated
Unsaturat.
S = 7.14 in.
0 (in.) 10
fs1=1
LiquefyPro CivilTech Software USA www.civiltech.comZipper Geo Associates, LLC.
LIQUEFACTION ANALYSIS
Renton Retail Development
B-11: 2475 yr Return Period Plate C3
Hole No.=B-11 Water Depth=5 ft Surface Elev.=22.5 Magnitude=6.84
Acceleration=0.52g
(ft)0
15
30
45
60
75
90
105
43 130
52 130
10 105
7 70 NoLq
9 105 36
9 105 36
18 110 15
34 120
36 120
0 90 NoLq
17 110 23
13 110 23
9 105 30
40 130
25 125
16 110 29
27 125 29
12 110 29
7 100
11 110
SAND, with silt and gravel
Fibrous PEAT
Silty SAND
SAND, with silt
SAND, trace to some silt
CLAY, some silt
SAND, with silt, trace shell fragments
Silty SAND, trace shell fragments
SAND, with silt, trace shell fragments
Silty SAND, trace shell fragments
SAND, with silt, trace shell fragments
SAND, with silt, trace shell fragments
Silty SAND, trace shell fragments
Raw Unit FinesSPT Weight %Shear Stress Ratio
CRR CSR fs1
Shaded Zone has Liquefaction Potential
01Soil Description Factor of Safety051Settlement
Saturated
Unsaturat.
S = 10.42 in.
0 (in.) 50
fs1=1
APPENDIX D
SUBSURFACE EXPLORATIONS & LABORATORY TESTING RESULTS BY OTHERS
APPENDIX D
SUBSURFACE EXPLORATIONS & LABORATORY TESTING RESULTS BY OTHERS
As part our geotechnical evaluation for this project, ZGA completed a review of the following geotechnical
report prepared for the site.
Geotechnical Report, Act III Theaters, SW 41st Street and East Valley Highway, Renton, Washington,
prepared by Terra Associates, Inc., dated January 30, 1996.
Copies of the subsurface explorations (borings B‐1 through B‐5) and laboratory test results from the
referenced report are enclosed in this appendix. The approximate exploration locations presented in the
referenced report are shown on Figures 2 and 3 and should be considered approximate.