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GEOTECHNICAL ENGINEERING STUDY
MERRILL GARDENS AT RENTON CENTRE
RENTON,WASHINGTON
Project No. G-1812 I
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Prepared for NOV 0 9 2004
Mr. Steve Friedman �U1l.�+��(aC��V����"��
Friedman Development, LLC
P.O. Box 1018
7426 SE 27'� Street, Suite 200
Mercer Island, WA 98040
June 14, 2004
GEO GROUP NORTHWEST, INC.
13240 NE 20th Street, Suite 12
Bellevue, Washington
Phone (425) 649-8757
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, Geotechnical Engineers,Geologists
r o u p N o r t h w e s t, I n c• 8 Environmental Scientists
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June 14, 2004 G-1812
Mr. Steve Friedman
Friedman Development, LLC
7426 SE 27"' Street, Suite 200
Mercer Island, WA 98040
Subject: Geotechnical Engineering Study
Merrill Gardens at Renton Centre
Renton, Washington
Dear Mr. Friedman:
Geo Group Northwest, Inc. conducted a geotechnical engineering study for the proposed Memll
Gardens at Renton Centre development at the McLendon Hardware site in Renton, Washington.
The proposed Merrill Gardens development will include a five story retirement center and two-
story parking garage. The subsurface soil and groundwater conditions at the site were
investigated by drilling three borings to depths of up to 34 feet. The site is underlain by
interbedded alluvial soils consisting of silts, sands, and gravels. About 8.5 feet of fill was
encountered at the north end of the site. Groundwater was encountered at a depth of 17.5 to 22
feet.
Based on the standard penetration test blow counts (N-values), soils in the upper 9.5 to 12,5 feet
are susceptible to settlement and are not suitable for supporting the building on shallow
conventional spread footings or non-structural slab-on-grade floors without improving the bearing
capacity of the site soils. Based on the site conditions encountered, the structure(s) may be
supported by augercast piles, helical anchors, short aggregate piers (rock column's or
GeopiersTM), or the unsuitable soils may by removed and replaced with structural fill. Supporting
the building on short aggregate piers or over-excavating and replacing the loose soils would allow
the building to be supported on conventional spread footings and slab-on-grade floors.
Temporary shoring may be required if open cuts are restricted by property lines or if the bearing
support of adjacent structures will be compromised.
Geo Group Northwest, Inc.
13240 NE 20th Street,Suite 12 • Belleuve,Washington 98005
Phone 425l649-8757 • FAX 425/649-8758
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Merrill Gardens at Renton Centre Page ii
Geotechnical Engineering Study
We appreciate this opportunity to provide geotechnical engineering services. Should you have
any questions regarding this report or need additional consultation during the design and
construction phases, please call us.
Sincerely, �c°t Y�t a s h��9
GEO GROUP NORTHWEST, INC. ��, ��
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Wade J. Lassey 1�Vade ,1, L.�ssey
Engineering Geologist
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William Chang, P.E. � Z ,
Principal � -- �
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EXPIRES: 2/19/
Geo Group Northwest, Inc.
TABLE OF CONTENTS
Project No. G-1812
1.0 INTRODUCTION Pa�e
l.l PROJECT DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 SCOPE OF SERVICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.0 SITE CONDITIONS
2.1 $URFACE CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.2 $UBSURFACE CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.3 GROiJNDWATER CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.0 SEISMICITY
3.1 LIQiJEFACTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.2 GROLJND MOTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.3 UBC CLASSIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.0 DISCUSSIONS AND RECOMMENDATIONS
4.1 GENERAI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.2 SITE PREPARATION 8L GEIJERAL EARTHWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
a.2.1 Temporary Erosion Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.2.2 Excavations and Slopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.2.3 Site Soils, Subgrade Stabilization, & Concrete Rubble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.2.4 Structura1Fi11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.3 TEMPORARY EXCAVATION SHORING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.4 Fotl�nlzotvs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.4.1 Augercast Piles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 �
4.4.2 HelicalAnchors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.4.3 Short Aggregate Piers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
�1.4.4 Conventional Spread Footing Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.� PERMANENT BASEMENT WALLS AND RETAIIIING WALLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.6 SLAB-ON-GRADE FLOORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 �
4.7 Dx,�1AGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1�
4.7.1 Surface Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.7.2 Footing Drains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.7.3 Basement Wall Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.8 PAVEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.0 LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.0 PLAN REVIEW & CONSTRUCTION MOMTORING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
ILLUSTRATIONS: Plate 1 - Vicinity Map
Plate 2 - Site Plan
Plate 3 - Footing Drain Detail
APPENDIX A: Boring Logs
GEOTECHNICAL ENGINEERING STUDY
PROPOSED RETIREMENT CENTER
MCLENDON HARDWARE SITE ,
RENTON,WASHINGTON
Project No. G-1812 I
1.0 INTRODUCTION
1.1 PROJECT DESCRIPTION 'I
The preliminary conceptual site development plan is to construct a five-story wood framed
building and two-story parking garage on the site. The parking garage will be attached and ''�
incorporated into the eastern portion of the structure. Overall, the proposed building will
generally be rectangular in shape and occupy the majority of the width and length of the property.
The property measures approximately 120 feet wide east/west and 550 feet long north/south. The
main floor of the building will be about the same elevation as the existing site gade and the
bottom floor of the parking structure will have a finished floor elevation about 6 feet below grade.
1.2 SCOPE OF SERVICES
�
The scope of work for this geotechnical study was conducted in general accordance with our
proposal dated May 20, 2004 and includes:
• Drilling three borings to characterize the subsurface conditions. Record of standard
penetration tests (SPT) and collection of soil samples. Analysis of sample moisture
content and preparation of boring logs.
• Evaluation of the subsurface conditions, engineering analysis, and geotechnical
recommendations and design criteria for the proposed five-story retirement center and
parking garage.
• Preparation of this written report with our activities, findings, conclusions, and
geotechnical recommendations.
' Geo Group Northwest, Inc.
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2.0 SITE CONDITIONS
2.1 SURFACE CONDITIONS
The project site is located at the southeast corner of South Tobin Street and Burnett Avenue
South, as indicated on the Vicinity Map, Plate 1, in the downtown area of Renton, Washington.
The site is currently occupied by the McClendon's Hardware store, McClendon's material storage
yard, and paved parking lots.
The project site is relatively flat and generally rectangular in shape, measuring appro3cimately 550
feet north/south by 120 feet east/west (1.5 acres). The site is bordered to the east by a paved
alley, single family and multifamily residences, and the McLendon's Hardware Store at the
southeast corner. McLendon's parking lot is located south of the site. To the north and west are
South Tobin Street and Burnett Avenue South, respectively.
2.2 SUBSURFACE COIYDITIONS
According to the "Preliminarv Geolo�ie c Map of the Renton Quadrangle, King CountX,
Washington," by D. R. Mullineaux, dated 1965 and published by the Department of the Interior,
United States Geological Survey, the project site is mapped as urban or industrial land modified
by widespread or discontuiuous artificial fill (afm). The site is located in the Cedar River Valley
approxirriately 200 feet southwest of the Cedar River. The soils along the Cedar River are
mapped as alluvium, consisting of interbedded sands, silts, and gravels, derived from the erosion
of the upriver glacial deposits. The alluvial soils extend below the mapped modified land and
artificial fill within the project site area, based on our review of the subsurface conditions
encountered on other nearby projects, including the Williams Condo's to the north and the City of
Renton Parking Structure to the south.
Geo Group Northwest investigated the subsurface conditions of the project site by drilling three
borings on May 26, 2004. The borings were located in the middle (Boring B-1), south (Boring B-
2), and north end (Boring B-3) of the property, approximately as shown on the Site Plan, Plate 2.
The total depth of the borings varied from 29 to 34 feet. Boring B-1 was drilled between the
material storage sheds and was terminated at a depth of 34 feet in dense Sand. Boring B-2 was
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terminated at a depth of 30 feet due encountering a naturally deposited wood log that could not
be drill through (refusal). Boring B-3 was terminated at a depth of 29 feet in a dense soil zone
greater than 10 feet in thickness.
� The soil and groundwater conditions encountered were logged by an engineering geologist from
� Geo Group Northwest. Standard penetration tests and soil samples were collected at 2.5 to 5
i
� foot intervals, as indicated on the Boring Logs in Appendix A. The Soil samples were analyzed
i , for moisture content in our laboratory and the results are recorded on the Boring Logs.
I
In general, the soils in the upper 9.5 feet to 12.5 feet consist of loose/soft fill and silty alluvial
sediments. The fill at the north end of the site was about 8.5 feet thick and contains concrete
rubble. Below the upper loose/soft soil zone the soils encountered consisted of inedium dense to
dense alluvial interbedded silty sands, silts, and gravels. For a more complete description of the
soils encountered, please refer to the Boring Logs in Appendix A.
I 2.3 GROUNDWATER CONDITIONS
�I
II Water was encountered below a depth of about 17.5 feet in the middle and southern portion of
the site and at a depth of 22 feet (�) below the ground surface at the north end of the site.
Moderate perched seepage was encountered in the fill at depths of 3 to 5 feet at the north end of
the site. Seepage and the groundwater table elevation may fluctuate seasonally depending on the
flow and recharge rates of the Cedar River and on precipitation.
3.0 SEISNIICITY
3.1 LIQUEFACTION
Liquefaction is a phenomenon where loose, granular, cohesionless soil below the water table �
temporarily loses strength and behaves as a liquid due to strong shaking or vibrations, such as
those that occur during earthquakes. Clean, loose and saturated granular soils, such as uniformly �,
graded, fine-grained sands and non-plastic silts that lie within 50 feet of the ground surface are �
susceptible to liquefaction. The result of soil liquefaction can include ground settlement, sand I
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boils, and lateral spreading.
The site soils below the water table (17.5 feet f) are medium dense to dense with occasional thin
layers of loose Sand and medium stiff Silt. Based on the encountered subsurface site conditions,
the liquefaction potential for the site is low due to the medium dense to dense nature of the soils
below the water table, the silt content of the soils, and the limited thickness of the loose
interbedded saturated sands.
3.2 GROUND MOTION
Based on the subsurface conditions encountered, anticipated damage to the proposed structure
would be caused by the intensity and accelerations caused by a strong motion earthquake and not
by liquefaction or lateral movement of the site soils. The building will be supported on either
piles, short aggregate piers, or on suitable bearing soils and no structural mitigation measures are ��,
required to address liquefaction or lateral spreading phenomena.
3.3 UBC Classification
The 1997 Uniform Building Code (UBC), classifies western Washington as Seismic Zone 3
(Figure 16-2), and assigns a Seismic Zone Factor, Z, of 0.30 (Table 16-I). The site soils
encountered best conespond to a Soil Profile Type of SD - Stiff Soil Profile Type (Table 16-J).
Based on a Seismic Zone Factor(Z) of 0.3 and a Soil Profile Type of SD, the Seismic Coefficient
Ca is 0.36 (Table 16-Q) and the Seismic Coefficient Cv is 0.54 (Table 16-R) for the site.
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4.0 DISCUSSIONS AND RECOMMENDATIONS
4.1 GE1vERaL
Building column loads of 200 to 350 Kips, with short-term seismic loads up to 400 Kips, are
anticipated, based on preliminary calculations by the structural engineer, Mr. Mark Moorleghen of
DCI Engineers. Based on the subsurface conditions, the proposed buildings may be supported on
concrete piles, helical anchors, short aggregate piers(also referred to as GeopiersTM or Stone
Columns), or the unsuitable soils may be over-excavated and replaced with structural fill or lean-
mix concrete. Over-excavation will require temporary shoring if 1H:1 V open cuts can not be
made due to property line or other restraints. The parking gazage will be excavated to a depth of
about 8 feet and temporary shoring may be required.
Structural fill below the foundation elements should extend down and out from the footings
creating a 1H:2V structural prism below the footings. This will require a wider excavation which
could encroach beyond the property line(s). Temporary shoring should be designed for an over-
excavation depth of up to 13 feet. It may be fea,sible to incorporate sections of the shoring piles �
into the perimeter support for building if the shoring is structurally designed as such. I
Slab-on-grade floors for the building and parking garage should be structurally supported if the '
building is pile or helical anchor supported. Regular non-structural floor slabs may be used if the
subgrade is improved with short aggregate piers or the loose/soft soil encountered in the upper 10
feet (�) is replaced with structural fill.
4.2 SITE PREPARATION AND GENERAL EARTHWORK
4.2.1 Temporary Erosion Control
The site soils are moisture sensitive and temporary erosion control measures, such as perimeter ,
silt fencing, should be installed prior to the start of grading and construction. Filtration fabric
sock should be installed in the stormwater catchbasins adjacent to the site. A crushed rock
construction entrance may be required to mitigate the tracking of mud on the street. Exposed site
soils should be covered with straw mulch during wet weather and surface runoff should not be
allowed to flow uncontrolled into excavation areas. During wet weather it may be necessary to
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Geotechnical Engineering Study
cover cut slopes with plastic sheeting to minimize erosion.
4.2.2 Excavations and Slopes
Temporary open cuts may be used excavate for the parking garage or to over-excavate and
replace the unsuitable soils in the top 10 feet, provided there is available space or a temporary ',
encroachment agreement with the adjacent property owners is obtained. The stability of
temporary cut slopes is a function of many factors, including soil type, geometry, surcharge loads,
amount of time the cut is open, and the presence of subsurface seepage. It is the responsibility of
the contractor to maintain safe slope configurations. Excavations should not intrude into a 1H:1V i
imaginary plane e�ending below the foundations of the adjacent buildings starting 5 feet out from ;
the building. If groundwater seepage is encountered, excavation of cut slopes should be halted
and the stability of the cut slope evaluated by the geotechnical engineer.
Temporary cuts greater than four feet in depth should be sloped at an inclination no steeper than i
1 H:1 V (Horizontal:Vertical). If cuts of this inclination or less and greater than four(4) in height I
can not be made due to property line or other restraints then temporary shoring will be required.
Permanent cut and fill slopes should be inclined no steeper than 2H:1 V.
4.2.3 Site Soils, Subgrade Stabilization & Concrete Rubble I'
The site soils contain silt, are moisture sensitive, and should not be used as structural fill unless
approved by the geotechnical engineer. During wet weather protection of the subgrade may be
required to provide a stable subgrade for drilling and construction equipment. It may be
necessary to cover the site with two to four-inch size crushed rock or recycled concrete to
provide a stable subgrade base for the contractors. Subgrade stabilization recommendations
should be provided by geotechnical engineer based on the site conditions.
In Boring B-3 at the north end of the site, the fill was about 8.5 feet thick and the concrete rubble
was encountered at a depth of 4 to 6 feet. The e�ent and condition of the fill may vary and
removal of the rubble may be required prior to or during the drilling of piles.
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4.2.4 Structural Fill
Fill material used to support building foundations, slab-on-grade floors, pavements and sidewalks
should meet the requirements for structural fill. We recommend using imported granular soils for
structural fill, such as a sand and gravel pit-run. During dry weather, any compactable non-
organic soil may be used as structural fill, provided the material is near the optimum moisture
content for compaction purposes and achieves the compaction specifications. During wet
weather, material to be used as structural fill should have the following specifications:
l. Be free draining, granular material, which contains no more than 5 percent fines (silt and
clay-size particles passing the No. 200 mesh sieve};
2. Be free of organic and other deleterious substances;
3. Have a maximum size of three-inches.
Structural fill material should be placed at or near the materials optimum moisture content. The
optimum moisture content is the water content in soil that enables the soil to be compacted to the
highest dry density for a given compaction effort. Structural fill should be placed in thin
horizontal lifts not exceeding 10-inches in loose thickness. Under building foundations and slab-
on-grade floors, structural fill should be compacted to at least 95 percent ma�mum density, as
determined by ASTM Test Designation D-1557-91 (Modified Proctor). Under pavements
structural fill should be compacted to at least 90 percent maacimum dry density, with the exception
of the top 12-inches which should be compacted to at least 95 percent maXimum dry density. We
recommend granular fill materials be compacted with vibratory compaction equipment, such as a
vibratory drum roller or hoe-pack.
4.3 TEMPORARY EXCAVATION SHORING
_ Temporary excavation shoring may be needed to support the excavation along the properry lines
to prevent encroachment onto the neighboring property or prevent excavation impacts to the
building foundations on the adjoining properties.
! Temporary excavation shoring may consist of a cantilever soldier pile and lagging wall. Where
' the excavation limits are setback from the property lines, it may be possible to limit the height of
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Geotechnical Engineering Study
the shoring by using a 1H:1 V inclined open cut above the shoring. The shoring should be
monitored and, if applicable, the adjacent building monitored for movement during construction
by surveying select points on a weekly basis. Prior to the start of construction, the adjacent
buildings, pavements, and sidewalks should be surveyed and any cracks, sags, or other damage
documented to protect against unwarranted damage claims.
A cantilever soldier pile and lagging wall may be economical for temporary shoring walls up to 12
feet (f) in height. Soldier piles are first installed by setting and grouting steel beams in pre-drilled
holes. If the piles extend below the water table the holes should be drilled using the augercast
method which allows the hole to be filled with cement grout as the auger is e�racted to minimize
groundwater intrusion and prevent collapse of the hole. The site excavation in front of the wall
would then be carried out in about 4-foot excavation lifts to allow installation of timber lagging
behind the soldier piles.
Shoring Design Criteria:
Active Soil Pressure 35 pcf equivalent fluid weight for level ground behind the wall,
(Add l OH psf for permanent shoring seismic considerations)
Allowable Passive Soil Pressure: 300 pcf equivalent fluid pressure above the water table and
200 pcf equivalent fluid pressure below the water table
The active soil pressure should act on one pile-spacing above the excavation line and one pile-
diameter below. To counter the active soil pressure, the allowable passive soil pressure below the
excavation line acting on one pile-spacing or two pile-diameters, whichever is less, may be used.
For sloped ground behind the wall, a surcharge load equivalent to 50 percent of the soil height
above the wall should be considered in addition to the above active soil pressure. Traffic and
adjacent building surcharges should also be accounted for.
Due to soil arching effects, timber lagging for the temporary shoring system should consist of
pressure treated timber designed to resist 50 percent of the apparent lateral soil pressure.
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4.4 FOUNDATIONS
Loose/soft soils that could settle under load are present in the upper 9.5 feet to 12.5 feet of the
site. The following options may be considered for supporting the building structure:
1. Augercast piles
2. Helical anchors
3. Short aggregate piers
4. Over-excavation and replacement with structural fill or lean-mix concrete
4.4.1 Augercast Piles
Augercast piles may be used to transfer the building loads through the loose sands and soft silts,
into the denser sand, silt, and gravel alluvial material. The following table provides allowable
axial and lateral loading for piles of varying diameter and length. The size, number, spacing, steel
reinforcement, and grade beam requirements should be designed by the structural engineer. The I,
following recommended allowable design parameters assume that the pile caps are tied together �'i
with grade beams and the piles are adequately reinforced to resist shear loads. �,
Pile Pile Pile Allowable Lateral Allowable Allowable III
Diameter Length Embedment Load for 114 inch Aaial Loading Uplift �i
(inches feet feet Deflection tons (tons) (tons)
14 20 10 2 35 17.5 �,
30 20 2 54 27 I
16 20 10 2.5 44 22 �
30 20 2.5 67 33.5
18 20 10 3 54 27
30 20 3 81 40.5
24 20 10 4 92 46
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No reduction in pile capacity is required if the pile spacing is at least three times the pile diameter.
A one-third increase in the above allowable pile capacities can be used when considering short-
term transitory wind or seismic loads. Lateral forces can also be resisted by the passive earth
pressures acting on the grade beams, and friction between the grade beams and the subgrade. To
fully mobilize the passive pressure resistance, the grade beams must be poured "neat" against
compacted fill. Our reconunended allowable passive soil pressure for lateral resistance is 300 pcf
equivalent fluid weight. A coef�icient of friction of 0.35 may be used between the subgrade and
the grade beams. Anticipated post-construction settlement of augercast pile supported structures
will generally be on the order of 1/2 inch or less, with similar dif�erential settlement across the
building width.
The performance of piles depends on how and to what bearing stratum the piles are installed. It is
critical that judgement and experience be used as a basis for determining the embedment length
and acceptability of each pile. Therefore, we recommend that Geo Group Northwest, Inc. be
retained to monitor the pile installation operation, collect and interpret installation data, and verify
suitable bearing stratum. ,
4.4.2 Helical Anchors I
Helical anchors, developed by the A. B. Chance Company and Atlas Systems, Inc., consist of a
i
steel square shaft with one or more helices on the anchor shaft. Vertical bearing and tensile ,'
capacities have been calculated for three different helical anchor designs: a single 8-inch helix
anchor, a single 10-inch helix anchor, and a multiple helix anchor. The multiple helix anchor,
Chance Anchor C150 0007 or Atlas AHP-150-8/10/12, consists ofone 8-, 10-, and 12-inch
diameter helix spaced three-diameters apart.
I
Vertically installed helical anchors provide negligible lateral resistance for wind and seismic
loading. Lateral loads can be resisted by installing additional helical anchors at an inclination of
30 degrees with respect to the vertical.
The following table contains the allowable theoretical calculated capacities for helical anchors ,
installed at an inclination of 90° with respect to the horizontal, with a minimum embedment length �'
of 12 feet below the surface, and with a factor of safety of 2 with respect to the ultimate capacity.
Geo Group Northwest, Inc. ;
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The ultimate capacity for lielical anchors should be determined and verified in the field based on
the installation torque. The calculated theoretical allowable capacities are applicable for both
compression and tension.
Allowable Theoretical Verticai Bearing (Compressive) and Tensile Load (Shear)
Capacity of Helical Anchor
Installation 12 Inch 14 Inch 10-12 Inch 8-10-12 Inch
Depth to Diameter Diameter Diameter Diameter
Largest Helix Single Helix* Single Helix* Double Helix* Triple Helix*
12 feet 10.2 tons 12.7 tons 17.3 tons 21.8 tons
15 feet 12.8 tons 15.9 tons 21.7 tons 27.4 tons
*The factored nominal loads must not exceed the anchor design strengths. Design strengths for
multiple helix Chance Anchors have maximum design strengths of up to 50 kips (25 tons), or less,
as noted in Tables 1 and 2 of ICBO Evaluation Report No. ER-5110.
The ultimate capacity for helical anchors should be determined and verified in the field
based on the installation torque and test loading of a minimum of three piles to verify the
calculated bearing capacity. For Chance helical anchors, the ultimate capacity can be
deternuned by the following empirical relationship: Q�T= IC� * T
where: K, is the empirical factor (= 10 ft"' for square shaft anchors); and II
T is the installation torque.
;
'
The allowable capacity of the Chance helical anchor may also be developed when sufficient torque
is recorded during installation. For example, based on the empirical conelation developed by the
A. B. Chance Company, an installation torque of 4,000 ft-lbs roughly conelates to an ultimate
capacity of 20 tons. The allowable capacity for the installed anchor with a factor of safety of 2
with respect to its ultimate capacity is approximately 10 tons. ,
rade beams. The ade beams II'�
Lateral forces exerted parallel to the slope face can be res�sted by g gr
should form a lattice anangement to minimize lateral movements of the structure. Alternatively,
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additional inclined helical anchors can be installed perpendicular to the first set of inclined anchors
in order to minimize lateral movements.
4.4.3 Short Aggregate Piers
Highly compacted short aggregate piers may be used to sti�en the upper softJloose soils and ,
allow conventional spread footing foundations to be supported on the short aggregate piers with
tolerable settlements. Geopiers"" is a patented ground improvement method, developed as an
alternative to deep pile foundations, preloading, and the over-excavation/replacement technique
commonly utilized to improve bearing soils beneath shallow foundations. Short aggregate piers
are installed by drilling a pattern of holes below footings and slab-on-grade floors to create
vertical columns. Short aggregate piers are typically 2 to 3 feet in diameter. The height of an
aggregate pier is typically two to three times its diameter or width, and typically covers 25 to 35
percent of the foundation contact area. The soils at the bottom of the pier are first densified by
impacting them with a hydraulic tamper that utilizes a beveled head. Crushed aggregate is then
� placed and compacted in thin lifts to create an aggregate column. The tamping process pre-
stresses the soil vertically and horizontally resulting in an enhanced matrix soil. The stiffness and
support capacity of the soil is significantly improved and the effect of the structural loads are
therefore reduced. Based on project histories, building settlements can be reduced to one inch, or
less to achieve allowable bearing capacities in the range of 3,000 psf to 5,000 psf. Short
aggregate pier design requires engineering to determine the size, height and spacing requirements
within acceptable settlement limits. Engineering is typically provided by the pier contractor.
4.3.4 Conventional Spread Footing Foundations
The building(s) may be supported on conventional spread footings consisting of individual
column/pier footings and/or strip footings if the building foundations are supported on structural
fill or lean-mix that e�ctends down to suitable bearing soils or if foundations are supported on short
aggregate piers. We recommend the following spread footing design parameters:
• Allowable bearing pressure, including a11 dead and live loads
- Structural fill, lean-mix, short aggregate piers = 3,000 psf
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• Minimum depth to bottom of perimeter footing below
adjacent final exterior grade = 18 inches
• Minimum depth to bottom of interior footings below
top of parking slab = 18 inches
• Minimum width of wall footings = 16 inches
• Minimum lateral dimension of column footings = 24 inches
• Estimated post-construction settlement:
- Over-excavation & replacement with structural fill or lean-mix = 1/2 inch
- Short Aggregate Piers: To be determined by pier designer
• Estimated post-construction differential settlement across building width:
- Over-excavation & replacement with structural fill or lean-mix = 1/2 inch
- Short Aggregate Piers: To be determined by pier designer
A one-third increase in the allowable bearing pressures can be used when considering short-term I
transitory wind or seismic loads. Lateral loads can also be resisted by friction between the
foundation and the suppoRing subgrade or by passive earth pressure acting on the buried portions
of the foundations. For the latter, the foundations must be poured "neat" against the existing
undisturbed soil or backfilled with a compacted structural fill. For lateral pressure considerations,
we recommend a passive pressure of 300 pcf equivalent fluid weight and a coefficient of friction
of 0.35.
4.5 PERMANENT BASEMENT AND CONVENTIONAL RETAIMNG WALLS
Basement and retaining walls restrained horizontally on top are considered unyielding and should
be designed for a lateral soil pressure under the at-rest condition; while conventional reinforced
concrete walls free to rotate on top should be designed for an active lateral soil pressure.
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Active Earth Pressure
Conventional reinforced concrete walls that are designed to yield an amount equal to 0.002
times the wall height, should be designed to resist the lateral earth pressure imposed by an
equivalent fluid with a unit weight of 35 pcf for level backfill above the wall.
At-Rest Earth Pressure
Walls supported horizontally by floor slabs are considered unyielding and should be designed
for lateral soil pressure under the at-rest condition. The design lateral soil pressure should
have an equivalent fluid pressure of 50 pcf for level ground behind unyielding walls.
Traffic and planter loads, if applicable, should be considered in addition to the above soil
pressures. Recommended passive and base coefficient of friction:
Passive Earth Pressure
• 300 pcf eyuivalent fluid weight
Base Coet�icient of Friction
• 0.30
The walls should be drained to prevent the buildup of hydrostatic pressure. We recommend using
a vertical drain mat and granular free-draining backfill material to facilitate drainage as discussed
in the Drainage section.
4.6 SLAB-ON-GRADE FLOORS
If the building is supported on augercast piles, it will be necessary to structurally support the
bottom floor slab with the grade beams that span between the augercast piles. If the slab
subgrade soils are improved by installing short aggregate piers or over-excavating and replacing
the unsuitable soils, a regular non-structural floor slab may be used.
Slab-on-grade floors underlying heated living areas, utility rooms, and dry storage space should be
poured on top of a capillary break to mitigate the wicking of moisture up through the soils to the
slab. The capillary break should consist of a minimum of six(6) inch thick layer of free-draining
gravel containing no more than five (5} percent finer than No. 4 (1/4-inch) sieve, or clean crushed
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Geotechnical Engineering Study
rock. To reduce water vapor transmission through the slab we recommend installing a 10-mil
reinforced vapor barrier between the capillary break and concrete floor slab, such as Moistop� by
Fortifiber Corporation. Two to four inches of sand may be placed over the membrane for
protection during construction.
4.7 DRAINAGE
4.7.1 Surface Drainage
The finished gound at the site should be graded such that surface water is directed away from the
building structure. Water should not be allowed to stand in areas where footings, slabs or
pavements are to be constructed.
4.7.2 Footing Drains
We recommend that footing drains be installed around the perimeter foundation. The drains
should consist of a four (4) inch minimum diameter, perforated or slotted, rigid drain pipe laid at
or near the bottom of the footings or grade beams with a gradient sufficient to generate flow, as
illustrated on Plate 3, Drainage Detail. The drain line should be bedded on, surrounded by, and
covered with a free-draining rock or free-draining granular material. The drain rock and drain line
should be surrounded by a geote�ile filter fabric, Mirafi 140N or equivalent.
Roof drains should be separately tightlined to discharge into the storm water collection system
and should not be connected to the footing drain system. Cleanouts should be installed to allow
for periodic maintenance of the footing drains and roof downspout tightline systems.
4.7.3 Basement Wall Drainage
The exterior of basement walls (parking garage) should be sealed and a vertical drain mat
installed, such as Miradrain 6000 or equivalent, to facilitate drainage. The drain mat should
e�end from the finished surface grade, down to the footing drain pipe and be secured to the wall.
The top of the drain mat should be pinned to the wall with a bar to prevent backfill soils from
entering between the wall and drain mat. Backfill the wall with a granular material, such as a pit-
run gravelly sand and compact to a minimum of 90 percent of the materials maximum dry density.
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The top twelve (12) inches of backfill should consist of a relatively impermeable soil. This cap
material can be separated from the underlying more granular drainage material by a layer of
geotextile.
4.8 PAVEMErrrs
The adequacy of a pavement performance is strictly related to the condition of the underlying soil
subgrade and rock base material. If this is inadequate, no matter what pavement section is
constructed, settlement or movement of the subgrade will be reflected up through the paving. In
order to avoid this situation, we recommend the subgrade be treated and prepared as described in
the Site Preparation and General Earthwork section of this report. Areas of soft, wet, or
unstable subgrade may still exist after this process. If so, over-excavation of the unsuitable
'� materials and their replacement with a compacted structural fill or crushed rock may be required.
� The pavement section design should consist of the following minimum material thicknesses:
M'in. Thickness
A. Class "B" Asphalt Concrete 3 - inches ,
Over 3/4-Inch Minus Crushed Rock Base 6 - inches '
B. Reinforced Concrete Slab 6 - inches '
Over 3/4-Inch Minus Crushed Rock Base 4 - inches �,
The minimum material thicknesses ma not be acce table if there is evidence of instabilit in the i�
Y P Y
subgrade. In the event of poor, yielding, or unstable subgrade conditions, Geo Group Northwest
should be requested to review the site conditions and provide subgrade stabilization
recommendations.
�
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Geo Group Northwest, Inc.
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5.0 LIMITATIONS
This report has been prepared for the specific application to the subject project site, for the
exclusive use of Friedman Development and the project design team. The findings and
recommendations stated herein are based on our field observations, the subsurface conditions
encountered in our site exploration, our experience, and judgement. The recommendations are
our professional opinion derived in a manner consistent with the level of care and skill ordinarily
exercised by other members of the profession currently practicing under similar conditions in this
area and within the budget constraint. No warranty is expressed or implied. In the event that soil
conditions vary during site work, Geo Group Northwest, Inc. should be notified and the
recommendations herein re-evaluated, and where necessary, be revised.
6.0 PLAN REVIEW AND CONSTRUCTION MONTI'ORING
It is recommended that we be retained to perform a general review of the final design and
specifications to verify that the earthwork, foundation, and other recommendations have been
properly interpreted and implemented in the design and engineering plan documents.
It is recommended that we be retained to provide geotechnical monitoring services during
construction. This will allow us to confirm that the subsurface conditions are consistent with
those described in this report and allow design changes in the event subsurface conditions differ
from those anticipated prior to the start of construction. It will allow us to evaluate whether the
erosion control, earthwork, and foundation construction activities conform to the intent of the
contract plans and specifications. While on the site during construction, we will not direct or
supervise the contractor or the contractors work, nor will we be responsible for providing or
reviewing on-site safety or dimensional measurements.
INSPECTIONS
The following items should be inspected by the geotechnical engineering firm during
construction:
• Installation of piles, anchors, and piers for foundation support;
• Installation of shoring;
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Geotechnical Engineering Study ,
• Excavation and subgrade improvement, including installation of short aggregate piers; !
• Structural fill placement and compaction testing; �
• Soil bearing verification for spread footing foundations and slab-on-grade floors;
• Subsurface drainage installation;
• Subgade preparation for pavements, proof-rolling, and subgrade stabilization i
The contractor should provide a minimum of 24 hours advance notice to perform the above
inspections so that we can arrange to have personnel available.
We appreciate the opportunity to provide you with this geotechnical engineering study. Please
contact us if you have any questions regarding this report or if additional information is needed.
Respectfully Submitted, ot w a s hi,�
GEO GROUP NORTHWEST, 1NC. .,'�� 9�c
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Wade J. Lassey ��sed Gz��o
Engineering Geologist wg��J. l.�ssey
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William Chang, P.E. ,�~�,°� �'��`�c
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EXPIRES: 2/19/
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LEGEND
BORING NUMBER&
B_1 APPROXIMATE LOC.
SITE PLAN
MERRILL GARDENS AT RENTON CENTRE
'This site plan adapted from a Site Sketch by C �NTON WASHINGTON
CfII� WC JOB NO. G-1812 PLATE 2
Basemerrt
Wall
Slope to drain `
Vertical Drain Mat
0 0 � o (Mamdrarn 6000
0
o O or equivalentJ
o a o O
� O ' o FRE�DRAININGo
BACgFILL MATERIAL '
l � o (Compacted tv 90%Max I
0
� � DryDensity) I
/�\\ o 0
o �
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� 0 0 0
0
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5
U �� �.nn��'rr:.�'� .� .;.� �.; . ..r.�.�
. ,'.'. S�'.� �. .
O �.'.'.'.'.'.'.'.•.'.'.'.'.•.'.'.•.'.... . • . . . - .� .- .. .. . �.. :'.::
� '. _ . . . . . .. :.... ....
� � �'�'�'�:�:�:�:�:�:�'�:�:�:�'�:�'�'�:�:-:�:�:.: - GRAVELDRRINMAT I
C �~ f:�:����=���������'�������:�::=:�::.�.�.�.�.�.�. � � ,
.•.•:.• �F'DOTI_�iG c.�n.raRra�a,e '
7 � ���::: ''� '
��:�::� ���
FOOTING DXAIN '
GEOTE�77LE Lfinimum 4-inch diameter rigid slotted, or
FILTER Fr1BRIC perfomted PVC pipe with positive gradient to
(Mrmfi 140 N, or discha�ge
equivalettt)
Free Draining Matenal
(Washed grave!)
NOT TO SCALE
NOTES:
1.) Do not replace rigid PVC pipe with fle�ciible corrugated plastic pipe.
2.) Perforated or slotted PVC pipe should be tight jointed and laid with
perforations or slots down,with positive gradient to discharge.
3.) Do not connect roof downspout drains into the footing drain or under slab drain system.
4.) Basement wall bacl�ill to be compacted to 90°/a of maximum dry density based on
Modified Proctor(ASTM D-1557-91). The top 12-inches to be compacted
to 95%of maximum dry density if backfill is to support sidewalks, driveway, etc.
_
TYPICAL BASEMENT WALL AND
- FOOTING DRAIN DETAIL
� Group Northwest, Inc.
� Geotechnical Engineers,Geologsts,8 MERRILL GARDENS AT RENTON CENTRE
EnvronmaMal Sciem'sts
RENTON WASHINGTON
SCALE NONE DATE 6/11/O4 HADE W.TL CIiKD WC JOBlYO. G-LHIZ PLr1TE 3
i '
APPENDIX A
BORING LOGS
G1812
Geo Group Northwest, Inc.
LEGEIND OF SOIL CLASSIFiCAT1�N AND PENETRATiON TEST
UNIFIED SOIL CLASSiFlCAT10N SYSTEM (USCS)
i
�woR n� I � ; rr�cu u�scx�noN �naoRa�r ci.asa+t�canoN cserre�u
? WB.L GRAO�GRAVBS,GRAVgSAPD Cu=(OBO/U1�g�saoer ttan 4
�µ '� MDCTURE.LlTTLE OR NO FlI�FS DEfE3tMINE �=i��)�(��'�1 heM�een 1 and 3
GRAVBS
PEftCBiTAGES OF
GRAVBS (litlls or no POORLY GRAO�GRAVB S�AND GRANaSMO GRAVEl AND SA1�
(Ma�71w�FWf � tin� � � t�CRJitES LITTLE OR NO IaNES FitOM GR/UN Sf�� NOT MEET1iG A80VE REQU�TS
��� ���s DIS'iR1BlJilON
GRN�S014S �y�Than Na 4 CURVE AT18t8HZG LYYTS B�OW
4 �� � GY I 3LTV GRAVELS.GRA1f�SM6SLT MDCTURES � � ar P.L LESS THAN 4
I (wilh sortfs i CLAYE/GRAVBS,GRAVH.SAND�CLAY i D(L�612X A7TStBERG Lll1M'i5 ABOVE
� i � MDCRJRES I COARSE GRAW�I 'A'IJNE
� SOILS ARE a P.L MO(tETHAN 7
i �� CLFAN Syy � VYEll Gi3ADED SAPAS.GRAVaLY SANDS, �� (:�+_(D90/Dt�gnrertlian 8
� LtTTLE OR NO RNES Co=(D00�)�1D90•DEO�bMwaen 1 and 3
���� ar ro POOftLY GRADED SAI�S�GRANBLY SIWD6, �5A�F�s Gedr�
Coarss Giains � i
Than FWf i1 � U1T1�OR NO i�tES GYV.OP�SW,SP NOT MEEfWG ABOVE f7EWRH�AB�ITS
yy���y� Srt�aWs►Than No. f�^°6)
Than Na 200 �S�O'�� >12%Fne Gr�ina� ATT6Z8B2G UMfTS BELOW
� p�iT/ SM SILTY SAND3.SANDSILT I�Ci1JRE3 GM,GG�M.SC CONTENI'OF �A'Lll�
�pg wilh P.LLESSTHAN 4
RWES
! i 5 m 12%Fne p�C�pg�� ATTE3298tG LII�MTS ABWE
��° ' SC CLAYEY SANDS,SA�D-ClJ1Y UADCTIRtES Caaii�usa dual "A'IJHE
�� i symyds wiih P.L MOREIHAN 7
I
� Si.TS Liqwd Limit i alORGAPNC SILT3.ROpc RaIR,SANOY 91T5
, �p�,q,�,j�� <5Q% � � dF SUGHT PU1S't1CaTY �
; p}�j�y�yR � Pl./15TlQTY CHART MLin��
Fln�-cR� � �� t.;�u;��,,,e � � eaRc��c s�zs.�cncEous oR � � ��P�s� �
sa�s ��) >sos oU7a�ous.a�s�rmr oa si�rv so� i r�o.�o s� ai a oH
, � ' ;
I r�oRc�wic a.�rs oF ww�.nsrlatt, x�o
anrs w�� cL cw►val.r.siwor.oR sa.rr curs,csF�n W I I
� ��°" `� � CLAYS Z +
! �� Liquid Lsnit PIORGMIIC CU1YS OF HIGH PLASTICfTY.FAT F�
� �� >� � (�ys U CL ar OL I
F- �
Mors Tlwn Half �
Wei9���7� Lquid Limit ` p� ORGANC Sq.TS AND ORGANIC SLTY CUYS OF � MH ar OH
Than No.100 ���� <Sp�1 ! LOW PLASTIClTY
�w CUYS 10
I �� �� � OFI ORGANIC C1.Al/S OF Fi1G}I PL.AST1CTiY ♦ � � �
0
0 �0 20 30 �0 50 BO 70 80 90 100 1'10
FIK�Y ORGAf�MC SOLS I R PEI1T AND QTHE32 HIGFILY ORGIINC SOLS � LIGUID IJMT(%)
(
SOIL PARTICL.E Si� GEMERAL GU�OMICE OF SOIL ENGINE�RING
U.S.STANWIRD StEYE PROPHtTIES FROM STANOARD P@IETRATION TEST(SP'� I
FR11�710N Passi�y Rdaa�ed SANDY SOLS SILTY 8 CLAYEY SOILS '
�Ze Sfm� u�md�+ea
I stwa ��) sieva (�! cowNa o.n�/ �ngl. ' �sscriptlon caue�s 1 �"�' �s�r�p4�
i
SILT!CLAY � f/200 QO75 N 9� b.degias N � qu,trQ
i
SAND i 0-4 � 0-15 i Wry k�os� <2 � <0.25 Very saR
FINE �MD � Q4�i i/700 I Q075 4-10 15-35 2E-30 Loo�s 2-4 Q25-450 f SaR
MEDIUM �10 � 200 #W I 0.125 10-30 �-Q6 28-35 Medixn Oenia l-8 QSD-1.OD I Medi�rn S6R
COARSE t1 i 4.75 S10 200 30-50 �-85 35-42 Deera 8-�5 1.00-200 � StiR
ORAVEL >50 �-100 1 38-49 Very Dense 15-30 I 20�-4.00 i Very S'tlR
FlNE �9 1M 1.75 � >30 I >4.00 Hard
CON2SE 7a � 19 -�
COBBLES ' 76 mm bo 209 rrvn
� ,�� � Group Northwest, Inc.
- GsobchnicalEnginsers.Gaobqsri.3
Rp�x � ��� Envoommer�ISciaM{�b
���� j 19240 NE 2Dth Stree�Suib�12 8dlewe,WA 98005
reocx ' >o.�e��„�+�bw�„e �c•�s�e.s.srsi �c��� P LATE A 1
BORING NO. B-1 '
Logged By: WJL Date Drilled: 5/26/04 Surface Elev. feet+/- ��,
Depth SAMPLE
sPT(I� water Drilling/sampling
�R� uscs Soil Description Blo.�r� �°�t �t'�an�
(_�� % Obsetvations
Type No.
2" Asphalt
�" � S l 2,2, 1 29.3
Sandv SILT.SAND&SILT,mottled brown to
5 --- N=3
brown,fine sand, soft to medium stiff silt&very T
SP-SM loose sand, damp to moist 1 s2 t,o,i s.s
N=1
jy�� T S3 2,2,3 393
_1_. J�_5 Harder drilling at 9.5
�o - - - - - - - - - - - - - - - I f�t
S4 19,24,26 23.1
N=50
SS 38,38,28 3.4
ls GP- GRAVEL,with sand,fine to coarse, dense to N=66
GW medium dense,damp to wet
IS6 11,14,12 10.3 Water encountered at
20 N=26
_ _ _ _ _ _ _ _ _ _ _ _ _ _ 17.Sfeetbgs(+/_)
MI- SII,T,gray, some fine sand,medium stiff, wet � s7 3,2,3 3z.s
25 N=5
— _ _ _ _ _ _ _ _ _ _ _ _ _ _
ISS I5,16,21 19.2
so sW Gravelly SAND, gray,fine to coarse,dense,wet v-37
IS9 22,27,39 14.7 �countered Heave
35 N=66
Total Depth=34 feet
Boring Locarion: Middle of site
ao
Driller: R&R Drilling Co
Type:Hollow stem auger
JS
50
LEGEND: � 2-inch O.D.Split Sp��on Sample Interval :V: Number of blow counts for 1 foot of
Sampier ciriven with 14016.Hammer(Standard SPT') sampler advancement
= BORING LOG
-
� Group Northwest, Inc. MCLENDON HARDWARE PROPERTY
BURNETT AVENUE SOUTH
�� Geatechnical Engineers,Geobgisfs.8
��ironrrental scientists RENTON,WASHIZVGTON
JOB NO. G-1812 DATE 6/11/04 PLATE A2
BORING NU. B-2 '
Logged By: WJL Date Drilled: 5/26/04 Surface Elev. feet+/-
Depth SAMPLE SPT�) Water Drilling/Sampling
�n� uscs Soil Description sloWs rer C°°t� Int'oxmation&
6-inches % Observations
Type No.
3" Asphalt,Pit Run to 1.5'
� SILT, mottled brown to brown, so8 to stiff, some I si N3,6 zs.3
5 fine sand,damp to moist(FII..L?)
ISZ 7,�,� 23.5
N–14
IS3 3,2,1 21.9
10 N=3
IGravelly drilling at
S4 7,10,16 15.6 10 feet
Sandv GRAVEL,fine to coarse gravel,fine to N=26
GP medium sand,dense,damp I ss �,zo,20 3.s
15 N=40
——— ————————————————————
� S6 10,9,5 ���g Water encountered at
20 N=1a
SP& SAND& SILT,brown, medium coarse to fine, 17.5 feet bgs(+I-)
some gravel,medium dense,wet,with interbeds
MI" of inedium stiff silt
IS� 1,�,6 24.2
25 N=6
Wood Log @ 28 feet = S7 5016" 45.o Wood Log from 28
3o N-loo to 30 feet
Total Depth=30 feet(Refusal-Wood)
Boring Location: Middle of site
35
Driller: R&R Drilling Co
Type:Hollow stem auger
.�o
as
so
LEGEND: � 2-inch O.D.Split Spnon Sample Lrterval N: Number ofblow counts for 1 foot of I
Sampler driven with 140 lb.Hammer(Standazd SP1') sampler advancement.
= BORING LOG I'
� Group Northwest, II1C. MCLEI�TDON HARDWARE PROPERTY
�� BiJRNETT AVENUE SOUTH
� Geotechnical Engineers,Geobg�sts,8 j�i rj'j'ON,WAS��NGTON �
Fsvcon mental Scientists
JOB NO. G-1812 DATE 6/11/04 PLATE A3
�
BORING NO. B-3
Logged By: WJL Date Dnlled: 5/26/04 Surface Elev. feet+/-
D� Sr1MPLE S���) Water Drilling/Sampling
(ft) USCS Soil Description Blows per Content Information&
6-ind�s ^ra observations
Type No.
1" Asphalt
SILT&Siltv SAND dark gray,black to gray, I si Za,s,6 i9.2
5 ML, �=i i
&SM ���nd and debris,moist,concrete rubble, gray S2 Concrete rubble at 4
Si1Ty SAND with gravel mOist(FILL) to 6 feet
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ � S3 8,14,15 12.0
10
'.V=29
NII, SILT& Siltv SAND browq some gravel, � sa 6,s,a 29s
to SM medium stiff to medium dense,damp to moist v=�
——— —————————————
____ � SS la,ll,tl 16.3
15 --- N=22
ML Silt and Silty Sand, gray, interbedded,some
to SM gravel, medium stiff to dense,damp to moist
____________________ � S6 2,6,42 34.'7 �7Slatei encountered at
20 ——— N=48
��K� 22 feet bgs(+/_)
Sw-SM SAND, mottled brown, interbedded gravel lenses,
� S7 39,39,33 101
Zs SP-SM fine to coarse,some silt,dense,wet N-�2
IS7 8,14,22 25.6
30 N=36
Total Depth=29 feet
Boring Location: Nor[h end of site
35
Driller: R&R Drilling Co
Type:Hollow stem auger
30
d5
50
LEGEND: � 2-inch O.D.Split Spom►Sample Interval N: Number of blow counts for 1 foot of
Sampler driven with 1401b.Hatnmer(Standard SPT) sampler advancemenf.
= BORING LOG ',
91 Group Northwest, Inc. MCLENDON HARDWARE PROPERTY
�� BURNETT AVENUE SOUTH ,
� Geotechnical Fngineers,Geobgists,8 !
Environmenta�sciermsts RENTON,WASIIINGTON
JOB NO. G-1812 DATE 6/11/04 PLATE A4