HomeMy WebLinkAboutSWP272165(1) ' GEOTECHNICAL ENGINEERING REPORT
' CITY OF RENTON
RE C E I V ED
' MAY 1 7 174
' BUILDING DIVI310N
RENTON CENTER FRED MEYER
Renton, Washington
Prepared for
Fred Meyer
Construction Management Department
11 -07400-02
April, 1994
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RZA AGRA, Inc. a A G R A 1
Engineering & Environmental Services Earth & Environmental Group
1
Inc. Uite NE 122nd Way
RZA AG RA
' , Suite 100
Engineering & Environmental Services Kirkland, WA 98034-6918
(206) 820-4669
' FAX (206) 821-3914
29 April 1994 11-07400-02
' Fred Meyer
Construction Management Department
' P.O. Box 42121
Portland, Oregon 97242
' Attention: Ms. Jennifer Riboli
Subject: Geotechnical Engineering Report
Renton Center Fred Meyer
Renton, Washington
Dear Ms. Riboli:
We are pleased to present herein a copy of the above referenced report. This report presents the results
of our subsurface exploration program and geotechnical engineering study related to the foundation and
construction considerations for the proposed project. Verbal authorization to proceed with this study was
' provided by Jennifer Riboli on 23 March 1994.
Our field exploration encountered very soft to soft silts, interbedded with loose to medium dense sands and
silty sands to depths of 20 to roughly 35 feet below the existing ground surface. At greater depths the
borings penetrated into dense to very dense, wet, fine to coarse sands and gravelly sands with some silt
and gravel zones. A thin surficial zone of fill and asphalt blanket the site. The upper soils are suitable for
the support of only very lightly loaded shallow foundations. Heavier foundation loads should be supported
' by deeper systems such as piling, extended to bear on the very dense native soils disclosed at depth.
Alternatively a preload may be applied to the native soils in the building area to reduce post-construction
settlement.
' We appreciate this opportunity to be of service to you and we would be pleased to discuss the contents
' of this report or other aspects of the project with you at your convenience.
Respectfully submitted,
RZA AGRA, Inc.
rKurt D. Merriman, P.E.
Associate
A G R A
' Earth&Environmental Group
SUBSURFACE EXPLORATION AND
' GEOTECHNICAL ENGINEERING STUDY
Renton Center Fred Meyer
' Renton, Washington
Prepared for,
Fred Meyer
' Construction Management Department
P.O. Box 42121
' Portland, Oregon
Prepared by,
RZA AGRA, Inc.
I11335 N.E. 122nd Way, Suite 100
Kirkland, Washington 98034-6918
April 1994
' 11-07400-02
' TABLE OF CONTENTS
11-07400-02
' 1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.0 SITE AND PROJECT DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3.0 SUBSURFACE CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.0 CONCLUSIONS AND RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
' 4.1 Deep Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.1.1 Augercast Piles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.1.2 Steel Pipe Piles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1.3 Lateral Pile Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
' 4.1.4 Piling Installation . . . . . . . , . . • • • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.2 Preload Fill Recommendations 8
4.3 Shallow Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
' 4.4 Floors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.5 Backfilled Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
' 4.6 Drainage Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.7 Site Preparation and Grading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
' 4.8 Pavement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : . . . . . . . . . . . . . . . 15
4.9 Utility Considerations . . . . . . . . . . . . . . . 16
' 5.0 CLOSURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
' Figure 1 - Site and Exploration Plan
Appendix A - Subsurface Exploration Logs
' Appendix B - Laboratory Testing Procedures and Results
GEOTECHNICAL EXPLORATION REPORT 11-07400-02
RENTON CENTER FRED MEYER
' RENTON, WASHINGTON
1.0 INTRODUCTION
This report presents the results of our subsurface exploration program and geotechnical engineering study
' for the proposed project. The project site and surrounding area are shown on Figure 1, Site Vicinity Map.
The proposed development and approximate locations of the explorations completed for this study are
presented on the Site and Exploration Plan, Figure 2.
The purpose of this study was to identify general subsurface conditions at the site so that conclusions and
' recommendations for foundation design and construction could be formulated. The scope of work consisted
of field explorations, laboratory testing and geotechnical engineering analysis. A brief summary of the
geotechnical considerations for the project is presented below:
The existing shopping center includes two anchor department stores (Sears and JC
' Penney) as well as two intervening smaller shop buildings (Buildings A and B). To the
south and east are additional small shop buildings. The shopping center is surrounded by
' asphalt paved parking.
• Redevelopment of the shopping center would include the construction of a new Fred Meyer
' Store as an anchor department store; additional space would be provided for a future
tenant in the southern part of the site.
Maximum anticipated new column loads may be on the order of 104 kips each. Walls may
impose loads of 3.1 kips per linear foot. Floor loading of up to 200 pounds per square foot
' may also be developed. Site grades will be raised approximately 2 feet for the new
building.
• The relatively loose and soft near surface site soils are not adequate for the support of the
' anticipated loads unless appreciable settlements can be tolerated. We recommend heavy
column loads in the new construction be supported by either augercast piling or a driven
' steel pipe pile foundation system. Alternatively, a preload would allow use of spread
footings and slab-on-grade.
The depth to bearing soils for pile support varies across the site. 12-inch diameter
augercast piling penetrating 10 feet into the bearing horizon may be designed for an
allowable vertical capacity of 30 tons,which includes an allowance for downdrag in the soils
' above the bearing horizon. Driven pipe piling of the same diameter may be designed for
an allowable vertical capacity of 40 tons. The depth to the upper surface of the bearing
' Fred Meyer 11-07400-02
29 April 1994 Page 2
horizon increased towards the southeast and ranged from 15 to 30 feet at our exploration
' locations. A structural floor on pile foundations may be required, depending on grade
changes and settlement tolerance.
' As an alternative to pile foundations, preloading the building pad, in conjunction with
overexcavation and structural fill placement below building foundations, appears feasible.
' Assuming no significant grade changes, a preload height of 8 feet above finish slab grade
for a period of 8 weeks may be used. A 2,000 psf bearing value may be used, predicated
on 2 feet of structural fill below the footing. Special construction considerations will be
' necessary where the existing building (Building B) to remain abuts the new store.
Limited-use lightly loaded footings may be designed with a maximum allowable bearing
' pressure of 1,500 pounds per square foot. These shallow conventional footings should
however be supported by at least 2 feet of uniformly compacted 90 percent density
' (ASTM:D-1557) compacted structural fill.
In those areas where the existing asphalt parking lot surfacing is intact, it would be
' acceptable to install a new asphaltic concrete overlay no less than 1.5 inches in depth. In
those areas where the existing pavement is fractured, alligatored or otherwise undergoing
failure, the defective surfacing and underlying softer subsoil should be removed. The
resulting overexcavated area should be backfilled with 95 percent density (ASTM:D-1557)
compacted structural fill prior to repaving.
The above summary is presented for introductory purposes only and should be used in conjunction with
the full text of this report. Verbal authorization to proceed with this study was granted by Jennifer Riboli and
has been completed in general accordance with our proposal letter submitted to Fred Meyer. This report
' has been prepared for the exclusive use of Fred Meyer,their design team and agents,for specific application
to this project in accordance with generally accepted engineering practices.
' 2.0 SITE AND PROJECT DESCRIPTION
The subject site is a 28-acre parcel situated adjacent to the southwest corner of the intersection of Sunset
' Blvd. and Rainier Avenue South in Renton, Washington. The property is occupied by the existing shopping
center which contains roughly 318,000 square feet of floor space, surrounded by a 1,924 space parking lot.
' RZA AGRA, Inc. completed both preliminary geotechnical and Level II environmental studies at the Renton
' Center site (W-6717-1, 20 March 1990 and W-7400, 28 March 1991).
Fred Meyer 11-07400-02
29 April 1994 Page 3
This current study included drilling two additional test borings with a truck-mounted hollow stem power
auger in order to identify subsurface conditions for foundation and floor support design. The approximate
locations of the various test holes advanced for the earlier and this current study are shown on Figure 1.
' The locations of our test holes were established by tape and hand held compass from on-site features
identified on the site plan provided to us. The most recently completed borings were drilled on 28 March
1994 by a local exploration drilling company under subcontract to our firm. The drilling process involved
advancing a 33/s-inch inside diameter hollow stem auger with truck-mounted drill rig. During the drilling
process samples were generally obtained at 2.5-to 5-foot depth intervals. The borings were continuously
observed and logged by an engineer from our office.
' Disturbed but representative samples were obtained by using the Standard Penetration Test procedures as
described in ASTM:D-1586. This test and sampling method consists of driving a standard 2-inch outside
' diameter split barrel sampler a distance of 18 inches into the soil with a 140-pound hammer free falling a
distance of 18 inches. The number of blows for each 6-inch interval is recorded and the number of blows
' required to drive the sampler the final 12 inches is considered the Standard Penetration Resistance (N) or
blow count which is presented on the boring logs in Appendix A. If a total of 50 blows is recorded within
one 6-inch interval, the blow count is recorded as 50 blows for the number of inches of penetration. The
resistance, or "N" value, provides a measure of the relative density of granular soils or the relative
consistency of cohesive soils. These values are plotted on the attached boring logs.
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The soil samples obtained from the split barrel sampler were classified in the field and representative
' portions placed in water tight containers. The samples were then transported to our laboratory for further
visual classification and laboratory testing. Samples are generally saved for a period of 90 days unless
special arrangements are made.
Relatively undisturbed soil samples were also obtained during the drilling process. These samples were
' acquired by pushing a 3-inch outside diameter seamless steel Shelby tube into the soil by the hydraulic
system on the drill rig, in accordance with ASTM:D-1587. Since the thin wall tube is pushed rather than
driven, the sample obtained is considered relatively undisturbed. These samples were classified in the field
by examining each end prior to sealing with plastic caps. The samples were then transported to our
' laboratory where they were extruded for further classification and laboratory testing.
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Fred Meyer 11-07400-02
29 April 1994 Page 4
The groundwater conditions observed during the exploration program are indicated on the logs. The depth
to water was identified by observing the moisture condition of the samples or observing free water on the
sampling rods. It should be noted that fluctuations in the level of the groundwater may occur due to
variations in rainfall, river level, irrigation and other factors. Water levels were also noted during our prior
subsurface explorations at the site. These prior water level determinations were established by measurement
of observation wells.
The exploration logs presented in Appendix A are based on the drilling action observed, inspection of the
samples secured, laboratory test results and the field logs. The various types of soils are indicated as well
as the depths where the soils or characteristics of the soils changed. It should be noted that these changes
' may have been gradual and if the changes occurred between sample intervals they were interpreted.
3.0 SUBSURFACE CONDITIONS
At the time of our subsurface exploration program, the entire area immediately adjacent to the existing
shopping center which will be occupied by new construction was asphalt paved. At our test hole locations,
the pavement generally appeared to be approximately 2 to 31h inches in thickness. Beneath this surfacing,
the borings typically penetrated loose, moist to wet, fine to medium sand fill. This fill, at our test holes,
varied from approximately 0.5 feet to 4.5 feet in depth. Beneath the sand fill, the borings penetrated very
soft to soft and locally medium stiff, wet, sandy silt and silt. Interbedded with the silt strata were loose, silty
fine to medium sands. This zone extended to depths of approximately 7.5 feet to 20 feet below the existing
ground surface. At greater depths, the borings encountered medium dense to dense, wet to saturated,
sands and gravelly sands along the medium stiff silts to depths of approximately 20 feet to 30 feet below
the existing ground surface. At greater depths, the borings encountered dense to very dense sands and
sandy gravels.
Water was noted in the test borings at the time of drilling between 7 feet and 10.5 feet below the existing
' ground surface. The monitoring well in boring B-1 was determined to have a static water level on 5 March
1990 at a depth of 6 feet below the ground surface. It should be noted that groundwater conditions may
fluctuate due to variations in rainfall, irrigation, river level, or other land uses in the area.
4.0 CONCLUSIONS AND RECOMMENDATIONS
We understand that the project will involve the construction of a new 167,000 square foot concrete tilt-up
' or masonry retail department store building, including 6,000 square feet of retail tenant space. Construction
Fred Meyer 11-07400-02
29 April 1994 Page 5
is planned to be in the approximate location of the existing Sears building and adjacent small shop
buildings. We understand that site grades will be raised approximately two feet for the new structure. In
addition, space is provided for future tenants to the south. Based on our subsurface exploration program
' it is our opinion that conventional spread and continuous foundation elements founded on the existing site
soils would not perform satisfactorily for the proposed building. Settlements would likely be excessive due
' to consolidation of the existing silt soils. We have estimated that long-term total and differential settlements
on the order of 1 to 2 inches may occur in the new building areas as the result of new fill placement to raise
grades. Greater amounts of settlement are anticipated for new foundation and slab loadings. Presently
' some of the interior columns of the Sears building have apparently settled several inches, relative to general
floor slab level, for this reason. As an exception, lightly loaded footings which support store fronts may be
' supported by conventional shallow spread footings, provided some remedial soils work is performed as
outlined herein.
In order to develop support for the anticipated relatively large wall and column loads we recommend that
' either a deep foundation system be used or that a preload be applied to the existing site soils in the
proposed building area.
' 4.1 Deep Foundations
Two alternative deep foundation systems may be considered. In order to minimize the risk of inducing
ground vibrations during pile installation,we recommend the use of augercast piling for foundation support.
Alternatively, if such ground vibrations can be tolerated, driven steel piles may be considered. Based on
' our analysis, augercast or driven steel pipe piles should penetrate at least 10 feet into the bearing strata
present at a depth of approximately 15 to 30 feet beneath the site. Bearing strata depth increases to the
southeast. Based on the anticipated bearing depths, piles would be on the order of 25 to 40 feet in length.
4.1.1 Augercast Piles
rAugercast piling may be designed with a vertical allowable capacity of 30 tons if a 12-inch pile diameter is
assumed. The piling should be provided with a minimum group spacing of no less than three diameters,
' center to center. During actual pile installation the work should be scheduled so that at least 24 hours
elapses between drilling of adjacent piles in an individual pile cap. In this way"green" concrete is less likely
to be disturbed. In any case, augercast piles should be installed by a contractor who is experienced in the
technique. It will be essential for the contractor to maintain a continuous column of grout within the auger
' Fred Meyer 11-07400-02
29 April 1994 Page 6
during its withdrawal and appropriate steel reinforcement should be placed within each pile. A single
' reinforcing bar should extend the full length of the pile for uplift load transmittal.
' A completed augercast pile is installed entirely below the ground surface,and it may be difficult to determine
whether it has been installed properly. It is recommended that a representative from our office observe and
' monitor augercast pile installation on a full-time basis. In this way, by using experience and judgement, the
adequacy of each pile may be evaluated as it is installed. The procedures utilized by our representative
would include observation of the rate of auger penetration, speed of auger withdrawal, rate of grout injection
and a comparison of the actual grout take with the theoretical volume of material needed for each individual
pile. In order to complete this work it would be essential for the contractor to include with the grout pump
' a calibrated meter or stroke counter which indicates the volume of grout delivered to the pile.
' 4.1.2 Steel Pipe Piles
The following recommendations for vertical, uplift and lateral pile capacities are provided for the design of
a foundation system utilizing driven steel pipe piles. The piles should be driven to end-bearing support
within very dense soils present below the silt. Borings in the building area encountered the bearing soils
at depths of 15 to 30 feet below planned finished floor elevation. To estimate typical pile lengths, penetration
of 10 feet into very dense soils could be assumed for pipe piles, although variations should be expected.
If determination of pile length is critical, a program of pile test-driving may be appropriate.
' Piles should be driven to the design capacity based on an appropriate dynamic pile driving formula (such
as the ENR) and should be sized for anticipated compressive driving stresses. Pipe piling should be driven
close-ended, and should be predrilled through the fill soils above the silt in order to reduce downdrag and
hard driving conditions. We anticipate that an allowable vertical capacity of 40 tons can be obtained with
12-inch nominal diameter pipe piling, dependent on structural design requirements. This capacity assumes
limited downdrag loading on the pile shaft.
4.1.3 Lateral Pile Design
' With the expected embedment depths on the order of 25 to 40 feet, the ultimate resistance to an applied
lateral load would be governed by a combination of the strength characteristics of the pile and the soil.
Based on the use of a 12-inch diameter concrete filled steel pipe and a 12-inch diameter augercast pile, we
estimate that allowable lateral pile capacities of 7 and 5 tons per pile can be assumed, respectfully. A
limiting deflection of 0.5 inches at the ground surface has been assumed in these lateral load capacity
r
Fred Meyer 11-07400-02
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1
calculations. These recommended values are based on the assumption that all pile caps will be at or below
the ground surface and pile cap connections will be designed rigidly. An allowable passive resistance of
250 pcf can be assumed for pile caps and grade beams penetrating into structural fill, neglecting the first
foot of penetration below ground or slab surface. Higher lateral capacities can be obtained for increased
deflections. Uplift loads can be resisted by skin friction along the portion of the shaft penetrating the bearing
horizon. An allowable uplift resistance of 1 kip per square foot of shaft surface area can be used for design.
4.1.4 Piling Installation
' We recommend that pile spacing within groups or rows be no less than 3 pile widths center-to-center. Steel
piles should be driven with a diesel, air, or steam hammer having a rated energy of not less than 20,000 foot
' pounds. The actual pile capacity should be verified in the field based on an appropriate dynamic pile driving
formula. If close-end pipe piles are utilized, it is recommended to predrill through to the top of the silt
' deposit in order to limit downdrag loading. The recommended diameter of the predrilled hole is 2 inches
less than the actual diameter of the pipe pile. Pile driving may also densify the site soils, and the contractor
should be prepared for difficult driving conditions. If predrilling is accomplished, it should extend no deeper
than the top of the silt layer immediately underlying the fill soils. If hard driving conditions are encountered
above the minimum recommended pile depth, it may be necessary to fill the pipe with water, drive with a
' mandrel, or predrill through localized dense zones. Prior to ordering steel for production pile driving, a test
driving program is recommended to confirm pile capacity and anticipated pile penetration. With the test pile
rprogram, pile driving conditions (i.e., hammer, pile wall thickness and diameter, cushion, etc.) should
conform to production driving.
The installation of all piles should be observed by an experienced geotechnical engineer or engineering
geologist. Observation of pile handling, pile hammer operating characteristics, and pile penetration
resistance would make it possible to confirm the recommended penetration depth, monitor variations in
subsurface conditions and evaluate the pile capacity using appropriate dynamic pile driving criteria. We
' recommend that the vertical capacity of the driven piles be verified in the field based on dynamic pile-driving
criteria. Any such criteria should allow for variations in physical factors such as the pile hammer energy,
' size, type and length of piles, and modulus of elasticity of the pile materials. Appropriate criteria could be
developed based on a wave equation analysis or other dynamic drivability criteria. Once a pile section has
r been selected, recommendations for hammer energy can be provided. Locally dense zones within the fill
soils above the bearing horizon may present difficult driving conditions. The pile wall thickness should be
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' Fred Meyer 11-07400-02
29 April 1994 Page 8
selected to allow hard driving without damage to the pile casing. For pipe piles driven with predrilling, we
tentatively recommend a minimum wall thickness of '/4 inch.
' It is recommended that a minimum factor of safety of 2.0 be applied to ultimate capacity as determined by
the dynamic pile-driving criteria during initial driving. If a factor of safety of 2.0 is not achieved at the
' anticipated bearing depth during initial driving, a number of piles should be redriven for a short distance
following a waiting period. Dynamic pile capacity for the redriven piles should be evaluated using a
minimum factor of safety of 2.5. We recommend that pile groups be driven starting at the middle of the pile
' group working outwards. We recommend that jetting not be allowed except under the specific
recommendation for the geotechnical engineer at the time of construction. Jetting can significantly reduce
the allowable side friction available on the piles and lateral capacity.
Following driving, pipe piles should be checked for plumbness and to confirm that they have not been
damaged or bent by driving operations. They should then be filled with reinforcing steel and concrete. The
' piles should be free of water when the concrete is placed, or the concrete should be tremied up from the
bottom of the piles. A minimum distance of at least 15 feet should be maintained from piles which have
been freshly concreted when driving nearby piles. This minimum distance should be maintained until at least
i24 hours after pouring the concreted pile. Heave should be monitored with optical survey level on nearby
piles when driving adjacent piling. Piles should be redriven if heave exceeds 0.01 foot. Concrete placement
' should be deferred until the risk of heave is negligible, and it may be desirable to pour concrete in all piles
in a pile cap after completion of all pile driving operations.
4.2 Preload Fill Recommendations
Without mitigative pretreatment,the site soils encountered in our explorations would tend to consolidate and
settle excessively under newly placed fill, foundations, and heavily loaded floor slabs. As an option,
preloading may be considered to minimize post-construction settlement. Due to the close proximity of the
existing tenant 'B' building with the proposed Fred Meyer buildings, unacceptable differential settlements
of the tenant'B' building may result if preload is applied adjacent to this building. We therefore recommend
' that portions of the new building areas adjacent to tenant 'B' not be preloaded and instead be pile
supported. Preloading would involve the placement of a temporary load on the ground surface, usually in
' the form of imported fill materials. The temporary fill weight is used to equal or exceed future structural and
slab loads, so that much of the settlement will occur under the preload prior to construction of the
subsequent settlement-sensitive floor slabs and structural elements.
IFred Meyer 11-07400-02
29 April 1994 Page 9
The effectiveness of the preload depends not only on the intensity of the applied load, but also on the
amount of time that the load is allowed to remain in place. Assuming a unit weight of preload fill material
equal to at least 120 pounds per cubic foot,we recommend a preload fill height of 8 feet above finished floor
' elevation for the proposed Fred Meyer Store. We estimate that the required duration for such a preload will
be on the order of 8 weeks. We would be available to evaluate alternative preloading programs if the
construction schedule so dictates. The actual duration of preloading will, however, depend on settlement
rates and magnitudes monitored during this period. The fill height and preload duration estimates contained
herein are based on theoretical data. Actual preload durations may be significantly less than theoretical
' values owing to the discontinuous nature of the cohesive soils and the anisotropic drainage characteristics
of the alluvial site soils. For this reason, it is critical to monitor the preload using settlement plates and
optical survey methods.
It would be most practical and cost effective to perform all the site preparation activities prior to placement
of the preload fill. Our recommended construction sequence would be as follows:
1. Overexcavate existing fills or underlying native soils, where required, and replace with
structural fill compacted as recommended herein.
2. Place permanent grade fill, compacted as recommended herein.
3. Place preload fill above permanent grade fill.
4. Monitor preload settlement during preload period.
5. Remove preload upon recommendation of geotechnical engineer.
6. Fine grade and proofroll subgrade surface.
7. Construct footings and slab-on-grade floors.
' All fill which is to be permanent should be placed as structural fill. Temporary preload fill, however, may be
placed with nominal compactive effort by wheel or track rolling with the available construction equipment.
It would be desirable that the preload fill material, or at least a significant portion thereof, consist of relatively
clean sand or sand and gravel which could be utilized for subsequent grading activities. This would also
' enhance the preload fill placement and reduce weather dependency while conducting the work.
Furthermore, the material could be used for grading parking and driveway areas after completion of the
' preload. The top of the preload fill should extend laterally at least 5 feet outside of the building limits and
should be sloped down at an angle no steeper than 1.51-1:1 V(Horizontal:Vertical). Steeper side slopes would
be feasible if a suitable method of earth retention is implemented.
' Fred Meyer 11-07400-02
29 April 1994 Page 10
We estimate that the preload fill for the Fred Meyer Store could settle in excess of 4 inches. It is essential
' to monitor the progress of the preload fill settlement. Field time rate of settlement data will enable us to
refine our settlement estimates and establish actual requirements for preload duration. For this reason, we
' recommend the installation and monitoring of a series of settlement plate monuments. Plates should be
installed on approximately a 150-foot grid layout, with a minimum of 8 plates recommended for the Fred
Meyer building pad. Initial settlement plate readings should be obtained immediately after placement of the
plates and prior to placement of any structural or preload fills. Readings of the settlement plates should be
taken by standard differential optical leveling methods to the nearest 1/100th of a foot, and should be taken
' at regular intervals during the entire filling and preload period. RZA AGRA should be provided with a
location survey for the preload, indicating the crest location of the full depth preload fill and the total fill
thickness above existing grade at the corners and center of the preload fill immediately after fill placement.
' As previously discussed, the quality of preload fill material should be selected in consideration of potential
future uses and workability. If the owner elects to fill with moisture-sensitive soils, the owner should be
' made aware of the potential schedule problems if this work must be done during the rainy season. Similarly,
if the preload fill is moisture-sensitive, it could seriously impact project schedule if preload removal must
occur during periods of wet weather. Preload fills should be placed in uniform layers no greater than 18
inches in loose thickness and moderately compacted by construction equipment to allow equipment travel.
The surface should be fine graded, sealed, and crowned as necessary to promote runoff.
4.3 Shallow Foundations os
' The preloaded site would be well-suited for support of conventional shallow foundations. All footings should
be founded within the compacted structural fill which was placed above a stripped and properly prepared
' subgrade below the preload fill. Footings should not be founded on or within loose or disturbed native or
fill soil, or topsoil. Continuous or column footings founded within structural fill compacted to 90 percent
density(ASTM:D-1557) may utilize a maximum allowable bearing pressure of 2,000 pst. A one-third increase
1 of these bearing pressures may be used for short-term wind or seismic loading. Exterior footings should
extend at least 18 inches below adjacent grade for frost protection, while the interior footings should extend
' at least 12 inches below adjacent grade. We recommend that all continuous and isolated footings be at
least 12 and 24 inches in width, respectively. These recommendations consider that the footings will be
underlain by at least 2 feet of compacted structural fill.
LFred Meyer 11-07400-02
29 April 1994 Page 11
We estimate that the total settlement of foundation elements found within the prescribed bearing strata may
approach 3/4 inch. Differential settlement of foundations founded within the same soil type could approximate
one-half of the total settlements. If possible, we recommend that foundation elements be placed within the
same soil type to minimize the magnitude of possible differential settlement. Differential settlement could
approach the total settlement values if adjacent footings are founded on different bearing strata.
Under no circumstances should footings be cast atop loose or soft soil, slough, debris, or surfaces
containing standing water. Bearing soils should be undisturbed and soil conditions should be consistent
' with the recommendations contained within this report. We recommend that footing subgrades be assessed
by the geotechnical engineer, or his/her representative, prior to placement of a wearing surface or pouring
' concrete.
' Lightly loaded walls such as low rise building facades may be supported by conventional shallow spread
footings without preloading. Such footings may be designed with a maximum allowable bearing pressure
of 1,500 pounds per square foot including both dead and live loads. An increase of 1/3 may be used for
short term wind or seismic loadings. The base of exterior footings should extend at least 18 inches below
adjacent outside grade for frost protection. In any case, the footings should have a minimum width of at
' least 18 inches.
Prior to the installation of limited-use shallow spread footings without preloading, it would, however, be
necessary to overexcavate the existing soils to a depth of at least 2 feet below design footing elevation. The
base of the excavation should extend laterally outside of the footing line in all directions a horizontal distance
of at least 2 feet. The resulting excavation should be backfilled with a compacted structural fill. Compaction
' should be to at least 90 percent of the laboratory maximum density using ASTM:D-1557 as a standard.
Overexcavation and backfill recompaction should all be performed under the full time observation and
testing of a representative of our office. In this way the adequacy of the work may be evaluated as it is
performed and if questions arise they may be resolved promptly.
' 4.4 Floors
We understand that site grades will be raised approximately two feet prior to building construction. Without
site preloading,the loads imposed by this new fill may result in 1 to 2 inches of settlement. For this reason,
we recommend fills to raise grades be placed well in advance of floor casting to reduce post-construction
settlements to tolerable amounts. Based on laboratory testing of secured samples, we recommend that site
i
! Fred Meyer 11-07400-02
29 April 1994 Page 12
fill be placed at least 60 days prior to slab casting operations. In heavily loaded storage area (200 psf floor
' loads), we recommend that a 2-foot surcharge fill placed above the fills required to raise grade be provided
for 60 days prior to slab casting. The purpose of this limited preload is to promote uniform settlement
performance of all slab-on-grade areas. These recommendations are applicable if the pile foundation option
is selected, but are not applicable if the full building preload and spread footing option is utilized.
! Concrete slab-on-grade floors or structural floor systems may be utilized at this site. If slab-on-grade floors
are utilized, they should be cast atop a minimum 2-foot thick blanket of 90 percent density (ASTM:D-1557)
compacted structural fill with the surcharging recommendation presented above provided. Typically, we
recommend that the floor slab be protected from dampness with an impervious moisture barrier and a 4-inch
thick capillary break. As an alternative to a moisture barrier, a 1-foot thick capillary break and no vapor
barrier may be used provided that the slab elevation is higher than surrounding grade, the building has a
footing drain system, and the majority of the building exterior area is hard surfaced. Capillary break should
consist of clean, free draining pea gravel, washed rock, or crushed rock. This drainage blanket should
contain no more than 3 percent by weight passing the No. 200 sieve, when measured on the minus No. 4
sieve fraction. Another alternative to a moisture barrier is an epoxy based additive which reportedly seals
concrete from moisture. We feel that this additive is an acceptable alternative to a moisture barrier.
' However, cracks may allow some moisture infiltration regardless of treatment.
4.5 Backfilled Walls
All backfill placed behind walls or around foundations should be placed per our recommendations for
structural fill, drainage considerations, and as described in this section of this report. The following
recommended earth pressures, presented as equivalent fluid weights, are based on the assumption of a
' uniform level granular backfill and no buildup of hydrostatic pressure behind the wall. To minimize lateral
earth pressures and prevent the buildup of hydrostatic pressures, the wall backfill should consist of a free
draining granular material with drainage provisions as discussed in the subsequent drainage consideration
' section of this report.
' If the backfilled walls are structurally restrained from lateral movement at the top, we recommend that they
be designed for an equivalent fluid weight of 55 pounds per cubic foot (pcf). If the tops of the walls are free
' to move laterally in an amount equal to at least 0.1 percent of the wall height during and after placement
of backfill soils, they may be designed for an equivalent fluid weight of 35 pcf.
Fred Meyer 11-07400-02
29 April 1994 Page 13
Surcharges due to sloping ground,adjacent footings,vehicles, construction equipment, etc., must be added
' to these values. The above equivalent fluid pressures assume that the backfill is compacted to 90 percent
of the laboratory maximum density in accordance with ASTM:D-1557. Additional compaction adjacent to
the wall will increase lateral earth pressures while a lesser degree of compaction could permit post-
construction settlements.
It should be noted that some minor settlement of wall backfill may occur with time. Typically this is not a
problem except where settlement sensitive surfaces or structures are founded in the backfill. Special
considerations may be necessary where utilities penetrate through the backfill and into the wall since even
minor soil settlements can cause damage to piping.
4.6 Drainage Considerations
At the time of our geotechnical explorations, the bulk of the development area was surfaced with an
asphaltic concrete pavement. As a result, rainfall and runoff is directed to an existing storm drainage
system. Our test borings encountered groundwater at depths on the order of 6 feet or more below the
existing ground surface. However, the site is situated adjacent to the former channel of the Black River,the
historic outlet to Lake Washington. Therefore, under worse case conditions, groundwater levels could rise
1 to near the ground surface, in our opinion.
In order to minimize the risk of ponding or standing water adjacent to the buildings, we recommend that
the ground around the structures be sloped downward away from the buildings to an appropriate storm
1 drainage system. Additionally, we recommend that a perforated pipe footing drain be installed around each
building. These footing drains should include a perforated pipe embedded in a sand-free pea gravel filled
trench. The footing drain system should be set below the level of the bottom of adjacent floor slabs. The
footing drain network should be permitted to discharge downslope by gravity into the storm drain network
or into a pumped sump. Roof and surface runoff should not discharge into the footing drain network.
' Instead, a separate tight line drainage system or splash blocks should be utilized. Similar to the footing
drain system, all backfilled walls should be provided with a perforated pipe drain capable of discharging
' downslope by gravity.
' 4.7 Site Preparation and Grading
Under some circumstances, the initial step in site preparation would involve the removal of any surficial
' material such as vegetation, topsoil, walkways or paving. At this site, however, it may be appropriate to
Fred Meyer 11-07400-02
29 April 1994 Page 14
retain as much of the existing asphalt in place in the addition areas as possible, for as long a time as is
practical. In this way,the contractor would be able to operate across a relatively stable and durable surface
during foundation installation efforts. In those areas where a structural floor slab is utilized which does not
' depend upon the underlying soil for support, it will be possible to leave the existing asphalt surfacing in
place. In those areas where a non-structural floor system is installed and beneath concrete walkways it
' would be appropriate to remove the asphalt surfacing. Beneath the new surfacing, the ground to a depth
of at least 2 feet should be overexcavated and recompacted so that a density of at least 95 percent of the
laboratory maximum (ASTM:D-1557) is achieved.
Several monitoring wells are present at the site from previous explorations. The Washington Administrative
' Code (WAC 173-160-560) describes requirements for the abandonment of monitoring wells (resource
protection wells). Provided that the wells were constructed in accordance with current regulations,they may
' be abandoned by filling the casing from the bottom to the surface with grout or bentonite clay. The
abandonment must be documented in accordance with Washington Department of Ecology recordkeeping
' requirements. We recommend that the wells be abandoned prior to construction at the site.
Backfill around foundation elements and behind walls, as well as fill in general, should be compacted to at
least 90 percent of the laboratory maximum density based on ASTM:D-1557, the modified Proctor method.
Similarly utility trench backfill should be compacted to at least 90 percent density, as well as be compacted
' and bedded in accordance with project plans and specifications and current local codes and standards.
However, in the case of underground utility trench backfill beneath the parking lot, the uppermost 2 feet of
soil should be compacted to at least 95 percent of the same density (ASTM:D-1557).
' Structural fill should be placed in level lifts not exceeding 8 inches in loose thickness, when compacted with
heavy equipment. Where small or hand-operated equipment must be used due to space limitations or
proximity to structures, lifts should be reduced to 4 inches. Individual lifts should be compacted to the
' above recommended density. A representative from our firm should be present during fill placement and
compaction to observe the work and perform a representative number of in-place density tests. In this way
' the adequacy of the earthwork may be evaluated as grading progresses.
The suitability of soils for structural fill use depends primarily on the gradation and moisture content of the
soil when it is placed. As the amount of fines (that portion passing the U.S. No. 200 sieve) increases, soils
' become increasingly sensitive to small changes in moisture content and adequate compaction becomes
Fred Meyer 11-07400-02
29 April 1994 Page 15
more difficult to achieve. Soil containing more than about 5 percent by weight passing the U.S. No. 200
Sieve cannot be consistently compacted to a dense non-yielding condition when the moisture content is
more than a few percent wet of optimum.
' The available soils on site will be difficult or impossible to use as structural fill except during the summer
months when drying is possible. Even then, delays in grading are common due to inclement weather. If
rain occurs while the subgrade is exposed or during placement of on-site material (or any soil with over 5
percent fines), the material should be allowed to dry prior to additional filling. It may be necessary to scarify
the upper layer, allow it to dry and recompact prior to additional filling. Overexcavation or removal of wet
soils may be necessary if it is not practical to dry and compact them. In order to expedite grading, it may
' be appropriate to utilize a clean, imported, granular soil for fill. Soils to be used for structural fill should be
free of organics and other deleterious material. The soil fraction passing the U.S. No. 200 Sieve should be
' limited to 5 percent or less by weight when measured on the minus No. 4 Sieve fraction, if a non-moisture
sensitive material is required. In any case, soil used for structural fill should have maximum particle size on
' the order of 6 inches.
4.8 Pavement
' Pavement design must be recognized as compromise between high initial cost with little maintenance as
one alternative and low initial cost coupled with the need for periodic repairs as the opposite option. As a
result the owner will need to take part in the development of the appropriate pavement section. Critical
features which govern the durability of any surfacing include stability of the subgrade; the presence or
absence of moisture,free water and organics;the fines content of the subgrade soils;the traffic volume;and
the frequency of use by heavy vehicles. At this site we have based our designs on the following
assumptions:
The existing asphalt pavement will be retained wherever possible;
1 Entry drives and truck delivery lanes will be provided with a similar pavement depth;
A 20 year pavement design life, based on traffic indices of 4 and 6, is required.
Based on the above criteria, in those areas where the existing3-inch asphaltic surfacing is relative) intact
P 9 Y
we recommend that any minor cracks and defects be sealed prior to the installation of a 1Ih-inch asphaltic
concrete overlay. In those areas where the existing asphalt is relatively intact except for the existence of
such identifiable localized features as linear fractures or joints between strips of asphalt or where minor
' Fred Meyer 11-07400-02
29 April 1994 Page 16
cracking has developed, fractures should be filled and the area covered by Petromat or Petrotac strips prior
to the installation of a 1,h-inch asphaltic concrete overlay.
' In those areas where more severe pavement distress has developed or the existing surfacing is damaged
by alligator cracking, it would be appropriate to remove the defective surfacing and underlying weak
' subgrade soils. The resulting excavation should be backfilled with a clean, coarse granular backfill
compacted to at least 95 percent of the laboratory maximum density (ASTM:D-1557).
In those areas where an entirely new surfacing will be installed, the existing asphaltic concrete surfacing
should all be removed along with the underlying soil to provide a firm subgrade. The resulting excavation
should be backfilled with 95 percent density compacted structural fill (ASTM:D-1557). With this configuration
we suggest that general parking areas be provided with a pavement which includes 3 inches of asphaltic
' concrete atop 4 inches of crushed rock base course. Major driveways and truck access and delivery lanes
should be provided with pavement section of 4 inches of asphaltic concrete atop 6 inches of crushed rock
' base course.
We understand that some existing asphalt will be crushed and reused in parking areas. Based on past
experience, crushing typically results in a 2-inch minus aggregate which would be suitable for subbase fill
in parking areas but not a substitute for crushed rock base course. If this material is to be used in place
' of asphalt treated base, hot rebatching will be necessary.
' 4.9 Utility Considerations
Utility trench backfill should be compacted to at least 90 percent density, as well as be compacted and
bedded in accordance with project plans, specifications and current local codes and standards. However,
in the case of underground utility trench backfill beneath the parking lot, the upper 2 feet of soil should be
compacted to at least 95 percent of the same density (ASTM:D-1557).
Adequate dewatering of utility trenches will be necessary during utility installation. Based on our
' explorations, we expect groundwater to be encountered between 7 and 10.5 feet below the existing ground
surface. However, it should be noted that groundwater levels may fluctuate due to variations in rainfall, river
level, irrigation or other land uses. At shallow levels below the groundwater table adequate dewatering may
be accomplished utilizing portable pumps. At deeper levels higher groundwater inflow rates are likely and
other dewatering methods may be necessary, such as well points or pumping wells. Ultimately, dewatering
Fred Meyer 11-07400-02
29 April 1994 Page 17
is a contractor design issue and should be considered the responsibility of the contractor. The contractor
' should be responsible for design, operation, and maintenance of a dewatering system which is operational
until subsurface utility work is completed over a given area requiring dewatering. The groundwater levels
' should be maintained at least 2 feet below the trench bottom.
' We understand that water main construction is planned in the area of a steep slope in the northwest part
of the site from Sunset Boulevard West to Hardie Street. Based on our observations, the slope appears to
be composed of fill soils placed at the time of construction of Sunset Boulevard. Although loose on the
surface, the slope appears to be relatively stable at this time. We expect that water main construction will
be possible at shallow depths of 3 to 4 feet below existing slope surface. Adequate compaction of backfill
soils will be necessary to prevent future erosion or instability of the slope. The condition of the slope soils
should be observed by a representative of our firm at the time of water main installation to verify that the
' conditions are consistent with the above recommendations. We recommend that at least two sections of
sand filled burlap or polyethylene bag barriers be constructed within that portion of the trench within the
' hillslope area. Each sand bag barrier should be a minimum of 6 bags in width.
5.0 CLOSURE
The conclusions and recommendations presented in this report are based on the explorations completed
for this study. The number, location and depth of the explorations were completed within the site and the
proposal constraints to yield the information needed to formulate our recommendations. The integrity of
the foundations depend on proper site preparation and construction procedures. Because designs are
' currently in a relatively preliminary status we are available for any necessary plan reviews, consultation with
the design team and any needed subsequent observation and testing.
r
rFred Meyer 11-07400-02
29 April 1994 Page 18
r
We appreciate having the opportunity to assist you on this project. If you have any questions please do not
rhesitate to call.
rRespectfully submitted,
rRZA AGRA, Inc.
r
Mark A. Wicklund
r Staff Engineer
ME
WAa,��I y
r c �
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Kurt D. Merriman, P.E. "AO p 23 0 � ww
r Associate �c� GIs ti$
sslONAL���
rMAW/KDM/lad EXPIRES 11 /20
r
r
r
r
1
r
r
r
LEGEND
B-21
BORING NUMBER AND LOCATION (CURRENT STUDY�XIMATE
' RAINIER AVENUE SOUTH 13-19
(p BORING NUMBER AND APPR
TON (PREVIOUS STUDOXIMATE
LOCATION
B-4 B-15
' • AND
MONI ORIBRING NGBER WELLS INSTALLED) PREVOI0US N
CP-3 STUDY)
DTCHONE
ROBE
BER AND
8-11 EXISTING RETAIL (TYP.) �` • " AP ROXIMATELOCATIONn(PREVIOUS STUDY)
•
B-3
B-7
f- •
3 PARKING (TYP.)
cr
w
J J
D B-20
m y m —It FUTURE TENANT "C"
B-21
19
CP-3 BO
w
N
N ` C• 2 '
� 1
FRED MEYER B-17�
1 • B-1 �
-10 B-15 C®1 j
1 B-5
O
B-14 B-16 --
' B-13
B-2
B_g HARDIE STREET
RZA-AGRA W o 1 �4 -2 PROPOSEDRENTON CENTER
' ENGINEERING&ENVIRONMENTAL SERVICES DESIGN MAW RENTON, WASHINGTON
11335 N.E. 122nd Way DRAWN DMW
Suite 100' DATE APR 14 SITE & EXPLORATION PLAN Kirk/and, WasAilVton
98034-"1B SCALE 1"=1 '
FIGURE 1
Appendix A
' APPENDIX A
SUBSURFACE EXPLORATION LOGS
PROJECT: Renton Fred Meyer W.O. 17-07400-07 BORING NO. B-20
SOIL DESCRIPTION w z STANDARD PENETRATION RESISTANCE
Page I
of 2
Ak Blows per foot
Approximate ground surface elevation: 23 feet
0 a 0 10 20 30 40 50TESTING
3.5'Asr)hait over 6'sandv crushed rock
Loose,moist,grayish brown,fine to medium -------- ............... ................................
.............
SAND with some silt(Fill)
------------------------------------------ ...........t ............... ......................
...... ................................. ............................................................
S-7
--------------------......................................... ...........
5
Loose,moist,grayish brown to gray,fine to
medium SAND with some silt Interbedded with
------ ......... .............................---------- .............................
soft,wet,gray,sandy SILT with trace organics
-------------................... ............................
S-2
----------------.............................
Becomes saturated
H SB-
10 7
ATD
-
.......... ............
........ .........
... .....................
------------------------------------------ ---------..................
dilatant S-3
Dense to very dense,saturated,gray,fine to .................. ......................... ...............
coarse SAND with trace to some silt and some
- 15 gravel interbeds
4
dilatantS- ------- ..................-----------------..........
----------------............................
....
S-5
- 20 7 foot of heave—
S-6 ..........------- ...... >
Becomes very dense and gravelly
----------------------............................. ------- ............
----------------------......... -----------------
S-7
5
............ .......... .. ..........
25
' S-8 ..... 57
.....
.......... ....... ............
S-9 68. L
....................... ............................... ...............
(continued)
30 - 0 10 20 30 40 50
LEGEND MOISTURE CONTENT
2-inch OD split-spoon sample H 3-inch OD Shelby sampler Plastic limit Natural Liquid limit
RZA AGRA, Inc
Engineering&Environmental Services
' Groundwater level
AID at time of drilling X Sample not recovered 11335 NE 122nd Way,Suite 100
Kirkland,Washington 98034-6918
Drilling started: 28 March 1994 Drilling completed: 28 March 7 994 Logged by: MAW
PROJECT: Renton Fred Meyer w.0. 7 7-07400-0 7 BORING NO. B-20
x W W � 2 Page 2
SOIL DESCRIPTION STANDARD PENETRATION RESISTANCE
of 2
ABlows per foot
O V) C6
Approximate ground surface elevation: 23 feet 0 9 0 10 20 30 40 5oTESTING
30 -1 q
Very dense,saturated,gray,gravelly,fine to
coarse SAND with some gravel interbeds ...........
................ --------------.............---------
.. ...............
2.5 feet of heave ---------------- ..........
5-70 F50,K�'A k
............ ................ ............................
35 -
.......... -------
.......... ................................... ........
...................... .................
..........
............................. ....... ---
- 40 -
..................... ----------- ........................................
............. --.................... ....... ............ ..........
..................
TS-11
Boring terminated at approximately
- 45 -
44 feet
..................... ......................................
-----------
7...................................... ---------------...................................
.................................
..........
50 -
.............
............................... .........- ..........
....................
...........----------
................................ ............... ..............................
55 -
.......... ------------7 ................
....................... ......
................... .................... ..........................
60 10 20 30 40 5o
LEGEND MOISTURE CONTENT
2-inch OD split-spoon sample 3-inch OD Shelby sampler Plastic limit Natural Liquid limit
RZA AGRA, Inc
Engineering&Environmental Services
Groundwater level
ATD at time of drilling X Sample I not recovered 11335 NE 122nd Way,Suite 100
Kirkland,Washington 98034-6918
Drilling started: 28 March 7994 Drilling completed: 28 March 7994 Logged by: MAW
PROJECT: Renton Fred Meyer W.O. 11-07400-0 7 BORING NO. B-2 7
H SOIL DESCRIPTION a w 2 x STANDARD PENETRATION RESISTANCE Pagel
m of 2
U Q . Blows per foot
a Approximate ground surface elevation: 23 feet rA C6 z U 3 0 10 20 30 40 soTESTING
' 0 2'Asphalt over 6'sandy crushed rock over 6'
moist,brown,SAND with some silt(Fill)
-------------------------------------------
_................_._..,...___........ ._.__.................
...........---------
' Loose,moist to wet,brown to gray,silty,fine _ ....
SAND Interbedded with gray,sandy SILT with S-7
some organic silt and peat --... ............ ..._.._._.. --.._. --...... -._..................
' 5
S-2 Bb ounj
..... ...._....._._........._.......... ----- -----
ATD1..._.__......__..i......... ...._._«................................ .... ....
........ .. - -
' 10 SB-
.........._._._.......... ..............._............
' S-3
SB-
--------------- ------------------ '....._...-.... - ......
Dense,saturated,gray,fine to medium SAND
15 with trace silt interbedded with gravelly,fine to
coarse SAND and sandy GRAVEL S-4
.....
... _.
1 S-5
20
S-6 - __.........................._.__..._._.._.._......._..
__------
----------------__....._..........__........_..._....._...
' Becomes very dense S-7 50 6'
...
..............
.................
25 -
' S-8 50 6
.......... ............_...._..._.._--- --------._._.....
' 4.5 feet of heave
....._.............._............_-
S-9 50 6'
' 30 (continued) o 10 20 30 40 so
LEGEND MOISTURE CONTENT
' ligrrid limit
�/,
I 2-inch OD split-spoon sample El Plastic limit Natural 3-inch OD Shelby sampler A AGRA, Iric
' Engineering&Environmental Services
Groundwater level
ATo at time of drilling Sample not recovered 11335 NE 122nd Way,Spite 100
Kiridand,Washington 98034-6918
' Drilling started: 28 March 1994 Drilling completed: 28 March 1994 Logged by: MAW
PROJECT: Renton Fred Meyer w.O. 11-07400-0 7 BORING NO. B-2 7
;r- W t W 2W STANDARDPENETRATION RESISTANCE Page
SOIL DESCRIPTION � W
� R A Blows per foot of 2
Ga Approximate ground surface elevation: 23 feet < � 1
30 - V) z 0 10 20 30 40 50TESTING
Very dense,saturated,gray,gravelly,fine to
coarse SAND ............................................
.........................................................................
....................
f�50,
70�
35
Boring terminated at approximately
-
34 feet
----------- ..........--------
........... -------------------........... .....................
............... ........------- .........---------............................
.............. ...........................-------...............................
- 40 -
........... ...... .......... ............. ...................
...................
........... ............. .........
- 45 -
........... --------------------------------------------------------------
....................................7
......... .......... .................... .................... ..........
50 -
.......... ................ .........................
------------ ...................... .............................
.............. . ..........................
- ---------
. ................ .................... ....................
55 -
............
...................
.....................................
60 0 10 20 30 40 50
LEGEND MOISTURE CONTENT
i 0 A
Plastic Emit Natural Liquid limit
2-inch OD split-spoon sample Ll 3-inch OD Shelby sampler
RZA AGRA, Inc
Engineering&Environmental Services
'W Groundwater level
AID at time of drilling X Sample not recovered 11335 NE 122nd Way,Suite 100
Kirkland,Washington 98034-6918
Drilling started: 28 March 1994 Drilling completed: 28 March 1994 Logged by: MAW
Appendix B
r
' APPENDIX B
LABORATORY TESTING PROCEDURES AND RESULTS
' APPENDIX B
11-07400-02
' LABORATORY TESTING PROCEDURES
A series of laboratory tests were performed 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 watertight containers and
transported to our laboratory where the field classifications were verified or modified as required. Visual
classification was generally done in accordance with the Unified Soil Classification system. Visual soil
t classification includes evaluation of color, relative moisture content, soil type based on 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. The results of the tests are shown on the
consolidation and Atterberg limit plots in this appendix.
' 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 plastic index
' (liquid limit minus plastic limit) is related to the liquid limit.
' Consolidation Test
A one-dimensional consolidation test was performed in general accordance with ASTM:D-2435 on a selected
sample of the site soils to provide data for developing settlement estimates. The undisturbed soil sample
' was carefully trimmed and fit into a rigid ring. Porous stones were placed on both the top and bottom of
the sample to allow drainage. Vertical loads were then applied to the sample incrementally in such a way
that the sample was allowed to consolidate under each load increment. The rebound of the sample during
unloading was also measured. The results of the consolidation test are presented in this appendix as a plot
of percent consolidation (strain) versus applied load (stress).
r
CONSOLIDATION ASTM: D2435
1/8 1/4 1/2 1 2 4 8 16 32 64
' 0.0
' 2.0
4.0
6.0
O
a 8.0
' c
c
N 10.0
' C
O
12.0
' GL—
Q
14.0
' 16.0
18.0
' 20.0
0.1 1.0 Stress in Tons/Feee 10.0 100.0
' 3.00
T 2.50
2.00
1.50
1. 0
U 0.50
0.00
' 0.1 1.0 10.0 100.0
Project: Renton Fred Meyer RZA AGRA, Inc.
Work Order. 11-7400-02 Engineering & Environmental Service
Date: 4-6-94 Depth
Exploration: B-21 Sample: SB-2 11335 N.E. 122nd Way
Moisture: 43% Density: 92pcf Suite 100
USCS: Grey Silt: ML Krkland, Washington 98034-6918
PLASTICITY CHART ASTM: D4318
70
60
01
X 50 "u.LINE 'A'LI
0 •
Z CH or OH
U 40
F-
d 30
CL or o MH or 0
20
10
CL-ML O ML or OL
0
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
LIQUID LIMIT
Symbol Sample Type Sample Depth Moisture Liquid Limit Plastic Limit Plastic Index Description
O B-21 S&2 43% 39 32 7 ML
0
0
I �
® B-Boring Tp-Testpit Ha-Hand Auger Gb-Grab Bag X-Other
7 Project: Renton Fred Meyer RZ AAGRA, Inc.
Work Order: 11-7400-2 , Engineering & Environmental Services
Date: 4-13-94 11335 N.E. 122nd Way
Suite 100
l irldand,Washington 98034-6918