HomeMy WebLinkAboutSWP272250 + ' Earth Consultants Inc.
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July 13, 1992 PR-5576
Opus Development
5540 Lake Washington Boulevard Northeast
Suite 110
Kirkland, Washington 09033
Attention: Mr. Doug Klappenbach
Subject: Consultation
Puzet Western Business Park
East Valley highway & Southwest 27th Streit
Renton, Washington
References: GeoEngineers, Inc.
Geotechnical Investigation
File No. 186-08
Dated February 22, 1982
GeoEngineers, Inc.
Geotechnical Engineering Services
File No. 0340-014-RO1
Dated March 27, 1992
Dear Mr. Klappenbach:
As requested, we have reviewed the referenced reports for the subject site. The purpose or this letter
is to provide our initial opinions on the recommendations presented in the referenced reports. We are
in the process of submitting a proposal to perform an additional geotechnical engineering study for the
subject site.
Based on our review of the referenced reports, we are in agreement with the referenced reports'
recommendations with the following comments:
• The referenced report recommends that footings be supporter) on at least 24 inches of
compacted structural fill. However, the existing fill on the site may be suitable for use
as structural fill if recompacted. Overexcavation (except in debris areas) may not be
necessary.
1805.136th Place N.E.,Suite 101, Bellevue,Washington 98005
y E. 26th Street,Suite 101,Tacoma,Washington 98421.9998
Bellevue(206)6433780 Seattle(206)464.1584 FAX(206)746-0860 Tacoma(206)272.6608
Opus Development PR-5576
July 13, 1992 Pave 2
• The referenced GeoEngineers' report dated March 27, 1992, recommends four to six feet
of surcharge for area where slab loads are 250 psf and 500 psf, respectively. In our
opinion, three feet of surcharge for slab loads of 250 psf and five feet of surcharge for
slab loads of 500 psf should be sufficient.
• In our opinion, the existing fill soils should be suitable for pavement support, except in
soft or unstable soil areas. Overexcavation may be required in areas where debris is or
soft or unstable conditions are encountered.
• In our opinion, the topsoil and root mat—Qf the existing vegetation can be left in place in
fill areas provided a .m ni_n. m_of two feet and _one foot of sr^-,-.rural fill underiie
foundations and�pavemenf�; resp_ectively. In this case, the vegetation must oe cut, with
asses ieft in place in area to receive fill. Vegetation other than grasses orusti,
must be removed.
The above opinions are based soieiy on our review of the referenced reports. Additiorai subsurface
information and engineering analysis, as outlined in the above mentioned proposal, will be recuired in
areas that have not been e=iored or require further exploration.
We hope this letter meets your current needs. If you have any questions, please call.
Very truly yours,
E.-kRTH CONSULTANTS, INC.
Kyle R. Campbell, P.E.
Project NImia;er
Robert S. Levinson, P.E.
President
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Earth Consultants, Inc.
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Consulting Geotechnical
Engineers and Geologists
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Report
Geotechnical Engineering Services
Proposed Puget
Renton, • •
For
Puget Western, Inc.
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Geo Engineers
March 27, 1992 Geotechnical,
Geoenvironmental and
Geologic Services
Puget Western, Inc.
19515 North Creek Parkway, Suite 310
Bothell, Washington 98011
Attention: Mr. Bob Farrell
We are pleased to submit three copies of our "Report, Geotechnical Engineering Services,
Proposed Puget Western Business Park, Renton, Washington."
The scope of our services for this study is described in our proposal dated January 14,
1992. Authorization to proceed with the services was provided by Mr. Farrell on January 13
after discussing the proposed scope of our services. Portions of our findings and preliminary
recommendations were discussed with Mr. Farrell and Mr. Bob Cunningham of Opus
Corporation as they were developed.
It has been our pleasure to work with you on this project. If you have any questions
regarding the contents of our report or if we may be of further service, please call.
Yours very truly,
GeoE eers, Inc.
�
el.-,
J ca c Tuttle
Principal
ncr:;m
DOC ID: 0340014.R
File No. 0340-014-RO1
'I
GeoEnoneers,Inc.
8410 154th Avenue N.E.
Redmond,WA 98052
Telephone(206)861-6000
Fax(206)861-6050
Printed on recycled paper.
CONTENTS
Paste No.
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
T
t SITE CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
SURFACE CONDITIONS 2
SUBSURFACE CONDITIONS 2
GROUND WATER CONDITIONS 3
CONCLUSIONS AND RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
GENERAL 3
SITE PREPARATION, PRELOADING AND EARTHWORK 4
Site Preparation 4
Preloading 5
General. 5
Preload and Surcharge Fill. 5
Settlement Monitoring. 6
Structural Fill 6
FOUNDATION SUPPORT 7
LATERAL RESISTANCE 8
FLOOR SLAB SUPPORT 8
PAVEMENTS 8
DRAINAGE CONSIDERATIONS 9
LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
FIGURES Fioure No.
VICINITY MAP 1
SITE PLAN - NORTH 2
SITE PLAN - SOUTH 3
SETTLEMENT PLATE DETAIL 4
i
G e o E n g i n e e r s 1 File No.0340-014-RO1/0392
APPENDICES Paae No.
Appendix A - FIELD EXPLORATIONS AND LABORATORY TESTING A-1
FIELD EXPLORATIONS A-1
LABORATORY TESTING A-1
APPENDIX A FIGURES Fissure No.
{ Soil Classification System A-1
11 Key to Boring Log Symbols A-2
Log of Boring A-3...A-5
Log of Test Pit A-6...A-9
Summary of Moisture Content Data A-10
Consolidation Test Results A-11
Atterberg Limits Test Results A-12
I
G e o E n g i n e e r s H File No.0340-014R01/0392
REPORT
GEOTECHNICAL ENGINEERING SERVICES
PROPOSED PUGET WESTERN BUSINESS PARK
RENTON, WASHINGTON
FOR
t PUGET WESTERN, INC.
INTRODUCTION
This report presents the results of our geotechnical engineering services for the proposed
Puget Western Business Park to be located in Renton, Washington. The location of the site is
shown on the Vicinity Map, Figure 1.
We have completed two previous studies on the site for Puget Sound Power and Light
Company. The details of these studies are presented in our "Phase I Report, Preliminary
Geotechnical Engineering Services, Proposed Store Warehouse" dated November 9, 1981 and
"Report of Geotechnical Investigation,Planned General Stores Facility"dated February 22, 1982.
Our November 1981 study included excavation of test pits across the entire site. Additional test
pits and five borings were completed in the southwest portion of the property as part of our
February 1982 study.
We understand that Buildings 1 through 3, to be located in the east portion of the property,
are to be constructed during the initial phase of development of the property. Four other
buildings (4 through 7) will be constructed subsequently. The proposed buildings will be build-
to-suit and are expected to contain both warehouse and office space. The buildings will have on-
grade concrete floor slabs and involve concrete tilt-up panel construction. We further understand
that the finished floor will be at about Elevation 21 in Buildings 1 through 5, and at about
Elevation 19 in Buildings 6 and 7. The pavement surface will be at about Elevation 17 near
Buildings 1 through 5, and about Elevation 16 near Buildings 6 and 7.
We discussed the building loads with Mr. Bob Farrell and Mr. Bob Cunningham of Opus
Corporation. The planned use of the buildings is not known at this time. We have, therefore,
estimated the building wall and column loads based on typical construction of this type in the
area. We estimate that the wall loads will be in the range of 2,000 to 3,000 plf (pounds per
lineal foot) and the column loads will be between 60 and 70 kips. We anticipate the floor slab
loads to be between 250 and 500 psf(pounds per square foot).
GeoEngineers is concurrently completing geoenvironmental studies on the site. The results
of the geoenvironmental study will be provided in a subsequent report.
SCOPE
The purpose of our services is to explore subsurface soil and ground water conditions in
the area of Buildings 1, 2 and 3 as a basis for establishing geotechnical recommendations and
G e o E n g i n e e r s 1 File No.0340-014-R01/0392
design criteria for the proposed development. Our specific scope of services includes the
following:
1. Excavate seven backhoe test pits to depths of 10 to 12 feet across the eastern portion of the
site to evaluate subsurface soil and ground water conditions.
2. Drill 3 borings in the eastern portion of the property to evaluate subsurface conditions. The
borings were drilled to depths ranging from 44 to 63 feet. Monitor wells were installed in
two of the borings to permit subsequent ground water monitoring and sampling.
3. Evaluate pertinent physical and engineering characteristics of the site soils based on
laboratory tests performed. on samples obtained from the borings and test pits. The data
obtained supplements data from our previous studies. Laboratory tests include moisture and
density determinations, consolidation tests and Atterberg limits determinations.
4. Provide site preparation and earthwork recommendations including recommendations for
a preload program to reduce postconstruction settlements in the building areas.
5. Develop foundation design recommendations including allowable soil bearing pressures and
settlement estimates for spread footings for the planned type of construction.
6. Provide recommendations for slab-on-grade construction.
7. Provide pavement design recommendations for both parking and roadway areas.
8. Prepare a written report presenting our conclusions, recommendations and supporting data.
SITE CONDITIONS
SURFACE CONDITIONS
The proposed Puget Western Business Park is located on a 34-acre site which is bounded
by East Valley Highway on the east, Lind Avenue Southwest on the west, Southwest 23rd Street
on the north and Southwest 27th Street on the south.
The site includes a low lying area in the north and west and up to 10 feet of debris fill over
much of the remainder of the site. The low lying area has been classified as a wetland, along
with several smaller areas which are located across portions of the debris fill. Scattered
deciduous trees are located along the west and north portions of the site. The low lying wet area
is vegetated with grasses and scattered blackberry thickets. The debris fill is vegetated with a
y- mixture of grasses, Scotch broom, blackberries and 15- to 20-foot-high bushes.
SUBSURFACE CONDITIONS
Subsurface soil and ground water conditions were explored by excavating seven test pits
and drilling three test borings in the previously filled east portion of the site. The locations of
the test pits and borings are shown on the Site Plans on Figures 2 and 3. A description of the
field exploration and laboratory testing procedures, logs of the borings and results of laboratory
tests are presented in the appendix.
The subsurface soil and ground water conditions encountered are generally consistent with
the results of our previous studies. The shallow fill soils encountered in our explorations consist
G e o E n g i n e e r s 2 File No.0340-014R01/0392
of 6 to 12 inches of loose rootmass and silty sand with occasional gravel, concrete debris and
wood fragments. These soils were very wet and equipment mobility was extremely limited due
to poor traction. The underlying fill generally consists of loose to medium dense silty sand with
gravel, concrete debris, brick fragments, scattered asphalt pieces and organic matter. The fill
was encountered in both the test pits and borings and extended to depths of about 8 to 12 feet
! where it overlies a layer of highly compressible peat, organic silt and silt. The test pits generally
extended to the surface of this compressible layer, but it was encountered to depths of 14 to
20 feet in the three borings. Boring B-1 encountered loose to medium dense, black to gray silty
fine sand and sand with silt below the compressible layer, from a depth of 17 feet to about
55 feet. Dense sand with gravel and sand with silt was encountered below this layer and
extended to the bottom of the boring at a depth of 63 feet.
Medium dense silty sand, sand with silt and sand was encountered below the compressible
layer in boring B-2 from a depth of approximately 20 feet to the bottom of the boring at a depth
of 44 feet. Boring B-3 encountered loose to medium dense silty sand below the compressible
layer from a depth of about 18 to 23 feet. Loose to medium dense silty sand with lenses of soft
to medium stiff silt was encountered from a depth of 23 feet to about 31 feet. Medium dense
silty sand was encountered below this layer and extended to the bottom of the boring at a depth
of 49 feet.
GROUND WATER CONDITIONS
Perched ground water was encountered on top of the fill in all the explorations within the
upper layer of rootmass and silty sand. Ground water was also encountered during drilling at
depths of 7.5 feet and 8.0 feet in borings B-1 and B-2, respectively, and at the ground surface
in boring B-3.
CONCLUSIONS AND RECOMMENDATIONS
GENERAL
We conclude that the proposed structures can be satisfactorily supported on conventional
shallow foundations and the floor supported as a slab-on-grade provided a preload and surcharge
_ program is implemented to preinduce much of the settlement which will otherwise occur under
structural and floor loads. Consolidation of the compressible peat and organic silt encountered
at the site under the weight of new fill and building loads will result in some settlement of the
structures. We present recommendations in the following subsections for site preparation and
earthwork and a preload program to develop satisfactory structural support and to reduce
postconstruction settlements to generally acceptable limits for the types or structures planned.
We further recommend the use of a surcharge fill pad within the proposed building areas to speed
the rate of settlement during the preloading period. Construction of footings and slabs should
commence only after settlement due to preload and surcharge fill placement has diminished to
acceptable rates. Proper monitoring of settlements during fill placement and during the
G e o E n g i n e e r s 3 File No.0340-014R01/0392
preloading period is essential. A monitoring program is necessary so that time-rate of settlement
information can be obtained and the effective time of completion of surcharge evaluated.
SITE PREPARATION, PRELOADING AND EARTHWORK
Site Preparation
i
We recommend that building and pavement areas be stripped of all vegetation,root systems
and topsoil. Based on our explorations, the stripping necessary will generally be on the order
of 6 to 12 inches, but areas requiring greater stripping depths should be expected. The
' underlying silty sand fill contains a high percentage of fines (silt) and is very moisture-sensitive.
Operation of equipment on this soil will be difficult, if not impossible, when wet. If the stripping
operations cause disturbance of the underlying fill, additional excavation may be necessary.
Disturbance of the shallow subgrade soils should be expected if site preparation work is done
during periods of wet weather. Material from the stripping operations should be disposed of off-
site or used for landscaping purposes, if practical.
The site should be graded to a generally level surface once stripping has been completed.
This grading should be done to enhance drainage from the site and prevent ponding of water in
areas to receive additional fill. All pieces of debris and rubble larger than about 6 inches in
maximum dimension should be removed and disposed of off site.
The exposed subgrades in roadway, parking and building areas should be evaluated after
initial site grading is complete. Proofrolling with heavy rubber-tired construction equipment
should be used for this purpose. The site should be proofrolled only during dry weather.
Probing should be used to evaluate the subgrade during periods of wet weather. Any soft areas
noted during proofrolling or probing should be excavated and replaced with compacted structural
fill.
We recommend that temporary roads and laydown areas be constructed to reduce the risk
of disturbing the subgrade soils. In our opinion, temporary roads should consist of 12-18 inches
of quarry spalls or structural fill over a geotextile. The geotextile should be a woven fabric
intended for soil separation and reinforcement within roadway embankments. The design
pavement sections specified in a subsequent section of this report are not intended to support
heavy construction traffic. If pavement or subbase is placed while building construction is still
in progress the areas of pavement or subbase should be roped off to prevent vehicle access. This
jis to reduce the risk of softening of the subgrade, contamination of the subbase soils or pavement
failure.
As described in a subsequent section of this report, we recommend that all footings be
founded on a minimum thickness of structural fill. The excavation required to achieve this
thickness should be accomplished after the existing fill surface has been prepared but prior to
placing additional fill in the building areas.
Effective erosion and sedimentation controls should be implemented during construction so
that impacts to the on-site wetlands and adjacent properties are minimized. In our opinion, the
G e o E n g i n e e r s 4 File No.0340-014R01/0392
erosion potential of the on-site soils is high. The erosion and sedimentation control measures
used for this project should be in accordance with the requirements of City of Renton.
Preloading
fGeneral. We estimate that without preloading the building areas the structures could
' experience total settlements during and following construction on the order of 3 to 5 inches and
1 differential settlements of 2 to 3 inches, depending on actual building load distributions.
i
Settlements of this amount are generally unacceptable for structures such as those proposed for
this site. We recommend preloading the building areas of the site to reduce postconstruction
r
settlements. Additional loading (surcharge) is also recommended to speed the rate of induced
settlements.
Preloading involves placing excess fill (above the fill required for site grading) over the
proposed building areas prior to construction. The excess fill is designed to simulate all, or a
portion of, the areal loads which will be imposed by the structure and design floor loads.
Surcharge loads include any additional loads applied in excess of those required to simulate the
total areal structure and design floor loads. The thickness of preload and surcharge fill and the
time it remains in place depends on soil conditions, design building loads, and the amount of
postconstruction settlement the structure can tolerate.
Settlements should be monitored during the preload period using settlement plates. After
the desired consolidation is achieved, the preload and surcharge fill is removed and the building
foundations and floor slabs constructed. The preload and surcharge fill is typically used to
complete other earthwork outside the building areas. The amount of excess import fill which
would need to be removed from the site can frequently be reduced or eliminated by coordinating
preload quantities and site grade quantities. With a properly designed, constructed and monitored
preload and surcharge program, much of the postconstruction settlement which would otherwise
occur due to building and floor loads is eliminated. Some postconstruction settlements should
still be expected as a result of recompression of the soil and continued secondary consolidation
of the layers of peat and organic silt.
Preload and Surcharge Fill. We recommend that the preload and surcharge fill height
be 4 feet in slab and footing areas. These estimates are based on the assumption that design floor
loads will be 250 psf and design footing pressure will be 2,500 psf. For design floor loads of
500 psf, a preload and surcharge fill height of 6 feet is recommended. The full height of the fill
1 should extend beyond the building foundation lines by 5 feet and then slope down to the
l surrounding grade at about 1H:1 V (horizontal to vertical). It is necessary to compact the fill only
to the degree necessary for equipment mobility. We recommend that the same material specified
for structural fill in a following section be used for the preload and surcharge fill. This will
allow its use as structural fill in other areas once it is removed.
We expect that the majority of the settlement will occur within about 4 to 6 weeks after the
full height of fill is in place. We estimate that postconstruction settlements due to the areal fill
G e o E n g i nee r s 5 File No.034MI4-R01/0392
and floor loadings will be on the order of 1 inch. This settlement is expected to occur over a
period of several years.
Settlement Monitoring. A typical preload monitoring program consists of installing
j settlement plates at selected locations in the building areas and surveying the top of rods welded
to these plates prior to, during and after the fill is placed. The survey data is used to prepare
settlement versus time plots. By extrapolating these plots, we can refine our estimates of when
the preload fill can be removed.
The settlement plates should be installed once initial site grading is completed and prior to
placing structural fill for building pads. Typical settlement plate details and monitoring
recommendations are presented in Figure 4. We expect that significant variation in settlement
will occur across the site. We recommend that settlement plates be laid out along the building
centerlines and be spaced at no more than 100 feet. The plates should be placed no closer than
50 feet in from the edge of the building and should cover any irregularly shaped portions of the
buildings. We should review the final settlement plate layout before they are installed. Initial
elevation readings of the settlement plates must be obtained when they are placed and before any
fill is placed. If this is not done, the initial settlements of the fill pad will not be recorded and
the value of subsequent observations diminished because the total magnitude of settlement will
be unknown. The elevations of the settlement plates should be determined on Monday,
Wednesday and Friday during fill placement and twice weekly for the first two weeks after the
fill is in place. Weekly readings will be adequate after this period.
The presence of settlement rods extending above the fill will inhibit the mobility of
earthmoving equipment. The contractor will have to exercise care to avoid damaging the rods.
If the rods are damaged during site grading operation the contractor should repair them at once
and reestablish the plate elevation to allow continued monitoring.
Structural Fill
All new fill in building and pavement areas should be placed and compacted as structural
fill. The suitability of soil for use as structural fill will depend on its gradation and moisture
content. In our opinion, the on-site soils are not suitable for use as structural fill and imported
sand and gravel will be required. We recommend that all imported sand and gravel contain less
than 5 percent fines (material passing U.S. Standard No. 200 sieve) by weight relative to the
fraction of the material passing the 3/4-inch sieve. This material should be free of debris,
organic contaminants and rock fragments larger than 6 inches.
All structural fill should be mechanically compacted to a firm, nonyielding condition.
Structural fill placed in building areas should be compacted to at least 95 percent of the maximum
dry density in accordance with ASTM D-1557. Pavement area fill, including utility trench
backfill, should be compacted to at least 90 percent, except for the upper 2 feet below finished
subgrade surface, which should be compacted to 95 percent. Structural fill should be placed in
loose lifts not exceeding 8 to 10 inches in thickness. Each lift should be conditioned to the
G e o E n g i n e e r s 6 File No.0340-014R01/0392
proper moisture content and compacted to the specified density before placing subsequent lifts.
We recommend that a representative from our firm be present during proofrolling and/or
probing of the exposed subgrade soils in building and pavement areas, and placement of structural
fill. Our representative will evaluate the adequacy of the subgrade soils and identify areas
needing further work, perform in-place moisture-density tests in the fill to determine if the work
is being done in compliance with the compaction specifications, and advise on any modifications
to procedure which might be appropriate for the prevailing conditions.
1
1
FOUNDATION SUPPORT
We recommend that the new buildings be supported on conventional spread footings bearing
on a pad of structural fill with a minimum thickness of 2 feet or one-half the width of the footing,
whichever is greater. The structural fill pad will provide more uniform bearing support than the
existing fill soils and will reduce footing settlements. The zone of structural fill should extend
laterally beyond the footing edges a horizontal distance at least equal to the thickness of the fill.
Excavation for and placement of this fill should be done prior to construction of the building pad
fill and preloading so that the subsequent footing construction can be accomplished with less
disturbance to the building pad fill.
Loose or disturbed soils not removed from excavations for the structural fill beneath
footings will contribute to increased settlements. The silty material encountered in our
explorations is susceptible to disturbance. Additional excavation may be required at soft and
disturbed areas to provide a suitable bearing surface for the structural fill if the existing fill
cannot be compacted. The exposed soils must be protected from softening or other disturbance.
Structural fill should be placed as soon as each excavation is completed. When footings are
constructed, the exposed bearing surface should also be recompacted.
We recommend that exterior footings be founded at least 18 inches below lowest adjacent
finished grade. Interior footings should be founded a minimum of 12 inches below top of slab.
Continuous wall footings and individual column footings should have minimum widths of 24
inches and 36 inches, respectively. The recommended allowable bearing pressure for footings
supported on properly prepared structural fill is 2,500 psf. The allowable soil bearing pressure
is for the total of dead plus long-term live loads and may be increased by up to one-third for
short-term live loads such as wind or seismic forces.
We estimate that settlements of footings founded on structural fill as recommended will be
in the range of 3/4 to 1 inch, depending on actual foundation loads and underlying soil
( conditions. Much of the settlement due to applied dead loads will occur within a short time after
the walls and roof structure is in place. Postconstruction footing settlements should be less than
1/2 inch. Maximum differential settlements between adjacent comparably loaded individual
column footings or along a 50-foot length of wall footing should also be less than 1/2 inch. We
recommend that we be retained to review our estimates of expected settlement performance of
individual structures once design column and wall loads have been determined.
G e o E n g i n e e r a 7 File No.0340-014R01/0392
We recommend that all excavations for the fill pad and for footing construction be observed
by a representative from our firm to determine if the work is completed in accordance with our
recommendations and that subsurface conditions are as expected.
LATERAL RESISTANCE
Lateral loads on building footings can be resisted by passive resistance on the sides of
the footings and by friction on the base of the footings and slab. Passive resistance should be
evaluated using an equivalent fluid density of 300 pounds per cubic foot (pcf) where footings are
surrounded by structural fill compacted to 95 percent of maximum dry density as recommended
above. Passive pressure resistance should be calculated from the bottom of adjacent floor slabs
or paving or below a depth of 1 foot where the adjacent area is unpaved, as appropriate.
Frictional resistance can be evaluated using 0.4 for the coefficient of base friction against footings
and the building slab. The above values incorporate a factor of safety of about 1.5.
FLOOR SLAB SUPPORT
We recommend that the floor slabs be founded on a minimum of 1 foot of structural fill.
Any areas disturbed by construction activities should be recompacted before proceeding with slab
construction.
We recommend that a base course consisting of 4 inches of free-draining gravel containing
less than 3 percent fines be placed beneath the slab to provide uniform support and serve as a
capillary break to reduce moisture migration through the slab. This layer can be included as part
of the 1-foot minimum thickness of structural fill recommended above. In our opinion, a vapor
barrier such as plastic sheeting is not needed beneath the slab if the structural fill consists of clean
sand and gravel as previously specified.
Postconstruction settlement of slabs supported as recommended due to the applied floor
loads should be in the range of 1/2 to 1 inch provided the area has been properly preloaded.
These settlements may occur over a period of several years, depending on load history in the
buildings. Differential settlements of the floors depend, in part, on how uniformly the buildings
are loaded. We recommend that the slab be reinforced to reduce the potential for cracking due
to differential settlements.
{ PAVEMENTS
The exposed fill subgrade in pavement areas should be proofrolled or otherwise examined
to detect areas of soft subgrade or unsuitable soils. Soft or disturbed areas which develop in the
subgrade should be removed and replaced with granular fill compacted as recommended to
provide adequate pavement support. The thickness of additional sand and gravel fill required will
depend upon the firmness of the subgrade at specific locations and should be evaluated during
construction. In soft subgrade areas, we recommend that consideration be given to placing a
woven geotextile between the native soils and the structural fill as a separation layer.
G e o E n g i n e e r s 8 File No.0340-014-RO1/0342
Provided the subgrade is prepared as recommended and that pavement construction is done
during a period of extended dry weather, we recommend that the pavement section in automobile
parking areas consist of minimum thicknesses of 2 inches of Class B asphalt concrete, 4 inches
of clean crushed rock base, and a subbase consisting of 8 inches of structural fill. In roadway
and truck loading areas, the minimum thicknesses should be 3 inches of asphalt concrete,6 inches
t of crushed rock base and 8 inches structural fill. The structural fill should meet the requirements
r
previously specified for gradation and compaction.
The crushed rock base course and granular fill should each be compacted to at least
95 percent of the maximum dry density determined in accordance with ASTM D-1557. It is
important to pavement performance that backfill in utility trenches also be compacted as specified
for structural fill.
The above pavement section recommendations are based on having a relatively dry and
stable subgrade on which to place the subbase, base course and paving. Some differential
settlement of pavement areas is expected due to the variable nature of the existing fill and
underlying soft soils. We recommend that final paving be delayed as long as possible once the
subgrade has been prepared and the structural fill subbase has been placed to allow for some
settlement to occur.
DRAINAGE CONSIDERATIONS
We expect that shallow perched ground water could be encountered during footing and
utility excavation. We anticipate that this water can be temporarily handled during construction
by ditching and sump pumping, as necessary. All collected water should be safely routed to
suitable discharge points.
Roof drains should be tightlined and routed to suitable discharge points. All paved and
landscaped areas should be graded so that surface drainage is directed away from the buildings
to appropriate catch basins.
LIMITATIONS
We have prepared this report for Puget Western, Inc. and other members of the project
_ team for use in design of portions of the planned development. The data and report should be
provided to prospective contractors for bidding or estimating purposes, but our report,
conclusions and interpretations should not be construed as a warranty of the subsurface
conditions.
The project was in the design development stage at the time this report was prepared. We
expect that further consultation regarding specific design elements will be necessary. When the
design has been finalized, we recommend that GeoEngineers be retained to review the final
design drawings and specifications to see that our recommendations have been interpreted and
implemented as intended.
G e,o E n g i v e e r s 9 file No.0340-014R01/0392
Our scope does not include services related to construction safety precautions and our
recommendations are not intended to direct the contractor's methods, techniques, sequences or
procedures, except as specifically described in our report for consideration in design.
There are possible variations in subsurface conditions between the locations of explorations
and also with time. A contingency for unanticipated conditions should be included in the project
t budget and schedule. Sufficient monitoring, testing and consultation should be provided by our
firm during construction to determine if the conditions encountered are consistent with those
indicated by the explorations, to provide recommendations for design changes should the
conditions revealed during the work differ from those anticipated, and to evaluate whether or not
earthwork and foundation installation activities comply with the contract plans and specifications.
Within the limitations of scope, schedule and budget, our services have been executed in
accordance with generally accepted practices in this area at the time the report was prepared. No
other conditions, express or implied, should be understood.
O ►
We appreciate the opportunity to be of service to you. If you have any questions
concerning this report or if we can provide additional services, please call.
Respectfully submitted,
GeoEngineers, Inc.
R Ttj�,
'G `�W ASS
IL , M adden
x
Proj Engineer
0 0747-7 �� �4�
�OISVF, G~ l
O N AL
Ja K. Tuttle
EXPiREs incipal
JJMJKT:ira
DOC M: 0340014.R
f
G e o E n g i n e e r s 10 File No.0340-014-ROl/0392
\ Golf Course �� .1" �7 1 _testa
30
age
//�7• /11'i�\.� 'M 16• ° 1 fo i Gov
1 x�... ., 7 • ;
r y7rl�.
ti j
Track
SITE � 1
E-- l
�V"I 1
25 .30 `. �' "ISM 12 2
16 17
I:= 1
.Orillia ' 1 -'" '
N
q
j v 0 2000 4000
\ ti
SCALE IN FEET
Reference: USGS 7.5' topographic quadrangle map entitled 'Renton, Washington,' dated 1973.
i o \� VICINITY MAP
Geo�O Engineers
ti FIGURE 1
0
S. W. 23RD STREET
o 0
i
I to
�.= o
i:W i I
I
wETuno AREA 7
LLJ
41 Q
41
W
1 rrrr.� _
Q � V 4
Uj
J & 4156qti J
/ Al `- a
�l� -TP-1
f-
^� rw
\ Fi - }-TP-2 1 n W
04� BUILDING '�' a'
- � �
LAND`ARFJ1 3
/ t DC90-04
U.. 3 ----- -9 —I_I-
a
Ir; yr
`� 1,
- - i9v�g 3� "'I BUILDING'' "K.LM.410
Ne
w
n, EXPLANATION: �-
B-1+ BORING BY GEOENGINEERS FOR CURRENT STUDY .
TP-2-{ }- i
TEST PIT BY GEOENGINEERS FOR CURRENT STUDY ,I
I, 0 100 200
3 - TEST PIT BY GEOENGINEERS FOR PREVIOUS STUDIES
DATED 10/26/81 AND 02/22/82 SCALE IN FEET
BORING By
2/82 INEERS FOR PREVIOUS STUDY
DATED 02/22/82 Reference: Map by Lance Mueller&Associates entitled'Puget Western Business Park
a Renton, Washington,'revision dated 05/0t/91.
a B90-01 + BORING BY OTHERS FOR PREVIOUS STUDIES '
4 DC90-03 Z� DUTCH CONE BY OTHERS FOR PREVIOUS STUDIES SITE PLAN - NORTH
Geo�� SITE
FIGURE 2
now
F�9J�e 2>
see
0 i / - WETl.ANUAREA2
= / / (PARTIAL Flu.06 ACREsr "f°
L
w B90-01 = � TP-3
— 4
1 r— z
` 14 t
�- 20 —� �; " BUILDING '3' Iri
f�
TP-
W -- — --- — -
8
�
Z \ ,_lJN tiTA»J.�cD (i��� / B-3 y
AWA _—L'l✓_ fto 6 '
LLI 4-6
•-- ---� ' �! w(- Vic— +- ------- .30 7.vw `�--0- ' I
Q w ,e-�-� �_6 I e 4Uj
-�-13 I - —
14
3'7
DC90-03
15
-„ ; BUILDING '6'
! 4-9
BUILDING 7 / ( w
7 _. ..
19 5 r PA K a'
-ruu REA ,,o.rz �.or.s•
aP Tao P=F`L -- ,g - --- ----- \r _\
DC90-02 ° ° - -
° ° J / .
Piu �F<rYr) _
( WEfLAIID ARfA 8/
J \ awea,�e+wEr4a
All
__- ITV \ • Y•J /
' 1
2 uFcR WI 42' Ws.i � b
p.
EXPLANATION:
S.W. 27TH STREET
B-3+ BORING BY GEOENGINEERS FOR CURRENT STUDY
N o 100 200
TP-4* TEST PIT BY GEOENGINEERS FOR CURRENT STUDY
o SCALE IN FEET
17-* TEST PIT BY GEOENGINEERS FOR PREVIOUS STUDIES
DATED 10/26/81 AND 02/22/82
1 BORING BY GEOENGINEERS FOR PREVIOUS STUDY
i Reference: Map by Lance Mueller&Associates entitled*Puget Western Business Paris,
DATED 02/22/82 Renton,WasFwngton.'revision dated 05/01/91.
B90-01 BORING BY OTHERS FOR PREVIOUS STUDIES
o \� SITE PLAN - SOUTH
DC90-03,ni DUTCH CONE BY OTHERS FOR PREVIOUS STUDIES G e o��Engineers FIGURE 3
0
MEASUREMENT ROD, 1 /2" 0 PIPE
OR REBAR
CASING, 2" 0 PIPE
(SET ON PLATE, NOT FASTENED)
EXISTING COUPLING WELDED TO PLATE
GROUND SURFACE
1 SETTLEMENT PLATE,
16" X 16" X 1 /4"
r
SAND PAD IF NECESSARY
(NOT TO SCALE/
NOTES :
1 . INSTALL MARKERS ON FIRM GROUND OR ON SAND PADS IF
NEEDED FOR STABILITY . TAKE INITIAL READiIJG ON TOP
OF ROD AND AT ADJACENT GROUND LEVEL PRIOR TO PLACE-
MENT OF ANY FILL .
2 . FOR EASE IN HANDLING, ROD AND CASING ARE USUALLY
INSTALLED IN 5-FOOT SECTIONS . AS FILL PROGRESSES,
COUPLINGS ARE USED TO INSTALL ADDITIONAL LENGTHS .
CONTINUITY IS MAINTAINED BY READING THE TOP OF THE
MEASUREMENT ROD, THEN IMMEDIATELY ADDING THE NEW
SECTION AND READING THE TOP OF THE ADDED ROD . BOTH
READINGS ARE RECORDED .
N 3 . RECORD THE ELEVATION OF THE TOP OF THE MEASUREMENT
M ROD IN EACH MARKER AT THE RECOMMENDED TIME INTERVALS .
4 EACH TIME, NOTE THE ELEVATION OF THE ADJACENT FILL
l SURFACE .
4 . READ THE MARKER TO THE NEAREST 0 . 01 FOOT, OR 0 . 005
{ a FOOT IF POSSIBLE . NOTE THE FILL ELEVATION TO THE
° NEAREST 0 . 1 FOOT .
a
5 . THE ELEVATIONS SHOULD BE REFERENCED TO A TEMPORARY
BENCHMARK LOCATED ON STABLE GROUND AT LEAST 100 FEES
o FROM THE EMBANKMENT .
i
\� SETTLEMENT PLATE DETAIL
G e o��Engineers FIGURE 4
i
r
r
APPENDIX A
J ,
APPENDIX A
FIELD EXPLORATIONS AND LABORATORY TESTING
FIELD EXPLORATIONS
Subsurface conditions were explored by excavating seven test pits and drilling three test
borings at the site. The test pits were excavated on January 14, 1992 using a rubber-tired
backhoe. The test borings were drilled on January 16, 1992 using truck-mounted, hollow-stem
auger drilling equipment. Locations of the explorations were determined in the field by
measuring distances from site features. Ground surface elevations were determined from
topography shown on the site plan entitled "Puget Western Business Park, Renton, Washington"
by Lance Mueller & Associates, revision dated 05/01/91. The locations of the explorations are
shown on the Site Plan, Figures 2 and 3.
The test pit excavations and test borings were continuously monitored by an engineer from
our firm who examined and classified the soils encountered, obtained representative soil samples,
observed ground water conditions and prepared a detailed log of each exploration. Grab samples
were obtained from the various soil layers encountered in the test pits. A 3-inch-outside-
diameter, heavy-duty, split-barrel sampler with brass liner rings was used to obtain relatively
undisturbed samples. The blow counts resulting from driving this sampler with a 300-pound
hammer falling 30 inches are roughly equivalent to those from the Standard Penetration Test.
The number of blows required to drive the sampler the last 12 inches, or other indicated distance,
is recorded on the boring logs. Soils were classified in general accordance with the classification
system described in Figure A-1. A key to the boring log symbols is presented in Figure A-2.
The test boring logs are presented in Figures A-3 and A-5 and the test pit logs are presented
in Figures A-6 through A-9. These logs are based on our interpretation of the field and
laboratory data and indicate the various types of soils encountered. They also indicate the depths
at which the soils or their characteristics change. The densities noted on the test boring logs are
based on the blow count data obtained in the borings. The densities noted on the test pit logs are
based on the difficulty of digging, probing with a 1/2-inch-diameter hand probe, and our
experience and judgment.
LABORATORY TESTING
The soil samples obtained from the test pits and test borings were further examined in our
laboratory. Moisture content determinations were made on selected samples from the test pits
for correlation purposes. The results of these determinations are presented in Figure A-10.
Moisture and density tests were also completed on samples obtained from the test borings. The
results of these tests are presented on the boring logs. In addition, two consolidation tests were
completed on samples obtained from the test borings. The results of these tests are presented in
Figure A-11. Atterberg limits test results for a sample of the silt are presented in Figure A-12.
G e o E n g i n e e r s A - 1 File No.0340-014-R01/0392
SOIL CLASSIFICATION SYSTEM
MAJOR DIVISIONS GROUP GROUP NAME
SYMBOL
WELL-GRADED GRAVEL,FINE TO
COARSE GRAVEL CLEAN GRAVEL GW COARSE GRAVEL
GRAINED GP POORLY-GRADED GRAVEL
SOILS
MORE THAN 60% GRAVEL GM SILTY GRAVEL
OF COARSE FRACTION WITH FINES
RETAINED
ON NO. 4 SIEVE GC CLAYEY GRAVEL
MORE THAN 50%
RETAINED ON WELL-GRADED SAND, FINE TO
NO. 200 SIEVE SAND CLEAN SAND SW COARSE SAND
SIP POORLY-GRADED SAND
MORE THAN 50% SAND SM SILTY SAND
OF COARSE FRACTION WITH FINES
PASSES
NO. 4 SIEVE SC CLAYEY SAND
SILT AND CLAY ML SILT
FINE INORGANIC
GRAINED CL CLAY
SOILS LIQUID LIMIT
LESS THAN 60 ORGANIC OL ORGANIC SILT, ORGANIC CLAY
SILT AND CLAY MH SILT OF HIGH PLASTICITY, ELASTIC SILT
MORE THAN 50% INORGANIC
PASSES NO. 200 SIEVE CH CLAY OF HIGH PLASTICITY, FAT CLAY
LIQUID LIMIT
60 OR MORE ORGANIC OH ORGANIC CLAY, ORGANIC SILT
HIGHLY ORGANIC SOILS PT PEAT
NOTES: SOIL MOISTURE MODIFIERS:
1. Field classification Is based on Dry - Absence of moisture, dusty, dry
visual examination of soli in general to the touch
accordance with ASTM D2488-84.
Moist - Damp, but no visible water
2. Soil classification using laboratory
tests is based on ASTM D2487-85. Wet - Visible free water or saturated,
usually soil is obtained from
3. Descriptions of soil density or below water table
consistency are based on
interpretation of blowcount data,
visual appearance of soils, and/or
test data.
rn
i
I �
� p
H
W
Ito. SOIL CLASSIFICATION SYSTEM
G e o E n o i n e e r s
\�/ b FIGURE A-1
LABORATORY TESTS: SOIL GRAPH:
AL Atterberg limits
CP Compaction SM Soil Group Symbol
CS Consolidation (See Note 2)
DS Direct shear
GS Grain - size Distinct Contact Between
%F Percent fines Soil Strata
HA Hydrometer analysis
Gradual or Approximate
SK Permeability
Location of Change
SM Moisture content
Between Soil Strata
MD Moisture and density
SP Swelling pressure Water Level
TX Triaxial compression Bottom of Boring
UC Unconfined compression
CA Chemical analysis
BLOW-COUNT/SAMPLE DATA:
22 ■ Location of relatively
Blows required to drive a 2.4-inch I.D. undisturbed sample
split-barrel sampler 12 inches or
other indicated distances using a 12 ® Location of disturbed sample
300-pound hammer falling 30 inches.
17 0 Location of sampling attempt
with no recovery
10 0 Location of sample obtained
Blows required to drive a 1.5-inch I.D. in general accordance with
(SPT) split-barrel sampler 12 inches Standard Penetration Test
or other indicated distances using (ASTM D-1586) procedures
140-pound hammer falling 30 inchesJ<.
26 m Location of SPT sampling
attempt with no recovery
® Location of grab sample
"P" indicates sampler pushed with
weight of hammer or against weight
of drill rig.
NOTES:
( 1. The reader must refer to the discussion in the report text, the Key to Boring Log Symbols
and the exploration logs for a proper understanding of subsurface conditions.
2. Soil classification system is summarized in Figure A-1.
m
KEY TO BORING LOG SYMBOLS
Geoff Engineers
�� FIGURE A-2
TEST DATA BORING B-1
k
o DESCRIPTION
Moisture Dry it a 6 Group
Content Density �U Symbol Surface Elevation(ft.) : 15.0
I.ab Testa ('%) c�
0 SM Brown silty fine to medium sand with gravel and scattered organic 0
SM matter(medium dense,moist)(fill)
Gray silty fine to medium sand with gravel(medium dense,moist)
(fill)
MD 20 100 22
5 5
{
30 ® Grades to wet
r
PT Brown fibrous peat(soft,wet)
10 10
SM 70 P I I OL Dark brown organic silt and silt with peat(soft,wet)
I I ML
SM 98
I �
SM 168
15 I I 15
I I I
uj I I
w
LL I I
MD 38 84 7 I I
Black to gray silty fine sand to fine sand with silt and occasional
a : SP—SM organic matter(loose,wet)
O 20 20
MD 26 97 2
25 25
SP— Gray fine to medium sand with silt(loose to medium dense,wet)
w 4 SM
N
30 30
U
M
m
l
l
MD 24 99 10 Decreasing silt content
35 35
I
22
a
o
c 40 40
Note:See Figure A-2 for explanation of symbols
\� LOG OF BORING
Geo\w Engineers
FIGURE A-3a
TEST DATA BORING B-1
(Continued)
DESCRIPTION
Moisture D 0 S
Group
Content Dry .2 E
co 10 mbol
40—Lab Tests (Pef) U y
40
MD 21 105 10 Scattered shell fragments
45 — —45
25
50— 50
MD 30 91 25
55 — SW Gray fine sand with gravel and occasional coarse sand(dense,wet)
—55
LU
LL
Z
45
LU
60— —60
SP— Gray fine to medium sand with silt and occasional coarse sand and -
SM fine gravel(very dense,wet)
MD 19 109 51
Boring completed at 63.0 feet on 01/16/92
65— Ground water encountered at 7.5 feet during drilling —65
70— —70
M
75 75
C�
80 LBO
Note:See Figure A-2 for explanation of symbols
LOG OF BORING
Geo -MI-i
...Enoineers
FIGURE A-3 b
TEST DATA BORING B-2
m
DESCRIPTION
G ° Group
Contente DMity .2 0 ce Symbol Surface Elevation(ft.) : 16.0
Lab Teats (%) cf) CQU
0 SM Brown silty fine to medium sand with scattered gravel and a trace 0
SM of organic matter(medium dense,moist)(fill)
Gray silty fine to medium sand with gravel and construction debris
(medium dense,moist)(fill)
MD 15 94 25 ■
5 5
r
6
10 10
s PT Dark brown peat and organic silt(soft,wet)
MD 260 19 4 ■ OL
P
CS 178 25
tea=
15 MH Gray to dark brown organic silt to silt with scattered fibrous 15
OH organic matter and interbedded fine to medium sand(soft,wet)
Uj
LLIJ
L III
MD, 60 62 2 ■ III
a
AL
p 20 SM Brown silty fine sand(medium dense,wet) 20
SM Gray to black silty fine sand to silt with a trace of organic matter
MD 34 85 22 ■ ML (medium dense,wet)
25 25
SM Gray silty fine to medium sand(medium dense,wet)
N
26 ■ - •••• SP Gray fine to medium sand with occasional coarse sand and scattered
shell fragments(medium dense,wet)
30 30
U
17
35 SP— Gray fine to medium sand with silt and occasional coarse sand 35
t SM (medium dense,wet)
1
10 ■
v
0
40 40
O Note: See Figure A-2 for explanation of symbols
� LOG OF BORING
Geo\�Enbineers FIGURE A-4 a
TEST DATA BORING B-2
(Continued)
DESCRIPTION
Moisture Dry 3 Group
Content Density .2 symbol
40 Lab Tests (%) cf) 40
MD 23 101 39 :
Boring completed at 44.0 feet on 01/17/92
45 Ground water encountered at 8.0 feet during drilling 45
r
50 50
55 55
F-
w
w
w
Z_
2
F—
a
p 60 60
65 65
Z
N_
Ci
70 70
U
S y
L
75 75
0
a
0
d 80 80
Note:See Figure A-2 for explanation of symbols
�� LOG OF BORING
Geo.w Engineers
FIGURE A-4 b
TEST DATA BORING B-3
DESCRIPTION
Moisture Dry o a Group
Content Density -U Symbol Surface Elevation(ft.) : 18.0
Lab Tests (%) cf)
0 : SM Brown silty fine to medium sand with gravel and organic matter 0
SM (medium dense,moist)(fill)
Brown to gray silty fine to medium sand with gravel,concrete
pieces and scattered organic matter(medium dense,wet)(fill)
MD 22 94 18
t
5 5
8 E
10 10
6
PT Brown fibrous peat(soft,wet)
0<
CS 97 44 4 OL Gray organic silt with peat(soft,wet)
SM Brown silty fine sand(loose to medium dense,wet)
15 15
uj
w
u-
Z
MD 28 94 20 SM Grayish brown silty fine to medium sand with a trace of organic
matter and fine sandy silt(medium dense and stiff,wet)
a
0 20 20
4
SM Gray silty fine to medium sand interbedded with lenses of gray silt
25 ML (loose and soft,wet) 25
N
MD 22 96 3
30 30
SP— Gray fine to medium sand with silt and scattered shell fragments
mSM (medium dense,wet)
10
35 35
Q MD 23 101 23
v
0
3 40 40
a
Note: See Figure A-2 for explanation of symbols
�� W LOG OF BORING
Geo*P—A Engineers
FIGURE A-5a
TEST DATA BORING B-3
(Continued)
DESCRIPTION
Moisture Dry o a Group
Content Deasity .2 h Symbol
40 Lab Tests (%) f) 40
I 10
45 45
i
37
Boring completed at 49.0 feet on 01/17/92
50 Ground water encountered at the ground surface during drilling 50
55 55
H
w
w
w
Z_
2
H
a
p 60 60
65 65
0
N
70 70
U
t0
N
75 75
1 �
a
6 so s0
° Note:See Figure A 2 for explanation of symbols
QR:� LOG OF BORING
Geo 1-o Engineers FIGURE A-5 b
DEPTH BELOW SOIL GROUP LOG OF TEST PIT
GROUND SURFACE CLASSIFICATION
(FEET) SYMBOL DESCRIPTION
TEST PIT 1
Approximate ground surface elevation: 16 feet
0.0- 1.0 SM Vegetation,root mass and brown silty fine to medium sand with occasional gravel,
concrete and wood fragments(loose,moist)(fill)
r1.0- 2.5 SP Gray fine to medium sand(loose,wet)
2.5- 10.0 MUSM Gray fine sandy silt to silty fine to medium sand with occasional concrete debris and
rebar(stiff and medium dense,moist)(fill)
10.0- 12.0 PT/OL Brown peat and organic silt with occasional sand(soft, moist)
Test pit completed at 12.0 feet on 01/14/92
Moderate ground water seepage observed at 1.0 feet
Disturbed soil samples obtained at 9.0 and 1.0 feet
TEST PIT 2
Approximate ground surface elevation: 16 feet
0.0- 1.0 SM Vegetation, root mass and brown silty fine to medium sand with gravel, concrete
debris and wood fragments(loose,moist)(fill)
1.0- 9.0 SM Gray silty fine to medium sand with gravel, concrete debris and wood fragments
(medium dense,moist)(fill)
9.0- 10.0 PT/OL Brown peat with organic silt and fine sand to organic silt(soft, moist)
Test pit completed at 10.0 feet on 01/14/92
No ground water seepage observed
Disturbed soil samples obtained at 0.5,5.0 and 9.0 feet
i
L
THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF
MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT.
(N� LOG OF TEST PIT
Geo ap.Engftieers FIGURE A-6
LOG OF TEST PIT
DEPTH BELOW SOIL GROUP
GROUND SURFACE CLASSIFICATION
(FEET) SYMBOL DESCRIPTION
TEST PIT 3
't Approximate ground surface elevation: 18 feet
0.0- 1.0 SM Vegetation, root mass and brown silty fine to medium sand with gravel and
occasional concrete debris(medium dense,moist)(fill)
4 1.0- 9.0 SM Gray silty fine to medium sand with gravel, concrete debris and occasional rebar
(medium dense,moist)(fill)
9.0- 9.5 PT/OL Brown peat and organic silt(soft, moist)
Test pit completed at 9.5 feet on 01/14/92
No ground water seepage observed
Disturbed soil sample obtained at 5.0 feet
TEST PIT 4
Approximate ground surface elevation: 17 feet
0.0- 1.0 SM Vegetation, root mass and brown silty fine to medium sand with gravel, brick
fragments and concrete debris(loose,wet) (fill)
1.0- 8.5 SM Gray silty fine to coarse sand with occasional gravel, brick fragments and concrete
debris(medium dense,moist)(fill)
8.5-9.5 PT/OL Brown peat with organic silt(soft, moist)
Test pit completed at 9.5 feet on 01/14/92
Moderate ground water seepage observed at 1.0 foot
Disturbed soil samples obtained at 1.0 and 6.0 feet
1 THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF
MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT.
LOG OF TEST PIT
Geo,00 Engineers FIGURE A-7
LOG OF TEST PIT
DEPTH BELOW SOIL GROUP
GROUND SURFACE CLASSIFICATION
(FEET) SYMBOL DESCRIPTION
TEST PIT 5
Approximate ground surface elevation: 17 feet
0.0- 1.0 SM Vegetation,root mass and brown silty fine to coarse sand with gravel and occasional
concrete debris(loose,wet) (fill)
t
1.0- 5.0 SM Gray silty fine sand with gravel and concrete debris(medium dense,moist)(fill)
Test pit completed at 5.0 feet on 01/14/92 due to refusal on large concrete debris
Ground water seepage observed at 1.0 foot
Disturbed soil sample obtained at 3.0 feet
TEST PIT 6
Approximate ground surface elevation: 16 feet
0.0- 1.0 SM Vegetation, root mass and brown silty fine to medium sand with gravel and
occasional concrete debris(loose,wet)(fill)
1.0- 8.0 SM Gray silty fine to medium sand with gravel and occasional concrete debris(medium
dense,moist)(fill)
8.0- 9.5 MIJOL Brown silt to organic silt with wood fragments(soft, moist)
Test pit completed at 9.5 feet on 01/14/92
Minor ground water seepage observed at 1.0 foot
Disturbed soil samples obtained at 2.0 and 9.5 feet
i
THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF
MEASUREMENTS ACROSS THE TEST Prr AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT.
eA
In. LOG OF TEST PIT
Geo\�Enameers FIGURE A-8
DEPTH BELOW SOIL GROUP LOG OF TEST PIT
GROUND SURFACE CLASSIFICATION
(FEET) SYMBOL DESCRIPTION
TEST PIT 7
Approximate ground surface elevation: 16 feet
1 0.0- 0.5 SM Vegetation,root mass and brown silty fine to medium sand with gravel and concrete
debris(loose,wet)(fill)
i 0.5- 7.5 SM Gray silty fine to medium sand with gravel and concrete debris (medium dense,
moist)(fill)
Test pit completed at 7.5 feet on 01/14/92 due to refusal on large concrete debris
Ground water seepage observed at 0.5 foot
Disturbed soil samples obtained at 3.0 and 5.0 feet
I
THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF
MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT.
LOG OF TEST PIT
Geo\`pEngineers FIGURE A-9
i
i
f
SUMMARY OF MOISTURE CONTENT DATA*
Test Sample
Pit Depth *Soil Moisture
Number feet Type Content
1 10.0 ML 24
1 11.0 PT 106
2 0.5 SP-SM 11
2 5.0 SM 22
2 9.0 PT 120
3 5.0 SM 12
4 1.0 SM 27
4 6.0 SM 17
5 3.0 SM 11
6 2.0 SM 9
6 9.0 PT 110
7 3.0 SM 13
7 5.0 SM 13
*.Refe.r to test ptt toes for.complete soil descriptigrt
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SUMMARY OF MOISTURE CONTENT DATA
Geo&Engineers FIGURE A-10
PRESSURE (LBS/FT2 x 103)
.1 .2 .3 .4 .5 1 2 3 4 5 10 20 30 40 50
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BOP, ING DEPTH SOIL MOISTURE DENSITY
KEY NUMBER (FT) CLASSIFICATION CONTENT (LBS/FT3)
B-2 14 DARK BROWN PEAT (PT) 1780 25
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B-3 13 ORGANIC SILT WITH PEAT .970 44
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CONSOLIDATION TEST RESULTS
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Earth consultants Inc.
Geotechnical Engineers.Geologists R Environmental Scientists
A,=Ccl
April 2, 1996
Revised April 4, 1996 1996 E-5576-5
Larkin �arl�in
15302 - 182nd Place Northeast
Woodinville, Washington 98072-9376 l�EIVE
Attention: Mr. Scott Larkin APR 3 0 7996
Subject: Geotechnical Consultation BUILDING DIVISION
Valley DC
East Valley Highway and Southwest 27th Street
Renton, Washington
Reference: GeoEngineers, Inc.
Geotechnical Engineering Study
File No. 0340-014-1301 , dated March 27, 1992
GeoEngineers, Inc.
Report of Geotechnical investigation
File No. 186-08, dated February 22, 1982
Dear Mr. Larkin:
At your request, we are pleased to present this letter summarizing our review of the
referenced geotechnical engineering studies. The purpose of our work was to review
the referenced study and provide additional geotechnical recommendations for the
current development plan.
Project History
There have been at least two different development plans for this site in the past
fourteen years. The referenced February 22, 1982 study was prepared for a storage
facility for the Puget Sound Power and Light Company. At that time, the site was
going to be developed with a single-story concrete tilt-up panel building. The
proposed building was to have a footprint of about 100,000 square feet.
The March 27, 1992 report was prepared for a planned seven-building business park.
The single-story buildings were to have footprints of 24,250 to 42,475 square feet
and to be of concrete tilt-up panel construction with dock-high floors.
1805 - 136th Place N.E., Suite 201, Bellevue, Washington 98005
Bellevue (206)643-3780 Seattle (206)464-1584 FAX (206) 746-0860 Tacoma (206)272-6608
Larkin E-5576-5
April 2, 1996
Revised April 4, 1996 Page 2
In late summer of 1992, earthwork construction began on the seven-building
development. In September and October of 1992 the Building 1 area was completely
filled and Building areas 2, 3 and 5 were partially filled. In August 1993, Building
area 2 was filled. The fill in Building areas 1 and 2 was placed to an elevation of
around twenty-three (23) to twenty-four (24) feet, or about two to three feet above
the planned finished floor elevation of twenty-one (21 ) feet. Five settlement monitors
were placed in the Building 1 area and three monitors were placed in the Building 2
area. No settlement monitors were placed in Building areas 3 and 5.
Settlement readings were obtained on a periodic basis from October 1992 through
August 1993. The results of our settlement readings during this period indicate the
Building 1 area settled 3.6 to 7.4 inches and the Building 2 area settled 1 .8 to 3.36
inches. The relatively smaller settlement at the Building 2 location is due to a shorter
settlement monitoring period. Our last set of settlement readings were taken on
August 11 , 1993. Another set of readings were taken by a surveyor last week.
When these latest readings are obtained, modifications to our recommendations may
be required.
Project Description
At this time, it is planned to develop the site with a single warehouse building. The
currently planned building will have a footprint of 459,450 square feet, encompassing
most of the area of the previously planned seven-building development. The building
will be one high-bay story in height with a dock-high concrete floor with a finished
floor elevation of twenty-one (21 ) feet. We understand floor loads will be on the
order of three hundred fifty (350) pounds per square foot (psf). We anticipate wall
and column loads will be typical for this type of construction, that is about four (4)
to six (6) kips per lineal foot and eighty (80) to one hundred (100) kips, respectively.
Three to four feet of fill will be required over much of the building area to reach floor
subgrade elevations. In some localized low lying areas, up to nine feet of fill will be
required.
If any of the above design criteria are incorrect or change, we should be consulted to
review the recommendations contained in this report. In any case, Earth Consultants,
Inc. (ECI) should be retained to perform a general review of the final design.
Earth Consuhants, Inc.
Larkin E-5576-5
April 2, 1996
Revised April 4, 1996 Page 3
Subsurface Conditions
GeoEngineers previously drilled eight (8) borings and excavated twenty-seven (27)
test pits at this site. The subsurface conditions consisted fill overlying the native soil
sequence of interbedded loose to medium dense silty fine sand, sandy silt and silt
(Unified Soil Classifications SM, ML, and ML). A layer of peat (PT) was encountered
in most of the test pits and borings. This compressible organic soil was generally
encountered at six to ten feet below grade and ranged from one to six feet thick. The
native soils are representative of the overbank river and river meander deposits
typically encountered in the Green River Valley.
Groundwater seepage was encountered at one to nine feet below grades.
Groundwater levels will fluctuate seasonally, and are typically higher in the wetter
winter months.
DISCUSSION AND RECOMMENDATIONS
Based on the results of our review, we generally concur with the recommendations
in the referenced soils investigation. As with the referenced report, we agree the
buildings can be supported on conventional spread and continuous footing foundation
systems bearing on two feet of structural fill after the successful completion of a
surcharge program. However, we differ with respect to the surcharge height.
The referenced reports recommend a surcharge height of four to six feet above
finished floor elevation. Based on our experience with the surcharge fills placed in the
previously planned Buildings 1 and 2 and the anticipated three hundred fifty (350) psf
floor loads, in our opinion, the surcharge height can be reduced to three feet above
finished floor elevation. We estimate a surcharge period of about three months. If
a shorter surcharge period is required, the height of the fill should be increased to five
feet for an estimated surcharge period of about six weeks. Some of the surcharge fill
may be obtained on-site by mining areas outside of the building footprint, then
replacing it after the surcharge is complete.
Earth Consultants, Inc.
Larkin E-5576-5
April 2, 1996
Revised April 4, 1996 Page 4
In our opinion, the surcharge in area of Building 1 and 2 is complete and these soils
can be incorporated into the new building footprint. However, the new surcharge
should overlap the Building 1 and 2 surcharge areas at least five feet. If the five foot
surcharge is used, the additional surcharge should be placed over these two pads.
We trust this letter meets your needs. If you have any questions, please call.
Respectfully submitted,
EARTH CONSULTANTS, INC.
Scott D. Dinkelman
ProjectVanager
Ro ert S. Levins
Principal ` AI
SDD/RSL/kml z�
a
Earth Consultants, Inc.