HomeMy WebLinkAboutSWP272195 CITY of F:ENTON
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NOV 9 1994
PREPARED FOR BU►Lot�v° DIVISION
TRAMMELL CROW COMPANY
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�< Douglas S. Lynne �, :?,
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Staff Engineer
Kyle R. Campbell, P.E. .c:`
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Manager of Geotechnical " C 7 4 sllk(kti
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GEOTECHNICAL ENGINEERING STUDY
PROPOSED WAREHOUSE
SOUTHWEST 27TH STREET
RENTON, WASHINGTON
E-3453-4
ta S August 19, 1994
V�larQ �Leu,Be , .
Earth Consultants, Inc.
1805 - 136th Place Northeast, Suite 101
Bellevue, Washington 98005
(206) 643-3780
Earth Consultants Inc.
Geotechnical Engineers,Geologists&Environmental Scientists
August 19, 1994 E-3453-4
Trammell Crow Company
5601 Sixth Avenue South
P. 0. Box 80326
Seattle, Washington 98108
Attention: Mr. Todd Timberlake
Dear Mr. Timberlake:
We are pleased to submit our report titled "Geotechnical Engineering Study, Proposed
Warehouse, Southwest 27th Street, Renton, Washington." This report presents the
results of our field exploration, selective laboratory tests, and engineering analysis, as
well as geotechnically related recommendations for the proposed site development.
The purpose and scope of our study was outlined in our proposal dated July 25,
1994.
Based on the subsurface conditions encountered at the project site, it is our opinion
that the proposed warehouse may be supported by shallow spread footings bearing
on a minimum of two feet of structural fill, provided that the recommendations
contained in this report are incorporated into the construction specifications. Due to
the potential for large settlements, the use of a surcharge program is recommended
to pre-consolidate the soft soils beneath the building.
If you or your consultants have any questions about the content of this report, or if
we can be of further assistance, please call.
Respectfully submitted,
EARTH CONSULTANTS, INC.
Kyle R. Campbell, P.E.
Manager of Geotechnical Services
DSL/KRC/kml
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
TABLE OF CONTENTS
E-3453-4
PAGE
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Project Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
SITE CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Subsurface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Laboratory Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
DISCUSSION AND RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . 3
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Site Preparation and Grading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Surcharge Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Seismic Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Lateral Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Slab-on-Grade Floors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Excavations and Slopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Site Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
. . . . . . . . . . . . . . . . . . . . . . . . . .
Utility Support and Backfill . . . . . . . . 12
Pavement Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Additional Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
APPENDICES
Appendix A Field Exploration
Appendix B Laboratory Testing
ILLUSTRATIONS
Plate 1 Vicinity Map
Plate 2 Test Pit Location Plan
Plate 3 Settlement Plate Detail
Plate 4 Utility Trench Fill
Plate 5 Typical Footing Subdrain Detail
Plate Al Legend
Plates A2 through A14 Test Pit Logs
Plate 131 Grain Size Analysis
Plate B2 Atterberg Limits
GEOTECHNICAL ENGINEERING STUDY
PROPOSED WAREHOUSE
SOUTHWEST 27TH STREET
RENTON, WASHINGTON
E-3453-4
INTRODUCTION
General
This report presents the results of the geotechnical engineering study for the proposed
warehouse located on Southwest 27th Street in Renton, Washington. The general
location of the site is shown on the Vicinity Map, Plate 1 . The purpose of this study
was to explore the subsurface conditions at the site and, based on the conditions
encountered, to provide geotechnical recommendations for the proposed site
development.
Project Description
At the time our study was performed, the site, the proposed structure, and
exploratory locations were approximately as shown on the Test Pit Location Plan,
Plate 2.
Based on information provided by Trammell Crow Company, it is proposed to develop
the parcel of land with a concrete tilt-up office/warehouse. We understand that fills
up to about six feet in depth will be necessary in order to provide the desired floor
elevation for the building. Based on our experience with similar structures, we
anticipate structural loading to be in the following ranges:
• Wall footings - 4 to 6 kips per lineal foot
• Maximum column load - 50 - 100 kips
• Slab loads - 200 - 250 pounds per square foot (psf)
If the above design criteria are incorrect or change, we should be notified and allowed
to review our recommendations in light of actual design information. In any case, it
is recommended that Earth Consultants, Inc. be retained to perform a general review
of the final construction design.
Earth Consultants, Inc.
GEOTECHNICAL ENGINEERING STUDY
Trammell Crow E-3453-4
• August 19, 1994 Page 2
SITE CONDITIONS
Surface
The site of the proposed facility is located on Southwest 27th Street in Renton,
Washington (see Plate 1, Vicinity Map). The rectangular parcel covers about eleven
and three-quarter acres; however, the proposed development is located in the
southern seven and two-thirds acres. The site is bounded by Southwest 27th Street
on the south, by an existing tilt-up warehouse on the west, by vacant property on the
north, and by Spring Brook Creek on the east.
At present, the site is vacant with grasses and minor amounts of brush covering the
existing surface. The site is generally level with a small drainage swale in the central
portion of the proposed construction area. This swale drains to Spring Brook Creek
on the east side of the site. Three piles of topsoil and miscellaneous debris were
observed on the site during our field exploration. The piles were in the southern and
east central portions of the site.
Subsurface
The site was explored by excavating thirteen test pits at the approximate locations
shown on Plate 2. Detailed descriptions of the conditions encountered at each
location explored are presented on the Test Pit Logs, Plates A2 through A14. A
description of the field exploration methods is included in Appendix A. Below is a
generalized description of the subsurface conditions encountered.
During our subsurface exploration, a five and one-half (5.5) to ten 0 0) foot thick layer
of fill was observed immediately underlying the surface. The fill generally consisted
of a thin veneer of loose silty.sand (Unified Soil Classification SM) overlying loose to
medium dense, brown poorly graded sand with silt (SP-SM). Beneath the fill, soft to
medium stiff, dark brown fibrous peat interbedded with organic silt (PT and OL) was
observed to depths ranging from ten (10) to thirteen (13) feet. The thickness of the
peat was observed to range from two and one-half (2.5) to four (4) feet. Laboratory
testing indicates peat moisture contents ranging from 83.0 to 216.2 percent, with
only one sample exhibiting a moisture content above 120.3 percent.
Underlying the peat and organic silt, a soft to medium stiff layer of gray silt with
varying plasticity (ML and MH) was observed to depths of fourteen (14) to fifteen
and one-half (15.5) feet beneath the existing grades. Test Pits TP-3 and TP-11
encountered a loose to medium dense, black silty sand beneath the silts. The
maximum exploration depth was fifteen and one-half 0 5.5) feet beneath the existing
grades. _
Earth Consultants. Inc.
GEOTECHNICAL ENGINEERING STUDY
Trammell Crow E-3453-4
August 19, 1994 Page 3
Based on review of the subsurface information contained in our study for the adjacent
warehouse, and our experience in the area, the encountered soils are expected to be
underlain by interbedded silts and sands.
Groundwater
Groundwater seepage was observed in all of the test pits except TP-5, TP-7, TP-8,
TP-11 and TP-12 at depths ranging from five and one-half (5.5) to eight and
one-half (8.5) feet below the existing ground surface. It is important to note that
groundwater seepage is not constant; thus, one may expect fluctuations in the
volume and location depending on the season, amount of rainfall, surface water
runoff, and other factors. Generally, groundwater seepage is greater during the
wetter winter months (typically October through May). Groundwater seepage is not
expected to have a significant impact on construction, except in deeper utility
trenches, or other deep excavations, unless the site is developed during periods of
heavy precipitation or during the winter months.
Laboratory Testing
Laboratory tests were conducted on several representative soil samples to verify or
modify the field soil classification of the units encountered and to evaluate the general
physical properties and engineering characteristics of the soils encountered. Visual
classifications were supplemented by index tests, such as sieve analysis and Atterberg
Limits, and moisture content tests on representative samples. The results of laboratory
tests performed on specific samples are provided either at the appropriate sample
depth on the individual test pit log or on a separate data sheet contained in
Appendix B. However, it is important to note that these test results may not
accurately represent the overall in-situ soil conditions; our geotechnical
recommendations are based on our interpretation of these test results.
The soil samples for this project will be discarded after a period of fifteen (15) days
following completion of this report, unless we are otherwise directed in writing.
DISCUSSION AND RECOMMENDATIONS
General
Based on the results of our study, it is our opinion that the site can be developed
generally as planned provided the recommendations contained in this report are
incorporated into the final design. In our opinion, total settlement of the existing peat
and underlying alluvial soils resulting from placement of new fill and building loads is
anticipated to be on the order of four to six inches. In order to minimize post
construction settlement, a surcharge program should be used.
Earth Consultants, Inc.
GEOTECHNICAL ENGINEERING STUDY
Trammell Crow E-3453-4
August 19, 1994 Page 4
The purpose of the surcharge program is to pre-induce settlements estimated to result
from new fill and building loads. The surcharge should be a minimum of two feet
above finished floor elevations. We anticipate completion of the surcharge program
in four to six weeks.
This report has been prepared for specific application to this project only and in a
manner consistent with that level of care and skill ordinarily exercised by other
members of the profession currently practicing under similar conditions in this area for
the exclusive use of Trammell Crow Company and their representatives. No warranty
is expressed or implied. It is recommended that this report, in its entirety, be included
in the project contract documents for the information of the contractor.
Site Preparation and Grading
Construction areas should be stripped and cleared of all existing vegetation, topsoil,
organic debris, and any other deleterious materials. The previously mentioned topsoil
and debris piles should be removed from the site or used in non-structural areas.
Stripped organic materials should not be mixed with any soils to be used as structural
fill. Following the stripping and clearing procedures, the earthwork operations can
commence to provide the design grades. The ground surface where structural fill is
to be placed should be proofrolled. All proofrolling should be performed under the
observation of a representative of ECI.
Soil in any loose or soft areas, if recompacted and still excessively yielding, should be
overexcavated and replaced with structural fill to a depth that will provide a stable
base beneath the general structural fill or suitable support for slabs.
Portions of the near-surface soils exposed in our test pits (silty sand and poorly graded
sand with silt, SM and SP-SM) .-are moisture sensitive due to their fines content.
Generally, soils with more than 5 percent fines are considered moisture sensitive. As
such, in an exposed condition they will become disturbed from normal construction
activity, especially when in a wet or saturated condition. Once disturbed, in a wet
condition, they will be unsuitable for support of foundations or pavements. Therefore,
during construction where these soils are exposed and will support new structures,
care must be exercised not to disturb their condition. If disturbed conditions develop,
the affected soils must be removed and replaced with a structural fill. The depth of
removal will be dependent on the level of disturbance developed during construction.
Earth Consultants, Inc.
GEOTECHNICAL ENGINEERING STUDY
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August 19, 1994 Page 5
Structural fill is defined as any compacted fill placed under foundations, roadways,
slabs, pavements, or any other load-bearing areas. Structural fill under foundations
should be placed in horizontal lifts not exceeding twelve 0 2) inches in loose thickness
and compacted to a minimum 90 percent of its maximum dry density in accordance
with ASTM Test Designation D-1557-78 (Modified Proctor). The fill materials should
be placed at or near the optimum moisture content. Fill under pavements and walks
should also be placed in horizontal lifts and compacted to 90 percent of maximum
density, except for the top twelve (12) inches which should be compacted to
95 percent of maximum density.
Soils expected to be exposed in the footing and utility excavations range from poorly
graded sand with silt to peat. In our opinion, the sands are usable as structural fill,
provided they are moisture conditioned to near optimum moisture content. In order
to moisture condition the sand, it may be necessary to either add water or aerate the
soil. However, the peat, which may be exposed in the utility trenches, is not suitable
for use as structural fill. Excavated peat should be removed from the site or used in
landscape areas.
Structural fill which is to be placed in wet weather should consist of a granular
material with a maximum size of three inches and no more than 5 percent fines
passing the No. 200 sieve, based on the minus 3/4-inch fraction. During dry weather,
most compactible non-organic soil can be used as structural fill. It is recommended
that any structural fill planned for on site use be submitted for approval prior to
import.
Surcharge Program
The surcharge program is designed to pre-consolidate the compressible fills and soil
underlying the site, such that the surcharge would apply loads near to or greater than
anticipated building loads. The surcharge fill should be a minimum of two feet in
height, measured from the finish floor elevation. The estimated time frame for the
surcharge to remain in place is four to six weeks. The actual time period will be
dependent upon the measured settlement obtained in the field. If a shorter time frame
is necessary, a thicker surcharge would be needed. The surcharge should extend at
least five feet beyond the perimeter of the buildings. The side slopes of the fill should
be inclined at a gradient of 1 H:1 V (Horizontal:Vertical) or flatter. If a wet weather
construction schedule is planned, and the surcharge fill is to be used as structural fill,
the surcharge fill should meet the requirements of structural fill to be placed in wet
weather as discussed in the Site Preparation and Grading section of this study.
Earth Consultants, Inc.
GEOTECHNICAL ENGINEERING STUDY
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August 19, 1994 Page 6
If future expansion of any building is anticipated, the surcharge should extend at least
twenty (20) feet in the direction of the future addition. The purpose of extending the
surcharge is to reduce the possibility of settlement of the then-existing building from
future building or surcharge loads.
Surcharge fill does not have to meet any specific requirements except that the
material should have an in-place unit weight of one hundred twenty (120) pounds per
cubic foot (pcf). Depending on the type of material used as surcharge material, it may
be necessary to apply compactive effort to achieve the 120 pcf unit weight criteria.
Alternatively, if a light material is used as surcharge material, a thicker surcharge
could be used in lieu of applying compactive effort. If the surcharge fill material is to
be used for structural fill in other areas after completion of the surcharge program, it
should meet the requirements for structural fill discussed previously.
The settlement induced by the surcharge fill is anticipated to be about four to six
inches. A smaller settlement than estimated would indicate that the soil conditions
with respect to consolidation are better than anticipated. Conversely, a larger
settlement than estimated would indicate the soil conditions are worse than
anticipated, and that additional time and measurements should be taken to obtain
satisfactory results.
Because the purpose of the surcharge fill is to induce settlement, it is necessary to
monitor both the magnitude and rate of such settlement. To accomplish this, we
recommend installation of settlement markers within the surcharged area. The
number of settlement markers placed will depend on the actual size of the building.
As a general rule, one settlement marker should be placed for every ten thousand to
fifteen thousand (10,000 to 15,000) square feet (sf) of floor area. More specific
details of the settlement monitoring program are presented below.
• Settlement markers should be placed on the existing subgrade of the building
pad before any fill is placed. ECI can supply and install these markers. (A
typical detail is provided on Plate 3).
• A baseline reading is obtained on each marker and is referenced to a
temporary benchmark located on a feature that will not be affected by the fill-
induced settlements.
• The fills are then placed. Settlement readings are taken at relatively short
intervals (daily) during this process, since this phase generates relatively large
and rapid settlement.
Earth Consultants, Inc.
GEOTECHNICAL ENGINEERING STUDY
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August 19, 1994 Page 7
• Once the fill operation is complete, readings are obtained on a periodic basis,
typically weekly, until the settlement ceases or the anticipated future
settlements -are judged by the geotechnical engineer to be less than
approximately one inch.
• Each set of settlement readings are plotted graphically against time to
determine the magnitude and rate of settlement, and are matched against the
predicted magnitudes and rates to verify the accuracy of earlier estimates and
to make any appropriate modifications.
ECI should be retained to acquire the settlement readings. If you prefer to use another
organization to collect these readings, measurements should be provided to us as
quickly after their acquisition as possible for plotting and interpretation. This will help
avoid any misinterpretation or misunderstanding regarding the success of the
surcharge program.
The settlement markers must be kept intact during earthwork operations. In our
experience, earthwork equipment (dozers, rollers,trucks, etc.) often demolish markers
at a very high rate. This adds to the project costs in that they need to be replaced
and it makes the information obtained less reliable. To avoid this scenario, it is
suggested that the project specifications include a requirement that the earthwork
contractor is required to immediately replace any damaged settlement marker and
have the settlement readings reobtained at his own cost. This requirement makes the
earthwork contractor more conscious of the importance of the surcharge program and
will aid in maintaining the integrity of the monitoring program.
Fill for landscaping purposes should not be placed near the building since additional
fill could induce further settlements after the building is constructed. If such fill is
planned, the surcharge should be extended to five feet beyond the planned landscape
fill, or a lightweight fill, such as "hog fuel" be used.
Foundations
Based on the encountered subsurface soil conditions, preliminary design criteria, and
assuming compliance with the preceding Site Preparation and Grading section, the
proposed structures may be supported by a minimum of two feet of structural fill.
Based on our understanding of the project, some of the foundations may bear in the
existing fill. The existing fill is considered suitable for support of foundations;
however, the fill within two feet of the bottom of footings must be compacted to the
requirements of structural fill.
Earth Consultants, Inc.
GEOTECHNICAL ENGINEERING STUDY
Trammell Crow E-3453-4
August 19, 1994 Page 8
The foundation may be designed for an allowable soil bearing capacity of two
thousand five hundred (2500) pounds per square foot (psf) when bearing on. at least
two feet of structural fill. Footings should be at least twelve (12) inches in width and
extend to a depth of at least eighteen 0 8) inches below the lowest adjacent grade.
The above allowable soil bearing value is for dead-plus-live loads and may be
increased one-third for combined dead, live, wind, and seismic forces. It is
recommended that all footing excavations be observed by a representative of ECI,
prior to placing forms or rebar, to verify that exposed soil conditions are as anticipated
in this report, and/or provide suitable modifications in the design, as required.
Without completion of the surcharge program, we estimate there is a potential for four
to six inches of total settlement with two to three inches of differential settlement.
Following successful completion of the surcharge program, total settlements are
expected to be less than one inch for foundations bearing on structural fill.
Differential settlement is anticipated to be about three-quarters of an inch.
Seismic Design Considerations
The Puget Sound region is classified as Seismic Zone 3 by the Uniform Building Code
(UBC). The largest earthquakes in the Puget Sound region have been subcrustal
events, ranging in depth from 50 to 70 kilometers. Such deep events have exhibited
no surface faulting.
The UBC earthquake regulations contain a static force procedure and a dynamic force
procedure for design base shear calculations. Based on the encountered soil
conditions, it is our opinion that a site coefficient of 1 .5 should be used for the static
force procedure, as outlined in Section 2334 of the 1991 UBC. For the dynamic force
procedure outline in Section 2335 of the 1991 UBC, the curve for Soft to Medium
Clays and Sands (Soil Type 3) should be used on Figure 23-3, Normalized Response
Spectra Shapes.
Earth Consultants, Inc.
GEOTECHNICAL ENGINEERING STUDY
Trammell Crow E-3453-4
August 19, 1994 Page 9
Liquefaction is a phenomenon in which soils lose all shear strength for short periods
of time during an earthquake. The effects of liquefaction may be large total and/or
differential settlement for structures with foundations founded in the liquefying soils.
Groundshaking of sufficient duration results in the loss of grain to grain contact and
rapid increase in pore water pressure, causing the soil to behave as a fluid for short
periods of time. To have potential for liquefaction, a soil must be cohesionless with
a grain size distribution of a specified range (generally sands and silt); it must be loose
to medium-dense; it must be below the groundwater table; and it must be subject to
sufficient magnitude and duration of groundshaking. Based on the subsurface
information obtained during our field exploration, it is our opinion that the liquefaction
potential at the site is low due to the relative density of the soils encountered and
cohesive nature of the encountered silts.
Lateral Resistance
An allowable passive pressure value against the sides of foundation slabs or other
subsurface foundation elements of three hundred (300) psf per foot of depth may be
used for design. In order to fully mobilize the passive pressure, the foundations must
be poured "neat" against the adjacent soil or the foundation excavation must be
backfilled with structural fill. Friction between the base of foundations and the
underlying soil may be assumed to be 40 percent of the dead load. The friction and
passive pressure design values include a factor of safety of 1 .5.
Retaining Walls
Retaining walls and foundation walls that will act as retaining walls should be
designed to resist lateral earth pressures imposed by the retained soils. Walls that are
designed to yield can be designed to resist the lateral earth pressure imposed by an
equivalent fluid with a unit weight of thirty-five (35) pounds per cubic foot (pcf). The
equivalent fluid weight should be increased to fifty (50) pcf for walls that are
restrained at the top from free movement. These values are based on horizontal
backfill and that surcharges due to backfill slopes, hydrostatic pressures, traffic,
structural loads or other surcharge loads will not act on walls. If such surcharges are
to apply, they should be added to the above design lateral pressures. Calculation of
lateral resistance should be done using the passive pressure and coefficient of friction
values contained in the previous section.
For earthquake loading, a rectangular pressure distribution equal to six times the wall
height should be added to the above lateral earth pressure values.
Earth Consultants, Inc.
GEOTECHNICAL ENGINEERING STUDY
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August 19, 1994 Page 10
Retaining walls should be backfilled with a free-draining material conforming to the
WSDOT specification for gravel backfill for walls (WSDOT 9-03.12(2)). The
free-draining material should extend a minimum of eighteen inches behind the wall.
The remainder of the backfill should consist of structural fill. A perforated drain pipe
should be placed at the base of the wall. Drain pipes located in the free-draining
backfill soil should be perforated with holes less than one-half inch in diameter. The
-drain pipe should be surrounded by a minimum of one cubic foot per lineal foot
with 3/4 rock or should be wrapped with a filter fabric.
Slab-on-Grade Floors
Slab-on-grade floors should be supported on a minimum of one foot of new structural
fill or recompacted existing fill. Should loose soil be present at the slab subgrade
elevation, it should be compacted to the requirements of structural fill. Any disturbed
subgrade soil must either be re-compacted or replaced with structural fill. Slab-on-
grade floors should be designed by the structural engineer based on the anticipated
loading and the subgrade support characteristics. A modulus of vertical subgrade
reaction of three hundred fifty (350) pounds per cubic inch (pci) may be used for
design.
The slab should be provided with a minimum of four inches of free-draining
g sand or
gravel. In areas where slab moisture is undesirable, a vapor barrier such as a 6-mil
plastic membrane may be placed beneath the slab. Two inches of damp sand may be
placed over the membrane for protection during construction and to aid in curing of
the concrete.
Excavations and Slopes
Excavation slopes should in no case be greater than the limits specified in local, state
and federal safety regulations. As described in the current Occupational Safety and
Health Administration (OSHA) regulations, soils anticipated to be encountered in
excavations (fill and peat) would classify as Type "C." Therefore, temporary cuts
greater than four feet in height should be sloped at an inclination no steeper than
1 .5H:1 V in the Type "C" soils. If slopes of this inclination, or flatter, cannot be
constructed, or if excavations greater than twenty (20) feet in depth are required,
temporary shoring may be necessary. This shoring would help protect against slope
or excavation collapse, and would provide protection to workmen in the excavation.
If temporary shoring is required, we will be available to provide shoring design criteria,
if requested.
Earth Consultants, Inc.
GEOTECHNICAL ENGINEERING STUDY
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August 19, 1994 Page 11
All permanent slopes should be inclined no greater than 2H:1 V. If this inclination
cannot be maintained, this office should be contacted to review the design and
construction criteria: We also recommend that all cut slopes be examined by Earth
Consultants, Inc. during excavation to verify that conditions are as anticipated.
Supplementary recommendations can then be developed, if needed, to improve the
stability, including flattening of slopes or installation of drainage. In any case, water
should not be allowed to flow uncontrolled over the top of any slopes.
The above information has been provided solely as a service to our client. Under no
circumstances should the above information be interpreted to mean that this office is
assuming responsibility for construction site safety or the contractor's activities; such
responsibility is not being implied and should not be inferred.
Site Drainage
Groundwater seepage was observed in all of the test pits except TP-5, TP-7, TP-8,
TP-11 and TP-12 at depths ranging from five and one-half (5.5) to eight and
one-half (8.5) feet below the existing ground surface. It is possible that groundwater
levels will present construction related problems while excavating the foundations or
utility trenches. Should groundwater seepage be encountered in excavations during
construction, the bottom of the excavations should be sloped to one or more shallow
sump pits. The collected water can then be pumped from these pits to a positive and
permanent discharge, such as a nearby storm drain. Depending on the magnitude of
such seepage, it may also be necessary to interconnect the sump pits by a system of
connector trenches. It is recommended that the appropriate locations of subsurface
drains, if needed, be established during grading operations by this office, at which
time the seepage areas, if present, may be more clearly defined.
The site should be graded such that surface water is directed off the site. Water
should not be allowed to stand in any area where structures, slabs or driveways are
to be constructed. During construction, loose surfaces should be sealed at night by
compacting the surface to reduce the potential for moisture infiltration into the soils.
Final site grades should allow for drainage away from the structure foundations. The
ground should be sloped at a gradient of 3 percent for a distance of at least ten feet
away from the building, except in areas that are to be paved, which can be sloped at
a gradient of 1 percent.
Foundation drains should be installed in non-dock-high areas where landscaped areas
are immediately adjacent to the building. In our opinion, foundation drains are not
necessary in areas where pavements extend to the building walls. The drains should
be installed at or just below the bottom of the footing, with a gradient sufficient to
initiate flow. A typical detail is provided on Plate 5.
Earth Consultants, Inc.
GEOTECHNICAL ENGINEERING STUDY
Trammell Crow E-3453-4
August 19, 1994 Page 12
Utility Support and Backfill
Based on the soil conditions encountered,the majority of soils expected to be exposed
by utility excavations should provide adequate support for utilities; however, deeper
utility trenches may encounter the peat that is beneath the existing fills. Should the
peat, or soft soils, be exposed near pipe grades, the peat should be removed to a
depth that will provide adequate support for the utility.
Utility trench backfill is a major concern in reducing the potential for settlement along
utility alignments, particularly in pavement areas. It is important that each section of
utility line be adequately supported in the bedding material. The material should be
hand tamped to ensure support is provided around the pipe haunches. Fill should be
carefully placed and hand tamped to about twelve (12) inches above the crown of the
pipe before any heavy compaction equipment is brought into use. The remainder of
the trench backfill should be placed in lifts having a loose thickness of less than
twelve 0 2) inches. A typical trench backfill section and compaction requirements for
load supporting and non-load supporting areas is presented on Plate 4.
Pavement Areas
The adequacy of site pavements is related in part to the condition of the underlying
subgrade. To provide a properly prepared subgrade for pavements, we recommend
the subgrade be treated and prepared as described in the Site Preparation and Grading
section of this report. This means at least the top twelve (12) inches of the
subgrade should be compacted to 95 percent of the maximum dry density (per ASTM
1557-78). It is possible that some localized areas of soft, wet or unstable subgrade
may still exist after this process. Therefore, a greater thickness of structural fill or
crushed rock may be needed to stabilize these localized areas.
We recommend the following pavement section for lightly loaded areas:
• Two inches of Asphalt Concrete (AC) over four inches of Crushed Rock Base
(CRB) material, or
• Two inches of AC over three inches of Asphalt Treated Base (ATB) material.
Heavier truck-traffic areas will require thicker sections depending upon site usage,
pavement life and site traffic. As a general rule, you may consider for truck-trafficked
areas the following sections:
• Three inches of AC over six inches of CRB, or
• Three inches of AC over four and one-half inches of ATB.
Earth Consultants, Inc.
GEOTECHNICAL ENGINEERING STUDY
Trammell Crow E-3453-4
i August 19, 1994 Page 13
Asphalt Concrete (AC), Asphalt Treated Base (ATB), and Crushed Rock Base (CRB)
materials should conform to WSDOT specifications. All rock base should be
compacted to at least 95 percent of the ASTM D-1557-78 laboratory test standard.
It should be noted that parking stall pavement sections assume no truck-traffic.
LIMITATIONS
Our recommendations and conclusions are based on the site materials observed,
selective laboratory testing and engineering analyses, the design information provided
to us by you, and our experience and engineering judgement. The conclusions and
recommendations are professional opinions derived in a manner consistent with that
level of care and skill ordinarily exercised by other members of the profession currently
practicing under similar conditions in this area. No warranty is expressed or implied.
The recommendations submitted in this report are based upon the data obtained from
the test pits. Soil and groundwater conditions between test pits may vary from those
encountered. The nature and extent of variations between our exploratory locations
may not become evident until construction. If variations do appear, ECI should be
requested to re-evaluate the recommendations of this report and to modify or verify
them in writing prior to proceeding with the construction.
Additional Services
This office will be available to provide consultation services relating to review of the
final design and specifications to verify that our recommendations have been properly
interpreted and implemented in the approved construction plans and specifications.
In addition, it is suggested that this office be retained to provide geotechnical services
during construction to observe compliance with the design concepts and project
specifications, and to facilitate design changes in the event subsurface conditions
differ from those anticipated prior to the start of construction. It should be noted that
it is generally in the best interests of the owner/client to maintain the same Soils
Engineer during construction in order to obtain the project objective, with optimum
quality control.
Earth Consultants, Inc.
14 RD
�. EeWNGTON I
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41
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T1 ( ■,r �� %,7gTHJ S
Reference:
King County / Map 41
By Thomas Brothers Maps
Dated 1990
Earth Consultants Inc. 27th Street Warehouse
Vicinity Map
Grolechnlcal F1LgIrx�P.rS,Geob$ls,s&Fsvlrorvnen,al Sck•nllsl S.W.
s
Renton, Washington
Proj. No. 3453-4 Drwn. GLS Date Aug. '94 Checked DSL Date 8/10/94 Plate 1
-i P-8 TP-6 TP-5 1
� � o
TP-9 TP-10
' TP-4
j Existing I
Tilt Up Warehouse!
DTP-12 TP-11
TP-3
! --------! TP-2
' TP-1 -DTP-13
S.W. 27th STREET I,
LEGEND
TP-1 + Approximate Location of
ECI Test Pit, Proj. No.
E-3453-4, Aug. 1994
Existing Building Approximate Scale
Proposed Building 0 100 200 400ft.
Furth Consultants Inc. Test Pit Location Plan
eot Gechnk fne al Fs$ ers,GeblogLsts&Fnvironnx-ntal Scirntlsts S.W. 27th Street Warehouse
Renton, Washington
Proj. No. 3453-4 FDrwn. GLS Date Aug. '94 lChecked DSL Date 8/10/94 Plate 2
SCHEMATIC ONLY- NOT TO SCALE
NOT A CONSTRUCTION DRAWING
Surcharge
rPr Pr
eload Surcharge
char
a rPr
elo
ad
F
Fill
Fill
Il_ 1
i —
=111
STANDARD NOTES
1) Base consists of 3/4 inch thick, 2 foot by 2 foot plywood with center drilled
5/8 inch diameter hole.
2) Bedding material, if required, should consist of Traction Sand.
3) Marker rod is 1/2 inch diameter steel rod threaded at both ends.
4) Marker rod is attached to base by nut and washer on each side of base.
5) Protective sleeve surrounding marker rod should consist of 2 inch diameter
plastic tubing. Sleeve is NOT attached to rod or base.
6) Additional sections of steel rod can be connected with threaded couplings.
7) Additional sections of plastic sleeve can be connected with press-fit plastic
couplings.
8) Steel marker rod should extend at least 6 inches above top of plastic
sleeve.
9) Marker should extend at least 2 feet above top of fill surface.
Earth Consultant IncYPICAL SETTLEMENT MARKER DETAIL
S C. S.W. 27th Street Warehouse
Cx-aextvOd FsB�rs.GrologLsts•Fllvliorvixattal SeirntLsts
Renton, Washington
Proj. No. 3453-4 Drwn. GLS Date Aug. '94 Checked DSL [Date 8/10/94 Plate 3
Non-Load Supporting Floor Slab or
Areas Roadway Areas
0�0 0
0 0 o Varies
.D
0 0
0
0
0 95 0
o
°o 0
85 �
95 1 Foot Minimum
Backfill
80 90
Varies
o O o ;`> PIPE o 0" 00.
Oo ° oo ° .. 0,Do. 0�
O,,�oe•oo 00. /� o.�;o
b•ea.00,•.0•
.0.00.Qa.•�'o;'
Bedding .•. Q.. o.,..°. °.
0.d0. .:.00'ooOoQo .o o•�oo 0 0.0.. Varies
pO• SCO
O..00O000°08.'.00.0�o..oOp••�000
QO.�°. O Oo e O° O.
�' o 'O.O OO '�••0130.
LEGEND:
ujJ}�� Asphalt or Concrete Pavement or Concrete Floor Slab
S�=;vSf���.��yF
[.0� � oee
o ° ° o • Base Material or Base Rock
Backfill; Compacted On-Site Soil or Imported Select Fill
Material as Described in the Site Preparation of the General
Earthwork Section of the Attached Report Text.
95 Minimum Percentage of Maximum Laboratory Dry Density as
Determined by ASTM Test Method D 1557-78 (Modified Proctor),
Unless Otherwise Specified in the Attached Report Text.
,.. .o Bedding Material; Material Type Depends on Type of Pipe and
Laying Conditions. Bedding Should Conform to the Manufacturers
Recommendations for the Type of Pipe Selected.
-- TYPICAL UTILITY TRENCH FILL
Earth Consultants Inc. S.W. 27th Street Warehouse
GrcNecrinical Fs AlnreR.C.mlogLsis&fnvlmnmrnr.N`i(itT�ltitS Renton, Washington
Proj. No. 3453-4 Drwn. GLS Date Aug. '94 Checked DSL TDate7/10/94 Plate 4
0
o
Slope To Drain ;
°o
ve y .o'•O
6 inch min.
•�,��� :••moo =�•� '�•4, •!��•••v.•b o 18 inch min.
4 inch min. "' _ %. •. - o 0 0_.
Diameter -
Perforated Pipe—!� :, :o.';.•:o:'::;'' - _° -°°
Wrapped in Drainage - °• -
Fabric
2 inch min. / 4 inch max.
12 inch 2 inch min.
min.
SCHEMATIC ONLY - NOT TO SCALE
NOT A CONSTRUCTION DRAWING
LEGEND
Surface seal; native soil or other low permeability material.
Fine aggregate for Portland Cement Concrete; Section 9-03.1(2) of the
WSDOT Specifications.
ODrain pipe; perforated or slotted rigid PVC pipe laid with perforations or
slots facing down;tight jointed;with a positive gradient. Do not use flexible
corrugated plastic pipe. Do not tie building downspout drains into footing
lines. Wrap with Mirafi 140 Filter Fabric or equivalent.
Earth Consultants IncYPICAL FOOTING SUBDRAIN DETAIL
C' S.W. 27th Street Warehouse
Renton, Washington
Proj. No. 3453-4 Drwn. GLS Date Aug. '94 Checked DSL Date 8/10/94 Plate 5
APPENDIX A
E-3453-4
FIELD EXPLORATION
Our test pit exploration was performed on August 3, 1994. The subsurface
conditions at the site were explored by excavating thirteen test pits to a maximum
depth of fifteen and one-half (15.5) feet below the existing ground surface. The test
pits were excavated by Evans Brothers Construction, using a rubber-tire backhoe.
The approximate test pit locations were determined by pacing from existing on site
landmarks. The locations of the test pits should be considered accurate only to the
degree implied by the method used. These approximate locations are shown on the
Test Pit Location Plan, Plate 2. The field exploration was continuously monitored by
an engineer from our firm, who classified the soils encountered and maintained a log
of each test pit, obtained representative samples, and observed pertinent site features.
All samples were visually classified in accordance with the Unified Soil Classification
System which is presented on Plate Al, Legend. Logs of the test pits are presented
on Plates A2 through A14. The final logs represent our interpretations of the field
logs and the results of the laboratory tests on field samples. The stratification lines
on the logs represent the approximate boundaries between soil types. In actuality, the
transitions may be more gradual. Representative soil samples were placed in closed
containers and returned to our laboratory for further examination and testing.
Earth Consultants, Inc.
MAJOR DIVISIONS GRAPH LETTER TYPICAL DESCRIPTION
SYMBOL SYMBOL
GraGW Well-Graded Gravels,Gravel-Sand
AndVel Clean Gravels PAo o o Q Q gW Mixtures, Little Or No Fines
Gravelly (little or no fines) M
Coarse Soils . . . Gp Poorly-Graded Gravels,Gravel-
Grained gp Sand Mixtures, Little Or No Fines
Soils More Than
50% Coarse GM Silty Gravels,Gravel-Sand-
Gravels With gm Silt Mixtures
Fraction Fines(appreciable
Retained On amount of fines) GC Clayey Gravels,Gravel-Sand-
No. 4 Sieve gC Clay Mixtures
Sand .o o� .o SW Well-Graded Sands, Gravelly
And Clean Sand o c�' o c SW Sands, Little Or No Fines
Sandy (little or no fines) ;;P:�;; :;�
More Than ::4:::;:>>':<:: SP Poorly-Graded Sands, Gravelly
Soils
I s ....
50% Material ;:: ::::;??::::>:::::> :i Sp Sands, Little Or No Fines
Larger Than More Than
No.200 Sieve 50% Coarse SM Silty Sands, Sand- Silt Mixtures
Size Fraction Sands With Sm
Fines(appreciable
Passing No.4 amount of fines) SC
Sieve Sc Clayey Sands, Sand-Clay Mixtures
ML Inorganic Silts&Very Fine Sands,Rock Flour,Silty-
ml Clayey Fine Sands;Clayey Silts w/Slight Plasticity
Fine Silts
Liquid Limit CL Inorganic Clays Of Low To Medium Plasticity,
Grained And Less Than 50 �' CI Gravelly Clays, Sandy Clays, Silty Clays, Lean
Soils Clays
I I I I I OL Organic Silts And Organic
I I I I I OI Silty Clays Of Low Plasticity
I- 1 More Than MH Inorganic Silts, Micaceous Or Diatomaceous Fire 50% Material Silts mh Sand Or Silty Soils
Smaller Than And Liquid Limit CH Inorganic Clays Of High
No.200 Sieve Clays Greater Than 50 Ch Plasticity, Fat Clays
Size
Organic Clays Of Medium To High
/ Oh Plasticity, Organic Silts
`"� `"/ —'� pTPeat, Humus, Swamp Soils
Highly Organic Soils 'Pt With High Organic Contents
Topsoil 'y y y J Humus And Duff Layer
Fill Highly Variable Constituents
The discussion in the text of this report is necessary for a proper understanding of the nature
of the material presented in the attached logs.
DUAL SYMBOLS are used to Indicate borderline soil classification.
C TORVANE READING,tsf I 2"O.D. SPLIT SPOON SAMPLER
qu PENETROMETER READING,tsf
W MOISTURE, %dry weight 24"I.D. RING OR SHELBY TUBE SAMPLER
P SAMPLER PUSHED
* SAMPLE NOT RECOVERED i WATER OBSERVATION WELL
pcf DRY DENSITY,lbs. per cubic ft.
LL LIQUID LIMIT, % Q DEPTH OF ENCOUNTERED GROUNDWATER
PI PLASTIC INDEX DURING EXCAVATION
t SUBSEQUENT GROUNDWATER LEVEL W/DATE
Earth Consultants Inc. LEGEND
Ik li—I1:11911 kx!rs.OXA)6WS 1411Winxillk-11tal Sckf1111S1S
EProj. .3453-4 Date Aug'94 Plate Al
Test Pit Log
Project Name: Sh:eet::of
S.W. 27TH Street Warehouse 1
Job No. Logged by: Date: Test Pit No.:
3453-4 DSL 8 3 94 TP-1
Excavation Contactor: Ground Surface Elevation:
Evans Brothers Construction f
Notes:
W = o } o Surface Conditions: Grass
a_ a � a Un
M ro T N � ro T
cD U cn rn
SM FILL- Brown silty fine to coarse SAND with gravel,medium dense,moist
1
2 SP-SM FILL- Brown poorly graded medium to coarse SAND with silt and gravel,medium dense
4.4
3
4 FILL- Gray poorly graded medium to coarse SAND with silt
15.6
5
6
-slight caving
7
— 8 very minor seepage
PEAT Dark brown fibrous PEAT interbedded with organic silt,soft to medium stiff,wet to
—`' saturated
91.1 u Lt 9
L .�
10
11 ML Gray SILT,soft to medium stiff,saturated
46.1
12
13
14 Test pit terminated at 14 feet below existing grade. Very minor groundwater seepage
encountered at 8 feet during excavation.
o.
a
Go
Test Pit Log
"' Earth Consultants Inc. S.W. 27TH Street Warehouse
ceo�nnoneem aeoioQ ►s .,u saena"
Renton, Washington
(L Proj.No. 3453-4 Dwn. GLS Date Aug'94 Checked DSL Date 8/17/94 Plate A2
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,
analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or
interpretation by others of information presented on this log.
Test Pit Log
Project Name: Sheet of
S.W. 27TH Street Warehouse 1 1
Job No. Logged by: Date: Test Pit No.:
3453-4 1 DSL 8 3 94 TP-2
Excavation Contactor: Ground Surface Elevation:
Evans Brothers Construction f
Notes:
U _
W L o } N o Surface Conditions: Grass
%� m aai u` ro M T
SP-SM FILL-Brown poorly graded medium to coarse SAND with silt and gravel,medium dense,
moist
1
4.7 2
3
4
13.6 5
6
7
-minor seepage
8 PEAT Dark brown fibrous PEAT interbedded with organic silt,soft to medium
108.2 +' `—' stiff,wet to saturated
u t0/ 9
10
11
12 ML Gray SILT,soft to medium stiff,saturated
51.2 13
14
15
Test pit terminated at 15 feet below existing grade. Minor groundwater seepage
encountered at 7.5 feet during excavation.
a
O.
CO
(1) Test Pit Log
Earth Consultants inc. S.W. 27TH Street Warehouse
Renton, Washington
J
IL Proj.No. 3453-4 Dwn. GLS Date Aug'94 Checked DSL Date 8/17/94 Plate A3
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,
analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or
interpretation by others of information presented on this log.
Test Pit Log
Project Name: Sheet of
S.W. 27TH Street Warehouse 1 1
Job No. Logged by: Date: Test Pit No.:
3453-4 DSL 8 3 94 TP-3
Excavation Contactor: Ground Surface Elevation:
Evans Brothers Construction f
Notes:
U _
W r O + v (no Surface Conditions: Grass
%) L T a) tL ro � T
c9 U 07 U
SP-SM FILL- Brown poorly graded medium to coarse SAND with silt and gravel,medium
dense,damp
1
4.1 2
3
4
10.4
5 -becomes wet to saturated
6 FILL: Gray poorly graded medium to coarse SAND with silt
7
-very minor seepage
PEAT Dark brown fibrous PEAT interbedded with organic silt,soft to medium stiff,wet to
—` 8 saturated
100.3 u Lc
10
12 MH Gray elastic SILT,soft to medium stiff,wet to saturated
qu=1.Qtsf
13
qu=o.25tsf 56.4
14
31.9 SP-SM Black poorly graded fine SAND with silt,loose to medium dense,water bearing
15
Test pit terminated at 15 feet below existing grade. Very minor groundwater seepage
encountered at 7.5 feet during excavation
�t
o1
o.
m
Test Pit Log
Earth Consultants Inc. S.W. 27TH Street Warehouse
Renton, Washington
CL J
Proi.No. 3453 4 Dwn. GLS Date AUg'94 Checked DSL Date 8/17/94 Plate A4
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,
analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or
interpretation by others of information presented on this log.
Test Pit Log
Project Name: Sheet of
S.W. 27TH Street Warehouse 1 1
Job No. Logged by: Date: Test Pit No.:
3453-4 DSL g 3 94 TPA
Excavation Contactor: Ground Surface Elevation:
Evans Brothers Construction f
Notes:
U _
W .L o + N Surface Conditions: Grass
LM °' v_ ro � T
L C O U) U)
SP-SM FILL:- Gray poorly graded medium to coarse SAND with silt and gravel,damp
1
4.5 2
3
4
5
-becomes wet to saturated
7.2 6 -moderate seepage
FILL:- Gray poorly graded GRAVEL with sand
7 severe caving
PEAT Brown fibrous PEAT,soft to medium stiff,saturated
120.3
8 Test pit terminated at 8 feet below existing
grade due to caving. Moderate groundwater
seepage encountered at 6 feet during excavation.
v
0%
o.
CO
Test Pit Log
�'
CI) Earth Consultants Inc.
S.W. 27TH Street Warehouse
`t ceaa�rcat a��aedo�wu a emw.,,a,�a sacaw
Renton, Washington
J
Proj.No. 3453 4 Dwn. GLS Date Aug'94 Checked DSL Date 8/17/94 Plate A5
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,
analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or
interpretation by others of information presented on this log.
Test Pit Log
-T --
Project Name: Sheet of
S.W. 27TH Street Warehouse 1 1
Job No. Logged by: Date: Test Pit No.:
j 3453-4 DSL 8 3 94 TP-5
Excavation Contactor: Ground Surface Elevation:
Evans Brothers Construction f
Notes:
U _
W U o U) o Surface Conditions: Grass and Scot's Broom
%j ru T N LL ro T
cL U) U)
SP-SM FILL.• Brown poorly grade fine to medium SAND with silt and gravel,loose to medium
dense,damp to moist
1
2.0
2
3
4
5
6
7
8
9.1
9
10 PEAT Brown fibrous PEAT interbedded with organic silt,soft to medium stiff,wet to saturated
71.8 L
11
12
13
011 111,
43.6 14 MH Gray elastic SILT,very soft to soft,wet to saturated.
q u=.25tsf
15
Test pit terminated at 15 feet below existing grade. No groundwater seepage
encountered during excavation.
a
o.
of
Test Pit Log
`nI`fh Consultants inc.
S.W. 27TH Street Warehouse
Sot n
ceo+eaIIuca� \�ec�ceok¢� a srm n..a as Cl) Renton, Washington
J
Proj.No. 3453 4 Dwn. GLS Date Aug'94 Checked DSL Date 8/117/94 Plate A6
S,jbsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,
analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or
interpretation by others of information presented on this log.
Test Pit Log
Project Name: Sheet of
S.W. 27TH Street Warehouse 1 1
Job No. Logged by: Date: Test Pit No.:
3453-4 DSL 8 3 94 TP-6
Excavation Contactor: Ground Surface Elevation:
Evans Brothers Construction
Notes:
U _
W L o } 0! o Surface Conditions: Grass
SP-SM FILL- Brown poorly graded SAND with silt and gravel,loose,damp
1
2.5
2 -becomes medium dense
3
4
5
FILL Gray poorly graded SAND with silt
6
8.9 7
g seepage
-minor a e
„ Brown fibrous PEAT with interbedded organic silt,soft to medium stiff,wet to saturated
10
216.2 L, r
11
MH Gray elastic SILT,medium stiff to stiff,saturated
qu=1.25tsf 12
78.4
13
14
15
Test pit terminated at 15 feet below existing grade. Minor groundwater seepage
encountered at 8.5 feet during excavation.
v
ON
\
o.
00
Test Pit Log
in Earth Consultants Inc.
u' S.W. 27TH Street Warehouse
`r GOO*Chn"nnone&&ceoio a a �aeae.>bma
Renton, Washington
CL J
Proi.No. 3453 4 Dwn. GLS Date Aug'94 Checked DSL Date 8/17/94 Plate A7
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,
analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or
interpretation by others of information presented on this log.
Test Pit Log
Project Name: Sheet of
S.W. 27TH Street Warehouse 1 1
Job No. Logged by: Date: Test Pit No.:
3453-4 DSL 8 3 94 TP-7
Excavation Contactor: Ground Surface Elevation:
Evans Brothers Construction f
Notes:
U _
W t o t v 0 Surface Conditions: Grass
a-0 a a � n
M (aT vL ro U) T
(; O
SP-SM FILL• Brown poorly graded SAND with silt and gravel,loose to medium dense,damp to
moist
1
7.3 2
3
F1LL• Gray poorly graded SAND with silt
4
5
6
7
8 PEAT Dark brown fibrous/woody PEAT with interbedded organic silt,soft to medium stiff,wet
f to saturated
117.1 u u 9
L0', .
10
11
MH 12 Dark gray elastic SILT,medium stiff,wet to saturated
qu=.51.25tsf 58.6
13 -peat stringers
14
15 Test pit terminated at 15 feet below existing grade. No groundwater seepage
encountered during excavation.
v
a
a
CC)
cv) Test Pit Log
Earth Consultants Inc. S.W. 27TH Street Warehouse
`i ceaear+w$ng eat,OW0064 a e:M,O n.or"eacriw
r' Renton, Washington
J
Proj.No. 3453-4 Dwn. GLS Date AUg'94 Checked DSL Date 8/17/94 Plate A8
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,
analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or
interpretation by others of information presented on this log.
Test Pit Log
Project Name: Sheet of
S.W. 27TH Street Warehouse 1 1
Job No. Logged by: ��8/3/94
te: Test Pit No.:
3453-4 DSL TP-8
Excavation Contactor: Ground Surface Elevation:
Evans Brothers Construction f
Notes:
U _
W = o + o Surface Conditions: Grass
(D U)
SM FILL. Brown silty SAND with gravel,loose to medium dense,damp to moist
1
2 SP-SM FILL- Gray poorly graded SAND with silt,wet
6.7
3
4
5
6 PEAT Brown fibrous/woody PEAT interbedded with organic silt,soft to medium stiff,wet to
saturated
113.8 ti!, 7
L
L .!r, .
9
0/ 4 r/
10 OL Gray organic SILT,very soft to soft,saturated
qu<.5tsf I I I I
I I
78.6 I I 11
IIII
12
IIII
I I
IIII
I I I I 13
IIII
IIII
14
IIII
I I 15
Test pit terminated at 15 feet below existing grade. No groundwater seepage
encountered during excavation.
v
a
a
w
0 Test Pit Log
Ln Cl) Earth Consultants Inc. S.W. 27TH Street Warehouse
`r ceoaea�w�� a envi sae es
"' Renton, Washington
Proj.No. 3453-4 Dwn. GLS Date Aug'94 Checked DSL Date 8/17/94 Plate A9
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,
analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or
interpretation by others of information presented on this log.
Test Pit Log
Project Name: Sheet of
S.W. 27TH Street Warehouse 1 1
Job No. Logged by: Date: Test Pit No.:
3453-4 DSL 8 3 94 TP-9
Excavation Contactor: Ground Surface Elevation:
Evans Brothers Construction f
Notes:
W 0 _q o Surface Conditions: Grass
%) L o fn
t N
SM fill: Brown silty SANd with gravel,dense,moist
1
SP-SM FILL- Gray poorly graded SAND with silt,medium dense,moist
5.5 2
3
4
11.0 5
-becomes wet
6
7
8
NfH -minor seepage
9 Gray elastic SILT,soft to medium stiff,wet to saturated
qu=.75tsf -peat interbeds
54.4 10
qu<.5tsf 11
12
13
-grades to gray sandy silt
37.9 14
qu=.75tsf
qu=l.Qtsf 46.4 15
Test pit terminated at 15.5 feet below existing grade. Minor groundwater seepage
encountered at 8.5 feet during excavation.
o.
G\
OD
Cl) Test Pit Log
Ln Earth Consultants Inc.
Via = S.W. 27TH Street Warehouse
Renton, Washington
�
Proj. No. 3453 4 Dwn. GLS Date Aug'94 Checked DSL Date 8/17/94 Plate A10
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,
analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or
interpretation by others of information presented on this log.
Test Pit Log
Project Name: Sheet of
S.W. 27TH Street Warehouse 1 1
Job No. Logged by: Date: Test Pit No.:
3453-4 DSL 8 3 94 TP-10
Excavation Contactor: Ground Surface Elevation:
Evans Brothers Construction f
Notes:
U _
W o } v o Surface Conditions: Grass
(%) L 0 cn � at
SM FILL: Brown silty SAND with gravel,medium dense,damp
1
2.0 2 SP-SM F1L - Brown poorly graded SAND with silt and gravel,medium dense,damp
3
FILL• Gray poorly graded SAND with silt
4
13.8 5
= PEAT -becomes loose,severe caving,minor seepage
6 Brown fibrous peat interbedded with organic silt,very soft to soft,saturated
7 Test pit terminated at 7 feet below existing grade due to caving. Minor groundwater
seepage encountered at 5.5 feet during excavation.
o.
a
00
`n Earth Consultants Inc, Test Pit Log
S.W. 27TH Street Warehouse
� �$�� � Renton, Washington
CL
Proj.No. 3453-4 Dwn. GLS Date Aug'94 Checked DSL Date 8/17/94 Plate A11
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,
analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or
interpretation by others of information presented on this log.
Test Pit Log
Project Name: Sheet of
S.W. 27TH Street Warehouse 1 1
Job No. Logged by: Date: Test Pit No.:
3453-4 DSL 8 3 94 TP-11
Excavation Contactor: Ground Surface Elevation:
Evans Brothers Construction f
Notes:
U
W o C o Surface Conditions: Grass
(D U)
SM FILL: Brown silty SAND with gravel,medium dense,damp
1
SP-SM FILL- Gray poorly graded SAND with silt,medium dense,damp
2.9 2
3
4
5
6
—' = 7 PEAT Brown fibrous PEAT,very soft to soft,wet to saturated
L .1r, .
83.0 L"1 u 8
-interbedded with organic silt
9
10 ML Gray SILT,soft to medium stiff
qu=1.Otsf 42.9 11
12
13
qu<.5tsf
33.6 14 SM Black silty fine SAND,loose to medium dense,water bearing
15
Test pit terminated at 15 feet below existing grade. No groundwater seepage
encountered during excavation.
v
ON
o.
00
Test Pit Log
�"' F,w`tY] C0nSL11taI1tS Inc. S.W. 27TH Street Warehouse
Renton, Washington
J
Proj.No. 3453 4 1 Dwn. GLS Date Aug'94 Checked DSL Date 8/17/94 Plate Al2
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,
analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or
interpretation by others of information presented on this log.
Test Pit Log
Project Name: Sheet of
S.W. 27TH Street Warehouse 1 1
Job No. Logged by: Date: Test Pit No.:
3453 4 DSL 8 3 94 TP-12
Excavation Contactor: Ground Surface Elevation:
Evans Brothers Construction
Notes:
W .0 o } 01 o Surface Conditions: Alder and Grass
(L.0 a� a- U �
%> Tom M � T
SM FILL: Brown silty SAND with gravel,loose,damp
1
SP-SM FILL- Brown poorly graded SAND with silt,gravel,loose,damp
3.0 2
3
4 -becomes wet
5
FILL- Gray poorly graded SAND with silt
11.2 6
7
— 8
PEAT Interbedded brown fibrous PEAT and organic silt,very soft to soft,wet to saturated
58.3 ', .'�, 9
10
\Q/ \1+i
106.3 11
45.2 12 ML Gray SILT,medium stiff to stiff,saturated
q u=1.0tsf
13
14 Test pit terminated at 14 feet below existing grade. No groundwater seepage
encountered during excavation.
lzt
D,
a
cc
Test Pit Log
to Earth Consultants Inc. S.W. 27TH Street Warehouse
� ceob«���eas,ceoa�an a e ,e�eaernats
Renton, Washington
J
� Proj. No. 3453 4 Dwn. GLS Date Aug'94 Checked DSL I Date 8/17/94 Plate A13
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,
analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or
interpretation by others of information presented on this log.
Test Pit Log
Project Name: Sheet of
S.W. 27TH Street Warehouse 1 1
Job No. Logged by: Date: Test Pit No.:
3453-4 DSL 8 3 94 TP-13
Excavation Contactor: Ground Surface Elevation:
Evans Brothers Construction f
Notes:
U
W L o + v U) o Surface Conditions: Grass
(D U N U)
SM FILL: Brown silty SAND with gravel,medium dense,damp
1 SP-SM FILL- Brown poorly graded SAND with silt and gravel,medium dense,damp
3.9 2
3
4 -becomes wet
5 FILL- Gray poorly graded SAND with silt
10.1
6
7
— 8
45.8 = PST -minor seepage
ti r, 9 Brown fibrous/woody PEAT interbedded with organic silt,very soft to soft,saturated
102.3 +. 0, 10
11 MH Gray elastic SILT,soft to medium stiff,saturated
43.3
qu=1.25-1.5tsf 12
48.5 13
qu<.5tsf
14 Test pit terminated at 14 feet below existing grade. Minor groundwater seepage
encountered at 8.5 feet during excavation.
v
0.
0.
au Test Pit Log
�' h COriSl�lfalltS IY1C. S.W. 27TH Street Warehouse
` coouu ri w emeama sae�+wa
Cl)) Renton, Washington
J
Proj. No. 3453-4 Dwn. GLS Date Aug'94 Checked DSL Date 8/17/94 Plate Al
Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests,
analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or
interpretation by others of information presented on this log.
APPENDIX B
E-3453-4
LABORATORY TEST RESULTS
Earth Consultants, Inc.
SIEVE ANALYSIS
■ ■ ■ •
09 • •• • •
�'� • •
MINE mmomm��
dm ME
IMMEMEM
MENNEN
rn
txj
�����■��■fit ���■�����■�■�■■����■■■■■����
•
• ®®
..
® • . . • S®�® DESCRIPTION
•' mm
•
t3j gray poorly graded SAND with silt
100
80
ix 60
0
z
� CH
U
40 `�--A-Line
Q
J
C �
20
& 0
CL-ML
v'
0 20 40 60 80 100
LIQUID LIMIT
Natural
Key Boring/ Depth Soil Classification USCS L.L. P.L. P I. Water
Test Pit (ft) Content
TP-1 11.5 gray SILT ML 40 31 9 46.1
TP-9 10.0 gray elastic SILT MH 68 43 25 54.4
with organics
Atterberg Limits Test Data
Earth Consultants Inc. SOUTHWEST 27TH STREET WAREHOUSE
RENTON, WASHINGTON
GmechnIcal Fngl t rs,Geologksts 6 FnAronrnental Scientists
Proj. N03453- Date 8/17/94 Plate s2
DISTRIBUTION
E-3453-4
4 Copies Trammell Crow Company
5601 Sixth Avenue South
P. O. Box 80326
Seattle, Washington 98108
Attention: Mr. Todd Timberlake
1 Copy Foushee and Associates
3260 - 118th Avenue Southeast, Suite 1000
P. O. Box 3767 (98009)
Bellevue, Washington 98005
Attention: Mr. Loch Anderson
1 Copy Lance Mueller and Associates
130 Lakeside Avenue, Suite F
Seattle, Washington 98122
Attention: Mr. Lance Mueller
Earth Consultants, Inc.
IMPORTANT INFORMATION
ABOUT YOUR
GEOTECHNICAL ENGINEERING REPORT
More construction problems are caused by site subsur- technical engineers who then render an opinion about
face conditions than any other factor. As troublesome as overall subsurface conditions, their likely reaction to
subsurface problems can be, their frequency and extent proposed construction activity, and appropriate founda-
have been lessened considerably in recent years, due in tion design. Even under optimal circumstances actual
large measure to programs and publications of ASFE/ conditions may differ from those inferred to exist,
The Association of Engineering Firms Practicing in because no geotechnical engineer, no matter how
the Geosciences. qualified,and no subsurface exploration program, no
matter how comprehensive, can reveal what is hidden by
The following suggestions and observations are offered
to help you reduce the geotechnical-related delays, earth, rock and time. The actual interface between mate-
cost-overruns and other costly headaches that can vials may be far more gradual or abrupt than a report
occur during a construction project. indicates. Actual conditions in areas not sampled may
differ from predictions. Nothing can be done to prevent the
unanticipated, but steps can be taken to help minimize their
A GEOTECHNICAL ENGINEERING impact. For this reason, most experienced owners retain their
REPORT IS BASED ON A UNIQUE SET geotechnical consultants through the construction stage, to iden-
tify variances,conduct additional tests which may be
OF PROJECT-SPECIFIC FACTORS needed,and to recommend solutions to problems
encountered on site.
A geotechnical engineering report is based on a subsur-
face exploration plan designed to incorporate a unique SUBSURFACE CONDITIONS
set of project-specific factors. These typically include:
the general nature of the structure involved, its size and CAN CHANGE
configuration: the location of the structure on the site
and its orientation; physical concomitants such as Subsurface conditions may be modified by constantly-
access roads, parking lots, and underground utilities, changing natural forces. Because a geotechnical engi-
and the level of additional risk which the client assumed veering report is based on conditions which existed at
by virtue of limitations imposed upon the exploratory the time of subsurface exploration, construction decisions
program. To help avoid costly problems, consult the should not be based on a geotechnical engineering report whose
geotechnical engineer to determine how any factors adequacy may Have been affected by time. Speak with the geo-
which change subsequent to the date of the report may technical consultant to learn if additional tests are
affect its recommendations. advisable before construction starts.
Unless your consulting geotechnical engineer indicates Construction operations at or adjacent to the site and
otherwise. your geotechnical engineering report should not natural events such as floods,earthquakes or ground-
otherwise. fluctuations may also affect subsurface conditions
be used:
• When the nature of the proposed structure is and, thus, the continuing adequacy of a geotechnical
changed, for example, if an office building will be report. The geotechnical engineer should be kept
erected instead of a parking garage, or if a refriger- apprised of any such events, and should be consulted to
ated warehouse will be built instead of an unre- determine if additional tests are necessary.
frigerated one;
.when the size or configuration of the proposed GEOTECHNICAL SERVICES ARE
structure is altered: PERFORMED FOR SPECIFIC PURPOSES
.when the location or orientation of the proposed AND PERSONS
structure is modified;
.when there is a change of ownership. or Geotechnical engineers' reports are prepared to meet
. for application to an adjacent site. the specific needs of specific individuals.A report pre-
Geotechnical engineers cannot accept responsibility for problems pared for a consulting civil engineer may not be ade-
which may develop if they are not consulted after factors consid- quate for a construction contractor, or even some other
ered in their report's development have changed. consulting civil engineer. Unless indicated otherwise,
this report was prepared expressly for the client involved
and expressly for purposes indicated by the client. Use
MOST GEOTECHNICAL "FINDINGS" by any other persons for any purpose, or by the client
r ARE PROFESSIONAL ESTIMATES for a different purpose, may result in problems. No indi-
vidual other than the client should apply this report for its
Site exploration identifies actual subsurface conditions intended purpose without first conferring with the geotechnical
only at those points where samples are taken,when engineer. No person should apply this report for any purpose
they are taken. Data derived through sampling and sub- other than that originally contemplated without first conferring
jts sequent laboratory testing are extrapolated by geo- with the geotechnical engineer.
.y
A GEOTECHNICAL ENGINEERING der the mistaken impression that simply disclaiming re-
REPORT IS SUBJECT TO sponsibility for the accuracy of subsurface information
always insulates them from attendant liability. Providing
MISINTERPRETATION the best available information to contractors helps pre-
Costly problems can occur when other design profes- vent costly construction problems and the adversarial
sionals develop their plans based on misinterpretations attitudes which aggravate them to disproportionate
of a geotechnical engineering report. To help avoid scale.
these problems, the geotechnical engineer should be READ RESPONSIBILITY
retained to work with other appropriate design profes-
sionals to explain relevant geotechnical findings and to CLAUSES CLOSELY
review the adequacy of their plans and specifications
relative to geotechnical issues. Because geotechnical engineering is based extensively
on judgment and opinion, it is far less exact than other
design disciplines. This situation has resulted in wholly
unwarranted claims being lodged against geotechnical
BORING LOGS SHOULD NOT BE consultants. To help prevent this problem, geotechnical
engineers have developed model clauses for use in writ-
SEPARATED FROM THE ten transmittals. These are not exculpatory clauses
ENGINEERING REPORT designed to foist geotechnical engineers' liabilities onto
someone else. Rather, they are definitive clauses which
Final boring logs are developed by geotechnical engi- identify where geotechnical engineers' responsibilities
neers based upon their interpretation of field logs begin and end. Their use helps all parties involved rec-
(assembled by site personnel)and laboratory evaluation ognize their individual responsibilities and take appro-
of field samples. Only final boring logs customarily are priate action. Some of these definitive clauses are likely
included in geotechnical engineering reports. These logs to appear in your geotechnical engineering report,and
should not under any circumstances be redrawn for inclusion in you are encouraged to read them closely. Your geo-
architectural or other design drawings, because drafters technical engineer will be pleased to give full and frank
may commit errors or omissions in the transfer process. answers to your questions.
Although photographic reproduction eliminates this
problem, it does nothing to minimize the possibility of OTHER STEPS YOU CAN TAKE TO
contractors misinterpreting the logs during bid prepara-
tion. when this occurs, delays, disputes and unantici- REDUCE RISK
pated costs are the all-too-frequent result. Your consulting geotechnical engineer will be pleased to
To minimize the likelihood of boring log misinterpreta- discuss other techniques which can be employed to mit-
tion, give contractors ready access to the complete geotechnical igate risk. In addition,ASFE has developed a variety of
engineering report prepared or authorized for their use. materials which may be beneficial.Contact ASFE for a
Those who do not provide such access may proceed un- complimentary copy of its publications directory.
Published by
THE ASSOCIATION
A F OF ENGINEERING FIRMS
PRACTICING IN THE GEOSCIENCES
8811 Colesville Road/Suite G 106/Silver Spring, Maryland 20910/(301) 565-2733 ,
0788/3M