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Associated Earth Sciences, Inc.
Subsurface Exploration and
Geotechnical Engineering Report
LINDBERGH HIGH SCHOOL
ATHLETIC FIELD IMPROVEMENTS
Renton, Washington
Prepared for
D.A. Hogan & Associates, Inc.
Project No. KE000669B
January 28, 2009
Associated Earth Sciences, Inc.
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January 28, 2009
Project No. KE000669B
D.A. Hogan & Associates, Inc.
119 1' Avenue South, Suite 110
Seattle, Washington 98104
Attention: Mr. Eric Gold
Subject: Subsurface Exploration and
Geotechnical Engineering Report
Lindbergh High School Athletic Field Improvements
Renton, Washington
Dear Mr. Gold:
Associated Earth Sciences, Inc. (AESI) is pleased to present the enclosed copies of our
geotechnical report. This report summarizes the results of our subsurface exploration and
geotechnical engineering study and offers geotechnical recommendations for the design and
development of the proposed project.
We have enjoyed working with you on this study and are confident that the recommendations
presented in this report will aid in the successful completion of your project. Please contact us
if you have any questions or if we can be of additional help to you.
Sincerely,
ASSOCIATED EARTH SCIENCES, INC.
Kirkland, Washington
7
Kurt D. Merriman, 7-F.-
Principal Engineer
KDMISd
KE00066982
Projects1200006691KE1W P
Kirkland Everett Tacoma
425-827-7701 425-259-0522 253-722-2992
www.aesgeo.com
GEOTECHNICAL ENGINEERING REPORT
LINDBERGH HIGH SCHOOL
ATHLETIC FIELD IMPROVEMENTS
Renton, Washington
Prepared for:
D.A. Hogan & Associates, Inc.
119 1' Avenue South, Suite 110
Seattle, Washington 98104
Prepared by:
Associated Earth Sciences, Inc.
911 5`h Avenue, Suite 100
Kirkland, Washington 98033
425-827-7701
Fax: 425-827-5424
January 28, 2009
Project No. KE000669B
Subsurface Exploration and
Lindbergh High School Athletic Field Improvements Geotechnical Engineering Report
Renton, Washington Project and Site Conditions
I. PROJECT AND SITE CONDITIONS
1.0 INTRODUCTION
This report presents the results of our subsurface exploration and geotechnical engineering
study for the proposed Lindbergh High School athletic field improvements in Renton,
Washington, Figure 1. The existing site features, topography, and the approximate locations
of the subsurface explorations referenced in this study are presented on the "Site and
Exploration Plan" (Figure 2). In the event that any changes in the nature, design, or layout of
the project are planned, the conclusions and recommendations contained in this report should
be reviewed and modified, or verified, as necessary.
1.1 Purpose and Scoff
The purpose of this study was to provide subsurface soil and shallow ground water data to be
utilized in the design and development of the proposed Lindbergh High School athletic field
improvements. Our study included a review of available geologic literature, completing eight
hollow -stem auger soil borings, and performing geologic studies to assess the type, thickness,
distribution, and physical properties of the subsurface sediments and shallow ground water. A
geotechnical engineering study was completed to determine geotechnical recommendations
regarding site' preparation, structural fill, synthetic turf subgrade preparation, general
recommendations for site drainage design, and pier foundation design recommendations for
new field lights. This report summarizes our current fieldwork and applicable fieldwork
performed for earlier studies completed on the Lindbergh High School campus in 2000 and
2002, and offers development recommendations based on our present understanding of the
project.
1.2 Authorization
Our study was accomplished in general accordance with our proposal dated December 10,
2008. We were provided with written authorization to proceed in the form of a signed copy of
our proposal. This report has been prepared for the exclusive use of D.A. Hogan &
Associates, Inc. (D.A. Hogan), the Renton School District, and their agents for specific
application to this project. Within the limitations of scope, schedule, and budget, our services
have been performed in accordance with generally accepted geotechnical engineering and
engineering geology practices in effect in this area at the time our report was prepared. No
other warranty, express or implied, is made. Our observations, findings, and opinions are a
means to identify and reduce the inherent risks to the owner.
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Renton, Washington Project and Site Conditions
2.0 PROJECT AND SITE DESCRIPTION
The project site is that of the existing Lindbergh High School lower athletic field. The project
will consist of converting the existing grass football field and cinder track to a synthetic turf
field and rubber track with new lights. We anticipate that the new improvements will be
constructed close to existing grades, with cuts and fills generally less than 2 feet to reach
subgrade elevation for the new synthetic field. A renovated natural turf field is also planned
for the existing soccer field located to the east of the football field. Other improvements
associated with this field will be new shot put, javelin, and discus areas, and a new pathway to
connect to the existing school facility. A vegetated slope separates the two field areas.
The project site is flat in the field and track areas. Moderate slopes ascend from the sides of
the track up to the east and west. These slopes are on the order of 10 to 20 feet high, inclined
at roughly 10 to 25 percent. The general site vicinity slopes down toward the east. The lower
athletic field is bounded by the upper athletic field to the northeast, the main campus to the
northwest, a community center pool to the southwest, and residential properties to the
southeast.
3.0 SITE EXPLORATION
We completed eight hollow -stem auger borings within the football track and field area at the
locations shown on Figure 2. Figure 2 also shows the locations of two borings we completed
in 2000 near the north end of the eastern field. The borings were completed by advancing a
4'/4-inch, inside -diameter, hollow -stem auger with a track -mounted drill rig. During the
drilling process, samples were obtained at generally 2.5- to 5-foot-depth intervals. The
exploration borings were continuously observed and logged by a geotechnical engineer from
our firm. The various types of soils, as well as the depths where characteristics of the soils
changed, are indicated on the exploration logs presented in the Appendix of this report. The
exploration logs presented in the Appendix are based on the field logs, drilling action, and
inspection of the samples secured. Our explorations were approximately located by measuring
from known site features shown on an aerial photograph with a preliminary site layout drawing
overlain on the photograph prepared by D.A. Hogan. Because of the nature of exploratory
work, extrapolation of subsurface conditions between field explorations is necessary. Differing
subsurface conditions may be present due to the random nature of natural sediment deposition
and the alteration of topography by past grading and filling. The nature and extent of any
variations between the field explorations may not become fully evident until construction. If
variations are observed at the time of construction, it may be necessary to re-evaluate specific
recommendations in this report and make appropriate changes.
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Disturbed, but representative samples were obtained by using the modified Standard
Penetration Test procedure. This test and sampling method consists of driving a 2-inch,
outside -diameter, split -barrel sampler a distance of 18 inches into the soil with a 140-pound
hammer free -falling a distance of 30 inches. The number of blows for each 6-inch interval is
recorded, and the number of blows required to drive the sampler the final 12 inches is known
as the Standard Penetration Resistance ("N") or blow count. If a total of 50 is recorded within
one 6-inch interval, the blow count is recorded as the number of blows for the corresponding
number of inches of penetration. The resistance, or N-value, provides a measure of the
relative density of granular soils or the relative consistency of cohesive soils; these values are
plotted on the attached exploration boring logs.
The samples obtained from the split -barrel samplers were classified in the field and
representative portions placed in watertight containers. The samples were then transported to
our laboratory for further visual classification and laboratory testing, as necessary.
4.0 SUBSURFACE CONDITIONS
Subsurface conditions on the project site were inferred from the field explorations conducted
for this and our previous studies, visual reconnaissance of the site, and a review of applicable
geologic literature. As shown on the field logs, a general sequence of fill overlying dense to
very dense Vashon lodgment till was encountered throughout the study area. Fill depths and
consistencies varied significantly across the site. The encountered soils were consistent with
the geology mapped in the site area on the Geologic Map of King County, Washington, by
Booth et al., 2006. The following section presents more detailed subsurface information
beginning from the youngest (shallowest) to oldest (deepest) sediment types.
4.1 Stratigraphy
Sod and Topsoil
Each of the borings encountered a surficial layer of snow-covered sod and topsoil.
Fill
All of the exploration borings encountered existing fill up to approximately 10 feet thick except
for B-6 (2000), which was completed on the vegetated slope that separates the two field areas.
It appears likely that the football field area was used for disposal of topsoil and excess soil that
were generated during initial development of the school site. The existing fill varies in
density, gradation, and organic content. The existing fill will present some challenges that are
addressed in greater detail later in this report. Excavated existing fill material should be
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Renton, Washington Project and Site Conditions
suitable for reuse in structural fill applications if those portions that contain excessive organic
content are segregated prior to placement in structural fill and the soils can be properly
moisture -conditioned.
Till
Natural soils beneath the fill or topsoil in B-6 consisted of glacially consolidated till. The
upper horizon of the till, interpreted as weathered till, consisted of medium dense, moist, gray -
brown, silty sand with gravel. With increasing depth, these materials typically became denser.
Unweathered till was encountered below the weathered till. The unweathered till consists of
very dense, moist to wet, gray, silty fine to coarse sand with gravel and cobbles. Either
medium dense weathered or unweathered till was encountered at depths generally ranging from
3.5 to 10 feet in our exploration borings within the athletic fields. Several thousand feet of ice
consolidated this material during the last glacial advance. This process resulted in a compact
soil possessing high -strength, low -compressibility, and low -permeability characteristics. The
medium dense to very dense till soils are suitable for light pole pier foundation support.
4.2 Laboratory Testing
We submitted three samples of the proposed football field subgrade material to our laboratory
for mechanical grain -size analysis testing in accordance with American Society for Testing and
Materials (ASTM):D 422 and ASTM:D 1140. The results of the laboratory analyses are
c6ntained in the Appendix. In general, the grain -size analyses indicated that the material
collected from a depth of about 2.5 to 4 feet below the football field contains greater than
17 percent silt. Therefore existing soils are expected to have low permeability and to be highly
moisture -sensitive.
4.3 Hydrology
Saturated surface soils and prolific perched ground water seepage was encountered in all of our
borings except for EB-5 and EB-6. Ground water was also not encountered in the borings
completed in November of 2000_ Ground water at this site would be classified as "perched"
ground water. Perched ground water occurs when rain or surface water infiltrates through
upper, looser, and more -permeable soils, such as the fills on the site, and is trapped on top of
or in the upper portions of the less -permeable soils, such as the underlying lodgment till. It
should be noted that fluctuations in the level of the ground water may occur due to the time of
the year, on- and off -site land use, and variations in the amount of rainfall.
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II. DESIGN RECOMMENDATIONS
5.0 INTRODUCTION
It is our opinion that, from a geotechnical standpoint, the proposed track and field
improvements and new light pole installation are suitable for the proposed areas provided that
the recommendations contained herein are properly followed. The existing fill and lodgment
till are expected to have low permeability, and therefore an underdrain system for both new
athletic fields is warranted. If winter construction is expected, the existing soils will be
difficult to manage due to perched ground water.
Up to 10 feet of existing fill was encountered in each exploration boring. Light pole
foundations should be designed with lateral and vertical capacities that are applicable to the
material in which they are embedded; the subsurface conditions observed at the light pole
locations vary from 3.5 feet of existing fill at the location of EB-1 to 10 feet of existing fill at
EB-2.
6.0 EROSION HAZARDS AND MITIGATION
As of October 1, 2008, the Washington State Department of Ecology (Ecology) Construction
Storm Water General Permit (also known as the National Pollutant Discharge Elimination
System [NPDES] permit) requires weekly Temporary Erosion and Sedimentation Control
(TESC) inspections for all sites I or more acres in size that discharge storm water to surface
waters of the state. The TESC inspections must be completed by a Certified Erosion and
Sediment Control Lead (CESCL) for the duration of the construction. TESC reports do not
need to be sent to Ecology, but should be logged into the project Storm Water Pollution
Prevention Plan (SWPPP). If the project does not require a SWPPP, the TESC reports should
be kept in a file on -site, or by the permit holder if there is no facility on -site. Ecology also
requires weekly turbidity monitoring by a CESCL of storm water leaving a site for all sites
5 acres or greater. Ecology requires a monthly summary report of the turbidity monitoring
results (if performed) signed by the NPDES permit holder. If the monitored turbidity equals
or exceeds 25 nephelometric turbidity units (NTU) (Ecology benchmark standard), the project
best management practices (BMPs) should be modified to decrease the turbidity of storm water
leaving the site. Changes and upgrades to the BMPs should be continued until the weekly
turbidity reading is 25 NTU or lower. If the monitored turbidity exceeds 250 NTU, the results
must be reported to Ecology within 24 hours and corrective action taken. Daily turbidity
monitoring is continued until the corrective action lowers the turbidity to below 25 NTU.
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In order to meet the current Ecology requirements, a property developed, constructed, and
maintained erosion control plan consistent with City of Renton standards and best management
erosion control practices will be required for this project. Associated Earth Sciences, Inc.
(AESI) is available to assist the project civil engineer in developing site -specific erosion control
plans. Based on past experience, it will be necessary to make adjustments and provide
additional measures to the TESC plan in order to optimize its effectiveness. Ultimately, the
success of the TESC plan depends on a proactive approach to project planning and contractor
implementation and maintenance.
The erosion hazard of the site soils is high. The most effective erosion control measure is the
maintenance of adequate ground cover. Maintaining cover measures atop disturbed ground
provides the greatest reduction to the potential generation of turbid runoff and sediment
transport. During the local wet season (October 151 through March 31'), exposed soil should
not remain uncovered for more than 2 days unless it is actively being worked. Ground -cover
measures can include erosion control matting, plastic sheeting, straw mulch, crushed rock or
recycled concrete, or mature hydroseed.
Flow -control measures are also essential for collecting and controlling the site runoff. Flow
paths across slopes should be kept to less than 50 feet in order to reduce the erosion and
sediment transport potential of concentrated flow. Ditch/swale spacing will need to be
shortened with increasing slope gradient. Ditches and swales that exceed a gradient of about
7 to 10 percent, depending on their flow length, should have properly constructed check dams
installed to reduce the flow velocity of the runoff and reduce the erosion potential within the
ditch. Flow paths that are required to be constructed on gradients between 10 to 15 percent
should be placed in a riprap-lined swale with the riprap properly sized for the flow conditions.
Flow paths constructed on slope gradients steeper than 15 percent should be placed in a pipe
slope drain. AESI is available to assist the project civil engineer in developing a suitable
erosion control plan with proper flow control.
Some fine-grained surface soils are the result of natural weathering processes that have broken
down parent materials into their mineral components. These mineral components can have an
inherent electrical charge. Electrically charged mineral fines will attract oppositely charged
particles and can combine (flocculate) to form larger particles that will settle out of suspension.
The sediments produced during the recent glaciation of Puget Sound are, however, most
commonly the suspended soils that are carried by site storm water. The fine-grained fraction
of the glacially derived soil is referred to as "rock flour," which is primarily a silt -sized
particle with no electrical charge. These particles, once suspended in water, may have settling
times in periods of months, not hours.
Therefore, the flow length within a temporary sediment control trap or pond has virtually no
effect on the water quality of the discharge since it is not going to settle out of suspension in
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the time it takes to flow from one end of the pond to the other. Reduction of turbidity from a
construction site is almost entirely a function of cover measures and flow control. Temporary
sediment traps and ponds are necessary to control the release rate of the runoff and to provide
a catchment for sand -sized and larger soil particles, but are very ineffective at reducing the
turbidity of the runoff.
Silt fencing should be utilized as buffer protection and not as a flow -control measure. Silt
fencing is meant to be placed parallel with topographic contours to prevent sediment -laden
runoff from leaving a work area or entering a sensitive area. Silt fences should not be placed
to cross contour lines without having separate flow control in front of the silt fence. A
swalelberm combination should be constructed to provide flow control rather than let the
runoff build up behind the silt fence and utilize the silt fence as the flow -control measure.
Runoff flowing in front of a silt fence will cause additional erosion, and usually will cause a
failure of the silt fence. Improperly installed silt fencing has the potential to cause a much
larger erosion hazard than if the silt fence was not installed at all. The use of silt fencing
should be limited to protect sensitive areas, and swales should be used to provide flow control.
6.1 Erosion Hazard Miti ation
To mitigate the erosion hazards and potential for off -site sediment transport, we would
recommend the following:
1. The winter performance of a site is dependent on a well -conceived plan for control of
site erosion and storm water runoff. It is easier to keep the soil on the ground than to
remove it from storm water. The owner and the design team should include adequate
ground -cover measures, access roads, and staging areas in the project bid to give the
selected contractor a workable site. The selected contractor needs to be prepared to
implement and maintain the required measures to reduce the amount of exposed
ground. A site maintenance plan should be in place in the event storm water turbidity
measurements are greater than the Ecology standards.
2. All TESL measures for a given area to be graded or otherwise worked should be
installed prior to any activity within an area other than installing the TESC features.
3. During the wetter months of the year, or when large storm events are predicted during
the summer months, each work area should be stabilized so that if showers occur, the
work area can receive the rainfall without excessive erosion or sediment transport. The
required measures for an area to be "buttoned -up" will depend on the time of year and
the duration the area will be left un-worked. During the winter months, areas that are
to be left un-worked for more than 2 days should be mulched or covered with plastic.
During the summer months, stabilization will usually consist of seal -rolling the
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subgrade. Such measures will aid in the contractor's ability to get back into a work
area after a storm event. The stabilization process also includes establishing temporary
storm water conveyance channels through work areas to route runoff to the approved
treatment facilities.
4. All disturbed areas should be revegetated as soon as possible. If it is outside of the
growing season, the disturbed areas should be covered with mulch, as recommended in
the erosion control plan. Straw mulch provides the most cost-effective cover measure
and can be made wind -resistant with the application of a tackifier after it is placed.
5. Surface runoff and discharge should be controlled during and following development.
Uncontrolled discharge may promote erosion and sediment transport. Under no
circumstances should concentrated discharges be allowed to flow over the top of steep
slopes.
6. Soils that are to be reused around the site should be stored in such a manner as to
reduce erosion from the stockpile. Protective measures may include, but are not
limited to, covering with plastic sheeting, the use of low stockpiles in flat areas, or the
use of straw bales/silt fences around pile perimeters. During the period between
October 151 and March 3 V, these measures are required.
7. On -site erosion control inspections and turbidity monitoring (if required) should be
performed in accordance with Ecology requirements. Weekly and monthly reporting to
Ecology should be performed on a regularly scheduled basis. TESC monitoring should
be part of the weekly construction team meetings. Temporary and permanent erosion
control and drainage measures should be adjusted and maintained, as necessary, at the
time of construction.
It is our opinion that with the proper implementation of the TESC plans and by field -adjusting
appropriate mitigation elements (BMPs) during construction, as recommended by the erosion
control inspector, the potential adverse impacts from erosion hazards on the project may be
mitigated.
7.0 SITE PREPARATION
We understand that new site grades will be similar to existing site grades, and approximately
the upper I to 2 feet of existing soil will be removed from the football field prior to
constructing the turf areas and associated subgrade. Site preparation for the renovated track
and field areas should include removal of the existing sod and topsoil, and regrading to
establish design subgrade elevation in preparation for the installation of the new subdrain
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system. Any organic -rich topsoil or organic fill soils exposed during grading should be
overexcavated and replaced with structural fill. We recommend that the surface of the
subgrade soils exposed during grading be compacted with a smooth -drum, vibratory roller to
at least 90 percent of the modified Proctor maximum dry density, as determined by the
ASTM: D 1557 test procedure, or to a firm and unyielding surface.
The athletic field and track subgrades should then be proof -rolled using a loaded dump truck or
other suitable equipment under the observation of the geotechnical engineer or their
representative. If soft or yielding areas are observed during proof -rolling, additional
preparation might be required. Depending upon field conditions at the time of construction,
additional preparation could include overexcavation and replacement of yielding or excessively
organic soils with structural fill, use of a geotextile fabric, soil cement admixture stabilization,
or some combinations of these methods. In those areas where geotextiles are used, the
geotextile should be overlain by at least i foot of structural fill. The amount of overexcavation
will depend on the time of year construction occurs, the amount of precipitation during this
time, and the amount of care the contractor takes in protecting the exposed subgrade.
The on -site soils contain a high percentage of fine-grained material, which makes them
moisture -sensitive and subject to disturbance when wet. The contractor must use care during
site preparation and excavation operations so that the underlying soils are not softened. If
disturbance occurs, the softened soils should be removed and the area brought to grade with
structural fill. It should be noted that the moisture content of much of the on -site soils was
observed to be over the optimum levels for achieving moisture compaction at the time of our
field exploration. Perched ground water was also observed at or near the ground surface in
many of our borings.
If construction will proceed during wet weather, we recommend that placement of crushed
rock fill be considered in construction staging areas to form a working surface. The crushed
rock used in these areas should be placed in a layer at least 10 inches thick. The rock may
need to be underlain by a geotextile fabric, such as Mirafi 50OX, or equivalent.
7.1 Permanent Cut and Fill Slopes
We do not anticipate that significant new permanent cut and fill slopes will be necessary for
this project. However, the following recommendations may be applied to slopes shorter than
8 feet in height.
Permanent cut and structural fill slopes should be graded no steeper than 2H:1V
(Horizontal: Vertical). Slopes should be hydroseeded as soon as possible after grading. Cut
slopes in natural soils that are steeper than 2H:1V may be protected by a rockery or an
engineered retaining wall. Rockeries should not be used to face fills unless the fills are
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reinforced. Temporary cut slopes into unsaturated till should be made no steeper than 1H:1V.
Temporary cut slopes into the existing fill should be made no steeper than 1.514:1V. Actual
cut slope angles may have to be adjusted depending upon actual field conditions at the time of
construction.
8.0 STRUCTURAL FILL
Structural fill will be necessary to establish desired grades for the athletic fields and any new
utility trench backfill. All references to structural fill in this report refer to subgrade
preparation, fill type, placement, and compaction of materials, as discussed in this section.
Our recommendations for the placement of structural fill are presented in the following
sections.
8.1 Fill Placement
After stripping, excavation, and any required overexcavation have been performed to the
satisfaction of the geotechnical engineer/engineering geologist, the upper 12 inches of exposed
ground should be recompacted to 90 percent of the modified Proctor maximum density using
ASTM:D 1557 as the standard. If the subgrade contains too much moisture, adequate
recompaction may be difficult or impossible to obtain and should probably not be attempted.
In lieu of recompaction, the area to receive fill should be blanketed with washed rock or quarry
spalls to act as a capillary break between the new fill and the wet subgrade. Where the
exposed ground remains soft and further overexcavation is impractical, placement of an
engineering stabilization fabric may be necessary to prevent contamination of the free -draining
layer by silt migration from below.
After recompaction of the exposed ground is tested and approved, or a free -draining rock
course is laid, structural fill may be placed to attain desired grades. Structural fill is defined as
non -organic soil, acceptable to the geotechnical engineer, placed in maximum 8-inch loose
lifts, with each lift being compacted to 90 percent of the modified Proctor maximum density
using ASTM:D 1557 as the standard. In the case of utility trench filling, the backfill may also
need to be placed and compacted in accordance with current local codes and standards. The
top of the compacted fill should extend horizontally outward a minimum distance of 3 feet
beyond the locations of pavement edges or other structures before sloping down at a maximum
angle of 2H:1V.
The contractor should note that any proposed fill soils must be evaluated by AESI prior to their
use in fills. This would require that we have a sample of the material 72 hours in advance of
filling activities to perform a Proctor test and determine its field compaction standard. Soils in
which the amount of fine-grained material (smaller than the No. 200 sieve) is greater than
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approximately 5 percent (measured on the minus No. 4 sieve size) should be considered
moisture -sensitive. Use of moisture -sensitive soil in structural fills should be limited to
favorable dry weather conditions. The on -site existing fill and glacial sediments contain
substantial amounts of silt and are considered highly moisture -sensitive. With the exception of
those portions of the existing fill soils containing substantial quantities of topsoil and other
organic debris, these materials are acceptable for use as structural fill beneath the drainage fill
provided they are placed and compacted at a moisture content that allows for the minimum
specified compaction presented in this report.
Reuse of on -site soils during wet ,site or weather conditions is expected to be difficult or
impossible due to the moisture sensitivity of site soils and presence of shallow ground water.
Construction equipment traversing the site when the soils are wet can cause considerable
disturbance. If fill is placed during wet weather or if proper compaction cannot be obtained, a
select import material consisting of a clean, free -draining gravel and/or sand should be used.
Free -draining fill consists of non -organic soil with the amount of fine-grained material limited
to 5 percent by weight when measured on the minus No. 4 sieve fraction with at least 25
percent retained on the No. 4 sieve.
8.2 Subsurface Drains (Underdrains
We recommend that a subsurface drainage system be provided below the new field due to the
low permeability of the underlying existing fill and till soils. The new underdrain system
should consist of perforated, polyvinyl chloride (PVC) pipes, a minimum of 4 inches in
diameter, placed approximately 15 to 20 feet apart. The pipes should have an invert of at least
12 inches below final grade and be fully enveloped in at least 6 inches of free -draining
material, containing less than 3 percent fines. The diameter of the drainage material should be
larger than the size of the perforations in the drainpipe. The remainder of the drainage trench
backfill should consist of free -draining material, conforming to the 2008 Washington State
Department of Transportation (WSDQT) Standard Specifications for Road, Bridge and
Municipal Construction, Section 9-03.12(4), "Gravel Backfill for Drains," which freely
communicates with the field surfacing. We defer to D.A. Hogan for design of the new field's
surfacing material.
8.3 Subsurface Drain Trenching
Construction of the subsurface drains will require trenching into the underlying sediments and
existing fill. As part of this study, borings were advanced to provide preliminary information
on sediment density and ease of trenching. The fill soils within the proposed development area
are in a loose to medium dense condition and should therefore be backhoe-excavated with
limited difficulty. The underlying natural sediments consist of till, which is in a dense to very
dense condition. The till will be more difficult to excavate than the overlying fill soils,
January 28, 2009 ASSOCIATED EARTH SCIENCES, INC.
SGBIld - KE000669B2 - Projeas1200006 HEMP Page 11
Subsurface Exploration and
Lindbergh High School Athletic Field Improvements Geotechnical Engineering Report
Renton, Washington Design Recommendations
particularly where gravel and cobbles are present. Therefore, the contractor should be
prepared to encounter dense to very dense sediments during the construction of the subsurface
drains, and suitable excavation equipment should be utilized to expedite construction.
8.4 Subfield Drainage Aggregate
We anticipate that one or two layers of drainage aggregate will be placed and compacted over
the prepared field subgrade and below the synthetic surfacing on the football field and below
the natural turf on the eastern field. The drainage aggregate is a very specialized manufactured
crushed product that provides a compactable, stable working surface while maintaining a
minimum infiltration rate. The drainage aggregate should be tested for gradation and approved
by D.A. Hogan prior to delivery on -site. Daily sampling and testing during placement is
recommended. The material should be kept moist during transport, placement, and
compaction to reduce the potential for fines segregation. Once placed and compacted, the
material should be field-tested for density and permeability. If field permeability test results
are below the minimum project requirements, the material may need to be loosened and
recompacted or removed and replaced with materials that meet the minimum permeability
requirements. Haul roads should be configured as to not over -compact the drainage aggregate.
9.0 GROUND MOTION
Based on the site stratigraphy and visual reconnaissance of the site, it is our opinion that any
earthquake damage to the proposed light pole structures, when founded on suitable bearing
strata, would be caused by the. intensity and acceleration associated with the event and not any
of the above -discussed impacts. Structural design of the light pole foundations should follow
2006 International Building Code (IBC) standards using Site Class "C", as defined in Table
1615.1.1. The 2006 IBC seismic design parameters for short period (Ss) and 1-second period
(Si) spectral acceleration values were determined by the latitude and longitude of the project
site using the United States Geological Survey (USGS) National Seismic Hazard Mapping
Project website (http://egdesign.er.usgs.gov). Based on the current 2002 data, the USGS
website interpolated ground motions at the project site to be 1.46g and 0.50g for building
periods of 0.2 and 1.0 seconds, respectively, with a 2 percent chance of exceedence in
50 years.
January 28, 2009 ASSOCIATED EARTH SCIENCES, INC.
SGB/ld - KE000669B2 - Projects1200"69YKE1WP Rage 12
Subsurface Exploration and
Lindbergh High School Athletic Field Improvements Geotechnical Engineering Report
Renton, Washington Design Recommendations
10.0 LIGHT POLE FOUNDATIONS
10.1 Compressive Capacities
We anticipate that the depth of existing fill will vary somewhat at different proposed light pole
locations. For this project, we anticipate that lateral capacities will be the most critical design
factor for the light pole foundations, and will likely exert the most control over drilled pier
length. It would be feasible to install light pole foundations that terminate within the existing
fill, however if this is done, the end -bearing portion of the axial compressive capacity should
be neglected in the design. Vertical capacity can be achieved through friction along the pier
shafts, as described below. For those piers that extend at least 3 feet into undisturbed till, an
allowable end -bearing capacity of 5 tons per square foot (tsf) may be assumed for design.
10.2 Frictional Resistance
For frictional resistance along the shaft of the drilled pier, acting both in compression and in
uplift, an allowable skin friction value of 200 pounds per square foot (psf) for the existing fill
and 500 psf for the underlying native till is recommended. It is also recommended that
frictional resistance be neglected in the uppermost 2 feet below the ground surface. The
allowable skin friction value includes a safety factor of at least 2.0.
10.3 Lateral Capacities
For design against lateral forces on the drilled pier, two methods are typically used. The
parameter used to select the most appropriate design method is the length to pier stiffness
factor ratio LIT, where "L" is the pier length in inches and "T" is the relative stiffness factor.
The relative stiffness factor for the pier (T) should be computed by:
T = s EI
nh
where: E = modulus of elasticity (pounds per square inch [psi])
I = moment of inertia (in)
nn = constant of horizontal subgrade reaction (pounds per cubic inch [pci])
The factors "E" and "I" are governed by the internal material strength characteristics of the
pier. Representative values of "m" for the soil observed on this site are presented
subsequently. Piers with an LIT ratio of less than 3 may be assumed to be relatively rigid and
act as a pole. The passive pressure approach may be used for this condition. For piers with
January 28, 2009 ASSOCIATED EARTH SCIENCES, INC.
SGBRd - KEQ90669B2 - Projem1200006691KEMP Page 13
Subsurface Exploration and
Lindbergh High School Athletic Field Improvements Geotechnical Engineering Report
Renton, Washington Design Recommendations
an LIT ratio greater than 3, the modulus of subgrade reaction method is typically used. Both
of these methods are discussed below.
Modulus of Suhgrade Reaction Method
Using this method, the pier is designed to resist lateral loads based on acceptable lateral
deflection limits. For granular soils, the coefficient of horizontal subgrade reaction is
considered to increase linearly with depth along the pier. The expression for the soil modulus
is Kn = (nt,)(X/B), where "nh" is the coefficient of modulus variation, "X" is the depth below
the ground surface, and "B" is the pier diameter. We recommend using the value for the
coefficient of modulus variation (nn) of 150 pci for very dense glacial soils and 30 pci for
existing fill soils.
Passive Pressure Method
Lateral loads on the shallow foundation caused by seismic or transient loading conditions may
be resisted by passive soil pressure against the side of the foundation. An allowable passive
earth pressure of 350 pounds per cubic foot (pcf), expressed as an equivalent fluid unit weight,
may be used for that portion of the foundation embedded within dense to very dense native till.
Below a depth of 2 feet in existing loose to medium dense fill soils, an allowable passive earth
pressure of 150 pcf should be used. The above value only applies to foundation elements cast
"neat" against undisturbed soil. For new structural fill placed around the pier shaft, a passive
earth pressure value of 250 pcf is recommended. All fill must be placed as structural fill and
compacted to at least 95 percent of ASTM:D 1557. Passive resistance within the upper 2 feet
should be ignored. However, passive values presented are used assuming an equivalent
triangular fluid pressure distribution over 2 pier diameters beginning at the surface and held at
a constant depth greater than 8 feet. The triangular pressure distribution is truncated above
2 feet.
The presence of large -diameter boulders below the proposed light pole locations is possible.
The owner should be prepared to move the light pole locations if boulders are encountered.
Some drilling contractors can employ specialized drilling equipment to drill through large
boulders, but these methods are often very time-consuming and/or expensive.
11.0 PROJECT DESIGN AND CONSTRUCTION MONITORING
We are available to provide additional geotechnical consultation as the project design develops
and possibly changes from that upon which this report is based. We recommend that AESI
perform a geotechnical review of the plans prior to final design completion. In this way, our
January 28, 2009 ASSOCIATED EARTH SCIENCES, INC.
SGs11d - KE000M982 - Projew 120"669wv WP Page 14
Subsurface Exploration and
Lindbergh High School Athletic Field Improvements Geotechnical Engineering Report
Renton, Washington Design Recommendations
earthwork and foundation recommendations may be properly interpreted and implemented in
the design.
We are also available to provide geotechnical engineering and monitoring services during
construction. The integrity of the athletic fields surfacing and light poles depends on proper
site preparation and construction procedures. In addition, engineering decisions may have to
be made in the field in the event that variations in subsurface conditions become apparent.
Construction monitoring services are not part of this current scope of work. If these services
are desired, please let us know, and we will prepare a cost proposal.
We have enjoyed working with you on this study and are confident that these recommendations
will aid in the successful completion of your project. If you should have any questions or
require further assistance, please do not hesitate to call.
Sincerely,
ASSOCIATED EARTH SCIENCES, INC.
Kirkland, Washington
i 1
Susan G. Beckham, P.E.
Senior Project Engineer
Attachments: Figure l: Vicinity Map
Figure 2: Site and Exploration Plan
Appendix: Exploration Logs
Laboratory Results
. "p. M6q I
23580
�"' l-G � V& C?
► N)NAL
Kurt D. Merriman, P.E.
Principal Engineer
January 28, 2009 ASSOCIATED EARTH SCIENCES, INC.
SGR/!d - KE0%69R2 - Projects Q000066917VWP Page 15
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APPROXIMATE LOCATION OF
EXPLORATION BORING WITH
DEPTH TO BEARING SOILS
TYP - AESI 2000
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APPROXIMATE LOCATION OF
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., DEPTH TO BEARING SOILS
TYP -AESI 2009
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Associated Earth Sciences, Inc. SITE AND EXPLORATION PLAN FIGURE 2
iil®
''IN LINDBERGH HIGH SCHOOL RATEn1/09
EF1 RENT -ON, WASHINGTON
fff]/i Airti ii["
APPENDIX
•
Wel-graded gravel and
Terms Describing Relative Density and Consistency
m
°OQ6
GW
gravel with sand, little to
Densily SPTbfowslfoot
c
LL
no fines
Very Loose 0104
Coarse-
°° °p o a
° ° ° ° o
GP
Poorly -graded gravel
>
m
o 1
U
,
Vrl
Grained Sons G�Aedium Dense 1 p to 30 Test Symbols
rq
G ° ° ° °
and gravel with sand,
Dense 30 to 54
c
P.
o ° c ° °
little to no fines
Very Dense >50 G s Grain Size
N
0
-A Z
0 c
° o° o°
M F Moisture Conlerit
Consistency SPT%lowslioot A s Atterberg Lirnits
C b
Silty gravel and silly
Very Soft 0 to 2 C- Chernical
o
Y
GM
gravel with sand
er Soft 2 to 4 DO R Dry Density
o m
Grained Solis Medium Stiff 4 to 8 K w Permeability
2 x
Stiff 8 to 15
Clayey gravel and
very Stiff 15 to 30
m
GC
clayey gravel with sand
Hard >30
o
Component Definitions
e
Weft -graded sand and
Descriptive Term Size Range and Sieve Number
SW
sand with gravel, file
Boulders Larger than 12'
.
to no fines
Cobbles 3' l012'
c
Gravel T to No. 4 (4.75 mm)
;.'{ "
Poorly -graded sand
u
v,
s
m
5P
and sand with gravel,
Coarse Gravel 3' to 3/4•
Fine Gravel 314'tD No. d (4,75rnm)
m
c
o
d
Ifttfe to no fines
Sand No. 4 (4.75 mm) to No. 2DD (0_075 mm)
rT
Coarse Sand No. 4 (4.75 mm) to No. 10 (2.DD mm)
N
° m
Silty sand and
Medium Sarrd No. 10 (2.Do mm) to No. 40 (0.425 mm)
5M
Bitty sand with
Fine Sand No. 40 (0.425 mrn) to No. 200 (CO75 mm)
m
m
c EL
�t
gravel
Silt and Clay Smaller than No. 200 (0.075 mm)
0
m
=
St:
d Clayey sand an
(3) Estimated Percentage Moisture Content
clayey sand with gravel
e by D Absence of moisture,
toPercents
tN/_ edusty, dry to the touch
Trace <5 Slightly Moist - Perceptible
sandy sift, gravelly slit,
m
m
o
111111MLISIlt'
sift with sand or ravel
g
Few 5 to 10 moisttae
We 151025 Moist -Damp tart no visible
co
w m
With - Non -primary coarse water
Clay of low to medium
c
0
constituents: > 15% Very Moist- Water visible but
N
6 m
CL596
plasticity; si sandy, or
Fines content between not free draining
z
gravelly clay, lean clay
and 15% Wei -Visible free water. us !r
from below water table
a
CO
_—_
Organic clay or sift of low
Symbols
m
Cr
:3
f71-
plasticity
61owsV or
g
_
Sampler portion of S' Cement grout
Type surface seat
� Simper Type
Elastic sift, cla a sift, silt
Y Y
;e
MH
with micaceous or
2.;-Cr � Benicrrte
plit-Spoon Description {e} seat
o
dialomaceous fine sand or
Sampler 3.0" OD Split -Spoon Sampler _ der pack with
mi
silt
{SPT) 3.25' OD Split -Spoon Fling Sampler t.l blade casing
5epr,
Clay of high plasticity,
m
GH
sandy or gravelly clay, fat
Bulk sample 3.0' OD -thin Waal Tube Sampler - Screened casing
W
10E
clay with sand or gravel
(including Shelby tube) or
''
Grab Sample' er pack
m
c
7
rs
End tap
er
o Portion not recoved
/ //�
/f
i
Organic clay or silt of
'-
J
�`%,
off
medium to high
n
t i Percentage by dry weight {41 Depth of ground wafer
plasticity
pi sticity
Mi (SPT) Standard Penetration Test A fp At time of drilling
Static water level (dale)
Accordance
In General Accordance with
In General
a
,n
Beat, muck and other
E?
P7
highly organic soils
standard Practice for Description Combined USCS symbols used for
=
a (00
and identification of Solls VSTM D-2488) fines between 5% and 15%
Cfassirrtations of sDU In this report are based on visual field and/or laboratory observattans, which include demny7wnslstency, moisture condition, grain stze, and
plastichy estimates and should not be construed to imply field or laboratory testing unless presented herein. Visual -manual and/or laboratory dassificafion
methods of ASTI A D-2487 and D-24aa were used as an identification guide for the Unified Sol Ciassification System.
Associated Earth Sciences, Inc.
ra M IN .:. EXPLORATION LOG KEY FIGURE Al
Associated Earth Sciences, Inc.
Exploration Log
,(
'"'w9
Project Number
Exploration Number
Sheet
KE000669B
EB-1
1 of 1
Project Name Lindber h Hi h School Ground Surface Elevation (ft)
Location Renton WA Datum NIA
Driller/Equipment Boretec Track Drill Date Start/Finish
Hammer Weight/Drop 140# i 30#1 Hole Diameter (in) 7"
a
u
Q E
O
°Y
5
Blows/Foot
rn
n
S E
{6>,
� C
T
(�
DESCRIPTION
p
LE
3:
m
10 20 30 40
L_
D
Fill
T
Snow over sod.
Loose, wet, brown, silty fine SAND, few gravel.
S-1
4
3
A6
3
5
5_2
T
10
4
3
--------- ------------------
Lodgement Till
Very dense, wet, gray -brown, silty fine to medium SAND, few gravel,
29
5-3
43
82
39
10
S-4
Becomes moist, trace gravel, with 2" fine to coarse sand layer_
Z�5
Bottom of exploration boring at 11 feet
Saturated ground conditions at time of drilling (rain on snow). Perched ground water
from 0 to B' at time of drilling.
15
20
25
30
35
Sampler Type (ST):
m 2" OD Split Spoon Sampler (SPT) ❑ No Recovery M - Moisture Logged by: EJL
m 3" OD Split Spoon Sampler (D & M) [] Ring Sample -V Water Level (} Approved by:
® Grab Sample Q Shelby Tube Sample t Water Level at time of drilling (ATD)
Associated Earth Sciences, Inc.
Exploration Log
S
Project Number
Exploration Number Sheet
KE000669B
EB-2 1 of 1
Project Name Lindbergh High School Ground Surface Elevation (ft)
Location Renton, WA Datum NLA
Driller/Equipment Boretec Track Drill Date StarUFinish 1712AIflR1171�glfl$_
Hammer Weight/Drop 140# 1 30" Hole Diameter (in) T
°
'
L Z
>
BiowslFoot
N
a
S E
°
T
DESCRIPTION
to
o,
o
10 20 30 40
Fill
Snow over sad over very dense, wet, dark brown, silty SAND, with
scattered organics.
S-1
22
36
60
Lodgement Till
Very dense, moist to wet, gray -brown, silty SAND, becomes moist, gray,
5T
S-2
few gravel.
0111
S-3
0!
501
"
Bottom of exploration boring at 8 feet
10
Perched ground water from 0 to 5' at time of drilling.
15
20
25
30
35
Sampler Type (ST):
m 2" OD Split Spoon Sampler (SPT) F1 No Recovery M - Moisture Logged by: EJL
3" OD Split Spoon Sampler (D & M) 1] Ring Sample Q Water Level() Approved by:
® Grab Sample Z Shelby Tube Sample t Water Level at time of drilling (ATD)
Associated Earth Sciences, Inc.
Exploration Log
1,
0
Project Number
Exploration Number
Sheet
KE000669B
EB-3
1 of 1
Project Name Lindbergh High School Ground Surface Elevation (ft)
Location Renton WA Datum N/A
Driller/Equipment Boretec Track Drill Date StarUFinish 12/291llfi.12/29102
Hammer Weight/Drop 140# 1 30" Hole Diameter (in) j"
u
N
U
aR
C
O
�,
�
7
°+
z
y
Blows/Foot
N
N
CL
T c
v)
DESCRIPTION
o
W.
m
10 20 30 40
t
Q
Fill
Snow over sod over loose to medium dense, wet, brown, silty SAND, few
gravel.
S-1
5
7
Al
s
5
Becomes gray -brown, silty fine SAND, scattered organics.
5
S-2
4
9
5
37
Lodgement Till
S-3
Very dense, moist, gray, silty SAND, with gravel.
A
L501-
10
S 4
22
!
501
Bottom of exploration boring at 1&75 feet
Perched ground water 0 to 6 112' at time of drilling.
15
20
25
30
35
Sampler Type (ST):
M 2" OD Split Spoon Sampler (SPT) No Recovery M - Moisture Logged by; EJL
3" OD Split Spoon Sampler (D & M) Ring Sample V Water Level() Approved by:
® Grab Sample Z Shelby Tube Sample 1 Water Level at time of drilling (ATD)
Associated Earth Sciences, Inc.
Exploration Log
Project Number Exploration Number
Sheet
KE000669B EB-4
1 of 1
Project Name Lindbergh High SchQQI Ground Surface Elevation (ft)
Location Renton WA Datum N/A
Driller/Equipment Boretec Track Drill Date Start/Finish
Hammer Weight/Drop . 140# 130P1 Hole Diameter (in) 71,
L�
o
6
>
Blows/Foot
2
n
❑
5 E
T W
E 7
U' rn
0
m
O
DESCRIPTION
10 20 30 40
S 1
Fill
Snow over sod over 8" sandy topsoil over loose, moist, tan, fine to coarse
2
4
9
SAND, trace silt,
5
5 2
Medium dense, moist to wet, brown, silty SAND, scattered organics.
12
AL
7
10
--- --
Medium dense, moist to wet, gray, silty fine SAND, trace gravel.
7
5
�
S-3
z
A,
Becomes loose, saturated.
g
5-4
Scattered organics observed.
3
2
+ 4
2
10
J _ _ W _ — — Lodgement Till
T5 5
Very dense, moist, gray -brown, silty SAND, few gravel.
11
1
a
Bottom of exploration boring at 13 feet
15
Perched groundwater at Fat time of drilling.
20
25
30
35
Sampler Type (ST):
m 2" OD Split Spoon Sampler (SPT) a No Recovery M - Moisture Logged by: EJL
3" OD Split Spoon Sampler (D & M) 1] Ring Sample Q Water Level () Approved by:
® Grab Sample Z Shelby Tube Sample T Water Level at time of drilling (ATD)
Associated Earth Sciences, Inc.
Exploration Log
'
Project Number Exploration Number
Sheet
KE000669B EB-5
1 of 1
Project Name Undber h High School Ground Surface Elevation (ft)
Location Renton WA Datum N/A
DrillerlEquipment Boretec Track Drill Date Start/Finish 1217910R 19129109
Hammer WeighUDrop 140# 130" Hole Diameter (in) 7"
CL
F
- N
N
J
N
Blows/Foot
2
n
S E
2}
E
o
8
T
C7 cn
DESCRIPTION
o
m
10 20 30 40
r
S 1
Fill
Sod over 8" sandy topsoil over loose, moist, brown, fine to coarse SAND,
3
4
9
trace silt.
5
S-2
Dense, wet, dark brown, silty SAND.
16
A
7
19
Dense, moist, gray, silty SAND, with gravel.
18
5
S 3
11
15
A32
17
Loose, wet, dark brown, silty SAND, abundant organics.
3
S-4
3
9
10
-------------------__-- —-----
(/r? d , Cjf1 -u'� T (11
6
S 5
Dense, moist, gray, silty SAND, fee�l'J gravel.
8
•
7
12
25
Bottom of exploration boring at 11.5 feet
No ground water at time of drilling.
15
20
25
30
35
Sampler Type (ST):
2" OD Split Spoon Sampler (SPT) No Recovery M - Moisture Logged by: EJL
3" OD Split Spoon Sampler (D & M) Ring Sample V Water Level() Approved by --
Grab Sample 0 Shelby Tube Sample Z Water Level at time of drilling (ATD)
Associated Earth Sciences, Inc.
Exploration Log
N ^ ;
Project Number
Explorafion Number
Sheet
KE000669B
EB-6
1 of 1
Project Name Lindbergh High School Ground Surface Elevation (ft)
Location Renton. WA Datum NIA
Driller/Equipment Borete Track Drill Date Start/Finish 121291C1F3.1212910a __
Hammer Weight/Drop 140# 1 30" Hole Diameter (in) 7"
s
in
4-
n E
C
4
�, n
N
J
3
Blows/Foot
N
Q
S E
`°
E
o
d
T to
00
DESCRIPTION
0
r,
3:
m
10 20 30 40
t
Fill
Sod over loose, wet, brown, silty SAND, few gravel_
S-1
4
•
4
5
S-2
Becomes medium dense, brownlorange.
g
Al2
7
5
S-3
24
AL71
Lodgement Tilt
Very dense, moist, green -gray, silty SAND, with gravel.
47
1031
S-4
Becomes gray, gravelly.
Bottom of exploration boring at 10.5 feet
No ground water at time of drilling.
15
20
25
30
35
I
S
Sampler Type (ST):
' m 2" OD Split Spoon Sampler (SPT) ❑ No Recovery M - Moisture Logged by: EJL
T 3" OD Split Spoon Sampler (D & M) 1] Ring Sample Q Water Level 1) Approved by:
® Grab Sample Q Shelby Tube Sample Water Level at time of drilling (ATD)
Associated Earth Sciences, Inc.
Exploration Log
Project Number
Exploration Number
Sheet
KE000669B
EB-7
1 of 1
Project Name Lindbergh High School Ground Surface Elevation (€t)
Location Renton, WA Datum N/A
Driller/Equipment Boretec Track Drill Date Start/Finish 12/29108 12 9/OR
Hammer Weight/Drop 140# / 30" Hole Diameter (in) 71,
a
m
U o
�E
O
N
Blows/Foot
rl
p
s E
T
CD CO
o
io
m
t
DESCRIPTION
"
10 20 30 40
°
Fill
Sod over medium dense, moist to wet, brown/gray, silty SAND, few gravel.
S-1
11
11
A22
11
5
Becomes loose, saturated, brown, scattered organics.
4
S 2
3
•
5
S-3
19
41
Lodgement Till _
22
10
S 4
Dense to very dense, moist to wet, gray, silty SAND, trace gravel.
at "
sal
Bottom of exploration boring at 10.5 feet
Perched ground water 2 112' to 7 1 /2' at time of drilling.
15
20
25
30
35
Sampler Type (ST):
[fl 2" OD Split Spoon Sampler (SPT) F] No Recovery M - Moisture Logged by. EJL
3" OD Split Spoon Sampler (D & M) U Ring Sample Q Water Level (} Approved by:
® Grab Sample Z Shelby Tube Sample t Water Level at time of drilling (ATD)
Associated Earth Sciences, Inc.
Exploration Log
- 7
0LIJ M
Project Number
Exploration Number
Sheet
KE000669B
EB-S
1 of 1
Project Name Lindbergh High School — Ground Surface Elevation (ft)
Location Renton, WA Datum NIA _
DriileNEquipment Boretec Track Drill Date Start/Finish 12129108 12179/019
Hammer Weight/Drop 140# 130" Hole Diameter (in) 71,
.2
—
N
Blows/Foot
N
S
2
CL
s=
b
coE
T U)
0 cn
DESCRIPTION
"
3�
°
10 20 30 40
Fill
Sod over medium dense, saturated, brown, silty SAND, with gravel.
>G
5-1
14
A26
14
5
Becomes loose, moist to wet, scatttered organics_
8
TS-2
4
Aq
4
Lodgement Till
S-3
Dense, Saturated, gray -brown, fine to medium SAND, trace to few silt.
22
A43
20
23
10
S 4
Very dense, red -brown, fine to medium SAND, trace silt, over gravelly silty
15
0!
SAND_
Bottom of exploration boring at 11 feet
Perched ground water 2 112' and 7 1J2'.
15
20
25
30
35
Sampler Type (ST):
m 2" OD Split Spoon Sampler (SPT) No Recovery M - Moisture Logged by: EJL
3" OD Split Spoon Sampler (D & M) U Ring Sample Q Water Level {) Approved by:
® Grab Sample Z Shelby Tube Sample -T Water Level at time of drilling (ATD)
Exploration Log_
ASSDCIATED
EARTH Project Number Exp{oration Number Sheet
SCIENCES, INC KE00669G B-6 1 of 1
Project Name Lindbergh High School Ground Surface Elevation (ft) 430'
Location Renton WA Datum T{)pn SiiruaV
Driller/Equipment Davies 1 Hollow -Stem Auger Date Starl)Finish .L1j_J0A)D,11110L2nfM
Hammer 1NeightlDrop 1409 330" Hole Diameter (in) fill
�'
n
.� o
n
c
>
w
Blows/Foot
En
f°!
a
5 E
`9
��o
6
T
C7 rn
DESCRIPTION
a
5
a
3:
m
tiO 20 30 40
:F.
°
S-1
-----
2
�$
Till
1
Loose, damp, light brown, fine SAND, with gravel and little silt. (SM)
4
5
Very dense, damp, gray, SILTY fine SAND, little gravel. (SM)
20
S-2
33
71
38
0
Grades with gravel.
16
i
S-3
2s
56
30
- 15
Grades with few to little gravel
32
S 4
A90
as
- 20
As above.
l
35
S-5
45
s5
50
MUM of exploration boring at 21 5 feet
25
- 30
35
s.
3
i
Sampler Type (ST):
m 2" OD Split Spoon Sampler (SPT) No Recovery M - Moisture Logged by, BWG
i 3" OD Split Spoon Sampler (D & M) Ring Sample SZ Water Level () Approved ay:
® Grab Sample [Y]e Shelby Tube Sample 1 Water Level at time of drilling (ATD)
Exploration Lv
A,550CIATEC
EARTH
Project Number
Exploration Number
Sheet
SCIENCES, INC
KE00669G
6-5
1 of 1
Project Name Lindbergh High School _ Ground Surface Elevation (ft) 412'
Location Renton WA Datum Topo Sltrvpy
Driller/Equipment Davies f Holfow-Stem Au er Date StarVFinish
Hammer WeighUDrop 140# 130" Hole Diameter (in) R„
a
a�
�, a
J
Blows/Foot
w
T cv
CD cn
DESCRIPTION
m
10 20 30 40
a
S_1
TQRs rass _
4
i
Fill
Loose, damp, brown, SILTY fine SAND, with gravel. (SM)
a
S-2
3
A5
---
2
Till ---
5 I
S-3
Very dense, damp, gray, SILTY fine SAND, little gravel. (SM)
cl "
501
S-4
12
22
Ak54
32
— 10
Bottom of exploration boring at 9 feet
- 15
i
20
- 25
30
35
a
{
ry Sampler Type (ST):
2" OD Split Spoon Sampler (SPT) No Recovery M - Moisture Logged by: i3WG
C 3" OD Split Spoon Sampler (D & M) Ring Sample Q Water Level () Approved by:
® Grab Sample Shelby Tube Samplet Water Level at time of drilling (ATD)
GRAIN SIZE ANALYSIS - MECHANICAL
Date
Project
Project No.
Soil Description
12/29/2008
Lindbergh High School
KE0000669B
Silty Sand little Gravel
Tested By
Location
EBIEP No
Depth
BG
Football Field
EB-4
12.5'
Wt. of moisture wet sample + Tai
975.65
Total Sample Tare
334.54
Wt. of moisture dry
Sample + Tare
908-98
Total Sample wt + tare
908.98
Wt. of Tare
334.54
Total Sample Wt
57 .
Wt. of moisture Dry
Sample
574.44
Total Sample Dry Wt
Moisture %
12%
5nerifiration RerUlrt-mantS
Sieve No.
Diarn_ mm
Wt. Retained
% Retained
% Passing
Minimum
Maximum
3.5
90
0
100.00
3
76.1
0
100.00
2.5
64
0
100.00
2
50.8
0
-
100.00
1.5
38.1
0
-
100.00
1
25.4
0
-
100.00
3/4
19
0
-
100.00
318
9.51
11.37
2.21
97.79
#4
4.76
30.9
6.00
94.00
#8
2.38
57.44
11-16
88.84
#10
2
65.2
12-67
87.33
#20
0.85
99.47
19.33
80.67
#40
0.42
162.14
31.50
68.50
#60
0.25
247.58 1
48.10
51.90
#100
0.149
317-12
61-61
1 38.39
#200
0.074
368.82
71.66
1 28-34
US STANDARD SIEVE NOS,
3" 314" NO.4 NO.16 NO.40 NO.200
100
-
80
- - ---- - ---
- - r
LL
i
40
T
-
20
0 I _.-.. - 1 1 1
100 10 1 0.1
Grain Size, mm
ASSOCIATED EARTH SCIENCES, INC.
911 51h Ave., Suite 100 Kirkland, WA 98033 425-827-7701 FAX 425-B27.5424
0.01
GRAIN SIZE ANALYSIS - MECHANICAL
Date
12/29/2008
Project
Lindbergh High School
Project No.
KE0000669B
Soil Description
Silty Sand
Tested By
SG
Location
Football Field
EB/EP No
E13-5
Depth
2.5'
Wt. of moisture wet sample + Tai
923.48
Total Sample Tare
297.29
Wt. of moisture dry Sample + Tare
849.43
Total Sample wt + tare
T4977--
Wt, of Tare
297.29
Total Sample Wt
552.
Wt. of moisture Dry Sample
552.14
Total Sample Dry Wt
486.8
Moisture %
13%
5narifiratinn RemirPmPnts
Sieve No.
Diam. mm
Wt. Retained
% Retained
% Passing
Minimum
Maximum
3.5
90
0
-
100.00
3
76.1
0
-
100.00
2.5
64
0
-
100.00
2
50-8
0
-
100.00
1.5
38-1
0
-
100.00
1
25-4
0
-
100.00
314
19
0
-
100.00
318
9.51
32.68
6.71
93.29
#4
4.76
64.85
13.32
86.68
#8
2-38
93.21
19.15
80.85
#10
2
101.93
20.94
79.06
#20
0.85
142.62
29.29
70.71
#40
0.42
207.46
42.61
57.39
#60
0.25
275.25
56.54
43A6
9100
0.149
1 331.36
68.06
1 31.94
9200
0.074
375.08
77.04
22.96
US STANDARD SIEVE NOS.
3" 314" NO.4 NO.16 NO.40 NO.200
100
80
L
60
LL
m 40
IL
20
0 -L--
100 10 1 0.1 0.01
Grain Size, mm
ASSOCIATED EARTH SCIENCES, INC.
911 5th Ave„ Suite 100 Kirkiand, WA 98033 425-827-7701 FAX 425-627-5424
GRAIN SIZE ANALYSIS - MECHANICAL
Date
12129/2008
Project
Lindbergh High School
Tested By
BG
Location
Football Field
Wt. of moisture wet sample + Tai
954.06
Wt. of moisture dry
Sample + Tare
870.23
Wt, of Tare
394.81
Wt, of moisture Dry
Sample
475.42
Moisture %
18%
Project No.
KE0000669B
EB/EP No Depth
EB-7 2.5'
Total Sample Tare
Total Sample wt + tare
Total Sample Wt
Total Sample Dry Wt
Soil Description
Silty Sand with Gravel
394.81
Snarifiratinn RPnuiremants
Sieve No.
Diam. mm
Wt. Retained
% Retained
% Passing
Minimum
Maximum
3.5
90
0
-
100.00
3
76.1
0
-
100.00
2.5
64
0
-
100.00
2
50.8
0
-
100.00
1.5
38.1
0
100.00
i
25.4
0
-
100.00
314
19
8.56
2.12
97.88
3/8
9-51
47.41
11.73
88,27
#4
4.76
73.25
18.12
81.88
#8
2.38
103.86
25.70
74.30
#10
2
110.42
27.32
72.68
#20
0.85
143.02
35.39
64.61
#40
0.42
187.59
46.42
53.58
#60
0.25
244.69
60.54
39-46
#100
1 0.149
1 296.76
73.43
1 26.57
#200
0.074
333-4
82.49
17.51
US STANDARD SIEVE NOS.
3" 314" NO.4 N0,16 NO40 ND,200
100
80 -' --
c 60 --+-�-�- -- ---tJ-
c
CD
40
0. i
20
--
0 .L__ - . .
100 10 1 0.1 0.01
Grain Size, mm
ASSOCIATED EARTH SCIENCES, INC.
911 5th Ave., Suite 100 Kirkland, WA 98033 425-827-7701 FAX 425-827-5424