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Associated Earth Sciences, Inc,
Subsurface Exploration and
Geotechnical Engineering Report
HAZEN HIGH SCHOOL
ATHLETIC FIELD IMPROVEMENTS
Renton, Washington
Environmental Assessments and
Remediation
Sustainable Development Services
Geologic Assessments
Prepared for
D.A. Hogan & Associates, Inc.
Project No. KE080762A
January 29, 2009
Associated Earth Sciences, Inc.
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January 29, 2009
Project No. KE080762A
D.A. Hogan & Associates, Inc.
119 151 Avenue South, Suite 110
Seattle, Washington 98104
Attention: Mr. Eric Gold
Subject: Subsurface Exploration and
Geotechnical Engineering Report
Hazen 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
K*tD. Merriman, P.E.-
Principal Engineer
KDMltb
KE080762A2
Projec1s1200807621K FIW P
Kirkland Everett Tacoma
425-827-7701 425-259-0522 253-722-2992
www.aesgeo.com
SUBSURFACE EXPLORATION AND
GEOTECHNICAL ENGINEERING REPORT
HAZEN 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' Avenue, Suite 100
Kirkland, Washington 98033
425-827-7701
Fax: 425-827-5424
January 29, 2009
Project No. KE080762A
Subsurface Exploration and
Hazen 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 Hazen High School athletic field improvements in Renton, Washington.
The site location is shown on the "Vicinity Map," Figure 1. Existing and proposed site
features, and the approximate locations of the subsurface explorations referenced in this study
are presented on the "Site and Exploration Plan," Figure 2. This report is based on ' a plan
sheet by D.A. Hogan titled Lower Site Concept, HHS 2.0, dated November 13, 2008. 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 Scope
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 Hazen 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,
design of bleacher foundations, general recommendations for site drainage design, and
foundation design recommendations for new field lights. This report summarizes our current
fieldwork 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.
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Hazen High School Athletic Field Improvements Geotechnical Engineering Report
Renton, Washington Project and Site Conditions
2.0 PROJECT AND SITE DESCRIPTION
The project site includes the area of natural turf practice field on the northwest part of the site.
The project area is relatively level, with overall vertical relief visually estimated at less than 5
feet. The existing field appears to have been graded to its current configuration during past
earthwork on -site. The field is surrounded on the west, north, and east sides by trees and
adjacent properties, and to the south by another natural turf practice field and baseball field.
Proposed improvements include construction of a new synthetic -surfaced multi -purpose field.
Six new light poles will surround the field, and new bleachers will be constructed on the south
side. We anticipate that the new improvements will be constructed close to existing grades.
3.0 SITE EXPLORATION
We completed eight hollow -stem auger borings at the locations shown on Figure 2. The
borings were completed by advancing a 41/4-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
an engineering geologist 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 the Lower Site
Concept drawing that was provided to us. 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.
Disturbed but representative samples were obtained by using the modified Standard Penetration
Test (SPT) 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
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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 sampler 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 study, visual reconnaissance of the site, and a review of applicable geologic literature.
As shown on the field logs, our exploration borings generally encountered surficial fill,
underlain by native sediments consisting of interbedded medium dense sand and sand with silt,
and stiff silt.
4.1 Stratigraphy
Sod and Topsoil
Each of the borings encountered a surficial layer of sod.
Fill
All of the exploration borings encountered existing fill that was observed to range from Z to 8
feet thick at the boring locations. The existing fill varies in density, gradation, and organic
content. Significant organic content including coarser woody debris was observed in some
areas. The existing fill will present some challenges that are addressed in greater detail later in
this report. Excavated existing fill material should be 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 soil is dried to achieve suitable moisture content prior to
compaction.
Ice Contact Sediments
Below the existing fill, our exploration borings encountered variable interbedded sand, sand
with silt, and silt. Density typically varied from loose to medium dense, increasing to dense at
greater depths in five of the exploration borings completed for this study. These native
sediments are interpreted to represent Vashon ice contact sediments. Ice contact sediments
were initially deposited above or within a glacial ice mass, and were subsequently redeposited
when the ice melted. Ice contact sediments can be stratified and alluvially re -worked, and
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Hazen High School Athletic Field Improvements Geotechnical Engineering Report
Renton, Washington Project and Site Conditions
stratification was noted in our exploration borings on this site. Ice contact deposits are
typically not consolidated to the same degree as advance outwash and lodgement till sediments,
though some degree of compaction by glacial activity can occur. The ice contact sediments
observed in our exploration borings for this project are silty and are considered highly
moisture -sensitive. With proper preparation, the ice contact sediments will provide adequate
support for the new field surfacing, bleachers, and light poles. Excavated ice, contact
sediments are expected to be above optimum moisture content for compaction purposes, and
will need to be dried during favorable dry site and weather conditions to allow their reuse in
structural fill applications.
4.2 Laboratory Testing
We selected six of our exploration boring samples 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 contained in the Appendix. In
general, the grain -size analyses indicated that the existing fill and ice contact sediments contain
up to 90 percent silt. Therefore, existing soils are expected to have low permeability and to be
highly moisture -sensitive.
4.3 Hydrology
Six of the exploration borings encountered ground water seepage, typically originating from
granular horizons within the ice contact sediments. Ground water seepage was also
encountered within the existing fill in EB-6 and appeared to be perched above lower
permeability ice contact sediments at depths. 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.
4.4 Published Geologic Map
We reviewed a published geologic map of the area (Geologic Map of King County,
Washington, by Derek B. Booth, Kathy A. Troost, and Aaron P. Wisher, 2006). The
referenced map indicates that the site vicinity is characterized primarily by lodgement till at the
ground surface, with smaller areas of advance outwash nearby. The native sediments observed
in our explorations for this project are not consistent with this mapping. It is not unusual to
find localized areas that vary from published regional scale geologic mapping, and that is the
case with this site. Ice contact sediments occur regularly in the project area above lodgement
till. We recommend that design activities for this project be based on subsurface materials
observed in our on -site explorations, as well as laboratory testing included with this report.
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Renton, Washington Design Recommendations
11. DESIGN RECOMMENDATIONS
5.0 INTRODUCTION
It is our opinion that, from a geotechnical standpoint, the proposed field improvements,
bleachers, and new light poles are feasible provided that the recommendations contained herein
are properly followed. The existing fill and ice contact sediments are expected to have low
permeability, and therefore, an underdrain system for the new athletic field improvements is
warranted.
Up to 8 feet of existing fill was encountered in each exploration boring. Fill depth at the
location of the planned bleachers was observed to be 3 feet. It would be possible to provide
support for the bleachers without removing the existing fill, contingent on proper
implementation of the recommendations in this report. Light pole foundations should be
designed with lateral and vertical capacities that are applicable to the material in which they are
embedded. Fill depth at each light pole location is documented in the exploration logs attached
with this report. The existing athletic field is also underlain by existing fill that is expected to
be too thick to economically remove. This report provides geotechnical engineering
recommendations for support of the new field above the existing soils. Because some existing
fill will be left in place below the new field, some increased risk of future settlement will
result. This additional risk will be offset by substantial cost savings at the time of construction
as compared to removal and replacement of all of the existing fill. We are available to discuss
risks and benefits of different approaches to managing the existing fill soils.
6.0 EROSION HAZARDS AND MITIGATION
As of October 1, 2006, 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
(TESL) inspections for all sites 1 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. TESL 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 1
acre 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
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Renton, Washington Design Recommendations
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.
In order to meet the current Ecology requirements, a properly 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 I" 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. Ditchlswale 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
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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
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
swale/berm 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 Mitigation
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.
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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
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 balesisilt fences around pile perimeters. During the period between
October 15t and March 3I't, 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.
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7.0 SITE PREPARATION
We understand that new site grades will be similar to existing site grades, and approximately
the upper 1 foot of existing soil will be removed from the football field prior to constructing
the synthetic turf and associated subgrade. Site preparation for the renovated field and
bleacher 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
system, where planned, and bearing pads for the bleachers. 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 bleacher bearing pad 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 Ieast 1 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 at or over the optimum levels for achieving moisture compaction at the time of
our field exploration.
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 504X, or equivalent.
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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 up to 4 feet
tall or an engineered retaining wall. Rockeries should not be used to face fills unless the fills
are reinforced. Unsupported temporary cut slopes into the existing fill and ice contact
sediments should be made no steeper than 1.5H :1 V . 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 field and for 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
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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 athletic field, bleacher bearing pad, or pavement edges before sloping
down at a maximum angle of 2H:IV.
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
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 ice contact 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
and for the building pad, provided they are placed and compacted at a moisture content that
allows for the minimum specified compaction presented in this report. We anticipate that this
will require drying during favorable dry site and weather conditions prior to compaction.
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. 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 ice contact sediments. 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 (WSDOT) Standard Specifications for Road, Bridge and
Municipal Construction, Section 9-03.12(4), "Gravel Backfill for Drains," which freely
January 29, 2009 ASSOCIATED EARTH SCIENCES, INC.
BWG/tb - KE080762A2 - Projeas}200807621KEIWP Page I I
Subsurface Exploration and
Hazen High School Athletic Field Improvements Geolechnical Engineering Report
Renton, Washington Design Recommendations
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 ice contact sediments, which
vary from loose to very dense. The ice contact sediments will be more difficult to excavate
than the overlying fill soils, particularly where gravel and cobbles are present. Therefore, the
contractor should be prepared to encounter 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. The drainage aggregate is a
very specialized manufactured 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.
9.0 BLEACHER BEARING PADS
Existing fill soils in the area of the proposed bleachers was observed to be approximately 3 feet
thick. The "Site Preparation" section of this report provides recommendations for
recompacting and performance testing (proof -rolling) the existing fill prior to construction of
bleacher bearing pads. This will result in existing fill remaining below the bearing pads, and a
corresponding risk of future settlement. If such risk is not acceptable, all of the existing fill
should be removed and replaced with Structural Fill as defined in this report. Typically,
bleachers would be relatively easy to re -level, and if re-Ieveling is ever needed, the associated
costs would likely be less than the initial cost of removal of all of the existing fill and
January 29, 2009 ASSOCIATED EARTH SCIENCES, INC.
EWG/1b - KE080762A2 - Projects12"07621KE1WP Page 12
Subsurface Exploration and
Hazen High School Athletic Field Improvements Geotechnical Engineering Report
Renton, Washington Design Recommendations
replacement with new structural fill. We are available to discuss risks and benefits of
constructing bleacher bearing pads above existing fill, and approximate anticipated costs of
removal and replacement of the existing fill.
We recommend that an allowable bearing pressure of 1,500 pounds per square foot (psf) be
utilized for near -surface bleacher bearing pads if founded on existing fill soils prepared under
the observation of AESI and in accordance with the "Site Preparation" section of this report.
An increase of one-third may be used for short-term wind or seismic loading. It should be
noted that the area bounded by lines extending downward at 1H:1V from any bearing pad must
not intersect another footing or intersect a filled area that has not been compacted to at least 95
percent of ASTM : D 1557, In addition, a 1.5H :1 V line extending down from any bearing pad
must not daylight because sloughing or raveling may eventually undermine the footing. Thus,
footings should not be placed near the edge of steps or cuts in the bearing soils.
Anticipated settlement of bearing pads founded above existing fill prepared as recommended in
this report should be on the order of 1 to 2 inches. However, disturbed soil not removed from
footing excavations prior to footing placement could result in increased settlements. All
footing areas should be inspected by AESI prior to placing concrete to verify that the design
bearing capacity of the soils has been attained and that construction conforms to the
recommendations contained in this report. The City of Renton may require such inspections.
9.1 Ground Motion
Structural design of the project should follow 2006 International Building Code (IBC)
standards using Site Class "C". 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 sites using the USGS software utility Seismic Hazard Curves and
Uniform Response Spectra. The USGS software interpolated ground motions at the project
sites as follows for periods of 0.2 and 1.0 seconds, respectively, with a 2 percent chance of
exceedence in 50 years: Ss = 1.404, Si = 0.478.
10.0 LIGHT POLE FOUNDATIONS
10.1 Compressive Capacities
We anticipate that the depth of existing fill will vary substantially at different proposed light
pole locations. For example, exploration boring EB-1 was completed at the location of the
planned northwest light pole and encountered existing fill above native soil at a depth of 7 feet.
Exploration boring EB-3 was completed at the location of the planned southwest light pole and
encountered 2 feet of existing fill above the native soils. For this project, we anticipate that
January 29, 2009 ASSOCIATED EARTH SCIENCES, INC.
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Subsurface Exploration and
Hazen High School Athletic Field Improvements Geotechnical Engineering Report
Renton, Washington Design Recommendations
lateral capacities will be the most critical design factor for the light pole foundations, and will
likely exert the most control over the depth of embedment. It would be feasible to install light
poles 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 shafts of the poles, as described below. For those poles
that extend at least 5 feet into undisturbed native sediments, an allowable end -bearing capacity
of 3 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 psf for the existing fill and 350 psf for the
underlying native sediments 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 light pole or 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 embedded length in inches and "T" is the relative
stiffness factor. The relative stiffness factor for the pier (T) should be computed by:
T = EI
nh
where: E = modulus of elasticity (pounds per square inch [psi])
I = moment of inertia (in)
m = 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 "nh" for the soil observed on this site are presented
subsequently. Piers with an L1T 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
an L/T ratio greater than 3, the modulus of subgrade reaction method is typically used. Both
of these methods are discussed below.
January 29. 2009 ASSOCIATED EARTH SCIENCES, INC.
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Subsurface Exploration and
Hazen High School Athletic Field Improvements Geotechnical Engineering Report
Renton, Washington Design Recommendations
Modulus of Subgrade 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 Kh = (nh)(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 (nh) of 70 pci for native soils and 30 pci for existing fill soils.
Passive Pressure Method
Lateral loads on the piers, caused by seismic or transient loading conditions, may be resisted
by passive soil pressure against the pier shaft. An allowable passive earth pressure of 200
pounds per cubic foot (pcf), expressed as an equivalent fluid unit weight, may be used for that
portion of the foundation embedded within medium dense/stiff native soils. Below a depth of 2
feet in existing 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 piers, 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 constant at a depths 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 in
the existing fill and ice contact sediments. 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
earthwork and foundation recommendations may be properly interpreted and implemented in
the design.
January 29, 2009 ASSOCIATED EARTH SCIENCES, INC.
B WG/rb - K£080762A2 - Projecrs12"0762WDWP Page 15
Subsurface Exploration and
Hazen High School Athletic Field Improvements Geotechnical Engineering Report
Renton, Washington Design Recommendations
We are also available to provide geotechnical engineering and monitoring services during
construction. The integrity of the athletic fields, light poles, and structure 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
Bruce W. Guenzler, P.E.G.
Project Geologist
Attachments: Figure 1: Vicinity Map
Figure 2: Site and Exploration Plan
Appendix: Exploration Logs
Laboratory Results
Kurt D. Merriman, P.E.
Principal Engineer
January 29, 2009 ASSOCIATED EARTH SCIENCES, INC.
BWGAb - KE080762A2 - Pr0jeC1S1200807452lKEIWP Page 16
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APPENDIX
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Well -graded gravel and
Terms Describing Relative Density and Consistency
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�, G- Grain Size
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M = Moisture Content
Consistency SPT"llalowslfoot A = Atterberg Lrrtits
m
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gravel with sand
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m
m m
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clayey gravel with sand
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Component Definitions
Well -graded sand and
0
Descriptive Tenn_ Size Range and Sieve Number
S
sand with gravel, little
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Z
Coarse Sand No. 4 (4.75 mm) to No. 10 (2.00 mm)
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Medium Sand No. 10 (2.00 mm) to No. 40 (0.425 mm)
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gravel
Silt and Clay Smaller than Na. 200 (0.475 min)
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Clayey sand and
(a) Estimated Percentage Moisture Content
clayey sand with gravel
Percentage by Dry - Absence of moisture,
Component Weight dusty, dry to the touch
Trace c5 Slightly Moist- Perceptible
Silt, sandy silt, gravelly sift,
ML
silt with sand or gravel
Few 5 to 10 moisture
,�„
little 15 to 25 Moist - Damp but no visible
m
to
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With - Nan -primary coarse water
Clay of low to medium
o
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constituents: > 15% Very Moist - Water visible but
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plasticity, silty, sandy, or
- Fines content between not free draining
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gravelly clay, lean clay
5% and 15% Wet - Visible free water, usual N
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from below water table
a=
Organic clay or silt of low
Symbols
m
a
— —
t7L
plasticity
BlowslTor
0
_ __
Sampler portion of 5'
Cement grod
Type
surface seal
Elastic silt, clayey sift, silt
2 OD Sampler Type
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with micaceous or
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diatomaceous fine sand or
silt
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blank caning
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Clay of high plasticity,
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sandy or gravelly Clay, fat
Bulk sample 3.0' OD Thin -Wall Tube Sampler
section
-' Screened casing
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clay with sand or gravel
{including Shelby tube)
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—
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lh itter pack
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O Portion not recovered
.• End Cap
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Organic clay or silt of
U.
off
medium to high
is
Percentage by dry weight {al Depth of ground water
f ff��/
plasticity
M (SPT) standard Penetration Test
(ASTM D 1586) 1 D AT — At time of drilling
rfi g Static water level (date)
In General Accordance with
a
ra o
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N
0
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highly organic soils
Standard Practice for Description Combined USCS symbols used for
=
6
and Identification of Soils (ASTM D-2488) fines between 5% and i 5%
Classifications of soils in this report are based on visual field and/or laboratory observations, which include density/consistency, moisture condition, grain she, and
plasticity estimates and should not be comtrued to imply field or laboratory testing unless presented herein. Visual.manual and/or laboratory classification
methods of ASTM D-2487 and i)-2488 were used as an identification guide for the Untried Soll Classification System.
Associated Earth Sciences, Inc.
o MV�A EXPLORATION LOG KEY FIGURE Al
am'a
Associated Earth Sciences, Inc.
Exploration Log
Project Number
Exploration Number
Sheet
KE080762A
EB-1
1 of 1
Project Name Hazen Hiah School Ground Surface Elevation (ft)
Location Renton, WA Datum NIA
DrillerlEquipment Boretec Track Drill Date Start/Finish 12L3CM.,1220108
Hammer Weight/Drop 140# 1 30" Hole Diameter (in) 7"
m
03
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DESCRIPTION
5
10 20 30 40
°
S-1
Fill
Sod over 11" loose, moist, brown, fine to medium SAND, trace silt. —
3
4
9
Loose, moist, dark brown, silty SAND, with scattered organics.
5
S 2
11
12
�24
Becomes medium dense, gray to tan, silty fine to medium SAND, trace
12
gravel.
5
Stiff, moist to wet, dark brown, fine sandy SILT, with scattered cinders and
6
S-3
organic debris.
5
11
6
_.——— — — — — — —
Ice Contact Sediments
S 4
Stiff, wet, gray, with iron oxide stains, SILT, with fine sand.
2
4
g
5
10
Medium dense, moist, gray -brown, with heavy iron oxide stains, bedded
7
S-5
silty fine to medium SAND, few gravel, clean sand layer at i V,
13
30
17
S-6
Becomes very dense.
10
29
65
36
15
Bottom of exploration boring at 14 feet
No ground water at time of drilling.
20
25
30
35
Sampler Type (ST):
m 2" OD Split Spoon Sampler (SPT) No Recovery M - Moisture Logged by: EJL
Y OD Split Spoon Sampler (D & M) Ring Sample _V_ Water Level() Approved by:
® Grab Sample Shelby Tube Sample i Water Level at time of drilling (ATD)
Associated Earth Sciences, Inc.
Exploration Log
Al
Project Number
Exploration Number Sheet
KEO80762A
EB-2 1 of 1
Project Name Hazen High School Ground Surface Elevation (ft)
Location Renton, WA Datum KI/A
_
Driller/Equipment Boretec Track Drill Date StartlFinish IMOMR 12/30/08
Hammer Weight/Drop 140# 130" Hole Diameter (in) 71,
a
C
N
BjOWS/FOdt
N
rn
m
S R
E
o
T
DESCRIPTION
0
"
En
°
10 20 30 40
S-1
Fill
Sod over 12" loose, moist, red -brown, fine to medium, some coarse SAND,
6
11
trace silt,
10
6" medium dense, moist, dark brown, silty SAND to sandy SILT, scattered
�arganic debris over 6" SAND, trace silt. ! r
10
S-2
11
a ium dense, moist, (larkbrown, sly , sca ere saddTayers.
5
5
Ice Contact Sediments
S-3
Medium dense, wet to saturated, mottled gray, thinly bedded, silty fine
s
Al!
SAND to fine sandy SILT.
7
8
S-4
Becomes wet, light brown, silty very fine SAND.
g
13
i
8
15
10
S-5
Becomes dense, scattered iron oxide stains, thinly bedded.
8
13
31
18
---
Bottom of exploration boring at 11.5 feet
Ground water seepage at 6' 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
Y OD Split Spoon Sampler (D & M) Ring Sample Q Water Level() Approved by:
® Grab Sample Q Shelby Tube Sample 1 Water Level at time of drilling (ATD)
Associated Eartb Sciences, Inc.
Exploration Log
Project Number Exploration Number
Sheet
KE080762A EB-3
1 of 1
Project Name Hazen High School Ground Surface Elevation (ft)
Location Renton, WA Datum NIA
Driller/Equipment Boretec Track Drill Date StartiFinish 1?130108 19/19/30108
Hammer WeighUDrop 140# /_ 3_011 _ Hole Diameter (in) 7"
$
N
n
U
0- -6E
,O
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Blows/Foot
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$ E
10
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DESCRIPTION
"
3
°
10 20 30 40
S 1
Fill
Sod over 10" loose, moist, brown, SAND, trace sift over 5" medium dense,
3
6
A112
moist, red -brown, silty SAND, with gravel, scattered debris over medium
6
dense, moist, brown, SAND, trace silt.
-------------------------------
Ice Contact Sediments
6
S-2
Stiff, moist, light brown, with mottling, SILT, trace fine sand,
7
Al
a
5
Becomes wet to saturated, thinly bedded, silty very fine SAND.
5
S 3
T_
5
♦12
7
S-4
Becomes moist_
6
10
21
i1
10
S 5
Becomes wet with thin orange interbeds.
6
`
8
12
16
Bottom of exploration boring at 11.5 feet
Slight seepage at 6' and 1 Vat 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 & tut) U Ring Sample V Water Level() Approved by:
® Grab Sample Z Shelby Tube Sample Y Water Level at time of drilling (ATD)
Associated Earth Sciences, Inc.
Exploration Log
❑
Project Number
Exploration Number
Sheet
KE080762A
EB-4
1 of 1
Project Name Hazen High School Ground Surface Elevation (ft)
Location Renton. WA Datum NZA
_T
Driller/Equipment Boretec Track Drill Date Start/Finish 12rinlnR 1mo ns
Hammer Weight/Drop 14 # ! Hole Diameter (in) 71,
v
-
Blows/Foot
a
S E
T
2 Tfl
��
`y
o
to
DESCRIPTION
0
�
m
°
10 20 30 40
S-1
Fill
Sod over 12" loose, moist, brown, fine to medium SAND, trace sift over 3"
7
•
7
silty SAND over medium dense, moist, brown, fine to medium SAND, trace
10
silt.
S-2
10 13
A2
6" layer of very stiff, light brown, SILT, with fine sand over orange, moist,
12
fine to medium SAND, trace silt.
5
Ice Contact Sediments
S
S_3
Medium dense, wet to saturated, light brown, thinly bedded, silty fine SAND
1a
` 22
to fine sandy SILT, with scattered coarse sand lenses.
12
S-4
Becomes gray, with very stiff SILT layer at 8 112'.
6
♦
7
10
Bottom of exploration boring at 9 feet
Slight seepage at 6'; B'; and 9'.
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 O Approved by:
® Grab Sample Z Shelby Tube Sample -T Water Level at time of drilling (ATD)
Associated Earth Sciences, Inc.
Exploration Log
Yys,
i
Project Number Exploration Number
Sheet
KE080762A EB-5
1 of 1
Project Name Hazen High School Ground Surface Elevation (ft)
Location Renton. WA Datum NA
Driller/Equipment Boretec Track Drill Date Start/Finish
Hammer Weight/Drop 140# / 30" Hole Diameter (in) 7"
L
°
U —
c
D
— ID
a�
7
-
=
N
Blows/Foot
N
En
cu
S E
1O i
E
o
`m
T
CD rn
DESCRIPTION
o
CU
m
10 20 30 40
L
°
S-1
Fill
Sod over 11" loose, moist, brown, fine to medium SAND, trace silt over 3"
3
4
10
silty SAND, few gravel layer, over fine to medium SAND, trace silt.
6
S-2
Loose, wet, black to brown, silty SAND, with abundant cinders, wood
3
•
debris, scattered organics.
3
4
5
T�
5
Ice Contact Sediments
S-3
Medium dense, wet, green -gray, silty SAND, with interbedded sandy silt.
6
A14
6
S-4
Medium dense, moist, orange -brown, fine to medium SAND, trace to few
6
s
20
silt.
14
Becomes dense, brown, silty fine to coarse SAND, few gravel, with sand,
g
S-5
with silt layer.
12
A32
20
Bottom of exploration boring at 11.5 feet
Slight seepage at 5' 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) Fling Sample Q Water Level() Approved by:
® Grab Sample Z Shelby Tube Sample 1 Water Level at time of drilling (ATD)
Associated Earth Sciences, Inc.
Exploration Lo
Project Number
Exploration Number
Sheet
LIN` }„
KE080762A
E$-6
1 of 1
Project Name Hazen High School Ground Surface Elevation (ft)
Location Renton WA Datum NIA
Driller/Equipment Boretec Track Drill Date StarUFinish 1121Rr11f]R 1714f11r1R
Hammer Weight/Drop 140# / 30" Hole Diameter (in) 7"
?
a
= 4
rL
m
W
�
SoCA
y
Blows/Foot
Q
S E
T 5.
p�,
}
D
ay
o
T Um)
C7 N
DESCRIPTION
o
"
ra
m
10 20 30 40
a
S-1
Fill
Sod over 8" loose, wet, silty SAND, with rootlets, over 3" layer of fine to
3
4
A111
medium SAND, trace silt, over silty SAND, few gravel.
7
S 2
Soft, wet, dark gray, sandy SILT, with scattered cinders and organics.
2
.
2
1
3
5
_ _ Vashon Recessional Lacustrine?
S-3
Loose, saturated, gray with mottling, silty very fine SAND.
4
. fi
3
3
Medium dense, moist, brown, silty SAND, few gravel, interbedded with
6
S-4
SAND, with silt lenses.
7
A
7
10
10
7
S-5
—
11
A24
13
-
Bottom of exploration boring at 11.5 feel
Ground water seepage at 4' 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 7 Water Level() Approved by:
5 Grab Sample Shelby Tube Sample i Water Level at time of drilling (ATD)
Associated Earth Sciences, Inc.
Exploration Loci
-.:
Project Number
Exploration Number
Sheet
KE080762A
EB-7
1 of 1
Project Name Hazen High School Ground Surface Elevation (ft)
Location Renton WA Datum N/A
DrillerlEquipment Boretec Track Drill Date StarUFinish 1919olog i moms
Hammer Weight/Drop 140# 130" Hale Diameter (in) 7"
en
�
G
U7
y
J
N
Blows/Foot
�
F-
n
S E
2a
3:E'U
o
iu
T ,
0(o
DESCRIPTION
U
�
10 20 30 40
D
S-1
Fill
Sod over loose, moist, brown, silty SAND, with gravel, scattered brick,
3
6
9
asphalt pieces.
3
Medium dense, moist, orange -brown, Inc to medium SAND, trace silt.
S-2
8
9
Ala
Ice Contact Sediments
Medium dense, moist, light brown, silty SAND, few gravel, with silt layer.
s
5
Grades to blue -gray, silty SAND, trace gravel.
12
S-3
14
30
16
S-4
Becomes dense, silty fine SAND to fine sandy SILT.
11
18
A43
25
10
Bottom of exploration boring at 9 Feet
No ground water observed at time of drilling_
15
20
25
30
35
Sampler Type (ST):
m 2- OD Split Spoon Sampler (SPT) a No Recovery M - Moisture Logged by: EJL
m 3" OD Split Spoon Sampler (0 & M) Ring Sample Q Water Level() Approved by:
® Grab Sample Shelby Tube Sample 1 Water Level at time of drilling (ATD)
Associated Earth Sciences, Inc.
Exploration Loci
Project Number Exploration Number
Sheet
KE080762A EB-8
1 of 1
Project Name Hazen High School Ground Surface Elevation (ft)
Location Renton, WA Datum NIA
Driller/Equipment Boretec Track Drill Date Start/Finish 12111(}MR 171S0109
Hammer Weight/Drop 140# ! 30" Hole Diameter (in)
Vl
U O
C
.O
CJ
'a
N
CD
J
tD
N
Blows/Foot
N
N
n
o
S E
T
`�a
0 cO
o
U
i�
o
m
m
r
DESCRIPTION
10 20 30 40
°
5 1
Fill
Loose, moist, dark brown, silty SAND, few gravel, scattered cinder, wood,
3
5
20
brick pieces.
15
Medium dense, moist, green -gray, fine to medium SAND, few silt,
scattered silt lenses.
10
S-2
1Medium dense, wet, dark brown, silty SAND, few gravel.
13
ik3l
Ice Contact Sediments
18
Dense, moist, orange -brown, fine to medium SAND, few silt; interbedded
5
silt lenses.
10
S-3
Becomes wet, brown with iron oxide stains, bedded fine sand, few silt to
14
AZ8
silty.
Becomes saturated, gray, silty very fine SAND,
14
S-4
Becomes moist.
7
9
z
16
10
Becomes dense, silty very fine SAND to fine sandy SILT.
10
S 5
16
-
3
20
Bottum of exploration boring at 11.5 feet
Slight seepage at 6' 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) 1] Ring Sample 7 Water Level() Approved by:
® Grab Sample P1 Shelby Tube Sample 1 Water Level at time of drilling (ATD)
GRAIN SIZE ANALYSIS - MECHANICAL
Date
1/23/2009
Project
Hazen High School
Tested By
BG
Location
Wt, of moisture wet sample + Tall
912.37
Wt. of moisture dry
Sample + Tare
808.92
Wt. of Tare
219.1
Wt. of moisture Dry
Sample
589.82
Moisture %
18%
Project No.
KE080762A
EB/EP No IDepth
EB-1 2.5'
Total Sample Tare
Total Sample wt + tare
Total Sample Wt
Soil Description
Silty fine sand
219.1
Soecification Reauirements
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
3/8
9.51
26.27
4.45
95.55
#4
4.76
33-56
5-69
94.31
#8
2.38
41-21
6.99
93.01
#10
2
43.02
7.29
92.71
#20
0.85
51.58
8.75
91.25
#40
0.42
81.88
13.88
86.12
#60
0.25
194.03
32.90
67.10
#100
1 0.149
289.26
49.04
50.96
#200
0.074
1 318.14
1 53.94
1 46.06
100
80
m
60
ii
c
v
y 40
a.
20
US STANDARD SIEVE NOS.
3" 314" NO.4 NO.16 N0.40 NO.200
100 10 1 0.1 0.01
Grain Size, mrn
ASSOCIATED EARTH SCIENCES, INC.
911 5th Ave„ Suite 100 Kirkland, WA 98033 425-827-7701 FAX 425-827-5424
GRAIN SIZE ANALYSIS - MECHANICAL
Date
Project
Project No.
Soil Description
1/2312009
Hazen High School
KE080762A
Silt w/trace fine sand
Tested By
Location
EB/EP No
Depth
BG
EB-3
2.5'
Wt. of moisture wet sample + Tall
901.33
Total Sample Tare
390.74
Wt. of moisture dry Sam le + Tare
800.37
Total Sample wt + tare
901.33
Wt. of Tare
390.74
Total Sample Wt
510.6
Wt. of moisture Dry
Sample
409.63
Total Sample Dry Wt
Moisture %
25%
Seecification Reauirements
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
3/4
19
0
-
100.00
3/8
9.51
0
-
100.00
#4
4.76
0
-
100.00
#8
2.38
0.05
0.01
99.99
#10
2
0.06
0.01
99.99
#20
0.85
0.55
0.13
99.87
#40
0.42
2.01
0.49
99.51
#60
025
3.95 1
0.96
99.04
#100
0.149
8.23
2.01
97.99
#200
0.074
36.23
8.84
91.16
US STANDARD SIEVE NOS.
3" 3/4" NO.4 NO.16 NO.40 NO.200
-
'�
1
+
60LL
-
F
Q}
{
40
CL
0i .
100 10 1
Grain Size, mm
iIj
0.1 0.01
ASSOCIATED EARTH SCIENCES, INC.
911 5th Ave., Suite 100 Kirkland, wA 98033 425-827-7701 FAX 425-827-5424
GRAIN SIZE ANALYSIS - MECHANICAL
Date Project
1/23/2009 Hazen High School
Tested By Location
BG
Wt. of moisture wet sample + Tel
Wt. of moisture dry Sample + Tare
Wt. of Tare
Wt. of moisture Dry Sample
Moisture %
Project No.
KE080762A
EBlEP No
EB-4
Depth
12.5'
705.37
Total Sample Tare
633.97
Total Sample wt + tar
226.04
Total Sample Wt
407.93
Total Sample Dry Wt
18%
Soil Description
Silt wl fine sand
226.04
5nac1firAtinn RAn:drPrn P_ntS
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
0
-
100.00
#4
4.76
0.29
0.07
99.93
#8
2.38
0.64
0.16
99.84
#10
2
0.97
0.24
99.76
#20
0.85
2.29
0.56
99-44
#40
0.42
17.25
4.23
95.77
#60
0.25
85.33
20.92
79.08
#100
0.149
160.07
1 39.24
1 60.76
#200
1 0.074
203.78
1 49.95
1 50.05
100
80
60
C
LL
C
d
y 40
a
20
0
100
US STANDARD SIEVE NOS.
3" 314" N0.4 NOA6 NO 40
NO 200
�
i
i
i
I
_
r._.I
-- ,
-
- --
_.l
_ 4444
rI
I
10 1 0.1
Grain Size, mm
ASSOCIATED EARTH SCIENCES, INC.
911 5th Ave., Suite 100 Kirkland, WA 98033 425-827-7701 FAX 425-827-5424
0.01
GRAIN SIZE ANALYSIS - MECHANICAL
Date
1123/2009
Project
Hazen High School
Tested By
BG
Location
Wt. of moisture wet sample + Tar
790A1
Wt. of moisture dry
Sample + Tare
669.82
Wt. of Tare
100.56
Wt. of moisture Dry
Sample
569.26
Moisture %
21 %
Project No.
KE080762A
EB1EP No Depth
EB-i 1 5'
Total Sample Tare
Total Sample wt + tare
Soil Description
Silt wl fine sand
100.56
.1;narifiratinn RPmiirPmPnlc
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
0
-
100.00
#4
4.76
0
-
100.00
#8
2.38
0.43
0.08
99.92
#10
2
0.95
0.17
99.83
#20
0,85
3.92
0,69
99.31
#40
0.42
13.31
2.34
97.66
#60
0.25
1 119.5
20.99
1 79.01
#100
0.149
191.49
33.64
66.36
#200
0.074
224.39
39.42
60-58
US STANDARD SIEVE NOS.
3" 314" NO.4 NO.16 NO.40 NO.200
100
80
20
0
100 10 1 0.1
Grain Size, mm
ASSOCIATED EARTH SCIENCES, INC.
911 5th Ave., Suite 100 Kirkland, WA 98033 425-827-7701 FAX 425-827-5424
0.01
GRAIN SIZE ANALYSIS - MECHANICAL
Date
1/23/2009
Project
Hazen High School
Project No.
KE080762A
Soil Description
Silty Sand with Gravel
Tested By
BG
Location
EB/EP No
EB-5
Depth
12.5'
Wt. of moisture wet sample + Tai
1180.25
Total Sample Tare
297.52
Wt. of moisture dry Sample + Tare
913.17
Total Sample wt + tare
1180.25
Wt. of Tare
297.52
Total Sample Wt
8 .7
Wt. of moisture D
Sample
615.65
Total Sample Dry Wt
615.7
Moisture %
43%
5necifiration 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
1
25.4
0
-
100.00
314
19
14.66
2.38
97.62
3/8
9.51
56.48
9.17
90.83
#4
4.76
84.7
13.76
86.24
#8
2.38
112.54
18.28
81.72
#10
2
120.6
19.59
80.41
#20
0.85
152.64
24.79
75.21
#40
0.42
187.85
30.51
69.49
#60 1
0.25
233.99
38.01
61.99
#100
0.149
287.85
1 46.76
53.24
9200
0.074
330.94
1 53.75
46.25
US STANDARD SIEVE NOS.
3" 314- NO.4 NO.16 NO.40
100
80
60 --
C
C
40
IL
20
NO.200
OI _ 1 _,IJ..._l_J_. �.e 1._,... -
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 425-827.6424
GRAIN SIZE ANALYSIS - MECHANICAL
Date
1/2312009
Project
Hazen High School
Tested By
BG
Location
Wt. of moisture wet sample + Tai
553.55
Wt. of moisture dry
Sample + Tare
477.14
Wt. of Tare
101.34
Wt. of moisture Dry
Sample
375.8
Moisture %
20%
Project No.
KE080762A
EB/EP No Depth
EB-8 13'
Total Sample Tare
Total Sample wt + tare
Total Sample Wt
Total Sample Dry Wt
Soil Description
Silty fine sand
101.34
SnP.rificatinn RPnidraments
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
3/4
19
0
-
100.00
3/8
9.51
0
-
100.00
#4
4.76
0.84
0.22
99.78
#8
2.38
1.44
0.38
99.62
##10
2
1.68
0.45
99.55
##20
0.85
3.41
0.91
99.09
##40
0.42
7.34
1.95
98.05
##60
025
100.72 J
26.80
1 73.20
#100
0.149
180.77
48.10
1 51.90
#200
0.074
218.81
58.23
41.77
100
80
�_ 60
LL
C
V
40
IL
20
US STANDARD SIEVE NOS.
3" 3/4" No.4 NO.16 NO.40
NO.200
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