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Associated Earth Sciences, Inc.
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P (425) 827 7701
Subsurface Exploration, Geologic Hazard, and
Preliminary Geotechnical Engineering Report
LINDBERGH HIGH SCHOOL ADDITIONS
Renton, Washington
Prepared For:
RENTON SCHOOL DISTRICT NO. 403
Project No. 20000669E005
October 1, 2021
Kirkland | Tacoma | Mount Vernon
425-827-7701 | www.aesgeo.com
October 1, 2021
Project No. 20000669E005
Renton School District No. 403
7812 South 124th Street
Seattle, Washington 98178
Attention: Mr. Stewart Shusterman
Subject: Subsurface Exploration, Geologic Hazard,
and Preliminary Geotechnical Engineering Report
Lindbergh High School Additions
16426 128th Avenue SE
Renton, Washington
Dear Mr. Shusterman:
We are pleased to present the enclosed copy of the referenced report. This report summarizes
the results of tasks including subsurface exploration, geologic hazard analysis, and preliminary
geotechnical engineering and offers preliminary recommendations for design of the project.
We have enjoyed working with you on this study and are confident that the preliminary
recommendations presented in this report will aid in the successful completion of your project.
Please contact me if you have any questions or if we can be of additional help to you.
Sincerely,
ASSOCIATED EARTH SCIENCES, INC.
Kirkland, Washington
______________________________
Bruce W. Guenzler, L.E.G.
Senior Associate Geologist
BWG/ld - 20000669E005-003
SUBSURFACE EXPLORATION, GEOLOGIC HAZARD, AND
PRELIMINARY GEOTECHNICAL ENGINEERING REPORT
LINDBERGH HIGH SCHOOL ADDITIONS
Renton, Washington
Prepared for:
Renton School District No. 403
7812 South 124th Street
Seattle, Washington 98178
Prepared by:
Associated Earth Sciences, Inc.
911 5th Avenue
Kirkland, Washington 98033
425-827-7701
October 1, 2021
Project No. 20000669E005
Subsurface Exploration, Geologic Hazard,
Lindbergh High School Additions and Preliminary Geotechnical Engineering Report
Renton, Washington Project and Site Conditions
October 1, 2021 ASSOCIATED EARTH SCIENCES, INC.
ART/ld - 20000669E005-003 Page 1
I.PROJECT AND SITE CONDITIONS
1.0 INTRODUCTION
This report presents the results of Associated Earth Sciences, Inc.’s (AESI’s) subsurface
exploration, geologic hazard analysis, and preliminary geotechnical engineering study for the
proposed building additions to Lindbergh High School in Renton, Washington. Our
recommendations are preliminary in that the project is in the early design phase. The site location
is shown on the “Vicinity Map,” Figure 1. The approximate locations of explorations completed
for this study are shown on the “Existing Site and Exploration Plan,” Figure 2. Interpretive
exploration logs of subsurface explorations completed for this study are included in Appendix A.
1.1 Purpose and Scope
The purpose of this study is to provide subsurface soil and groundwater data to be utilized in the
preliminary design of the Lindbergh High School additions project. Our study included reviewing
selected available geologic literature, advancing three exploration borings (EB-1 through EB-3),
advancing two hand-auger borings (HB-1 and HB-2), reviewing three previous AESI geotechnical
engineering studies (2003, 2004, and 2010) done in support of earlier projects on campus, and
performing a geologic study of subsurface sediment and groundwater conditions. Geotechnical
engineering studies were completed to formulate our recommendations for site preparation,
earthwork, the type of suitable foundations and floor slabs, allowable foundation soil bearing
pressures, anticipated foundation settlements, erosion considerations, and drainage
considerations. This report summarizes our current fieldwork and offers preliminary design
recommendations based on our present understanding of the project.
1.2 Authorization
Authorization to proceed with this study was given to AESI by means of District Purchase Order
2012000181 dated August 18, 2021. Our study was accomplished in general accordance with our
proposal, dated August 10, 2021. This report has been prepared for the exclusive use of Renton
School District and its 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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2.0 PROJECT AND SITE DESCRIPTION
The project site is that of the existing Lindbergh High School. The proposed project areas are
relatively flat and were graded to the existing configuration during previous earthwork
completed to construct the existing campus. Topography of the project vicinity is characterized
by an upland plateau with gentle to moderate slopes. A review of mapped critical areas on King
County iMAP shows that an undeveloped area along the southeast edge of the project site is
flagged as a potential seismic hazard area. No other geotechnical critical areas are flagged on or
immediately adjacent to the site. It appears unlikely that building additions constructed near the
newly completed explorations will need to address geotechnical critical areas requirements.
The proposed project will include substantial renovations and a building addition to the existing
Lincoln House in the northeast part of the site. An addition is proposed to be completed
southwest of the existing commons. Lastly, an interior courtyard in the science wing will be
infilled.
2.1 Historical Geotechnical Work
AESI had previously provided geotechnical engineering for twelve projects onsite. Three of the
previous studies included subsurface explorations near the currently proposed building
improvement areas. Previous subsurface explorations onsite by AESI generally encountered
surficial loose existing fill typically up to about 9 feet thick, underlain by very dense lodgement
till. In general, loose existing fill is not suitable for structural support, and dense lodgement till is
suitable for structural support with proper preparation. With respect to stormwater infiltration
potential, existing fill is not permitted to serve as an infiltration receptor, and lodgement till is
not a suitable infiltration receptor due to low permeability. This report relies, in part, on selected
subsurface data from previous AESI geotechnical engineering studies onsite. Where we used
existing data exploration locations are shown on the “Existing Site and Exploration Plan,
Figure 2,” and copies of exploration logs are included in Appendix A. Subsurface data from
previous AESI studies onsite included many additional explorations outside of the current work
areas, and those more distant explorations are not shown on Figure 2 or included in Appendix A.
3.0 SITE EXPLORATION
Our most recent field investigation for the current study was conducted in September 2021 and
included advancing three exploration borings and two hand-auger borings. This study is
supplemented with subsurface information gathered from our previous reports dated 2003,
2004, and 2010. The existing site conditions, and the approximate locations of subsurface
explorations referenced in this study are presented on the “Existing Site and Exploration Plan”
(Figure 2). The various types of sediments, as well as the depths where the characteristics of the
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Lindbergh High School Additions and Preliminary Geotechnical Engineering Report
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sediments changed, are indicated on the exploration logs presented in Appendix A. The depths
indicated on the logs where conditions changed may represent gradational variations between
sediment types. If changes occurred between sample intervals in our exploration borings, they
were interpreted. Our explorations were approximately located in the field by measuring from
known site features depicted on the aerial photograph used as a basis for Figure 2.
The conclusions and recommendations presented in this report are based, in part, on the
explorations completed for this study and previous on-site studies completed by AESI. The
number, locations, and depths of the explorations were completed within site and budgetary
constraints. Because of the nature of exploratory work below ground, extrapolation of
subsurface conditions between field explorations is necessary. It should be noted that differing
subsurface conditions may be present due to the random nature of deposition and the alteration
of topography by past grading and/or filling. The nature and extent of variations between the
field explorations may not become fully evident until construction. If variations are observed at
that time, it may be necessary to re-evaluate specific recommendations in this report and make
appropriate changes.
3.1 Exploration Borings
For this study, the three exploration borings were completed by advancing a 3.25-inch,
inside-diameter, hollow-stem auger using a track-mounted drill. During the drilling process,
samples were generally obtained at 2½- to 5-foot-depth intervals. The borings were continuously
observed and logged by a geologist from our firm. The exploration logs presented in Appendix A
are based on the field logs, drilling action, and visual observation of the samples collected.
Disturbed, but representative samples were obtained by using the Standard Penetration Test
(SPT) procedure in accordance with ASTM International (ASTM) D-1586. This test and sampling
method consists of driving a standard 2-inch, outside-diameter, split-barrel sampler a distance of
18 inches into the soil with a 140-pound hammer free-falling a distance of 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 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.
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4.0 SUBSURFACE CONDITIONS
4.1 Regional Geology and Soils Mapping
Published geologic mapping for the site and immediate vicinity were reviewed on the United
States Geological Survey (USGS) National Geologic Map Database1 , and on the Washington State
Department of Natural Resources (DNR) Geologic Information Portal 2. These published regional
geologic maps indicate that the site is underlain at shallow depths by Vashon lodgement till.
Lodgement till sediments are suitable for support of moderate to heavily loaded structures with
normal preparation but are not suitable for use as an infiltration receptor for collected
stormwater. Subsurface conditions observed in explorations for this study were generally
consistent with the referenced published geologic mapping.
Review of the Natural Resources Conservation Service (NRCS) Web Soils Survey shows that the
site is mapped as Alderwood gravelly sandy loam (AgC). The survey describes the soils being
formed from the weathering of glacial sediments which is also generally consistent with our
on-site exploration observations.
4.2 Site Stratigraphy
Subsurface conditions at the project site were inferred from the field explorations accomplished
for this study, visual reconnaissance of the site, and review of selected applicable geologic
literature. As shown on the exploration logs, soils encountered at the site consisted of fill of
variable thickness overlying native sediments interpreted as Vashon lodgement till. The following
sections presents more detailed subsurface information on the sediment types encountered at
the site.
Fill
Fill soils (those not naturally placed) were encountered in all of our recent and previous
explorations in the current project area with interpreted fill thicknesses ranging between 4 to
9 feet below the existing ground surface. Fill thicknesses at the two hand-augered boring
locations exceeded the depth drilled of 3 feet at each location. Figure 2 of this report includes
the observed fill thickness at each of the exploration locations at the time of drilling. The fill
generally consisted of loose to medium dense, moist, gray to brown, fine to medium sand with
variable silt content and variable gravel content. Looser fill with organic content was encountered
in exploration boring EB-6 (2003) at depths ranging between 0 and 5 feet below existing ground
surface. Deleterious materials such as plywood, plastic, and metal fragments were observed in
1 https://ngmdb.usgs.gov/ngmdb/ngmdb_home.html
2 https://www.dnr.wa.gov/geologyportal
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explorations EB-1 (2010), EB-1 (2004), EB-6 (2003) and HB-2 (2021). Existing fill is not
recommended for foundation support and may require remedial preparation below new paving.
Excavated existing fill material is suitable for reuse in structural fill applications if such reuse is
specifically allowed by project plans and specifications, if excessively organic and any other
deleterious materials are removed, and if moisture content is adjusted to allow compaction to
the specified level and to a firm and unyielding condition. Existing fill is not suitable for infiltration
of stormwater.
Vashon Lodgement Till
In all of our exploration borings with the exception of the hand-augered borings, we observed
dense to very dense, unsorted, silty fine sand with varying amounts of gravels interpreted to
represent lodgement till sediments. The observed depth to the top of lodgement till sediments
ranged between 4 and 9 feet (EB-2, 2004 and EB-1, 2004, respectively) below existing ground
surface elevation. In each boring that lodgement till was observed it extended beyond the depths
of the explorations, with the deepest observations at 35 feet (EB-1, 2010). The upper 4 to 6 feet
of the lodgement till in EB-1 (2010) and EB-6 (2003) was generally weathered and less dense,
oxidized, and siltier than the lower, unweathered portions of the unit seen in other explorations.
The till was deposited directly from basal, debris-laden glacial ice during the Vashon Stade of the
Fraser Glaciation approximately 12,500 to 15,000 years ago. The high relative density of the
unweathered till is due to its consolidation by the massive weight of the glacial ice from which it
was deposited. Consequently, these materials are dense to very dense, possess high-strength,
low-compressibility characteristics, and are relatively impermeable. The lodgement till is suitable
for foundation support with proper preparation. Excavated lodgement till is suitable for use in
structural fill applications if allowed by project specifications and provided that the moisture
content is adjusted to allow compaction to a firm and unyielding condition at the specified level.
The lodgement till has a large proportion of fine-grained material making it susceptible to
disturbance when wet. Lodgement till is not a suitable infiltration receptor.
4.3 Hydrology
Groundwater seepage was encountered in exploration borings EB-1 (July 2010) at 30 feet, EB-1
(March 2004) at 4 feet, EB-2 (March 2004) at 1 foot, and EB-3 (March 2004) at 5 to 7 feet. It is
our opinion that the groundwater in each of these borings except EB-1 (July 2010) was perched
near the interface between overlying existing fill and underlying lodgement till. Perched water
occurs when surface water infiltrates down through relatively permeable soils, such as existing
fill or weathered lodgement till and becomes trapped or “perched” atop a comparatively
low-permeability barrier, such as the unweathered lodgement till. When water becomes perched
within fill or above the unweathered till, it may travel laterally and may follow flow paths related
to permeable zones that may not correspond to ground surface topography. Groundwater
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deeper within the till such as at the location of EB-1 (July 2010) can accumulate in coarser-grained
pockets or lenses and is typically discontinuous.
The presence and quantity of groundwater will largely depend on the soil grain-size distribution,
topography, seasonal precipitation, site use, on- and off-site land usage, and other factors.
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II.GEOLOGIC HAZARDS AND MITIGATIONS
We reviewed mapped geologic hazards on the King County iMap, the previously referenced DNR
map, and the City of Renton GIS (https://maps.rentonwa.gov/). The reviewed maps do not
identify the presence of regulated critical slopes or erosion hazard areas on or immediately
adjacent to the project areas. However, the DNR map and King County iMap show that there is a
section near the southeastern edge of the project site that is mapped as a potential liquefaction
hazard, which is discussed further below. It appears unlikely, in our opinion, that the current
project will need to address requirements related to geotechnical critical areas.
5.0 LANDSLIDE HAZARDS AND MITIGATIONS
The topography of the current project areas is relatively flat to gently sloping. We reviewed
topographic contours presented on Figure 2 and did not identify any slopes greater than
40 percent within or near the project areas. Based on visual reconnaissance of the site existing
slopes appear to have performed well with no visual indications of unusual erosion, slope
instability, or emergent groundwater seepage. Given the subsurface conditions on the site and
the inclination and height of the slopes, it is our opinion that the risk of damage to the proposed
improvements by landslide activity on these slopes under both static and seismic conditions is
low. No detailed quantitative assessment of slope stability was completed as part of this study,
and none is warranted to support the project as currently proposed, in our opinion.
6.0 SEISMIC HAZARDS AND MITIGATIONS
All of Western Washington is at risk of strong seismic events resulting from movement of the
tectonic plates associated with the Cascadia Subduction Zone (CSZ), where the offshore Juan de
Fuca plate subducts beneath the continental North American plate. The site lies within a zone of
strong potential shaking from subduction zone earthquakes associated with the CSZ. The CSZ can
produce earthquakes up to magnitude 9.0, and the recurrence interval is estimated to be on the
order of 500 years. Geologists infer the most recent subduction zone earthquake occurred in
1700 (Goldfinger et al., 20121). Three main types of earthquakes are typically associated with
subduction zone environments: crustal, intraplate, and interplate earthquakes. Seismic records
in the Puget Sound region document a distinct zone of shallow crustal seismicity (e.g., the Seattle
Fault Zone). These shallow fault zones may include surficial expressions of previous seismic
1 Goldfinger, C., Nelson, C.H., Morey, A.E., Johnson, J.E., Patton, J.R., Karabanov, E., Gutierrez-Pastor, J., Eriksson, A.T., Gracia, E.,
Dunhill, G., Enkin, R.J, Dallimore, A., and Vallier, T., 2012, Turbidite Event History—Methods and Implications for Holocene
Paleoseismicity of the Cascadia Subduction Zone: U.S. Geological Survey Professional Paper 1661–F, 170 .
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events, such as fault scarps, displaced shorelines, and shallow bedrock exposures. The shallow
fault zones typically extend from the surface to depths ranging from 16 to 19 miles. A deeper
zone of seismicity is associated with the subducting Juan de Fuca plate. Subduction zone seismic
events produce intraplate earthquakes at depths ranging from 25 to 45 miles beneath the Puget
Lowland including the 1949, 7.2-magnitude event; the 1965, 6.5-magnitude event; and the 2001,
6.8-magnitude event and interplate earthquakes at shallow depths near the Washington coast
including the 1700 earthquake, which had a magnitude of approximately 9.0. The 1949
earthquake appears to have been the largest in this region during recorded history and was
centered in the Olympia area. Evaluation of earthquake return rates indicates that an earthquake
of the magnitude between 5.5 and 6.0 is likely within a given 20-year period.
Generally, there are four types of potential geologic hazards associated with large seismic events:
1) surficial ground rupture, 2) seismically induced landslides or lateral spreading, 3) liquefaction,
4)ground motion. The potential for each of these hazards to adversely impact the proposed
project is discussed below.
6.1 Surficial Ground Rupture
Generally, the largest earthquakes that have occurred in the Puget Sound area are sub-crustal
events with epicenters ranging from 50 to 70 kilometers in depth. Earthquakes that are
generated at such depths usually do not result in fault rupture at the ground surface. Surficial
ground rupture is possible during shallower crustal events in areas close to the Seattle Fault Zone,
which is located approximately 4.5 miles to the north and is the closest mapped fault zone to the
project. Due to the suspected long recurrence interval, and the distance of the site to known fault
traces, the potential for surficial ground rupture to occur at the project site is considered to be
low during the expected life of the proposed structures.
6.2 Liquefaction
Liquefaction is a process through which unconsolidated soil loses strength as a result of
vibrations, such as those which occur during a seismic event. During normal conditions, the
weight of the soil is supported by both grain-to-grain contacts and by the fluid pressure within
the pore spaces of the soil below the water table. Extreme vibratory shaking can disrupt the
grain-to-grain contact, increase the pore pressure, and result in a temporary decrease in soil
shear strength. The soil is said to be liquefied when nearly all of the weight of the soil is supported
by pore pressure alone. Liquefaction can result in deformation of the sediment and settlement
of overlying structures. Areas most susceptible to liquefaction include those areas underlain by
very soft to stiff, non-cohesive silt and very loose to medium dense, non-silty to silty sands with
low relative densities, accompanied by a shallow water table.
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There is a portion of the southeastern edge of the site that is mapped as a liquefaction hazard.
The mapped hazard is outside of the proposed improvement areas. The proposed project is not
expected to have high risk of damage due to liquefaction because substantial deposits of
saturated loose granular sediments were not observed. A detailed liquefaction hazard analysis
was not performed as part of this study, and none is warranted based on existing subsurface
data, in our opinion.
6.3 Ground Motion/Seismic Site Class (2018 International Building Code)
Structural design of the new building additions should follow 2018 International Building Code
(IBC) standards. We recommend that the project be designed in accordance with Site Class “C”
in accordance with the 2018 IBC, and the publication American Society of Civil Engineers (ASCE) 7
referenced therein, the most recent version of which is ASCE 7-16.
7.0 EROSION CONTROL
Project plans should include implementation of temporary erosion controls in accordance with
local standards of practice. Control methods should include limiting earthwork to seasonally drier
periods, if possible, use of perimeter silt fences, stabilized construction entrances, and straw
mulch in exposed areas. Removal of existing vegetation should be limited to those areas that are
required to construct the project, and new landscaping and vegetation with equivalent erosion
mitigation potential should be established as soon as practical after grading is complete. During
construction, surface water should be collected as close as possible to the source to minimize silt
entrainment that could require treatment or detention prior to discharge. Timely
implementation of permanent drainage control measures should also be a part of the project
plans, and will help reduce erosion and generation of silty surface water onsite.
The Ecology Construction Storm Water General Permit requires weekly Temporary Erosion and
Sedimentation Control (TESC) inspections, turbidity monitoring and pH monitoring for all sites
1 or more acre in size that discharge stormwater to surface waters of the state. Because we
anticipate that the proposed project will not require disturbance of more than 1 acre, we
anticipate that these inspection and reporting requirements will not be triggered. The following
recommendations are related to general erosion potential and mitigation.
Best management practices (BMPs) should include but not be limited to:
1.Construction activity should be scheduled or phased as much as possible to reduce the
amount of earthwork activity that is performed during the winter months.
2.The winter performance of a site is dependent on a well-conceived plan for control of site
erosion and stormwater runoff. The site plan should include ground-cover measures,
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access roads, and staging areas. The contractor should be prepared to implement and
maintain the required measures to reduce the amount of exposed ground.
3.TESC measures for a given area to be graded or otherwise worked should be installed
soon after ground clearing. The recommended sequence of construction within a given
area after clearing would be to install TESC elements and perimeter flow control prior to
starting grading.
4.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 unworked. During the winter months, areas that are to
be left unworked 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 stormwater
conveyance channels through work areas to route runoff to the approved
treatment/discharge facilities.
5.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 a cost-effective cover measure and can be
made wind-resistant with the application of a tackifier after it is placed.
6.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.
7.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 silt
fences around pile perimeters.
It is our opinion that with the proper implementation of the TESC plans and by field-adjusting
appropriate mitigation elements (BMPs) during construction, the potential adverse impacts from
erosion hazards on the project may be mitigated.
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III. PRELIMINARY DESIGN RECOMMENDATIONS
8.0 INTRODUCTION
Our explorations indicate that, from a geotechnical engineering standpoint, the proposed
building additions are feasible provided the recommendations contained herein are properly
followed. The project area is underlain by a layer of existing fill that is variable in thickness and
density. Existing fill or loose soils are not suitable for support of new foundations, and warrant
remedial preparation where occurring below paving.
South Addition - the southmost addition area, near hand-auger exploration HB-2, might benefit
from the use of pin piles or aggregate pier ground improvement due to the depth of existing fill
and constraints imposed by adjacent existing structures. Pin piles are feasible and are discussed
in general terms later in this report. We should be allowed to offer situation-specific geotechnical
engineering recommendations if pin piles are selected for foundation support. Removal and
replacement of existing fill is also a feasible way to support the planned south addition if the
overexcavation program can be completed without encroaching on support soils for existing
adjacent structures. Support soils for existing structures should be considered to be defined by a
line projected down and away from all foundation elements at an angle of 1H:1V (Horizontal:
Vertical).
North Additions and Courtyard Infill - The north addition areas and courtyard infill appear likely
to have suitable bearing soils at a depth similar to existing adjacent structures, and therefore
removal and replacement of existing fill soils below the planned building additions is thought to
be feasible. This report provides geotechnical engineering recommendations focused on the
remove/replace approach for dealing with existing fill below planned new buildings. We are
available on request to discuss other possible foundation support approaches. It is worth noting
that the hand-auger boring in the courtyard infill area did not penetrate deep enough to confirm
the depth to native soils. At the time this report is written the nature of the courtyard infill project
is not known. If the courtyard infill will be a building addition or other substantial structure, we
recommend completion of a deeper exploration in the courtyard that was beyond the scope of
the current study.
This report is preliminary because a project concept has not yet been prepared at the time this
report is written. AESI should be allowed to review the final project plans once they have been
developed to update our recommendations, as necessary.
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9.0 SITE PREPARATION
Erosion and surface water control should be established around the perimeter of the excavation
to satisfy City of Renton requirements.
Building Pad Areas - Site preparation should include removal of all existing pavement, structures,
buried utilities, and any other deleterious material from below the new building additions.
Existing fill should be removed to expose suitable native materials suitable for structural support.
Structural fill may then be placed as needed to reach building pad grade. At the time this report
is written a site development plan has not been selected. We should be allowed to review the
site development plan when one is selected and discuss possible site preparation and structural
support plans that are appropriate to the project plan.
Paving Areas - Areas of planned paving should be prepared by stripping existing vegetation and
topsoil, removing structures and utilities to be demolished, and excavating to planned paving
subgrade elevation. The resulting subgrade should then be evaluated visually, compacted, and
proof-rolled. Exposed soils are expected to consist of existing fill and lodgement till depending
on the location and finished subgrade elevation. Areas with organic or deleterious material, or
areas that yield during proof-rolling should receive additional preparation tailored to proof-
rolling results and field conditions at the time of construction.
9.1 Site Drainage and Surface Water Control
The site should be graded to prevent water from ponding in construction areas and/or flowing
into excavations. Exposed grades should be crowned, sloped, and smooth drum-rolled at the end
of each day to facilitate drainage. Accumulated water must be removed from subgrades and work
areas immediately prior to performing further work in the area. Equipment access may be
limited, and the amount of soil rendered unfit for use as structural fill may be greatly increased
if drainage efforts are not accomplished in a timely sequence. If an effective drainage system is
not utilized, project delays and increased costs could be incurred due to the greater quantities of
wet and unsuitable fill, or poor access and unstable conditions.
We do not anticipate the need for extensive dewatering in advance of excavations. However, the
contractor should be prepared to intercept any groundwater seepage entering the excavations
and route it to a suitable discharge location.
Final exterior grades should promote free and positive drainage away from buildings at all times.
Water must not be allowed to pond or to collect adjacent to foundations or within immediate
building areas. We recommend that a gradient of at least 3 percent for a minimum distance of
10 feet from the building perimeters be provided, except in paved locations. In paved locations,
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a minimum gradient of 1 percent should be provided, unless provisions are included for collection
and disposal of surface water adjacent to the structure.
9.2 Subgrade Protection
If building construction will proceed during the winter, we recommend the use of a working
surface of sand and gravel, crushed rock, or quarry spalls to protect exposed soils, particularly in
areas supporting concentrated equipment traffic. In winter construction staging areas and areas
that will be subjected to repeated heavy loads, such as those that occur during construction of
masonry walls, a minimum thickness of 12 inches of quarry spalls or 18 inches of pit run sand and
gravel is recommended. If subgrade conditions are soft and silty, a geotextile separation fabric,
such as Mirafi 500X or approved equivalent, should be used between the subgrade and the new
fill. For building pads where floor slabs and foundation construction will be completed in the
winter, a similar working surface should be used, composed of at least 6 inches of pit run sand
and gravel or crushed rock. Construction of working surfaces from advancing fill pads could be
used to avoid directly exposing the subgrade soils to vehicular traffic.
Foundation subgrades may require protection from foot and equipment traffic and ponding of
runoff during wet weather conditions. Typically, compacted crushed rock or a lean-mix concrete
mat placed over a properly prepared subgrade provides adequate subgrade protection.
Foundation concrete should be placed and excavations backfilled as soon as possible to protect
the bearing surface.
9.3 Proof-Rolling and Subgrade Compaction
Following the recommended clearing, site stripping, planned excavation, and any overexcavation
required to remove existing fill, the stripped subgrade within the building areas should be
proof-rolled with heavy, rubber-tired construction equipment, such as a fully-loaded tandem-
axle dump truck. Proof-rolling should be performed prior to structural fill placement or
foundation excavation. The proof-roll should be monitored by the geotechnical engineer so that
any soft or yielding subgrade soils can be identified. Any soft/loose, yielding soils should be
removed to a stable subgrade. The subgrade should then be scarified, adjusted in moisture
content, and recompacted to the required density. Proof-rolling should only be attempted if soil
moisture contents are at or near optimum moisture content. Proof-rolling of wet subgrades could
result in further degradation. Low areas and excavations may then be raised to the planned
finished grade with compacted structural fill. Subgrade preparation and selection, placement,
and compaction of structural fill should be performed under engineering-controlled conditions
in accordance with the project specifications.
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9.4 Overexcavation/Stabilization
Construction during extended wet weather periods could create the need to overexcavate
exposed soils if they become disturbed and cannot be recompacted due to elevated moisture
content and/or weather conditions. Even during dry weather periods, soft/wet soils, which may
need to be overexcavated, may be encountered in some portions of the site. If overexcavation is
necessary, it should be confirmed through continuous observation and testing by AESI. Soils that
have become unstable may require remedial measures in the form of one or more of the
following:
1. Drying and recompaction. Selective drying may be accomplished by scarifying or
windrowing surficial material during extended periods of dry and warm weather.
2. Removal of affected soils to expose a suitable bearing subgrade and replacement with
compacted structural fill.
3. Mechanical stabilization with a coarse crushed aggregate compacted into the subgrade,
possibly in conjunction with a geotextile.
4. Soil/cement admixture stabilization.
9.5 Wet Weather Conditions
If construction proceeds during an extended wet weather construction period and the
moisture-sensitive site soils become wet, they will become unstable. Therefore, the bids for site
grading operations should be based upon the time of year that construction will proceed. It is
expected that in wet conditions additional soils may need to be removed and/or other stabilization
methods used, such as a coarse crushed rock working mat to develop a stable condition if silty
subgrade soils are disturbed in the presence of excess moisture. The severity of construction
disturbance will be dependent, in part, on the precautions that are taken by the contractor to
protect the moisture- and disturbance-sensitive site soils. If overexcavation is necessary, it should
be confirmed through continuous observation and testing by a representative of our firm.
9.6 Temporary and Permanent Cut Slopes
In our opinion, stable construction slopes should be the responsibility of the contractor and
should be determined during construction. For estimating purposes, however, we anticipate that
temporary, unsupported cut slopes in the existing fill can be made at a maximum slope of 1.5H:1V
or flatter. Temporary slopes in dense to very dense till sediments may be planned at 1H:1V. As is
typical with earthwork operations, some sloughing and raveling may occur, and cut slopes may
have to be adjusted in the field. If groundwater seepage is encountered in cut slopes, or if surface
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water is not routed away from temporary cut slope faces, flatter slopes will be required. In
addition, WISHA/OSHA regulations should be followed at all times. Permanent cut and structural
fill slopes that are not intended to be exposed to surface water should be designed at inclinations
of 2H:1V or flatter. All permanent cut or fill slopes should be compacted to at least 95 percent of
the modified Proctor maximum dry density, as determined by ASTM D-1557, and the slopes
should be protected from erosion by sheet plastic until vegetation cover can be established
during favorable weather.
9.7 Frozen Subgrades
If earthwork takes place during freezing conditions, all exposed subgrades should be allowed to
thaw and then be recompacted prior to placing subsequent lifts of structural fill or foundation
components. Alternatively, the frozen material could be stripped from the subgrade to reveal
unfrozen soil prior to placing subsequent lifts of fill or foundation components. The frozen soil
should not be reused as structural fill until allowed to thaw and adjusted to the proper moisture
content, which may not be possible during winter months.
10.0 STRUCTURAL FILL
Structural fill should be placed and compacted according to the recommendations presented in
this section and requirements included in project specifications. All references to structural fill in
this report refer to subgrade preparation, fill type, placement, and compaction of materials, as
discussed in this section. If a percentage of compaction is specified under another section of this
report, the value given in that section should be used.
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 at least 95 percent of the modified
Proctor maximum dry density using ASTM D-1557 as the standard. In the case of roadway and
utility trench filling, the backfill should be placed and compacted in accordance with City of
Renton standards. For planning purposes, we recommend the use of a well-graded sand and
gravel for road and utility trench backfill. At this time we are not aware of any planned
right-of-way work associated with the project.
The contractor should note that AESI should evaluate any proposed fill soils prior to their use in
fills. This would require that we have a sample of the material at least 3 business days 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 is not recommended during
the winter months or under wet site and weather conditions. Most of the on-site soils are
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moisture-sensitive and have natural moisture contents over optimum for compaction and will
likely require moisture-conditioning before use as structural fill. In addition, construction
equipment traversing the site when the soils are wet can cause considerable disturbance.
If import soil is required, 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 and at least 30 percent retained on the No. 4 sieve.
A representative from our firm should observe the subgrades and be present during placement
of structural fill to observe the work and perform a representative number of in-place density
tests. In this way, the adequacy of the earthwork may be evaluated as filling progresses and any
problem areas may be corrected at that time. It is important to understand that taking random
compaction tests on a part-time basis will not assure uniformity or acceptable performance of a
fill. As such, we are available to aid the owner in developing a suitable monitoring and testing
frequency.
11.0 FOUNDATIONS
Preliminary recommendations are presented for conventional shallow foundations supported
directly by dense native soils, or by new structural fill overlying suitable native soils. Preliminary
pin pile recommendations are provided for areas where existing fill soils cannot be removed and
replaced due to the presence of existing adjacent structures.
11.1 Shallow Foundations
We expect the depth from existing grade to bearing soil in building addition areas will vary,
however we anticipate that existing fill does not extend deeper than foundation level for existing
buildings adjacent to the additions. The existing on-site fill was thickest (about 9 feet in depth) in
the southwestern portion of the site, in the vicinity of EB-1 (2004). Where present, existing fill
should be removed below the building pad, exposing medium dense to very dense native
sediments.
Spread footings may be used for building support when founded directly on undisturbed native
sediments, on structural fill placed over suitable native sediments. If foundations will be
supported by a combination of very dense native sediments and new structural fill, we
recommend that an allowable bearing pressure of 3,000 pounds per square foot (psf) be used for
design purposes, including both dead and live loads. Higher foundation soil bearing pressures
may be suitable if new footings will be supported entirely on dense to very dense native soils.
An increase of one-third may be used for short-term wind or seismic loading.
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Perimeter footings should be buried at least 18 inches into the surrounding soil for frost
protection. However, all footings must penetrate to the prescribed bearing stratum, and no
footing should be founded in or above organic or loose soils.
It should be noted that the area bound by lines extending downward at 1H:1V from any footing
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:1V line extending down from any footing
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 footings founded as described above should be on the order of ¾ inch
or less. However, disturbed soil not removed from footing excavations prior to footing placement
and footings placed above loose soils 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. Such inspections may be required by the governing municipality. Perimeter footing
drains should be provided, as discussed under the “Drainage Considerations” Section 14.0 of this
report.
11.2 Pin Piles
Pin piles should be installed by a local contractor with demonstrated expertise in pin pile
installations. We recommend preliminary planning assuming pin pile axial compressive capacity
of 12,000 pounds on a 3-inch-diameter pile. Piles with smaller and larger capacities are possible,
if needed. We should be allowed to offer situation-specific pin pile recommendations if project
plans are prepared that include the use of pin piles.
In general, pin piles are installed with an air or hydraulic impact hammer until the specified
refusal criteria are met. If multiple pipe sections are required, the pipes should be joined with an
extension pin inside the pipe, and/or a sleeve on the outside. If uplift loads are expected to be
placed on the piles at any time, the connections should also be securely welded to prevent pipe
separation at joints.
Although vertical pin piles can provide small uplift and lateral capacities, we recommend that
these contributions be neglected in designing the new foundation system. The structural
engineer should provide pile spacing, locations, splicing details, foundation connection details,
and any other structural design recommendations that are needed.
Pin piles are driven until specific refusal criteria are achieved. Pile lengths are difficult to estimate
in advance. At this site in addition to achieving the required driving resistance, piles are required
to reach a minimum depth. We recommend that piles fully penetrate existing fill soils to bear on
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lodgement till, and that all piles achieve a minimum penetration depth of 5 feet below the level
of any adjacent temporary or permanent excavations. It should be noted that the subsurface
conditions that will be encountered during pile driving could include construction waste and
compacted fill soils.
We recommend that we be allowed to observe the installation of pin piles. We would observe
materials, equipment, and procedures, and confirm refusal for each pile. The purpose of our
observations is to confirm that the conditions observed in our explorations and assumed in
preparation of our recommendations are consistent with those encountered at the time of
construction, and to confirm that the materials, procedures, and refusal criteria are consistent
with those we assumed while formulating our recommendations contained in this report. We
recommend that we be allowed to agree on mutually acceptable driving resistance criteria with
the pile contractor selected for the project, and that the agreed-on driving criteria be verified by
at least one load test for each pile type.
12.0 FLOOR SUPPORT
If crawl-space floors are used, an impervious moisture barrier should be provided above the soil
surface within the crawl space. Slab-on-grade floors may be used over medium dense to very
dense native soils, or over structural fill placed as recommended in the “Site Preparation” and
“Structural Fill” sections of this report. Slab-on-grade floors should be cast atop a minimum of
4 inches of washed pea gravel or washed crushed “chip” rock with less than 3 percent passing
the U.S. No. 200 sieve to act as a capillary break. The floors should also be protected from
dampness by covering the capillary break layer with an impervious moisture barrier at least
10 mils in thickness.
If any of the building addition areas will use pin pile support for foundations, floors could be
supported on pin piles. Alternatively, floor slabs could be supported by a new layer of compacted
structural fill at least 2 feet thick, underlain by existing fill soils. If this alternative is selected, the
existing fill soil should be prepared in accordance with the “Site Preparation” section of this
report, and new fill should be placed as recommended in the “Structural Fill” section. If existing
fill is left in place below new floors and pin piles are not used for floor support, there is some
potential for larger than normal post-construction settlement. The settlement risk is offset by
substantial cost savings at the time of construction. We are available on request to discuss floor
support over existing fill.
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13.0 FOUNDATION WALLS
All backfill behind foundation walls or around foundation units should be placed as per our
recommendations for structural fill and as described in this section of the report. Horizontally
backfilled walls, which are free to yield laterally at least 0.1 percent of their height, may be
designed to resist active earth pressure represented by an equivalent fluid equal to 35 pounds
per cubic foot (pcf). Fully restrained, horizontally backfilled, rigid walls that cannot yield should
be designed for an equivalent fluid of 50 pcf. Walls with sloping backfill up to a maximum gradient
of 2H:1V should be designed using an equivalent fluid of 55 pcf for yielding conditions or 75 pcf
for fully restrained conditions. If parking areas are adjacent to walls, a surcharge equivalent to
2 feet of soil should be added to the wall height in determining lateral design forces.
As required by the 2018 IBC, retaining wall design should include a seismic surcharge pressure in
addition to the equivalent fluid pressures presented above. Considering the site soils and the
recommended wall backfill materials, we recommend a seismic surcharge pressure of
5H and 10H psf, where H is the wall height in feet for the “active” and “at-rest” loading
conditions, respectively. The seismic surcharge should be modeled as a rectangular distribution
with the resultant applied at the midpoint of the walls.
The lateral pressures presented above are based on the conditions of a uniform backfill consisting
of excavated on-site soils, or imported structural fill compacted to 90 percent of ASTM D-1557.
A higher degree of compaction is not recommended, as this will increase the pressure acting on
the walls. A lower compaction may result in settlement of the slab-on-grade or other structures
supported above the walls. Thus, the compaction level is critical and must be tested by our firm
during placement. Surcharges from adjacent footings or heavy construction equipment must be
added to the above values. Perimeter footing drains should be provided for all retaining walls, as
discussed under the “Drainage Considerations” section of this report.
It is imperative that proper drainage be provided so that hydrostatic pressures do not develop
against the walls. This would involve installation of a minimum, 1-foot-wide blanket drain to
within 1 foot of finish grade for the full wall height using imported, washed gravel against the
walls. A prefabricated drainage mat is not a suitable substitute for the gravel blanket drain unless
all backfill against the wall is free-draining.
13.1 Passive Resistance and Friction Factors
Lateral loads can be resisted by friction between the foundation and the natural glacial soils or
supporting structural fill soils, and by passive earth pressure acting on the buried portions of the
foundations. The foundations must be backfilled with structural fill and compacted to at least
95 percent of the maximum dry density to achieve the passive resistance provided below. We
recommend the following allowable design parameters:
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•Passive equivalent fluid = 250 pcf
•Coefficient of friction = 0.35
14.0 DRAINAGE CONSIDERATIONS
All retaining and perimeter foundation walls should be provided with a drain at the base of the
footing elevation. Drains should consist of rigid, perforated, PVC pipe surrounded by washed
drain rock. The level of the perforations in the pipe should be set at or slightly below the bottom
of the footing grade beam, and the drains should be constructed with sufficient gradient to allow
gravity discharge away from the building. In addition, all retaining walls should be lined with a
minimum, 12-inch-thick, washed gravel blanket that extends to within 1 foot of the surface and
is continuous with the foundation drain. Roof and surface runoff should not discharge into the
foundation drain system, but should be handled by a separate, rigid, tightline drain. In planning,
exterior grades adjacent to walls should be sloped downward away from the structure to achieve
surface drainage.
15.0 PAVEMENT AND SIDEWALK RECOMMENDATIONS
The pavement sections included in this report section are for driveway and parking areas onsite,
and are not applicable to right-of-way improvements. At this time, we are not aware of any
planned right-of-way improvements; however, if any new paving of public streets is required, we
should be allowed to offer situation-specific recommendations.
Pavement and sidewalk areas should be prepared in accordance with the “Site Preparation”
section of this report. Soft or yielding areas should be overexcavated to provide a suitable
subgrade and backfilled with structural fill.
New paving may include areas subject only to light traffic loads from passenger vehicles driving
and parking, and may also include areas subject to heavier loading from vehicles that may include
buses, fire trucks, food service trucks, and garbage trucks. In light traffic areas, we recommend a
pavement section consisting of 3 inches of hot-mix asphalt (HMA) underlain by 4 inches of
crushed surfacing base course. In heavy traffic areas, we recommend a minimum pavement
section consisting of 4 inches of HMA underlain by 2 inches of crushed surfacing top course and
4 inches of crushed surfacing base course. The crushed rock courses must be compacted to
95 percent of the maximum density, as determined by ASTM D-1557. All paving materials should
meet gradation criteria contained in the current Washington State Department of Transportation
(WSDOT) Standard Specifications.
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Depending on construction staging and desired performance, the crushed base course material
may be substituted with asphalt treated base (ATB) beneath the final asphalt surfacing, if desired.
The substitution of ATB should be as follows: 4 inches of crushed rock can be substituted
with 3 inches of ATB, and 6 inches of crushed rock may be substituted with 4 inches of ATB.
ATB should be placed over a native or structural fill subgrade compacted to a minimum
of 95 percent relative density, and a 1½- to 2-inch thickness of crushed rock to act as a working
surface. If ATB is used for construction access and staging areas, some rutting and disturbance of
the ATB surface should be expected to result from construction traffic. The contractor should
remove any ATB areas damaged by construction equipment and replace them with properly
compacted ATB prior to final surfacing.
16.0 INFILTRATION FEASIBILITY
The on-site soils consist of fill and dense silty glacial till. The existing fill is not permitted to serve
as an infiltration receptor, and lodgement till is not a suitable infiltration receptor due to low
permeability. Stormwater infiltration is not recommended.
17.0 PROJECT DESIGN AND CONSTRUCTION MONITORING
We recommend that AESI perform a geotechnical review of the plans prior to final design
completion. In this way, we can confirm that our recommendations have been correctly
interpreted and implemented in the design. The City of Renton may require a plan review by the
geotechnical engineer as a condition of permitting.
We recommend that AESI be retained to provide geotechnical special inspections during
construction, and preparation of a final summary letter when construction is complete. The City
of Renton may require such geotechnical special inspections. The integrity of the earthwork and
foundations 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.
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We have enjoyed working with you on this study and are confident 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
______________________________
Aaron R. Turnley, G.I.T.
Senior Staff Geologist
______________________________
Bruce W. Guenzler, L.E.G. Matthew A. Miller. P.E.
Senior Associate Geologist Principal Engineer
Attachments: Figure 1. Vicinity Map
Figure 2. Existing Site and Exploration Plan
Appendix A. Exploration Logs
KING COUNTY
KING COUNTY
RENTON
PROJ NO.
NOTE: BLACK AND WHITE
REPRODUCTION OF THIS COLOR
ORIGINAL MAY REDUCE ITS
EFFECTIVENESS AND LEAD TO
INCORRECT INTERPRETATION DATE:FIGURE:
±\\kirkfile2\GIS\GIS_Projects\aY00post0716\000669 Lindbergh HS\aprx\20000669E005 F1 VM_Lindbergh.aprx | 20000669E005 F1 VM_Lindbergh | 9/13/2021 2:53 PMDATA SOURCES / REFERENCES:
USGS: 7.5' SERIES TOPOGRAPHIC MAPS, ESRI/I-CUBED/NGS 2013
KING CO: STREETS, CITY LIMITS, PARCELS, PARKS 3/20
LOCATIONS AND DISTANCES SHOWN ARE APPROXIMATE
0 2000
Feet
VICINITY MAP
LINDBERGH HS IMPROVEMENTS
RENTON, WASHINGTON
20000669E005 9/21 1
King County
¥
¥
¥
¬«
¬«169
!(
SITE
King County
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(4204104304
0
0 410400430
42
0
39042
0400 King CountyRentonHB-1
HB-2
EB-6, 5.5FT
EB-1, 8FT
EB-1, 4FT
EB-2, 7FT
EB-3, 6FT
EB-1, 9FT
EB-2, 4FT
EB-3, 5FT
EagleView Technologies, Inc.
±
BLACK AND WHITE REPRODUCTION OF THIS COLOR ORIGINAL MAY REDUCE ITS
EFFECTIVENESS AND LEAD TO INCORRECT INTERPRETATION
\\kirkfile2\gis\GIS_Projects\aY00post0716\000669 Lindbergh HS\aprx\20000669E005 F2 ES_Lindbergh.aprx | 20000669E005 F2 ES_Lindbergh | 9/27/2021 9:23 AMPROJ NO.DATE:FIGURE:
0 80
FEET
NOTE: HISTORICAL EXPLORATIONS OUTSIDE THE CURRENT
WORK AREA ARE NOT SHOWN ON THE FIGURE AND NOT
INCLUDED IN THE APPENDIX
DATA SOURCES / REFERENCES:
PSLC: KING COUNTY 2016, GRID CELL SIZE IS 3'.
DELIVERY 1 FLOWN 2/24/16 - 3/28/16
CONTOURS FROM LIDAR
KING CO: STREETS, PARCELS, 3/20
AERIAL PICTOMETRY INT. 2019
LOCATIONS AND DISTANCES SHOWN ARE APPROXIMATE
20000669E005 9/21 2
EXISTING SITE AND
EXPLORATION PLAN
LINDBERGH HS ADDITIONS
RENTON, WASHINGTON
LEGEND
SITE
!(EXPLORATION BORING, DEPTH OF FILL
(2021)
!(HAND BORING (2021)
!(EXPLORATION BORING, DEPTH OF FILL
(2010)
!(EXPLORATION BORING, DEPTH OF FILL
(2004)
!(EXPLORATION BORING, DEPTH OF FILL
(2003)
CITY BOUNDARY
PARCEL
CONTOUR 10 FT
CONTOUR 2 FT
APPENDIX A
Exploration Logs
Topsoil - 4 to 6 inches
Fill
Moist, grayish brown, silty, fine SAND, some medium to coarse sand, trace
gravel; unsorted (SM).
Vashon Lodgement Till
Moist, grayish brown, silty, fine SAND, some medium to coarse sand,
some gravel; unsorted (SM).
As above.
Driller reports hard drilling.
Moist, grayish brown, silty, fine SAND, some medium to coarse sand,
some broken gravel; diamict (SM).
Moist, grayish brown, silty, fine SAND, some medium to coarse sand, trace
gravel; diamict (SM).
Driller reports hard drilling.
Moist to very moist, grayish brown, silty, fine SAND, some medium to
coarse sand; contains broken gravel; occasional sand lens; diamict (SM).
S-1
S-2
S-3
S-4
S-5
S-6
20
26
27
12
20
27
20
35
50/5"
26
50/3"
50/6"
35
43
50/5"
Bottom of exploration boring at 21.4 feet
No groundwater encountered.
Ground Surface Elevation (ft)
Grab SampleSymbol 3.25 inch ID, +/- 8 inch OD
40
Datum
Hammer Weight/Drop
Sampler Type (ST):
~425
5
10
15
20
EB-1
Ring Sample
No RecoveryGraphic 10 Other TestsHole Diameter (in)
DESCRIPTION
Driller/Equipment
Blows/6"JHS
ART2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)Water LevelProject Name
Water Level ()Approved by:
30
Blows/Foot
SamplesDepth (ft)S
T
Exploration Number
20000669E005
9/11/21,9/11/21
Logged by:
Shelby Tube Sample
140# / 30
Advanced Drill Technologies / D-50 Track Mount
Exploration Boring
Water Level at time of drilling (ATD)
Lindbergh High School Additions
M - Moisture
Project Number
20
Renton, WA
Date Start/Finish
CompletionLocation
Sheet
1 of 1
NAVD 88
WellAESIBOR 20000669E005.GPJ September 27, 202153
4747
5050/5"
5050/3"
5050/6"
5050/5"
Topsoil - 4 to 6 inches
Fill
Moist, brownish gray with faint iron oxide staining, silty, fine SAND, some
medium to coarse sand, some gravel; unsorted (SM)
Moist, grayish brown, silty, fine SAND, some medium to coarse sand, trace
gravel; unsorted (SM).
Drilling action changes at 7 feet.
Vashon Lodgement Till
Moist, grayish brown, silty, fine SAND, some medium to coarse sand, trace
gravel; diamict (SM).
Moist, grayish brown, silty, fine SAND, trace medium to coarse sand;
diamict (SM).
Moist, grayish brown, silty, fine SAND, some medium to coarse sand, trace
gravel; diamict (SM).
No recovery due to gravel.
S-1
S-2
S-3
S-4
S-5
S-6
6
4
3
3
3
8
30
50/6"
20
50/6"
50/6"
50/2"
Bottom of exploration boring at 20.2 feet
No groundwater encountered.
Ground Surface Elevation (ft)
Grab SampleSymbol 3.25 inch ID, +/- 8 inch OD
40
Datum
Hammer Weight/Drop
Sampler Type (ST):
~427.5
5
10
15
20
EB-2
Ring Sample
No RecoveryGraphic 10 Other TestsHole Diameter (in)
DESCRIPTION
Driller/Equipment
Blows/6"JHS
ART2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)Water LevelProject Name
Water Level ()Approved by:
30
Blows/Foot
SamplesDepth (ft)S
T
Exploration Number
20000669E005
9/11/21,9/11/21
Logged by:
Shelby Tube Sample
140# / 30
Advanced Drill Technologies / D-50 Track Mount
Exploration Boring
Water Level at time of drilling (ATD)
Lindbergh High School Additions
M - Moisture
Project Number
20
Renton, WA
Date Start/Finish
CompletionLocation
Sheet
1 of 1
NAVD 88
WellAESIBOR 20000669E005.GPJ September 27, 202177
1111
5050/6"
5050/6"
5050/6"
5050/2"
Topsoil - 4 to 6 inches
Fill
Moist, brownish gray with oxidation, silty, fine SAND, some medium to
coarse sand; unsorted (SM).
Moist, grayish brown, silty, fine SAND, some medium to coarse sand, trace
gravel; fill lifts; unsorted (SM).
Vashon Lodgement Till
Drill change at 6 feet.
Moist, grayish brown, silty, fine SAND, some medium to coarse sand, trace
broken gravel; diamict (SM).
As above.
As above; faint iron oxide staining.
As above.
S-1
S-2
S-3
S-4
S-5
S-6
3
2
5
15
20
28
14
50/6"
19
50/6"
50/4"
50/5"
Bottom of exploration boring at 20.4 feet
No groundwater encountered.
Ground Surface Elevation (ft)
Grab SampleSymbol 3.25 inch ID, +/- 8 inch OD
40
Datum
Hammer Weight/Drop
Sampler Type (ST):
~422.5
5
10
15
20
EB-3
Ring Sample
No RecoveryGraphic 10 Other TestsHole Diameter (in)
DESCRIPTION
Driller/Equipment
Blows/6"JHS
ART2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)Water LevelProject Name
Water Level ()Approved by:
30
Blows/Foot
SamplesDepth (ft)S
T
Exploration Number
20000669E005
9/11/21,9/11/21
Logged by:
Shelby Tube Sample
140# / 30
Advanced Drill Technologies / D-50 Track Mount
Exploration Boring
Water Level at time of drilling (ATD)
Lindbergh High School Additions
M - Moisture
Project Number
20
Renton, WA
Date Start/Finish
CompletionLocation
Sheet
1 of 1
NAVD 88
WellAESIBOR 20000669E005.GPJ September 27, 202177
4848
5050/6"
5050/6"
5050/4"
5050/5"
Landscaping Mulch - 2 to 3 inches
Fill
Loose, moist, light brown, silty, fine SAND, some gravel, some medium to
coarse sand; unsorted (SM).
As above.
S-1
S-2
Bottom of exploration boring at 3 feet
No groundwater encountered.
Ground Surface Elevation (ft)
Grab SampleSymbol 3.25 inch ID, +/- 8 inch OD
40
Datum
Hammer Weight/Drop
Sampler Type (ST):
~425
5
HB-1
Ring Sample
No RecoveryGraphic 10 Other TestsHole Diameter (in)
DESCRIPTION
Driller/Equipment
Blows/6"JHS
ART2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)Water LevelProject Name
Water Level ()Approved by:
30
Blows/Foot
SamplesDepth (ft)S
T
Exploration Number
20000669E005
9/11/21,9/11/21
Logged by:
Shelby Tube Sample
140# / 30
Hand Auger
Exploration Boring
Water Level at time of drilling (ATD)
Lindbergh High School Additions
M - Moisture
Project Number
20
Renton, WA
Date Start/Finish
CompletionLocation
Sheet
1 of 1
NAVD 88
WellAESIBOR 20000669E005.GPJ September 27, 2021
Landscaping Mulch - 4 to 6 inches
Fill
Loose, moist, light brown, fine SAND, some silt, some gravel, some
medium to coarse sand; unsorted (SP-SM).
Loose, moist, light brown, fine SAND, some silt, some gravel, some
medium to coarse sand; metal debris; unsorted (SP-SM).
S-1
S-2
Bottom of exploration boring at 2.5 feet
No groundwater encountered.
Ground Surface Elevation (ft)
Grab SampleSymbol 3.25 inch ID, +/- 8 inch OD
40
Datum
Hammer Weight/Drop
Sampler Type (ST):
~397.5
5
HB-2
Ring Sample
No RecoveryGraphic 10 Other TestsHole Diameter (in)
DESCRIPTION
Driller/Equipment
Blows/6"JHS
ART2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)Water LevelProject Name
Water Level ()Approved by:
30
Blows/Foot
SamplesDepth (ft)S
T
Exploration Number
20000669E005
9/11/21,9/11/21
Logged by:
Shelby Tube Sample
140# / 30
Hand Auger
Exploration Boring
Water Level at time of drilling (ATD)
Lindbergh High School Additions
M - Moisture
Project Number
20
Renton, WA
Date Start/Finish
CompletionLocation
Sheet
1 of 1
NAVD 88
WellAESIBOR 20000669E005.GPJ September 27, 2021
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bwgO@M@RPPPPVVYePPUMPPU p @T@
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Asphalt - 2 inches
Vashon Lodgement Till
Very dense, moist, light gray-brown, silty, fine SAND, trace gravel;
unsorted; some oxidation (SM).
Very dense, moist, light gray-brown, silty, fine SAND, trace gravel;
unsorted; no oxidation (SM).
As above.
6
21
41
33
50/4"
38
50/3"
S-1
S-2
S-3
Bottom of exploration boring at 6 feet
Moderate seepage below asphalt layer. No visible seepage in native soils.
1 of 1
N/A
Sheet
Depth(ft)Exploration Number
170046E001
M - Moisture
6 inches
40
Datum
S
T Graphic10 OtherTestsHole Diameter (in)
DESCRIPTION
Location
Water Level ()Approved by:
30
Blows/Foot
Driller/Equipment
Blows/6"Boretec / Mini-Track
Well5
10
15 WaterLevelProject Name
EB-101
SymbolTAG2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)JHSCompletionSamplesGround Surface Elevation (ft)
Grab Sample
3/30/17,3/30/17
Logged by:
Shelby Tube Sample
140# / 30"
Ring Sample
No Recovery
Water Level at time of drilling (ATD)
Lindbergh HS
Project Number
20
Renton, WA
Date Start/Finish
Hammer Weight/Drop
Sampler Type (ST):
Exploration Log
AESIBOR170046.GPJApril20,201762
5050/4"
5050/3"
Asphalt - 3 inches
Fill
Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel;
dark brown inclusion (SM).
Dense, moist, light gray-brown, very silty, fine SAND, trace gravel (SM).
25
50/6"
34
22
19
S-1
S-2
Bottom of exploration boring at 6.5 feet
No visible seepage.
1 of 1
N/A
Sheet
Depth(ft)Exploration Number
170046E001
M - Moisture
6 inches
40
Datum
S
T Graphic10 OtherTestsHole Diameter (in)
DESCRIPTION
Location
Water Level ()Approved by:
30
Blows/Foot
Driller/Equipment
Blows/6"Boretec / Mini-Track
Well5
10
15 WaterLevelProject Name
EB-102
SymbolTAG2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)JHSCompletionSamplesGround Surface Elevation (ft)
Grab Sample
3/30/17,3/30/17
Logged by:
Shelby Tube Sample
140# / 30"
Ring Sample
No Recovery
Water Level at time of drilling (ATD)
Lindbergh HS
Project Number
20
Renton, WA
Date Start/Finish
Hammer Weight/Drop
Sampler Type (ST):
Exploration Log
AESIBOR170046.GPJApril20,20175050/6"
4141
Asphalt - 3 inches
Vashon Lodgement Till
Dense, moist, light gray-brown, very silty, fine SAND, trace gravel;
unsorted; some oxidation; low recovery (SM).
Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel;
unsorted; no oxidation; low recovery (SM).
16
22
25
34
50/5"
S-1
S-2
Bottom of exploration boring at 6 feet
No visible seepage.
1 of 1
N/A
Sheet
Depth(ft)Exploration Number
170046E001
M - Moisture
6 inches
40
Datum
S
T Graphic10 OtherTestsHole Diameter (in)
DESCRIPTION
Location
Water Level ()Approved by:
30
Blows/Foot
Driller/Equipment
Blows/6"Boretec / Mini-Track
Well5
10
15 WaterLevelProject Name
EB-103
SymbolTAG2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)JHSCompletionSamplesGround Surface Elevation (ft)
Grab Sample
3/30/17,3/30/17
Logged by:
Shelby Tube Sample
140# / 30"
Ring Sample
No Recovery
Water Level at time of drilling (ATD)
Lindbergh HS
Project Number
20
Renton, WA
Date Start/Finish
Hammer Weight/Drop
Sampler Type (ST):
Exploration Log
AESIBOR170046.GPJApril20,20174747
5050/5"
Asphalt - 1 inch
Fill
Medium dense, very moist, light gray-brown, silty, fine to medium SAND,
trace gravel (SM).
Vashon Lodgement Till
Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel;
unsorted; some oxidation (SM).
13
10
9
14
28
30
S-1
S-2
Bottom of exploration boring at 6.5 feet
Moderate seepage from 3 feet to bottom of boring.
1 of 1
N/A
Sheet
Depth(ft)Exploration Number
170046E001
M - Moisture
6 inches
40
Datum
S
T Graphic10 OtherTestsHole Diameter (in)
DESCRIPTION
Location
Water Level ()Approved by:
30
Blows/Foot
Driller/Equipment
Blows/6"Boretec / Mini-Track
Well5
10
15 WaterLevelProject Name
EB-104
SymbolTAG2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)JHSCompletionSamplesGround Surface Elevation (ft)
Grab Sample
3/30/17,3/30/17
Logged by:
Shelby Tube Sample
140# / 30"
Ring Sample
No Recovery
Water Level at time of drilling (ATD)
Lindbergh HS
Project Number
20
Renton, WA
Date Start/Finish
Hammer Weight/Drop
Sampler Type (ST):
Exploration Log
AESIBOR170046.GPJApril20,20171919
68
Asphalt - 2 inches
Vashon Lodgement Till
Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel;
unsorted; some oxidation (SM).
Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel;
unsorted, no oxidation; low recovery (SM).
As above.
7
22
31
50/5"
35
50/5"
S-1
S-2
S-3
Bottom of exploration boring at 6 feet
No visible seepage.
1 of 1
N/A
Sheet
Depth(ft)Exploration Number
170046E001
M - Moisture
6 inches
40
Datum
S
T Graphic10 OtherTestsHole Diameter (in)
DESCRIPTION
Location
Water Level ()Approved by:
30
Blows/Foot
Driller/Equipment
Blows/6"Boretec / Mini-Track
Well5
10
15 WaterLevelProject Name
EB-105
SymbolTAG2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)JHSCompletionSamplesGround Surface Elevation (ft)
Grab Sample
3/30/17,3/30/17
Logged by:
Shelby Tube Sample
140# / 30"
Ring Sample
No Recovery
Water Level at time of drilling (ATD)
Lindbergh HS
Project Number
20
Renton, WA
Date Start/Finish
Hammer Weight/Drop
Sampler Type (ST):
Exploration Log
AESIBOR170046.GPJApril20,201753
5050/5"
5050/5"
Asphalt - 2 inches
Vashon Lodgement Till
Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel;
unsorted (SM).
As above.
As above.
12
22
32
30
50/4"
16
33
50/6"
S-1
S-2
S-3
Bottom of exploration boring at 6.5 feet
No visible seepage.
1 of 1
N/A
Sheet
Depth(ft)Exploration Number
170046E001
M - Moisture
6 inches
40
Datum
S
T Graphic10 OtherTestsHole Diameter (in)
DESCRIPTION
Location
Water Level ()Approved by:
30
Blows/Foot
Driller/Equipment
Blows/6"Boretec / Mini-Track
Well5
10
15 WaterLevelProject Name
EB-106
SymbolTAG2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)JHSCompletionSamplesGround Surface Elevation (ft)
Grab Sample
3/30/17,3/30/17
Logged by:
Shelby Tube Sample
140# / 30"
Ring Sample
No Recovery
Water Level at time of drilling (ATD)
Lindbergh HS
Project Number
20
Renton, WA
Date Start/Finish
Hammer Weight/Drop
Sampler Type (ST):
Exploration Log
AESIBOR170046.GPJApril20,201754
5050/4"
83
Asphalt - 2 inches
Vashon Lodgement Till
Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel;
unsorted (SM).
As above.
19
26
31
39
50/5"
S-1
S-2
Bottom of exploration boring at 6 feet
No visible seepage.
1 of 1
N/A
Sheet
Depth(ft)Exploration Number
170046E001
M - Moisture
6 inches
40
Datum
S
T Graphic10 OtherTestsHole Diameter (in)
DESCRIPTION
Location
Water Level ()Approved by:
30
Blows/Foot
Driller/Equipment
Blows/6"Boretec / Mini-Track
Well5
10
15 WaterLevelProject Name
EB-107
SymbolTAG2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)JHSCompletionSamplesGround Surface Elevation (ft)
Grab Sample
3/30/17,3/30/17
Logged by:
Shelby Tube Sample
140# / 30"
Ring Sample
No Recovery
Water Level at time of drilling (ATD)
Lindbergh HS
Project Number
20
Renton, WA
Date Start/Finish
Hammer Weight/Drop
Sampler Type (ST):
Exploration Log
AESIBOR170046.GPJApril20,201757
5050/5"
Asphalt - 2.5 inches
Gravel Base Course
Clean, angular, 1/4-inch base course aggregate (GP).
Fill
Loose, moist, dark brown, silty, fine to medium SAND, some gravel;
unsorted; contains organics (SM).
Loose, moist, light brown, silty, fine SAND, some gravel; contains woody
debris (3 inch diameter); unsorted (SM).
Vashon Lodgement Till
Very dense, moist, brownish gray, silty, fine SAND, some gravel; unsorted;
digs up in clasts (SM).
S-1
S-2
S-3
S-4
Bottom of exploration boring at 4 feet
No groundwater encountered.
Ground Surface Elevation (ft)
Grab SampleSymbol 5
40
Datum
Hammer Weight/Drop
Sampler Type (ST):
~434
5
HB-3
Ring Sample
No RecoveryGraphic 10 OtherTestsHole Diameter (in)
DESCRIPTION
Driller/Equipment
Blows/6"JHS
ART2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)WaterLevelProject Name
Water Level ()Approved by:
30
Blows/Foot
SamplesDepth(ft)S
T
Exploration Number
20000669E005
12/3/21,12/3/21
Logged by:
Shelby Tube Sample
Hand Auger
Exploration Boring
Water Level at time of drilling (ATD)
Lindbergh High School Additions
M - Moisture
Project Number
20
Renton, WA
Date Start/Finish
CompletionLocation
Sheet
1 of 1
NAVD 88
WellAESIBOR20000669E005.GPJDecember30,2021
Asphalt - 1.75 inches
Gravel Base Course
Dense, moist, grayish brown, fine to medium sandy, GRAVEL, some silt;
unsorted; gravel is angular (GP-GM).
Vashon Lodgement Till
Very dense, moist, brownish gray, silty, fine SAND, some gravel; unsorted;
digs up in clasts (SM).
Iron oxide mottling 0 to 1 foot.
S-1
S-2
Bottom of exploration boring at 2.5 feet
No groundwater encountered. Refusal due to large cobble.
Ground Surface Elevation (ft)
Grab SampleSymbol 5
40
Datum
Hammer Weight/Drop
Sampler Type (ST):
~432
5
HB-4
Ring Sample
No RecoveryGraphic 10 OtherTestsHole Diameter (in)
DESCRIPTION
Driller/Equipment
Blows/6"JHS
ART2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)WaterLevelProject Name
Water Level ()Approved by:
30
Blows/Foot
SamplesDepth(ft)S
T
Exploration Number
20000669E005
12/3/21,12/3/21
Logged by:
Shelby Tube Sample
Hand Auger
Exploration Boring
Water Level at time of drilling (ATD)
Lindbergh High School Additions
M - Moisture
Project Number
20
Renton, WA
Date Start/Finish
CompletionLocation
Sheet
1 of 1
NAVD 88
WellAESIBOR20000669E005.GPJDecember30,2021
Asphalt - 2.25 inches
Base Course
Dense, moist to wet, grayish brown, fine to medium gravelly, SAND, some
coarse sand, trace silt; unsorted (SP).
Fill
Loose, moist, dark brown, silty, fine SAND, some gravel, trace cobbles;
contains shredded wood debris; unsorted (SM).
Vashon Lodgement Till
Very dense, moist, gray, silty, fine SAND to fine sandy, SILT, some gravel;
occasional cobbles; unsorted (SM).
S-1
S-2
S-3
Bottom of exploration boring at 3 feet
Slow groundwater seepage ~3 to 6 inches. Refusal due to large cobbles.
Ground Surface Elevation (ft)
Grab SampleSymbol 5
40
Datum
Hammer Weight/Drop
Sampler Type (ST):
~430
5
HB-5
Ring Sample
No RecoveryGraphic 10 OtherTestsHole Diameter (in)
DESCRIPTION
Driller/Equipment
Blows/6"JHS
ART2" OD Split Spoon Sampler (SPT)
3" OD Split Spoon Sampler (D & M)WaterLevelProject Name
Water Level ()Approved by:
30
Blows/Foot
SamplesDepth(ft)S
T
Exploration Number
20000669E005
12/3/21,12/3/21
Logged by:
Shelby Tube Sample
Hand Auger
Exploration Boring
Water Level at time of drilling (ATD)
Lindbergh High School Additions
M - Moisture
Project Number
20
Renton, WA
Date Start/Finish
CompletionLocation
Sheet
1 of 1
NAVD 88
WellAESIBOR20000669E005.GPJDecember30,2021
Particle Size Distribution Report
PERCENT FINER0
10
20
30
40
50
60
70
80
90
100
GRAIN SIZE - mm.
0.0010.010.1110100
% +3"Coarse
% Gravel
Fine Coarse Medium
% Sand
Fine Silt
% Fines
Clay
0.0 0.0 22.7 9.0 15.4 27.7 25.26 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200TEST RESULTS
Opening Percent Spec.*Pass?
Size Finer (Percent) (X=Fail)
Material Description
Atterberg Limits (ASTM D 4318)
Classification
Coefficients
Date Received:Date Tested:
Tested By:
Checked By:
Title:
Date Sampled:Location: Onsite - FillSample Number: HB-5 Depth: 1'
Client:
Project:
Project No:Figure
gravelly, silty SAND
1"
3/4"
5/8"
1/2"
3/8"
#4
#8
#10
#20
#40
#60
#100
#200
100.0
100.0
97.7
93.5
85.6
77.3
69.8
68.3
60.8
52.9
43.8
34.8
25.2
NP NV
SM A-2-4(0)
11.1732 9.2723 0.7830
0.3531 0.1083
12/9/2021 12/13/2021
CI
ART/BG
12/3/2021
Renton School District No. 403
Lindbergh HS Improvements
20000669 E005
PL=LL=PI=
USCS (D 2487)=AASHTO (M 145)=
D90=D85=D60=
D50=D30=D15=
D10=Cu=Cc=
Remarks
*(no specification provided)
Particle Size Distribution Report
PERCENT FINER0
10
20
30
40
50
60
70
80
90
100
GRAIN SIZE - mm.
0.0010.010.1110100
% +3"Coarse
% Gravel
Fine Coarse Medium
% Sand
Fine Silt
% Fines
Clay
0.0 9.0 20.2 6.8 15.5 26.9 21.66 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200TEST RESULTS
Opening Percent Spec.*Pass?
Size Finer (Percent)(X=Fail)
Material Description
Atterberg Limits (ASTM D 4318)
Classification
Coefficients
Date Received:Date Tested:
Tested By:
Checked By:
Title:
Date Sampled:Location: Onsite - TillSample Number: HB-4 Depth: 2'
Client:
Project:
Project No:Figure
gravelly, silty SAND
1.5"
1"
3/4"
5/8"
1/2"
3/8"
#4
#8
#10
#20
#40
#60
#100
#200
100.0
94.5
91.0
82.3
81.1
78.4
70.8
65.1
64.0
58.0
48.5
37.3
29.0
21.6
NP NV
SM A-1-b
18.6381 16.9262 1.0891
0.4616 0.1613
12/9/2021 12/13/2021
CI
ART/BG
12/3/2021
Renton School District No. 403
Lindbergh HS Improvements
20000669 E005
PL=LL=PI=
USCS (D 2487)=AASHTO (M 145)=
D90=D85=D60=
D50=D30=D15=
D10=Cu=Cc=
Remarks
*(no specification provided)
Particle Size Distribution Report
PERCENT FINER0
10
20
30
40
50
60
70
80
90
100
GRAIN SIZE - mm.
0.0010.010.1110100
% +3"Coarse
% Gravel
Fine Coarse Medium
% Sand
Fine Silt
% Fines
Clay
0.0 8.3 10.4 6.3 15.4 26.9 32.76 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200TEST RESULTS
Opening Percent Spec.*Pass?
Size Finer (Percent)(X=Fail)
Material Description
Atterberg Limits (ASTM D 4318)
Classification
Coefficients
Date Received:Date Tested:
Tested By:
Checked By:
Title:
Date Sampled:Location: Onsite - TillSample Number: HB-5 Depth: 2.5'
Client:
Project:
Project No:Figure
gravelly, very silty SAND
1.5"
1"
3/4"
5/8"
1/2"
3/8"
#4
#8
#10
#20
#40
#60
#100
#200
100.0
94.1
91.7
91.7
90.8
87.5
81.3
76.2
75.0
68.9
59.6
48.4
40.0
32.7
NP NV
SM A-2-4(0)
11.6794 7.5175 0.4349
0.2707
12/9/2021 12/13/2021
CI
ART/BG
12/3/2021
Renton School District No. 403
Lindbergh HS Improvements
20000669 E005
PL=LL=PI=
USCS (D 2487)=AASHTO (M 145)=
D90=D85=D60=
D50=D30=D15=
D10=Cu=Cc=
Remarks
*(no specification provided)