GEOTECH REPORT V1Geotechnical Engineering Services Report
Proposed Ustick Multifamily Development
Meridian, Idaho
For
Phoenix Commercial Construction
April 8, 2019
Geotechnical Engineering Services Report
Proposed Ustick Multifamily Development
Meridian, Idaho
for
Phoenix Commercial Construction
April 8, 2019
GEOENGINEERS�
3501 West Elder Street, Suite 300
Boise, Idaho 83705
208.433.8098
Geotechnical Engineering Services
Proposed Ustick Multifamily Development
Meridian, Idaho
File No. 23820-001-00
April 8, 2019
Prepared for:
Phoenix Commercial Construction
1307 N 39th Street
Nampa, Idaho 83687
Attention: Shannon Robnett
Prepared by:
GeoEngineers, Inc.
3501 West Elder Street, Suite 300
Boise, Idaho 83705
208.433.8098
Rachel A. Hunt, PG
Geologist
Greg A. andau, PE (Oregon)
Associate
RMH:BPD:GAL:mis
n P. DuRee, PE
Senior Engineer
Disclaimer: Any electronic form, facsimile or hard copy of the original document (email, text, table, and/or figure), if provided, and any attachments are only a copy
of the original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record.
GMENGINEERS�
INTRODUCTION........................................................................................................................................................... 1
SCOPEOF SERVICES.................................................................................................................................................. 1
FIELD EXPLORATIONS AND LABORATORY TESTING............................................................................................... 1
SITECONDITIONS........................................................................................................................................................ 1
Geology.................................................................................................................................................................1
SurfaceConditions...............................................................................................................................................2
SiteConditions..............................................................................................................................................2
SubsurfaceConditions........................................................................................................................................2
General..........................................................................................................................................................2
GroundwaterConditions......................................................................................................................................3
CONCLUSIONS AND RECOMMENDATIONS.............................................................................................................. 3
EarthquakeEngineering......................................................................................................................................4
General..........................................................................................................................................................4
GroundShaking.............................................................................................................................................4
Liquefaction...................................................................................................................................................5
GroundSurface Rupture...............................................................................................................................5
LateralSpreading..........................................................................................................................................5
ShallowFoundations...........................................................................................................................................5
General..........................................................................................................................................................
5
FoundationDesign........................................................................................................................................5
FootingDrains...............................................................................................................................................6
Construction Considerations........................................................................................................................7
Slab -on -Grade Floors...........................................................................................................................................7
SubgradePreparation...................................................................................................................................7
DesignConsiderations..................................................................................................................................7
RetainingWalls....................................................................................................................................................7
DesignParameters.......................................................................................................................................8
WallDrainage................................................................................................................................................8
Pavement.............................................................................................................................................................8
General..........................................................................................................................................................
8
SubgradePreparation...................................................................................................................................9
HotMix Asphalt Pavement...........................................................................................................................9
PCCPavement...............................................................................................................................................9
StormwaterInfiltration.........................................................................................................................................9
General..........................................................................................................................................................
9
TestProcedure..............................................................................................................................................9
INF-1 Test Data Summary .........................................................................................................................
10
INF-2 Test Data Summary .........................................................................................................................
11
InfiltrationDesign Rates............................................................................................................................
12
Earthwork..........................................................................................................................................................
12
ExcavationConsiderations........................................................................................................................
12
Clearing and Site Preparation...................................................................................................................
13
SubgradePreparation................................................................................................................................
13
Excavation Considerations........................................................................................................................
13
GEOENGINEERS� April8, 2019 Page i
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ImportedFill Materials............................................................................................................................... 14
Reuseof On -site Soils................................................................................................................................ 14
Fill Placement and Compaction Criteria................................................................................................... 14
UtilityTrenches........................................................................................................................................... 15
Erosion and Sediment Control.................................................................................................................. 15
WeatherConsiderations............................................................................................................................ 15
Recommended Additional Geotechnical Services.......................................................................................... 16
LIMITATIONS.............................................................................................................................................................16
REFERENCES............................................................................................................................................................17
LIST OF FIGURES
Figure 1. Vicinity Map
Figure 2. Site Plan
APPENDICES
Appendix A. Field Explorations
Figure A-1—Key to Exploration Logs
Figures A-2 through A-9—Logs of Test Pits
Appendix B. Laboratory Testing
Figures B-1 and B-2—Sieve Analysis Results
Figure B-3—Atterberg Limits Test Results
Appendix C. Report Limitations and Guidelines for Use
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INTRODUCTION
This report presents the results of GeoEngineers, Inc. (GeoEngineers) geotechnical evaluation of the
proposed Ustick Multifamily Development to be located on Parcel No. S1201121103 at 745 West Ustick
Road in Meridian, Idaho. The subject property and surrounding physical features are shown in Figure 1,
Vicinity Map and Figure 2, Site Plan.
We understand the project includes constructing multiple new apartment buildings on the site. The size
and locations of the buildings have not been finalized yet, but a conceptual layout is shown in Figure 2. We
understand the buildings will be constructed as at -grade three-story units. We anticipate sidewalk, parking
lot and access drives will be constructed throughout the site.
SCOPE OF SERVICES
The purpose of our services is to provide geotechnical engineering support for development of the proposed
project. Our services have been completed in general accordance with the scope presented in our proposal
dated February 8, 2019 and executed on February 20, 2019. Our scope of services included:
■ Completing geotechnical explorations and infiltration testing.
■ Geotechnical laboratory testing.
■ Engineering analysis.
■ Preparing this report.
FIELD EXPLORATIONS AND LABORATORY TESTING
We evaluated the subsurface conditions at the site by observing eight test pit excavations (TP-1 through
TP-6, INF-1, and INF-2) which were excavated to depths between 9 and 12 feet below existing site grades.
We completed infiltration tests within test pits INF-1 and INF-2 at a depth of 3.5 feet and 5.0 feet below
ground surface (bgs), respectively. The approximate locations of the test pits are shown in Figure 2. Details
of the field exploration program and the test pit logs are presented in Appendix A, Field Explorations.
Soil samples obtained during excavating were taken to our laboratory for further evaluation. Selected
samples were tested for moisture content, percent passing the No. 200 sieve, grain -size distribution, and
Atterberg limits determination. A description of the laboratory testing and the test results are presented in
Appendix B.
SITE CONDITIONS
Geology
The site is located in the Western Snake River Plain of the Columbia Plateau Province, a northwest -trending
structural basin bounded by high angle faults of Miocene (23 to 5 million years ago) and younger age. The
basin separates the mountains of the Idaho Batholith on the northeast and the Owyhee Range on the
southwest. Sedimentary deposits of stream and lake depositional environments shed from adjacent
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uplands, as well as basaltic and andesitic flows and ash deposits associated with regional volcanic activity,
fill the basin to depths exceeding 4,000 feet (Othberg, 1994).
The mapped geology atthe site is Gravel of the Whitney Terrace (Othbergand Stanford, 1992). These gravel
deposits are described as sandy pebble and cobble gravel that are typically mantled with 3 to 7 feet of
fine-grained wind-blown deposits, known as loess. The gravel deposits are a part of a sequence of terraces
that were formed by the ancestral Boise River. The characteristic coarse channel gravels were deposited
on Tertiary fine-grained sediments. The gravels are composed of mostly granitic and felsitic clasts, with
occasional basalt clasts. The terrace gravel deposits are well-rounded, well graded, and have crude
stratification of beds of gravels and lenses of cross -bedded sand. The soil observed in the test pit
excavations was generally consistent with the mapped geology.
Surface Conditions
Site Conditions
The site is approximately 14.6 acres and is currently being used as pasture for animals with one residential
structure and several outhouse structures located near West Ustick Road. The site is bordered by West
Ustick Road to the north; North Venable Lane to the west; a neighborhood of single-family homes to the
south; and pasture land with one residential structure to the east. The ground surface is relatively flat. A
site survey with topography was not available at the time of preparing this report. Vegetation on the site is
limited to grass and weeds with trees located along the driveway of the residential structure. General site
conditions can be seen on the aerial photograph in Figure 2.
Subsurface Conditions
General
We observed native fine-grained loess deposits, transitional clayey/silty gravel soils, and sand and gravel
deposits. We observed 5 to 8 inches of topsoil containing organic matter and roots at each test pit location.
A description of each of these soil units is presented below and the depth at which these soil units were
encountered is presented in Table 1.
■ Loess Deposits. We observed approximately 11/2 to 41/2 feet native loess deposits in each test pit. These
deposits consist of medium stiff to very stiff lean clay and silt with variable sand content. We probed
this layer with a 1/2-inch-diameter steel probe rod and observed probe depths typically ranging between
1/2 to 11/2 inches. Pocket penetrometer measurements of the test pit sidewalls ranged from 0.5 to
2.5 tons per square foot (tsf) in this soil unit. Portions of these deposits were observed to be slightly to
strongly cemented.
■ Transitional Deposits. Underlying the loess deposits, we observed a transitional zone between the
loess and gravel deposits in TP-3 through TP-6, INF-1, and INF-2. This unit is composed of dense to very
dense clayey or silty fine to coarse gravel with sand, and where present, extended to depths ranging
between 3 and 6 feet bgs. Portions of these deposits were observed to be slightly to strongly cemented.
Probe rod depths in this layer ranged between 1/2 to 11/2 inches.
■ Sand Gravel Deposits. We observed terrace gravel deposits in all test pits to depths explored. These
deposits consist of dense to very dense fine to coarse gravel with silt and sand to dense fine to coarse
sand with gravel. Occasional cobbles were observed in some of the test pits.
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TABLE 1. SUMMARY OF OBSERVED SOIL CONDITIONS
Test Pit
ID
Loess Deposits
TP-1
Surface to 31/2 feet
TP-2
Surface to 4 feet
TP-3
3 feet
TP-4
41/2 feet
TP-5
21/2 feet
TP-6
3 feet
INF-1
11/2 feet
INF-2
4 feet
Soil Unit Depth
Transitional Deposits
Sand and Gravel Deposits
Not present
31/2 feet to bottom of test pit (11 feet below grade)
Not present
4 feet to bottom of test pit (91/2 feet below grade)
3 feet to 5 feet
5 feet to bottom of test pit (11 feet below grade)
41/2 feet to 6 feet
6 feet to bottom of test pit (11 feet below grade)
21/2 feet to 51/2 feet
51/2 feet to bottom of test pit (101/2 feet below grade)
3 feet to 51/2 feet
51/2 feet to bottom of test pit (11 feet below grade)
11/2 feet to 3 feet
3 feet to bottom of test pit (9 feet below grade)
4 feet to 6 feet
6 feet to bottom of test pit (12 feet below grade)
Groundwater Conditions
Groundwater was encountered at 6 to 8 feet bgs within the test pit excavations. These groundwater levels
should be considered approximate and should be expected to fluctuate with the weather and seasons. A
summary of the depths to groundwater is presented in Table 2.
TABLE 2. SUMMARY OF OBSERVED GROUNDWATER CONDITIONS
Test Pit ID
Depth to groundwater (feet below grade)
TP-1
7
TP-2
61/2
TP-3
61/2
TP-4
61/2
TP-5
6
TP-6
6
INF-1
5
INF-2
8
CONCLUSIONS AND RECOMMENDATIONS
A summary of our conclusions and primary geotechnical considerations is provided below. The summary is
presented for introductory purposes only and should be used in conjunction with the complete
recommendations presented in this report.
■ Our recommendations are based on the City of Meridian Code, the 2015 International Building Code
(IBC), and the 2017 Edition of the Idaho Standard for Public Works Construction (ISPWC) manual as
amended by the City of Meridian.
■ The site is designated as Soil Profile Type D per the 2015 IBC.
■ The site has a low liquefaction, lateral spreading, and fault rupture potential.
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■ The proposed building may be supported on shallow spread footings. Footings may be sized using an
allowable bearing pressure of 2,500 pounds per square foot (psf) if supported on the native silt and
clay loess deposits or structural fill extending to these deposits. If needed, the allowable bearing
pressure can be increased to 4,000 psf if the silt and clay loess deposits are removed and replaced
with structural fill. Based on data from the test pits, this could require excavating up to 4 feet below
existing site grades. The structural fill should extend beyond the edges of the foundation a distance
equal to half of the fill thickness below the footing. Lateral resistance of foundations may be provided
using an allowable coefficient of friction of 0.35 and an allowable passive resistance of 300 pcf.
■ Slab -on -grade floors may be supported on compacted native soils or on structural fill overlying native
soils as described in this report.
■ The on -site soils may be reused as structural fill depending on the time of year, provided it can be
moisture conditioned to within 3 percent of the optimum moisture content and compacted to the
minimum requirements.
■ Infiltration testing was completed in test pits INF-1 and INF-2 at depths of 3.5 and 5 feet below existing
site grades, respectively. Based on site conditions, test methods used, and a factor of safety of 2.0, we
recommend a maximum design infiltration rate of 2.5 inches per hour in the uncemented sand/gravel
with silt. This design rate is reduced to 0.35 where the sand and gravel layers are cemented.
Our specific geotechnical recommendations are presented in the following sections of this report.
Earthquake Engineering
General
We evaluated the site for seismic hazards including liquefaction, lateral spreading, ground surface rupture,
and ground shaking. Our evaluation indicates the site has a low risk of liquefaction, lateral spreading, and
surface rupture. A summary of the evaluation for each hazard is presented below.
Ground Shaking
The City of Meridian, Idaho has currently adopted the 2015 version of the IBC. The mapped 2015 IBC
seismic parameters for the project site are presented in Table 3.
TABLE 3. 2015 IBC SEISMIC DESIGN PARAMETERS
IBC Parameter
Site Class
Peak Ground Acceleration, PGA (percent g)
Site Modified Peak Ground Acceleration, PGAM (percent g)
Short Period Spectral Response Acceleration, Ss (percent g)
1-Second Period Spectral Response Acceleration, Si (percent g)
Seismic Coefficient, FA
Seismic Coefficient, Fv
Note:
Latitude 43.632503' and Longitude-116.402353'
Recommended Value
D
0.115
0.181
0.293
0.103
1.566
2.388
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Liquefaction
Liquefaction refers to the condition by which vibration or shaking of the ground, usually from earthquake
forces, results in the development of excess pore pressures in saturated soils with subsequent loss of
strength. Ground settlement, lateral spreading and/or sand boils may result from soil liquefaction.
Structures supported on liquefiable soils could suffer foundation settlement or lateral movement during
ground shaking that could be severely damaging to structures. In general, soils that are susceptible to
liquefaction include very loose to medium dense, clean to silty sands that are below the water table. These
soil and groundwater conditions were not observed in our test pits completed at the site. It is our opinion
the risk of liquefaction at the site is low and does not warrant further design consideration.
Ground Surface Rupture
We reviewed the potential for ground surface fault rupture by reviewingthe USGS fault fold online database.
Based on our review, the site is located approximately 3 miles north and east of the Western Snake River
Plain fault system which are of the undifferentiated Quaternary age (less than 1.8 million years). The closest
mapped active fault from the Holocene period (less than 11,650 years) is the Squaw Creek Fault which is
located about 21 miles north of the site. Based on the site location with respect to the nearest known active
fault, it is our opinion that the risk of ground rupture at the site resulting from surface faulting is low and
does not warrant further design considerations.
Lateral Spreading
Lateral spreading can occur where liquefiable soils are present on sloping ground. Due to the mapped
seismic information and the site's topography, the risk of adverse impacts resulting from seismically
induced lateral spreading is considered to be low and does not warrant further design considerations.
Shallow Foundations
General
In our opinion, proposed structures at the site may be supported on shallow foundations, provided the
foundation is designed and supported as recommended below.
Foundation Design
Bearing Capacity
The foundations may be designed for the following two conditions:
■ Foundations supported on native stiff to very stiff loess deposits or on structural fill extending to these
deposits using an allowable bearing pressure of 2,500 psf.
■ Foundations may be designed using a higher bearing capacity of 4,000 psf if the native silt and clay
loess deposits are removed and replaced with compacted structural fill.
All structural fill placed below foundations should extend horizontally beyond the edge of the foundation by
a distance equal to the half of thickness of the fill.
We recommend thatfoundation subgrade preparation, foundation excavations and structural fill placement
be observed by a representative from our firm to verify that the procedures comply with the intent of our
recommendations and the project plans and specifications.
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Foundation Geometry
We recommend minimum footing widths of 18 inches for continuous wall footings and 24 inches for
isolated column footings.
Foundations which are susceptible to frost/thaw movements should extend below the frost depth, which is
estimated to be 24 inches in Meridian, Idaho; therefore, we recommend the exterior footings be founded
at least 24 inches below finished grade and interior footings (in heated building areas) be founded at least
12 inches below bottom of slab or adjacent finished grade. Interior foundations poured monolithically with
the floor slab should be founded at least 8 inches below the top of the slab.
Settlement
Provided the foundations are supported properly as recommended above, we estimate the total settlement
of shallow foundations will be about 1 inch or less. The settlements will occur rapidly, essentially as the
loads are applied. Differential settlements between footings or along a 20-foot-long section of continuous
footing could be half the total settlement. Note that less settlement will result from lower applied loads,
which could result in increased differential settlement between variable foundation loads.
Lateral Resistance
Lateral foundation loads may be resisted by passive resistance on the sides of footings and by friction on
the base of the footings. Frictional resistance may be calculated using an allowable coefficient of friction
of 0.35 applied to vertical dead -load forces.
The allowable passive resistance may be computed using an equivalent fluid density of 300 pcf. Caution
should be taken if excavations can be made adjacent to foundations supporting lateral loads. We
recommend passive resistance be neglected where potential future excavations could occur along
foundations. These values are appropriate for foundation elements that are poured directly against
undisturbed native deposits or surrounded by properly placed and compacted structural fill.
The above coefficient of friction and passive equivalent fluid density values incorporate a factor of safety
of about 1.5.
Footing Drains
Footing drains are often not installed around at -grade buildings in Southern Idaho. The site soils contain an
appreciable amount of siltand are anticipated to have a relativelyslow infiltration rate. While not necessary,
it is our opinion that perimeter footing drains will reduce the risk of moisture through the floor slab due to
the low permeable soils at the site.
If used, the drains should consist of 4-inch-diameter perforated collector pipe enveloped within a minimum
thickness of 6 inches of gravel as described in the "Structural Fill" section of this report. The gravel backfill
should be wrapped with a non -woven geotextile meeting the requirements for Type II Drainage Geotextile
of Section 2050 of the ISPWC.
We recommend using either heavy -wall solid pipe (SDR-35 polyvinyl chloride [PVC]) or rigid corrugated
polyethylene pipe (ADS N-12 or equivalent) for the collector pipe. We recommend against using flexible
tubing for footing drainpipe.
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The pipes should be laid with a minimum slope of 1/2 percent and discharge into an appropriate outfall.
The pipe installations should include a cleanout riser with cover located at the upper end of each pipe run.
We recommend that the cleanouts be covered and be placed in flush -mounted utility boxes or monuments.
The foundation drainpipes should be located near the base of perimeter strip footings.
Permanent drainage systems should intercept surface water runoff at the top and/or bottom of cut and fill
slopes to prevent runoff from flowing in an uncontrolled manner across the site. The finished ground
surface adjacent to new and existing buildings should be sloped so that surface water runoff flows away
from the structures and the nearby slopes. Roof drains should be tightlined to an appropriate discharge
point and should not be connected to the footing drains.
Construction Considerations
All soft or loose soil, frozen soil, standing water, debris and other unsuitable soil should be removed from
the foundation excavations prior to placing reinforcement steel and concrete. Following over -excavation of
unsuitable soil, the resulting void should be backfilled with compacted structural fill, as specified in the
Earthwork section of this report. Unsuitable material not removed from foundation subgrade areas can
results in increased foundation settlement.
Slab -on -Grade Floors
Subgrade Preparation
We recommend slab -on -grade floors be supported on undisturbed, firm native soil or on structural fill
overlying native soil. Soft, wet or disturbed soil and areas identified during construction should be excavated
to a depth of 12 inches or firm bearing, whichever is less, and replaced with imported structural fill as
defined in a following section. If subgrade is still soft or wet following overexcavation, a non -woven geotextile
meeting the criteria of a Type III subgrade separation geotextile in Section 2050 of the ISPWC standards
should be placed on top of exposed subgrade soil.
Design Considerations
We recommend conventional slab -on -grade floors be supported on 6 inches of capillary break material.
Capillary break should consist of 2-inch (Type II) crushed aggregate per ISPWC, Section 802. Avapor barrier
should be included in design. The slab will be supported by soils which could have variable characteristics.
Including one layer of reinforcement steel would help bridge any softer areas and prevent vertical
displacements should cracking occur. A two-way slab would provide more resistance to displacements and
cracking.
Retaining Walls
Retaining walls used to achieve grade transitions or for landscaping, can be constructed using traditional
structural systems such as reinforced concrete and concrete masonry unit (CMU) blocks, or mechanically
stabilized earth (MSE) walls with wire or block facing units. Non-structural systems such as rockeries may
also be used to achieve grade transitions.
The following recommendations should be used for the design of retaining walls that are used to achieve
grade changes. These recommendations are for walls shorter than about 10 feet in height. Our
recommendations should be updated if walls taller than 10 feet are planned. We can provide additional
design recommendations for retaining structures, if requested.
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Design Parameters
Lateral earth pressures for design of retaining structures should be evaluated using an equivalent fluid
density of 35 pcf provided that the walls will not be restrained against rotation when backfill is placed. If
the walls will be restrained from rotation, we recommend using an equivalent fluid density of 55 pcf. Walls
are assumed to be restrained if top movement during backfilling is less than H/1000, where H is the wall
height. These lateral soil pressures assume that the ground surface behind the wall is horizontal. For
unrestrained walls with backfill sloping up at 2H:1V (horizontal:vertical), the design lateral earth pressure
should be increased to 55 pcf, while restrained walls with a 2H:1V sloping backfill should be designed using
an equivalent fluid density of 75 pcf. These lateral soil pressures do not include the effects of surcharges
such as foundation/floor loads, traffic loads or other surface loading. An equivalent fluid density lateral
seismic earth pressure of 8 pcf should be added to the static earth pressures for seismic evaluation.
If vehicles can approach the tops of retaining walls to within one-half the height of the wall, a traffic
surcharge should be added to the wall pressure. For car parking areas, the traffic surcharge can be
approximated by the equivalent weight of an additional 1 foot of soil backfill (125 psf) behind the wall. For
delivery truck parking areas and access driveway areas, the traffic surcharge can be approximated by the
equivalent weight of an additional 2 feet (250 psf) of soil backfill behind the wall.
These recommendations are based on the assumption that adequate drainage will be provided behind
below -grade walls and retaining structures as discussed below. The values for soil bearing, frictional
resistance, and passive resistance presented above for foundation design are applicable to retaining wall
design. Walls located in level ground areas should be founded at a depth of 24 inches below the adjacent
grade.
Wall Drainage
Positive drainage should be provided behind retainingwalls by placing a minimum 2-foot-wide zone of drain
rock directly behind the wall. The drain rock should extend from the base of the wall to within 2 feet of the
finished ground surface. In unpaved areas, the top 2 feet of fill should consist of relatively impermeable
soil, such as on -site silty or clayey soils or topsoil, to prevent infiltration of surface water into the wall
drainage zone.
A 4-inch-diameter perforated drainpipe should be installed within the free -draining material at the base of
each wall. We recommend against using flexible tubing for the wall drainpipe.
The pipes should be laid with minimum slopes of one-half percent and discharge into the stormwater
collection system to convey the water off -site. The pipe installations should include a cleanout riser with
cover located at the upper end of each pipe run. The cleanouts could be placed in flush -mounted access
boxes. Collected downspout water should be routed to appropriate discharge points in separate pipe
systems.
Pavement
General
Specific traffic loading information for pavement design was not provided. Our standard pavement
recommendations for flexible HMA and portland cement concrete (PCC) sections are provided in the
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sections below. Our recommendations are based on assumed typical loading conditions for the anticipated
development. A specific pavement design can be provided by GeoEngineers, upon request.
Subgrade Preparation
We recommend subgrade soils in new pavement areas be adequately prepared prior to placement of base
course. We recommend that the existing fill soils exposed at the subgrade be compacted to a firm,
non -yielding condition with a minimum 95 percent of the MDD. If the subgrade does not meet these criteria,
we recommend that 12 inches of imported structural fill as described in a following section be placed below
the crushed aggregate base course. Evaluation of subgrade conditions should be accomplished through
visual observations of proof -rolling and/or probing.
Hot Mix Asphalt Pavement
We recommend flexible HMA pavement consist of at least 3 inches of HMA placed over 6 inches crushed
aggregate base course. For a shorter design life, or if increased pavement cracking is acceptable in the
parking lot, the HMA thickness could be reduced to 2.5 inches. Asphalt should meet the requirements of
ISPWC, Section 810 Class III plant mix and be placed in accordance with ISPWC standard specifications.
PCC Pavement
PCC pavement may be utilized for areas of concentrated, repetitive loading conditions, such as loading
docks, dumpster pad areas and for ingress/egress aprons. Dumpster pads should be large enough to
support the container and tipping axle of the dumpster truck. We recommend these pavements consist of
at least 6 inches of PCC over 6 inches of crushed aggregate base course. If the concrete section will have
doweled joints, we recommend the concrete thickness be increased by an amount equal to the diameter
of the dowels.
Stormwater Infiltration
General
We understand stormwater infiltration is being considered as part of the design of the project. We
completed infiltration testing at two locations to support stormwater design. The results of our infiltration
tests and recommended infiltration rates are provided below.
Test Procedure
We completed a pilot infiltration test (PIT) within two test pits, INF-1 and INF-2. For each PIT, a graduated
PVC pipe was driven into the floor of the test pit as a visual reference for monitoring water levels during
testing. A piezoelectric pressure transducer was secured to the bottom of the PVC pipe to provide accurate
water level records in 10-second intervals throughout the duration of the tests.
Initial filling and maintaining of the water levels in each test pit were performed by measuring inflow and
water level during the "pre-soak" period. The test pit was filled to maintain a water depth of about 14 to
15 inches during the pre-soak period until the infiltration rate was observed to have stabilized. After the
pre-soak period, the test was continued for an additional 30 to 60 minutes during the "steady-state" period
to monitor the infiltration rate. During the pre-soak and steady-state periods, the water level was allowed
to drop approximately 2 inches before the pit was refilled to the initial level again to maintain a minimum
water depth of about 14 inches. The infiltration rate was measured based on the measured 2-inch
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fallinghead period. After the steady-state period, the water was turned off and the water level was recorded
for one hour or until the test pit was drained. Due to the slow infiltration rate in test pit INF-2, this procedure
was limited to just a few cycles. A summary of each PIT is presented below.
INF-1 Test Data Summary
We completed a test pit infiltration test in test pit INF-1 located on the southwestern portion of the site at
a depth of about 31/2 feet below existing site grade. The test was completed within a soil unit classified as
fine to coarse sand with silt and gravel (SP-SM) with fines (silt- and clay -sized particles passingthe U.S. No.
200 sieve) content of 11 percent. The base area of test pit INF-1 was approximately 4 feet by 4 feet (base
area of about 16 square feet). The measured head duringtesting is presented in Chart 1 and the calculated
infiltration rate for each test stage is presented in Chart 2.
1.50
1.25
d
t 1.00
3
0.25
0.00
\1
10
9.5
9
8.5
8
7.5
7
6.5
� 6
5.5
5
c
L5
s 4
3.5
c 3
2.5
2
1.5
1
0.5
0
—Raw Data
4;
Chart 1. Measured head during PIT in INF-1
3
tia
yo9
Chart 2. Calculated Infiltration Rate in INF-1
Analyzed Section
-y
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File No. 23820-001-00
INF-2 Test Data Summary
Infiltration attest pit INF-2 was completed at a depth of about 5 feet below existing site grade. The test at
test pit INF-2 was completed within a soil unit classified as fine to coarse gravel with silt and sand (GP -GM)
with fines (silt- and clay -sized particles passing the U.S. No. 200 sieve) content of 11 percent. It should be
noted that the soil was observed to be strongly cemented at the test elevation depth. The base area of test
pit INF-2 at the test depths was approximately 4 feet by 4 feet (base area of about 16 square feet). The
measured head duringtesting is presented in Chart 3 and the calculated infiltration rate for each test stage
is presented in Chart 4.
3.00
A
9
2.50
1.50
0.50
5
4.5
4
3.5
s 3
c
2.5
c
0
2
1.5
1
0.5
0
—Raw Data
Analyzed Section
fp a ti a
`1t1 9ti`O� 9ti� y 9titi1 10°, 1o'R 10'' ,o�yry off^ 10°�
Chart 3. Measured head during PIT in INF-2
0
1L 00 tW ° tiP y c0 NO. 30 ,tiP yL 00
$\11 c `b\1 \1 b\1 q\1
Chart 4. Calculated Infiltration Rate in INF-2
GEOENGINEERSJ
April 8, 2019 Page 11
File No. 23820-001-00
Infiltration Design Rates
Based on site conditions and test methods used, we recommend a factor of safety of at least 2.0 be applied
to the measured infiltration rate. Our measured and recommended infiltration rates for the project are
based on the infiltration test and are presented in Table 4.
TABLE 4. RECOMMENDED DESIGN INFILTRATION RATES
Maximum Design
Test Pit
Measured Infiltration
Factor of
Infiltration Rate
ID
Subgrade Soil Conditions
Rate (inches/hour)
Safety
(inches/hour)
Fine to coarse sand with silt and
INF-1
5.0
2.0
2.5
gravel (SP-SM)
Cemented fine to coarse gravel
INF-2
0.7
2.0
0.35
with silt and sand (GP -GM)
The recommended design infiltration rates in Table 4 are based on a minimum factor of safety of 2.0. The
designer should evaluate if a high factor of safety is warranted considering consequence of failure, facility
geometry, the use of facility outlet/overflow structures, influent control to reduce siltation and bio-buildup,
long-term maintenance considerations, or other factors.
Based on the results, the cementation of the soils has a significant effect on the infiltration rate of the site
soils. If the stormwater facilities are designed assuming no cementation is presentation, we recommend
that a representative of our firm observe the bottom of the infiltration facility to confirm the subgrade
conditions and determine if additional excavation is necessary.
Additionally, the design rates assume at least 3 feet of separation between groundwater and the bottom of
the facility. If closer separation is used, groundwater mounding may occur reducing the infiltration rates.
Groundwater was encountered at depths of 6 to 8 feet bgs at the time of exploration.
Earthwork
Excavation Considerations
Based on the subsurface soil conditions encountered in the test pits, we expect soil at the site may be
excavated using conventional construction equipment. The test pits were backfilled with the excavated soils
and tamped in place with the excavator bucket. No measurable compactive effort was completed in the
test pit backfill and the Contractor should make provisions to over excavate and compact those areas.
Ideally, earthwork should be undertaken during extended periods of dry weather when the surficial soils
will be less susceptible to disturbance and provide better support for construction equipment. Dry weather
construction will help reduce earthwork costs. If earthwork will occur from October through May, we suggest
that a contingency be included in the project schedule and budget to account for increased earthwork
difficulties.
Trafficability on the site is not expected to be difficult during dry weather conditions, provided surface water
is adequately controlled from entering the site and if groundwater is controlled in excavations. However,
the native soils will be susceptible to disturbance from construction equipment during wet weather
GEOENGINEERS� April8, 2019 Page 12
File No. 23820-001-00
conditions or if water is not controlled adequately. Even in the summer months pumping and rutting of the
exposed native soils under equipment loads will occur.
Clearing and Site Preparation
Areas to be developed or graded should be cleared of surface and subsurface deleterious matter including
any vegetation and debris.
Subgrade Preparation
The exposed subgrade in structure and hardscape areas should be prepared as described in the
Foundation, Slab -on -Grade Floors, and Pavement sections above. We should evaluate the prepared
subgrade after site excavation is complete. Disturbed areas below slabs should be recompacted, if
possible, or removed and replaced with structural fill.
Excavation Considerations
The stability of open -cut slopes is a function of soil type, groundwater seepage, slope inclination, slope
height and nearby surface loads. The use of inadequately designed open cuts could impact the stability of
adjacent work areas, adjacent properties, existing utilities and could endanger personnel.
The contractor performing the work has the primary responsibility for protection of workers and adjacent
improvements. In our opinion, the contractor will be in the best position to observe subsurface conditions
continuously throughout the construction process and to respond to variable soil and groundwater
conditions. Therefore, the contractor should have the primary responsibility for deciding whether to use
open -cut slopes rather than some form of temporary excavation support, and for establishing the safe
inclination of the cut slope. Acceptable slope inclinations for utilities and ancillary excavations should be
determined during construction. Because of the diversity of construction techniques and available shoring
systems, the design of temporary cut slopes is most appropriately left to the contractor proposing to
complete the installation. Temporary excavations should be sloped or shored in accordance with local, state
and federal regulations, including current OSHA excavation and trench safety standards.
Based on our observations in the test pits we recommend a maximum temporary cut slope inclination of
1.5H:1V be used for planning purposes during design. For open cuts at the site, we recommend that:
■ No traffic, construction equipment, stockpiles or building supplies be allowed at the top of the cut
slopes within a distance of at least 5 feet from the top of the cut;
■ The cut slopes should be planned such that they do not encroach on a 1H:1V influence line projected
down from the edges of nearby or planned foundation elements;
■ Exposed soil along the slope be protected from surface erosion by using waterproof tarps or plastic
sheeting;
■ Construction activities be scheduled so that the length of time the temporary cut is left open is reduced
to the extent practicable;
■ Erosion control measures be implemented as appropriate such that runoff from the site is reduced to
the extent practicable;
■ Surface water be diverted away from the slope; and
GEOENGINEERS� April8, 2019 Page 13
File No. 23820-001-00
■ The general condition of the slopes be observed immediately after excavation and periodically by the
geotechnical engineer to observe adequate stability.
Water that enters the excavation must be collected and routed away from prepared subgrade areas. Some
sloughing and raveling of the cut slopes should be expected. Temporary covering, such as heavy plastic
sheeting with appropriate ballast, should be used to protect these slopes during periods of wet weather.
Surface water runoff from above cut slopes should be prevented from flowing over the slope face by using
berms, drainage ditches, swales or other appropriate methods.
Imported Fill Materials
Imported fill materials should be specified as described below:
■ Structural Fill used below foundations, floor slabs and pavement areas should consist of 6-inch-minus
aggregate meeting the requirements of ISPWC Section 801.
■ Capillary break material below floor slabs should consist of 2-inch (Type II) Crushed Aggregate meeting
the requirements of ISPWC Section 802.
■ Structural fill placed as crushed surfacing base course below pavements and sidewalks should meet
the requirements of 3/4-inch (Type 1) Crushed Aggregate meeting the requirements of ISPWC
Section 802.
■ Drainage material should consist of Drain Rock meeting the requirements of ISPWC Section 801.
Reuse of On -site Soils
The on -site soil can be reused as structural fill, provided the soil can be adequately compacted. The on -site
soils contain an appreciable amount of fines and might be difficult to achieve the required compaction. We
anticipate the on -site soils will likely require moisture -conditioning to within 3 percent of the optimum
moisture content in order to meet the required compaction criteria. We anticipate the onsite soils will not
be suitable for reuse during the wet season.
Fill Placement and Compaction Criteria
Structural fill should be mechanically compacted to a firm, non -yielding condition. Structural fill should be
placed in loose lifts not exceeding 12 inches in thickness, except as specified below. Each lift should be
conditioned to the proper moisture content and compacted to the specified density before placing
subsequent lifts. Structural fill should be compacted to the following criteria:
■ Structural fill placed in building areas (supporting foundations or slab -on -grade floors) and in pavement
and sidewalk areas (including utility trench backfill) should be compacted to at least 95 percent of the
MDD as determined by ASTM D 1557.
■ Structural fill placed inutility trenches should be compacted to 90 percent MDD (ASTM D 1557), except
for the upper 2 feet of the trench under pavements and sidewalks, which should be compacted to
95 percent of the MDD.
■ Structural fill placed more than 2 feet below finished subgrade in pavement and hardscape areas
should be compacted to at least 90 percent of MDD (ASTM D 1557). Structural fill placed within the
GEOENGINEERS� April8, 2019 Page 14
File No. 23820-001-00
upper 2 feet below finished subgrade in pavement and hardscape areas should be compacted to at
least 95 percent of MDD.
■ Non-structural fill, such as fill placed in landscaped areas, should be compacted to at least 85 percent
of the MDD. In areas intended for future development, a higher degree of compaction should be
considered to reduce the settlement potential of the fill soil.
We recommend that GeoEngineers be present to evaluate subgrade soil conditions in building and
pavement areas, and during placement of structural fill. We will evaluate the adequacy of the subgrade
soils and identify areas needing further work, perform in -place moisture -density tests in the fill to verify
compliance with the compaction specifications, and advise on any modifications to the procedures that
may be appropriate for the site conditions.
Utility Trenches
Trench excavation, pipe bedding, and trench backfilling should be completed using the general procedures
required by the City of Meridian or other suitable procedures specified by the project Civil Engineer.
Utility trench backfill should consist of Structural Fill and should be placed in lifts of 12 inches or less (loose
thickness) such that adequate compaction can be achieved throughout the lift. Each lift must be compacted
prior to placing the subsequent lift. Prior to compaction, the backfill should be moisture conditioned to
within 3 percent of the optimum moisture content, if necessary. The backfill should be compacted in
accordance with the criteria discussed above.
Erosion and Sediment Control
In our opinion, the erosion potential of the on -site soils is low to moderate. Construction activities including
stripping and grading will expose soils to the erosional effects of wind and water. The amount and potential
impacts of erosion are partly related to the time of year that construction actually occurs. Wet weather
construction will increase the amount and extent of erosion and potential sedimentation.
Erosion and sedimentation control measures may be implemented by using a combination of interceptor
swales, straw bale barriers, silt fences and straw mulch for temporary erosion protection of exposed soils.
All disturbed areas should be finish graded and seeded as soon as practicable to reduce the risk of erosion.
Erosion and sedimentation control measures should be installed and maintained in accordance with the
state and local requirements.
Weather Considerations
Soils exposed during construction will be susceptible to rutting and pumping under construction traffic
when wet. Soils that rut, pump or are otherwise disturbed are not suitable for support of foundations, floor
slabs, or pavements and should be removed and replaced with Structural Fill. Measures that could help
reduce disturbance of exposed soils include performing earthwork during warm, dry weather, the use of
light track -mounted equipment, and avoidance of heavy repeated traffic over a given area. We recommend
that:
■ The ground surface in and around the work area should be sloped so that surface water is directed
away from the work area. The ground surface should be graded such that areas of ponded water do
not develop. The contractor should take measures to prevent surface water from collecting in
GEOENGINEERS� April8, 2019 Page 15
File No. 23820-001-00
excavations and trenches. Measures should be implemented to remove surface water from the
work area.
■ Slopes with exposed soils should be covered with plastic sheeting or similar means.
■ The site soils should not be left uncompacted and exposed to moisture. Sealing the surficial soils by
rolling with a smooth -drum roller prior to periods of precipitation will reduce the extent to which these
soils become wet or unstable.
■ Construction traffic should be restricted to specific areas of the site, preferably areas that are surfaced
with materials not susceptible to wet weather disturbance.
■ Construction activities should be scheduled so the length of time that soils are left exposed to moisture
is reduced to the extent practicable.
■ Fill should not be placed on frozen subgrade soils, nor should frozen soils be placed and compacted at
the site.
Recommended Additional Geotechnical Services
GeoEngineers authorized scope of services includes reviewing the project plans and specifications when
complete to confirm that our design recommendations have been implemented as intended.
During construction, GeoEngineers should be contracted to evaluate the suitability of the foundation
subgrades, observe installation of subsurface drainage measures, evaluate backfill placement and
compaction, observe the condition of temporary cut slopes, and provide a summary letter of our
construction observation services. The purposes of GeoEngineers construction phase services are to
confirm that the subsurface conditions are consistent with those observed in the explorations and other
reasons described in Appendix C, Report Limitations and Guidelines for Use.
LIMITATIONS
We have prepared this report for Phoenix Commercial Construction who may distribute copies of this report
to authorized agents and regulatory agencies as may be required for the project.
Within the limitations of scope, schedule and budget, our services have been executed in accordance with
generally accepted practices in the field of geotechnical engineering in this area atthe time this report was
prepared. The conclusions, recommendations, and opinions presented in this report are based on our
professional knowledge, judgment and experience. No warranty or other conditions, express or implied,
should be understood.
Any electronic form, facsimile or hard copy of the original document (email, text, table and/or figure), if
provided, and any attachments should be considered a copy of the original document. The original
document is stored by GeoEngineers, Inc. and will serve as the official document of record.
Please refer to Appendix C for additional information pertaining to use of this report.
GEOENGINEERS� April8, 2019 Page 16
File No. 23820-001-00
REFERENCES
Applied Technology Council (ATC) Online Hazard Tool, accessed on March 18, 2018 from website:
htti)s://hazards.atcouncil.org/.
ASCE, 2010. SEI/ASCE 7-10, Minimum Design Loads for Buildings and Other Structures. American Society
of Civil Engineers.
Idaho Standards for Public Works Construction, 2017.
International Code Council, 2015, "International Building Code."
Othberg, K. L. 1994. "Geology and Geomorphology of the Boise Valley and Adjoining Areas, Western Snake
River Plain, Idaho, Idaho Geological Survey."
Othberg, K.L., and Stanford, L.R., 1992, Geologic Map of the Boise Valley and Adjoining Area, Western
Snake River Plain, Idaho, Idaho Geological Survey, Geologic Map Series, GM-18, Scale 1:1,00,000.
U.S. Geological Survey, 2006, Quaternary fault and fold database for the United States, accessed March
18, 2019, from USGS web site: https://earthquake.usgs.F-Iov/hazards/cifauIts/.
GEOENGINEER� April8, 2019 Page 17
File No. 23820-001-00
GWENGINEERS
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"v 1. The locations of all features shown are approximate.
K 2. This drawing is for information purposes. It is intended to assist in
showing features discussed in an attached document. GeoEngineers, Inc
n cannot guarantee the accuracy and content of electronic files. The master
i file is stored by GeoEngineers, Inc. and will serve as the official record of
this communication.
J
hData Source: Mapbox Open Street Map, 2016
Projection: NAD 1983 UTM Zone 11N
L
Vicinity Map
Proposed Ustick Multifamily Development
Meridian, Idaho
GEOENGINEERFigure 1
IN
N Ridge Haven Way
. , v Legend
Site Boundary
r' * • TIP-1 Test Pit by GeoEngineers, 2019
INF-1 Test Pit with Infiltration Test by GeoEngineers, 2019
----- I --------------- I
INF-2 I„ -!T -6 1
1 I 1
1 b I 1
1 ' 1
1 r 1
I
MTE
Ei
tTP-3 TP-5
v
u 4 4 t0
1 Notes:
1- The locations of all features shown are approximate-
2. This drawing is for information purposes- It Is intended to
assist In showing features discussed In an attached document.
GeoEngineers. Inc - cannot guarantee the accuracy and content
ofelectrmi filesThemaster file is armed by GeoEngineers,
Inc and will serve as the official record of this communication -
I Data Source_ Aerial from Google Earth Pro dated 7/18/2018.
Preliminary Plat of Summertown Subtllvision by CK Engineering
dated 10/30/2017-
1 I 1 M
7-71
� Projection ID State Plane, West Zone, NAD83, US Foot
ITP-2 " I N Ridgeburry Ave
1 IFCI�NF-i
e f
TP-1
E I _J 100 0 100
Feet
N Venable Ln
1 — - rr
Site Plan
Proposed Ustick Multifamily Development
Meridian, Idaho
GEOENGINEERS� Figure
GWENGINEERS
APPENDIX A
Field Explorations
APPENDIX A
FIELD EXPLORATIONS
Subsurface conditions were explored at the site by excavating eight test pits (TP-1 through TP-6, INF-1, and
INF-2). Excavating was completed by Syman Company using a Case 580 rubber --tire excavator on March 7,
2019.
The locations of the test pits were estimated by using tablet and smart phone applications with a reported
accuracy of ± 16 feet (the highest published resolution for the software). The location was then adjusted
based on field measurements to existing features on the site plan. Exploration locations and elevations
should be considered accurate to the degree implied by the method used. The approximate exploration
locations are shown in Figure 2, Site Plan.
The test pits were continuously monitored by a representative from our firm who examined and classified
the soils encountered, obtained representative soil samples, observed groundwater conditions and
prepared a detailed log of each test pit.
The soil encountered in the test pits were selectively sampled from the excavations to obtain representative
samples for laboratory testing. Grab Samples were collected and stored in containers to preserve natural
moisture content for laboratory testing. The disturbed samples were obtained with a hand trowel or shovel.
Soils encountered in the test pits were visually classified in general accordance with the classification
system described in, Key to Exploration Logs, Figure A-1. A key to the test pit log symbols is also presented
in Figure A-1. The logs of the test pits are presented in Figures A-2 through A-9. The test pit logs are based
on our interpretation of the field and laboratory data and indicate the various types of soil and groundwater
conditions encountered. The logs also indicate the depths at which the soil or their characteristics change.
The densities noted on the test logs are based on the observations in the test pits and judgment based on
the conditions encountered.
Observations of groundwater conditions were made during excavation by observing moisture content of the
samples and noting any groundwater seepage into the test pits. The groundwater conditions encountered
during excavation are presented in the test pit logs. Groundwater conditions observed during excavation
represent a short-term condition and may or may not be representative of the long-term groundwater
conditions at the site. Groundwater conditions observed during excavating should be considered
approximate.
GEOENGINEERS� Aprii8,2019 PageA-1
File No. 23820-001-00
SOIL CLASSIFICATION CHART
ADDITIONAL MATERIAL SYMBOLS
MAJOR DIVISIONS
SYMBOLS
TYPICAL
DESCRIPTIONS
GRAPH LETTER
c
GRAVEL
CLEAN GRAVELS
o o
G.w
WELL -GRADED GRAVELS, GRAVEL -
SAND MIXTURES
AND
GRAVELLY
SOILS
(LIFFE OR NO FINES)
o O
O o
D O O
GP
POORLY -GRADED GRAVELS,
GRAVEL - SAND MIXTURES
GRAVELS WITH
FINES
°
GM
SI LTY GRAVELS, GRAVEL -SAND -
SILT MIXTURES
COARSE
GRAINED
SOILS
MORE THAN 50%
OF COARSE
FRACTION RETAIN
ON NG_4SIEVE
(APPRECIABLEAMOUNT
OFHNES)
O
GC
CLAYEY GRAVELS, GRAVEL - SAND -
CLAY MIXTURES
CLEAN SANDS
Sw
WELL -GRADED SANDS, GRAVELLY
SANDS
MORE THAN 50%
SAND
-
SP
POORLY -GRADED SANDS, GRAVELLY
SAND
RETAINED ON
NO. 200SIEVE
AND
SANDY
(LITTLE OR NO FINES)
SOILS
SANDS WITH
SM
SILTY SANDS, SAND - SILT MIXTURES
MORE THAN 50%
OF COARSE
FINES
FRACTION PASSING
-
Jl�
SC
CLAYEY SANDS. SAND - CLAY
MIXTURES
ON NO. 4 SIEVE
(APPRECIABLE AMOUNT
OF FINES)
INORGANIC SILTS, ROCK FLOUR,
ML
CLAYEY SILTS WITH SLIGHT
PLASTICITY
INORGANIC CLAYS OF LOW TO
FINE
GRAINED
SILTS AND
CLAYS
LIQUID LIMIT
LESS THAN 50
CL
MEDIUM PLASTICITY, GRAVELLY
CLAYS, SANDY CLAYS, SILTY CLAYS,
LEAN CLAYS
OL
ORGANIC SILTS AND ORGANIC SILTY
CLAYS OF LOW PLASTICITY
SOILS
MORE THAN 50%
PASSING
MH
INORGANIC SILTS, MICACEOUS OR
DIATOMACEOUS SILTY SOILS
NO. 200 SIEVE
CH
INORGANIC CLAYS OF HIGH
PLASTICITY
SILTS AND
CLAYS
LIQUID LIMIT GREATER
THAN 50
OH
ORGANIC CLAYS AND SILTS OF
MEDIUM TO HIGH PLASTICITY
HIGHLY ORGANIC SOILS
PT
PEAT, HUMUS, SWAMP SOILS WITH
HIGH ORGANIC CONTENTS
NOTE: Multiple symbols are used to indicate borderline or dual soil classifications
Sampler Symbol Descriptions
ILI 2.4-inch I.D. split barrel
N Standard Penetration Test (SPT)
■
Shelby tube
®
Piston
F]
Direct -Push
mBulk
or grab
Continuous Coring
Blow count is recorded for driven samplers as the number of
blows required to advance sampler 12 inches (or distance noted)
See exploration log for hammer weight and drop.
"P" indicates sampler pushed using the weight of the drill rig.
"WOH" indicates sampler pushed using the weight of the
hammer.
SYMBOLS
TYPICAL
DESCRIPTIONS
GRAPH
LETTER
AC
Asphalt Concrete
CC
Cement Concrete
CR
Crushed Rock/
Quarry Spalls
J b J ))
SOD
Sod/Forest Duff
TS
Topsoil
Groundwater Contact
Measured groundwater level in exploration,
well, or piezometer
Measured free product in well or piezomete
Graphic Log Contact
Distinct contact between soil strata
/
Approximate contact between soil strata
Material Description Contact
Contact between geologic units
Contact between soil of the same geologic
unit
Laboratory / Field Tests
%F Percent fines
%G Percent gravel
AL
Atterberg limits
CA
Chemical analysis
CID
Laboratory compaction test
CS
Consolidation test
DD
Dry density
DS
Direct shear
HA
Hydrometer analysis
MC
Moisture content
MD
Moisture content and dry density
Mohs
Mohs hardness scale
OC
Organic content
PM
Permeability or hydraulic conductivity
PI
Plasticity index
PP
Pocket penetrometer
SA
Sieve analysis
TX
Triaxial compression
UC
Unconfined compression
VS
Vane shear
Sheen Classification
NS
No Visible Sheen
SS
Slight Sheen
MS
Moderate Sheen
HS
Heavy Sheen
NOTE: The reader must refer to the discussion in the report text and the logs of explorations for a proper understanding of subsurface conditions -
Descriptions on the logs apply only at the specific exploration locations and at the time the explorations were made-, they are not warranted to be
representative of subsurface conditions at other locations or times -
Key to Exploration Logs
GEOENGINEER� FigureA-1
Rev 06/2017
Date
Total
Logged By SJW
Excavator man
Sy
See "Remarks" section for groundwater observed
3�7/2019
Excavated
11
Depth (ft)
Checked By RMH
Equipment Case 580 extendahoe
See 'Remarks" section for caving observed
Surface Elevation (ft) Undetermined
Lasting QQ
2451692
Coordinate System ID State Plane West
Vertical Datum
Northing (Y)
717227
Horizontal Datum NAD83 (feet)
SAMPLE
o
MATERIAL
o
REMARKS
Cl)z
J
M
DESCRIPTION
L
Q�
c
C
U7 >=
H
2
O
20
-0
W
F0
Ts
6 inches topsoil
1
PP = 2.5 tsf
ML
Brown sift with sand (very stiff, moist)
1
--
------------------------
CL
Brown lean clay with sand (stiff, moist)
PP =1.5 tsf
2
2
25
AL (LL = 37, P1= 20)
AL
PIP =2.0tsf
3
PP = 2.5 tsf
O
0
GP -GM
Brown fine to coarse gravel with silt and sand (dense, moist)
4
O
0
5
O
0
3
O
O
6
O
O
O
O
7
O
O
0
0
Becomes wet
Rapid groundwater observed at 7 feet
$
O
o
0
O
Moderate caving observed from 8 to 11 feet
y
O
O
O
O
10
0
0
O
O
O
11
Notes_ See Figure A-1 for explanation of symbols.
The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 1/2 foot
Coordinates Data Source: Horizontal approximated based on hand-held GPS. Vertical approximated based on (undetermined)_
Log of Test Pit TP 1
Project: Ustick Multifamily Development
G EO E N G I N E E RJ
Project Location: Meridian, Idaho
///
Figure A-2
Project Number: 23820-001-00 Sheet 1 of 1
Date
Total
Logged By SJW
Excavator Syman
See "Remarks" section for groundwater observed
3/7/2019
Excavated
95
Depth (ft)
Checked By RMH
Equipment Case 580 extendahoe
See 'Remarks" section for caving observed
Surface Elevation (ft) Undetermined
Fasting QQ
2451742
Coordinate System ID State Plane West
Vertical Datum
Northing (Y)
716977
Horizontal Datum NAD83 (feet)
t-rOJeCL: USLICK IVIUIUTam iy UeVeiopmenL
G EO E N G I N E E RJ
Project Location: Meridian, Idaho
///
Figure A-3
Project Number: 23820-001-00 Sheet 1 of 1
Date
Total
Logged By SJW
Excavator Syman
See "Remarks" section for groundwater observed
3�7/2019
Excavated
11
Depth (ft)
Checked By RMH
Equipment Case 580 extendahoe
See 'Remarks" section for caving observed
Surface Elevation (ft) Undetermined
Lasting QQ
2451960
Coordinate System ID State Plane West
Vertical Datum
Northing (Y)
717088
Horizontal Datum NAD83 (feet)
SAMPLE
o
MATERIAL
o
REMARKS
Cl)z
J
M
DESCRIPTION
L
Q�
c
C
U7 >=
H
2
O
20
-0
W
F0
Ts
6inchestopsoil
i
PP =1.5 tsf
ML
Brown sift with sand (stiff to very stiff, moist)
1
PIP =2.5tsf
2
--
------------------------
CL
Brown lean clay with sand and occasional gravel (very stiff, moist)
2
27
77
PP=2.5tsf
%F
3
GC
Brown clayey fine to coarse gravel with sand (dense, moist)
3
Strongly cemented
11
is
SA
q
0
5
O
GPM
Brown fine to coarse gravel with silt, sand and occasional cobbles
0
O
(dense to very dense, moist)
6
O
4
O
O
0
Becomes wet
Rapid groundwater observed at6'/2feet
7
0
0
O
S
0
o
O
O
9
O
0
0
0
Severe caving observed from 9 to 11 feet
10
O
0
O
O
0
0
11
Notes_ See Figure A-1 for explanation of symbols.
The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 1/2 foot
Coordinates Data Source: Horizontal approximated based on hand-held GPS. Vertical approximated based on (undetermined)_
Log of Test Pit TP 3
Project: Ustick Multifamily Development
G EO E N G I N E E RJ
Project Location: Meridian, Idaho
///
Figure A-4
Project Number: 23820-001-00 Sheet 1 of 1
Date
Total
Logged By SJW
Excavator man
Sy
See "Remarks" section for groundwater observed
3�7/2019
Excavated
11
Depth (ft)
Checked By RMH
Equipment Case 580 extendahoe
See 'Remarks" section for caving observed
Surface Elevation (ft) Undetermined
Lasting QQ
2452194
Coordinate System ID State Plane West
Vertical Datum
Northing (Y)
716950
Horizontal Datum NAD83 (feet)
SAMPLE
o
MATERIAL
o
REMARKS
Cl)z
J
M
DESCRIPTION
L
Q�
c
C
U7 >=
H
2
O
20
-0
W
F0
Ts
6inchestopsoil
i
PP =1.0 tsf
ML
Brown sift with sand (medium stiff to stiff, moist)
1
PP =1.0 tsf
2—
PIP = 0.5 tsf
3
?
Slightly cemented
30
AL (LL = 30. PI = 7)
AL
PP =1.0 tsf
4
Strongly cemented
GC
Brown clayey fine to coarse gravel with sand (dense, moist)
5
0
6
0
0
GPGM
Light brown fine to coarse gravel with silt and sand (very dense, wet)
3
0
Moderate groundwater seepage observed at 61/2 fee
7
0
0
0
S
0
o
0
0
9
0
0
o
0
Moderate caving observed from 9 to 11 feet
10
0
0
0
0
0
0
11
Notes_ See Figure A-1 for explanation of symbols.
The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 1/2 foot
Coordinates Data Source: Horizontal approximated based on hand-held GPS. Vertical approximated based on (undetermined)_
Log of Test Pit TP-4
Project: Ustick Multifamily Development
G EO E N G I N E E RJ
Project Location: Meridian, Idaho
///
Figure A-5
Project Number: 23820-001-00 Sheet 1 of 1
Date Total
Logged By SJW
Excavator Syman
See "Remarks" section for groundwater observed
3/7/2019 10.5
Excavated Depth (ft)
Checked By RMH
Equipment Case 580 extendahoe
See 'Remarks" section for caving observed
Surface Elevation (ft) Undetermined
Lasting QQ
2451959
Coordinate System ID State Plane West
Vertical Datum
Northing (Y)
716768
Horizontal Datum NAD83 (feet)
SAMPLE
o
o
MATERIAL
REMARKS
Cl)z
J
M
DESCRIPTION
L
Q�
c
C
V) V)
H
M
00
o o
U
-0
L� U
W
Cl)FO-
C7
C7 U
1
Ts
5 inches topsoil
Brown sift with sand (stiff, moist)
ML
PP =1.5 tsf
CL
Brown sandy lean clay (very stiff, moist)
PP=2.Otsf
2
2
20
58
%F
GM
PP = 2.5 tsf
Brown silty fine to coarse gravel with sand (dense to very dense, moist)
3
3
9
17
SA
4
5
0
0
GP -GM
Brown fine to coarse gravel with silt and sand (verydense, wet)
6
0
0
Rapid groundwater seepage observed at6feet
7
0
0
0
0
8
0
0
0
0
Slightly cemented
9
0
0
0
0
Rapid caving observed at 9 to 11 feet
10
0
0
0
0
Notes: See Figure A-1 for explanation of symbols.
The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 1/2 foot
Coordinates Data Source: Horizontal approximated based on hand-held GPS. Vertical approximated based on (undetermined)_
Log of Test Pit TP 5
Project: Ustick Multifamily Development
G EO E N G I N E E RJ
Project Location: Meridian, Idaho
Figure A 6
��
V.Project
Number: 23820-001-00 Sheet 1 of 1
Date
Total
Logged By SJW
Excavator man
Sy
See "Remarks" section for groundwater observed
3�7/2019
Excavated
11
Depth (ft)
Checked By RMH
Equipment Case 580 extendahoe
See 'Remarks" section for caving observed
Surface Elevation (ft) Undetermined
Lasting QQ
2452180
Coordinate System ID State Plane West
Vertical Datum
Northing (Y)
716622
Horizontal Datum NAD83 (feet)
SAMPLE
o
MATERIAL
o
REMARKS
Cl)z
J
M
DESCRIPTION
L
Q�
c
N
C
N
H
�U
W
Cl)H
C7
C70
1
Ts
6inchestopsoil
PP=2.0tsf
ML
Brown sift with fine sand (stiff to very stiff, moist) (native)
1
--
CL
------------------------
Brown lean clay with fine sand (medium stiff to stiff, wet)
PP=1.0tsf
2
2
PIP =0.5tsf
3
PP=0.5tsf
GC
Brown clayey fine to coarse gravel with sand (dense to very dense,
moist)
g
18
38
%F
4
O
ol
0
O
GPGM
Brown fine to coarse gravel with silt, sand and cobbles (dense, wet)
6
0
O
Moderate groundwater seepage observed at 6 feet
4
O
7
O O
O
8
O
O
O
O
9
O
O
0
O
Severe caving observed from 9 to 11 feet
10
O
0
O
O
O
0
11
Notes: See Figure A-1 for explanation of symbols.
The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 1/2 foot
Coordinates Data Source: Horizontal approximated based on hand-held GPS. Vertical approximated based on (undetermined)_
Log of Test Pit TP 6
Project: Ustick Multifamily Development
G EO E N G I N E E RJ
Project Location: Meridian, Idaho
///
Figure A 7
Project Number: 23820-001-00 sheet 1 of 1
Date
Total
Logged By SJW
Excavator
See "Remarks" section for groundwater observed
Excavated 3/7/2019
Depth (ff) 9
Checked By RMH
Equipment Case 580 extendahoe
See 'Remarks" section for caving observed
Surface Elevation (ft) Undetermined
Lasting QQ
245168LL�
rdinate System ID State Plane West
Vertical Datum
Northing (Y)
716624
zontal Datum NAD83 (feet)
SAMPLE
o
MATERIAL
o
REMARKS
Cl)z
J
M
DESCRIPTION
L
Q�
c
C
U7 >=
H
CL
2
O
20
-0
W
F0
TS
8 inches topsoil
g
PP = 1.0 tsf
CL
Brown lean clay with sand (medium stiff to stiff, moist)
1
GC
tight brown clayey fine to coarse gravel with sand (dense, moist)
2
2
0
Strongly cemented
3
3
'.
9
11
Infiltration test completed at 3 feet
SPSM
tight brown fine to coarse sand with silt and gravel (dense, moist)
SA
4-
5-
6—
Becomes wet
Rapid groundwater seepage observed at 6 feet
7
Severe caving observed from 71/2 to 9 feet
8
9
Notes_ See Figure A-1 for explanation of symbols.
The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 1/2 foot
Coordinates Data Source: Horizontal approximated based on hand-held GPS. Vertical approximated based on (undetermined)_
Log of Test Pit INF-1
Project: Ustick Multifamily Development
G EO E N G I N E E RJ
Project Location: Meridian, Idaho
///
Figure A-8
Project Number: 23820-001-00 Sheet 1 of 1
Date
Total
Logged By SJW
Excavator
See "Remarks" section for groundwater observed
Excavated 3/7/2019
Depth (ff)
Checked By RMH
Equipment Case 580 extendahoe
See 'Remarks" section for caving observed
Surface Elevation (ft) Undetermined
Lasting QQ
245217LL�
rdinate System ID State Plane West
Vertical Datum
Northing (Y)
717410
zontal Datum NAD83 (feet)
SAMPLE
o
MATERIAL
o
REMARKS
Cl)z
J
M
DESCRIPTION
L
Q�
c
C
V) V)
H
M
00
o o
U
-0
L� U
W
Cl)FO-
C7
C7 U
1
Ts
6 inches topsoil
PP = 2.5 tsf
ML
Brown sift with fine sand (very stiff, moist)
1
CL
Brown lean clay with fine sand (very stiff, moist)
PIP =2.0tsf
2
2
PIP =2.5tsf
3
Strongly cemented
PIP =2.5tsf
4
0
0
GP -GM
Brown fine to coarse gravel with silt and sand (very dense, moist)
5
s
0
0
o
0
Strongly cemented from 5 to 10 feet
Pilot infiltration test com leted at 5 feet
p
6
0
0
0
0
�
0
o
0
0
$
0
o
0
0
Becomes wet
Rapid groundwater seepage observed at 8 feet
9
0
0
0
0
10
0
0
0
0
Moderate caving observed from 10 to 12 feet
11
0
0
0
0
0
12
Notes: See Figure A-1 for explanation of symbols.
The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 1/2 foot
Coordinates Data Source: Horizontal approximated based on hand-held GPS. Vertical approximated based on (undetermined)_
Log of Test Pit INFL2
Project: Ustick Multifamily Development
G EO E N G I N E E RJ
Project Location: Meridian, Idaho
///
Figure A 9
Project Number: 23820-001-00 Sheet 1 of 1
APPENDIX B
Laboratory Testing
APPENDIX B
LABORATORY TESTING
General
Soil samples obtained from the test pits were transported to GeoEngineers' laboratory and evaluated to
confirm or modify field classifications, as well as to evaluate engineering properties of the soil. We
completed laboratory testing on the soil samples to determine the moisture content, grain size
distribution, and corrosion testing. The tests were performed in general accordance with test methods of
ASTM International (ASTM) or other applicable procedures.
Moisture Content
Moisture content tests were completed in general accordance with ASTM D 2216 for representative
samples obtained from the test pits. The results of these tests are presented on the test pit logs in Figures
A-2 through A-9, at the respective sample depths.
Grain Size Distribution
The disturbed soil samples obtained from the test pits were tested in general accordance with ASTM D
422 to evaluate the grain size distribution. The results of the grain size analyses were plotted and
classified in general accordance with USCS and are presented in Figures B-1 and B-2.
Atterberg Limits
Atterberg limit tests were completed for two native soil samples. The tests were used to classify the soil as
well as to aid in evaluating index properties and consolidation characteristics of the fine-grained soil
deposits. The liquid limit and the plastic limit were obtained in general accordance with ASTM D 4318. The
results of the Atterberg limits are summarized in Figure B-3.
GEOENGINEERS� April8, 2019 Page B-1
File No. 23820-001-00
m
O
M
Z
Q-
Gi
C
(n
Z
CD77
`m
m
m_
>
U
O
M
y
0
(D
(D
CD
y
-7
O
3
(D(D
N
U.S. STANDARD SIEVE SIZE
X 1.5" 3/4" 3/8" #4 #10 #20 #40 #60 #100 #200
x
100
LU
cs
90
r
m
80
Z
Q 70
a
Z 60
LU
a 50
30
20
10
0
1000 100 10 1 0.1
GRAIN SIZE IN MILLIMETERS
0.01 0.001
GRAVEL SAND
COBBLES SILT OR CLAY
COARSE I FINE COARSE MEDIUM I FINE
Symbol
Boring Number
Depth
(feet)
Moisture
(%)
Soil Description
TP-2
1.5-2
22
Sandy lean clay (CL)
TP-3
3.5-4
11
Clayey fine to coarse gravel with sand (GC)
TP-5
3-3.5
9
Silty fine to coarse gravel with sand (GM)
Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they were
performed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes.
The grain size analysis results were obtained in general accordance with ASTM D 6913.
m
O
M
Z
Q-
Gi
C
(n
Z
CD77
`m
m
m_
>
U
O
M
y
0
(D
(D
CD
y
-17
O
3
fD
O
N
U.S. STANDARD SIEVE SIZE
X 1.5" 3/4" 3/8" #4 #10 #20 #40 #60 #100 #200
x
100
LU
cs
90
r
m
80
Z
Q 70
a
Z 60
LU
a 50
C[iA
30
20
10
0
1000 100 10 1 0.1
GRAIN SIZE IN MILLIMETERS
0.01 0.001
GRAVEL SAND
COBBLES SILT OR CLAY
COARSE I FINE COARSE MEDIUM I FINE
Symbol
Boring Number
Depth
(feet)
Moisture
N
Soil Description
O
INF-1
3-3.5
9
Fine to coarse sand with silt and gravel (SP-SM)
❑
INF-2
5-5.5
8
Fine to coarse gravel with silt and sand (GP -GM)
Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they were
performed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes.
The grain size analysis results were obtained in general accordance with ASTM D 6913.
23820-01-00 Date Exported: 03/19/2019
4'71l
w 40
0
z
v 30
W
J
d
20
Fail
0
0
PLASTICITY CHART
CH
000�
H
P'
OH or
MH
L or
00
MIL or
CL-M
10 20 30 40 50 60 70 80 90 100 110
LIQUID LIMIT
Moisture
Liquid
Plasticity
Boring
Depth
Content
Limit
Index
Symbol
Number
(feet)
(%)
(%)
(%)
Soil Description
Q
TP-1
2-2.5
25
37
20
Lean clay with sand (CL)
❑
TP-4
3-3.5
30
30
7
Silt with sand (ML)
Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable
only to the specific sample on which they were performed, and should not be interpreted as representative of any other
samples obtained at other times, depths or locations, or generated by separate operations or processes.
The liquid limit and plasticity index were obtained in general accordance with ASTM D 4318.
Atterberg Limits Test Results
Proposed Ustick Multifamily Development
Meridian, Idaho
GEOENGINEERS� Figure B-3
APPENDIX C
Report Limitations and Guidelines for Use
APPENDIX C
REPORT LIMITATIONS AND GUIDELINES FOR USE'
This appendix provides information to help you manage your risks with respect to the use of this report.
Read These Provisions Closely
It is important to recognize that the geoscience practices (geotechnical engineering, geology and
environmental science) rely on professional judgment and opinion to a greater extent than other
engineering and natural science disciplines, where more precise and/or readily observable data may exist.
To help clients better understand how this difference pertains to our services, GeoEngineers includes the
following explanatory "limitations" provisions in its reports. Please confer with GeoEngineers if you need to
know more how these "Report Limitations and Guidelines for Use" apply to your project or site.
Geotechnical Services are Performed for Specific Purposes, Persons and Projects
This report has been prepared for Phoenix Commercial Construction and forthe proposed Ustick Multifamily
Development located at 745 Ustick Road in Meridian, Idaho. The information contained herein is not
applicable to other sites or projects.
GeoEngineers structures its services to meet the specific needs of its clients. No party other than the party
to whom this report is addressed may rely on the product of our services unless we agree to such reliance
in advance and in writing. Within the limitations of the agreed scope of services for the Project, and its
schedule and budget, our services have been executed in accordance with our Agreement with Phoenix
Commercial Construction dated February 8, 2019 and executed on February 20, 2019 and generally
accepted geotechnical practices in this area at the time this report was prepared. We do not authorize, and
will not be responsible for, the use of this report for any purposes or projects other than those identified in
the report.
A Geotechnical Engineering or Geologic Report is based on a Unique Set of Project -Specific
Factors
This report has been prepared for proposed Ustick Multifamily Development located at 745 Ustick Road in
Meridian, Idaho. GeoEngineers considered a number of unique, project -specific factors when establishing
the scope of services for this project and report. Unless GeoEngineers specifically indicates otherwise, it is
important not to rely on this report if it was:
■ not prepared for you,
■ not prepared for your project,
■ not prepared for the specific site explored, or
■ completed before important project changes were made.
For example, changes that can affect the applicability of this report include those that affect:
■ the function of the proposed structure;
1 Developed based on material provided by GBA, GeoProfessional Business Association, www.geoprofessional.org.
GEOENGINEERS� April8,2019 PageC-1
File No. 23820-001-00
■ elevation, configuration, location, orientation or weight of the proposed structure;
■ composition of the design team; or
■ project ownership.
If changes occur after the date of this report, GeoEngineers cannot be responsible for any consequences
of such changes in relation to this report unless we have been given the opportunity to review our
interpretations and recommendations. Based on that review, we can provide written modifications or
confirmation, as appropriate.
Environmental Concerns are Not Covered
Unless environmental services were specifically included in our scope of services, this report does not
provide any environmental findings, conclusions, or recommendations, including but not limited to, the
likelihood of encountering underground storage tanks or regulated contaminants.
Subsurface Conditions Can Change
This geotechnical or geologic report is based on conditions that existed at the time the study was performed.
The findings and conclusions of this report may be affected by the passage of time, by man-made events
such as construction on or adjacent to the site, new information or technology that becomes available
subsequent to the report date, or by natural events such as floods, earthquakes, slope instability or
groundwater fluctuations. If more than a few months have passed since issuance of our report or work
product, or if any of the described events may have occurred, please contact GeoEngineers before applying
this report for its intended purpose so that we may evaluate whether changed conditions affect the
continued reliability or applicability of our conclusions and recommendations.
Geotechnical and Geologic Findings are Professional Opinions
Our interpretations of subsurface conditions are based on field observations from widely spaced sampling
locations at the site. Site exploration identifies the specific subsurface conditions only at those points where
subsurface tests are conducted or samples are taken. GeoEngineers reviewed field and laboratory data
and then applied its professional judgment to render an informed opinion about subsurface conditions at
other locations. Actual subsurface conditions may differ, sometimes significantly, from the opinions
presented in this report. Our report, conclusions and interpretations are not a warranty of the actual
subsurface conditions.
Geotechnical Engineering Report Recommendations are Not Final
We have developed the following recommendations based on data gathered from subsurface
investigation(s). These investigations sample just a small percentage of a site to create a snapshot of the
subsurface conditions elsewhere on the site. Such sampling on its own cannot provide a complete and
accurate view of subsurface conditions for the entire site. Therefore, the recommendations included in this
report are preliminary and should not be considered final. GeoEngineers' recommendations can be
finalized only by observing actual subsurface conditions revealed during construction. GeoEngineers
cannot assume responsibility or liability for the recommendations in this report if we do not perform
construction observation.
GEOENGINEERS� April 8,2019 PageC-2
File No. 23820-001-00
We recommend that you allow sufficient monitoring, testing and consultation during construction by
GeoEngineers to confirm that the conditions encountered are consistent with those indicated by the
explorations, to provide recommendations for design changes if the conditions revealed during the work
differ from those anticipated, and to evaluate whether earthwork activities are completed in accordance
with our recommendations. Retaining GeoEngineers for construction observation forthis project isthe most
effective means of managing the risks associated with unanticipated conditions. If another party performs
field observation and confirms our expectations, the other party must take full responsibility for both the
observations and recommendations. Please note, however, that another party would lack our project -
specific knowledge and resources.
A Geotechnical Engineering or Geologic Report Could Be Subject to Misinterpretation
Misinterpretation of this report by members of the design team or by contractors can result in costly
problems. GeoEngineers can help reduce the risks of misinterpretation by conferring with appropriate
members of the design team after submitting the report, reviewing pertinent elements of the design team's
plans and specifications, participating in pre -bid and preconstruction conferences, and providing
construction observation.
Do Not Redraw the Exploration Logs
Geotechnical engineers and geologists prepare final boring and testing logs based upon their interpretation
of field logs and laboratory data. The logs included in a geotechnical engineering or geologic report should
never be redrawn for inclusion in architectural or other design drawings. Photographic or electronic
reproduction is acceptable, but separating logs from the report can create a risk of misinterpretation.
Give Contractors a Complete Report and Guidance
To help reduce the risk of problems associated with unanticipated subsurface conditions, GeoEngineers
recommends giving contractors the complete geotechnical engineering or geologic report, including these
"Report Limitations and Guidelines for Use." When providing the report, you should preface it with a clearly
written letter of transmittal that:
■ advises contractors that the report was not prepared for purposes of bid development and that its
accuracy is limited; and
■ encourages contractors to conduct additional study to obtain the specific types of information they
need or prefer.
Contractors are Responsible for Site Safety on Their Own Construction Projects
Our geotechnical recommendations are not intended to direct the contractor's procedures, methods,
schedule or management of the work site. The contractor is solely responsible for job site safety and for
managing construction operations to minimize risks to on -site personnel and adjacent properties.
Biological Pollutants
GeoEngineers' Scope of Work specifically excludes the investigation, detection, prevention or assessment
of the presence of Biological Pollutants. Accordingly, this report does not include any interpretations,
recommendations, findings or conclusions regarding the detecting, assessing, preventing or abating of
Biological Pollutants, and no conclusions or inferences should be drawn regarding Biological Pollutants as
GEOENGINEERS� April 8,2019 PageC-3
File No. 23820-001-00
they may relate to this project. The term "Biological Pollutants" includes, but is not limited to, molds, fungi,
spores, bacteria and viruses, and/or any of their byproducts.
A Client that desires these specialized services is advised to obtain them from a consultant who offers
services in this specialized field.
Information Provided by Others
GeoEngineers has relied upon certain data or information provided or compiled by others in the
performance of our services. Although we use sources that we reasonably believe to be trustworthy,
GeoEngineers cannot warrant or guarantee the accuracy or completeness of information provided or
compiled by others.
GEOENGINEER� April 8,2019 PageC-4
File No. 23820-001-00
GMENGINEERS