HomeMy WebLinkAboutAppendix D Geologic and Geotechnical Engineering Investigation Report6634 Valjean Avenue, Van Nuys, California 91406 Phone: (818) 785-2158 Fax: (818) 785-1548
MDN 23013A
GEOLOGIC AND GEOTECHNICAL ENGINEERING INVESTIGATION REPORT,
PROPOSED SFD RESIDENTIAL DEVELOPMENT,
North Corner of Chase Road & Aria Lane,
Fontana, California
for Ridge Crest Real Estate, LLC July 19, 2022 W.O. 7726 (Revised July 28, 2022)
6634 Valjean Avenue, Van Nuys, California 91406 Phone: (818) 785-2158 Fax: (818) 785-1548
MDN 23013A
July 19, 2022 W.O. 7726
(Revised July 28, 2022)
RIDGE CREST REAL ESTATE, LLC
353 E. Angeleno Avenue A, Burbank, California 91502
Attention: Mr. Timothy Sales
Subject: Geologic and Geotechnical Engineering Investigation
Report, Proposed SFD Residential Development, North
Corner of Chase Road & Aria Lane, Fontana, California
As requested, GeoSoils Consultants, Inc. (GSC) has performed a geologic and geotechnical
engineering investigation on the subject tract. The purpose of this investigation is to provide
geologic and geotechnical engineering recommendations for site grading and foundations. The
report presents the results of our research, subsurface exploration, laboratory testing, site
reconnaissance, and provides geotechnical engineering recommendations for site grading.
Grading of the site is considered feasible from a geologic and geotechnical engineering
prospective, provided the recommendations presented herein are incorporated into the design
and implemented during grading.
We appreciate this opportunity to be of service to you. If you have any questions regarding this
report, or if we may be of further assistance to you, please do not hesitate to contact us.
Very truly yours,
GEOSOILS CONSULTANTS, INC.
MAHAN PASDARPOUR RUDY F. RUBERTI
PE 90111 CEG 1708
cc: (1) Addressee
GeoSoils Consultants Inc.
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TABLE OF CONTENTS
1.0 INTRODUCTION .................................................................................................... 1
1.1 Site Description ................................................................................................................ 1
1.2 Proposed Development .................................................................................................... 1
1.3 Scope of Services ............................................................................................................. 2
1.4 Limitations ....................................................................................................................... 2
2.0 FIELD EXPLORATION ........................................................................................... 3
3.0 LABORATORY TESTING ....................................................................................... 3
3.1 Soil Classification ............................................................................................................ 3
3.2 In Situ Moisture Content and Dry Unit Weight ............................................................... 4
3.3 Grain Size Distribution..................................................................................................... 4
3.4 Expansive Soil .................................................................................................................. 4
3.5 Consolidation Test............................................................................................................ 4
3.6 Compaction Tests ............................................................................................................. 5
3.7 Chemical Tests ................................................................................................................. 5
3.8 R-Value ............................................................................................................................ 5
4.0 FINDINGS ............................................................................................................... 5
4.1 Geologic Environment ..................................................................................................... 5
4.1.1 Regional Geologic Setting ........................................................................................ 6
4.1.2 Local Geologic Setting ............................................................................................. 6
4.1.3 Earth Materials .......................................................................................................... 6
4.1.4 Groundwater ............................................................................................................. 6
4.2 Faulting And Seismicity ................................................................................................... 7
4.2.1 Earthquake Characterization: .................................................................................... 7
4.2.2 Earthquake Intensity: ................................................................................................ 8
4.2.3 2019 California Building Code (CBC) Seismic Design Criteria .............................. 8
4.3 Secondary Earthquake Effects ......................................................................................... 9
4.3.1 Ground Rupture ........................................................................................................ 9
4.3.2 Landsliding ............................................................................................................. 10
4.3.3 Seiches and Tsunamis ............................................................................................. 10
GeoSoils Consultants Inc.
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4.3.4 Dry Sand Settlement Analysis ................................................................................ 11
4.3.5 Liquefaction ............................................................................................................ 11
4.4 Hydrocollapse................................................................................................................. 12
5.0 CONCLUSIONS.................................................................................................... 12
6.0 RECOMMENDATIONS ......................................................................................... 12
6.1 Removals ........................................................................................................................ 12
6.2 Foundation Recommendations ....................................................................................... 13
6.2.1 Footings................................................................................................................... 13
6.2.2 Post-tensioned Mat Slab ......................................................................................... 15
6.2.3 Foundation General Recommendations .................................................................. 20
6.3 Interior Slabs .................................................................................................................. 21
6.4 Exterior Slabs ................................................................................................................. 22
6.5 Infiltration Testing.......................................................................................................... 23
6.6 Corrosion Characteristics of Soil ................................................................................... 24
6.7 Pavement Sections.......................................................................................................... 26
6.7.1 Asphalt Concrete ..................................................................................................... 26
6.7.2 Rigid Concrete Pavements ...................................................................................... 29
6.8 Grading ........................................................................................................................... 29
6.8.1 General .................................................................................................................... 29
6.8.2 Site Preparation ....................................................................................................... 30
6.8.3 Fill Placement ......................................................................................................... 31
6.8.4 Construction Considerations ................................................................................... 35
6.8.5 Earthwork Adjustment Factors ............................................................................... 35
6.8.6 Temporary Excavation ............................................................................................ 35
6.8.7 Excavation Observation .......................................................................................... 36
6.8.8 Utility Trenching and Backfill ................................................................................ 37
7.0 CLOSURE ............................................................................................................ 38
Enclosures
References
Plate 1, Site Plan
Appendix A, Field Procedures
GeoSoils Consultants Inc.
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Plates A-1 to A-7, Boring Logs
Appendix B, Laboratory Test Results
Plate EI-1, Expansion Index
Plates C-1 to C-7, Collapse and Swell Test Diagrams
Plates G-1 to G-10, Grain Size Test Diagrams
Plate MDD-1 to MDD-2, Maximum Dry Density Test
Plate RV-1 to RV-2, R-Value Test
Plate Ch-1, Chemical Test
Appendix C, Infiltration Test Results
cc: (1) Addressee
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1.0 INTRODUCTION
The purpose of this investigation is to provide geologic and geotechnical engineering data
and recommendations to aid in development of the subject site. The following sections
provide a summary of our subsurface exploration, laboratory testing, geologic and
geotechnical engineering conditions, and recommendations for site grading, fill placement,
and foundations.
This report has been prepared in accordance with generally accepted geotechnical
engineering practices in the City of Fontana and the time it was prepared. The report
presents a brief description of the site, the geotechnical engineering characteristics of the
area, the seismicity of the area, an engineering analysis of the site characteristics,
conclusions, and recommendations to develop the site.
Opinions presented in this report are based on an inspection of the site, geologic mapping,
a review of the regional geologic maps and seismic hazard reports, review of previous
consultant reports for the subject area, and our general knowledge of the geologic and soils
engineering conditions in the site area. The opinions presented have been arrived at
through the exercise of the generally understood standard of care for our profession and
standard of engineering practice for the City of Fontana, as we understand it.
1.1 Site Description
The subject site is located within the City of Fontana located at north corner of
Chase Road & Aria Lane (Figure 1). All the surrounding roads are paved and there
are similar residential development to the north, east and west sides. The site is
currently vacant and on the south side is partially surrounded by chase road and
partially by similar residential developments. The site is currently covered with
cobbles and low grasses.
SITE
SITE LOCATION MAP
NORTH CORNER OF CHASE ROAD & ARIA LANE
FONTANA, CALIFORNIA
RIDGECREST REAL ESTATE, LLC.GEOTECHNICAL GEOLOGIC ENVIRONMENTAL
GeoSoils Consultants Inc.GSC DATE:
W.O. NO.:
FIGURE 17726
7/2022
MDN 23013A
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(Revised July 28, 2022)
MDN 23013A
1.2 Proposed Development
Proposed development of the site will consist of construction of a residential complex
which includes 50 maximum two-story units, backbone streets, and parking lots.
Grading will include removing and recompacting unsuitable soil and establishing
design grades. The site plan is included as Plate 1.
1.3 Scope of Services
Our scope of services included the following:
• Site reconnaissance.
• Review of regional geologic maps, seismic hazard reports.
• Excavated, sampled, and logged 7 hollow stem auger borings to the depth of 30
feet at the locations shown on Plate 1, Site Plan.
• Laboratory testing.
• Infiltration Testing
• Engineering analyses.
• Preparation of this report.
1.4 Limitations
The findings and recommendations of this report were prepared in accordance with
generally accepted professional geotechnical engineering principles and practice for
the City of Fontana at this time. We make no other warranty, either express or
implied. The conclusions and recommendations contained in this report are based
on-site conditions disclosed in our site inspection and the referenced reports.
However, soil/rock conditions can vary significantly between borings and test pits;
therefore, further refinements of our recommendations contained herein may be
necessary due to changes in the building plans or what is encountered during site
grading.
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The recommendations provided in this report are applicable for preliminary
development planning for the referenced tract provided that surface water will be
kept from infiltrating into the subgrade adjacent to the house foundation systems.
This may include, but not be limited to rainwater, roof water, landscape water and/or
leaky plumbing. The lots are to be fine graded at the completion of construction to
include positive drainage away from the structure and roof water will be collected via
gutters, downspouts, and transported to the street in buried drainpipes. Home
buyers should be cautioned against constructing open draining planters adjacent to
the houses or obstructing the yard drainage in any way.
Since our investigation was based on the site conditions observed and engineering
analyses, the conclusions and recommendations contained herein are professional
opinions. Further, these opinions have been derived in accordance with standard
engineering practices, and no warranty is expressed or implied.
2.0 FIELD EXPLORATION
Nine hollow stem auger borings to the maximum depth of 50 feet, were excavated on the
site at the locations shown on Plate 1. Except Borings B-8 and B-9 that were drilled for
infiltration testing only, Soil samples were obtained from the rest of Borings with a California
ring sampler and SPT sampler. The hollow stem auger borings used the standard 140 lb.
hammer with a 30-inch drop.
A representative from our firm continuously observed the borings, logged the subsurface
conditions, and collected representative soil samples. All samples were stored in watertight
containers and later transported to our laboratory for further visual examination and testing,
as deemed necessary. After the test pits and boring were completed, the test pits and
boring were backfilled with soil cuttings.
The enclosed Boring Logs (Plates A-1 to A-7) describes the vertical sequence of soils and
materials encountered in the borings, based primarily on our field classifications and
supported by our subsequent laboratory examination and testing.
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3.0 LABORATORY TESTING 3.1 Soil Classification
Soil materials encountered within the property were classified and described in
accordance with the Unified Soil Classification System and in general accordance
with the current version of Test Method ASTM D 2488. The assigned group symbols
are presented in the exploration logs, Appendix A.
3.2 In Situ Moisture Content and Dry Unit Weight
In-place moisture content and dry unit weight of selected, relatively undisturbed ring
soil samples were determined in accordance with the current version of the Test
Method ASTM D 2435 and Test Method ASTM D2216, respectively. Once the dry
unit weights had been determined, in-place densities of underlying soil profile were
estimated. In those cases where ring samples were obtained, the moisture content
and dry unit weights are presented on Boring Log, Appendix A.
3.3 Grain Size Distribution
A grain size analysis was performed on a selected bulk sample of onsite soils in
accordance with the current versions of Test Method ASTM-D6913. The test result is
graphically presented on Plate G-1 through G-7.
3.4 Expansive Soil
Expansion index testing was performed on selected bulk samples of the on-site soils
in accordance with the current version of Test Method ASTM D4829-07. The test
results are presented in Plate EI-1. Additional testing will be performed at the
completion of grading. The test results indicate an expansion index of 5 and 12 (very
low range).
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3.5 Consolidation Test
Consolidation tests were performed on the selected ring samples. This test was
performed in general accordance with Test Method ASTM D 2435-04. The samples
were inundated at an approximate load of one ton per square foot to monitor the
hydro-consolidation. Results of the consolidation are presented on Plates C-1 to
C-7.
3.6 Compaction Tests
Two compaction tests were performed to determine to moisture density relationships
of the typical surficial soils encountered on the site. The laboratory standard used
was in accordance with ASTM Test Designation D-1557-12.
TABLE 1 COMPACTION TEST RESULTS
Sample Description Maximum Dry Density (pcf) Optimum Moisture Content (%)
B-3 @ 0-5’ Brown silty very fine to coarse SAND 132.5 8.5
B-4 @ 0-5’ Brown Silty Very Fine to Coarse SAND
128.5 9.0
3.7 Chemical Tests
Samples of the near surface soil were sent to an independent outside laboratory for
chemical analyses to determine the chemical content of soil. The results are
included in Appendix B and discussed in “corrosion section”.
3.8 R-Value
Two R-value tests were performed per Caltrans standard on the surficial samples
and the result is in Appendix B. We came to 78 and 80 R-value for design purposes.
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4.0 FINDINGS 4.1 Geologic Environment
Geologic conditions on the subject site were determined through research, field
mapping, and subsurface exploration, and the results were superimposed on the
Site Plan, Plate 1. During grading, a geologist should be present to confirm the
geologic conditions encountered on the site are consistent with those presented
herein. The following sections present our findings concerning subsurface and
groundwater conditions.
4.1.1 Regional Geologic Setting
The subject site is located within the northern part Peninsular Ranges
Geomorphic Province of California. The Peninsular Ranges extend into lower
California and are bound on the east by the Colorado Desert. The Los
Angeles Basin and the island group (Santa Catalina, Santa Barbara, and the
distinctly terraced San Clemente and San Nicolas islands), together with the
surrounding continental shelf (cut by deep submarine fault troughs), are
included in this province. A series of ranges is separated by northwest
trending valleys, subparallel to faults branching from the San Andreas Fault.
The trend of topography is similar to the Coast Ranges, but the geology is
more like the Sierra Nevada, with granitic rock intruding the older
metamorphic rocks (see Figure 2).
4.1.2 Local Geologic Setting
The subject site is located within an alluvial filled valley south of the San
Gabriel Mountains and north of the South San Jose Hills. Sediments filling
the valley were derived primarily from the San Gabriel Mountains.
GEOTECHNICAL GEOLOGIC ENVIRONMENTAL
GeoSoils Consultants Inc.GSC
DATE:
W.O. NO.:
REGIONAL GEOLOGIC MAP
NORTH CORNER OF CHASE ROAD & ARIA LANE
FONTANA, CALIFORNIA
RIDGECREST REAL ESTATE, LLC.
FIGURE 2
SITE
MDN 23013A
7/2022
7726
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4.1.3 Earth Materials
Alluvium (Qal)
Alluvium underlies the site and consists of brown to yellowish brown, silty
gravelly sand and sandy gravel that is dry to moist and dense.
4.1.4 Groundwater Groundwater was not encountered in any of the borings or test pits excavated
on the site. Perched groundwater conditions may exist within the alluvium
during wet periods of the year. Historic high groundwater levels are at depths
of at least 100 feet below the ground surface.
4.2 Faulting and Seismicity
The project site is not located within an Alquist-Priolo Earthquake Fault Zone and
there are no active faults on or adjacent to the property (Figure 3)1. Although there
are no faults on or adjacent to the property, there are faults near the site that can
cause moderate to intense ground shaking during the lifetime of the proposed
development. Therefore, earthquake resistant design is recommended.
The closest active fault to the site is the Sierra Madre fault zone, located
approximately 3.2 miles to the north. The Sierra Madre-Cucamonga fault zone
marks the southern margin of uplift of the San Gabriel Mountains, although the
Santa Susana fault extends the zone of south-vergent uplift west of these
mountains. Published slip rates vary widely along the fault zone. The best-
understood part of the fault is the easternmost section, the Cucamonga fault zone,
with excellent geomorphic expression, several trenches, and age control from
radiocarbon and soil stratigraphic studies. These studies have demonstrated
multiple Holocene events on several strands of the Cucamonga fault and a
minimum slip rate of 4.5 mm/yr. The slip rate on the Sierra Madre fault appears to
be considerably less than the Cucamonga fault, perhaps as low as 1 mm/yr or less.
GEOTECHNICAL GEOLOGIC ENVIRONMENTAL
GeoSoils Consultants Inc.GSC
DATE:
W.O. NO.:
SEISMIC HAZARD ZONE MAP
NORTH CORNER OF CHASE ROAD & ARIA LANE
FONTANA, CALIFORNIA
RIDGECREST REAL ESTATE, LLC.
FIGURE 3
SITE
7726
MDN 23013A
7/2022
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(Revised July 28, 2022)
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Studies on the San Fernando fault zone indicate a somewhat shorter recurrence
interval of perhaps as much as 4,000 yr. The Santa Susana fault is less well
understood, but has been inferred to have a slip rate greater than 5 mm/yr.
4.2.1 Earthquake Characterization:
Earthquakes are characterized by magnitude, which is a quantitative measure
of the earthquake strength, based on strain energy released during a seismic
event. The magnitude of an earthquake is constant for any given site and is
independent of the site in question.
4.2.2 Earthquake Intensity:
The intensity of an earthquake at a random site is not constant and is subject
to variations. The intensity is an indirect measurement of ground motion at a
particular site and is affected by the earthquake magnitude, the distance
between the site and the hypocenter (the location on the fault at depth where
the energy is released), and the geologic conditions between the site and the
hypocenter. Intensity, which is often measured by the Mercalli scale,
generally increases with increasing magnitude and decreases with increasing
distance from the hypocenter. Topography may also affect the intensity of an
earthquake from one site to another. Topographic effects such as steep
sided ridges or slopes may result in a higher intensity than sites located in
relatively flat-lying areas.
4.2.3 2019 California Building Code (CBC) Seismic Design Criteria
The 2019 CBC (California Building Code) seismic coefficient criteria are
provided in table 2 for structural design consideration. Under the Earthquake
Design Regulations of Chapter 16, Section 1613 of the CBC 2019, the
following coefficients apply for the proposed structures at the site2. Site Class
D should be used for the site. The following seismic data is presented for
preliminary design purposes. Ground motion parameters based on the
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Mapped Risk-Targeted Maximum Considered Earthquake (MCEr) were
determined and adhere to requirements discussed in ASCE 7-16 referenced
by the 2019 California Building Code. The parameters include 5% critical
damping for 0.2- and 1.0-second time periods. A summary of parameters is
provided in the table below for a Site Class D designation. These values may
only be used when the value of the seismic response coefficient Cs satisfies
equations 12.8-2, 12.8-3, or 12.8-4 of the ASCE 7-16 Standard.
TABLE 2 SEISMIC PARAMETERS
Description Value
Mapped Response (0.2 second), Ss 2.132
Mapped Spectral Response (1.0 second), S1 0.739
Short Period Site Coefficient, Fa 1.0
1-second Period Site Coefficient, Fv Null Adjusted Maximum Considered Earthquake Spectral Response (0.2 second), SMS 2.132
Adjusted Maximum Considered Earthquake Spectral Response (1.0 second), SM1 Null
5-percent Damped Design Spectral Response (0.2 second), SDS 1.421
5-percent Damped Design Spectral Response (1.0 second), SD1 Null
Maximum Considered Earthquake Geometric Mean Peak Ground Acceleration, PGAM 1.011 Site Coordinates: Latitude: 34.126010°, Longitude: -117.457176°
Conformance to the above criteria for seismic excitation does not constitute
any kind of guarantee or assurance that significant structural damage or
ground failure will not occur if a maximum level earthquake occurs. The
primary goal of seismic design is to protect life and not to avoid all damage,
since such design may be economically prohibitive. Following a major
earthquake, a building may be damaged beyond repair, yet not collapse.
4.3 Secondary Earthquake Effects
Ground shaking produced during an earthquake can result in a number of potentially
damaging phenomena classified as secondary earthquake effects. These
secondary effects include ground rupture, landslides, seiches and tsunamis,
seismically induced settlement, and liquefaction. Descriptions of each of these
phenomena and how it could potentially affect the proposed site are described as
follows:
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4.3.1 Ground Rupture
Ground rupture occurs when movement on a fault breaks the ground surface
and usually occurs along pre-existing fault traces where zones of weakness
already exist. The State has established Earthquake Fault Zones for the
purpose of mitigating the hazard of fault rupture by prohibiting the location of
most human occupancy structures across the traces of active faults.
Earthquake fault zones are regulatory zones that encompass surface traces
of active faults with a potential for future surface fault rupture. The site is not
located within a State established Earthquake Fault Zone and there are no
know active faults within the limits of the property (Figure 3); therefore, the
ground rupture hazard potential for the site is considered remote.
4.3.2 Landsliding
Landslides are slope failures that occur where the horizontal seismic forces
act to induce soil and/or bedrock failures. The most common affect is
reactivation or movement on a pre-existing landslide. Typically, existing
slides that are stable under static conditions (i.e., factor-of-safety above one)
become unstable and move during strong ground shaking. The site is flat and
not subject to landslides.
4.3.3 Seiches and Tsunamis
A seiche is the resonant oscillation of a body of water, typically a lake or
swimming pool caused by earthquake shaking (waves). The hazard exists
where water can be splashed out of the body of water and impact nearby
structures. No bodies of constant water are near the site, therefore, the
hazards associated with seiches are considered low.
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Tsunamis are seismic sea waves generated by undersea earthquakes or
landslides. When the ocean floor is offset or tilted during an earthquake, a set
of waves are generated similar to the concentric waves caused by an object
dropped in water.
Tsunamis can have wavelengths of up to 120 miles and travel as fast as 500
miles per hour across hundreds of miles of deep Ocean. Upon reaching
shallow coastal waters, the once two-foot high wave can become up to 50
feet in height causing great devastation to structures within reach. Tsunamis
can generate seiches as well. Due to the distance of the site relative to the
ocean, seiches and tsunamis are not considered a hazard to the site.
4.3.4 Dry Sand Settlement Analysis
Dry sand settlement can occur during moderate and large earthquakes when
loose, natural or fill sandy soils are densified and settle, often unevenly
across a site. In order for dry sand settlement to occur, the following four
factors are required: 1) Relatively dry soil or soil situated above the
groundwater table; 2) undrained loading (strong ground shaking), such as by
earthquake; 3) contractive soil response during shear loading, which is often
the case for a soil which is initially in a loose or uncompacted state; and 4)
susceptible soil type; such as clean, uniformly graded sands. Structures
situated above seismically densifying dry sandy soils may experience
settlement. Based on site exploration, this site has a low susceptibility to dry
sand settlement due to presence of cobbles and dense sandy layers to the
maximum depth explored of 50 feet.
4.3.5 Liquefaction
Liquefaction is a soil softening dynamic response, by which an increase in the
excess pore water pressure results in partial to full loss of soil shear strength
and post-liquefaction dissipation of this pore water pressure results in ground
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settlement shortly after the earthquake. In order for liquefaction to occur, the
following four factors are required: 1) saturated soil or soil situated below the
groundwater table; 2) undrained loading (strong ground shaking), such as by
earthquake; 3) contractive soil response during shear loading, which is often
the case for a soil which is initially in a loose or uncompacted state; and 4)
susceptible soil type; such as clean, uniformly graded sands, non-plastic silts,
or gravels. Based on site exploration, this site is not considered susceptible
to liquefaction since we have not encountered any perched ground water and
historic high ground water is deeper than 50 feet.
4.4 Hydrocollapse
Hydro-collapse is a condition where dry or moist soils undergo settlement upon
being wetted. In many cases no additional surcharge load is necessary to trigger the
Hydro-collapse. The potential for Hydro-collapse has been evaluated based upon
observations, the results of Swell/Collapse or Consolidation tests, and moisture-
density determinations for samples taken from the field. Department of Public Works,
Materials Engineering Division consider potentially collapsible soils as generally
having (a) low moisture contents (<8%), (b) low in-situ density(<108pcf), and (c)
subject to 2 or greater collapse potential.
A total of seven consolidation tests with hydro collapse were performed on samples
from upper 15 feet and are presented on the enclosed plates C-1 through C-7 in
Appendix B. All the samples have volume changes from -0.2 to -1.8%, which is
generally considered within a non-collapsible zone. Considering above values, we
concluded that, the on-site soil in-place poses a low potential for Hydro-collapse.
5.0 CONCLUSIONS The development of the subject site is considered feasible from a geologic and geotechnical
engineering viewpoint, provided that the recommendations presented in this report are
followed during grading.
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6.0 RECOMMENDATIONS
6.1 Removals
Removals shall extend a minimum of 5 (five) feet below existing ground surface or
proposed grades in building areas or 3 feet below the bottom of proposed
foundation, whichever is lower in elevation. Removals shall extend a minimum of
five feet beyond the building footprint or equal to the depth of removal, whichever is
greater. In the areas of streets and other miscellaneous structures, removals shall
extend a minimum of 3 (three) feet below existing ground surface. Deeper removals
may be required if soft or dry soil conditions are observed during grading or if
hardpan conditions are observed. We anticipate almost 10 to 20 percent of the on-
site soil comprise of more than 6 inches in diameter cobbles and should be off-
hauled and replaced by import fill materials. Preparation of areas to receive fill and
fill placement shall be performed as discussed under “Grading section”.
6.2 Foundation Recommendations
The following recommendations are provided for preliminary design purposes and
the final expansion index should be determined following grading. In our opinion,
conventional footings with slab-on-grade or post-tensioned interior slabs should be
used to support the proposed structures. As an alternative, a uniform post-tensioned
mat slab may be used to support the proposed structures.
All footings should meet current slope setback requirements. Foundations should be
designed for very low-expansive soil conditions. The proposed improvements should
be founded into compacted fill. Under no circumstances should foundations be cast
atop loose, soft, or slough, debris, existing artificial fill, topsoil, or surfaces covered
by standing water. Prior to placing concrete in a foundation excavation, an
inspection should be made by our representative to ensure that the foundation’s
subgrade is free of loose and disturbed soils and is embedded in the recommended
material. We offer the following site-specific recommendations and comments for
purposes of foundation design and construction.
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6.2.1 Footings
The proposed structures may be supported on footings with slab-on-ground
or post-tensioned interior slab. Exterior isolated pad footings may need to be
connected to adjacent footings via tie beams at the discretion of the project
structural engineer.
Subgrade Preparation
All conventional footings should be constructed on firm, unyielding certified
compacted fill. All compacted fill should be compacted to at least 90 percent
of the Modified Proctor maximum laboratory density, as determined by ASTM
D-1557-02 compaction method. Pre-moistening of all areas to receive
concrete is recommended. The moisture content of the subgrade soils should
be equal to or slightly greater than optimum moisture and verified by the
Geotechnical Engineer to a depth of 18 inches below adjacent grade within
24 hours of concrete placement. Footing’s subgrades shall be prepared in
accordance with the Grading section of this report.
Bearing Capacity
Continuous and isolated one- to two- story buildings footings should have a
width of at least 15 and 18 inches, respectively. New footings should extend
at least 12 inches below exterior grade, at least 6 inches below the bottom of
concrete slabs-on-grade, at least 6 inches below crawlspace grades,
whichever is deeper. Exterior isolated pad footings intended for support of
roof overhangs such as decks, patio covers and similar construction should
be a minimum of 24 inches square and founded at a minimum depth of 18
inches below the lowest adjacent final grade. Footings with at least above
minimum dimensions may be designed for a preliminary allowable bearing
pressure of 2,000 pounds per square foot (psf) for dead plus live loads, with a
one-third increase allowed when considering additional short-term wind or
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seismic loading. The allowable bearing value may be increased by 300
pounds per square foot per foot increase in depth or width to a maximum of
2500 psf. The weight of the footings may be neglected for design purposes.
All footings located adjacent to utility lines should be embedded below a 1:1
plane extending up from the bottom edge of the utility trench.
Settlement
The footings should be designed based on a low-expansive soils condition.
Thirty-year post-construction differential settlement due to static loads is not
expected to exceed about ¼-inch over 30 feet span for the proposed
improvements supported on footings, provided that the foundations are
designed and constructed as recommended.
Lateral Capacity
Lateral loads may be resisted by friction between the bottom of the footings
and the supporting subgrade, and by passive soil pressure acting against the
footings cast neat in foundation excavations or backfilled with properly
compacted structural fill. A coefficient of friction of 0.4 may be assumed for
design for footings supported on compacted fill. We recommend an
equivalent fluid pressure of 500 pounds per cubic foot for passive soil
resistance and not to exceed 2,000 pounds per cubic foot, where appropriate.
The upper foot of passive soil resistance should be neglected where soil
adjacent to the footing is not covered and protected by a concrete slab or
pavement. When combining passive pressure and frictional resistance, the
passive pressure component should be reduced by one-third. The above
values given for coefficient of friction and passive soil resistance are
allowable values with a factor of safety of 1.5 and the designed may choose
an appropriate factor of safety based on the loadings.
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General Structural Design
We recommend that foundations be reinforced with top and bottom steel, to
provide structural continuity and to permit spanning of local irregularities.
6.2.2 Post-tensioned Mat Slab
As a more conservative option, proposed structures be founded on post-
tensioned mat slab systems to mitigate the effect of expansive soil. The post-
tensioned mat slab should be at least 8 inches thick.
Subgrade Preparation
The subgrade soils below concrete flatwork areas to a minimum depth of 8
inches should be compacted to a minimum relative compaction of 90 percent
at or slightly above the optimum moisture content. Pre-saturation of the
subgrade below slabs will not be required; however, prior to placing concrete,
the subgrade below all dwelling and garage floor slab areas should be
thoroughly moistened to achieve a moisture content that is at least equal to or
no more than 6 percent greater than optimum moisture content to a minimum
depth of 8 inches below the bottoms of the slabs. Mat’s subgrades shall be
prepared in accordance with the Grading section of this report.
Bearing Capacity
An allowable average bearing capacity of 1,500 pounds per square foot may
be used for dead plus live loads, with a one-third increase allowed when
considering additional short-term wind or seismic loading. If requested, an
allowable localized bearing capacity under columns or walls can be provided
for a given loads layout.
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Settlement
The mat should be designed based on a low-expansive soils condition.
Thirty-year post-construction differential settlement due to static loads is not
expected to exceed about ¼-inch over 30 feet span for the proposed
improvements supported on mat foundation, provided that the foundations
are designed and constructed as recommended
Lateral Capacity
Lateral loads may be resisted by friction between the bottom of the footings
and the supporting subgrade, and by passive soil pressure acting against the
footings cast neat in foundation excavations or backfilled with properly
compacted structural fill. A coefficient of friction of 0.3 may be assumed for
design for footings supported on improved ground. We recommend an
equivalent fluid pressure of 500 pounds per cubic foot for passive soil
resistance and not to exceed 2,000 pounds per cubic foot, where appropriate.
The upper foot of passive soil resistance should be neglected where soil
adjacent to the footing is not covered and protected by a concrete slab or
pavement. When combining passive pressure and frictional resistance, the
passive pressure component should be reduced by one-third. The above
values given for coefficient of friction and passive soil resistance are
allowable values with a factor of safety of 1.5 and the designed may choose
an appropriate factor of safety based on the loadings.
General Structural Design
The structural design of a mat foundation supported on compacted fill must
evaluate the interaction between supporting soil and structure. Deepened
grade beams could be designed/constructed to improve mat stiffness, as
determined by the structural engineer.
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Selection of a modulus of subgrade reaction, Ks, is critical in the structural
design of a mat foundation. The basic value of Ks is defined as the unit
applied pressure divided by the settlement of a one square foot plate acting
on the subgrade surface. The values of Ks vary according to relative density,
consistency, and moisture content of the subgrade material. A modulus of
subgrade reaction of 150 pounds per cubic inch (pci) may be assumed for the
mat subgrade. This value is based on a 1-foot square bearing area and
should be scaled to account for mat foundation size and load effects.
Alternatively, based on the proposed preliminary buildings dimensions and
loads, a uniform modulus of subgrade reaction (Kv) of 30 pounds per cubic
inch (pci) may be assumed for the mat subgrade. A more accurate layout of
modulus of subgrade reaction (Kv) beneath each building can be provided if
requested by the structural engineer.
Post-Tensioned Design
Post-tensioned slabs should be designed in accordance with the
recommendations of Post-Tensioning Institute. Based on review of laboratory
data for the on-site materials, the on-site materials have a very low expansion
index. Deepened footings/edges around the slab perimeter must be used to
minimize non-uniform surface moisture migration (from an outside source)
beneath the slab. An edge depth of at least 8 inches should be considered.
The bottom of the deepened footing/edge should be designed to resist
tension, using cable or reinforcement per the Structural Engineer. Specific
recommendations for the design of Post Tension Institute methods are
presented below.
Post-tensioned slabs should have sufficient stiffness to resist excessive
bending due to non-uniform swell and shrinkage of subgrade soils. The
differential movement can occur at the corner, edge, or center of slab. The
potential for differential uplift can be evaluated using the design specifications
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of the Post-Tensioning Institute. The following table presents suggested
minimum coefficients to be used in the Post-Tensioning Institute design
method.
TABLE 3
SUGGESTED PT COEFFICIENTS
Description Value
Thornthwaite Moisture Index -20 in/year
Depth to Constant Soil Suction 9 feet Constant Soil Suction (pf) 3.8
The coefficients are considered minimums and may not be adequate to
represent worst case conditions such as adverse drainage, excess watering,
and/or improper landscaping and maintenance. The above parameters are
applicable provided structures have gutters and downspouts, yard drains, and
positive drainage is maintained away from structure perimeters. Also, the
values may not be adequate if the soils below the foundation become
saturated or dry such that shrinkage occurs. The parameters are provided
with the expectation that subgrade soils below the foundations are maintained
in a relatively uniform moisture condition. Responsible irrigation of
landscaping adjacent to the foundation must be practiced since over-irrigation
of landscaping can cause problems. Therefore, it is important that
information regarding drainage, site maintenance, settlements and effects of
expansive soils be passed on to future homeowners.
Based on the above parameters, the following preliminary values were
obtained from the Post Tension Institute Design manual. If a stiffer slab is
desired, higher values of ym may be warranted. We will revise the following
preliminary PT slab design values after rough grading in our final compaction
report upon some additional testing of the compacted fill.
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TABLE 4 PRELIMINARY PT SLAB DESIGN VALUES
Description Value
Soil Subgrade Expansion Index Very Low
em center lift 9 ft
em edge lift 4.7 ft
Ym center lift 0.25 in
Ym edge lift 0.45 in
Underlayment
In areas where dampness of concrete floor slabs would be undesirable, such
as habitable building interior, concrete slabs should be underlain by a
minimum 10 mil vapor barrier sandwiched between two (2) one-inch imported
sand layers. This vapor barrier shall be lapped and sealed (especially around
the utility perforations) adequately to provide a continuous waterproof barrier
under the entire slab. To reduce vapor transmission up through concrete
slabs, the vapor barrier should be high quality, UV-resistant conforming to the
requirements of ASTM E 1745 Class A, with a water vapor transmission rate
less than or equal to 0.01 perms (such as 15-mil thick “Stego Wrap Class A”).
The vapor barrier should be installed in accordance with ASTM E 1643. All
seams and penetrations of the vapor barrier should be sealed in accordance
with manufacturer’s recommendations.
Water:Cement Ratio
The permeability of concrete is affected significantly by the water:cement ratio
of the concrete mix, with lower water:cement ratios producing more damp-
resistant slabs and stronger concrete. Where moisture protection is important
and/or where the concrete will be placed directly on the vapor barrier, the
water:cement ratio should be 0.45 or less. To increase the workability of the
concrete, mid-range plasticizers can be added to the mix. Water should not
be added to the concrete mix unless the slump is less than specified and the
water:cement ratio will not exceed 0.45. Other steps that may be taken to
reduce moisture transmission through the concrete slabs-on-grade include
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moist curing for 5 to 7 days and allowing the slab to dry for a period of two
months or longer prior to placing floor coverings. Also, prior to installation of
the floor covering, it may be appropriate to test the slab moisture content for
adherence to the manufacturer’s requirements and to determine whether a
longer drying time is necessary.
6.2.3 Foundation General Recommendations
The above parameters are applicable provided structures have gutters and
downspouts and positive drainage is maintained away from structures.
Therefore, it is important that information regarding drainage and site
maintenance be passed on to future owners.
The above recommendations assume, and GeoSoils Consultants, Inc.
strongly recommends, that surface water will be kept from infiltrating into the
subgrade adjacent to the building foundation system. This may include, but
not be limited to rainwater, roof water, landscape water and/or leaky
plumbing. The lots are to be fine graded at the completion of construction to
include positive drainage away from the structure and roof water will be
collected via gutters, downspouts, and transported to the street in buried
drainpipes. Homebuyers should be cautioned against constructing open
draining planters adjacent to the houses or obstructing the yard drainage in
any way.
• Utility trenches beneath the slabs should be backfilled with compacted
native soil materials, free of rocks.
• Standard City of Fontana structural setback guidelines are applicable,
except where superseded by specific recommendations by the Project
Geologist and Geotechnical Engineer.
• Building or structure footings shall be set back a horizontal distance, x,
from the face of adjacent descending slope. The horizontal distance is
calculated as x=H/3, where H is the height of slope. The distance x should
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not be less than 5 feet nor more than 40 feet. The distance x may be
provided by deepening the footings.
6.3 Interior Slabs
General Recommendations
Interior concrete slabs may be used along with footings. Interior slabs subgrade
preparation, Underlayment, and water:cement ratio should be designed in
accordance with recommendations in mat slab section. A uniform modulus of
subgrade reaction (Kv) of 30 pounds per cubic inch (pci) may be assumed for slab
design. We note that a uniform 8-icnh PT slab poured monolithically with deepened
footings/grade beams would be considered a post-tension mat foundation with
stiffening grade beams as described before. Additional recommendation for
conventional and post-tensioned interior slab design is presented below.
Conventional Slab-on-ground Design
Conventional interior slabs should be at least 4 inches thick, and they should be
dwelled into the foundation system in habitable areas.
Post-Tensioned Slab Design
If Post-tensioned interior slabs with footings are selected, they should be designed in
accordance with post-tensioned recommendations in mat slab section. Post-
tensioned interior slabs should be at least 4 inches thick and can be poured
monolithically with the footings or as a separate section.
6.4 Exterior Slabs
Subgrade Preparation
To reduce the potential for distress to exterior concrete flatwork, the subgrade soils
below concrete flatwork areas to a minimum depth of 8 inches (or deeper, as either
prescribed elsewhere in this report or determined in the field) should be moisture
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conditioned to at least equal to, or slightly greater than, the optimum moisture
content and then compacted to a minimum relative compaction of 90 percent.
Where concrete public roads, concrete segments of roads and/or concrete access
driveways are proposed, the upper 6 inches of subgrade soil should be compacted
to a minimum 95 percent relative compaction.
As a further measure to reduce the potential for concrete flatwork cracking, subgrade
soils should be thoroughly moistened prior to placing concrete. The moisture
content of the soils should be at least the optimum moisture content to a minimum
depth of 8 inches into the subgrade. Flooding or ponding of the subgrade is not
considered feasible to achieve the above moisture conditions since this method
would likely require construction of numerous earth berms to contain the water.
Therefore, moisture conditioning should be achieved with sprinklers or a light spray
applied to the subgrade over a period of few to several days just prior to pouring
concrete. Pre-watering of the soils is intended to promote uniform curing of the
concrete, reduce the development of shrinkage cracks and reduce the potential for
differential expansion pressure on freshly poured flatwork. A representative of the
project geotechnical consultant should observe and verify the density and moisture
content of the soils, and the depth of moisture penetration prior to pouring concrete.
Drainage
Drainage from patios and other flatwork areas should be directed to local area drains
and/or graded earth swales designed to carry runoff water to the adjacent streets or
other approved drainage structures. The concrete flatwork should be sloped at a
minimum gradient of one percent, or as prescribed by project civil engineer or local
codes, away from building foundations, retaining walls, masonry garden walls and
slope areas.
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Thickened Edge
To improve performance, exterior slabs-on-grade may be constructed with a
thickened edge to improve edge stiffness and to reduce the potential for water
seepage under the edge of the slabs and into the underlying base and subgrade. In
our opinion, the thickened edges should be at least 8 inches wide and ideally should
extend at least 4 inches below the bottom of the underlying aggregate base layer.
6.5 Infiltration Testing
We have performed infiltration testing for the proposed LID dry well’s on the subject
site. Testing was performed in accordance with the San Bernardino County
Stormwater Program Manual titled “Technical Guideline Document for Water Quality
Management Plans” dated July 28, 2011.
Four dry well depths were proposed by the civil engineer of the record that are
percolating from 10 to 15, 20 to 30, 30 to 40 and 40 to 50 feet. The In-Situ Falling
Head Test method was used for determining the infiltration rate. Infiltration testing
was performed by Excavating eight-inch borings to the maximum depth of each
proposed dry well which was 15, 30, 40 and 50 feet. Perforated pipe was placed
within percolating depth and solid pipe was placed above it. The boring is labeled as
B-6, B-7 followed by B-8/P-1 and B-9/P-2 as shown on Plate 1. The infiltration test
results are provided as plates P-1 to P-4.
No groundwater was encountered during the excavations. Historical high
groundwater map from the Fontana Seismic Hazard Zone report notes the
groundwater to be more than 100 feet below the ground surface. The borings were
presoaked prior to the infiltration testing. The result is included in below table.
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TABLE 5 PERCOLATION TEST RESULTS
Test Location Percolation Depth (ft) Pre-Adjusted Rate (inch/hour) *
B-6 10-15 15.24
B-7 20-30 2.29
B-8/P-1 30-40 2.62
B-9/P-2 40-50 11.73
*Reduction factor should be applied by the Civil Engineer of The Record
It is our professional opinion that on-site infiltration will not be a hazard to the
potential development and the site is suitable for storm water infiltration. The
proposed infiltration rates were calculated in inches per hour and are without factor
of safety. Per our discussion with the civil engineer of the record, Mr. Anthony Ng
from United Civil Inc, it is our understanding that the civil engineer will apply an
appropriate factor of safety to these infiltration rates to calculate dry wells design
percolation rates.
6.6 Corrosion Characteristics of Soil
As a screening level study, limited chemical and electrical tests were performed on
samples considered representative of the onsite soils to identify potential corrosive
characteristics of these soils. The common indicators that are generally associated
with soil corrosivity, among other indicators, include water-soluble sulfate (a
measure of soil corrosivity on concrete), water-soluble chloride (a measure of soil
corrosivity on metals embedded in concrete), pH (a measure of soil acidity), and
minimum electrical resistivity (a measure of corrosivity on metals embedded in soils).
Test methodology and results are presented in Appendix B.
It should be noted that GeoSoils does not practice corrosion engineering; therefore,
the test results, opinion and engineering judgment provided herein should be
considered as general guidelines only. Additional analyses, and/or determination of
other indicators, would be warranted, especially, for cases where buried metallic
building materials (such as copper and cast or ductile iron pipes) in contact with site
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soils are planned for the project. In many cases, the project geotechnical engineer
may not be informed of these choices. Therefore, for conditions where such
elements are considered, we recommend that other, relevant project design
professionals (e.g., the architect, landscape architect, civil and/or structural engineer,
etc.) to be involved. We also recommend considering a qualified corrosion engineer
to conduct additional sampling and testing of near-surface soils during the final
stages of site grading to provide a complete assessment of soil corrosivity.
Recommendations to mitigate the detrimental effects of corrosive soils on buried
metallic and other building materials that may be exposed to corrosive soils should
be provided by the corrosion engineer as deemed appropriate.
In general, a soil’s water-soluble sulfate levels and pH relate to the potential for
concrete degradation; water-soluble chlorides in soils impact ferrous metals
embedded or encased in concrete, e.g., reinforcing steel; and electrical resistivity is
a measure of a soil’s corrosion potential to a variety of buried metals used in the
building industry, such as copper tubing and cast or ductile iron pipes. Table 6
below, presents test results with an interpretation of current code approach and
guidelines that are commonly used in building construction industry. The table
includes the code-related classifications of the soils as they relate to the various
tests, as well as a general recommendation for possible mitigation measures in view
of the potential adverse impact of corrosive soils on various components of the
proposed structures in direct contact with site soils. The guidelines provided herein
should be evaluated and confirmed, or modified, in their entirety by the project
structural engineer, corrosion engineer and/or the contractor responsible for
concrete placement for structural concrete used in the project.
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TABLE 6 SOIL CORROSIVITY SCREENING RESULTS
Test (Test Method Designation)
Test Location Test Results Classification General Recommendations
Soluble Sulfate (Cal 417) B-2 @ 0-5 13 ppm S0(1) - Not Applicable
Type II cement; minimum fc’ = 2,500 psi (2); no water/cement ratio restrictions.
pH (Cal 643) B-2 @ 0-5 5.5 Strongly Acid (3) Remove and replace soil around
the concrete; increase concrete cover thickness.
Soluble Chloride (Cal 422) B-2 @ 0-5 5.7 ppm C1 – Moderate (3) Residence: No special recommendations; fc’ should not be
less than 2,500 psi.
Resistivity (Cal 643) B-2 @ 0-5 12,400 ohm-cm Mildly Corrosive (4) Protective wrapping/coating of buried
pipes; corrosion resistant materials
Notes: 1. ACI 318-14, Section 19.3 2. fc’, 28-day unconfined compressive strength of concrete
3. ACI 318-14, Section 19.3 4. Pierre R. Roberge, “Handbook of Corrosion Engineering”
6.7 Pavement Sections
6.7.1 Asphalt Concrete
Based on the materials encountered in our borings and laboratory test
results, it is our opinion that an R-value of 78, is appropriate for design of the
parking area and drive isle pavements. Using estimated Traffic Indices for
various pavement loading conditions, we calculated the minimum pavement
section thicknesses presented in table below based on the pavement design
procedure described in Chapter 630 of the Caltrans Highway Design Manual.
We note that it is the civil engineer’s responsibility to choose an appropriate
traffic index for various pavement systems.
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TABLE 7 MINIMUM PAVEMENT SECTION THICKNESSES
Traffic Index Asphalt Thickness (in) Aggregate Thickness (in)
3.5 0.50 1.40
3.5 1.00 -0.10
4 0.50 1.80
4 1.00 0.50
4.5 0.50 2.30
4.5 1.00 1.10
4.5 1.50 -0.20
5 0.50 2.70
5 1.00 1.60
5 1.50 0.40
5.5 0.50 3.20
5.5 1.00 2.10
5.5 1.50 1.00
6 1.00 2.60
6 1.50 1.50
6 2.00 0.40
6.5 1.00 3.00
6.5 1.50 2.00
6.5 2.00 1.00
7 1.50 2.50
7 2.00 1.50
7 2.50 0.60
8 1.50 3.50
8 2.00 2.50
8 2.50 1.60
9 2.00 3.50
9 2.50 2.70
9 3.00 1.80
10 2.00 4.50
10 2.50 3.70
10 3.00 2.80
Subgrade soils immediately below the aggregate base, to a minimum depth
of 8 inches, should be compacted to a minimum relative compaction of 95
percent based on ASTM D1557. Final subgrade compaction should be
performed prior to placing base materials and after utility-trench backfills have
been compacted and tested.
Asphalt concrete and aggregate base should conform to and be placed in
accordance with the requirements of the Caltrans Standard Specifications,
latest edition, except that compaction of subgrades and aggregate base
material should be based on ASTM Test D1557. The base course should be
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compacted to 95 percent or more of the maximum dry density as evaluated
by ASTM D1557. The base materials should also meet the specifications for
Crushed Aggregate Base, Crushed Miscellaneous Base or Processed
Miscellaneous Base as defined in Section 200-2 of the current edition of the
Standard Specifications for Public Works Construction (Greenbook).
AC Paving:
Prime coat may be omitted if all of the following conditions are met:
1. The asphalt pavement layer is placed within two weeks of completion
of base and/or subbase course.
2. Traffic is not routed over completed base before paving.
3. Construction is completed during the dry season of May through
October.
4. The base is free of dirt and debris.
If construction is performed during the wet season of November through April,
prime coat may be omitted if no rain occurs between completion of base
course and paving, and the time between completion of base and paving is
reduced to three days, provided the base is free of dirt and debris. Where
prime coat has been omitted and rain occurs, traffic is routed over base
course, or paving is delayed, measures shall be taken to restore base course,
subbase course, and subgrade to conditions that will meet specifications as
directed by the geotechnical engineer.
We recommend that measures be taken to limit the amount of surface water
that seeps into the aggregate base and subgrade below vehicle pavements,
particularly where the pavements are adjacent to landscape areas. Seepage
of water into the pavement base material can soften the subgrade, thereby
increasing the amount of pavement maintenance that is required and
shortening the pavement service life. Deepened curbs extending 4-inches
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below the bottom of the aggregate base layer are generally effective in
limiting excessive water seepage below the edges of pavement and into the
subgrade. Other types of water cutoff devices or edge drains may also be
considered to maintain pavement service life.
6.7.2 Rigid Concrete Pavements
If the driveway will be constructed with Portland cement concrete (PCC), we
recommend the driveway pavement consist of at least 4 inches of PCC on at
least 6 inches of Class 2 aggregate base. Un-reinforced concrete for the 4-
inch-thick driveway pavement should have a 28-day compressive strength of
at least 3,500 psi. PCC pavements should be laterally constrained with curbs
or shoulders and sufficient control joints should be incorporated in the design
and construction to limit and control cracking.
The soil subgrade and aggregate base below the pavement section should be
prepared and compacted as recommended above. The use of a moisture
cut-off or thickened edge along the edges of the driveway would be desirable
in order to reduce water seepage below the edges of the driveway and into
the underlying aggregate base and subgrade, which can lead to premature
pavement distress.
6.8 Grading
Grading of the site will consist of a cut/fill operation to create level pads and
associated streets. The grading will involve the removing and recompacting of
existing near surface material. We offer the following recommendations and
construction considerations concerning earthwork grading at the site.
6.8.1 General
Monitoring: We recommend that all earthwork (i.e., clearing, site preparation,
fill placement, etc.) should be conducted with engineering control under
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observation and testing by the Geotechnical Engineer and in accordance with
the requirements within the Grading section of this report.
Job Site Safety: At all times, safety should have precedence over production
work. If an unsafe job condition is observed, it should be brought to the
attention of the grading contractor or the developer’s representative. Once
this condition is noted, it should be corrected as soon as possible, or work
related to the unsafe condition should be terminated.
The contractor for the project should realize that services provided by GSC
do not include supervision or direction of the actual work performed by the
contractor, his employees, or agents. GSC will use accepted geotechnical
engineering and testing procedures; however, our testing and observations
will not relieve the contractor of his primary responsibility to produce a
completed project conforming to the project plans and specifications.
Furthermore, our firm will not be responsible for job or site safety on this
project, as this is the responsibility of the contractor.
6.8.2 Site Preparation
Existing Structure Location: The General Contractor should locate all surface
and subsurface structures on the site or on the approved grading plan prior to
preparing the ground.
Existing Structure Removal: Any underground structures (e.g., septic tanks,
wells, pipelines, foundations, utilities, etc.) that have not been located prior to
grading should be removed or treated in a manner recommended by the
Geotechnical Engineer.
Clearing and Stripping: The construction areas should be cleared and
stripped of all vegetation, trees, bushes, sod, topsoil, artificial fill, debris,
asphalt, concrete, and other deleterious material prior to fill placement.
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Removals: Please refer to the Removals section of this report for specific
recommendations for removals.
Subgrade Preparation: We recommend that the subgrade for those areas
receiving any fill be prepared by scarifying the upper 12 inches and moisture
conditioning, as required to obtain at least optimum moisture, but not greater
than 120 percent of optimum. The scarified areas shall be compacted to at
least 90 percent of the maximum laboratory density, as determined by ASTM
D-1557-12 compaction method. All areas to receive fill should be observed
by the Geotechnical Engineer prior to fill placement.
Subgrade Verification and Compaction Testing: Regardless of material or
location, all fill material should be placed over properly compacted subgrades
in accordance with this section. The condition of all subgrades shall be
verified by the Geotechnical Engineer before fill placement or earthwork
grading begins. Earthwork monitoring and field density testing shall be
performed during grading to provide a basis for opinions concerning the
degree of soil compaction attained. The Contractor should be responsible for
notifying the Geotechnical Engineer when such areas are ready for
inspection. Inspection of the subgrade may also be required by the
controlling governmental agency within the respective jurisdictions. Density
tests should also be made on the prepared subgrade to receive fill, unless the
areas are underlain by dense alluvium, as required by the Geotechnical
Engineer.
6.8.3 Fill Placement
Laboratory Testing: Representative samples of materials to be utilized as
compacted fill should be analyzed in a laboratory to determine their physical
properties. If any material other than that previously tested is encountered
during grading, the appropriate analysis of this material should be conducted.
Page 33 July 19, 2022
W.O. 7726
(Revised July 28, 2022)
MDN 23013A
On-Site Fill Material: The on-site soils, in our opinion, are adequate for re-
use in controlled fills provided the soils do not contain any organic matter,
debris, and that over-sized rocks are buried in accordance with the
recommendations under Rock Fragments.
Rock Fragments: The alluvium on the site should be free of oversized rocks.
Any rock fragments over 6 inches should be kept below a depth of 5 feet
below proposed grade. Rocks greater than 6 inches in diameter should be
taken off site or placed in accordance with the recommendations of the
Geotechnical Engineer. Rocks greater than 6 inches in diameter shall be
kept out of all street areas to a depth below the deepest proposed utility line.
Rocks shall not be placed in concentrated pockets, shall be surrounded with
fine grained material, and the distribution of the rocks shall be supervised by
the Geotechnical Engineer. A sufficient amount of fine-grained material shall
be placed around the rocks to prevent nesting and to fill all void space. An
adequate amount of water will be required to force fines into any open voids.
Fill Placement: Approved on-site material shall be evenly placed, watered,
processed, and compacted in controlled horizontal layers not exceeding eight
inches in loose thickness, and each layer should be thoroughly compacted
with approved equipment. The fill should be placed and compacted in
horizontal layers, unless otherwise recommended by the Geotechnical
Engineer.
Compaction Criteria - Shallow Fills: For fills less than 40 feet in vertical
thickness, each layer shall be compacted to at least 90 percent of the
maximum laboratory density for material used as determined by ASTM D-
1557-12. The field density shall be determined by the ASTM D-1556-07
method or equivalent. Where moisture content of the fill or density testing
yields compaction results less than 90 percent, additional compaction effort
Page 34 July 19, 2022
W.O. 7726
(Revised July 28, 2022)
MDN 23013A
and/or moisture conditioning, as necessary, shall be performed, until the fill
material is in accordance with the requirements of the Geotechnical Engineer.
Fill Material - Moisture Content: All fill material placed must be moisture
conditioned, as required to obtain at least optimum moisture, but not greater
than 120 percent. If excessive moisture in the fill results in failing results or
an unacceptable “pumping” condition, then the fill should be allowed to dry
until the moisture content is within the necessary range to meet the required
compaction requirements or reworked until acceptable conditions are
obtained.
Keying and Benching: All fills should be keyed and benched through all
topsoil, slopewash, alluvium or colluvium or creep material into firm material
where the slope receiving fill is steeper than 5:1 (Horizontal: Vertical) or as
determined by Geotechnical Engineer. The standard acceptable bench
height is four feet into suitable material. The key for side hill fills should be a
minimum of 15 feet within compacted fill or firm materials, with a minimum toe
embankment of 2 feet into compacted fill, unless otherwise specified by the
Geotechnical Engineer.
Slope Face - Compaction Criteria: The Contractor should be required to
obtain a minimum relative compaction of 90 percent out to the finish slope
face of fill slopes. This may be achieved by either overbuilding the slope a
minimum of five feet, and cutting back to the compacted core, or by direct
compaction of the slope face with suitable equipment, or by any other
procedure which produces the required compaction. If the method of
achieving the required slope compaction selected by the Contractor fails to
produce the necessary results, the Contractor should rework or rebuild such
slopes until the required degree of compaction is obtained, at no additional
cost to the Owner or Geotechnical Engineer. Slope testing will include testing
the outer 6 inches to 3 feet of the slope face during and after placement of the
Page 35 July 19, 2022
W.O. 7726
(Revised July 28, 2022)
MDN 23013A
fill. In addition, during grading, density tests will be taken periodically on the
flat surface of the fill three to five feet horizontally from the face of the slope.
Slope Face - Contractor’s Responsibility: The Contractor should prepare a
written detailed description of the method or methods he would employ to
obtain the required slope compaction. Such documents should be submitted
to the Geotechnical Engineer for review and comments prior to the start of
grading.
Slope Face - Vegetation: All fill slopes should be planted or protected from
erosion by methods specified in the geotechnical report, or required by the
controlling governmental agency.
Density Testing Intervals: In general, density tests should be conducted at
minimum intervals of 2 feet of fill height or every 500 to 1,000 cubic yards.
Due to the variability that can occur in fill placement and different fill material
characteristics, a higher number of density tests may be warranted to verify
that the required compaction is being achieved.
Grading Control: Earthwork monitoring and field density testing shall be
performed by the Geotechnical Engineer during grading to provide a basis for
opinions concerning the degree of soil compaction attained. The Contractor
should receive a copy of the Geotechnical Engineer's Daily Field Engineering
Report which will indicate the results of field density tests for that day. Where
failing tests occur or other field problems arise, the Contractor shall be
notified of such conditions by written communication from the Geotechnical
Engineer in the form of a conference memorandum, to avoid any
misunderstanding arising from oral communication.
Drainage Devices: Drainage terraces should be constructed in compliance
with the ordinances of controlling governmental agencies, or with the
recommendations of the Geotechnical Engineer or Engineering Geologist.
Page 36 July 19, 2022
W.O. 7726
(Revised July 28, 2022)
MDN 23013A
6.8.4 Construction Considerations
Erosion Control: Erosion control measures, when necessary, should be
provided by the Contractor during grading and prior to the completion and
construction of permanent drainage controls.
Compaction Equipment: It is also the Contractor's responsibility to have
suitable and sufficient compaction equipment on the project site to handle the
amount of fill being placed and the type of fill material to be compacted. If
necessary, excavation equipment should be shut down to permit completion
of compaction in accordance with the recommendations contained herein.
Sufficient watering devices/equipment should also be provided by the
Contractor to achieve optimum moisture content in the fill material.
Final Grading Considerations: Care should be taken by the Contractor during
final grading to preserve any berms, drainage terraces, interceptor swales, or
other devices of a permanent nature on or adjacent to the property.
6.8.5 Earthwork Adjustment Factors
The following table presents shrinkage factors as based on laboratory testing
of the alluvium.
TABLE 8
EARTHWORK ADJUSTMENT FACTORS
Material Type Adjustment Factor
Alluvium 5 to 10% (shrinkage)
6.8.6 Temporary Excavation
Where the necessary space is available, temporary unsurcharged
embankments may be sloped back without shoring. The slope should not be
cut steeper than the following gradient:
Page 37 July 19, 2022
W.O. 7726
(Revised July 28, 2022)
MDN 23013A
TABLE 9 TEMPORARY EXCAVATION SLOPE
Height Temporary Gradient
(Horizontal:Vertical)
0 - 5' Near Vertical
above 5' 1:1
In areas where soils with little or no binder are encountered, shoring or flatter
excavation slopes shall be made. These recommended temporary
excavation slopes do not preclude local ravelling or sloughing.
All applicable requirements of the California Construction and General
Industry Safety Orders, the Occupational Safety and Health Act, and the
Construction Safety Act should be met.
Where sloped embankments are used, the top of the slope should be
barricaded to prevent equipment and heavy storage loads within five feet of
the top of the slope. If the temporary construction embankments are to be
maintained for long periods, berms should be constructed along the top of the
slope to prevent runoff water from eroding the slope faces. The soils
exposed in the temporary backcut slopes during excavation should be
observed by our personnel so that modifications of the slopes can be made if
variations in the soil conditions occur. The temporary excavation slopes
should be supported within three weeks.
6.8.7 Excavation Observation
All footing and other excavations should be observed by an Engineering
Geologist or Geotechnical Engineering prior to placement of any steel to
verify that the proper foundation material has been encountered. The City
Inspector should also observe the excavation.
Page 38 July 19, 2022
W.O. 7726
(Revised July 28, 2022)
MDN 23013A
6.8.8 Utility Trenching and Backfill
Utility Trenching: Open excavations and excavations that are shored shall
conform to all applicable Federal, State, and local regulations.
Backfill Placement: Approved on-site or imported fill material shall be evenly
placed, watered, processed, and compacted in controlled horizontal layers
not exceeding eight inches in loose thickness, and each layer should be
thoroughly compacted with approved equipment. All fill material should be
moisture conditioned, as required to obtain at least optimum moisture, but not
greater than 120 percent of optimum moisture content. The fill should be
placed and compacted on a horizontal plane, unless otherwise recommended
by the Geotechnical Engineer.
As an alternative to on-site or imported fill material, for shallow trenches
where pipe or utility lines may be damaged by mechanical compaction
equipment, such as under building floor slabs, imported clean sand having a
sand equivalent (SE) value of 30 or greater may be utilized. The sand backfill
materials should be watered to achieve near optimum moisture conditions
and then tamped into place. No specific relative compaction will be required;
however, observation, probing, and if deemed necessary, testing should be
performed by a representative of the project geotechnical consultant to verify
an adequate degree of compaction.
Backfill Compaction Criteria: Each layer of utility trench backfill shall be
compacted to at least 90 percent of the maximum laboratory density
determined by ASTM D-1557-12. The field density shall be determined by
the ASTM D-1556-07 method or equivalent. Where moisture content of the fill
or density testing yields compaction results less than 90 percent, additional
compaction effort and/or moisture conditioning, as necessary, shall be
performed, until the compaction criteria is reached.
Page 39 July 19, 2022
W.O. 7726
(Revised July 28, 2022)
MDN 23013A
Exterior Trenches Adjacent to Footings: Exterior trenches, paralleling a
footing and extending below a 1H:1V plane projected from the outside bottom
edge of the footing, should be compacted to 90 percent of the laboratory
standard. Sand backfill, unless it is similar to the in-place fill, should not be
allowed in the trench backfill areas. Density testing, along with probing,
should be accomplished to verify the desired results.
Pipe Bedding: We recommend that a minimum of 6 inches of bedding
material should be placed in the bottom of the utility trench. All bedding
materials shall extend at least 4 inches above the top of utilities which require
protection during subsequent trench backfilling. All trenches shall be wide
enough to allow for compaction around the haunches of the pipe.
Groundwater Migration: Backfilled utility trenches may act as French drains
to some extent, and considerable groundwater flow along utility bedding and
backfill should be expected. Wherever buried utilities, or structures which
they may intersect, could be adversely affected by such drainage, provisions
shall be made to collect groundwater migrating along the trench lines. These
situations include where buried utilities enter buildings, particularly where they
enter below grade mechanical rooms, and where buried utilities enter junction
boxes or switching stations that are intended to remain dry. Mitigation
measures include, but are not limited to, placement of perforated drain pipes
below and continuous with bedding materials, and placement of seepage
barriers such as lean mix concrete or controlled density fill (CDF).
7.0 CLOSURE
We appreciate this opportunity to be of continued service to you. If you have any questions
regarding the content of this report or any other aspects of the project, please do not
hesitate to contact us.
Page 40 July 19, 2022
W.O. 7726
(Revised July 28, 2022)
MDN 23013A
REFERENCES
1 California Geological Survey, 2005, Seismic Hazard Zone Report 095, Seismic Hazard
Zone Report for the Lancaster West 7.5-Minute Quadrangle, Los Angeles County,
California”
2 California Building Code (CBC), 2019, California Code of Regulations, Title 24, Part 2,
Volume I and II.
B-3B-7
B-1B-5
B-6 B-4
B-8/P-1
B-9/P-2
B-2
B-3B-7
B-6 B-4
B-8/P-1
B-9/P-2
EXPLANATION
APPROXIMATE LOCATION OF BORINGB-7
WORK ORDER DATE SCALE
REVISED PLATE 1
6634 Valjean Avenue
Van Nuys, CA 91406
GEOTECHNICAL GEOLOGIC ENVIRONMENTAL
GeoSoils Consultants Inc.GSC
7726 7/2022 1" = 30'
PROPOSED RESIDENTIAL DEVELOPMENT
NORTH CORNER OF CHASE ROAD & ARIA LANE
FONTANA, CALIFORNIA
RIDGECREST REAL ESTATE, LLC.
MDN 23013A
P-2
APPROXIMATE LOCATION OF PERCOLATION TEST
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6634 Valjean Avenue, Van Nuys, California 91406 Phone: (818) 785-2158 Fax: (818) 785-1548
MDN 23013A
July 19, 2022 W.O. 7726
(Revised July 28, 2022)
APPENDIX A
FIELD EXPLORATION RESULTS
PROJECT NAME W.O.
DRILLING COMPANY 2R DATE STARTED 5/10/2022 B-1
TYPE OF DRILL RIG Truck Mounted LOGGED BY RM SHEET
DRILLING METHOD Hollow Stem HAMMER WT (lbs)140
DIAMETER OF HOLE (IN)8 DROP (IN)30
Boring Location:
De
p
t
h
(
f
t
)
Bl
o
w
s
/
6
"
Mo
i
s
t
u
r
e
Co
n
t
e
n
t
(
%
)
Dr
y
D
e
n
s
i
t
y
(p
c
f
)
Ot
h
e
r
T
e
s
t
s
0
5 12/12/16 1.5 SIEVE
moderately moist, loose
33/44/50 2.1 137.6 CONS
10 18/19/22 0.6 SIEVE
38/50 4.5 117.2 CONS
15 20/35/50 SIEVE
20 20/50 for 3"2.8
25 22/32/31
30 50 for 4"
PLATE A-1
Standard Penetration Test
California Ring
Rock Core
Bulk Sample
LEGEND
15', Gray brown, gravelly sand, semi-angular, up to 2", moist, medium dense
to dense
dense
25', Light brown, gravelly sand, semi-angular, up to 1", moist, medium
moist, dense
20', Brown, gravelly sand, semi-angular to rounded, up to 1", moist to very
SIEVE: Grain Size Analysis
#200: Washed Seive #200
MAX: Maximum Dry Density
DS: Direct Shear
C/S: Collapse/Swell
CONS: Consolidation
HYDR: Hydrometer Analysis
EXPAN: Expansion Index
CHEM: Chemical Tests
R-V: R-Value
PI: Atterberge Limits Tests
10', Gray to gray brown, sandy gravel, angular, up to 2", moist, medium dense
12.5', Brown, sandy gravel, semi-angular, up to 2", moist, medium dense
Some caving
No groundwater
TD=30'
30', No recovery
BORING NO.
GW ELEV.
Sa
m
p
l
e
Ty
p
e
GEOTECHNICAL BORING LOG
GROUND ELEV.
GEOTECHNICAL DESCRIPTION
Ridgecrest 7726
5', Gray brown and brown, fine to coarse sand with some gravel up to 2",
7.5', Mottley brown and black, sandy gravel, up to 2", moist, medium dennse
PROJECT NAME W.O.
DRILLING COMPANY 2R DATE STARTED 5/10/2022 B-2
TYPE OF DRILL RIG Truck Mounted LOGGED BY RM SHEET
DRILLING METHOD Hollow Stem HAMMER WT (lbs)140
DIAMETER OF HOLE (IN)8 DROP (IN)30
Boring Location:
De
p
t
h
(
f
t
)
Bl
o
w
s
/
6
"
Mo
i
s
t
u
r
e
Co
n
t
e
n
t
(
%
)
Dr
y
D
e
n
s
i
t
y
(p
c
f
)
Ot
h
e
r
T
e
s
t
s
0
3.7
5 5/9/9 3.4 128..6
12/17/22
10 4/17/50 3.0 127.4
28/33/33
15 40/50 for 5"2.7 113.2
20 20/49/45
25 50 for 4"3.3
30 50
PLATE A-2
Standard Penetration Test
California Ring
Rock Core
Bulk Sample
TD=30'
No groundwater
Some caving
LEGEND SIEVE: Grain Size Analysis
#200: Washed Seive #200
MAX: Maximum Dry Density
DS: Direct Shear
C/S: Collapse/Swell
CONS: Consolidation
HYDR: Hydrometer Analysis
EXPAN: Expansion Index
CHEM: Chemical Tests
R-V: R-Value
PI: Atterberge Limits Tests
30', Gray brown, gravelly sand, grvel up to 1", moist
20', Gray brown, gravelly sand, gravel up to 1.5", Sampler was cutting
through a larger rock, moderately moist, dense
25', Brown, gravelly sand, gravel up to 2", some silt, moist, dense
7.5', Gray brown and light grown, gravelly sand with some silt, moist,
medium dense
10', Brown, gravelly sand, moist to very moist, gravel up to 2", medium
dense
12.5', Gray brown, gravelly sand, gravel up to 1", semi-angular, dense,
moist
15', Gray brown, gravelly sand, gravel up to 1", semi-angular, slightly
moist, dense, some silt and carbonate present
5', Light brown, sand gravel, up to ½", moist, loose
GEOTECHNICAL BORING LOG
Ridgecrest 7726
BORING NO.
GROUND ELEV.
GW ELEV.
Sa
m
p
l
e
Ty
p
e GEOTECHNICAL DESCRIPTION
PROJECT NAME W.O.
DRILLING COMPANY 2R DATE STARTED 5/10/2022 B-3
TYPE OF DRILL RIG Truck Mounted LOGGED BY RM SHEET
DRILLING METHOD Hollow Stem HAMMER WT (lbs)140
DIAMETER OF HOLE (IN)8 DROP (IN)30
Boring Location:
De
p
t
h
(
f
t
)
Bl
o
w
s
/
6
"
Mo
i
s
t
u
r
e
Co
n
t
e
n
t
(
%
)
Dr
y
D
e
n
s
i
t
y
(p
c
f
)
Ot
h
e
r
T
e
s
t
s
0 MAX
R-V, SIEVE
1.5
5 6/15/12 2.4 SIEVE
loose
15/26/32 2.7 132.9 CONS
10 18/15/18 2.8 SIEVE
42/35/50 4.9 133.5
15 16/26/6
20 50 for 3"3.4 118.2
25 20/24/34
30 37/50 for 4"4.4 110.4
PLATE A-3
Standard Penetration Test
California Ring
Rock Core
Bulk Sample
TD=30'
No groundwater
Some caving
LEGEND SIEVE: Grain Size Analysis
#200: Washed Seive #200
MAX: Maximum Dry Density
DS: Direct Shear
C/S: Collapse/Swell
CONS: Consolidation
HYDR: Hydrometer Analysis
EXPAN: Expansion Index
CHEM: Chemical Tests
R-V: R-Value
PI: Atterberge Limits Tests
30', Gray brown, gravelly sand, slightly moist, loose to moderately dense
20', Gray brown, gravelly sand, gravel up to 2", semi-angular, slightly
moist, dense
25', Brown, silty, fine sand, very moist, and gray brown, gravelly, fine to
coarse, sand, moist, dense
7.5', Light brown, gravelly sand, gravel up to 1", semi-angular, moist to
very moist, dense
10', Brown, gravelly sand, gravel up to 1", cut from larger rock, rounded,
moist, loose to moderately dense
12.5', Brown, gravelly sand, gravel up to 3/4", semi-angular, moist to very moist,
dense to very dense
15', Gray brown to black, gravelly sand, gravel up to 1", semi-angular,
moist, moderately dense
5', Light brown, silty, gravelly sand, gravel up to 1.5", moist to very moist,
GEOTECHNICAL BORING LOG
Ridgecrest 7726
BORING NO.
GROUND ELEV.
GW ELEV.
Sa
m
p
l
e
Ty
p
e GEOTECHNICAL DESCRIPTION
PROJECT NAME W.O.
DRILLING COMPANY 2R DATE STARTED 5/10/2022 B-4
TYPE OF DRILL RIG Truck Mounted LOGGED BY RM SHEET
DRILLING METHOD Hollow Stem HAMMER WT (lbs)140
DIAMETER OF HOLE (IN)8 DROP (IN)30
Boring Location:
De
p
t
h
(
f
t
)
Bl
o
w
s
/
6
"
Mo
i
s
t
u
r
e
Co
n
t
e
n
t
(
%
)
Dr
y
D
e
n
s
i
t
y
(p
c
f
)
Ot
h
e
r
T
e
s
t
s
0 MAX
R-V, SIEVE
0.5
5 15/20/27 2.4
25/40/43 3.3 136.1 CONS
10 21/27/31 3.1
15 41/50 for 6"2.5 143.8
20 20/39/39
25 50 for 4"
30 50 for 4"
PLATE A-4
Standard Penetration Test
California Ring
Rock Core
Bulk Sample
TD=30'
No groundwater
Some caving
LEGEND SIEVE: Grain Size Analysis
#200: Washed Seive #200
MAX: Maximum Dry Density
DS: Direct Shear
C/S: Collapse/Swell
CONS: Consolidation
HYDR: Hydrometer Analysis
EXPAN: Expansion Index
CHEM: Chemical Tests
R-V: R-Value
PI: Atterberge Limits Tests
30', No recovery
20', Light brown, silty, gravelly sand, gravel up to 1", moist to very moist,
dense
25', No recovery
7.5', Light brown, gravelly sand, gravel up to 1.5", moist, dense
10', Light brown, gravelly sand, gravel up to 1.5', moist, dense
15', Brown, gravelly sand, gravel up to 1", moist, dense
5', Yellowish brown, gravelly sand with some silt, moist, moderately moist
GEOTECHNICAL BORING LOG
Ridgecrest 7726
BORING NO.
GROUND ELEV.
GW ELEV.
Sa
m
p
l
e
Ty
p
e GEOTECHNICAL DESCRIPTION
PROJECT NAME W.O.
DRILLING COMPANY 2R DATE STARTED 5/11/2022 B-2
TYPE OF DRILL RIG Truck Mounted LOGGED BY RM SHEET
DRILLING METHOD Hollow Stem HAMMER WT (lbs)140
DIAMETER OF HOLE (IN)8 DROP (IN)30
Boring Location:
De
p
t
h
(
f
t
)
Bl
o
w
s
/
6
"
Mo
i
s
t
u
r
e
Co
n
t
e
n
t
(
%
)
Dr
y
D
e
n
s
i
t
y
(p
c
f
)
Ot
h
e
r
T
e
s
t
s
0
5 37/50 for 5"1.3 148.6 CONS
loose, and gray gravelly sand, gravel up to 1.5", dry, dense
13/24/40 3.3
10 23/50 for 5"1.9 141.5 CONS
20/27/27
15 35/50 for 5"2.5 139.8
20 16/9/16
25 7/15/50 3.5 129.3
30 40/50 for 5"
PLATE A-5
Standard Penetration Test
California Ring
Rock Core
Bulk Sample
TD=30'
No groundwater
Some caving
LEGEND SIEVE: Grain Size Analysis
#200: Washed Seive #200
MAX: Maximum Dry Density
DS: Direct Shear
C/S: Collapse/Swell
CONS: Consolidation
HYDR: Hydrometer Analysis
EXPAN: Expansion Index
CHEM: Chemical Tests
R-V: R-Value
PI: Atterberge Limits Tests
30', Gray brown, gravelly sand, dry to moderately moist, dense
20', Light brown, gravelly, silty sand, moist, loose to moderately dense
25', Brown, gravelly, silty sand, moist, moderately dense and gray brown,
gravelly sand, moderately moist, dense
7.5', Light brown, gravelly sand with some silt, gravel up to 1.5",
moderately moist, medium dense
10', Brown, gravelly sand, gravel up to 2", moderately moist to moist,
loose to moderately dense
12.5', Gray brown, gravelly sand, gravel up to 1", possibly from larger
rock, dry to moderately moist, loose to moderately dense
15', Gray brown, gravelly sand, gravel up to 2", from larger rock,
moderately moist
5', Yellowish brown, silty, gravelly sand, gravel up to ½", slightly moist,
GEOTECHNICAL BORING LOG
Ridgecrest 7726
BORING NO.
GROUND ELEV.
GW ELEV.
Sa
m
p
l
e
Ty
p
e GEOTECHNICAL DESCRIPTION
PROJECT NAME W.O.
DRILLING COMPANY 2R DATE STARTED 5/11/2022 B-6
TYPE OF DRILL RIG Truck Mounted LOGGED BY RM SHEET
DRILLING METHOD Hollow Stem HAMMER WT (lbs)140
DIAMETER OF HOLE (IN)8 DROP (IN)30
Boring Location:
De
p
t
h
(
f
t
)
Bl
o
w
s
/
6
"
Mo
i
s
t
u
r
e
Co
n
t
e
n
t
(
%
)
Dr
y
D
e
n
s
i
t
y
(p
c
f
)
Ot
h
e
r
T
e
s
t
s
0
5
10
15 43/50 for 3'2.1 135.9 SIEVE
20
25
30
PLATE A-6
Standard Penetration Test
California Ring
Rock Core
Bulk Sample
LEGEND SIEVE: Grain Size Analysis
#200: Washed Seive #200
MAX: Maximum Dry Density
DS: Direct Shear
C/S: Collapse/Swell
CONS: Consolidation
HYDR: Hydrometer Analysis
EXPAN: Expansion Index
CHEM: Chemical Tests
R-V: R-Value
PI: Atterberge Limits Tests
No caving
No groundwater
15', Gray brown, gravelly sand, dry to moderately moist, loose (hit large rocks
multiple times as shown oin sample and top of tube)
TD=15'
GEOTECHNICAL BORING LOG
Ridgecrest 7726
BORING NO.
GROUND ELEV.
GW ELEV.
Sa
m
p
l
e
Ty
p
e GEOTECHNICAL DESCRIPTION
PROJECT NAME W.O.
DRILLING COMPANY 2R DATE STARTED 5/11/2022 B-7
TYPE OF DRILL RIG Truck Mounted LOGGED BY RM SHEET
DRILLING METHOD Hollow Stem HAMMER WT (lbs)140
DIAMETER OF HOLE (IN)8 DROP (IN)30
Boring Location:
De
p
t
h
(
f
t
)
Bl
o
w
s
/
6
"
Mo
i
s
t
u
r
e
Co
n
t
e
n
t
(
%
)
Dr
y
D
e
n
s
i
t
y
(p
c
f
)
Ot
h
e
r
T
e
s
t
s
0
1.3
5 8/14/18 1.7 SEIVE
loose to moderately dense
25/32/25 2.7 141.5 CONS
10 11/25/30 2.7 SIEVE
10/15/21
15 50 for 5"
20 50 for 3"
50 for 2"
17/29/29
25 50 for 5"0.8
30', No recovery (bouncing off large rock)
30 50 for 1"31'. Gray and grayish brown, gravelly sand, cutting through larger rock,
35/50 for 5"moderately moist, dense
No groundwater
Some caving
PLATE A-7
Standard Penetration Test
California Ring
Rock Core
Bulk Sample
TD=30'
LEGEND SIEVE: Grain Size Analysis
#200: Washed Seive #200
MAX: Maximum Dry Density
DS: Direct Shear
C/S: Collapse/Swell
CONS: Consolidation
HYDR: Hydrometer Analysis
EXPAN: Expansion Index
CHEM: Chemical Tests
R-V: R-Value
PI: Atterberge Limits Tests
25', Gray brown, gravelly sand, dry to moderately moist, large rock on
lower portion of tube up to 2-2.5", dense
gravelly sand, most, dense
dense, gravel up to 1'
15', No recovery (large rock wedged into tube)
20', No recovery (bouncing off large rock)
22.5', No recovery (bouncing off large rock)
23', Brown, gravelly, silty sand, very moist, dense and light brown, silty,
12.5', Brown, gravelly sand, moderatel moist to moist, loose to moderately
Sa
m
p
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e
Ty
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e GEOTECHNICAL DESCRIPTION
5', Yellowish brown, silty, gravelly sand, gravel up to 1", dry to moderately moist,
7.5', Mottled yellowish brown and gray brown, silty, gravelly sand, dry to
moderately moist, dense
10', Brown, gravelly, silty sand, moderately moist, dense, gravel up to 1"
GW ELEV.
GEOTECHNICAL BORING LOG
Ridgecrest 7726
BORING NO.
GROUND ELEV.
6634 Valjean Avenue, Van Nuys, California 91406 Phone: (818) 785-2158 Fax: (818) 785-1548
MDN 23013A
July 19, 2022
W.O. 7726
(Revised July 28, 2022)
APPENDIX B
LABORATORY TEST RESULTS
EXPANSION INDEX TEST
ASTM D-4829
Ridgecrest
7726
Project Information
Project Name:Ridgecrest
Work Order No.:7726
Date of Test:14-Jul-22
Tract Number:
Constants
Vol. wet soil (cf):0.0073
Calculations Specific Gravity:2.70
Boring/Lot #:B-3 B-4
Depth of Test (ft):0-5.0'0-5.0'
Soil Classification:Brown silty very fine to
coarse SAND.
Brown silty very fine to
coarse SAND.
Wet Weight + Ring (lbs):1.3545 1.3455
Ring Weight (lbs):0.4280 0.4295
Wet Weight (lbs):0.9265 0.9160
Wet Density (pcf):126.9 125.5
Moisture (%):8.3 9.1
Dry Density (pcf):117.2 115.0
Saturation (%):51.2 52.9
Initial Reading:0.4140 0.4230
Final Reading:0.4190 0.4340
Expansion, H, (inches):0.0050 0.0110
Expansion Index:5 12
Expansion Potential:Very Low Very Low
After Test
Wet Weight (g):436.0 439.9
Dry Weight (g):384.1 368.0
Water Loss (g):51.9 71.9
Moisture (%):13.5 19.5
Expansion Index Table:0 - 20 = Very Low
21 - 50 = Low
51 - 90 = Medium
91 - 130 = High
130 & Up = Very High
EI7726.1.xls
CLEINT:
WORK ORDER:
TEST DATE:
SAMPLE:
SOIL CLASSIFICATION:
with abundant rock fragments.
Init. Moisture Content (%)4.05 % Hydroconsolidation:-1.0
Init. Dry Density (PCF)121.5 Total Consolidation @ 16 tsf -10.4
Init. Void Ratio 0.38
Ridgecrest
7726
7/1/2022
B-1 @ 7.5'
Brown very fine to coarse SAND
Plate: C-1CONSOLIDATION TEST DIAGRAM
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
0.01 0.1 1 10 100
Normal Pressure (tsf)
Consolidation-Normal Pressure Curve
Co
n
s
o
l
i
d
a
t
i
o
(
%
)
Water Added @ 1.0 tsf
CLEINT:
WORK ORDER:
TEST DATE:
SAMPLE:
SOIL CLASSIFICATION:
Init. Moisture Content (%)4.79 % Hydroconsolidation:-0.6
Init. Dry Density (PCF)122.6 Total Consolidation @ 16 tsf -8.6
Init. Void Ratio 0.41
Plate: C-2CONSOLIDATION TEST DIAGRAM
Ridgecrest
7726
7/1/2022
B-1 @ 12.5'
Brown silty very fine to coarse SAND.
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
0.01 0.1 1 10 100
Normal Pressure (tsf)
Consolidation-Normal Pressure Curve
Co
n
s
o
l
i
d
a
t
i
o
(
%
)
Water Added @ 1.0 tsf
CLEINT:
WORK ORDER:
TEST DATE:
SAMPLE:
SOIL CLASSIFICATION:
Init. Moisture Content (%)4.15 % Hydroconsolidation:-0.2
Init. Dry Density (PCF)118.5 Total Consolidation @ 16 tsf -6.2
Init. Void Ratio 0.39
Ridgecrest
7726
7/1/2022
B-3 @ 7.5'
Brown slightly silty very fine to coarse SAND.
Plate: C-3CONSOLIDATION TEST DIAGRAM
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
0.01 0.1 1 10 100
Normal Pressure (tsf)
Consolidation-Normal Pressure Curve
Co
n
s
o
l
i
d
a
t
i
o
(
%
)
Water Added @ 1.0 tsf
CLEINT:
WORK ORDER:
TEST DATE:
SAMPLE:
SOIL CLASSIFICATION:
with abundant rock fragments.
Init. Moisture Content (%)5.31 % Hydroconsolidation:-1.6
Init. Dry Density (PCF)117.2 Total Consolidation @ 16 tsf -11.9
Init. Void Ratio 0.39
Plate: C-4CONSOLIDATION TEST DIAGRAM
Ridgecrest
7726
7/5/2022
B-4 @ 7.5'
Brown slightly silty fine to coarse SAND
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
0.01 0.1 1 10 100
Normal Pressure (tsf)
Consolidation-Normal Pressure Curve
Co
n
s
o
l
i
d
a
t
i
o
(
%
)
Water Added @ 1.0 tsf
CLEINT:
WORK ORDER:
TEST DATE:
SAMPLE:
SOIL CLASSIFICATION:
SAND with abundant rock fragments.
Init. Moisture Content (%)3.18 % Hydroconsolidation:-1.8
Init. Dry Density (PCF)124.9 Total Consolidation @ 16 tsf -9.9
Init. Void Ratio 0.33
Ridgecrest
7726
7/5/2022
B-5 @ 5.0'
Light brown slightly silty fine to coarse
Plate: C-5CONSOLIDATION TEST DIAGRAM
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
0.01 0.1 1 10 100
Normal Pressure (tsf)
Consolidation-Normal Pressure Curve
Co
n
s
o
l
i
d
a
t
i
o
(
%
)
Water Added @ 1.0 tsf
CLEINT:
WORK ORDER:
TEST DATE:
SAMPLE:
SOIL CLASSIFICATION:
with rock fragments.
Init. Moisture Content (%)3.13 % Hydroconsolidation:-1.3
Init. Dry Density (PCF)127.0 Total Consolidation @ 16 tsf -7.3
Init. Void Ratio 0.30
Plate: C-6CONSOLIDATION TEST DIAGRAM
Ridgecrest
7726
7/5/2022
B-5 @ 10.0'
Gray brown very fine to coarse SAND
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
0.01 0.1 1 10 100
Normal Pressure (tsf)
Consolidation-Normal Pressure Curve
Co
n
s
o
l
i
d
a
t
i
o
(
%
)
Water Added @ 1.0 tsf
CLEINT:
WORK ORDER:
TEST DATE:
SAMPLE:
SOIL CLASSIFICATION:
SAND with rock fragments.
Init. Moisture Content (%)3.90 % Hydroconsolidation:-1.5
Init. Dry Density (PCF)124.0 Total Consolidation @ 16 tsf -8.8
Init. Void Ratio 0.33
Ridgecrest
7726
7/5/2022
B-7 @ 7.5'
Brown slightly silty very fine to coarse
Plate: C-7CONSOLIDATION TEST DIAGRAM
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
0.01 0.1 1 10 100
Normal Pressure (tsf)
Consolidation-Normal Pressure Curve
Co
n
s
o
l
i
d
a
t
i
o
(
%
)
Water Added @ 1.0 tsf
Ridgecrest
W.O. 7726
Date of Test: 7/22
GeoSoils Consultants, Inc.
Geotechnical Engineering * Engineering Geology
Moisture (%): 1.5
Liquid Limit (%):
Plastic Limit (%):
Plasticity Index :
B-1 @ 5.0'
Gray brown slightly silty very fine to coarse SAND with rock fragments.SH7726.1 Plate G-1
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.11101001000
Pe
r
c
e
n
t
F
i
n
e
r
B
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W
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i
g
h
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Diameter (mm) Grain Size Analysis
By Sieve By Hydrometer
COARSE FINE COARSE MEDIUM FINE COBBLES GRAVEL SAND SILT CLAY
Size of Opening In Inches Sieve Mesh Number 12 3 3/4 4 10 20 40 60 200
Ridgecrest
W.O. 7726
Date of Test: 7/22
GeoSoils Consultants, Inc.
Geotechnical Engineering * Engineering Geology
Moisture (%): 0.6
Liquid Limit (%):
Plastic Limit (%):
Plasticity Index :
B-1 @ 10.0'
Gray brown very fine to coarse SAND with rock fragments.SH7726.2 Plate G-2
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.11101001000
Pe
r
c
e
n
t
F
i
n
e
r
B
y
W
e
i
g
h
t
Diameter (mm) Grain Size Analysis
By Sieve By Hydrometer
COARSE FINE COARSE MEDIUM FINE COBBLES GRAVEL SAND SILT CLAY
Size of Opening In Inches Sieve Mesh Number 12 3 3/4 4 10 20 40 60 200
Ridgecrest
W.O. 7726
Date of Test: 7/22
GeoSoils Consultants, Inc.
Geotechnical Engineering * Engineering Geology
Moisture (%): 2.5
Liquid Limit (%):
Plastic Limit (%):
Plasticity Index :
B-1 @ 15.0'
Gray brown slightly silty very fine to coarse SAND.SH7726.3 Plate G-3
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.11101001000
Pe
r
c
e
n
t
F
i
n
e
r
B
y
W
e
i
g
h
t
Diameter (mm) Grain Size Analysis
By Sieve By Hydrometer
COARSE FINE COARSE MEDIUM FINE COBBLES GRAVEL SAND SILT CLAY
Size of Opening In Inches Sieve Mesh Number 12 3 3/4 4 10 20 40 60 200
Ridgecrest
W.O. 7726
Date of Test: 7/22
GeoSoils Consultants, Inc.
Geotechnical Engineering * Engineering Geology
Moisture (%): 1.5
Liquid Limit (%):
Plastic Limit (%):
Plasticity Index :
B-3 @ 0-5.0'
Brown silty very fine to coarse SAND with rock fragments.SH7726.4 Plate G-4
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.11101001000
Pe
r
c
e
n
t
F
i
n
e
r
B
y
W
e
i
g
h
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Diameter (mm) Grain Size Analysis
By Sieve By Hydrometer
COARSE FINE COARSE MEDIUM FINE COBBLES GRAVEL SAND SILT CLAY
Size of Opening In Inches Sieve Mesh Number 12 3 3/4 4 10 20 40 60 200
Ridgecrest
W.O. 7726
Date of Test: 7/22
GeoSoils Consultants, Inc.
Geotechnical Engineering * Engineering Geology
Moisture (%): 2.4
Liquid Limit (%):
Plastic Limit (%):
Plasticity Index :
B-3 @ 5.0'
Brown silty very fine to coarse SAND.SH7726.5 Plate G-5
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.11101001000
Pe
r
c
e
n
t
F
i
n
e
r
B
y
W
e
i
g
h
t
Diameter (mm) Grain Size Analysis
By Sieve By Hydrometer
COARSE FINE COARSE MEDIUM FINE COBBLES GRAVEL SAND SILT CLAY
Size of Opening In Inches Sieve Mesh Number 12 3 3/4 4 10 20 40 60 200
Ridgecrest
W.O. 7726
Date of Test: 7/22
GeoSoils Consultants, Inc.
Geotechnical Engineering * Engineering Geology
Moisture (%): 2.8
Liquid Limit (%):
Plastic Limit (%):
Plasticity Index :
B-3 @ 10.0'
Brown slightly silty very fine to coarse SAND.SH7726.6 Plate G-6
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.11101001000
Pe
r
c
e
n
t
F
i
n
e
r
B
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W
e
i
g
h
t
Diameter (mm) Grain Size Analysis
By Sieve By Hydrometer
COARSE FINE COARSE MEDIUM FINE COBBLES GRAVEL SAND SILT CLAY
Size of Opening In Inches Sieve Mesh Number 12 3 3/4 4 10 20 40 60 200
Ridgecrest
W.O. 7726
Date of Test: 7/22
GeoSoils Consultants, Inc.
Geotechnical Engineering * Engineering Geology
Moisture (%): 0.5
Liquid Limit (%):
Plastic Limit (%):
Plasticity Index :
B-4 @ 0-5.0'
Light brown slightly silty very fine to coarse SAND.SH7726.7 Plate G-7
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.11101001000
Pe
r
c
e
n
t
F
i
n
e
r
B
y
W
e
i
g
h
t
Diameter (mm) Grain Size Analysis
By Sieve By Hydrometer
COARSE FINE COARSE MEDIUM FINE COBBLES GRAVEL SAND SILT CLAY
Size of Opening In Inches Sieve Mesh Number 12 3 3/4 4 10 20 40 60 200
Ridgecrest
W.O. 7726
Date of Test: 7/22
GeoSoils Consultants, Inc.
Geotechnical Engineering * Engineering Geology
Moisture (%): 2.1
Plastic Limit (%):
Plasticity Index :
B-6 @ 15.0'
Gray brown slightly silty very fine to coarse SAND with rock fragments.SH7726.8 Plate G-8
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.11101001000
Pe
r
c
e
n
t
F
i
n
e
r
B
y
W
e
i
g
h
t
Diameter (mm) Grain Size Analysis
By Sieve By Hydrometer
COARSE FINE COARSE MEDIUM FINE COBBLES GRAVEL SAND SILT CLAY
Size of Opening In Inches Sieve Mesh Number 12 3 3/4 4 10 20 40 60 200
Ridgecrest
W.O. 7726
Date of Test: 7/22
GeoSoils Consultants, Inc.
Geotechnical Engineering * Engineering Geology
Moisture (%): 1.7
Plastic Limit (%):
Plasticity Index :
B-7 @ 5.0'
Light brown silty very fine to coarse SAND.SH7726.9 Plate G-9
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.11101001000
Pe
r
c
e
n
t
F
i
n
e
r
B
y
W
e
i
g
h
t
Diameter (mm) Grain Size Analysis
By Sieve By Hydrometer
COARSE FINE COARSE MEDIUM FINE COBBLES GRAVEL SAND SILT CLAY
Size of Opening In Inches Sieve Mesh Number 12 3 3/4 4 10 20 40 60 200
Ridgecrest
W.O. 7726
Date of Test: 7/22
GeoSoils Consultants, Inc.
Geotechnical Engineering * Engineering Geology
Moisture (%): 2.7
Plastic Limit (%):
Plasticity Index :
B-7 @ 10.0'
Brown silty very fine to coarse SAND.SH7726.10 Plate G-10
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0.00010.0010.010.11101001000
Pe
r
c
e
n
t
F
i
n
e
r
B
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W
e
i
g
h
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Diameter (mm) Grain Size Analysis
By Sieve By Hydrometer
COARSE FINE COARSE MEDIUM FINE COBBLES GRAVEL SAND SILT CLAY
Size of Opening In Inches Sieve Mesh Number 12 3 3/4 4 10 20 40 60 200
Client:
Work Order:
Test Date:
Sample:
Soil Classification:
Compaction Procedure:
Lab and QC by:
132.5
OPTIMUM MOISTURE CONTENT (%):8.5
A Mold diameter (in)4 4 4 4 4
B Mold height (in)4.581 4.581 4.581 4.581 4.581
C Wt. of Mold (g)4276 4276 4276 4276 4276
D Moist Soil + Mold (g)6416 6459 6453 0 0
E Soil Wt. (g)2140 2183 2177 -4276 -4276
F Volume of mold (ft3)0.0334 0.0334 0.0334 0.0334 0.0334GVolume of mold (cm3)944.99 944.99 944.99 944.99 944.99
H Moist Density (g/cm3)2.26457 2.3100774 2.303728082 -4.524916 -4.52492
M Wt. of wet soil (g)200 200 200 200 200
N Wt. of dry soiltare (g)186.2 183.8 182.2 176.1 175OWt. of water (g)13.8 16.2 17.8 23.9 25
P Moisture Content (%)7.4 8.8 9.8 #N/A #N/A
Q Dry Density (g/cm3)2.1 2.1 2.1 #N/A #N/A
R Dry Unit Weight (pcf)131.6 132.5 131.0 #N/A #N/A
Ridgecrest
ASTM D 1557 Method A
Brown silty very fine to coarse SAND.
B-3 @ 0-5.0'
7/15/2022
7726
MAXIMUM DRY DENSITY:
Plate: MDD-1
RA
90.0
95.0
100.0
105.0
110.0
115.0
120.0
125.0
130.0
135.0
140.0
145.0
5.0 10.0 15.0 20.0 25.0 0.1 1.0 10 11
Gs=2.7 Gs=2.8 Gs=2.9
MOISTURE CONTENT (%)
DR
Y
D
E
N
S
I
T
Y
(
p
c
f
)
Client:
Work Order:
Test Date:
Sample:
Soil Classification:
Compaction Procedure:
Lab and QC by:
128.5
OPTIMUM MOISTURE CONTENT (%):9.0
A Mold diameter (in)4 4 4 4 4
B Mold height (in)4.581 4.581 4.581 4.581 4.581
C Wt. of Mold (g)4276 4276 4276 4276 4276
D Moist Soil + Mold (g)6314 6402 6417 0 0
E Soil Wt. (g)2038 2126 2141 -4276 -4276
F Volume of mold (ft3)0.0334 0.0334 0.0334 0.0334 0.0334GVolume of mold (cm3)944.99 944.99 944.99 944.99 944.99
H Moist Density (g/cm3)2.15664 2.2497593 2.265632441 -4.524916 -4.52492
M Wt. of wet soil (g)200 200 200 200 200
N Wt. of dry soiltare (g)187.4 183 180.6 176.1 175OWt. of water (g)12.6 17 19.4 23.9 25
P Moisture Content (%)6.7 9.3 10.7 #N/A #N/A
Q Dry Density (g/cm3)2.0 2.1 2.0 #N/A #N/A
R Dry Unit Weight (pcf)126.2 128.5 127.7 #N/A #N/A
MAXIMUM DRY DENSITY:
Plate: MDD-2
RA
Ridgecrest
ASTM D 1557 Method A
Brown silty very fine to coarse SAND.
B-4 @ 0-5.0'
7/15/2022
7726
90.0
95.0
100.0
105.0
110.0
115.0
120.0
125.0
130.0
135.0
140.0
145.0
5.0 10.0 15.0 20.0 25.0 0.1 1.0 10 11
Gs=2.7 Gs=2.8 Gs=2.9
MOISTURE CONTENT (%)
DR
Y
D
E
N
S
I
T
Y
(
p
c
f
)
ANAHEIM TEST LAB, INC
196 Technology Drive, Unit D
Irvine, CA 92618 Phone (949) 336-6544
DATE: 5/20/2022 GEOSOILS CONSULTANTS, INC. 6634 VALJEAN AVE. P.O. NO: Verbal
VAN NUYS, CA 91406
LAB NO: C-5989, 1-2
SPECIFICATION: CA 301
MATERIAL: Brown, Silty Sand w. Gravel
____________________________________________________________________________________________________________
Project: W.O: 7726 Client Name: Ridgecrest
ANALYTICAL REPORT
“R” VALUE
BY EXUDATION BY EXPANSION
1)B-3 @ 0-5’ 80 N/A
2)B-4 @ 0-5’ 78 N/A
RESPECTFULLY SUBMITTED
________________________________
WES BRIDGER LAB MANAGER
"R" VALUE CA 301
Client: GeoSoils Consultants, Inc.ATL No.:C 5989-1 Date:5/20/2022
Client Reference No.: 7726
Sample: B-3 @ 0-5'Soil Type:Brown, Silty Sand w. Gravel
.
TEST SPECIMEN A B C D
Compactor Air Pressure psi 350 350 350
Initial Moisture Content %2.3 2.3 2.3
Moisture at Compaction %7.4 7.9 7.6
Briquette Height in.2.43 2.54 2.51
Dry Density pcf 133.0 132.1 132.6
EXUDATION PRESSURE psi 410 157 245
EXPANSION PRESSURE psf 0 0 0
Ph at 1000 pounds psi 11 16 13
Ph at 2000 pounds psi 18 26 22
Displacement turns 4.19 4.05 4.11
"R" Value 82 76 79
CORRECTED "R" VALUE 82 76 79
Final "R" Value
BY EXUDATION:80
@ 300 psi
BY EXPANSION:N/A
TI = 5.0
5
0
10
20
30
40
50
60
70
80
90
0 100 200 300 400 500 600 700 800
"R
"
V
a
l
u
e
Exudation Pressure
"R" VALUE CA 301
Client: GeoSoils Consultants, Inc.ATL No.:C 5989-2 Date:5/20/2022
Client Reference No.: 7726
Sample: B-4 @ 0-5'Soil Type:Brown, Silty Sand w. Gravel
.
TEST SPECIMEN A B C D
Compactor Air Pressure psi 350 350 350
Initial Moisture Content %2.4 2.4 2.4
Moisture at Compaction %8.4 8.2 7.8
Briquette Height in.2.51 2.49 2.47
Dry Density pcf 128.3 129.6 130.1
EXUDATION PRESSURE psi 279 371 626
EXPANSION PRESSURE psf 0 0 0
Ph at 1000 pounds psi 13 12 10
Ph at 2000 pounds psi 23 20 16
Displacement turns 4.53 3.99 3.77
"R" Value 77 81 86
CORRECTED "R" VALUE 77 81 86
Final "R" Value
BY EXUDATION:78
@ 300 psi
BY EXPANSION:N/A
TI = 5.0
5
0
10
20
30
40
50
60
70
80
90
0 100 200 300 400 500 600 700 800
"R
"
V
a
l
u
e
Exudation Pressure
DATE:
ATTENTION: Ron Allen
TO:
SUBJECT:
COMMENTS:
James T. Keegan, MD
Corrosion and Lab Services Section Manager
TRANSMITTAL LETTER
Ridgecrest
Enclosed are the results for the subject project.
6634 Valjean Ave.
Laboratory Test Data
Van Nuys, CA 91304
July 27, 2022
Your #7726, HDR Lab #22-0716LAB
GeoSoils Consultants, Inc.
431 West Baseline Road ∙ Claremont, CA 91711
Phone: 909.962.5485 ∙ Fax: 909.626.3316 Plate CH-1
Sample ID
B-2 @ 0-5.0'
Resistivity Units
as-received ohm-cm 440,000
minimum ohm-cm 12,400
pH 5.5
Electrical
Conductivity mS/cm 0.04
Chemical Analyses
Cations
calcium Ca2+mg/kg 30
magnesium Mg2+mg/kg 16
sodium Na1+mg/kg 21
potassium K1+mg/kg 3.1
ammonium NH41+mg/kg ND
Anions
carbonate CO32-mg/kg ND
bicarbonate HCO31-mg/kg 98
fluoride F1-mg/kg 2.7
chloride Cl1-mg/kg 5.7
sulfate SO42-mg/kg 13
nitrate NO31-mg/kg 19
phosphate PO43-mg/kg ND
Other Tests
sulfide S2-qual na
Redox mV na
Minimum resistivity and pH per CTM 643, Chloride per CTM 422, Sulfate per CTM 417
Electrical conductivity in millisiemens/cm and chemical analyses were made on a 1:5 soil-to-water extract.
mg/kg = milligrams per kilogram (parts per million) of dry soil.
Redox = oxidation-reduction potential in millivolts
ND = not detected
na = not analyzed
Table 1 - Laboratory Tests on Soil Samples
Ridgecrest
Your #7726, HDR Lab #22-0716LAB
27-Jul-22
GeoSoils Consultants, Inc.
431 West Baseline Road ∙ Claremont, CA 91711
Phone: 909.962.5485 ∙ Fax: 909.626.3316 Page 2 of 2
Plate CH-1
6634 Valjean Avenue, Van Nuys, California 91406 Phone: (818) 785-2158 Fax: (818) 785-1548
MDN 23013A
July 19, 2022
W.O. 7726
(Revised July 28, 2022)
APPENDIX C
INFILTRATION TESTING RESULTS
Project Project No.7726 Date:6/15/2022
B-6 RM Drilled By:
15 SW 0.45
8
0 1 0
Trial No.
Start
Time
Stop
Time
Time
Interval,
(min.)
Initial Depth
to Water (ft.)
Final Depth
to Water
(ft.)
Change in
Water Level
(ft.)
1 3 10 12.5 2.5
2
Trial No.
Start
Time
Stop
Time
Δt, Time
Interval
(min.)
Hi, Initial
Depth to
Water (ft.)
Hf, Final
Depth to
Water (ft.)
ΔHw, Change
in Water Level
(in.)
Flow Rate
(in^3/hr.)
Wet Surface
Area (in^2)
Infiltration Rate
(in/hr)
1 3 10 12.70 32.40 15777.08 1151.08 13.71
2 3 10 12.80 33.60 16361.41 1136.00 14.40
3 3 10 12.80 33.60 16361.41 1136.00 14.40
4 3 10 12.90 34.80 16945.75 1120.92 15.12
5 3 10 12.95 35.40 17237.92 1113.38 15.48
6 3 10 12.90 34.80 16945.75 1120.92 15.12
7
8
9
10
CALCULATION:
15.24 in/hr 1
15.24 in/hr
*If the bottom of boring is capped by bentonite, the west surface area will not include the term: (π/4)(d)^2
**Reduction Factor is the sumation of Test-specefic, Site Variability and Long Term Reductions
Plate P-1
USCS Soil Classification
Test-specefic Reduction Site Variability Reduction
Greater than or Equal to 6"? (y/n)
Diameter,d (if round)=2
Long Term Reduction
Test Hole Dimensions (inches):Pipe Diameter, dp=
Tested By:2R DrillingTest Hole No.
Percolation Test Data Sheet
Percolation Rate=
North Corner of Chase Rd Arian Lane, Fontana
y
Aggregate Correction, e (Void Ratio)Depth of Boring, H (ft):
Wet Surface Area* = π*d*(H-(Hi+Hf)/2)+(π/4)(d)^2
Reduction Factor**=Average Infiltration Rate=
Falling Head Flow Rate= (ΔHw*((π/4)(dp)^2+e*(π/4)(d^2-dp^2))/(Δt)
Percolation Rate= Infiltration Rate/Reduction Factor Infiltration Rate=Falling Head Flow Rate/Wet Surface Area
12.00
12.50
13.00
13.50
14.00
14.50
15.00
15.50
16.00
16.50
17.00
0 2 4 6 8 10 12 14 16 18 20
In
f
i
l
t
r
a
t
i
o
n
R
a
t
e
(
I
n
/
h
r
)
Time (min)
Infiltration Rate versus Time
Project Project No.7726 Date:6/15/2022
B-7 RM Drilled By:
30 SW 0.45
8
0 1 0
Trial No.
Start
Time
Stop
Time
Time
Interval,
(min.)
Initial Depth
to Water (ft.)
Final Depth
to Water
(ft.)
Change in
Water Level
(ft.)
1 6 20 22.1 2.1
2
Trial No.
Start
Time
Stop
Time
Δt, Time
Interval
(min.)
Hi, Initial
Depth to
Water (ft.)
Hf, Final
Depth to
Water (ft.)
ΔHw, Change
in Water Level
(in.)
Flow Rate
(in^3/hr.)
Wet Surface
Area (in^2)
Infiltration Rate
(in/hr)
1 10 20 23.50 42.00 6135.53 2538.41 2.42
2 10 20 23.40 40.80 5960.23 2553.49 2.33
3 10 20 23.40 40.80 5960.23 2553.49 2.33
4 10 20 23.39 40.68 5942.70 2554.99 2.33
5 10 20 23.34 40.08 5855.05 2562.53 2.28
6 10 20 23.31 39.72 5802.46 2567.06 2.26
7
8
9
10
CALCULATION:
2.29 in/hr 1
2.29 in/hr
*If the bottom of boring is capped by bentonite, the west surface area will not include the term: (π/4)(d)^2
**Reduction Factor is the sumation of Test-specefic, Site Variability and Long Term Reductions
Plate P-2
Percolation Test Data Sheet
Percolation Rate=
North Corner of Chase Rd Arian Lane, Fontana
y
Aggregate Correction, e (Void Ratio)Depth of Boring, H (ft):
Wet Surface Area* = π*d*(H-(Hi+Hf)/2)+(π/4)(d)^2
Reduction Factor**=Average Infiltration Rate=
Falling Head Flow Rate= (ΔHw*((π/4)(dp)^2+e*(π/4)(d^2-dp^2))/(Δt)
Percolation Rate= Infiltration Rate/Reduction Factor Infiltration Rate=Falling Head Flow Rate/Wet Surface Area
USCS Soil Classification
Tested By:2R Drilling
Test-specefic Reduction Site Variability Reduction
Greater than or Equal to 6"? (y/n)
Diameter,d (if round)=2
Long Term Reduction
Test Hole Dimensions (inches):Pipe Diameter, dp=
Test Hole No.
2.24
2.26
2.28
2.30
2.32
2.34
2.36
2.38
2.40
2.42
2.44
0 10 20 30 40 50 60 70
In
f
i
l
t
r
a
t
i
o
n
R
a
t
e
(
I
n
/
h
r
)
Time (min)
Infiltration Rate versus Time
Project Project No. 7726 Date: 6/15/2022
RM Drilled By:
40 SW 0.45
8
0 1 0
Trial No.
Start
Time
Stop
Time
Time
Interval,
(min.)
Initial Depth
to Water (ft.)
Final Depth
to Water
(ft.)
Change in
Water Level
(ft.)
1 11:00AM 11:05AM 5 30 33.5 3.5
2 11:05AM 11:10AM 5 30 33.3 3.3
Trial No.
Start
Time
Stop
Time
Δt, Time
Interval
(min.)
Hi, Initial
Depth to
Water (ft.)
Hf, Final
Depth to
Water (ft.)
ΔHw, Change
in Water Level
(in.)
Flow Rate
(in^3/hr.)
Wet Surface
Area (in^2)
Infiltration Rate
(in/hr)
1 11:20AM 11:25AM 5 30 32.02 24.24 7082.16 2761.59 2.56
2 11:25AM 11:30AM 5 30 32.00 24.00 7012.03 2764.60 2.54
3 11:30AM 11:35AM 5 30 31.92 23.04 6731.55 2776.67 2.42
4 11:35AM 11:40AM 5 30 31.80 21.60 6310.83 2794.76 2.26
5
6
7
8
9
10
CALCULATION:
2.41 in/hr 1
2.41 in/hr
*If the bottom of boring is capped by bentonite, the west surface area will not include the term: (π/4)(d)^2
**Reduction Factor is the sumation of Test-specefic, Site Variability and Long Term Reductions
Plate P-3
Percolation Test Data Sheet
Percolation Rate=
North Corner of Chase Rd Arian Lane, Fontana
y
y
Aggregate Correction, e (Void Ratio)Depth of Boring, H (ft):
Wet Surface Area* = π*d*(H-(Hi+Hf)/2)+(π/4)(d)^2
Reduction Factor**=Average Infiltration Rate=
Falling Head Flow Rate= (ΔHw*((π/4)(dp)^2+e*(π/4)(d^2-dp^2))/(Δt)
Percolation Rate= Infiltration Rate/Reduction Factor Infiltration Rate=Falling Head Flow Rate/Wet Surface Area
USCS Soil Classification
Tested By: 2R Drilling
Test-specefic Reduction Site Variability Reduction
Greater than or Equal to 6"? (y/n)
Diameter,d (if round)= 2
Long Term Reduction
Test Hole Dimensions (inches): Pipe Diameter, dp=
Test Hole No.
0.50
1.00
1.50
2.00
2.50
3.00
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
In
f
i
l
t
r
a
t
i
o
n
R
a
t
e
(
I
n
/
h
r
)
Time (min)
Infiltration Rate versus Time
B-8/P-1
Project Project No. 7726 Date: 6/15/2022
RM Drilled By:
50 SW 0.45
8
0 1 0
Trial No.
Start
Time
Stop
Time
Time
Interval,
(min.)
Initial Depth
to Water (ft.)
Final Depth
to Water
(ft.)
Change in
Water Level
(ft.)
1 11:50AM 11:55AM 5 40 47 7
2 11:55AM 12:00PM 5 40 46.9 6.9
Trial No.
Start
Time
Stop
Time
Δt, Time
Interval
(min.)
Hi, Initial
Depth to
Water (ft.)
Hf, Final
Depth to
Water (ft.)
ΔHw, Change
in Water Level
(in.)
Flow Rate
(in^3/hr.)
Wet Surface
Area (in^2)
Infiltration Rate
(in/hr)
1 12:15PM 12:20PM 5 40 46.55 78.60 22964.41 2078.48 11.05
2 12:20PM 12:25PM 5 40 46.48 77.76 22718.99 2089.03 10.88
3 12:25PM 12:30PM 5 40 46.40 76.80 22438.51 2101.10 10.68
4
5
6
7
8
9
10
CALCULATION:
10.87 in/hr 1
10.87 in/hr
*If the bottom of boring is capped by bentonite, the west surface area will not include the term: (π/4)(d)^2
**Reduction Factor is the sumation of Test-specefic, Site Variability and Long Term Reductions
Plate P-4
Percolation Test Data Sheet
Percolation Rate=
North Corner of Chase Rd Arian Lane, Fontana
Aggregate Correction, e (Void Ratio)Depth of Boring, H (ft):
Wet Surface Area* = π*d*(H-(Hi+Hf)/2)+(π/4)(d)^2
Reduction Factor**=Average Infiltration Rate=
Falling Head Flow Rate= (ΔHw*((π/4)(dp)^2+e*(π/4)(d^2-dp^2))/(Δt)
Percolation Rate= Infiltration Rate/Reduction Factor Infiltration Rate=Falling Head Flow Rate/Wet Surface Area
USCS Soil Classification
Test-specefic Reduction Site Variability Reduction
Greater than or Equal to 6"? (y/n)
Diameter,d (if round)=
Tested By: 2R Drilling
y
y
Test Hole No.
2
Long Term Reduction
Test Hole Dimensions (inches): Pipe Diameter, dp=
9.00
9.50
10.00
10.50
11.00
11.50
12.00
0 0.5 1 1.5 2 2.5 3 3.5
In
f
i
l
t
r
a
t
i
o
n
R
a
t
e
(
I
n
/
h
r
)
Time (min)
Infiltration Rate versus Time
B-9/P-2