HomeMy WebLinkAboutTract Map 12318 Parcel 2 Preliminary Geotechnical Study Holdaway Residence7.2
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EnGEN
Preliminary Geotechnical Feasibility Study
L1625 Enterprise Circle South, Holdaway Residence
B-2,Temecula California 92590
951.296.351 • Parcel 2 of PM 12318
www engencorp.com APN: 955-040-002
Fosse Way, Temecula
FChris Smena•Tyrone Woods
Seen SWIM.oim OMerry.
Ann Smedingof/ Project Number: 4388GFS
1
February 12, 2018
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Prepared for:
Paul and Renee Holdaway
42328 Corte Villosa
Temecula, CA 92592
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1.0 EXECUTIVE SUMMARY.....................................................................................................................1
2.0 SITE/PROJECT DESCRIPTION.........................................................................................................1
2.1 Site Description:..................-........ ...........................................................................................1
2.2 Project Description:..... ........ .......--.............................. ...........................................................2
2.3 Scope of Work: ....... ...... ......... .............................................................. ............................2
2.4 Field Study:......................... ........ ................................................................-...........................2
3.0 FINDINGS....*....*........***...*.....***'*.....****...."****......*...*....*,,**...........*.......*.......... ....................**.....3
3.1 Site Review:..........................................................................-...................................................3
3.2 Subsurface Soil Profile: ..........................................................................----............................3
3.3 Transition Areas:......................................................................................-................................3
4.0 LABORATORY TESTING...................................................................................................................4
4.1 General: ......................... ............ ................................................................. ............................4
4.2 Classification:...............................-............................................................................................4
4.3 Maximum Dry Density/Optimum Moisture Content Relationship Test: .................. ..................4
4.4 Expansion Test:.............................. ............................................................. ............................4
4.5 Soluble Sulfate Test:..................................................................................................................4
4.6 pH/Minimum Resistivity .............................................................................................................4
4.7 Chloride Content........................................................................................................................4
4.8 Direct Shear Test:.............. ............................................................................................. .........4
5.0 GEOLOGY AND SEISMICITY............................................................................................................5
5.1 Geologic Setting: ................................................................................................. ...................5
5.2 Seismic Hazards:.......................-.............................................................. .......... ....................5
5.3 Seismic Design Parameters: .... ......................... ...................................... ......... ...................6
5.4 Surface Fault Rupture:.............. ................................................................................................7
5.5 Liquefaction:................... ...................................................................................... ....................7
5.6 Seismically Induced Landsliding:...............................................................................................7
5.7 Seismically Induced Flooding, Seiches: ....................................................................................7
6.0 EARTH MATERIALS..........................................................................................................................7
6.1 Colluvium/Residual Soils (Coal):................................. ...........................................................7
6.2 Sandstone Bedrock (Qpfs) ........................................................................................................7
7.0 CONCLUSIONS AND RECOMMENDATIONS ..................................................................................7
7.1 General: ............................................ ........................ ............ . ......................................... ......7
7.2 Earthwork Recommendations (All Areas)..................................................................................7
7.3 Oversize Material:.............. .......................................................................................................8
7.4 Structural Fill:............... ....................................................................................................8
7.5 Soil Expansion Potential:.......................................... ................-.............................................9
7.6 Soil Corrosive Potential: ............................................................................................................9
t8.0 SLOPE STABILITY(GENERAL):.......................................................................................................9
8.1 Cut and Fill Slopes:............... .........-.....................................................-.............................9
8.2 Foundation Design Recommendations: ....................................-..............................................9
8.3 Foundation Size:................................................... .................. ............................................... 10
8.4 Depth of Embedment:........... ...-........--.............................................. ....... .................... 10
8.5 Bearing Capacity: ........................................................... .....................................................-10
8.6 Settlement:..... .............. ..................................................................................................... .... 10
8.7 Lateral Capacity:................... ................................-...... .........-....................................... ......10
8.8 Slab-on-Grade Recommendations: .........................................................................................11
8.9 Exterior Slabs:....... ...........................................-.............................................. .......-............11
8.10 Retaining Wall Recommendations ..........................................................................................11
8.11 Earth Pressures: ............................................................................................... ......................11
8.12 Retaining Wall Design: .... ............................ ..........................................................................12
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8.13 Subdrain:..................................................................................................................................12
8A4 Backfill:.....................................................................................................................................12
8.15 Utility Trench Recommendations:................................ ............................... ...........................13
8.16 Finish Lot Drainage Recommendations: ..................................................... ...........................13
8.17 Planter Recommendations: .....................................................................................................13
8.18 Supplemental Construction Observations and Testing: ..........................................................13
9.0 PLAN REVIEW: ................................................................................................................................14
9.1 Pre-Bid Conference: ................................................................................................................14
9.2 Pre-Grading Conference:.......... ..............................................................................................14
10.0 CLOSURE.........................................................................................................................................14
tAPPENDICES:
Appendix 1 -General Technical References
1 EXHIBITS:
Exhibit 1 -Laboratory Test Results
Exhibit 2-Field Boring Log(s)
Exhibit 3-Exploratory Test Pit Log(s)
Exhibit 4-Typical Grading Detail
Exhibit 5-Surficial Slope Stability Analysis
PLATES:
Plate 1 -Geotechnical Feasibility Study Plan
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EnGEN
1 February 12, 2018
Paul and Renee Holdaway
42328 Corte Villosa
Temecula, California 92592
Subject: Geotechnical Feasibility Study—Holdaway Residence
Lot 2 of PM 12318, Fosse Way, Temecula, CA, 9259, APN: 955-040-002
Project Number: 4388GFS
References: 1. Bratene Construction and Engineering, Precise Grading Plan, Holdaway Residence,
Lot 2 of PM 12318, Fosse Way, Temecula, CA, 92591, Dated: February 12, 2018
Dear Mr. and Mrs. Holdaway,
In accordance with your request and signed authorization, a representative of this firm has visited the subject
site on Friday, January 12, 2018 to visually observe the surface conditions of the subject site, perform
subsurface exploration and testing and collect samples of representative site earth materials. Laboratory
testing was performed on these samples. Recommendations for grading operations and preliminary
foundation design are provided in the subsequent sections of this report.
1.0 EXECUTIVE SUMMARY
Feasibility for development: Based on the findings of this study it is our opinion that the
subject site is developable from a geotechnical standpoint provided the recommendations
of this report are incorporated into the design and construction of the proposed
improvement areas within the subject property.
Unsuitable Soils and Transition Zones: A portion of the supportive soils within the
proposed improvement areas consist of colluvium that is loose and porous and unsuitable
to support engineered fills or structures. A transition between native ground and
engineered fill trends beneath the building footprint which requires remedial grading.
Detailed recommendations for site grading can be found under§7.0 of this report.
Expansive Soils: Areas to receive concrete slabs will be supported on soils that have a
very low expansion potential. Minimum slab design recommendations are provided under
8.2 of this report:
2.0 SITE/PROJECT DESCRIPTION
2.1 Site Description:
The subject property is approximately 1.58-acres located east of Fosse Way, in the City of Temecula,
California. Topography across the subject site is gently sloping terrain with drainage in general to the
southwest as sheet flow. The property is vacant land and to be developed for single family residential
use. The subject site is not located in a State designated "Special Studies Zone". However, based
on the Riverside County Land Information System, it is situated in a subsidence hazard area.
41625 Enterprise Circle South, B-2,7ennecula California 92590 951..296.351 1
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Paul Holdaway-Holdaway Residence
Project Number:4388GFS
February 2018
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2.2 Project Description:
The proposed development for the subject site will be a single-family residence. It is represented that
the proposed site improvements will include the grading of a building pad area for a future residential
structure along with associated hardscape and landscape improvements (see Plate 1).
FIGURE 1 -SITE LOCATION MAP
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2.3 Scope of Work:
The scope of this study was to provide a preliminary geotechnical assessment of the surface and
subsurface conditions within the proposed development area, and to provide recommendations for
the development of the site from a geotechnical point of view. The scope included: 1) site
reconnaissance and geologic mapping, 2) subsurface exploration and field testing, 3) sampling and
laboratory testing of on-site materials, 4) engineering analysis of field and laboratory data, and 5)
preparation of this report.
2.4 Field Study:
Field reconnaissance, geologic mapping and subsurface exploration was conducted on January 12,
2018. The purpose of the subsurface exploration was to assess the underlying earth materials'
existing condition and geotechnical properties as well as the presence of historical groundwater
conditions that might affect the geotechnical integrity of the proposed improvements. Exploratory test
EnGEN Corporation
Paul Holdaway-Holdaway Residence
Project Number:4388GFS
February 2018
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pits were excavated within the proposed improvement areas of the subject site (see Plate 1). Soils
encountered consisted of silty sands (see Exploratory Logs in the Appendix). The exploratory test
pits were excavated utilizing a hand auger. Bulk samples were collected from selected depth intervals
of each Exploratory Test Pit. Representative soil samples were subsequently returned to this firm's
soils laboratory for verification of field classifications and testing. Selected samples were tested for
maximum density, USCS classification, shear strength,and expansion. In addition, soil samples were
visually inspected for evidence of corrosive properties that would dictate a formal corrosive analysis
of materials that will be in direct contact with the proposed concrete within the improvement areas.
The approximate locations of the exploratory test pits are denoted on the Geotechnical Feasibility
Study Site Plan (Plate 1).
3.0 FINDINGS
3.1 Site Review:
The subject site is an essentially rectangular shaped 1.58-acre lot, sloping in general to the southwest
at an average gradient of 5 to 10 percent. At the time of the site reconnaissance, there was a little
growth of native grasses and weeds. Based on our site study, the subject property appears to be
comprised of colluvium underlain by Pauba Formation Bedrock. The site is not located within a State
designated Alquist-Priolo Zone. However, based on the Riverside County Land Information System,
it is situated in a subsidence hazard area.
3.2 Subsurface Soil Profile:
Based on our field reconnaissance and subsurface excavations performed, the site is underlain by
the following earth materials:
TABLE 1 -EARTH MATERIALS
Earth Materials Range of Depth _ Condition-
ColluviumI Surface to approximately 2 feet Porous, loose
Pauba Formation Bedrock I From 2 to greater than 10 feet Dense to very dense
1 A mantle of Colluvium covers the natural slopes throughout the site to approximately 2 feet in depth
and overlies the Pauba Formation Bedrock (see Plate 1). The exploratory test pit logs of earth
materials encountered during the subsurface exploration are included in Appendix C. Further
discussion of the on-site earth material is presented in § 4.3 of this report.
3.3 Transition Areas:
A transition between cut and fill areas of the pad are identified on the Referenced No. 1 Grading Plan.
To guard against potential differential settlement, the future structure should not straddle a transition
area between cut and fill on the subject site without remedial grading unless other recommendations
are made in writing.
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Paul Holdaway—Holdaway Residence
Project Number:4388GF5
February 2018
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4.0 LABORATORY TESTING
4A General:
The results of laboratory tests performed on samples of earth material obtained during the site visit
are presented in the attached Appendix. Following is a listing and brief explanation of the laboratory
tests performed.
4.2 Classification:
The field classification of soil materials encountered during our site visit were verified in the laboratory
in general accordance with the Unified Soils Classification System, ASTM D 2488-00, Standard
Practice for Determination and Identification of Soils (Visual-Manual Procedures).
4.3 Maximum Dry Density/Optimum Moisture Content Relationship Test:
Maximum dry density/optimum moisture content relationship determinations were performed on
samples of near-surface earth material in general accordance with ASTM 1557-12 procedures using
a 4.0-inch diameter mold. Samples were prepared at various moisture contents and compacted in
five (5) layers using a 10-pound weight dropping 18-inches and with 25 blows per layer.
4.4 Expansion Test:
Laboratory expansion tests were performed on samples of near-surface earth material in general
accordance with CBC 18-2. In this testing procedure, a remolded sample is compacted in two (2)
layers in a 4.0-inch diameter mold to a total compacted thickness of approximately 1.0-inch by using
a 5.5-pound weight dropping 12-inches and with 15 blows per layer. The sample should be
compacted at a saturation between 49 and 51 percent. After remolding, the sample is Confined under
a pressure of 144 pounds per square foot (psf) and allowed to soak for 24 hours. The resulting
volume change due to the increase in moisture content within the sample is recorded and the
Expansion Index (EI) calculated.
4.5 Soluble Sulfate Test:
Samples of the near—surface earth materials were obtained for soluble sulfate testing for the site.
The concentration of soluble sulfates was determined in the general conformance with California Test
Method 417 procedures.
4.6 pH/Minimum Resistivity
Sample(s) of near surface soils were tested for pH and minimum resistivity in general accordance to
CTM 643.
4.7 Chloride Content
Sample(s)of near surface soils were tested for chloride content in general conformance to CTM 422.
4.8 Direct Shear Test:
Direct shear tests were performed on select samples of near-surface earth material in general
accordance with ASTM D 3080-03 procedures. The shear machine is of the constant strain type.
The shear machine is designed to receive a 1.0-inch high, 2.42-inch diameter ring sample.
Specimens from the sample were sheared at various pressures normal to the face of the specimens.
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Paul Holdaway—Holdaway Residence
Project Number:4388GFS
February 2018
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The specimens were tested in a submerged condition. The maximum shear stresses were plotted
versus the normal confining stresses to determine the shear strength (cohesion and angle of internal
friction).
Excavation Characteristics: Excavation in the engineered fill should be moderate to moderately
difficult. Based on our experience on similar projects near the subject site, the bedrock is expected
to be moderate to difficult ripping within the upper 6 feet.
5.0 GEOLOGY AND SEISMICITY
5.1 Geologic Setting:
The site is located in the Northern Peninsular Range on the southern sector of the structural unit
known as the Perris Block. The Perris Block is bounded on the northeast by the San Jacinto Fault
Zone, on the southwest by the Elsinore Fault Zone, and on the north by the Cucamonga Fault Zone.
The southern boundary of the Perris Block is not as distinct, but is believed to coincide with a complex
group of faults trending southeast from the Murrieta,California area(Kennedy, 1977). The Peninsular
Range is characterized by large Mesozoic age intrusive rock masses flanked by volcanic,
metasedimentary, and sedimentary rocks. Various thicknesses of colluvial/alluvial sediments derived
from the erosion of the elevated portions of the region fill the low-lying areas. The earth materials
encountered on the subject site on the subject site are described in more detail in subsequent
sections of this report
5.2 Seismic Hazards:
Because the proposed development is located in tectonically active southern California, it will likely
experience some effects from earthquakes. The type or severity of seismic hazards affecting the site
is mainly dependent upon the distance to the causative fault, the intensity of the seismic event, and
the soil characteristics. The seismic hazard may be primary, such as surface rupture and/or ground
shaking, or secondary, such as liquefaction or dynamic settlement. The following is a site-specific
discussion about ground motion parameters, earthquake induced settlement hazards, and
liquefaction. The purpose of this analysis is to identify potential seismic hazards and propose
mitigations, if necessary, to an acceptable level of risk. The following seismic hazards discussion is
guided by CBC (2016).
EnGEN Corporation
Paul Holdaway—Holdaway Residence
Project Number:4388GFS
February 2018
FIGURE 2
Page 6
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5.3 Seismic Design Parameters:
The 2016 California Building Code (CBC) seismic design parameters for the subject site are as
follows:
Descri"lion 'a- Des( n.Parameters
Site Latitude: 33.507377eN
Site Longitude: 117.106237OW
Site Class: D
Spectral Response(Short): 0.2 sec -Ss: 1.856
Spectral Response- 1-Second): 1.0 sec -Sr. 0.746
Short Period Site Coefficient: Fa: 1.0
1-Second Period Site Coefficient: Fv: 1.5
Adjusted Spectral Response: Short Period -0.2 sec-Sms: 1.856
Adjusted Spectral Response: One Sec -SmY. 1.119
Design Spectral Response: '.. Short Period 0.2 sec-Sda: 1.237
Design Spectral Response: One Sec 1.0 sec-Sdt 0.746
EnGEN Corporation
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Paul Holdaway—Holdaway Residence
Project Number:4388GFS
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5.4 Surface Fault Rupture:
t
No known active faults exist on the subject site. Accordingly, the potential for fault surface rupture on
the site is considered unlikely.
5.5 Liquefaction:
Based on the nature and density of the Pauba Formation bedrock, and the assumed depth to
groundwater the potential for hazards associated with liquefaction are considered low.
5.6 Seismically Induced Landsliding:
Due to the density and coarse-grained nature of the engineered fill and underlying Pauba Formation
bedrock at the subject site, the probability of seismically induced landsliding is considered low.
5.7 Seismically Induced Flooding, Seiches:
Due to the lack of a large body of water located above the subject site, the possibility of seismically
induced flooding or seiches is considered low. Due to the large distance of the project site to the
Pacific Ocean, the possibility for seismically induced tsunamis to impact the site is considered nil.
6.0 EARTH MATERIALS
6A Colluvium/Residual Soils (CQal):
Based on the subsurface exploration, colluvial material and residual soils cover the majority of the
site and is underlain by Pauba Formation Bedrock (see Plate 1).
6.2 Sandstone Bedrock(Qpfs)
The subject site has been mapped within the geologic bedrock formation commonly referred to as
the Pauba Formation. The Pauba Formation Bedrock is a sandstone formation comprised of silty
and clayey sands to gravelly clean sands that is partially weathered near the surface and becomes
dense to very dense at deeper depths.
7.0 CONCLUSIONS AND RECOMMENDATIONS
7.1 General:
Based on the findings of this study it is our opinion that the subject site is developable from a
geotechnical standpoint provided the recommendations of this report are incorporated into the design
and construction of the proposed improvement areas within the subject property.
7.2 Earthwork Recommendations (All Areas)
All vegetation should be removed from areas to be graded and not used In fills.
1 All man-made debris material, if any, should be removed from the site and not used in fills.
Based on a review of the Referenced No. 1 grading plan there will be a transition between cut
and fill within the footprint of the proposed structure (see Plate 1). As a result, over-excavation
is required in the building area extending 5' outside of the footing and should extend '/2 the
depth of engineered fill or a minimum of 36" (whichever is greater). Removals should expose
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Paul Holdaway—Holdaway Residence
Project Number:4388GFS
February 2018
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competent unweathered bedrock in structural and hardscape areas. The material generated
during removals should be cleared of any debris, and may then be placed as engineered fill.
tDeeper removals may be required depending upon exposed conditions encountered and
foundation dimensions of the proposed structure.
All exposed removal and overexcavation bottoms should be inspected by the Geotechnical
Engineer's representative prior to placement of any fill. Bottoms should be probed to verify
competency and a natural density of 85 percent or greater.
The approved exposed bottoms of all removal areas should be scarified 12-inches, brought to
near optimum moisture content, and compacted to a minimum of 90 percent relative
compaction before placement of fill. Structural fill should be compacted to a minimum of 90
percent relative compaction. Maximum dry density and optimum moisture content for
compacted materials should be determined according to ASTM D 1557-12 procedures.
Any fill or cut slopes should be constructed at slope ratios no steeper than 2:1 (horizontal to
vertical).
7.3 Oversize Material:
Oversize material is defined as rock, or other irreducible material with a maximum dimension greater
than 12-inches. Oversize material shall not be buried or placed in fill unless location, materials, and
placement methods are specifically accepted by the Project Geotechnical Engineer. Placement
operations shall be such that nesting of oversize material does not occur, and such that oversize
material is completely surrounded by compacted fill (windrow). Alternative methods, such as water
jetting or wheel rolling with a backhoe may be required to achieve compaction in the fill materials
t immediately adjacent to the windrow. Oversize material shall not be placed within ten (10) vertical
feet of finish grade, within fifteen (15) lateral feet of a finished slope face, or within two (2) feet of
future utilities.
7.4 Structural Fill:
All fill material, whether on-site material or import, should be accepted by the Project Geotechnical
Engineer and/or his representative before placement. All fill should be free from vegetation, organic
material, and other debris. Import fill should be no more expansive than the existing on-site material,
unless approved by the Project Geotechnical Engineer. Approved fill material should be placed in
horizontal lifts not exceeding 6.0 to 8.0-inches in thickness, and watered or aerated to obtain near-
optimum moisture content (within 2.0 percent of optimum). Each lift should be spread evenly and
should be thoroughly mixed to ensure uniformity of soil moisture. Structural fill should meet a
1
minimum relative compaction of 90 percent of maximum dry density based upon ASTM D 1557-12
procedures. Moisture content of fill materials should not vary more than 2.0 percent of optimum,
unless approved by the Project Geotechnical Engineer.
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Project Number:4388GFS
February 2018
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7.5 Soil Expansion Potential:
Preliminary Expansion Index testing was performed, yielding an El of 0-20<. This is classified as a
Very Low expansion potential. Import soils or soils used near finish grade may have a different El.
Final foundation design parameters should be based on El testing of near-surface soils and be
performed at the conclusion of rough grading. Those results should be forwarded and incorporated
into the final design by the Project Structural Engineer.
7.6 Soil Corrosive Potential:
The highest sulfate (SO4) concentration measured was 20 ppm (mg/kg). Generally, sulfate
concentrations greater than 1,500 ppm are considered to be corrosive to metals and concrete. The
highest chloride concentrations were 50 ppm. Generally, chloride concentrations greater than 500
ppm are considered to be corrosive to metals and concrete. The soil pH level was 6.4. Generally, a
pH level less than 5.5 is considered to be corrosive to metal and concrete. Based on corrosion test
results, Type II Concrete may be used for foundation design.
Table 3-Summary of Laboratory Corrosion Test Results
Minimum.SulfateSampleSampleDeptiiin Chloride
Resistivity pH ContentLocationNo. ft) ohm-cm) m Content(ppm)
B-2 A2 0-2' 3,000 6.4 20 50
The client may wish to have a corrosion engineer review the test results for design consideration if
the concentration levels presented above are such that a more detailed review is deemed necessary.
EnGEN Can provide this service upon request.
8.0 SLOPE STABILITY(GENERAL):
8.1 Cut and Fill Slopes:
It is our opinion that the proposed Slopes as inclined at a ratio of 2:1 or flatter will possess gross and
surficial stability in excess of generally accepted minimum engineering criteria (Factor of Safety at
least 1.5) and would be suitable for their intended purpose, provided that proper slope maintenance
procedures are maintained. These procedures include but are not limited to installation and
maintenance of drainage devices and planting of slope faces to protect from erosion in accordance
with County standards.
8.2 Foundation Design Recommendations:
Foundations for the proposed structures may consist of conventional column footings and continuous
wall footings founded either on Engineered Fill or undisturbed bedrock but not a combination of both.
The recommendations presented in the subsequent paragraphs for foundation design and
construction are based on geotechnical characteristics and upon a very low expansion potential for
the supporting soils and should not preclude more restrictive structural requirements. The Structural
Engineer for the project should determine the actual footing width and depth in accordance with the
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latest edition of the California Building Code to resist design vertical, horizontal, and uplift forces and
should either verify oramend the design based on final expansion testing at the completion of grading,
if necessary.
8.3 Foundation Size:
Continuous footings should have a minimum width of 12-inches. Continuous footings should be
continuously reinforced with a minimum of one (1) No. 4 steel reinforcing bars located near the tap
and one(1) No.4 steel reinforcing bars located near the bottom of the footings to minimize the effects
of slight differential movements which may occur due to minor variations in the engineering
characteristics or seasonal moisture change in the supporting soils. Column footings should have a
minimum width of 18-inches by 18-inches and be suitably reinforced, based on structural
requirements. A grade beam, founded at the same depths and reinforced the same as the adjacent
footings, should be provided across doorway and garage entrances.
8.4 Depth of Embedment:
Exterior and interior footings founded in native soils should extend to a minimum depth of 12-inches
for single story structures and 18-inches for two story structures below lowest adjacent finish grade.
8.5 Bearing Capacity:
Provided the recommendations for site earthwork, minimum footing width, and minimum depth of
embedment for footings are incorporated into the project design and construction, the allowable
bearing value for design of continuous and column footings, for the residential structure for the total
dead plus frequently-applied live loads, is 1,500 psf for footings in competent engineered fill and 2,500
psf when founded on unweathered bedrock. The allowable bearing value has a Factor of Safety of
at least 3.0 and may be increased by 33.3 percent for short durations of live and/or dynamic loading
such as wind or seismic forces.
8.6 Settlement:
Footings designed according to the recommended bearing values and the maximum assumed wall
and column loads are not expected to exceed a maximum settlement of 0.75-inch or a differential
settlement of 0.50-inch over a distance of 40-feet in compacted fill material under static load
conditions.
8.7 Lateral Capacity:
Additional foundation design parameters for the residence based on compacted fill for resistance to
static lateral forces, are as follows:
Allowable Lateral Pressure(Equivalent Fluid Pressure Passive Case
Unweathered Pauba Formation Bedrock 300 pcf
Engineered Fill 150 pcf
Allowable Coeffiai ifit of Friction
Unweathered Pauba Formation Bedrock 0.35
En ineered Fill 0.35
Lateral load resistance may be developed by a combination of friction acting on the base of
foundations and slabs and passive earth pressure developed on the sides of the footings and stem
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walls below grade when in contact with undisturbed, native competent material. The above values
are allowable design values and may be used in combination without reduction in evaluating the
resistance to lateral loads. The allowable values may be increased by 33.3 percent for short durations
of live and/or dynamic loading, such as wind or seismic forces. For the calculation of passive earth
resistance, the upper 1.0-foot of material should be neglected unless confined by a concrete slab or
pavement. The maximum recommended allowable passive pressure is 5.0 times the recommended
design value.
8.8 Slab-on-Grade Recommendations:
The recommendations for concrete slabs, both interior and exterior, excluding PCC pavement, are
based upon the anticipated building usage and upon a very low expansion potential for the supporting
material as determined by Chapter 18 of the California Building Code. Concrete slabs should be
designed to minimize cracking as a result of shrinkage. Joints (isolation, contraction, and
construction) should be placed in accordance with the American Concrete Institute (ACI) guidelines.
Special precautions should be taken during placement and curing of all concrete slabs. Excessive
slump(high water/cement ratio)of the concrete and/or improper curing procedures used during either
hot or cold weather conditions could result in excessive shrinkage, cracking, or curling in the slabs.
It is recommended that all concrete proportioning, placement,and curing be performed in accordance
with ACI recommendations and procedures. Slab-on-grade reinforcement and thickness should be
provided by the structural engineer based on structural considerations, but as a minimum, it is
recommended that concrete floor slabs be at least 4-inches in actual thickness and reinforced with at
least No. 3 reinforcing bars placed 24-inches on center, both ways, placed at mid-height of the slab
cross-section.
8.9 Exterior Slabs:
All exterior concrete slabs cast on finish subgrade(patios, sidewalks, etc., with the exception of PCC
pavement) should be a minimum of 4-inches nominal in thickness. Reinforcing in the slabs and the
use of a compacted sand or gravel base beneath the slabs should be according to the current local
standards. Subgrade soils should be moisture conditioned to at least optimum moisture content to a
depth of 12-inches immediately before placing the concrete.
8.10 Retaining Wall Recommendations
8.11 Earth Pressures:
Retaining walls backfilled with non-expansive granular soil (EI=O) or very low expansive potential
materials (Expansion Index of 20 or less) within a zone extending upward and away from the heel of
the footing at a slope of 0.5:1 (horizontal to vertical) or flatter can be designed to resist the following
static lateral sail pressures:
Condition Levei'Backfilt.- 2:1'Slope Seismic
Active 30 pcf 45 pcf Ku=0.2
At Rest 60 pcf
EnGEN Corporation
Paul Holdaway—Holdaway Residence
Project Number:4388GFS
February 2018
Page 12
Further expansion testing of potential backfill material should be performed at the time of retaining
wall construction to determine suitability. Walls that are free to deflect 0.01 radian at the top may be
designed for the above-recommended active condition. Walls that need to be restricted from this
amount of movement should be assumed rigid and designed for the at-rest condition. The above
values assume well-drained backfill and no buildup of hydrostatic pressure. Surcharge loads, dead
and/or live, acting on the backfill behind the wall should also be considered in the design.
8.12 Retaining Wall Design:
Retaining wall footings should be founded to the same depths into firm, competent, undisturbed,
engineered fill or unweathered bedrock as standard foundations and may be designed for an
allowable bearing value of 1,500 psf and 2,500 psf respectively (as long as the resultant force is
located in the middle one-third of the footing), and with an allowable static lateral bearing pressure of
150 psf/ft in compacted engineered fill or 300 psf/ft in unweathered bedrock and allowable sliding
resistance coefficient of friction of 0.35. When using the allowable lateral pressure and allowable
sliding resistance, a Factor of Safety of 1.5 should be achieved.
8.13 Subdrain:
A subdrain system should be constructed behind and at the base of retaining walls equal to or in
excess of 4-feet in height to allow drainage and to prevent the buildup of excessive hydrostatic
pressures.Gravel galleries and/orfilter rock, if not properly designed and graded for the on-site and/or
import materials, should be enclosed in a geotextile fabric such as Mirafi 140N, Supac 4NP, or a
suitable substitute in order to prevent infiltration of fines and clogging of the system. The perforated
pipes should be at least 4.0-inches in diameter. Pipe perforations should be placed downward.
Gravel filters should have volume of at least 1.0 cubic foot per lineal foot of pipe. For retaining walls
with an overall height of less than 4-feet, subdrains may include weep holes with a continuous gravel
gallery, perforated pipe surrounded by filter rock, or some other approved system. Subdrains should
maintain a positive flow gradient and have outlets that drain in a non-erosive manner.
8.14 Backfill:
Backfill directly behind retaining walls (if backfill width is less than 3 feet) may consist of 0.5 to 0.75-
inch diameter, rounded to subrounded gravel enclosed in a geotextile fabric such as Mirafi 140N,
Supac 4NP, or a suitable substitute or a clean sand (Sand Equivalent Value greater than 50) water
jetted into place to obtain proper compaction. If waterjetting is used, the subdrain system should be
in place. Even if water jetting is used, the sand should be densified to a minimum of 90 percent
relative compaction. If the specified density is not obtained by waterjetting, mechanical methods will
be required. If other types of soil or gravel are used for backfill, mechanical compaction methods will
be required to obtain a relative compaction of at least 90 percent of maximum dry density. Backfill
directly behind retaining walls should not be compacted by wheel, track or other rolling by heavy
construction equipment unless the wall is designed for the surcharge loading. If gravel, clean sand
or other imported backfill is used behind retaining walls, the upper 18-inches of backfill in unpaved
EnGEN Corporation
Paul Holdaway—Holdaway Residence
Project Number:4388GFS
February 2018
Page 13
areas should consist of typical on-site material compacted to a minimum of 90 percent relative
compaction in order to prevent the influx of surface runoff into the granular backfill and into the
subdrain system. Maximum dry density and optimum moisture content for backfill materials should
be determined in accordance with ASTM D 1557-12 procedures.
8.15 Utility Trench Recommendations:
Utility trenches within the zone of influence of foundations or under building floor slabs, hardscape,
and/or pavement areas should be backfilled with properly compacted soil. It is recommended that all
utility trenches excavated to depths of 5.0-feet or deeper be cut back to an inclination not steeper
than 1:1 (horizontal to vertical)or be adequately shored during construction. Where interior or exterior
utility trenches are proposed parallel and/or perpendicular to any building footing, the bottom of the
trench should not be located below a 1:1 plane projected downward from the outside bottom edge of
the adjacent footing unless the utility lines are designed for the footing surcharge loads. Backfill
material should be placed in a liftthickness appropriate for the type of backfill material and compaction
equipment used. Backfill material should be compacted to a minimum of 90 percent relative
compaction by mechanical means.Jetting of the backfill material will not be considered a satisfactory
method for compaction. Maximum dry density and optimum moisture content for backfill material
ishould be determined according to ASTM D 1557-12 procedures.
8.16 Finish Lot Drainage Recommendations:
Finish lot surface gradients in unpaved areas should be provided next to tops of slopes and buildings
to direct surface water away from foundations and slabs and from flowing over the tops of slopes.
The surface water should be directed toward suitable drainage facilities. Ponding of surface water
should not be allowed next to structures or on pavements. In unpaved areas, a minimum positive
gradient of 2.0 percent away from the structures and tops of slopes for a minimum distance of 10.0-
feet and a minimum of 1.0 percent pad drainage off the property in a non-erosive manner should be
provided.
8.17 Planter Recommendations:
Planters around the perimeter of the structure should be designed with proper surface slope to ensure
that adequate drainage is maintained and minimal irrigation water is allowed to percolate into the soils
underlying the building.
8.18 Supplemental Construction Observations and Testing:
Any subsequent grading for development of the subject property should be performed under
engineering observation and testing performed by EnGEN Corporation. Subsequent grading
Aincludes, but is not limited to, any additional over-excavation of cut and/or cut/fill transitions, fill
placement, and excavation of temporary and permanent cut and fill slopes. In addition, EnGEN
Corporation should observe all foundation excavations. Observations should be made prior to
installation of concrete forms and/or reinforcing steel to verify and/or modify, if necessary, the
conclusions and recommendations in this report. Observations of over-excavation cuts, fill
EnGEN Corporation
Paul Holdaway-Holdaway Residence
Project Number:4388GFS
February 2018
Page 14
placement, finish grading, utility or other trench backfill, pavement subgrade and base course,
retaining wall backfill, slab pre-saturation, or other earthwork completed for the development of
subject property should be performed by EnGEN Corporation. If any of the observations and testing
to verify site geotechnical conditions are not performed by EnGEN Corporation, liability forthe safety
and performance of the development is limited to the actual portions of the project observed and/or
tested by EnGEN Corporation.
t9.0 PLAN REVIEW:
Subsequent to formulation of final plans and specifications for the project but before bids for
construction are requested, grading and foundation plans for the proposed development should be
reviewed by EnGEN Corporation to verify compatibility with site geotechnical conditions and
conformance with the recommendations contained in this report. If EnGEN Corporation is not
accorded the opportunity to make the recommended review, we will assume no responsibility for
misinterpretation of the recommendations presented in this report.
9.1 Pre-Bid Conference:
It is recommended that a pre-bid conference be held with the owner or an authorized representative,
the Project Architect, the Project Civil Engineer, the Project Geotechnical Engineer and the proposed
contractors present. This conference will provide continuity in the bidding process and clarify
questions relative to the supplemental grading and construction requirements of the project.
9.2 Pre-Grading Conference:
Before the start of any grading, a conference should be held with the owner or an authorized
representative, the contractor, the Project Architect, the Project Civil Engineer, and the Project
Geotechnical Engineer present. The purpose of this meeting should be to clarify questions relating
to the intent of the supplemental grading recommendations and to verify that the project specifications
comply with the recommendations of this geotechnical engineering report. Any special grading
procedures and/or difficulties proposed by the contractor can also be discussed at that time.
10.0 CLOSURE
This report has been prepared for use by the parties or project named or described in this document.
It may or may not contain sufficient information for other parties or purposes. In the event that
changes in the assumed nature, design, or location of the proposed structure and/or project as
described in this report, are planned, the conclusions and recommendations contained in this report
will not be considered valid unless the changes are reviewed and the conclusions and
recommendations of this report are modified or verified in writing. This study was conducted in
general accordance with the applicable standards of our profession and the accepted soil and
foundation engineering principles and practices at the time this report was prepared. No other
warranty, implied or expressed beyond the representations of this report, is made. Although every
EnGEN Corporation
1
Paul Holdaway-Holdaway Residence
Project Number:4388GFS
February 2018
Page 15
the site, limitations exist with respect to the knowledge of unknown regional or localized off-site
conditions that may have an impact at the site. The recommendations presented in this report are
valid as of the date of the report. However, changes in the conditions of a property can occur with the
passage of time, whether they are due to natural processes or to the works of man on this and/or
adjacent properties. If conditions are observed or information becomes available during the design
and construction process that are not reflected in this report, EnGEN Corporation should be notified
so that supplemental evaluations can be performed, and the conclusions and recommendations
presented in this report can be modified or verified in writing. Changes in applicable or appropriate
standards of care or practice occur, whether they result from legislation or the broadening of
knowledge and experience. Accordingly, the conclusions and recommendations presented in this
report may be invalidated,wholly or in part, by changes outside of the control of EnGEN Corporation
which occur in the future.
Thank you for the opportunity to provide our services. Often, because of design and construction details
which occur on a project, questions arise concerning the geotechnical conditions on the site. If we can be of
further service or should you have questions regarding this report, please do not hesitate to contact this office
at your convenience. Because of our involvement in the project to date, we would be pleased to discuss
engineering testing and observation services that may be applicable on the project.
Respectfully submitted,
E C ration
H.a imb rincipal sbjorn atene, nci I
Project Mana r, R PA 467 GE 162
Q OFESSjON1QUOpFNBRgr `FZHWB/OB:pm R1 F2 G
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Distribution: (2) Addressee w No. 162 Mcc
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OF CAOF
EnGEN Corporation
1 Paul Holdaway—Holdaway Residence
Project Number:4388GFS
February 2018
Exhibits
Exhibit 1 - Laboratory Test Results
1
1
EnGEN Corporation
1
MAXIMUM DENSITY - OPTIMUM MOISTURE REPORT
132
131
o
130
NN
a
Nca
C
129
128
ZAV for
Sp.G. _
127
2.56
5 6 7 8 9 10 11
Water content, %
Test specification: ASTM D 1557-00 Method A Modified
Elev/Classification Nat.
G
Depth USCS AASHTO Moist.
Sp. .LL PI
4 No.200
0-2' SM 2.5
TEST RESULTS MATERIAL DESCRIPTION
Maximum dry density = 130.3 pcf Silty Sand,Brown
Optimum moisture = 7.9 %
Project No. 4388-GFS Client: Paul Holdaway Remarks:
Project: Holdaway Residence SAMPLE#A-1
SAMPLED BY JP
o Location: TP2 @ 0-2'Sample Number: A-1 SAMPLED ON 1/]2/18
EnGEN Corporation Figure
Tested By: PB Checked By: PB
CBC Laboratory Expansion Test Results
Job Number: 4388GF5
Job Name: Holdaway Residence
Location: Fosse Way
Date: 01/17/18
Sample Source: TP1 @ 0-2'
Sampled by: JP
Lab Technician: PB
Sample Descr: Silty sand, brown
Sample#: A-1
Wet Compacted Wt.: 615.2
Ring Wt.: 196.8 Dial Change Time
Net Wet Wt.: 418.4 Reading 1: 0.100 N/A 12:00 PM
Wet Density: 126.4 Reading 2: 0.100 0.000 12:15 PM
Wet Soil: 250.2 Reading 3: 0.100 0.000 12:30 PM
Dry Soil: 228.7 Reading 4: 0.100 0.000 18-Jan
Initial Moisture (%): 9.4%
Initial Dry Density: 115.5
Saturation: 55.3%
Final Wt. & Ring Wt.: 629.8
Net Final Wt.: 433.0
Dry Wt.: 382.4
Loss: 50.6 Expansion Index: 0
Net Dry Wt.: 379.1
Final Density: 114.5 Adjusted Index:2.1
Saturated Moisture: 13.3% CBC 18-2)
EnGEN Corporation
41625 Enterprise Circle South, B-2
Temecula, California 92590
ph.951.296.3511 *fax 951.296.9045
email: engen@engencorp.com-www.engencorp.com
1
3000
2000
I
y N
6 d
NNN
1000
1
Fail. Ult.
C, psf 238 183
deg 38.9 35.909Tan0.61 0.72
0 1000 2000 3000 4000 5000 6000
Normal Stress, psf
3000 1 1 1 1 1 1 111 1 1 1 1Sample No. 1 2 3
Water Content, % 9.0 9.0 9.0
2500 Dry Density, pcf 122.9 80.8 121.5
3
Saturation, % 76.9 23.6 73.3
2000
S Void Ratio 0.3008 0.9782 0.3155
n Diameter, in. 2.42 2.42 2.42
w 2 Hei ht in. 1.00 1.00 1.00
1500 Water Content, % 16.1 15.8 15.5
Dry Density, pcf 122.9 80.8 121.5
U) 1000 W Saturation, % 136.6 41.4 125.8
Void Ratio 0.3008 0.9782 0.3155
Diameter, in. 2.42 2.42 2.42
500 Hei ht in. 1.00 1.00 1.00
Normal Stress, psf 1000 2000 3000EF
0 Fail. Stress, psf 1047 1849 2661
0 0.05 0.1 0.15 0.2 Displacement, in. 0.06 0.07 0.08
Horiz. Displacement, in. Ult. Stress, psf 880 1682 2328
Displacement, in. 0.14 0.17 0.15
Strain rate, in./min. 0.100 0.100 0.100
Sample Type: REMOLD Client: Paul Holdaway
Description: Silty Sand, Brown
Project: Holdaway Residence
Specific Gravity=2.56 Location: TP2 @ 0-2'
Remarks: SAMPLE#A-1 Sample Number: A-1 Depth: 0-2'
SAMPLED BY JP Proj. No.: 4388-GFS Date Sampled: 1-12-18
SAMPLED ON 1-11-18 DIRECT SHEAR TEST REPORT
Figure EnGEN Cor oration
Tested By: JP Checked By: JP
1
MAXIMUM DENSITY - OPTIMUM MOISTURE REPORT
131
1
130
I
129
Ud
NCNU
128
127
1
ZAV for
2.60
126
2.60
5 6 7 8 9 10 11
Water content, %
Test specification: ASTM D 1557-00 Method A Modified
Elev/Classification Nat.
Depth USCS AASHTO Moist.
Sp.G.LL PI
94 No.200
2.5-3'SM 5.1
TEST RESULTS MATERIAL DESCRIPTION
Maximum dry density = 129.8 pcf Silty Sand, Brown
Optimum moisture= 8.3
Project No. 4388-GFS Client: Paul Holdaway Remarks:
Project: Holdaway Residence SAMPLE#A-1
SAMPLED BY JP
o Location: TP2 r@i 2.5-3'Sample Number:A-2 SAMPLED ON 1-I 1-18
EnGEN Corporation Figure
Tested By: IC Checked By: PB
CBC Laboratory Expansion Test Results
Job Number: 4388GFS
Job Name: Holdaway Residence
Location: Fosse Way
Date: 01/29/18
Sample Source: TP2 @ 2.5-3'
Sampled by: 1P
Lab Technician: JP
Sample Descr: Silty sand, brown
Sample#: A-2
Wet Compacted Wt.: 618.8
Ring Wt.: 194.3 Dial Change Time
Net Wet Wt.: 424.5 Reading 1: 0.100 N/A 12:00 PM
Wet Density: 128.2 Reading 2: 0.100 0.000 12:15 PM
Wet Soil: 242.4 Reading 3: 0.099 -0.001 12:30 PM
Dry Soil: 222.3 Reading 4: 0.098 -0.002 30-Jan
Initial Moisture 9.0%
Initial Dry Density: 117.6
Saturation: 56.4%
Final Wt. & Ring WL: 634.8
Net Final Wt.: 440.5
Dry Wt.: 389.3
Loss: 51.2 Expansion Index: 0
Net Dry Wt.: 386.1
Final Density: 116.6 Adjusted Index:2.5
Saturated Moisture: 13.3% CBC 18-2)
1
EnGEN Corporation
41625 Enterprise Circle South, B-2
Temecula, California 92590
ph.951.296.3511 " fax 951.296.9045
email: engen@engencorp.com-www.engencorp.com
1
3000 Fail. Ult.
C, psf 290 ill
deg 36.8 36.4
Tan 0.75 0.74
1 z000
a
co
u NN N
t 1000
5l
i
I
0 1000 2000 3000 4000 5000 6000
Normal Stress, psf
3000 Sample No. 1 2 3
k Water Content, % 9.3 9.5 9.5
2500 Dry Density, pcf 122.2 122.1 121.4
3 70Saturation, % 73.9 74.9 73.1
2000 Void Ratio 0.3280 0.3290 0.3373
N
Diameter, in. 2.42 2.42 2.42a
N
2 Height, in. 1.00 1.00 1.00aNi
U) 1500 -Water Content, % 14.9 15.7 14.5
Dry Density, pcf 122.2 122.1 121.4
En 1000 Saturation, % 118.4 123.8 111.4
1 C Void Ratio 0.3280 0.3290 0.3373
Diameter, in. 2.42 2.42 2.42
500
I Height, in. 1.00 1.00 1.00
Normal Stress, psf 1000 2000 3000
0 Fail. Stress, psf 1056 1751 2553
0 0.1 0.2 0.3 0.4 Displacement, in. 0.07 0.10 0.08
Horiz. Displacement, in. Ult. Stress, psf 831 1624 2308
Displacement, in. 0.19 0.22 0.22
Strain rate, in./min. 0.100 0.100 0.100
Sample Type: REMOLD Client: Paul Holdaway
Description: Silty Sand, Brown
Project: Holdaway Residence
Specific Gravity=2.6 Location: TP2 @ 2.5-3'
Remarks: SAMPLE#A-2 Sample Number: A-2 Depth: 2.5-3'
SAMPLED BY JP Proj. No.: 4388-GFS Date Sampled: 1-12-18
SAMPLED ON 1-12-18 DIRECT SHEAR TEST REPORT
Figure EnGEN Corporation
Tested By: JP Checked By: JP
1
S®iIC®r
CORROSION&THERMAL SCIENCES
41765 Hawthorn Street Murrieta,CA 92562
ph(951)894-2682 • fx(951)894-2683
Work Order No.: 18A2332
Client: EnGEN Corporation
Project No.: 4388-GFS
tProject Name: Holdaway / Fosse Way
Report Date: February 12, 2018
Laboratory Test(s) Results Summary
The subject soil sample was processed in accordance with California Test Method CTM 643
and tested for pH / Minimum Resistivity (CTM 643), Sulfate Content (CTM 417) and Chloride
Content (CTM 422). The test results follow:
Minimum Sulfate Sulfate Chloride
Sample Identification pH Resistivity Content Content Content
ohm-cm) (mg/kg) (% by wgt) (ppm)
Sample TP-2 @ 0-2 ft 6.4 3,000 20 0.002 50
ND=No Detection
We appreciate the opportunity to serve you. Please do not hesitate to contact us with any
questions or clarifications regarding these results or procedures.
Ahmet K. Kaya, Laboratory Manager
Form No. 40-PR
www.soilcor.com Rev. 01/17
Paul Holdaway—Holdaway Residence
Project Number:4388GFS
February 2018
Plates
1
1
Exhibit 2 - Exploratory Boring Log Summaries
1
1
1
1
EnGEN Corporation
1
GEOTECHNICAL BORING LOG
Project Number: 4388GFS Project: Holdaway Residence
Boring Number: B-1 Surface Elevation: 1284
Date: 1-12-18 Logged By: JP
In-Situ OptimumSoiloSampleDryMaximum
Description E USCS Blow Count Moisture Moisture
w Graphic Depth Density Content Density ContentwN
1284
i Colluvium
0
SM
i Medium to fine sand with silt, loose, very moist,
i brown(10YR-413)
1283 1
1
1282 Bedrock 2
Coarse to fine sand with silt, moderately dense,
slightly moist, yellowish brown(10YR-5/8)
1281 3
BOTTOM OF EXCAVATION PIT
NO EVIDENCE OF HISTORICAL
GROUNDWATER
1280 NO GROUNDWATER ENCOUNTERED 4
1
1279 5
1
1278 6
1277 7
Notes:
EnGEN Corporation
1
GEOTECHNICAL BORING LOG
t
Project Number: 4388GFS Project: Holdaway Residence
Boring Number: B-2 Surface Elevation: 1287
Date: 1-12-18 Logged By: JP
g In-Situ OptimumSoilo- Sample Dry MaximumDescriptionEUSCSBlowCountMoisture Moisture
m Graphic toDepth Density Content Density Contentw
1287
Colluvium
0
SM
Medium to fine sand with silt, loose,very moist,
brown (10YR-4/3)
1286 1
1
1285 l Bedrock 2
Coarse to fine sand with silt, moderately dense,
moist,yellowish brown(10YR-5/8)
1284 BOTTOM OF EXCAVATION PIT 3
NO EVIDENCE OF HISTORICAL
GROUNDWATER
NO GROUNDWATER ENCOUNTERED
1283 4
1
1282 5
1
1281 6
1280 7
Notes:
EnGEN Corporation
GEOTECHNICAL BORING LOG
Project Number: 4388GFS Project: Holdaway Residence
Boring Number: B-3 Surface Elevation: 1299
Date: 1-12-18 Logged By: JP
c
In-Situ OptimummSail
Description E Sample
USCS Blow Count Dry Moisture Maximum Moisture
w Graphic m Depth Density Density
w a Content Content
1299
Colluvium
0
SM
Medium to fine sand with silt, loose,very moist,
brown (10YR-4/3)
1298 1
1297 2
Bedrock
Coarse to fine sand with silt, moderately dense,
slightly moist, yellowish brown(10YR-5/8)
1296 3
tBOTTOM OF EXCAVATION PIT
NO EVIDENCE OF HISTORICAL
GROUNDWATER
1295 NO GROUNDWATER ENCOUNTERED 4
1
1294 5
1
1293 6
1
1292 7
Notes:
EnGEN Corporation
LEGEND - KEY TO SYMBOLS
Symbol Description
Graphic Representation Descriptions
Silty sand
Notes:
1. Exploratory excavatons were performed on the dates indicated on the logs.
2. No groundwater was encountered at the time of excavations were made.
3. Locations were taped from existing features. Elevations are from the plans prepared by others
4. Logs are subject to the limitations and recommendations of the report perpared by EnGEN Corporation.
5. Results of tests conducted ------I recovered ma be re orted on the to s.
Paul Holdaway—Holdaway Residence
Project Number:4388GFS
February 2018
Plates
Exhibit 3 - Typical Grading Detail
1
1
1
1
1
1
EnGEN Corporation
KEY AND BENCHING DETAIL
t FILL SLOPE
PROJECT ITO 1 LINE
FROM TOE OF SLOPE
TO COMPETENT MATERIAL
EXISTING
GROUND SURFACE
l==-1= _ REMOVE
UNSUITABLE
wZ-_
MATERIALl----
1 BENCH
2'MIN.KEY DEPTH jgy MlN. MIN 5')
1 I p
10'MIN.
EQUIPMENT WIDTH)
FILL-OVER-CUT SLOPE
1 COMPARED FILL-----------11_—________
EXISTING
GROUND SURFACE
REMOVE
1------- UNSUITABLE
MATERIAL
BENCH SURDRgIN - BAC KDRAIN DETAIL
2'MIN.KEY DEPTH --Z%MIN.t—'- "'0: MIN S)WHEN REQUIRED)
fff=
ospsppuepelosp@ppusosu@p
@upupp@lY@ps so@loslueplO'MIN.—
L
ppplu(
EQUIPMENT WIDTH) I psupp=
CUT SLOPE9'Minmum Diameter ABS OB PVC @OPieorA(
TO BE EXCAVATED PRIOR i pprovedationb teemminimum8'seperation between l/4'
TO FILL PLACEMENT) diameter perforations,per linear foot in bottom.
Subdrain should daytightto suitable drscharge Note:An approved filter fabric
facility per geotechnical engineer's approval.
Burnet.)may be wrapped
around 3/4"crushed ruck
or pea gravel.
CUT-OVER-FILL SLOPE
PROJECT 1 TO 1 LINE
FROM TOE OF SLOPE 77- II CUT SLOPE
70 COMPETENT MATERIAL y--
EXISTING
TO BE EXCAVATED PRIOR
TO FILL PLACEMENT)
GROUND SURFACE II
R __
REMOVE
COMPAED FILL_ III
UNSUITABLE
MATERIAL
2'MIN.KEY DEPTH 2%MIN. --i.:'_:.
10'MIN. BENCH En' EN
EQUIPMENT WIDTH) I (MIN 5) 41625 Enterprise Circle 5outh,"8-2"
951)296-3511 •FaH:(951)296-3711
Note:Back drain may be recommended by the geotechnical consultant based on actual field conditions www.engencorp.com
encountered. Bench dimension recommendations may also be altered on field conditions encountered.
1
GENERAL GRADING RECOMMENDATIONS
CUT LOT
oRIGIN?'ROUND -
I
MINIMUM 5'SET54CN
Ffl OM STR UCTURE
51Min.
3 MINIMU
COMPARED PILL E /!,
OVEREXCAVATE AND RECOMPACT
IN ACCORDANCE WITH RECOMMENDATIONS
GEOTECHNICAL REPORT
NOTE DEEPER EXCAVATION MAY BE
SUITABLESOILOR REQUIRED BYTHEGEOTECHNICAL
GEOLOGIC UNIT ENGINEER IN STEEP TRANSITIONS
CUT-FILL LOT (TRANSITION)
1
MINIMUM S'5 ETBAC K
FROM STfl UC%
5'Min.
101,
y
MINIMU
COMPACTED FILL
OVEREXCAVATE AND RECOM PACT
J
IN ACCORDANCE WITH RECOMMENDATIONS
JS OC. OF THE GEOTECHNICAL REPORT
SUITABLE SOIL OR O_ F-O /
Q5 _P / NOTE : DEEPER EXCAVATION MAYBE
GEOLOGIC UNIT O
p<i/ REQUIRED BYTHE GEOTECHNICAL
ENGINEER IN STEEP TRANSITIONS
lMdE_N
41635 Enterydse Ctde South/6Y
951)396 3511.Fax:(951)2%3711
www.en9ercarP.com
Minimum Horizontal Removal Limits
BACKCUT INCLINED
V HORIZONTAL TO V VERTICAL
OR AS DESIGNED BY ENGEN CORPORATION
TO MEET CALOSHA REQUIREMENTS
MEASURE FROM BOTTOM
OF PROPOSED FOOTING
1i
1
j
FILL pP aUi
gypLU1
1
Py
p2 LU
LUVIUM-
o
y
i
KDROCK OR COMPETENT ALLUVIUM (SOIL)
REMOVALS TO EXTEND TO THE HORIZONTAL DISTANCE OUTSIDE
OF THE BUILDING LINES EQUAL TO DEPTH OF REMOVAL (LENGTH = HEIGHT)
EnGFN
41625 Enterprise Circle South,"13-2"
951)296-3511 • Fax:(951)296-3711
w .engencorpcom
tPaul Holdaway—Holdaway Residence
Project Number:4388GFS
February 2018
Plates
1
1
Plate 1 - Geotechnical Feasibility Study Plan
1
1
1
1
EnGEN Corporation
1
PLATE 1
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LEGEND
CQaI = Colluvium overlying Pauba Formation
Approximate Location of Exploratory Borings
72sp),
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GRAPHIC SCALE
BO 20 t80 Geotechnical Feasibility Study Site Planl02040
IJ Project Name: Holdaway Residence I Date: 1/23/18
Project Number: 4388GFS Client: Paul Holdaway
41625 Enterprise Circle South,B-2 -Temecula,California 92590 • 951.296.3511 • engen@engencorp.com www.engencorp.com Legal Description: Parcel 2 of PM 12318 Plate No. 1