HomeMy WebLinkAboutT2719-22-01 Lake Resort Apts 061416 GEOTECHNICAL INVESTIGATION
LAKE RESORT APARTMENTS
EAST OF GRAND AVENUE
AT VAIL STREET
APNS 371 -150-001 , 0029
371 -090-0019 AND 002
LAKE ELSINORE, CALIFORNIA
_0 16-1 -11N
T I
E I PREPARED FOR
MATEMLS GRANT BECKLUND CIVIL ENGINEERING
WINCHESTER, CALIFORNIA
PROJECT NO. T2719-22-01
JUNE 2016
Project No. T2719-22-01
June 14, 2016
Mr. Grant Becklund
30811 Garbani Road
Winchester, California 91359
Subject: GEOTECHNICAL INVESTIGATION
LAKE RESORT APARTMENTS
APNS 371-150-001, 002, 371-090-001,AND-002
LAKE ELSINORE, CALIFORNIA
Dear Mr. Becklund:
In accordance with your authorization of Proposal IE-1650 dated April 12, 2016, Geocon West, Inc.
(Geocon) herein submits the results of our geotechnical investigation for the proposed Lake Resort
Apartments located east of Grand Avenue at Vail Street in the City of Lake Elsinore, California.
The accompanying report presents our findings, conclusions and recommendations pertaining to the
geotechnical aspects of the proposed development. Based on the results of this study, it is our opinion
the site is considered suitable for the proposed development provided the recommendations of this report
are followed.
Should you have any questions regarding this report, or if we may be of further service, please contact
the undersigned at your convenience.
Very truly yours,
GEOCON WEST,INC.
Harry Derkalousdian Paul D. Theriault
PE 79694 CEG 2374
(Email) Addressee
TABLE OF CONTENTS
1. PURPOSE AND SCOPE..................................................................................................................1
2. SITE AND PROJECT DESCRIPTION............................................................................................1
3. GEOLOGIC SETTING.....................................................................................................................2
4. GEOLOGIC MATERIALS...............................................................................................................3
4.1 General....................................................................................................................................3
4.2 Undocumented Artificial Fill(afu).........................................................................................3
4.3 Lacustrine Deposits(Ql).........................................................................................................3
4.4 Alluvium(Qal)........................................................................................................................3
4.5 Older Alluvium(Qoal)............................................................................................................3
4.6 Pauba Formation(Qps)...........................................................................................................3
5. GROUNDWATER............................................................................................................................4
6. GEOLOGIC HAZARDS...................................................................................................................4
6.1 Seismic Hazard Analysis........................................................................................................4
6.2 Seismic Design Criteria..........................................................................................................6
6.3 Liquefaction Potential.............................................................................................................7
6.4 Expansive Soil........................................................................................................................8
6.5 Landslides...............................................................................................................................8
6.6 Rock Fall Hazards...................................................................................................................8
6.7 Slope Stability.........................................................................................................................8
6.8 Tsunamis and Seiches.............................................................................................................8
7. CONCLUSIONS AND RECOMMENDATIONS..........................................................................10
7.1 General..................................................................................................................................10
7.2 Soil Characteristics...............................................................................................................12
7.3 Minimum Resistivity,pH, and Water-Soluble Sulfate.........................................................13
7.4 Grading.................................................................................................................................14
7.5 Shrinkage..............................................................................................................................16
7.6 Foundation Design-Mat Foundation..................................................................................16
7.7 Miscellaneous Foundations...................................................................................................17
7.8 Friction Pile Foundations-Light Standards&Carports......................................................17
7.9 Foundation Settlement..........................................................................................................18
7.10 Lateral Design.......................................................................................................................19
7.11 Concrete Slabs-on-Grade......................................................................................................19
7.12 Preliminary Pavement Recommendations............................................................................21
7.13 Retaining Wall Design..........................................................................................................22
7.14 Retaining Wall Drainage.......................................................................................................24
7.15 Elevator Pit Design...............................................................................................................25
7.16 Elevator Piston......................................................................................................................25
7.17 Temporary Excavations........................................................................................................26
7.18 Surface Drainage...................................................................................................................27
7.19 Plan Review..........................................................................................................................27
LIMITATIONS AND UNIFORMITY OF CONDITIONS
LIST OF REFERENCES
TABLE OF CONTENTS (Continued)
MAPS AND ILLUSTRATIONS
Figure 1,Vicinity Map
Figure 2, Geotechnical Map
Figure 3,Regional Geologic Map
Figures 4 and 5,DE Evaluation of Earthquake-Induced Settlements
Figures 6 and 7,MCE Evaluation of Earthquake-Induced Settlements
Figures 8 and 9,Retaining Wall Drainage
APPENDIX A
EXPLORATORY EXCAVATIONS
Figures A-I through A-6,Boring Logs
APPENDIX B
LABORATORY TESTING
Figures BI and B2,Direct Shear Test Results
Figures B3 through B5, Consolidation Test Results
Figure B6,Atterberg Limits
Figure B7, Grain Size Analysis
Figure B8,Laboratory Test Results
Figure B9, Corrosivity Test Results
Appendix C
Fault Hazard Report by Terra Geosciences
Appendix D
Standard Grading Specifications
GEOTECHNICAL INVESTIGATION
1. PURPOSE AND SCOPE
This report presents the results of our geotechnical investigation for the proposed Lake Resort
Apartments located east of Grand Avenue at Vail Street, in the City of Lake Elsinore, California as
depicted on the Vicinity Map,Figure 1. The purpose of the investigation was to evaluate subsurface soil
and geologic conditions at the site and,based on the conditions encountered,provide recommendations
pertaining to the geotechnical aspects of developing the property to accommodate the proposed
apartment buildings and associated improvements.
The scope of our investigation included a site reconnaissance,subsurface exploration,percolation testing,
laboratory testing,engineering analyses,and the preparation of this report.A summary of the information
reviewed for this study is presented in the List of References.
Our field investigation was performed on May 12, 2016, and included the excavation of six hollow
stem borings.Appendix A presents a discussion of the field investigation, and logs of the excavations.
The approximate locations of the exploratory excavations are presented on the Geotechnical Map,
Figure 2. We performed laboratory tests on soil samples obtained from the exploratory excavations to
evaluate pertinent physical and chemical properties for engineering analysis. The results of the
laboratory testing are presented in Appendix B.
2. SITE AND PROJECT DESCRIPTION
We referred to the preliminary Site Plan, prepared by Gary Becklund Civil Engineering to aid in our
investigation and as a basis for Figure 2. References to elevations presented in this report were obtained
from the Site Plan. Geocon does not practice in the field of land surveying and is not responsible for the
accuracy of such topographic information.
The site is rectangular in shape and is approximately 13.5 acres. The portion of the site that will be
improved is approximately 6 acres. Topography within the proposed improved portion of the site is
generally flat with drainage generally toward the northwest. The portion of the site which will be
developed has a high elevation of approximately 1,276 feet above mean sea level(MSL)at the southern
corner and a low of approximately 1,260 feet MSL near the north central portion of the site. Sparse trees
were observed as well as abundant weeds and grasses.
The northern end of the overall parcel has a small hill that reaches an elevation of approximately
1,283 MSL before descending to approximately 1,245 MSL. This area is not part of the proposed
development due to its proximity to the Lake Elsinore flood plain, and an active strand of the
Wildomar fault.
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Proposed development consists of the construction of 126 apartments in four three-story buildings, a
clubhouse,associated on-grade parking,and three storm water infiltration areas,with associated paving,
flatwork and utility improvements.A gas station is proposed within the western portion of the site along
Grand Avenue. All structures will be constructed at or near present site grade.
Due to preliminary nature of the design at this time, wall and column loads were not available. It is
anticipated that column loads for the proposed structure will be up to 400 kips,and wall loads will be up
to 4 kips per linear foot.
Once the design phase and foundation loading configuration proceeds to a more finalized plan, the
recommendations within this report should be reviewed and revised, if necessary. Any changes in the
design,location or elevation of any structure,as outlined in this report,should be reviewed by this office.
Geocon should be contacted to determine the necessity for review and possible revision of this report.
3. GEOLOGIC SETTING
The site is located within the Peninsular Ranges Geomorphic Province (Province) at the boundary of
the Perris and Santa Ana Mountain Blocks. In the vicinity of the site,the Perris Block is characterized
by sandstone highlands which display elevated erosional surfaces surrounded by alluviated and fault
bounded valleys. The Santa Ana Mountains Block is characterized by heterogeneous granitic bedrock
with a moderate amount of volcanic and metamorphic rocks, and some terrestrial sedimentary rocks.
The Peninsular Ranges are bound by the Transverse Ranges (San Gabriel and San Bernardino
Mountains) to the north and the Colorado Desert Geomorphic Province to the east. The Peninsular
Ranges Geomorphic Province extends westward into the Pacific Ocean and southward to the tip of
Baja California. Overall, the Province is characterized by Cretaceous-age granitic rock and a lesser
amount of Mesozoic-age metamorphic rock overlain by terrestrial and marine sediments. Faulting
within the Province is typically northwest trending and includes the San Andreas, San Jacinto,
Elsinore, and Newport-Inglewood faults. Locally, the site is in the Elsinore Valley, a pull apart basin
as result a step over within the Elsinore Fault Zone.Conversely,Rome Hill located just to the southeast
(and the moderate relief hill located in the northeastern portion of the site) are the result of
compressional stresses of strike slip faulting within the zone. The Wildomar strand of the Elsinore
fault zone bisects the parcel northeast of the proposed development. The site with respect to mapped
strands of the Elsinore fault is show on the Regional Geologic Map, Figure3.
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4. GEOLOGIC MATERIALS
4.1 General
Site geologic materials encountered consist of undocumented artificial fill, alluvium, lacustrine
deposits, and older alluvium. Although not encountered during our subsurface exploration, Pauba
Formation was observed as the composition of the hill northeast of the proposed site development.
The descriptions of the soil and geologic conditions are shown on the boring logs located in Appendix
A, the Geotechnical Map (Figure 2), and described herein; generally following the nomenclature of
Morton and Webber, 2007 (see List of References).
4.2 Undocumented Artificial Fill (afu)
Undocumented fill was observed in borings B-5 and B-6. This unit consisted of silty sand that was
medium dense,slightly moist to moist,gray to brown,and has varying amounts of debris,including rocks
and asphaltic concrete.
4.3 Lacustrine Deposits (QI)
Lacustrine (lake) deposits were observed in borings B-5 and B-6. This unit consisted of fine-grained
sandy silt that was firm to stiff,moist,grayish brown to olive, and micaceous.
4.4 Alluvium (Qal)
Alluvium was encountered in all the borings. This unit consisted predominately of silty sand that was
loose to medium dense, slightly moist to wet, dark brown to brown with some mottling, with the sand
portion consists of fine to coarse sand, and varying amounts of gravel. There were lesser amounts of
sandy clays and sandy silts that were predominately stiff,moist, and grayish brown to brown.
4.5 Older Alluvium (goal)
Quaternary-age (late Pleistocene) older alluvial deposits were observed in borings B-1, B-3, and B-4.
This unit consisted predominately of silty sand that was dense to very dense, moist, brown to grayish
brown with some orange mottling. Some gravel was observed as well as a minor amount of sandy clay.
4.6 Pauba Formation (Qps)
Although not encountered during our subsurface exploration, Pauba Formation was observed just
northeast of the northeastern limit of proposed development. This unit consists predominately of a
fine- to coarse-grained silty sandstone that is moderately to well indurated, yellowish brown to brown,
and locally massive to moderately bedded. Varying amounts of gravel were also observed.
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5. GROUNDWATER
Groundwater was encountered in boring B-1 at a depth of 36 feet, 11 inches, and it stabilized at
26 feet, 6 inches during drilling. California Department of Water Resources well data indicates
groundwater has been measured at depths of approximately 56 to 58 feet below the ground surface in
nearby wells. During the rainy season, localized perched water conditions may develop above less
permeable units that may require special consideration during grading operations. Groundwater
elevations and seepage are dependent on seasonal precipitation, irrigation, and land use, among other
factors, and vary as a result.
6. GEOLOGIC HAZARDS
6.1 Seismic Hazard Analysis
It is our opinion, based on a review of published geologic maps and reports, that the site is not
located within a State of California Earthquake Special Studies Zone. However, the site is located
within a Riverside County Fault Zone. The Wildomar strand of the Elsinore fault zone bisects the
site as shone on the Regional Geologic Map (Figure 3). A previous fault investigation performed by
Terra Geosciences (2015) identified a fault zone approximately 320 feet wide and provided
recommended building setback zones. The setback zones are shown on Figure 2. Another setback
zone was established to the northeast due to lack of trenching in that area. The second setback zone
is outside of the proposed development and is northeast of the limits shown on Figure 2. A potential
fault is shown on Figure 3 in the central portion of the site, and was identified as a lineament during
a review of aerial photographs. The Terra Geosciences report identified the lineament as a high water
stand of Lake Elsinore. Trenching across the lineament confirmed a lack faulting in that area.
The Terra Geosciences report is provided in Appendix C herein for ease of reference.
Significant active faults within a 100 kilometer radius of the site are listed in Table 6.1.1 and include,
direction and distance from the site, and the potential magnitude. Historic earthquakes of magnitude
6.0 and greater within 100 miles of the site are listed in Table 6.1.2 below and include the fault name,
direction and distance from the site, and the magnitude of the seismic event.
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TABLE 6.1.1
SIGNIFICANT ACTIVE FAULTS WITHIN 100 KM OF THE SITE
Distance from
Fault Direction Site(km) Magnitude
Elsinore E 0 6.8
Casa Loma(San Jacinto) NE 34 6.9
Claremont(San Jacinto) NE 37 6.9
Chino-Central Avenue NNW 40 6.7
Newport Inglewood W 48 7.1
Whittier NW 51 6.8
San Andreas NNE 56 7.5
Cucamonga NW 61 6.9
Coronado Bank SW 69 7.2
San Diego Trough SW 85 7.2
Rose Canyon SW 90 7.2
TABLE 6.1.2
Historic Earthquake Events with Respect to the Site
Earthquake Distance to Direction
Date of Earthquake Magnitude Epicenter to
(Oldest to Youngest) (Miles) Epicenter
Wrightwood December 12, 1812 7.5 56 NNW
Mira Loma December 16, 1858 6.0 27 NNW
San Jacinto December 25, 1899 6.7 6 NE
San Jacinto April 21, 1918 6.8 6 NE
Loma Linda Area July 22, 1923 6.3 21 NNW
Long Beach March 10, 1933 6.4 50 W
Buck Ridge March 25, 1937 6.0 53 ESE
Imperial Valley May 18, 1940 6.9 52 ENE
Desert Hot Springs December 4, 1948 6.0 44 ENE
Arroyo Salada March 19, 1954 6.4 65 ESE
Borrego Mountain April 8, 1968 6.5 71 ESE
San Fernando February 9, 1971 6.6 95 WNW
Joshua Tree April 22, 1992 6.1 52 ENE
Landers June 28, 1992 7.3 53 NE
Big Bear June 28, 1992 6.4 38 NNE
Northridge January 17, 1994 6.7 97 WNW
Hector Mine October 16, 1999 7.1 80 NE
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6.2 Seismic Design Criteria
We used the computer program U.S. Seismic Design Maps, provided by the USGS, to aid in our seismic
design. Table 6.2.1 summarizes site-specific design criteria obtained from the 2013 California Building
Code(CBC;Based on the 2012 International Building Code[IBC]and ASCE 7-10),Chapter 16 Structural
Design, and Section 1613 Earthquake Loads. The short spectral response uses a period of 0.2 second.
The building structure and improvements should be designed using a Site Class D. We evaluated the
Site Class based on the discussion in Section 1613.3.2 of the 2013 CBC and Table 20.3-1 of ASCE 7-10.
The values presented in Table 6.2.1 are for the risk-targeted maximum considered earthquake(MCER).
TABLE 6.2.1
2013 CBC SEISMIC DESIGN PARAMETERS
Parameter Value 2013 CBC Reference
Site Class D Section 1613.3.2
MCER Ground Motion Spectral Response 2.333 g Figure 1613.3.1(1)
Acceleration—Class B(short), Ss
MCER Ground Motion Spectral Response 0.943 g Figure 1613.3.1(2)
Acceleration—Class B(1 sec),Si
Site Coefficient,Fa 1.0 Table 1613.3.3(1)
Site Coefficient,Fv 1.5 Table 1613.3.3(2)
Site Class Modified MCER Spectral Response 2.333 g Section 1613.3.3 (Eqn 16-37)
Acceleration(short), SMs
Site Class Modified MCER Spectral Response 1.415 g Section 1613.3.3 (Eqn 16-38)
Acceleration(1 sec),Sm,
5%Damped Design 1.555 g Section 1613.3.4(Eqn 16-39)
Spectral Response Acceleration(short),SDs
5%Damped Design 0.943 g Section 1613.3.4(Eqn 16-40)
Spectral Response Acceleration(1 sec),SDI
Table 6.2.2 presents additional seismic design parameters for projects located in Seismic Design
Categories of D through F in accordance with ASCE 7-10 for the mapped maximum considered
geometric mean(MCEG).
TABLE 6.2.2
2013 CBC SITE ACCELERATION DESIGN PARAMETERS
Parameter Value ASCE 7-10 Reference
Mapped MCEG Peak Ground Acceleration, 0.932 Figure 22-7
PGA
Site Coefficient,FPGA 1.0 Table 11.8-1
Site Class Modified MCEG Peak Ground 0.932 g Section 11.8.3 (Eqn 11.8-1)
Acceleration,PGAI I
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Conformance to the criteria in Tables 6.2.1 and 6.2.2 for seismic design does not constitute any kind of
guarantee or assurance that significant structural damage or ground failure will not occur if a large
earthquake occurs. The primary goal of seismic design is to protect life, not to avoid all damage, since
such design may be economically prohibitive.
6.3 Liquefaction Potential
Liquefaction is a phenomenon in which loose, saturated,relatively cohesionless soil deposits lose shear
strength during strong ground motions. Primary factors controlling liquefaction include intensity and
duration of ground motion,gradation characteristics of the subsurface soils,in-situ stress conditions,and
the depth to groundwater. Liquefaction is typified by a loss of shear strength in the liquefied layers due
to rapid increases in pore water pressure generated by earthquake accelerations.
The current standard of practice, as outlined in the "Recommended Procedures for Implementation of
DMG Special Publication 117, Guidelines for Analyzing and Mitigating Liquefaction in California"
and "Special Publication 117A, Guidelines for Evaluating and Mitigating Seismic Hazards in
California"requires liquefaction analysis to a depth of 50 feet below the lowest portion of the proposed
structure. Liquefaction typically occurs in areas where the soils below the water table are composed
of poorly consolidated, fine to medium-grained, primarily sandy soil. In addition to the requisite soil
conditions,the ground acceleration and duration of the earthquake must also be of a sufficient level to
induce liquefaction.
A review of the County of Riverside Land Information System indicates that the site is located within
an area designated as having a high potential for liquefaction.
Liquefaction analysis of the soils underlying the site (approximate elevation of 1,262 through
1,212 feet MSL was performed using an updated version of the spreadsheet template LIQ2_30.WQ1
developed by Thomas F. Blake (1996). This program utilizes the 1996 NCEER method of analysis.
This semi-empirical method is based on a correlation between values of Standard Penetration Test
(SPT)resistance and field performance data.
The liquefaction analysis was performed for a Design Earthquake level by using a "model" historic
high groundwater table of 5 feet below the ground surface, a magnitude 6.89 earthquake, and a peak
horizontal acceleration of 0.622g (%PGAM). The enclosed liquefaction analyses, included herein for
boring B1, indicates that the alluvial soils below the proposed foundation level would be prone to
approximately 3 inches of liquefaction settlement during Design Earthquake ground motion,
respectively(see enclosed calculation sheets, Figures 4 and 5). The resulting differential settlement at
the ground surface is anticipated to be approximately 1.5 inch over a distance of 50 feet.
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It is our understanding that the intent of the Building Code is to maintain "Life Safety" during
Maximum Considered Earthquake level events. Therefore, additional analysis was performed to
evaluate the potential for liquefaction during a MCE event. The structural engineer should evaluate
the proposed structure for the anticipated MCE liquefaction induced settlements and verify that
anticipated deformations would not cause the foundation system to lose the ability to support the
gravity loads and/or cause collapse of the structure.
The liquefaction analysis was also performed for Maximum Considered Earthquake levels by using a
"model"historic high groundwater table of 5 feet below the ground surface,a magnitude 7.03 earthquake,
and a peak horizontal acceleration of 0.932g(PGAM).The enclosed liquefaction analysis,included herein
for boring B 1, indicates that the alluvial soils below the proposed foundation would be prone to
approximately 3 inches of liquefaction settlement during Maximum Considered Earthquake ground
motion(see enclosed calculation sheets,Figures 6 and 7).
6.4 Expansive Soil
The geologic units generally consist of silty sands. Laboratory testing results indicate a sample of the
fine-grained soil unit exhibits a"very low"expansion potential with an expansion index of 3 as defined
by ASTM International(ASTM)D4829.
6.5 Landslides
There are no steep slopes on or adjacent to the site. Therefore, landslides are not a design consideration
for the site.
6.6 Rock Fall Hazards
The closest mountains are the Santa Ana Mountains, approximately 1,000 feet to the west. Due to
shallow moderate slope angle,the moderate soil development, and abundant brush on the slopes, rock
falls are not a design consideration for the site.
6.7 Slope Stability
Based on the preliminary site plan and relatively flat site topography, it does not appear that significant
slopes will be constructed. Therefore, slope stability will not be a design consideration for the site.
6.8 Tsunamis and Seiches
A tsunami is a series of long period waves generated in the ocean by a sudden displacement of large
volumes of water. Causes of tsunamis include underwater earthquakes,volcanic eruptions,or offshore
slope failures. The first order driving force for locally generated tsunamis offshore southern California
is expected to be tectonic deformation from large earthquakes (Legg, et al., 2003). The site is located
more than 22 miles from the nearest coastline with a mountain range in between; therefore, risk
associated with tsunamis is not a design consideration.
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A seiche is a run-up of water within a lake or embayment triggered by fault- or landslide-induced
ground displacement. Lake Elsinore is located approximately 1,600 feet north of the site and has a
water surface elevation of approximately 1,238 feet MSL. Healthy lake water surface elevations are
1,244 feet MSL and outflow channel elevations are 1,255 feet MSL. The hill located just northwest of
the proposed development acts as a barrier between the site and the lake,with a peak of approximately
1,283 feet MSL. Further,the proposed development elevations will be approximately 1,268 feet MSL.
Therefore, seiches are not a design consideration for the site.
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7. CONCLUSIONS AND RECOMMENDATIONS
7.1 General
7.1.1 It is our opinion that neither soil nor geologic conditions were encountered during the
investigation that would preclude construction of the proposed project provided the
recommendations presented herein are followed and implemented during design and
construction.
7.1.2 Up to 6'/2 feet of existing artificial fill was encountered during the site investigation.
The existing fill encountered is believed to be the result of past grading, construction, and
demolition activities at the site. Deeper fill may exist in other areas of the site that were not
directly explored. It is our opinion that the existing fill,in its present condition, is not suitable
for direct support of proposed foundations, slabs, or additional fill. The existing fill and site
soils are suitable for re-use as engineered fill provided the recommendations in the Grading
section of this report are followed(see Section 7.4).
7.1.3 The enclosed seismically-induced settlement analysis indicates that alluvial soils underlying
the site could be prone to approximately 3 inches of liquefaction settlement as a result of the
Design Earthquake peak ground acceleration(2/3PGAM).The resulting differential settlement
at the ground surface is anticipated to be approximately 1.5 inch over a distance of 50 feet.
The foundation recommendations presented in Section 7.6 are intended to minimize the
effects of settlement on proposed improvements.
7.1.4 The results of laboratory testing indicate that the upper 7 feet of site soils are subject to
hydro-consolidation upon saturation (see Figures B-3 and B-4). Hydro-consolidation is the
tendency of a soil structure to collapse upon saturation resulting in the overall settlement of
the effected soils and any overlying foundations supported therein. Once the excavation
bottom for the building pad area has been established, it is recommended that the exposed
bottom be proof-rolled in the presence of the Geotechnical Engineer (a representative of
Geocon). Any exposed soft soil and soils unintentionally disturbed should be properly
compacted for foundation and slab support. All excavation bottoms must be observed and
approved in writing by the Geotechnical Engineer, prior to placing bedding materials, fill,
steel, gravel or concrete.
7.1.5 Based on these considerations, it is recommended that the upper 7 feet of existing earth
materials (approximate elevation of 1,262 feet MSL) within the building footprint areas be
excavated and properly compacted for foundation, slab, and additional fill support. Deeper
excavations should be conducted as needed to remove any encountered fill or soft soils
as necessary at the direction of the Geotechnical Engineer. The excavation should extend
laterally a minimum distance of 7 feet beyond the building footprint areas, including
Geocon Project No.T2719-22-01 - to- June 14,2016
building appurtenances,or a distance equal to the depth of fill below the foundation,whichever
is greater. Proposed foundations should be underlain by at least 3 feet of newly compacted
engineered fill. The limits of existing fill and/or soft soil removal will be verified by the
Geocon representative during site grading activities. Recommendations for earthwork are
provided in the Grading section of this report(see Section 7.4).
7.1.6 Subsequent to the recommended grading, it is recommended that the proposed structures be
supported on a reinforced concrete mat foundation system. A mat foundation is more capable
of distributing the structural loads applied to the soil and therefore minimizing potential
settlements. It is recommended that the mat foundation derive support on a blanket of newly
placed engineered fill.
7.1.7 It is anticipated that stable excavations for the recommended grading associated with the
proposed structures can be achieved with sloping measures. However, if excavations in
proximity to an adjacent property line and/or structure are required, special excavation
measures may be necessary in order to maintain lateral support of offsite improvements.
Excavation recommendations are provided in the Temporary Excavations section of this
report(Section 7.17).
7.1.8 Foundations for small outlying structures, such as block walls up to 6 feet high,planter walls
or trash enclosures, which will not be tied to the proposed structure, may be supported on
conventional foundations bearing on a minimum of 12 inches of newly placed engineered
fill which extends laterally at least 12 inches beyond the foundation area. Where excavation
and proper compaction cannot be performed or is undesirable, foundations may derive
support directly in the dense undisturbed old alluvium generally found at or below a depth
of 18 inches, and should be deepened as necessary to maintain a minimum 12-inch
embedment into the recommended bearing materials. If the soils exposed in the excavation
bottom are soft or loose, compaction of the soils will be required prior to placing steel or
concrete. Compaction of the foundation excavation bottom is typically accomplished with a
compaction wheel or mechanical whacker and must be observed and approved by a Geocon
representative.
7.1.9 Where new paving is to be placed, it is recommended that all existing fill and soft alluvial
soils be excavated and properly compacted for paving support. The client should be aware
that excavation and compaction of all existing fill and soft alluvial soils in the area of new
paving is not required; however, paving constructed over existing uncertified fill or
unsuitable alluvial soil may experience increased settlement and/or cracking, and may
therefore have a shorter design life and increased maintenance costs. As a minimum, the
upper 12 inches of subgrade soil should be scarified and properly compacted for paving
support.Paving recommendations are provided in Preliminary Pavement Recommendations
section of this report(see Section 7.12).
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7.1.10 All excavations must be observed and approved in writing by the Geotechnical representative.
Prior to placing any fill,the excavation bottom must be proof-rolled with heavy equipment in
the presence of the Geotechnical Engineer.
7.1.11 Once the design and foundation loading configuration for the proposed structures proceeds
to a more finalized plan, the recommendations within this report should be reviewed and
revised, if necessary. Based on the final foundation loading configurations,the potential for
settlement should be re-evaluated by this office.
7.1.12 Any changes in the design,location or elevation,as outlined in this report, should be reviewed
by this office. Geocon should be contacted to determine the necessity for review and possible
revision of this report.
7.1.13 The most recent ASTM standards apply to this project and must be utilized, even if older
ASTM standards are indicated in this report.
7.2 Soil Characteristics
7.2.1 The in-situ soils can be excavated with moderate effort using conventional excavation
equipment. Some caving should be anticipated in unshored excavations, especially where
granular soils are present.
7.2.2 It is the responsibility of the contractor to ensure that all excavations and trenches are properly
shored and maintained in accordance with applicable OSHA rules and regulations to maintain
safety and maintain the stability of existing adjacent improvements.
7.2.3 All onsite excavations must be conducted in such a manner that potential surcharges from
existing structures, construction equipment, and vehicle loads are resisted. The surcharge
area may be defined by a 1:1 projection down and away from the bottom of an existing
foundation or vehicle load. Penetrations below this 1:1 projection will require special
excavation measures such as sloping or shoring. Excavation recommendations are provided
in the Temporary Excavations section of this report(see Section 7.17).
7.2.4 The upper 5 feet of site soils encountered in the field investigation are considered to be
"Non-Expansive" (very low Expansion Index [EI] of 3 based on ASTM D4829, See Figure
B8) as defined by 2013 California Building Code (CBC) Section 1803.5.3. Table 7.2.4
presents soil classifications based on the EI.Recommendations presented herein assume that
the building foundations and slabs will derive support in these materials
Geocon Project No.T2719-22-01 - 12- June 14,2016
TABLE 7.2.4
SOIL CLASSIFICATION BASED ON EXPANSION INDEX
Expansion Index(EI) Expansion Classification 2013 CBC Expansion Classification
0—20 Very Low Non-Expansive
21 —50 Low
51 —90 Medium
91— 130 High Expansive
Greater Than 130 Very High
7.3 Minimum Resistivity, PH, and Water-Soluble Sulfate
7.3.1 Potential of Hydrogen (pH) and resistivity testing as well as chloride content testing were
performed on representative samples of soil to generally evaluate the corrosion potential to
surface utilities. The tests were performed in accordance with California Test Method
Nos. 643 and 422 and indicate that the soils are considered "moderately corrosive" with
respect to corrosion of buried ferrous metals on site. The results are presented in Appendix B
(Figure B-9) and should be considered for design of underground structures.
7.3.2 Laboratory tests were performed on representative samples of the site materials to measure
the percentage of water-soluble sulfate content. Results from the laboratory water-soluble
sulfate tests are presented in Appendix B(Figure B-9) and indicate that the on-site materials
possess"negligible"sulfate exposure to concrete structures as defined by 2013 CBC Section
1904 and ACI 318-11 Sections 4.2 and 4.3.
TABLE 7.3.2
REQUIREMENTS FOR CONCRETE
EXPOSED TO SULFATE-CONTAINING SOLUTIONS
Water-Soluble Maximum Minimum
Sulfate Exposure Sulfate Cement Water to
Exposure Class Percent Type Cement Ratio Compressive
by Weight by Weight Strength(psi)
Negligible SO 0.00-0.10 -- -- 2,500
Moderate S 1 0.10-0.20 II 0.50 4,000
Severe S2 0.20-2.00 V 0.45 4,500
Very Severe S3 >2.00 V+Pozzolan 0.45 4,500
or Slag
7.3.3 Geocon West, Inc. does not practice in the field of corrosion engineering and mitigation.
If corrosion sensitive improvements are planned, it is recommended that a corrosion engineer
be retained to evaluate corrosion test results and incorporate the necessary precautions to avoid
premature corrosion.
Geocon Project No.T2719-22-01 - 13- June 14,2016
7.4 Grading
7.4.1 Grading is anticipated to include preparation of building pad, excavation of site soils for
proposed foundations,utility trenches, and placement of backfill for utility trenches.
7.4.2 Earthwork should be observed, and compacted fill tested by representatives of Geocon.
The existing fill encountered during exploration is suitable for re-use as an engineered fill,
provided any encountered oversize material (greater than 6 inches) and any encountered
deleterious debris is removed.
7.4.3 A preconstruction conference should be held at the site prior to the beginning of
grading operations with the owner, contractor, civil engineer, geotechnical engineer, and,
if applicable, building official in attendance. Special soil handling requirements can be
discussed at that time.
7.4.4 Grading should commence with the removal of all existing vegetation and existing
improvements from the area to be graded. Deleterious debris such as wood and root
structures should be exported from the site and should not be mixed with the fill soils.
Asphalt and concrete should not be mixed with the fill soils unless approved by the
Geotechnical Engineer.All existing underground improvements planned for removal should
be completely excavated and the resulting depressions properly backfilled in accordance
with the procedures described herein. Once a clean excavation bottom has been established
it must be observed and approved in writing by the Geotechnical Engineer.
7.4.5 As a minimum, it is recommended that the upper 7 feet of existing earth materials
(approximate elevation of 1,262 feet MSL) within the proposed building footprint areas be
excavated and properly compacted for foundation and slab support. Deeper excavations
should be conducted as necessary to remove deeper artificial fill or soft alluvial soil at the
direction of the Geotechnical Engineer. The excavation should extend laterally a minimum
distance of 7 feet beyond the building footprint area, including building appurtenances, or a
distance equal to the depth of fill below the foundation, whichever is greater. Proposed
foundations should be underlain by at least three feet of newly compacted engineered fill.
The limits of existing fill and/or soft alluvial soils removal will be verified by the Geocon
representative during site grading activities.
7.4.6 All excavations must be observed and approved in writing by the Geotechnical Engineer.Prior
to placing any fill, the excavation bottom must be proof-rolled with heavy equipment in the
presence of the Geotechnical Engineer.
7.4.7 It is anticipated that stable excavations can be achieved with sloping measures. Excavation
recommendations are provided in the Temporary Excavations section of this report
(Section 7.17).
Geocon Project No.T2719-22-01 - 14- June 14,2016
7.4.8 All fill and backfill soils should be placed in horizontal loose layers approximately 6 to
8 inches thick, moisture conditioned to near optimum moisture content, and properly
compacted.All man-made fill shall be compacted to a minimum 90 percent of the maximum
dry density per ASTM D 1557 (latest edition).
7.4.9 Where new paving is to be placed, it is recommended that all existing fill and soft
alluvial soils be excavated and properly compacted for paving support. The client should be
aware that excavation and compaction of all existing fill and soft soils in the area of new
paving is not required; however, paving constructed over existing uncertified fill or
unsuitable alluvial soil may experience increased settlement and/or cracking, and may
therefore have a shorter design life and increased maintenance costs. As a minimum, the
upper 12 inches of soil should be scarified, moisture conditioned to near optimum moisture
content,and compacted to at least 95 percent relative compaction for paving support. Paving
recommendations are provided in Preliminary Pavement Recommendations section of this
report(see Section 7.12).
7.4.10 All imported fill shall be observed, tested, and approved by Geocon prior to bringing soil to
the site.Rocks larger than 6 inches in diameter shall not be used in the fill.If necessary,import
soils used as structural fill should have an expansion index less than 20 and corrosivity
properties that are equally or less detrimental to that of the existing onsite soils (see Figure
B-9). If import soils will be utilized in the building pad, the soils must be placed uniformly
and at equal thickness at the direction of the Geotechnical Engineer. Soils can be borrowed
from non-building pad areas and later replaced with imported soils.
7.4.11 Utility trenches should be properly backfilled in accordance with the requirements of the Green
Book (latest edition). The pipe should be bedded with clean sands (Sand Equivalent greater
than 30)to a depth of at least 1 foot over the pipe, and the bedding material must be inspected
and approved in writing by the Geotechnical Engineer. The use of gravel is not acceptable
unless used in conjunction with filter fabric to prevent the gravel from having direct contact
with soil. The remainder of the trench backfill may be derived from onsite soil or approved
import soil, compacted as necessary, until the required compaction is obtained. The use of
2-sack slurry is also acceptable.Prior to placing any bedding materials or pipes,the excavation
bottom must be observed and approved in writing by the Geotechnical Engineer.
7.4.12 All trench and foundation excavation bottoms must be observed and approved in writing by
the Geotechnical Engineer prior to placing bedding materials, fill, steel, gravel, or concrete.
7.4.13 If import soils will be utilized in the building pad, the soils must be placed uniformly and at
equal thickness at the direction of the Geotechnical Engineer (a representative of Geocon
West, Inc.). Soils can be borrowed from non-building pad areas and later replaced with
imported soils.
Geocon Project No.T2719-22-01 - 15- June 14,2016
7.5 Shrinkage
7.5.1 Shrinkage results when a volume of material removed at one density is compacted to a higher
density. A shrinkage factor of 15 to 20 percent should be anticipated when excavating
and compacting the upper 7 feet of existing earth materials on the site to an average relative
compaction of 90 percent.
7.6 Foundation Design — Mat Foundation
7.6.1 Subsequent to the recommended grading, a mat foundation system may be utilized for
support of the proposed structure provided foundations derive support on a blanket of newly
placed engineered fill. Proposed foundations should be underlain by at least 3 feet of newly
compacted engineered fill.
7.6.2 It is anticipated that the mat foundation will impart an average pressure of less than
2,000 pounds per square foot (psf), with locally higher pressures up to 5,000 psf.
The recommended maximum allowable bearing value is 5,000 psf. The allowable bearing
pressure may be increased by up to one-third for transient loads due to wind or seismic forces.
7.6.3 A vertical modulus of subgrade reaction of 280 pounds per cubic inch(pci)may be used in the
design of mat foundations deriving support in newly placed engineered fill.This value is a unit
value for use with a one-foot square footing. The modulus should be reduced in accordance
with the following equation when used with larger foundations:
B+11l2
KR = K I 2BJ
where: Kx=reduced subgrade modulus
K=unit subgrade modulus
B = foundation width(in feet)
7.6.4 The thickness of and reinforcement for the mat foundation should be designed by the project
structural engineer.
7.6.5 No special subgrade presaturation is required prior to placement of concrete. However,
the slab and foundation subgrade should be sprinkled as necessary; to maintain a moist
condition as would be expected in any concrete placement.
7.6.6 For seismic design purposes, a coefficient of friction of 0.40 may be utilized between
the concrete mat and newly placed engineered fill, and 0.15 for slabs underlain by a
moisture barrier.
Geocon Project No.T2719-22-01 - 16- June 14,2016
7.6.7 Foundation excavations should be observed by the Geotechnical Engineer, prior to the
placement of reinforcing steel and concrete to verify that the exposed soil conditions are
consistent with those anticipated. If unanticipated soil conditions are encountered, foundation
modifications may be required.
7.6.8 This office should be provided a copy of the final construction plans so that the excavation
recommendations presented herein could be properly reviewed and revised if necessary.
7.7 Miscellaneous Foundations
7.7.1 Foundations for small outlying structures, such as block walls up to 6 feet in height,planter
walls or trash enclosures which will not be tied to the proposed structure may be supported
on conventional foundations bearing on a minimum of 12 inches of newly placed engineered
fill which extends laterally at least 12 inches beyond the foundation area. Where excavation
and compaction cannot be performed or is undesirable, such as adjacent to property lines,
foundations may derive support in the undisturbed alluvial soils found at or below a depth
of 18 inches, and should be deepened as necessary to maintain a minimum 12-inch
embedment into the recommended bearing materials.
7.7.2 If the soils exposed in the excavation bottom are soft, compaction of the soft soils will
be required prior to placing steel or concrete.Compaction of the foundation excavation bottom
is typically accomplished with a compaction wheel or mechanical whacker and must be
observed and approved by a Geocon representative. Miscellaneous foundations may be
designed for a bearing value of 1,500 psf, and should be a minimum of 12 inches in width,
18 inches in depth below the lowest adjacent grade and 12 inches into the recommended
bearing material. The allowable bearing pressure may be increased by up to one-third for
transient loads due to wind or seismic forces.
7.7.3 Foundation excavations should be observed and approved in writing by the Geotechnical
Engineer,prior to the placement of reinforcing steel and concrete to verify that the excavations
and exposed soil conditions are consistent with those anticipated.
7.8 Friction Pile Foundations — Light Standards & Carports
7.8.1 Typical light standards and monument signs are between 15 and 120 feet in height and are
supported on pile foundations. Cast-in-place friction piles may be utilized for support of
these improvements provided the pile foundations derive support in engineered fill and/or
the undisturbed alluvium. Where piles penetrate through unsuitable fill materials at the
surface,these materials should not be considered in the contribution of the pile capacity.
Geocon Project No.T2719-22-01 - 17- June 14,2016
7.8.2 Piles should be a minimum of 24 inches in diameter, and should be embedded a minimum
of 8 feet into the undisturbed alluvium and/or newly compacted fill. The piles do not require
the complete removal of all loose earth materials from the bottom of the excavation, since
end-bearing capacity is not being considered; however, a cleanout of the excavation bottom
will be required. Piles may be assumed fixed at an embedment depth of five feet below the
ground surface.
7.8.3 The coefficient of friction may be taken as 0.40 based on uniform contact between the
concrete and retained earth. The downward capacity may be determined using a frictional
resistance of 120 psf where piles are in contact with engineered fill or competent alluvial
soils. A one-third increase in the capacity may be used for wind or seismic loads.
7.8.4 All drilled pile excavations should be continuously observed by personnel of this firm to
verify adequate penetration into the recommended bearing materials. The capacity presented
is based on the strength of the soils. The compressive and tensile strength of the pile sections
should be checked to verify the structural capacity of the piles.
7.8.5 Casing will likely be required, since excessive caving is anticipated in the granular soils.
If casing is used, extreme care should be employed so that the pile is not pulled apart as the
casing is withdrawn. At no time should the distance between the surface of the concrete and
the bottom of the casing be less than five feet. Continuous observation of the drilling and
pouring of the piles by the Geotechnical Engineer is required.
7.8.6 Closely spaced piles should be drilled and filled alternately,with the concrete permitted to set
at least eight hours before drilling an adjacent hole. Pile excavations should be filled with
concrete as soon after drilling and inspection as possible; the holes should not be left open
overnight unless approved by the Geotechnical Engineer.
7.9 Foundation Settlement
7.9.1 The enclosed liquefaction analysis indicates that the alluvial soils could be prone to
3 inches of liquefaction settlement as a result of the Design Earthquake ground motion.
The resulting differential settlement at the ground surface is anticipated to be
approximately 1.5 inches over a distance of 50 feet. These settlements are in addition to
the static settlements indicated below and must be considered in the structural design.
Geocon Project No.T2719-22-01 - 18- June 14,2016
7.9.2 The maximum expected static settlement for the structures supported on a mat foundation
system deriving support in newly compacted engineered fill and utilizing a maximum
allowable bearing pressure of 5,000 psf is estimated to be less than 0.75 inch and occur
below the heaviest loaded structural element. Settlement of the foundation system is
expected to occur on initial application of loading. Differential settlement is not expected to
exceed 0.5 inch over a distance of 20 feet.
7.9.3 Based on seismic considerations,the proposed structure supported on a mat foundation system
should be designed for a combined static and seismically induced differential settlement of
less than 1.25 inch over a distance of 20 feet.
7.9.4 Once the design and foundation loading configurations for the proposed structures proceeds
to a more finalized plan, the estimated settlements presented in this report should be
reviewed and revised,if necessary. If the final foundation loading configurations are greater
than the assumed loading conditions (column loads of up to 400 kips, wall loads of up to
4 kips per linear foot), the potential for settlement should be reevaluated by this office.
7.10 Lateral Design
7.10.1 Resistance to lateral loading may be provided by friction acting at the base of foundations,
slabs and by passive earth pressure. An allowable coefficient of friction of 0.40 may be
used with the dead load forces in the undisturbed alluvial soils and newly compacted
engineered fill.
7.10.2 Passive earth pressure for the sides of foundations poured against undisturbed alluvium may
be computed as an equivalent fluid having a density of 280 pounds per cubic foot(pcf)with
a maximum earth pressure of 2,800 psf. When combining passive and friction for lateral
resistance,the passive component should be reduced by one-third.
7.11 Concrete Slabs-on-Grade
7.11.1 Concrete slabs-on-grade subject to vehicle loading should be designed in accordance with
the recommendations in the Pavement Recommendations section of this report(Section 7.12).
7.11.2 Subsequent to the recommended grading, concrete slabs-on-grade for structures,not subject
to vehicle loading, should be a minimum of 4 inches thick and minimum slab reinforcement
should consist of No. 3 steel reinforcing bars placed 18 inches on center in both horizontal
directions. Steel reinforcing should be positioned vertically near the slab midpoint.
Geocon Project No.T2719-22-01 - 19- June 14,2016
7.11.3 Slabs-on-grade at the ground surface that may receive moisture-sensitive floor coverings or
may be used to store moisture-sensitive materials should be underlain by a vapor retarder
placed directly beneath the slab. The vapor retarder and acceptable permeance should be
specified by the project architect or developer based on the type of floor covering that
will be installed. The vapor retarder design should be consistent with the guidelines
presented in Section 9.3 of the American Concrete Institute's (ACI) Guide for Concrete
Slabs that Receive Moisture-Sensitive Flooring Materials (ACI 302.2R-06) and should be
installed in general conformance with ASTM E 1643 (latest edition) and the manufacturer's
recommendations. A minimum thickness of 15 mils extruded polyolefin plastic is
recommended; vapor retarders which contain recycled content or woven materials are not
recommended. The vapor retarder should have a permeance of less than 0.01 perms
demonstrated by testing before and after mandatory conditioning is recommended.
The vapor retarder should be installed in direct contact with the concrete slab with proper
perimeter seal. If the California Green Building Code requirements apply to this project,the
vapor retarder should be underlain by 4 inches of clean aggregate. It is important that the
vapor retarder be puncture resistant since it will be in direct contact with angular gravel.
As an alternative to the clean aggregate suggested in the Green Building Code, it is our
opinion that the concrete slab-on-grade may be underlain by a vapor retarder over 4 inches
of clean sand (sand equivalent greater than 30), since the sand will serve a capillary break
and will minimize the potential for punctures and damage to the vapor barrier.
7.11.4 For seismic design purposes, a coefficient of friction of 0.40 may be utilized between
concrete slabs and subgrade soils without a moisture barrier, and 0.15 for slabs underlain by a
moisture barrier.
7.11.5 Exterior slabs for walkways or flatwork,not subject to traffic loads, should be at least 4 inches
thick and reinforced with No. 3 steel reinforcing bars placed 18 inches on center in both
horizontal directions, positioned near the slab midpoint. Prior to construction of slabs, the
upper 12 inches of subgrade should be moistened to optimum moisture content and properly
compacted to at least 95 percent relative compaction,as determined by ASTM Test Method D
1557(latest edition). Crack control joints should be spaced at intervals not greater than 10 feet
and should be constructed using saw-cuts or other methods as soon as practical following
concrete placement. Crack control joints should extend a minimum depth of one-fourth the
slab thickness. The project structural engineer should design construction joints as necessary.
Geocon Project No.T2719-22-01 -20- June 14,2016
7.11.6 The recommendations of this report are intended to reduce the potential for cracking of slabs
due to settlement. However, even with the incorporation of the recommendations presented
herein, foundations, stucco walls, and slabs-on-grade may exhibit some cracking due to
minor soil movement and/or concrete shrinkage. The occurrence of concrete shrinkage
cracks is independent of the supporting soil characteristics.Their occurrence may be reduced
and/or controlled by limiting the slump of the concrete, proper concrete placement and
curing,and by the placement of crack control joints at periodic intervals,in particular,where
re-entrant slab corners occur.
7.12 Preliminary Pavement Recommendations
7.12.1 Where new paving is to be placed, it is recommended that all existing fill and soft or
unsuitable alluvial materials be excavated and properly compacted for paving support.
The client should be aware that excavation and compaction of all existing artificial fill
and soft alluvium in the area of new paving is not required; however, paving constructed
over existing unsuitable material may experience increased settlement and/or cracking, and
may therefore have a shorter design life and increased maintenance costs. As a minimum,
the upper twelve inches of paving subgrade should be scarified, moisture conditioned
to optimum moisture content, and properly compacted to at least 95 percent relative
compaction, as determined by ASTM Test Method D 1557 (latest edition).
7.12.2 The following pavement sections are based on an assumed R-Value of 35. Once site grading
activities are complete an R-Value should be obtained by laboratory testing to confirm the
properties of the soils serving as paving subgrade,prior to placing pavement.
7.12.3 The Traffic Indices listed below are estimates.Geocon does not practice in the field of traffic
engineering. The actual Traffic Index for each area should be determined by the project civil
engineer. If pavement sections for Traffic Indices other than those listed below are required,
Geocon should be contacted to provide additional recommendations. Pavement thicknesses
were determined following procedures outlined in the California Highway Design Manual
(Caltrans). It is anticipated that the majority of traffic will consist of automobile and large
truck traffic.
TABLE 7.12.3
PRELIMINARY PAVEMENT DESIGN SECTIONS
Location Estimated Traffic Asphalt Concrete Class 2 Aggregate
Index(TI) (inches) Base(inches)
Automobile Parking
4.0 3.0 4.0
And Driveways
Trash Truck& 7.0 4.0 9.0
Fire Lanes
Geocon Project No.T2719-22-01 -21 - June 14,2016
7.12.4 Asphalt concrete should conform to Section 203-6 of the"Standard Specifications for Public
Works Construction" (Green Book). Class 2 aggregate base materials should conform to
Section 26-1.02A of the "Standard Specifications of the State of California, Department of
Transportation" (Caltrans). The use of Crushed Miscellaneous Base in lieu of Class 2
aggregate base is acceptable. Crushed Miscellaneous Base should conform to Section
200-2.4 of the "Standard Specifications for Public Works Construction"(Green Book).
7.12.5 Unless specifically designed and evaluated by the project structural engineer, where exterior
concrete paving will be utilized for support of vehicles, it is recommended that the
concrete be a minimum of 5 inches of concrete reinforced with No. 3 steel reinforcing
bars placed 18 inches on center in both horizontal directions. Concrete paving supporting
vehicular traffic should be underlain by a minimum of 4 inches of aggregate base and a
properly compacted subgrade. The subgrade and base material should be compacted to
95 percent relative compactions determined by ASTM Test Method D 1557 (latest edition).
7.12.6 The performance of pavements is highly dependent upon providing positive surface drainage
away from the edge of pavements. Ponding of water on or adjacent to the pavement will
likely result in saturation of the subgrade materials and subsequent cracking, subsidence and
pavement distress. If planters are planned adjacent to paving, it is recommended that the
perimeter curb be extended at least 12 inches below the bottom of the aggregate base to
minimize the introduction of water beneath the paving.
7.13 Retaining Wall Design
7.13.1 The recommendations presented below are generally applicable to the design of rigid concrete
or masonry retaining walls having a maximum height of 6 feet. In the event that walls
significantly higher than 6 feet are planned, Geocon should be contacted for additional
recommendations.
7.13.2 Retaining wall foundations may be designed in accordance with the recommendations
provided in the Conventional Foundation Design sections of this report(see Section 7.7).
7.13.3 Retaining walls with a level backfill surface that are not restrained at the top should be
designed utilizing a triangular distribution of pressure (active pressure). Restrained walls are
those that are not allowed to rotate more than 0.001H(where H equals the height of the retaining
portion of the wall in feet) at the top of the wall. Where walls are restrained from movement at
the top, walls may be designed utilizing a triangular distribution of pressure (at-rest pressure).
The table below presents recommended pressures to be used in retaining wall design,assuming
that proper drainage will be maintained.
Geocon Project No.T2719-22-01 -22- June 14,2016
TABLE 7.13.3
RETAINING WALL WITH LEVEL BACKFILL SURFACE
ACTIVE PRESSURE AT-REST PRESSURE
HEIGHT OF RETAINING EQUIVALENT FLUID EQUIVALENT FLUID
WALL PRESSURE PRESSURE
(Feet) (Pounds Per Cubic Foot) (Pounds Per Cubic Foot)
Up to 6 30 50
7.13.4 The wall pressures provided above assume that the retaining wall will be properly drained
preventing the buildup of hydrostatic pressure. If retaining wall drainage is not implemented,
the equivalent fluid pressure to be used in design of undrained walls is 90 pcf. The value
includes hydrostatic pressures plus buoyant lateral earth pressures.
7.13.5 Additional active pressure should be added for a surcharge condition due to sloping ground,
vehicular traffic or adjacent structures and should be designed for each condition as the project
progresses.
7.13.6 It is recommended that line-load surcharges from adjacent wall footings, use horizontal
pressures generated from NAV-FAC DM 7.2. The governing equations are:
For /H<_0.4 r
0.201 -J
ae(:)= H 2 Q,.
z H
and
ll
II
For /H>0.4
1.26( x
H) (H) Q
v„(x,:)= l2 L
CH)Z+CH)2 H
where x is the distance from the face of the excavation to the vertical line-load,H is the distance
from the bottom of the footing to the bottom of excavation, z is the depth at which the
horizontal pressure is desired, QL is the vertical line-load and 6H is the horizontal pressure at
depth z.
Geocon Project No.T2719-22-01 -23 - Junc 14,2016
7.13.7 It is recommended that vertical point-loads, from construction equipment outriggers or
adjacent building columns use horizontal pressures generated from NAV-FAC DM 7.2.
The governing equations are:
For /H _<0.4 ( 12
0.28x1 HJ Q�
6 2 3 xHZ
0.16+rH1
and ll JJ
For /H >0.4 2 ( l2
1.77x(H)
xl HJ Q��
a(z)_ l 3 x Z
112 2 j-f
�HJ +�H�
then
al(Z)=6H(Z)COS2(1.10)
where x is the distance from the face of the excavation to the vertical point-load,H is distance
from the outrigger/bottom of column footing to the bottom of excavation, z is the depth at
which the horizontal pressure is desired,Qp is the vertical point-load,a is the vertical pressure
at depth z, 8 is the angle between a line perpendicular to the bulkhead and a line from the
point-load to half the pile spacing at the bulkhead,and Gx is the horizontal pressure at depth z.
7.14 Retaining Wall Drainage
7.14.1 Retaining walls should be provided with a drainage system extended at least two-thirds the
height of the wall. At the base of the drain system, a subdrain covered with a minimum of
12 inches of gravel should be installed,and a compacted fill blanket or other seal placed at the
surface(see Figure 8). The clean bottom and subdrain pipe,behind a retaining wall, should be
observed by the Geotechnical Engineer prior to placement of gravel or compacting backfill.
7.14.2 As an alternative, a plastic drainage composite such as Miradrain or equivalent may be
installed in continuous, 4-foot-wide columns along the entire back face of the wall, at 8 feet
on center. The top of these drainage composite columns should terminate approximately
18 inches below the ground surface, where either hardscape or a minimum of 18 inches of
relatively cohesive material should be placed as a cap (see Figure 9). These vertical columns
of drainage material would then be connected at the bottom of the wall to a collection panel or
a one-cubic-foot rock pocket drained by a 4-inch subdrain pipe.
Geocon Project No.T2719-22-01 -24- Junc 14,2016
7.14.3 Subdrainage pipes at the base of the retaining wall drainage system should outlet to an
acceptable location via controlled drainage structures. Drainage should not be allowed to
flow uncontrolled over descending slopes.
7.14.4 Moisture affecting below grade walls is one of the most common post-construction
complaints. Poorly applied or omitted waterproofing can lead to efflorescence or standing
water. Particular care should be taken in the design and installation of waterproofing to
avoid moisture problems, or actual water seepage into the structure through any normal
shrinkage cracks which may develop in the concrete walls, floor slab, foundations and/or
construction joints. The design and inspection of the waterproofing is not the responsibility
of the geotechnical engineer. A waterproofing consultant should be retained in order to
recommend a product or method, which would provide protection to subterranean walls,
floor slabs and foundations.
7.15 Elevator Pit Design
7.15.1 The elevator pit slab and retaining wall should be designed by the project structural
engineer. Elevator pit walls may be designed in accordance with the recommendations
in the Foundation Design and Retaining Wall Design sections of this report (see Sections
7.9 and 7.13).
7.15.2 Additional active pressure should be added for a surcharge condition due to sloping ground,
vehicular traffic or adjacent foundations and should be designed for each condition as the
project progresses.
7.15.3 If retaining wall drainage is to be provided, the drainage system should be designed in
accordance with the Retaining Wall Drainage section of this report(see Section 7.14).
7.15.4 It is suggested that the exterior walls and slab be waterproofed to prevent excessive moisture
inside of the elevator pit.Waterproofing design and installation is not the responsibility of the
geotechnical engineer.
7.16 Elevator Piston
7.16.1 If a plunger-type elevator piston is installed for this project, a deep drilled excavation will be
required. It is important to verify that the drilled excavation is not situated immediately
adjacent to a foundation or shoring pile, or the drilled excavation could compromise the
existing foundation or pile support, especially if the drilling is performed subsequent to the
foundation or pile construction.
Geocon Project No.T2719-22-01 -25- June 14,2016
7.16.2 Some caving is expected and the contractor should be prepared to use casing and should have
it readily available at the commencement of drilling activities. Continuous observation of the
drilling and installation of the elevator piston by the Geotechnical Engineer(a representative
of Geocon West,Inc.) is required.
7.16.3 The annular space between the piston casing and drilled excavation wall should be filled with
a minimum of 1'/2-sack slurry pumped from the bottom up. As an alternative,pea gravel may
be utilized. The use of soil to backfill the annular space is not acceptable.
7.17 Temporary Excavations
7.17.1 Excavations on the order of 7 feet in height will be required during grading operations.
The excavations are expected to expose artificial fill and alluvial soils, which are suitable for
vertical excavations up to 5 feet in height where loose soils or caving sands are not present,and
where not surcharged by adjacent traffic or structures.
7.17.2 Vertical excavations greater than 5 feet or where surcharged by existing structures
will require sloping or shoring measures in order to provide a stable excavation. Where
sufficient space is available,temporary unsurcharged embankments could be sloped back at
a uniform 1:1 slope gradient or flatter. A uniform slope does not have a vertical portion.
7.17.3 It is anticipated that stable excavations for the recommended grading associated with the
proposed structures can be achieved with sloping measures. However, if excavations in close
proximity to an adjacent property line and/or structure are required, special excavation
measures such as slot-cutting or shoring may be necessary in order to maintain lateral support
of offsite improvements. Recommendations for slot-cutting or shoring measures can be
provided under separate cover once the project has proceeded to a more finalized design, if
necessary.
7.17.4 Where sloped embankments are utilized,the top of the slope should be barricaded to prevent
vehicles and storage loads at the top of the slope within a horizontal distance equal to the
height of the slope. If the temporary construction embankments are to be maintained during
the rainy season,berms are suggested along the tops of the slopes where necessary to prevent
runoff water from entering the excavation and eroding the slope faces. Geocon personnel
should inspect the soils exposed in the cut slopes during excavation so that modifications of
the slopes can be made if variations in the soil conditions occur. All excavations should be
stabilized within 30 days of initial excavation.
Geocon Project No.T2719-22-01 -26- June 14,2016
7.18 Surface Drainage
7.18.1 Proper surface drainage is critical to the future performance of the project. Uncontrolled
infiltration of irrigation excess and storm runoff into the soils can adversely affect the
performance of the planned improvements. Saturation of a soil can cause it to lose internal
shear strength and increase its compressibility,resulting in a change in the original designed
engineering properties. Proper drainage should be maintained at all times.
7.18.2 All site drainage should be collected and controlled in non-erosive drainage devices.
Drainage should not be allowed to pond anywhere on the site,and especially not against any
foundation or retaining wall. The site should be graded and maintained such that surface
drainage is directed away from structures in accordance with 2013 CBC 1804.3 or other
applicable standards. In addition, drainage should not be allowed to flow uncontrolled over
any descending slope. Discharge from downspouts, roof drains and scuppers are not
recommended onto unprotected soils within five feet of the building perimeter. Planters
which are located adjacent to foundations should be sealed to prevent moisture intrusion
into the soils providing foundation support.Landscape irrigation is not recommended within
5 feet of the building perimeter footings except when enclosed in protected planters.
7.18.3 Positive site drainage should be provided away from structures, pavement, and the tops of
slopes to swales or other controlled drainage structures. The building pad and pavement areas
should be fine graded such that water is not allowed to pond.
7.18.4 Landscaping planters immediately adjacent to paved areas are not recommended due to the
potential for surface or irrigation water to infiltrate the pavement's subgrade and base course.
Either a subdrain, which collects excess irrigation water and transmits it to drainage
structures, or an impervious above-grade planter boxes should be used. In addition, where
landscaping is planned adjacent to the pavement, it is recommended that consideration be
given to providing a cutoff wall along the edge of the pavement that extends at least
12 inches below the base material.
7.19 Plan Review
7.19.1 Grading, shoring, and foundation plans should be reviewed by the Geotechnical Engineer prior
to finalization to verify that the plans have been prepared in substantial conformance with the
recommendations of this report and to provide additional analyses or recommendations.
Geocon Project No.T2719-22-01 -27- June 14,2016
LIMITATIONS AND UNIFORMITY OF CONDITIONS
1. The recommendations of this report pertain only to the site investigated and are based
upon the assumption that the soil conditions do not deviate from those disclosed in the
investigation. If any variations or undesirable conditions are encountered during construction,
or if the proposed construction will differ from that anticipated herein, Geocon should be
notified so that supplemental recommendations can be given. The evaluation or identification
of the potential presence of hazardous materials was not part of the scope of services provided
by Geocon.
2. This report is issued with the understanding that it is the responsibility of the owner, or of his
representative,to ensure that the information and recommendations contained herein are brought
to the attention of the architect and engineer for the project and incorporated into the plans, and
the necessary steps are taken to see that the contractor and subcontractors carry out such
recommendations in the field.
3. The findings of this report are valid as of the date of this report. However, changes in the
conditions of a property can occur with the passage of time, whether they are due to natural
processes or the works of man on this or adjacent properties.In addition,changes in applicable
or appropriate standards may occur, whether they result from legislation or the broadening of
knowledge. Accordingly,the findings of this report may be invalidated wholly or partially by
changes outside our control. Therefore,this report is subject to review and should not be relied
upon after a period of three years.
4. The firm that performed the geotechnical investigation for the project should be retained to
provide testing and observation services during construction to provide continuity of
geotechnical interpretation and to check that the recommendations presented for geotechnical
aspects of site development are incorporated during site grading,construction of improvements,
and excavation of foundations.If another geotechnical firm is selected to perform the testing and
observation services during construction operations, that firm should prepare a letter indicating
their intent to assume the responsibilities of project geotechnical engineer of record. A copy of
the letter should be provided to the regulatory agency for their records. In addition, that firm
should provide revised recommendations concerning the geotechnical aspects of the proposed
development, or a written acknowledgement of their concurrence with the recommendations
presented in our report. They should also perform additional analyses deemed necessary to
assume the role of Geotechnical Engineer of Record.
Geocon Project No.T2710-22-01 June 14,2016
LIST OF REFERENCES
1. American Concrete Institute,2011,Building Code Requirements for Structural Concrete,Report
by ACI Committee 318.
2. American Concrete Institute, 2008, Guide for Design and Construction of Concrete Parking
Lots,Report by ACI Committee 330.
3. Blake,T.F., 1998,LIQUEFY2,A Computer Program for the Estimation of Liquefaction of Soils,
Version 1.5.
4. California Building Standards Commission, 2013, California Building Code (CBQ, California
Code of Regulations Title 24,Part 2.
5. California Geological Survey (CGS), 2008, Guidelines for Evaluating and Mitigating Seismic
Hazards in California, Special Publication 117.
6. California Geological Survey (GCS), California Geomorphic Provinces, Note 36,
dated December 2002.
7. California Geological Survey(CGS),Information Warehouse: Regulatory Maps website for
Alquist-Priolo Earthquake Fault Zone Maps,
http://maps.conservation.ca.gov/cgs/informationwarehouse/index.html?map=regulatorymaps,
accessed April 6, 2016.
8. California Geological Survey (CGS), Probabilistic Seismic Hazards Mapping-Ground Motion
Page, 2003, CGS Website: www.conserv.ca.gov/cas/rghmZpshamap.
9. California Geological Survey,Seismic Shaking Hazards in California, Based on the USGS/CGS
Probabilistic Seismic Hazards Assessment (PSHA) Model, 2002 (revised
April 2003). 10% probability of being exceeded in 50 years;
http:Hredirect.conservation.ca.gov/ccgs/rghm/pshamap/pshamain.html.
10. California Department of Transportation(Caltrans),Division of Engineering Services,Materials
Engineering and Testing Services, Corrosion Guidelines, Version 2.0,
dated November,2012.
11. California Department of Water Resources, Water Data Library website,
www.water.ca.gov/waterdatalibrga/index.cfm, accessed June 2,2016.
12. Google Inc., Google Maps online mapping software, accessed June 2,2016.
13. Google Inc., Google Earth Pro,Version 7.1.2.2041, accessed June 2,2016.
14. Harden,D.R., California Geology,Prentice-Hall, Inc.,479 pp., 1998.
15. Jennings,Charles W.and Bryant,William A.,2010,Fault Activity Map of California, California
Division of Mines and Geology Map No. 6.
16. Kennedy, M.P., 1977, Recency and Character of Faulting Along the Elsinore Fault Zone in
Southern Riverside County, California, C.D.M.G. Special Report 131.
Geocon Project No.T2719-22-01 June 14,2016
LIST OF REFERENCES (CONTD.)
17. Legg, M. R., J. C. Borrero, and C. E. Synolakis, Evaluation of Tsunami Risk to Southern
California Coastal Cities, 2002 NEHRP Professional Fellowship Report, dated January 2003.
18. Mann,J.F., 1955,Geology of a Portion of the Elsinore Fault Zone, California, C.D.M.G. Special
report 43.
19. Morton, D. M. and Weber, F.H. Jr., 2003, Preliminary Geologic Map of the Elsinore 7.5'
Quadrangle, Riverside County, California, USGS Open-File Report 03-281, version 1.0, Scale
1:24,000.
20. Public Works Standards, Inc., 2015, Standard Specifications for Public Works Construction
"Greenbook,"Published by BNi Building News.
21. Rockwell T.K. and Lamar,D.L., 1986,Neotectonics of the Elsinore Fault, Southern California,
in Geological Society of America Guidebook,Neotectonics and Faulting in Southern California,
March 1986,pp. 149-208.
22. Riverside County Land Information System,
http://mmc.rivcoit.org/MMC_PublicNiewer.html?Viewer=MMC_Public
23. Terra Geosciences, 2015, Evaluation of Surface Fault Rupture Hazard, Elsinore View Mobile
Home Park Project, Assessor's Parcel Nos. 371-150-001 & -002 (4.51AC & 2.25 AC) and
371-090-001 & 002 (4.55 AC&2.27 AC), City of Lake Elsinore, Riverside County, California,
Project No. 152772-1,dated March 31.
24. Treiman, J., compiler, 1988, Fault Number 126d, Elsinore Fault Zone, Temecula Section, in
Quaternary Fault and Fold Database of the United States: U.S. Geological Survey website,
hlt 2:Hearthquakes.usas.gov/hazards/gfaults.
25. U.S. Geological Survey (USGS), Deaggregation of Seismic Hazard for PGA and 2 Periods of
Spectral Acceleration,2002,USGS Website:www.earthquake.usgs.gov/research/hazmaps.
26. U.S. Geological Survey (USGS), Interactive Fault Map, online at
http://earthquake.usgs.gov/hazards/qfaults/map/,accessed April 6,2016.
27. U.S. Geological Survey (USGS), U.S. Seismic Design Maps website,
hltp:Hearthquake.usgs.gov/designmaps/us/application", accessed online April 6,2016.
28. Weber F. H. 1977, Seismic Hazards Related to Geologic Factors, Elsinore and Chino Fault
Zones, Northwestern Riverside County, California, C.D.M.G. Open-File Report, 77-4 LA, 96
PP.
29. Woodford,A. O., Shelton,J.,Doehring,D.,and Morton,R., 1071,Pliocene-Pleistocene History
of the Perris Block, Southern California, Geological Society of America Bulletin, V. 82, pp
3421-3448, 18 Figures,dated December.
Geocon Project No.T2719-22-01 June 14,2016
Aerial Photographs
Riverside County Flood Control and Water Conservation District, 1960,Photo Numbers 46 and
47, Scale 1"=1,000', dated September 6.
Riverside County Flood Control and Water Conservation District, 1974, Photo Numbers 724
and 725, Scale 1"=2,000', dated June 20.
Riverside County Flood Control and Water Conservation District, 1980 Photo Numbers 754 and
755, Scale 1"=2,000', dated May 4.
Riverside County Flood Control and Water Conservation District, 1990, Photo Numbers 14-10
and 14-11, Scale 1"=2,000",dated January 22.
Riverside County Flood Control and Water Conservation District, 2000, Photo Numbers 14-9
and 14-10, Scale 1"=2,000', dated March 18.
Riverside County Flood Control and Water Conservation District, 2005, Photo Numbers 14-9
and 14-10, Scale 1"=2,000', dated April 13.
Riverside County Flood Control and Water Conservation District, 2010, Photo Numbers 14-9
and 14-10, Scale 1"=2,000', dated April 2.
Geocon Project No.T2719-22-01 June 14,2016
n u
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Y
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Y
+ n
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Lake 0 �t•s��• : .•_z:..,.:•t:
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9
o
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e
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Project
:• . Site ` r...�..
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WS
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1 INCH= 1500 FEET
(SCALE IS APPROXIMATE)
SOURCE: CGS, 1980, Elsinore AP Quadrangle.
VIC INITY MAP
GE O C O LAKE RESO RTAPARTMENTS
W E S T, I N C.
E. O F G RAND AVE. AT VAIL ST.
GEOTECHNICAL ENVIRONMENTAL MATERIALS LAKE ELSINO RE, CALIFORNIA
41571 CORNING PLACE,SUITE 101,MURRIETA,CA 92562-7065
PHONE 951-304-2300 FAX 951-304-2392
AMO I I J r JUNE, 2016 PROJECT NO.T2719-22-01 FIG. 1
+� t_ LEGEND
N I J��. + - +, ao,uNrts +�„ —�, B5 ,t t LDINc a --? Geologic Contact
0 +; B euILDwG 1 \\``� + °�APARTMENTS J +. �°� + 1 — �� asroRr (queried where uncertain)
J +- 36 UNITS 3 __ �-f
3 `ORY �\,i f +' I Pow UILDING 3 " 9 rn TMENTS
APARTMENTS +; °! co 36 UNITS f u " 1 BIZ
+, 3 STORY �G t afu Artificial Fill - undoc.
_ + ARTMENTS
BIDC 2 �
W P 4 1 +P \ +�„ PAD=,yB6 ♦ +, 1 P;'11 ,I QI Lacustrine Deposits
J +
�< .. _ +'— � �� +. � � \` o' u , _ + � '�� rC t � Qal Alluvium
Qps Pauba Formation
s �s +; RA + Approx. Boring Location
S
\
+(8 I �ks� ' � I +� +' I \� � 1 1 1 � \ �� ",ram � I���
I +. N 1 \
+ \y f� ,,I.\�
t SET BACK'PO \ + +�
\ N J
X J
STORY.. —
OWNER AND APPLICANT: OPEN SPACE MAINTENANCE Co �� 1 \\ +\ 1
5TEVE GALKZ OPEN SPACE WLL BE M4NTANEC By PROPERTY MANAGEMENT, Z O \ +� +ea
31938 TELECUU PIANY/A369 N Tr
TEYECULA.CA 92592 AERIAL TOPOGRAPHY
PHONE: 951)297-6120
EMAILOSTEVFGALVEZ.CON THE TOPOGRA W IS B SED ON FLOWN TOPOGRAP C W"NC 2008 AND fElD VERFU IN2DIA
ENGINEER AND EXHIBIT PREPARER: FLOOD PLAIN DESIGNATION
GRANT BECHLUND CIVIL ENGINEERING THIS SITE IS IN FLOOD ZONE•AE•AND Y-TEMA PANEL 06065C 2039G (�
30811 GARBANI ROAD THIS PROJECT IS IN THE SANTA AM WATERSHED DRAINAGE AREA. +
WI ,
NCHESTER.CA TH 92596 IS LAND IS SUBJECT TO OVERFLOW AND INUNDATION OR FLOOD HAZARD. a• ' ` 1�� \
PHONE 951 288-0601 \1`
t
E1ADL-cRAHTBECKLUNDOGMALCOM LEGEND — — — � � —+
ASSESSOR'S PARCEL NUMBER: +
371-150-ODI k 002.371-090-001 A:D02 ® STORY DRAIN LINE
LEGAL DESCRIPTION: INLET
BEING A PORTION OF SECTION 19.TOWNSHIP 6 SOUTH,RANGE 4 WEST, OUANnTY ESTIMATE �T '�
SAN BFRNARDINO BASE AND MERIDIAN. TOTAL CUT: )DM=C.Y. FILL:X70000(C.Y. i' I �J 1\VI ���.
GENERAL NOTES THIS PROJECT WILL BE A'BALANCED EARi1FAORM BESM
WITH AID EXPORT OR IMPORT OF GRADING WTMiL W E S T, I N C.
DRAINAGE: OElFL6\OR OF SRE Tu VEISERATE D95NO DMKI PATTON&DEA1OPMX TALL DRMN TO
s m QJALR BASKS ND UJOi 11SWORE.
GRADING: GRADING WILL CONFORM TO THAT SHOWN ON THIS PLOT PUN. �o / ENVIRONMENTAL GEOTECHNICAL MATERIALS
STREETS: AU STREETS NRIN THIS TRACT VU BE CO161RUCIm PER THE OTT OF LA F151AORE STANDARDS �°'
LIGHRNG: ALL LIGHTING wIi caKORM ro OA➢IFR 8.64 LIGHT PO1111IION CODE NAL
PREPARED: JANUARF 2016. 1 41571 CORNING PLACE,SUITE 101,MURRIETA,CALIFORNIA 92562
�6fQN 9E6C6100001 III9BA 91NS AE OD 6 96�10 WIF7AD01 OROIQ Q000'A NV1iDS PHONE (951)304-2300 - FAX (951)304-2392
DEVEIOPYWELE R PROPERTY.DaSTS ON WILL COR!W OF FOUR BUILDINGS MM RENTAL APARTMENT DWELLING UNITS ND 1 p WILL BE PROCESSED AS A PLOT PLAN.
PT
GEOTECHNICAL MAP
LAKE RESORT APARTMENTS
E. OF GRAND AVE.AT VAIL ST.
0 100, 200' LAKE ELSINORE, CALIFORNIA
JUNE,2016 1 PROJECT NO.T2719-22-01 FIG.2
Legend I ,
FSIFC4,
Qw Very young wash deposits
Qf Very young alluvial fan deposits
C
QI Very young lacustrine deposits
Qyfa Young alluvial fan deposits
Qyfla Young alluvial fan deposits, unit 1
Qyv,, Young alluvial valley deposits
Qofg Old alluvial fan deposits
Qpfs Pauba Formation, sandstone member ,
"N I N, "t.
T ail"
P
Kgd Granodiorite
Khg Heterogeneous granitic rocks
Mzu Undifferentiated metasedimentary rocks
Mzq Quartz-rich rocks
Mzp Phyllite 01
%
All
Project
Site
is nd Village
01
...........
0*4
4.�
NOT TO SCALE
SOURCE: Morton, D.M. and F.H. Weber, Jr., 2003, Preliminary Geologic Map of the Elsinore 7.5'
Quadrangle, Riverside County, California, v. 1.0, USGS OFR 03-281.
REG 10 NAL G EO LO G IC MAP
GEOCON LAKE RESO RTAPARTMENTS
W E S T, I N C. <<P E. 0 F G RAND AVE. AT VAIL ST
GEOTECHNICAL ENVIRONMENTAL MATERIALS LAKE ELSINO RE, C ALIFO RNIA
41571 CORNING PLACE,SUITE 101,MURRIETA,CA 92562-7065
PHONE 951-304-2300 FAX 951-304-2392
AMO I I JUNE, 2016 PROJECT NO.T2719-22-01 FIG. 3
Client:Lake Resort Apartments
OF)
File No.:T2719-22-01
Boring: 1
GEOCON
EMPIRICAL ESTIMATION OF LIQUEFACTION POTENTIAL
DESIGN EARTHQUAKE
NCEER(1996)METHOD By Thomas F.Blake(1994-1996)
EARTHQUAKE INFORMATION: ENERGY&ROD CORRECTIONS:
Earthquake Magnitude: 6.89 Energy Correction CE for N60: 1.25
Peak Horiz.Acceleration PGAM(g): 0.932 Rod Len.Corr.CR 0-no or 1-yes): 1.0
2/3 PGAM(g): 0.622 Bore Dia.Corr.(CB): 1.15
Calculated Ma .Wt .Factor: 0.809 Sampler Corr.(CS): 1.20
Historic High Groundwater: 5.0 Use Ksi ma 0 or 1): 1.0
Groundwater Depth During Exploration: 26.5
LIQUEFACTION CALCULATIONS:
nit Wt.Water (pc : 62.4
Depth to Total Unit Water FIELD Depth of Liq.Sus. -200 Est.Dr CN Corrected Eff.Unit Resist. rd Induced Liquefac.
Base(ft) Wt.(pcf) (0 or 1) SPT(N) SPT(ft) (0 or 1) (%) (%) Factor (N1)60 Wt.(psf) CRR Factor CSR Safe.Fact.
1.0 125.0 0 19.0 5.0 1 95 2.000 49.2 125.0 Infin. 0.998 0.326
2.0 125.0 0 19.0 5.0 1 0 95 2.000 49.2 125.0 nfin. 0.993 0.325
3.0 125.0 0 19.0 5.0 1 0 95 2.000 49.2 125.0 Infin. 0.989 0.323
4.0 125.0 0 19.0 5.0 1 0 95 2.000 49.2 125.0 Infin. 0.984 0.322
5.0 125.0 1 19.0 5.0 1 0 95 1.927 47.4 62.6 Infin. 0.979 0.339 Non-Liq.
6.0 125.0 1 19.0 5.0 1 0 95 1.743 42.8 62.6 Infin. 0.975 0.369 Non-Liq.
7.0 125.0 1 12.0 7.5 1 36 73 1.603 31.9 62.6 Infin. 0.970 0.392 Non-Liq.
8.0 125.0 1 12.0 7.5 1 36 73 1.492 30.2 62.6 Infin. 0.966 0.411 Non-Liq.
9.0 125.0 1 12.0 7.5 1 1 36 73 1.402 28.8 62.6 0.375 0.961 0.427 0.88
10.0 125.0 1 12.0 7.5 1 36 73 1.326 27.6 62.6 0.338 1 0.957 0.440 0.77
11.0 125.0 1 12.0 7.5 1 36 73 1.261 26.6 62.6 0.315 0.952 0.450 0.70
12.0 125.0 1 6.0 12.5 1 36 49 1.205 16.4 62.6 0.178 0.947 0.459 0.39
13.0 125.0 1 6.0 12.5 1 36 49 1.156 16.0 62.6 0.174 0.943 0.466 0.37
14.0 125.0 1 6.0 12.5 1 36 49 1.112 15.6 62.6 0.170 0.938 0.473 0.36
15.0 125.0 1 10.0 17.5 1 42 60 1.073 22.8 62.6 0.253 0.934 0.478 0.53
16.0 125.0 1 10.0 17.5 1 42 60 1.038 22.3 62.6 0.246 0.929 0.482 0.51
17.0 125.0 1 1 10.0 17.5 1 42 60 1.006 21.8 62.6 0.240 0.925 0.486 0.49
18.0 125.0 1 10.0 17.5 1 42 60 0.977 21.4 62.6 0.235 0.920 0.489 0.48
19.0 125.0 1 10.0 17.5 1 42 60 0.950 21.0 62.6 0.230 1 0.915 0.491 1 0.47
20.0 125.0 1 10.0 17.5 1 42 60 0.926 20.7 62.6 0.226 0.911 0.493 0.46
21.0 125.0 1 10.0 17.5 1 42 60 0.903 20.3 62.6 0.222 0.906 0.495 0.45
22.0 125.0 1 10.0 17.5 1 42 60 0.881 20.0 62.6 0.218 0.902 0.496 0.44
23.0 125.0 1 7.0 22.5 1 42 48 0.862 16.7 62.6 0.181 0.897 0.497 0.36
24.0 125.0 1 7.0 22.5 1 42 48 0.843 16.4 62.6 0.179 0.893 0.498 0.36
25.0 125.0 1 22.0 27.5 1 35 82 0.826 37.7 62.6 Infin. 0.888 0.498 Non-Liq.
26.0 125.0 1 1 22.0 27.5 1 1 35 1 82 0.809 37.1 62.6 Infin. 0.883 0.498 Non-Liq.
27.0 125.0 1 22.0 27.5 1 35 82 0.798 36.6 62.6 Infin. 0.879 0.498 Non-Liq.
28.0 125.0 1 22.0 27.5 1 35 82 0.790 36.4 62.6 Infin. 0.874 0.498 Non-Liq.
29.0 125.0 1 22.0 27.5 1 35 82 0.783 36.1 62.6 Infin. 0.870 0.498 Non-Liq.
30.0 125.0 1 22.0 27.5 1 35 82 0.776 35.8 62.6 Infin. 0.865 0.497 Non-Liq.
31.0 125.0 1 22.0 27.5 1 35 82 0.769 35.6 62.6 Infin. 0.861 0.497 Non-Liq.
32.0 125.0 1 22.0 27.5 1 35 82 0.762 35.3 62.6 Infin. 0.856 0.496 Non-Liq.
33.0 125.0 1 9.0 32.5 1 39 50 0.756 18.7 62.6 0.201 0.851 0.495 0.41
34.0 125.0 1 9.0 32.5 1 39 50 0.749 18.6 62.6 0.200 0.847 0.494 0.41
35.0 125.0 1 1 26.0 37.5 1 1 38 83 0.743 40.3 62.6 Infin. 0.842 0.493 Non-Liq.
36.0 125.0 1 26.0 37.5 1 38 1 83 0.737 40.1 62.6 Infin. 1 0.838 0.491 1 Non-Liq.
37.0 125.0 1 26.0 37.5 1 38 83 0.731 39.8 62.6 Infin. 0.833 0.490 Non-Liq.
38.0 125.0 1 26.0 37.5 1 38 83 0.725 39.5 62.6 Infin. 0.829 0.489 Non-Liq.
39.0 125.0 1 26.0 37.5 1 38 83 0.720 39.3 62.6 Infin. 0.824 0.487 Non-Liq.
40.0 125.0 1 22.0 40.0 1 40 75 0.714 1 34.1 62.6 Infin. 0.819 0.486 Non-Liq.
41.0 125.0 1 22.0 40.0 1 40 75 0.709 33.9 62.6 Infin. 0.815 0.484 Non-Liq.
42.0 125.0 1 32.0 42.5 1 0 89 0.703 38.8 62.6 Infin. 0.810 0.482 Non-Liq.
43.0 125.0 1 32.0 42.5 1 0 89 0.698 38.5 62.6 Infin. 0.806 0.481 Non-Liq.
44.0 125.0 1 1 32.0 42.5 1 1 0 89 0.693 38.3 62.6 Infin. 0.801 0.479 Non-Liq.
45.0 125.0 1 32.0 42.5 1 1 0 1 89 0.688 38.0 62.6 Infin. 1 0.797 1 0.477 1 Non-Liq.
46.0 125.0 1 32.0 42.5 1 0 89 0.683 37.7 62.6 Infin. 0.792 0.475 Non-Liq.
47.0 125.0 1 62.0 47.5 1 0 120 0.679 72.6 62.6 Infin. 0.787 0.473 Non-Liq.
48.0 125.0 1 62.0 47.5 1 0 120 0.674 72.1 62.6 Infin. 0.783 0.471 Non-Liq.
49.0 125.0 1 62.0 47.5 1 0 120 0.669 71.6 62.6 Infin. 0.778 0.469 Non-Liq.
50.0 125.0 1 62.0 47.5 1 0 120 1 0.665 71.1 1 62.6 Infin. 0.774 I 0.467 Non-Liq.
Figure 4
Client: Lake Resort Apartments
File No. : T2719-22-01
<olw) Boring : 1
GEOCON
LIQUEFACTION SETTLEMENT ANALYSIS
DESIGN EARTHQUAKE
(SATURATED SAND AT INITIAL LIQUEFACTION CONDITION)
NCEER(1996)METHOD
EARTHQUAKE INFORMATION:
Earthquake Magnitude: 6.89
PGAM(g): 0.932
2/3 PGAM(g): 0.62
Calculated Mag.Wtg.Factor: 0.809
Historic High Groundwater: 5.0
Groundwater Exploration: 26.5
DEPTH BL W WET T TAL EFFE T REL. ADJU T LI UEFA TI N Volumetric E .
TO COUNT DENSITY STRESS STRESS DEN. BLOWS SAFETY Strain SETTLE.
BASE N (PCF) O(TSF) O'(TSF) Dr(%) (N1)60 av 6o FACTOR [el.1 (%) Pe(in.)
1 19 125 0.031 0.031 95 49 0.404 0.00 Grading
2 19 125 0.094 0.094 95 49 0.404 0.00 Grading
3 19 125 0.156 0.156 95 49 0.404 0.00 Grading
4 19 125 0.219 0.219 95 49 0.404 0.00 Grading
5 19 125 0.281 0.266 95 47 0.428 Non-Liq. 0.00 Grading
6 19 125 0.344 0.297 95 43 0.468 Non-Liq. 0.00 Grading
7 12 125 0.406 0.328 73 32 0.500 Non-Liq. 0.00 0.00
8 12 125 0.469 0.360 73 30 0.527 Non-Liq. 0.00 0.00
9 12 125 0.531 0.391 73 29 0.549 0.88 0.75 0.09
10 12 125 0.594 0.422 73 28 0.568 0.77 0.75 0.09
11 12 125 0.656 0.453 73 27 0.585 0.70 1.10 0.13
12 6 125 0.719 0.485 49 16 0.599 0.39 1.70 0.20
13 6 125 0.781 0.516 49 16 0.612 0.37 1.70 0.20
14 6 125 0.844 0.547 49 16 0.623 0.36 1.70 0.20
15 10 125 0.906 0.579 60 23 0.633 0.53 1.30 0.16
16 10 125 0.969 0.610 60 22 0.642 0.51 1.40 0.17
17 10 125 1.031 0.641 60 22 0.650 0.49 1.40 0.17
18 10 125 1.094 0.673 60 21 0.657 0.48 1.40 0.17
19 10 125 1.156 0.704 60 21 0.664 0.47 1.40 0.17
20 10 125 1.219 0.735 60 21 0.670 0.46 1.40 0.17
21 10 125 1.281 0.766 60 20 0.675 0.45 1.40 0.17
22 10 125 1.344 0.798 60 20 0.681 0.44 1.40 0.17
23 7 125 1.406 0.829 48 17 0.685 0.36 1.70 0.20
24 7 125 1.469 0.860 48 16 0.690 0.36 1.70 0.20
25 22 125 1.531 0.892 82 38 0.694 Non-Liq. 0.00 0.00
26 22 125 1.594 0.923 82 37 0.698 Non-Liq. 0.00 0.00
27 22 125 1.656 0.954 82 37 0.701 Non-Liq. 0.00 0.00
28 22 125 1.719 0.986 82 36 0.705 Non-Liq. 0.00 0.00
29 22 125 1.781 1.017 82 36 0.708 Non-Liq. 0.00 0.00
30 22 125 1.844 1.048 82 36 0.711 Non-Liq. 0.00 0.00
31 22 125 1.906 1.079 82 36 0.714 Non-Liq. 0.00 0.00
32 22 125 1.969 1.111 82 35 0.716 Non-Liq. 0.00 0.00
33 9 125 2.031 1.142 50 19 0.719 0.41 1.60 0.19
34 9 125 2.094 1.173 50 19 0.721 0.41 1.60 0.19
35 26 125 2.156 1.205 83 40 0.723 Non-Liq. 0.00 0.00
36 26 125 2.219 1.236 83 40 0.725 Non-Liq. 0.00 0.00
37 26 125 2.281 1.267 83 40 0.727 Non-Liq. 0.00 0.00
38 26 125 2.344 1.299 83 40 0.729 Non-Liq. 0.00 0.00
39 26 125 2.406 1.330 83 39 0.731 Non-Liq. 0.00 0.00
40 22 125 2.469 1.361 75 34 0.733 Non-Liq. 0.00 0.00
41 22 125 2.531 1.392 75 34 0.735 Non-Liq. 0.00 0.00
42 32 125 2.594 1.424 89 39 0.736 Non-Liq. 0.00 0.00
43 32 125 2.656 1.455 89 39 0.738 Non-Liq. 0.00 0.00
44 32 125 2.719 1.486 89 38 0.739 Non-Liq. 0.00 0.00
45 32 125 2.781 1.518 89 38 0.740 Non-Liq. 0.00 0.00
46 32 125 2.844 1.549 89 38 0.742 Non-Liq. 0.00 0.00
47 62 125 2.906 1.580 120 73 0.743 Non-Liq. 0.00 0.00
48 62 125 2.969 1.612 120 72 0.744 Non-Liq. 0.00 0.00
49 62 125 3.031 1.643 120 72 0.746 Non-Liq. 0.00 0.00
50 62 125 3.094 1.674 120 71 0.747 Non-Liq. 0.00 0.00
TOTAL SETTLEMENT= 3.0 INCHES
Figure 5
Client: Lake Resort Apartments
File No.: T2719-22-01
4R)
Boring: 1
GEOCON
EMPIRICAL ESTIMATION OF LIQUEFACTION POTENTIAL
MAXIMUM CONSIDERED EARTHQUAKE
WEER(1996)METHOD By Thomas F.Blake(1994-1996)
EARTHQUAKE INFORMATION: ENERGY&ROD CORRECTIONS:
Earth uake Ma nitude: 7.03 Ener Correction CE for N60: 1.25
Peak Horiz.Acceleration PGAM(g): 0.932 Rod Len.Corr.CR 0-no or 1-yes: 1.0
Calculated Ma .Wt .Factor: 0.851 Bore Dia.Corr.(CB): 1.15
Historic High Groundwater: 5.0 Sampler Corr.(CS): 1.20
Groundwater Depth During Exploration: 26.5 Use Ksi ma 0 or 1): 1.0
LIQUEFACTION CALCULATIONS:
nit Wt.Water pc
Depth to Total Unit Water FIELD Depth of Liq.Sus. -200 Est.Dr CN Corrected Eff.Unit Resist. rd Induced Liquefac.
Base(ft) Wt.(pcf) (0 or 1) SPT(N) SPT(ft) (0 or 1) (%) (%) Factor (N1)60 Wt.(psf) CRR Factor CSR Safe.Fact.
1.0 125.0 0 19.0 5.0 1 95 2.000 49.2 125.0 Infin. 0.998 0.515 --
2.0 125.0 0 19.0 5.0 1 95 2.000 49.2 125.0 Infin. 0.993 0.512 --
3.0 125.0 0 19.0 5.0 1 95 2.000 49.2 125.0 Infin. 0.989 0.510 --
4.0 125.0 0 19.0 5.0 1 95 2.000 49.2 125.0 Infin. 0.984 0.508 --
5.0 125.0 1 19.0 5.0 1 95 1.927 47.4 62.6 Infin. 0.979 0.535 Non-Liq.
6.0 125.0 1 19.0 5.0 1 95 1.743 42.8 62.6 Infin. 0.975 0.582 Non-Liq.
7.0 125.0 1 12.0 7.5 1 36 73 1.603 31.9 62.6 Infin. 0.970 0.619 Non-Liq.
8.0 125.0 1 12.0 7.5 1 36 73 1.492 30.2 62.6 Infin. 0.966 0.649 Non-Liq.
9.0 125.0 1 12.0 7.5 1 1 36 73 1 1.402 28.8 62.6 0.375 1 0.961 0.674 0.56
10.0 125.0 1 12.0 7.5 1 36 73 1.326 27.6 62.6 0.338 0.957 0.694 0.49
11.0 125.0 1 12.0 7.5 1 36 73 1.261 26.6 62.6 0.315 0.952 0.711 0.44
12.0 125.0 1 6.0 12.5 1 36 49 1.205 16.4 62.6 0.178 0.947 0.725 0.25
13.0 125.0 1 6.0 12.5 1 36 49 1.156 16.0 62.6 0.174 0.943 0.736 0.24
14.0 125.0 1 6.0 12.5 1 36 49 1.112 15.6 62.6 0.170 0.938 0.746 0.23
15.0 125.0 1 10.0 17.5 1 42 60 1.073 22.8 62.6 0.253 0.934 0.754 0.34
16.0 125.0 1 10.0 17.5 1 42 60 1.038 22.3 62.6 0.246 0.929 0.761 0.32
17.0 125.0 1 10.0 17.5 1 1 42 60 1 1.006 21.8 62.6 0.240 0.925 0.767 0.31
18.0 125.0 1 10.0 17.5 1 42 60 0.977 21.4 62.6 0.235 1 0.920 0.772 0.30
19.0 125.0 1 10.0 17.5 1 42 60 0.950 21.0 62.6 0.230 0.915 0.776 0.30
20.0 125.0 1 10.0 17.5 1 42 60 0.926 20.7 62.6 0.226 0.911 0.779 0.29
21.0 125.0 1 10.0 17.5 1 42 60 0.903 20.3 62.6 0.222 0.906 0.781 0.28
22.0 125.0 1 10.0 17.5 1 42 60 0.881 20.0 62.6 0.218 0.902 0.783 0.28
23.0 125.0 1 7.0 22.5 1 42 48 0.862 16.7 62.6 0.181 0.897 0.785 1 0.23
24.0 125.0 1 7.0 22.5 1 42 48 0.843 16.4 62.6 0.179 0.893 0.786 0.23
25.0 125.0 1 22.0 27.5 1 35 82 0.826 37.7 62.6 Infin. 0.888 0.787 Non-Liq.
26.0 125.0 1 22.0 27.5 1 1 35 82 0.809 37.1 62.6 Infin. 0.883 0.787 Non-Liq.
27.0 125.0 1 22.0 27.5 1 35 82 0.798 36.6 62.6 Infin. 0.879 0.787 Non-Liq.
28.0 125.0 1 22.0 27.5 1 35 82 0.790 36.4 62.6 Infin. 0.874 0.786 Non-Liq.
29.0 125.0 1 22.0 27.5 1 35 82 0.783 36.1 62.6 Infin. 0.870 0.786 Non-Liq.
30.0 125.0 1 22.0 27.5 1 35 82 0.776 35.8 62.6 Infin. 0.865 0.785 Non-Liq.
31.0 125.0 1 22.0 27.5 1 35 82 0.769 35.6 62.6 Infin. 0.861 1 0.784 Non-Liq.
32.0 125.0 1 22.0 27.5 1 35 82 0.762 35.3 62.6 Infin. 0.856 0.783 Non-Liq.
33.0 125.0 1 9.0 32.5 1 39 50 0.756 18.7 62.6 0.201 0.851 0.781 0.26
34.0 125.0 1 9.0 32.5 1 1 39 50 0.749 18.6 62.6 0.200 0.847 0.779 0.26
35.0 125.0 1 26.0 37.5 1 38 83 0.743 40.3 1 62.6 Infin. 0.842 0.778 Non-Liq.
36.0 125.0 1 26.0 37.5 1 38 83 0.737 40.1 62.6 Infin. 0.838 0.776 Non-Liq.
37.0 125.0 1 26.0 37.5 1 38 83 0.731 39.8 62.6 Infin. 0.833 0.774 Non-Liq.
38.0 125.0 1 26.0 37.5 1 38 83 0.725 39.5 62.6 Infin. 0.829 0.771 Non-Liq.
39.0 125.0 1 26.0 37.5 1 38 83 0.720 39.3 62.6 Infin. 0.824 0.769 Non-Liq.
40.0 125.0 1 22.0 40.0 1 40 75 0.714 34.1 62.6 Infin. 0.819 0.767 Non-Liq.
41.0 125.0 1 22.0 40.0 1 40 75 0.709 33.9 62.6 Infin. 0.815 0.764 Non-Liq.
42.0 125.0 1 32.0 42.5 1 1 89 1 0.703 38.8 62.6 Infin. 0.810 0.761 Non-Liq.
43.0 125.0 1 32.0 42.5 1 89 1 0.698 1 38.5 62.6 Infin. 0.806 0.759 Non-Liq.
44.0 125.0 1 32.0 42.5 1 89 0.693 1 38.3 62.6 Infin. 0.801 0.756 Non-Liq.
45.0 125.0 1 32.0 42.5 1 89 0.688 38.0 62.6 Infin. 0.797 0.753 Non-Liq.
46.0 125.0 1 32.0 42.5 1 89 0.683 37.7 62.6 Infin. 0.792 0.750 Non-Liq.
47.0 125.0 1 62.0 47.5 1 120 0.679 72.6 62.6 Infin. 0.787 0.747 Non-Liq.
48.0 125.0 1 62.0 47.5 1 120 0.674 72.1 62.6 Infin. 0.783 0.744 Non-Liq.
49.0 125.0 1 62.0 47.5 1 120 0.669 71.6 62.6 Infin. 0.778 0.741 Non-Liq.
50.0 125.0 1 62.0 J 7.5 1 120 0.665 71.1 62.6 Infin. 0.774 0.737 III Non-Liq.
Figure 6
Client: Lake Resort Apartments
<7>1
File No. : T2719-22-01
Boring : 1
GEOCON
LIQUEFACTION SETTLEMENT ANALYSIS
MAXIMUM CONSIDERED EARTHQUAKE
(SATURATED SAND AT INITIAL LIQUEFACTION CONDITION)
NCEER(1996)METHOD
EARTHQUAKE INFORMATION:
Earthquake Magnitude: 7.03
PGAM(g): 0.932
Calculated Mag.Wtg.Factor: 0.851
Historic High Groundwater: 5.0
Groundwater Exploration: 26.5
DEPTH BL W WET TOTAL EFFECT REL. ADJUST LIQUEFACTI N Volumetric EQ.
TO COUNT DENSITY STRESS STRESS DEN. BLOWS SAFETY Strain SETTLE.
BASE N (PCF) O(TSF) O'(TSF) Dr(%) (N1)60 av 6o FACTOR [el.) (%) Pe(in.)
1 19 125 0.031 0.031 95 49 0.606 0.00 Grading
2 19 125 0.094 0.094 95 49 0.606 0.00 Grading
3 19 125 0.156 0.156 95 49 0.606 0.00 Grading
4 19 125 0.219 0.219 95 49 0.606 0.00 Grading
5 19 125 0.281 0.266 95 47 0.641 Non-Liq. 0.00 Grading
6 19 125 0.344 0.297 95 43 0.701 Non-Liq. 0.00 Grading
7 12 125 0.406 0.328 73 32 0.750 Non-Liq. 0.00 0.00
8 12 125 0.469 0.360 73 30 0.790 Non-Liq. 0.00 0.00
9 12 125 0.531 0.391 73 29 0.823 0.56 0.75 0.09
10 12 125 0.594 0.422 73 28 0.852 0.49 0.75 0.09
11 12 125 0.656 0.453 73 27 0.877 0.44 1.10 0.13
12 6 125 0.719 0.485 49 16 0.898 0.25 1.70 0.20
13 6 125 0.781 0.516 49 16 0.917 0.24 1.70 0.20
14 6 125 0.844 0.547 49 16 0.934 0.23 1.70 0.20
15 10 125 0.906 0.579 60 23 0.949 0.34 1.30 0.16
16 10 125 0.969 0.610 60 22 0.962 0.32 1.40 0.17
17 10 125 1.031 0.641 60 22 0.974 0.31 1.40 0.17
18 10 125 1.094 0.673 60 21 0.985 0.30 1.40 0.17
19 10 125 1.156 0.704 60 21 0.995 0.30 1.40 0.17
20 10 125 1.219 0.735 60 21 1.004 0.29 1.40 0.17
21 10 125 1.281 0.766 60 20 1.013 0.28 1.40 0.17
22 10 125 1.344 0.798 60 20 1.020 0.28 1.40 0.17
23 7 125 1.406 0.829 48 17 1.028 0.23 1.70 0.20
24 7 125 1.469 0.860 48 16 1.034 0.23 1.70 0.20
25 22 125 1.531 0.892 82 38 1.040 Non-Liq. 0.00 0.00
26 22 125 1.594 0.923 82 37 1.046 Non-Liq. 0.00 0.00
27 22 125 1.656 0.954 82 37 1.051 Non-Liq. 0.00 0.00
28 22 125 1.719 0.986 82 36 1.056 Non-Liq. 0.00 0.00
29 22 125 1.781 1.017 82 36 1.061 Non-Liq. 0.00 0.00
30 22 125 1.844 1.048 82 36 1.066 Non-Liq. 0.00 0.00
31 22 125 1.906 1.079 82 36 1.070 Non-Liq. 0.00 0.00
32 22 125 1.969 1.111 82 35 1.074 Non-Liq. 0.00 0.00
33 9 125 2.031 1.142 50 19 1.077 0.26 1.60 0.19
34 9 125 2.094 1.173 50 19 1.081 0.26 1.60 0.19
35 26 125 2.156 1.205 83 40 1.084 Non-Liq. 0.00 0.00
36 26 125 2.219 1.236 83 40 1.088 Non-Liq. 0.00 0.00
37 26 125 2.281 1.267 83 40 1.091 Non-Liq. 0.00 0.00
38 26 125 2.344 1.299 83 40 1.093 Non-Liq. 0.00 0.00
39 26 125 2.406 1.330 83 39 1.096 Non-Liq. 0.00 0.00
40 22 125 2.469 1.361 75 34 1.099 Non-Liq. 0.00 0.00
41 22 125 2.531 1.392 75 34 1.101 Non-Liq. 0.00 0.00
42 32 125 2.594 1.424 89 39 1.104 Non-Liq. 0.00 0.00
43 32 125 2.656 1.455 89 39 1.106 Non-Liq. 0.00 0.00
44 32 125 2.719 1.486 89 38 1.108 Non-Liq. 0.00 0.00
45 32 125 2.781 1.518 89 38 1.110 Non-Liq. 0.00 0.00
46 32 125 2.844 1.549 89 38 1.112 Non-Liq. 0.00 0.00
47 62 125 2.906 1.580 120 73 1.114 Non-Liq. 0.00 0.00
48 62 125 2.969 1.612 120 72 1.116 Non-Liq. 0.00 0.00
49 62 125 3.031 1.643 120 72 1.118 Non-Liq. 0.00 0.00
50 62 125 3.094 1.674 120 71 1.119 Non-Liq. 0.00 0.00
TOTAL SETTLEMENT= 3.0 INCHES
Figure 7
GROUND SURFACE
PROPERLY
COMPACTED
BACKFILL
/\WATERPROOF
WALL
RETAINING
WALL
°d a ° a p a 3/4"CRUSHED
P d °d 'da ad ROCK
dd m d P.d
d
^a a a
an a°
1W as H
q .� fi FILTER FABRIC ENVELOPE
1 4 MIRAFI 140N OR EQUIVALENT
a an
9 _ ddd ga..
-a a' d-. 'dJ 2/3 H 4"DIA.PERFORATED ABS
4 a ..I OR ADS PIPE-EXTEND TO
DRAINAGE SYSTEM
a d+
Ia �
° a .` 1
IQ
L� q •.
FOUNDATION
°O 40 da
NO SCALE
GE O,C,ON QW)
RETAINING WALL DRAIN DETAIL 1
w E S T, I N C. LAKE RESORT APARTMENTS
ENVIRONMENTAL GEOTECHNICAL MATERIALS E. OF GRAND AVE.AT VAIL ST.
41571 CORNING PLACE,SUITE 101,MURRIETA,CA 92562 LAKE ELSINORE, CALIFORNIA
PHONE (951)304-2300 - FAX (951)304-2392
Drafted by: RDG Checked by: HHD JUNE,2016 PROJECT NO.T2719-22-01 FIG.8
GROUND SURFACE
18"
PROPERLY
COMPACTED
BACKFILL
RETAINING DRAINAGE PANEL(J-DRAIN 1000
WALL OR EQUIVALENT)
WATER PROOFING
BY ARCHITECT
3/4"CRUSHED ROCK
(1 CU.FT./FT.)
X FILTER FABRIC ENVELOPE
;i OR BURLAP ROCK-POCKET
a
APPROVED PIPE EXTENDED TO
SUBDRAIN
�—TO SUBDRA�N j\�j\�j
FOUNDATION
4O dO 40
NO SCALE
GE OC ON 4Pw
RETAINING WALL DRAIN DETAIL 2
w E S T, I N C. LAKE RESORT APARTMENTS
ENVIRONMENTAL GEOTECHNICAL MATERIALS E. OF GRAND AVE.AT VAIL ST.
41571 CORNING PLACE,SUITE 101,MURRIETA,CA 92562 LAKE ELSINORE, CALIFORNIA
PHONE (951)304-2300 - FAX (951)304-2392
Drafted by: RDG Checked by: HHD JUNE,2016 7 PROJECT NO.T2719-22-01 FIG.9
APPENDIX A
�
APPENDIX A
EXPLORATORY EXCAVATIONS
We performed the field investigation on May 12, 2016. Our subsurface exploration consisted of
excavating six geotechnical borings. The borings were excavated with an 8-inch hollow-stem auger
drill to a maximum depth of 51.5 feet. Bulk samples of disturbed soils and ring samples of in-situ soils
were transported to our laboratory for testing.
We obtained soil samples during our subsurface exploration from the borings using a California
sampler. The sampler is composed of steel and is driven to obtain relatively undisturbed samples.
The California sampler has an inside diameter of 2.5 inches and an outside diameter of 3 inches.Rings
are placed inside the sampler that are 2.4 inches in diameter and 1 inch in height. We obtained
ring samples at appropriate intervals, placed them in moisture-tight containers, and transported
them to the laboratory for testing. We also utilized a standard penetration sampler (SPT)
alternately with the California sampler within the deep boring on the site to provide standard
penetration resistance values necessary for liquefaction analysis. SPT samples were placed in plastic
bags and transported to the laboratory. Disturbed bulk samples were also collected and transported
back to the laboratory for testing.
The sampler was driven up to 18 inches.The sampler is connected to A rods and driven into the bottom
of the boring using a 140-pound hammer. Blow counts are recorded for every 6 inches the sampler is
driven. The penetration resistances shown on the boring logs are shown in terms of blows per foot.
These values are not to be taken as N-values as adjustments have not been applied. We estimated
elevations shown on the boring logs either from a topographic map or by using a benchmark. Each
boring was backfilled with the cuttings generated during excavation.
The soil conditions encountered in the borings were visually examined,classified and logged in general
accordance with the Unified Soil Classification System(USCS). Logs of the bore holes are presented
on Figures A-1 through A-6. The logs depict the soil and geologic conditions encountered and the
depth at which samples were obtained. The approximate locations of the boreholes are indicated the
Geotechnical Map, Figure 2.
Geocon Project No.T2719-22-01 -A-1 - Junc 14,2016
PROJECT NO. T2719-22-01
w BORING B-1 Z W_ }
� pUF F wo_
DEPTH Q SOIL Z LL U LL H
IN SAMPLE
NO. p z CLASS ELEV.(MSL.) 1262 DATE COMPLETED 05/12/2016 D o a D H
FEET
� (USCS) w U)O - O Z
J � EQUIPMENT HOLLOW STEM AUGER BY:P.Therlault a co Of 0
0
MATERIAL DESCRIPTION
0
-1@0'-5 -I- SM ALLUVIUM(Qal)
Silty SAND,loose,slightly moist,blackish dark brown;fine to medium
sand;some coarse sand;micaceous;trace porosity;root hairs;some weeds
B-1@2.5' �"I" 15 101.1 7.0
4
-Becomes medium dense;trace light brown modling
B-1@5.0' 1 I" 35 122.4 9.3
6 T -1
g B-1@7.5' 1 -I -Becomes moist,strong brown;increase in coarse sand;trace fine gravel; 22
-1-i -II non-porous
J
10 -1@10.0 21
12 Y r
1@12.5 -{ "I -Becomes loose 6
14 -Becomes medium dense,brown;fine to coarse sand;trace clay
16 1@15.0 _ 26
18 -1@17.5 :{ I 10
20
1@20.0 I" 18 109.6 20.7
-Becomes loose,wet;increase in clay
22 I -Becomes grayish brown
1 @22.5 _ 7
24 1 � 1
-Becomes medium dense,saturated,brown;fine to coarse sand;some gravel
1@25.0 1 I 38 121.3 14.4
26 "I -Becomes medium dense
28 -1@27.5 t I" 22
1- -I-
I-
Figure A-1, T2719-22-01 BORING LOGS.GPJ
Log of Boring B-1, Page 1 of 2
SAMPLE SYMBOLS ❑ SAMPLING UNSUCCESSFUL ...STANDARD PENETRATION TEST ....DRIVE SAMPLE(UNDISTURBED)
®...DISTURBED OR BAG SAMPLE Q ...CHUNK SAMPLE 1 ...WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE
INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
GEOCON
PROJECT NO. T2719-22-01
w BORING B-1 Z W_ }
� pUF F wo_
DEPTH Q SOIL Z LL U LL H
IN SAMPLE
NO. p Z CLASS ELEV.(MSL.) 1262 DATE COMPLETED 05/12/2016 D o a D H
FEET
� (USCS) LLIZ U)O - O Z
J � EQUIPMENT HOLLOW STEM AUGER BY:P.Therlault a co Of 0
0
MATERIAL DESCRIPTION
30 -1@30.0 { -"I- -Becomes moist,brown;increase in clay 20
_{
32 { "I
-1@32.5 9
34 SM OLDER ALLUVIUM(Qoal)
Silty SAND,dense,moist,mottled orange and grayish brown;fine to
36
B-1@35' {-� medium sand;some coarse sand;micaceous;moderately cemented 62
38 -1@37.5 { 26
40 { I -Becomes dense,brown;trace clay;micaceous 39
42 -Becomes reddish brown;no clay
-1@42.5 { i 32
44
B-1@45' I I -Becomes wet 50-5"
46 { II"
48 -1@47.5 �-{ 62
{ t
50 { I -Becomes strong brown
B-1@50' --i - 50-3"
Total depth 51 feet,9 inches
Groundwater encountered at 36 feet, 11 inches.Stabilized at 26 feet,6 inches
No caving
Penetration resistance for 140 lb.hammer falling 30"by auto-hammer
Backfilled with cuttings on 5/12/2016
Figure A-1, T2719-22-01 BORING LOGS.GPJ
Log of Boring B-1, Page 2 of 2
SAMPLE SYMBOLS ❑ SAMPLING UNSUCCESSFUL ...STANDARD PENETRATION TEST ....DRIVE SAMPLE(UNDISTURBED)
®...DISTURBED OR BAG SAMPLE Q ...CHUNK SAMPLE 1 ...WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE
INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
GEOCON
PROJECT NO. T2719-22-01
w BORING B-2 Z W_ }
� pUF F wo_
DEPTH Q SOIL Z LL U LL H
IN SAMPLE
NO. p z CLASS ELEV.(MSL.) 1263 DATE COMPLETED 05/12/2016 D o a D H
FEET
� (USCS) w U)O - O Z
J � EQUIPMENT HOLLOW STEM AUGER BY:P.Therlault a co Of 0
0
MATERIAL DESCRIPTION
0 SM ALLUVIUM(Qal)
Silty SAND,medium dense,slightly moist,dark gray;fine to coarse sand;
2
micaceous;root hairs
{ "I-
B-2@2.5' 1 I- -Becomes moist 13 111.1 6.1
4
B-2@5' _-1 �-I- -Poorly developed carbonate stringers 41
g B-2@7.5' 1 -I -Becomes brown;decrease in coarse sand 18
1-� I
10 B 2@10' -I -Becomes reddish brown;no carbonates 22
12 t 1
14
B-2@15' _{ -I -Becomes brownish gray;trace gravel 30
16
Total depth 16.5 feet
No groundwater encountered
No caving
Penetration resistance for 140 lb.hammer falling 30"by auto-hammer
Backfilled with cuttings on 5/12/2016
Figure A-2, T2719-22-01 BORING LOGS.GPJ
Log of Boring B-2, Page 1 of 1
SAMPLE SYMBOLS ❑ SAMPLING UNSUCCESSFUL ...STANDARD PENETRATION TEST ....DRIVE SAMPLE(UNDISTURBED)
®...DISTURBED OR BAG SAMPLE Q ...CHUNK SAMPLE 1 ...WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE
INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
GEOCON
PROJECT NO. T2719-22-01
w BORING B-3 Z W_ }
� pUF F wo_
DEPTH Q SOIL Z LL U LL H
IN SAMPLE
NO. p z CLASS ELEV.(MSL.) 1270 DATE COMPLETED 05/12/2016 D o a D H
FEET
� (USCS) w U)O - O Z
J � EQUIPMENT HOLLOW STEM AUGER BY:P.Therlault a co Of 0
0
MATERIAL DESCRIPTION
0
B-3@0-5' �- -I- SM ALLUVIUM(Qal)
Silty SAND,medium dense,slightly moist,blackish dark brown;fine to
coarse sand;micaceous;some weeds
B-3@2.5' �"I- -Becomes brown;root hairs;trace gravel 20 118.2 4.7
4
B-3@5' _-1 I- -Becomes moist;trace carbonate stringers(poorly developed) 26 116.3 2.5
6 - -1
{ -Becomes reddish brown;carbonate stringers(poorly developed)
8 B-3@7.5' 1 -I 43 123.4 5.1
_
10 B-3@10' ""� 28
II -Gravel layer;no carbonates
12 I
3@12.5 { -I 36 112.1 5.3
14
B-3@15' { I 30
16
18 { �-
I--� I
20
B-3@20' { � 30
-Becomes wet;some clay
22 Y t
SM OLDER ALLUVIUM(Qoal)
24 Silty SAND,very dense,moist,mottled reddish brown and gray;fine to
coarse sand;micaceous;trace fine gravel
B-3@25' 90-11"
26
Total depth 26.5 feet
No groundwater encountered
No caving
Penetration resistance for 140 lb.hammer falling 30"by auto-hammer
Backfilled with cuttings on 5/12/2016
Figure A-3, T2719-22-01 BORING LOGS.GPJ
Log of Boring B-3, Page 1 of 1
SAMPLE SYMBOLS ❑ SAMPLING UNSUCCESSFUL ...STANDARD PENETRATION TEST ....DRIVE SAMPLE(UNDISTURBED)
®...DISTURBED OR BAG SAMPLE Q ...CHUNK SAMPLE 1 ...WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE
INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
GEOCON
PROJECT NO. T2719-22-01
W BORING B-4 Z LU }
} I_ OVF F LLIo
DEPTH O Q �
SAMPLE JO ?� SOIL Q Z LL 7 Z
IN NO 0 Z CLASS ELEV.(MSL.) 1268 DATE COMPLETED 05/12/2016LLI o a D F-
FEET =O (USCS) W W m Of 2 O
EQUIPMENT HOLLOW STEM AUGER BY:P.Therlault
MATERIAL DESCRIPTION
0 SM ALLUVIUM(Qal)
Silty SAND,medium dense,slightly moist,blackish dark brown;fine to
2 J
coarse sand;micaceous;some weeds
-Becomes brown;weak carbonate stringers;decrease in coarse sand 26
4 -�
B 4@5 1 I" 41
{ F" -Becomes moist,reddish brown;carbonate stringers
8 B-4@7.5' 1 -I" 31
10 B-4@10' �" 22
12
-Becomes strong brown;no carbonates
-4@12.5 - 20
14
B-4@15' { I -Increase in coarse sand;trace fine gravel(in shoe) 26
16
18 {
SM OLDER ALLUVIUM(Qoal)
20 B-4@20' 1 i -I Silty SAND,medium dense,moist,mottled reddish brown and brown;fine 40
to coarse sand;some gravel;micaceous
22
"I"- I
24 I
B-4@25' _i "I -No recovery 35
26 �- I
Total depth 26.5 feet
No groundwater encountered
No caving
Penetration resistance for 140 lb.hammer falling 30"by auto-hammer
Backfilled with cuttings on 5/12/2016
Figure A-4, T2719-22-01 BORING LOGS.GPJ
Log of Boring B-4, Page 1 of 1
SAMPLE SYMBOLS ❑ SAMPLING UNSUCCESSFUL ...STANDARD PENETRATION TEST ....DRIVE SAMPLE(UNDISTURBED)
®...DISTURBED OR BAG SAMPLE Q ...CHUNK SAMPLE 1 ...WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE
INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
GEOCON
PROJECT NO. T2719-22-01
w BORING B-5 Z W_ }
� pUF F wo_
DEPTH Q SOIL Z LL U LL H
IN SAMPLE
NO. p z CLASS ELEV.(MSL.) 1261 DATE COMPLETED 05/12/2016 D o a D H
FEET
� (USCS) w U)O - O Z
J � EQUIPMENT HOLLOW STEM AUGER BY:P.Therlault a co Of 0
0
MATERIAL DESCRIPTION
0 SM ARTIFICIAL FILL(afu)
Silty SAND,medium dense,slightly moist,brown;fine to medium sand;
chunks of AC
2 { II_I-
B-5@2.5' 1 I- 18
4
ML LACUSTRINE DEPOSITS(Ql)
Sandy SILT,firm,moist,olive;fine sand;micaceous
B-5@5' 8 94.1 23.8
6
g B-5@7.5' 24
-Trace weakly cemented carbonate
�- -I- SM ALLUVIUM(Qal)
10 II Silty SAND,loose,moist,brown with light brown mottling;fine to medium
B-5@10' -� I sand;some coarse sand;micaceous 11
12
-5@12.5 J_I � 15
-Trace poorly developed carbonate
14
B-5@15' �- � 22
16 - -Becomes olive;some clay
Total depth 16.5 feet
No groundwater encountered
No caving
Penetration resistance for 140 lb.hammer falling 30"by auto-hammer
Backfilled with cuttings on 5/12/2016
Figure A-5, T2719-22-01 BORING LOGS.GPJ
Log of Boring B-5, Page 1 of 1
SAMPLE SYMBOLS ❑ SAMPLING UNSUCCESSFUL ...STANDARD PENETRATION TEST ....DRIVE SAMPLE(UNDISTURBED)
®...DISTURBED OR BAG SAMPLE Q ...CHUNK SAMPLE 1 ...WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE
INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
GEOCON
PROJECT NO. T2719-22-01
w BORING B-6 Z W_ }
� pUF F wo_
DEPTH Q SOIL Z LL U LL H
IN SAMPLE
NO. p z CLASS ELEV.(MSL.) 1262 DATE COMPLETED 05/12/2016 D o a D H
FEET
� (USCS) w U)O - O Z
J � EQUIPMENT HOLLOW STEM AUGER BY:P.Therlault a co Of 0
0
MATERIAL DESCRIPTION
0
B-6@0-5' �" -"I- SM ARTIFICIAL FILL(afu)
Silty SAND,medium dense,moist,gray;fine sand;micaceous;some orange
staining;debris(AC chunks and rocks)
2 I -No debris
B-6@2.5' ""I" 16 96.8 6.6
4
B-6@5' I" 13 97.6 15.8
6 i
ML LACUSTRINE DEPOSITS(Ql)
8 B-6@7.5' Sandy SILT,stiff,moist,grayish brown;fine sand;micaceous 14
10 B-6@10' 17
-Becomes brown;some clay
12 SM ALLUVIUM(Qal)
6@12.5 "-1 i -I Silty SAND,medium dense,moist,reddish brown;fine sand 17 112.0 18.2
14 { �F"
- 1 -
B-6@15' _1 i"I 15
16 -� -Becomes fine to coarse sand
18
20 B-6@20' J "II 15
1-� I
22
24
SC Clayey SAND,stiff,moist,grayish brown;fine to coarse sand;trace fine
B-6@25' / gravel;micaceous 23
26
Total depth 26.5 feet
No groundwater encountered
No caving
Penetration resistance for 140 lb.hammer falling 30"by auto-hammer
Backfilled with cuttings on 5/12/2016
Figure A-6, T2719-22-01 BORING LOGS.GPJ
Log of Boring B-6, Page 1 of 1
SAMPLE SYMBOLS ❑ SAMPLING UNSUCCESSFUL ...STANDARD PENETRATION TEST ....DRIVE SAMPLE(UNDISTURBED)
®...DISTURBED OR BAG SAMPLE Q ...CHUNK SAMPLE 1 ...WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE
INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
GEOCON
APPENDIX 4 0
APPENDIX B
LABORATORY TESTING
Laboratory tests were performed in accordance with generally accepted test methods of the"American
Society for Testing and Materials (ASTM)", or other suggested procedures. Selected samples were
tested for direct shear strength, consolidation, expansion characteristics, corrosivity, atterberg limits,
grain size analysis, and in-place dry density and moisture content. The results of the laboratory tests
are summarized in Figures B-1 through B-9. The in-place dry density and moisture content of the
samples tested are presented on the boring logs,Appendix A.
Geocon Project No.T2719-22-01 -B-1 - June 14,2016
7.0
DRY INITIAL FINAL
SAMPLE SOIL TYPE DENSITY MOISTURE(%) MOISTURE(%)
B2@2'/2 SM 111.1 6.1 14.8
B4 @ 2'/2 SM 96.8 6.6 24.6
6.0
LL 5.0
Co
IZ-
+� 4.0
v� B2 @ 2Y2'
^C:
B4
4-j
U) 3.0
W B2 @ 2'/2
IZ-
2.0 '/z B4 @ 2
�30 S
O
1.0 B2 @ 2'/2
B4@2'/2
0
0 1.0 2.0 3.0 4.0 5.0 6.0
Normal Pressure (KSF)
• Direct Shear, Saturated
GE O,C,ONOw
DIRECT SHEAR TEST RESULTS
w E S T, I N C. LAKE RESORT APARTMENTS
ENVIRONMENTAL GEOTECHNICAL MATERIALS E. OF GRAND AVE.AT VAIL ST.
41571 CORNING PLACE,SUITE 101,MURRIETA,CA 92562 LAKE ELSINORE, CALIFORNIA
PHONE (951)304-2300 - FAX (951)304-2392
Drafted by: RDG Checked by: HHD JUNE,2016 7 PROJECT NO.T2719-22-01 FIG. B1
7.0
DRY INITIAL FINAL
SAMPLE SOIL TYPE DENSITY MOISTURE(%) MOISTURE(%)
B3 @ 0-5' SM 114.5 9.3 15.4
B6 @ 0-5' SM 96.8 6.6 24.6
6.0
LL 5.0
Co
IZ-
4.0
B3 @ 0-5' 40
^C:
B6 @ 0-5'
4-j
3.0
W B3 @ 0-5'
IZ—
/� B6 @ 0-5' 11-1
v� 2.0
S
G.�30
Q
1.0 B3 0-5'
B6 @ 0-5'
0
0 1.0 2.0 3.0 4.0 5.0 6.0
Normal Pressure (KSF)
• Direct Shear, Saturated
GE O,C,ONOw
DIRECT SHEAR TEST RESULTS
w E S T, I N C. LAKE RESORT APARTMENTS
ENVIRONMENTAL GEOTECHNICAL MATERIALS E. OF GRAND AVE.AT VAIL ST.
3303 N.SAN FERNANDO BLVD.-SUITE 100-BURBANK,CA 91504 LAKE ELSINORE, CALIFORNIA
PHONE (818)841-8388 - FAX (818)841-1704
Drafted by: RDG Checked by: HHD JUNE,2016 7 PROJECT NO.T2719-22-01 FIG. 132
WATER ADDED AT 2 KSF
0 B 1 @2' '
2
4
6
.O 8
0 B2@2' '
O
O 2
U
4
cj
U
8
0 B5@2' '
2
4
6
8
.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 2 3 4 5 6 7 8 9 10
Consolidation Pressure (KSF)
GE O,C,ON QW)
CONSOLIDATION TEST RESULTS
W E S T, I N C. LAKE RESORT APARTMENTS
ENVIRONMENTAL GEOTECHNICAL MATERIALS E. OF GRAND AVE.AT VAIL ST.
41571 CORNING PLACE,SUITE 101,MURRIETA,CA 92562 LAKE ELSINORE, CALIFORNIA
PHONE (951)304-2300 - FAX (951)304-2392
Drafted by: RDG Checked by: HHD JUNE, 2016 7 PROJECT NO.T2719-22-01 FIG. B3
WATER ADDED AT 2 KSF
0 B3@7' '
2
4
6
.O 8
7�
0 B5@7' '
O
O 2
U
4
cj
U
8
B3@12/2
0
2
4
6 17
8
.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 2 3 4 5 6 7 8 9 10
Consolidation Pressure (KSF)
GE O,C,ON QW)
CONSOLIDATION TEST RESULTS
W E S T, I N C. LAKE RESORT APARTMENTS
ENVIRONMENTAL GEOTECHNICAL MATERIALS E. OF GRAND AVE.AT VAIL ST.
41571 CORNING PLACE,SUITE 101,MURRIETA,CA 92562 LAKE ELSINORE, CALIFORNIA
PHONE (951)304-2300 - FAX (951)304-2392
Drafted by: RDG Checked by: HHD JUNE, 2016 7 PROJECT NO.T2719-22-01 FIG. B4
WATER ADDED AT 2 KSF
0 B6@12/2
2
4
6
.O 8
7�
0 B1@20
O
O 2
U
4
6
8
0 B 1 @25
2
4
6
8
.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 2 3 4 5 6 7 8 9 10
Consolidation Pressure (KSF)
GE O,C,ON QW)
CONSOLIDATION TEST RESULTS
W E S T, I N C. LAKE RESORT APARTMENTS
ENVIRONMENTAL GEOTECHNICAL MATERIALS E. OF GRAND AVE.AT VAIL ST.
41571 CORNING PLACE,SUITE 101,MURRIETA,CA 92562 LAKE ELSINORE, CALIFORNIA
PHONE (951)304-2300 - FAX (951)304-2392
Drafted by: RDG Checked by: HHD JUNE, 2016 7 PROJECT NO.T2719-22-01 FIG. B5
80
70
60
X
uJ 50
0 Z
40 CH
U 30
CL OH a d MH
Q 20
/0000,
J CL- L
10
0 M and L
0 10 20 30 40 50 60 70 80 90 100 110
LIQUID LIMIT, LL
BORING DEPTH MOISTURE
NUMBER (FEET) LL PL PI SAONTENT N T SOIL BEHAVIOR
B1 12'/z --- --- --- --- N/P
B1 17'/2 --- --- --- --- N/P
B1 27'/2 --- --- --- --- N/P
B1 30 --- --- --- --- N/P
B1 32'/2 --- --- --- --- N/P
B1 37'/2 --- --- --- --- N/P
B1 40 --- --- --- --- N/P
*N/P indicates Non-Plastic
GEOCON <0)
ATTERBERG LIMITS
w E S T, I N C. LAKE RESORT APARTMENTS
ENVIRONMENTAL GEOTECHNICAL MATERIALS E. OF GRAND AVE.AT VAIL ST.
41571 CORNING PLACE,SUITE 101,MURRIETA,CA 92562 LAKE ELSINORE, CALIFORNIA
PHONE (951)304-2300 - FAX (951)304-2392
Drafted by: RDG Checked by: HHD JUNE, 2016 PROJECT NO. T2719-22-01 FIG. B6
GRAVEL SAND SILT CLAY
MEDIUM TO COARSE FINE
W
U.S. Standard Sieve Sizes
'O7-' Z Z Z Z Z
O 100
O
N
O80
60
�j 1 @ 17'/2
rl--I-i
40 2
1 Cc 37'/i
1 Cc 12'/z
a 20 1 27 i
w 0
O
W GRAIN DIAMETER (mm)
a�
SAMPLE PERCENT PASSING NO. 200 SIEVE
B1 @ 12'/2' 35.5
B 1 @ 17Y2' 42.0
B 1 @ 27'/s' 35.1
B1 @ 32'/2 39.4
B 1 @ 37'/a' 37.7
B1 @ 40' 39.8
GEOCONQW)
GRAIN SIZE ANALYSIS
W E S T, I N C.
LAKE RESORT APARTMENTS
ENVIRONMENTAL GEOTECHNICAL MATERIALS E. OF GRAND AVE.AT VAIL ST.
41571 CORNING PLACE,SUITE 101,MURRIETA,CA 92562 LAKE ELSINORE, CALIFORNIA
PHONE (951)304-2300 - FAX (951)304-2392
Drafted by: RDG Checked by: HHD JUNE, 2016 PROJECT NO. T2719-22-01 FIG. B7
SUMMARY OF LABORATORY EXPANSION INDEX TEST RESULTS
ASTM D 4829-11
Moisture Content % Dry Expansion *UBC **CBC
Sample No. Before After Density(pcf) Index Classification Classification
B3 @ 0-5' 8.4 13.3 115.8 3 Very Low Non-Expansive
B6 @ 0-5' 10.8 20.8 104.7 3 Very Low Non-Expansive
Reference: 1997 Uniform Building Code, Table 18-1-B.
Reference: 2013 California Building Code, Section 1803.5.3
SUMMARY OF LABORATORY MAXIMUM DENSITY AND
AND OPTIMUM MOISTURE CONTENT TEST RESULTS
ASTM D 1557-12
Soil Maximum Dry Optimum
Sample No. Description Density cf Moisture
B3 @ 0-5' Dark Brown Silty Sand 131.0 7.5
B6 @ 0-5' Dark Olive Gray Silty Sand 120.0 11.0
GE O,C ON ���� LABORATORY TEST RESULTS
w E S T, I N C. LAKE RESORT APARTMENTS
ENVIRONMENTAL GEOTECHNICAL MATERIALS E. OF GRAND AVE.AT VAIL ST.
41571 CORNING PLACE,SUITE 101,MURRIETA,CA 92562 LAKE ELSINORE, CALIFORNIA
PHONE (951)304-2300 - FAX (951)304-2392
Drafted by: RDG Checked by: HHD JUNE, 2016 PROJECT NO.T2719-22-01 FIG. B8
SUMMARY OF LABORATORY POTENTIAL OF
HYDROGEN (pH) AND RESISTIVITY TEST RESULTS
CALIFORNIA TEST NO. 643
Sample No. pH Resistivity (Ohm Centimeters)
133 @ 0-5' 7.5 7002 (Moderately Corrosive)
SUMMARY OF LABORATORY CHLORIDE CONTENT TEST RESULTS
EPA NO. 325.3
Sample No. Chloride Ion Content (%)
B3 @ 0-5' 0.004
SUMMARY OF LABORATORY WATER SOLUBLE SULFATE TEST RESULTS
CALIFORNIA TEST NO. 417
Sample No. Water Soluble Sulfate (% SO4) Sulfate Exposure*
B3 @ 0-5' 0.001 Negligible
*Reference: 2013 California Building Code, Section 1904.3 and ACI 318-11 Section 4.3.
GE O,C,ONOw
CORROSIVITY TEST RESULTS
W E S T, I N C. LAKE RESORT APARTMENTS
ENVIRONMENTAL GEOTECHNICAL MATERIALS E. OF GRAND AVE.AT VAIL ST.
41571 CORNING PLACE,SUITE 101,MURRIETA,CA 92562 LAKE ELSINORE, CALIFORNIA
PHONE (951)304-2300 - FAX (951)304-2392
Drafted by: RDG Checked by: HHD JUNE,2016 7 PROJECT NO.T2719-22-01 FIG. B9
APPENDIX
TERRA
GEOSCIENCES
EVALUATION OF SURFACE FAULT RUPTURE HAZARD
ELSINORE VIEW MOBILE HOME PARK PROJECT
ASSESSOR'S PARCEL NOS. 371-150-001 & -002 (4.51AC & 2.25AC)
AND 371-090-001 & -002 (4.55AC & 2.27AC)
CITY OF LAKE ELSINORE, RIVERSIDE COUNTY, CALIFORNIA
Project No. 152772-1
March 31, 2015
Prepared for:
Matrix Geotechnical Consulting
P.O. Box 2161
Temecula, California 92593
Consulting Engineering Geology&Geophysics
P.O. Box 1090, Loma Linda, CA 92354 • 909 796-4667
Matrix Geotechnical Consulting March 31, 2015
P.O. Box 2161 Project No. 152772-1
Temecula, CA 92593
Attention: Mr. Chris Josef
Regarding: Evaluation of Surface Fault Rupture Hazard
Elsinore View Mobile Home Park Project
Assessor's Parcel Nos. 371-150-001 & -002 (4.51ac & 2.25ac)
and 371-090-001 & -002 (4.55ac & 2.27ac)
City of Lake Elsinore, Riverside County, California
EXECUTIVE SUMMARY
At your request, we have completed an evaluation of the potential for surface fault-
rupture hazard within the proposed 13.58±-acre mobile home park as referenced above.
In summary, it was found that there is an active fault zone that traverses through the
central portion of the subject property, which required establishment of a "Restricted-
Use Zone" for "habitable" building purposes. Additionally another "Restricted-Use Zone"
was also established along the northernmost portion of the site where subsurface
exploration was not performed to evaluate faulting potentials within the designated
County fault Zone. These Restricted-Use Zones are presented on a topographic base
map that was provided by VSL Surveying, Temecula, California, which displays the
surveyed fault locations and exploratory trenches along with other pertinent geologic
data for documentation purposes.
This opportunity to be of service is sincerely appreciated. If you should have any
questions regarding this report or do not understand the limitations of this study or the
data that is presented, please contact our office.
Respectfully submitted, �SS�ONAL Q
TERRA GEOSCIENCES of C-SCHWARr2� O�
w y
CERTIFIED �
i�J�f x�� 1 ENGINEERING
^ GEOLOGIST
Donn C. Schwartzkopf �� No.1459 �Q
Professional Geologist, PG 4094 OF CALIF���
Certified Engineering Geologist, CEG 1459
TERRA GEOSCIENCES
TABLE OF CONTENTS
Page No.
INTRODUCTION 1
SCOPE OF SERVICES 1
GEOLOGIC SETTING 2
LOCAL FAULTING 4
PHOTOGEOLOGIC SUMMARY 5
FIELD RECONNAISSANCE 6
SUBSURFACE EXPLORATION 6
Exploratory Trench T-1 7
Exploratory Trenches T-2 though T-4 9
Exploratory Trench Summary 9
RELATIVE AGE DATING 10
CONCLUSIONS & RECOMMENDATIONS 10
General 10
Conclusions 11
Recommendations 13
1. Restricted-Use Zones 13
2. Additional Work 14
3. Trench Backfill 14
CLOSURE 14
ILLUSTRATIONS
Geomorphic Map Figure 1
Regional Geologic Map Figure 2
County Fault Zone Map Figure 3
Topographic Map Figure 4
Comparison Geologic Map Figure 5
Geologic Site Map Plate 1
APPENDICES
Exploratory Trench Logs Appendix A
Site Photographs Appendix B
References Appendix C
TERRA GEOSCIENCES
Project No. 152772-1 Page 1
INTRODUCTION
At your request, this firm has performed an evaluation of the potential for surface fault
rupture with respect to the proposed 13.58± acre site. We understand that the site is
proposed for development of a mobile home park and associated appurtenances, which
includes undetermined amounts of cut and fill grading. No grading plans were available
at the time this report was prepared. The subject property lies along the southeastern
edge of Lake Elsinore, in the City of Lake Elsinore, Riverside County, California, and
geographically lies within the southern half of Section 16, Township 6 South, Range 4
West, SBB&M. and shown on Figure 4. For visual and reference purposes, overall
photographic views of the exploratory trenches are presented within Appendix B.
The project lies approximately 2,000± feet to the southwest of an established
Earthquake Fault Zone that is associated with the Elsinore Fault Zone (Wildomar Fault),
as mapped by the California Geological Survey (Bryant and Hart, 2007). However, the
site is shown to be located within a designated County Fault Zone as indicated on
Figure 3. This report has been prepared utilizing the suggested "Guidelines for Evaluat-
ing the Hazard Surface Fault Rupture" (California Division of Mines and Geology, Note
49) in addition to the County of Riverside "Technical Guidelines for Review of
Geotechnical and Geologic Reports" (2000). We understand that groundwater, seismic,
and other associated pertinent geologic data will be discussed within your geotechnical
report, of which this report will be an appendix.
SCOPE OF SERVICES
As authorized by you, the following services were performed during this study:
y Review of available published and unpublished geologic/geophysical data in our files
pertinent to the site.
Photogeologic analysis of stereoscopic pairs of aerial photographs that were obtained
from the Riverside County Flood Control District and other sources.
➢ Geologic field reconnaissance of the site by a State of California licensed Certified
Engineering Geologist.
Subsurface investigation by means of stratigraphic logging of 1,901 lineal feet of
exploratory trench, up to 14± feet in depth.
➢ Field accompaniment with the project land surveyor (VSL Survey) delineating the
necessary survey locations which included the exploratory trench limits and fault
locations.
➢ Field meeting with the Riverside County Geologist (Mr. David Jones) for the purpose of
viewing the exploratory trenching and discussing our findings.
➢ Preparation of this report, which presents the results of our findings, conclusions, and
recommendations relating to the potential for surface fault rupture at the site, with
respect to the proposed development.
TERRA GEOSCIENCES
Project No. 152772-1 Page 2
GEOLOGIC SETTING
The subject site is situated within a natural geomorphic province in southwestern
California known as the Peninsular Ranges, which is characterized by steep, elongated
ranges and valleys that trend northwesterly. This province is believed to have begun as
a thick accumulation of predominantly marine sedimentary and volcanic rocks during
the late Paleozoic and early Mesozoic (pre-batholithic rocks). Following this
accumulation, in mid-Cretaceous time, the province underwent a pronounced episode of
mountain building. The accumulated rocks were then complexly metamorphosed and
intruded by igneous rocks, known locally as the Peninsular Ranges Batholith. A period
of erosion followed the mountain building, and during the late Cretaceous and Cenozoic
time, sedimentary and subordinate volcanic rocks were deposited upon the eroded
surfaces of the batholithic and pre-batholithic rocks (post-batholithic rocks). Most of
these post-batholithic rocks occur along the western and northern potion of the
province.
More specifically, the site lies along the boundary of two sub-structural blocks of the
Peninsular Range province, with the Perris Block to the northeast and the Santa Ana
Mountain Block to the southwest (see Figure 1 below). These two structural blocks are
separated by the Elsinore Fault Zone, of which is one of the major structural features of
southern California and can be traced from the Puente Hills to the north to the Mexican
Border along the south, a distance of 200± kilometers (Hull and Nicholson, 1992).
1.
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FIGURE 1- Geomorphic map of a portion of the north-central Peninsular Ranges (modified from Morton and
Weber, 2003). Red band shows age contour offsets (right lateral)across Elsinore Fault Zone.
TERRA GEOSCIENCES
Project No. 152772-1 Page 3
Along its length, the Elsinore Fault Zone forms numerous complex series of pull-apart
basins, with the most distinct closed basin forming La Laguna, which is partly filled by
Lake Elsinore, of which the site is partially located near its southeastern margin. Locally
this basin, which is bounded by active faults, is essentially a graben, where a block or
portion of the earth's crust has been down-dropped along faults relative to the
surrounding areas that have been uplifted.
Locally, as mapped by Morton and Weber (2003), indicated on Figure 2 below, the
central elevated hillier portion of the site is shown to consist of Pleistocene sedimentary
bedrock locally referred to as the Pauba Formation, which is generally described as a
moderately well-indurated channeled and filled siltstone, sandstone, and conglomerate
facies. Locally, the Pauba Formation has been further subdivided into a sandstone
member (Qpfs) that is generally comprised of moderately well-indurated, cross-bedded
sandstone, containing sparse cobble- to boulder-conglomerate beds. Northeast of this
hill, the site is shown to be mantled by late Holocene age lacustrine deposits (QI),
generally described as clayey, silty and fine-grained sediments. The surficial sediments
southwest of the hill have been mapped as Holocene and late Pleistocene fluvial
deposits derived as alluvial valley outwash (Qyv), consisting of unconsolidated sand,
silt, and clay. This more recent published mapping generally coincides with previous
mapping prepared by Webber (1977).
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FIGURE 2- Partial geologic map of the Elsinore 7.5' Quadrangle (Morton and Weber, 2003). Symbol "QI"
represents lacustrine deposits (late Holocene), "Qyv" indicates alluvial-valley deposits (Holocene
and late Pleistocene), with "Qpfs" denoting bedrock of the Pauba Formation (Pleistocene).
Dashed/dotted lines depict faults while thin solid lines depict geologic contacts. The property
boundary is outlined in red.
TERRA GEOSCIENCES
Project No. 152772-1 Page 4
Based on our subsurface exploration and as discussed further in this report, these
geologic units are generally consistent with our findings. However, the actual mapped
earth materials and fault locations shown on Figure 2 vary somewhat across the site.
LOCAL FAULTING
According to the State of California (C.D.M.G., 1980), the site is shown to be located
just to the west of a designated Alquist-Priolo Earthquake Fault Zone (see Figure 3
below). This fault is locally referred to as the Wildomar Fault, which is one of the central
strands of the Elsinore Fault Zone System (part of the Temecula Segment), which runs
from the Los Angeles Basin to the north, into Mexico to the south. The Wildomar Fault
is a right-lateral, strike-slip fault, being approximately 42 kilometers in length. Weber
(1977), the County of Riverside (2000), and Morton and Weber (2003), indicate two
discontinuous unnamed fault branches to traverse through the site as shown Figure 2
and on Figure 3 below. The red-shaded fault zone as indicated on Figure 3 below was
the basis for this surface fault hazard report.
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FIGURE 3- Partial map the County Fault Zone Map (County of Riverside, 2000). Faults are indicated by solid
red lines with the fault zones defined by the red shading. The northeast-southwest trending
blue line is the approximate trench location. The purple shaded zone east of the site is the
Wildomar Fault as zoned by the C.D.M.G. (1980). Site is outlined in black.
TERRA GEOSCIENCES
Project No. 152772-1 Page 5
PHOTOGEOLOGIC SUMMARY
A detailed review of pertinent stereoscopic aerial photographs was performed for this
study for the purposes of evaluating the geomorphology of the site, specifically for the
presence of photogeologic features (e.g. linear topography, tonal contrasts, etc.) that
may traverse through the subject property. Eight sets of photographs at various scales
were reviewed between the years 1938 to 2010 (see references in Appendix C for a
listing), that were obtained from the Riverside County Flood Control Department and
U.S. Department of Agriculture. In addition, the historical imagery database of Google
Earth (GoogleTm Earth, 2013) was also utilized.
Review of these photographs revealed two linear geomorphic features that traverse
through the subject property and are depicted on the accompanying topographic map,
as shown on Figure 4 below. The two lineaments traverse along a northwest-southeast
direction along the northern and southern base of the hill within the central potion of the
site. This feature is expressed as linear topography that forms a fairly sharp
geomorphic boundary delineated by a scarp on the south side of the hill, with a subdued
expression on the north, due to lake sediment deposition. Numerous water level stands
were observed parallel with the fault zone trend in the north which masked any possible
lineations that could be present north of the central hill. Other than the two delineated
lineaments as presented on Figure 4 below, no photogeologic features unrelated to
flooding and/or historic lake levels were observed to traverse through the site, based on
the aerial photographs reviewed.
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FIGURE 4- Partial topographic map the Lake Elsinore 7.5' Quadrangle (U.S.G.S., 1997). Photo lineaments
are shown as the purple dotted lines. Site boundary is outlined in red.
TERRA GEOSCIENCES
Project No. 152772-1 Page 6
Of importance to note is the presence of water that is delineated on the topographic
map that surrounds the central hillier portion of the site. This high water elevation was
evident in the 1938 and 1980 photographs reviewed, with the water having a "lagoon-
like" appearance south of the hill. Lake Elsinore is supplied by inflow from the San
Jacinto River and local watershed runoff which eventually can increase the water
elevation in the lake until the outflow channel elevation of 1255 feet is reached, thus
resulting in discharge of lake flows to Temescal Creek. During significant storm events,
if the inflow to Lake Elsinore is greater than the outlet channel capacity, the surface
water elevation of the lake will continue to rise until it reaches 1262 feet, resulting in the
potential to reach the lake levee top elevation of 1265 feet (E.V.M.W.D., 2015). During
our investigation, the water level elevation was around 1238± feet.
FIELD RECONNAISSANCE
Surficial reconnaissance performed during our field investigation revealed a prominent
topographically higher hill within the central portion of the site. Based on the known
local faulting, this hill is suspected of being a localized pressure ridge, such as Rome
Hill, located just to the southeast. Pressure ridges can form where lateral motions on a
typically curving fault will force rocks into a smaller space, resulting in pushing them
upward, of which has formed the small hill situated within the central portion of the site.
These ridges, or hills, are then bounded on both sides by a fault. The remainder
northern and southern portions of the site are relatively flat-lying and are covered by a
growth of annual weeds and grasses. These areas did not provide any geomorphic or
visual indications suggestive of fault-related features.
SUBSURFACE EXPLORATION
One 1,716-foot long exploratory trench (T-1) was excavated ranging in depth from 8± to
14± feet. This trench was excavated in a general northeast to southwest direction,
being near normal to the general trend of the Elsinore Fault Zone. It should be noted
that the total length of this trench as indicated on the log presented within Appendix A is
shown to be 1,736 feet in length. This is due to a sewer easement that traverses
through the site where a 20-foot wide zone was left undisturbed that could not be
trenched across. Based on the initial findings in this trench, three small check trenches
were also excavated west of and parallel to Exploratory Trench T-1, with these being
60, 50, and 75 feet in length (Exploratory Trenches T-2, T-3, and T-4, respectively).
The surveyed locations of all the exploratory trenches are presented on the Geologic
Site Map, included as Plate 1. Graphic logs of the exploratory trenches (7 sheets) are
provided within Appendix A, which were prepared at a scale of one inch equals eight
feet (horizontal and vertical) and depict the structure and Iithologic nature of the earth
materials encountered locally. This scale was deemed appropriate for this project due
to the generally uniform and continuous Iithologic features exposed along the trench
walls. The southeastern trench side-wall was continuously logged for this study.
TERRA GEOSCIENCES
Project No. 152772-1 Page 7
In general, the earth materials that were encountered within these trenches consisted of
Holocene to late Pleistocene age Iacustrine and fluvial deposits, and Pleistocene age
sedimentary bedrock of the Pauba Formation, and are described in more detail below.
In addition, localized historical deposits of artificial fill mantle a large portion of the site
on both sides of the hill. These materials were placed sometime between the years
1980 and 1990 based on our photogeologic review. It is believed that these materials
were placed in an attempt to elevate the land surface to above historic flood level limits
locally, to prevent any local future flooding. These deposits appear on the trench log
but have been omitted from the Geologic Site Map (see Plate 1) in order to better
illustrate the natural geologic units that comprise the site.
A description of each earth material unit encountered is provided in Appendix A (see
Lithologic Descriptions, Page A-2) that describe their main physical characteristics (i.e.
color, grain size, soil structure, density/induration, etc.). These Iithologic descriptions
should be referred to when reading the trench summaries given below. Also included
within Appendix A is a legend, which groups the earth materials together based on their
depositional origins and estimated ages, and a key to the symbols used on the trench
logs (see Legend, Page A-1).
Exploratory Trench T-1
This exploratory trench was excavated within an area that is encompassed by the
designated County Fault Zone, as shown on Figure 3, along a near-perpendicular
direction to the fault zone trend. This trench extended just beyond the southern fault
zone limit, with the end of the trench in the north extending approximately 75 feet north
of the proposed development limits as delineated by the client. Although the trench was
not extended across the zone boundary in the north, sufficient coverage was maintained
with respect to the project development limits.
Initially encountered at the beginning of the exploratory trench in the north, are
Iacustrine sediments (QI) that have originated as lake deposits from Lake Elsinore.
These deposits extend from Station 0+00 to Station 4+37 and consist of Units "A"
through "G." The surface is mantled by an unconsolidated sand unit that averages just
one-foot in thickness (Unit "A") being very recent (modern deposits). Directly below this
layer are progressively older (late- to mid-Holocene) moderately indurated to very
firm/indurated sediments, herein in termed Units "B", "D", and "C." None of these
Iacustrine units displayed visible signs of fracturing, faulting, or deformation.
Around Stations 2+75 to 3+15, these deposits are in turn underlain by well-indurated
late Pleistocene age Iacustrine deposits separated by an unconformable erosional
contact. These deposits (Units "E", "F", and "G") are distinctly well-stratified and tilted at
an angle of between 20 to 25 degrees to the northeast. It is believed that this tilting is a
direct result of tectonic uplift and deformation from local faulting, likely associated with
the northernmost fault encountered in this trench, at Station 4+37. At this location, the
Iacustrine deposits are juxtaposed against Pleistocene age sedimentary bedrock of the
Pauba Formation (Qpfs), which forms the north boundary of the fault zone.
TERRA GEOSCIENCES
Project No. 152772-1 Page 8
This fault locally has a relatively low-angle dip towards the northeast, trending in an
overall N50W direction (when connected to T-4). Due to previous grading that had
occurred to place the overlying artificial fill materials across the fault, potential Holocene
disruption or offsets could not be observed or verified. Although not mapped as a
geologic unit on the Geologic Site Map (Plate 1), the artificial fill materials (af) become
visible beginning around Station 4+00 and extend to Station 11+85, generally near the
terminus of the lacustrine deposits along the south. The thickness of this unit varies
locally up to 5± feet deep and it contains an abundance of asphalt chunks, numerous
large boulders (up to 5± feet in diameter), miscellaneous debris, and assorted trash,
with a fine- to coarse grained silty sand matrix in a loose condition.
Between Stations 4+37 to 5+55, the Pauba Formation, which consists of interbedded
sandstone and silty sandstone (Units "R" through "U"), is somewhat disturbed and
fractured, containing numerous faults that offset different sedimentary beds. At Station
5+55, a significant fault was encountered which completely separates the local bedrock
structure and lithology. Additionally, within Unit "V," direct evidence was observed that
this fault displaces recent age channel sands (very late Holocene) by up to 10± vertical
inches, with thin radial fractures extending into the sands overlying the visible upward
terminus of the fault. South of this fault zone extending to Station 7+57, the Pauba
Formation consists predominantly of a highly fractured and faulted massive silty
sandstone overlain by an argillic clayey silty sandstone (Units "W" and "X" respectively).
Another significant fault was observed at Station 7+29, where again major sedimentary
bedrock units are juxtaposed. These materials (Unit "Y") consist of a well-stratified silty
sandstone with numerous thin sand lenses dipping a various low angles.
At Station 7+57 a major fault was encountered that separates the Pauba formation on
the north, with fluvial and lacustrine deposits to the south. This fault forms the southern
margin of the central hill and is coincident with the aerial photo lineation as shown on
Figure 4. This fault is accompanied by a highly sheared zone (Unit "Z") that is
variegated and intensely fractured/faulted. This fault also offsets recent age lacustrine
sediments (late Holocene) which are comprised of unconsolidated, loose, well-stratified
sands (Unit "M"). Locally where exposed, there may be as much as 30± inches of
apparent vertical offset between the Pauba Formation and these sediments.
Beyond Station 7+57 the site is mantled (directly beneath the overlying fill) by lacustrine
sediments (Units "H" through "M") that were deposited during periods of very high lake
water elevations that forms the intermittent "lagoon" on the south side of the central hill,
which are in turn underlain by fluvial deposits at depth. These relatively shallow lake
deposits extend southward to Station 11+94, generally where the overlying artificial fill
materials end. As discussed earlier, it would appear that this coincides to the original
topographically lower elevation of the site, which would correlate to the limits of the
historic high-water lake edge as marked by the southern limits of the lake deposits.
Based on the firmness, presence of disseminated CaCO3 and nodules, and localized
clay films along the ped faces, these deposits (with the exception of Unit "M") appear to
be at least middle Holocene to possible late Pleistocene in age.
TERRA GEOSCIENCES
Project No. 152772-1 Page 9
The fluvial sequence of earth materials along the south side of the hill are first exposed
at Station 7+57, juxtaposed against the Pauba Formation. Here Unit "N" was observed
to be entrenched by the overlying lacustrine deposits and extends to Station 8+14
where they have been eroded to a depth below the bottom of the trench. The fluvial
deposits then reappear around Station 10+05 at depth below the lacustrine deposits.
For reference, the boundary between the fluvial and lacustrine deposits has been
denoted as a "facies contact" as depicted on the Exploratory Trench Log (Sheets 3 and
4, Pages A-5 & A-6). Around Station 11+32, the earth materials mantling the site are
fluvial deposits (Unit "Q") which are relatively young unconsolidated silty sands (late
Holocene). By Station 11+94, only fluvial deposits were observed to the end of the
trench at Station 17+36. The fluvial units underlying the youthful Unit "Q" have been
estimated to have an age ranging from middle Holocene to late Pleistocene based on
relative induration, great abundance of CaCO3 in the form of blebs and stringers, and
the grussification of the occasional felsic gravel-sized clasts observed. These deposits
(Units "N through "P") did not show direct evidence of soil cracking, fracturing, or other
deformation, that could be related to faulting.
It should again be mentioned that due to the presence of a high-pressure sewer line
(located in the field by a representative of the Elsinore Valley Municipal Water District),
the exploratory trench between Stations 14+80 to 15+00 could not be excavated.
However, the sequence of the underlying fluvial deposits was noted to be consistent
across the untrenched gap and the Iithologic contacts appear to be continuous at depth
through this area (see Exploratory Trench Log T-1, Sheet 5 of 6). The exploratory
trench was then terminated at Station 17+36, which is located just beyond the limit of
the designated County Fault Zone, as depicted on Figure 3.
Exploratory Trenches T-2 through T-4
Three short check trenches were excavated to the west of Exploratory Trench T-1 for
the purposes of locating the three main fault splays that were initially encountered and
determining their trend across the property. These trenches all had similar lithology that
matches the Iithology exposed in Exploratory Trench T-1. Each major fault was clearly
identified that provided a means to trace the local fault trend across the property.
Exploratory Trench T-2 and T-3 displayed somewhat subdued faulting structures
directly as a result of previous earthwork and/or shoreline erosion.
Exploratory Trench T-4, however, provided an exceptional exposure of the southern
fault zone splay. Here the fault (consisting of a zone of closely spaced faults) displays
very recent activity noted by the overlying offset sand channel (Unit "M"), which has an
apparent cumulative vertical offset of up to 30± inches and closely resembles the
faulting observed in Exploratory Trench T-1. Numerous radial fractures clearly extend
into the overlying sand channel deposits. It is believed that this sand channel could
have an age estimated to be less than 1,000 years based on the friable and loose
nature of the sediments. The fault zone that was encountered in Exploratory Trench T-
4 was also logged in greater detail (1 inch = 2 feet) for illustrative purposes, and
appears on Exploratory Trench Log T-4 found within Appendix A (see Page A-9).
TERRA GEOSCIENCES
Project No. 152772-1 Page 10
Exploratory Trenching Summary
The central, hillier portion of the site (between Stations 4+37 to Station 7+57), was
found to consist of well-indurated sedimentary bedrock of the Pauba Formation that is
highly faulted, sheared, and fractured, which is contained within the fault zone that
traverses through the site. Outside of this designated fault zone (areas comprising
Stations 0+00 to 4+37 and Stations 7+57 to 17+36), it was found that there were
continuous and unbroken lithologic lacustrine and fluvial strata across the bottom of the
Exploratory Trench T-1, which consisted of at least mid-Holocene to late Pleistocene
age sediments. Along the southern portion of the site, there was a 20-foot wide section
of land was unable to be trenched due to a sewer line easement (Stations 14+80 to
15+00, Sheet 5 of 6, Appendix A), but the subsurface lithologic contacts across this
untrenched span are consistent.
After all of the exploratory trenches were cleaned, examined, and logged, Mr. David
Jones (Riverside County Chief Engineering Geologist) was invited to view the trenches
and discuss our findings in the field (March 25, 2015). Additionally, prior to backfilling,
the limits of each exploratory trench excavation, along with the major fault locations,
were surveyed in our presence and under our direction by VSL Surveying, Temecula
California, for location and permanent documentation purposes. This survey data was
provided for our use in preparing the Geologic Site Map, as presented on Plate 1.
RELATIVE AGE DATING
The lacustrine deposits, primarily located within the northern portion of the site and to a
lesser extent just south of the central hill, range in age from recent to late Pleistocene in
age. The relatively thin surficial sand deposits are very recent and are underlain by
increasingly older lake deposits. These deposits are generally moderately well-
indurated to well-indurated and have formed localized disseminated CaCO3 blebs and
stringers, with occasional carbonate nodules.
The fluvial deposits within the southern portion of the site are also capped by a late
Holocene silty sand deposit, again with increasingly older deposits found at depth.
These underlying deposits are somewhat indurated and also have localized to very
abundant disseminated CaCO3 blebs and stringers and are estimated to range from the
late Holocene to possible late Pleistocene. These ages are also supported by the
abundance of grussified clasts, most all of them felsic in composition. The underlying
sedimentary bedrock materials exposed in the hilly central portion of the site have been
mapped as the Pauba Formation (Qpfs), which are Pleistocene in age (Morton and
Weber, 2003).
It should be noted that an exhaustive search for datable materials (such as organic rich
sediments and/or charcoal) was performed in both the lacustrine and fluvial deposits.
However, none were found within the excavated trench limits that could be used for
radio-carbon age-dating purposes.
TERRA GEOSCIENCES
Project No. 152772-1 Page 11
CONCLUSIONS AND RECOMMENDATIONS
GENERAL:
Based on our study and review of available pertinent literature, development of the
subject site for the proposed mobile home park appears to be feasible from a surface
fault rupture hazard standpoint, provided that our conclusions and recommendations
are considered and adhered to as outlined below.
CONCLUSIONS:
Based on review of published geologic data, field reconnaissance, photogeologic
analysis, and our subsurface exploration, faulting was observed within the limits of the
subject property as indicated on the Geologic Site Map as presented on Plate 1. The
faulting that was encountered has been assessed to be active in nature (surface ground
rupture during the past 11,000± years) based on varying localized features such as
juxtaposed Quaternary sediments against Pleistocene sedimentary bedrock of the
Pauba Formation, geomorphic expression, and the association with the active San
Elsinore Fault Zone located just to the east of the site. This activity was clearly evident
based on the offset of recent sand channel deposits (less than 1,000 years) along the
southern and central fault sections. Due to the location of the northern fault farther
towards the lake, there has been numerous erosion and depositional sequences during
high water events that have eroded sufficient evidence of recent offset sediments.
Based on our photogeologic review and our subsurface exploration, it appears that the
hill within the central portion of the site is a transpressional ridge, created by the active
movement of faults on both sides of the hill. This pressure ridge is internally highly
faulted and fractured wherein each fault splay and/or fracture, could and/or has, moved
sympathetically during previous ground rupture events that have occurred along the
major bounding faults in the relatively recent geologic past. This is evidenced by the
presence of abundant faults and fractures within the bedrock between the north and
south fault zones. Additionally, due to the lack of any overlying datable soils across the
hill (due to previous grading), the activity potentials of any of these internal faults could
not be ascertained properly.
The exploratory trench depth of 8 to 14± feet beyond the limits of the fault zones to the
north and south, was deemed appropriate for this project based on the lack of
suggestive photolineaments, soil fracturing, and/or deformation. Additionally, based on
the degree of induration, abundant accumulation of carbonate (as stringers, blebs, and
nodules), formation of clay along ped faces, and the grussified felsic clasts observed
within the sediments along the bottom of Exploratory Trench T-1, the age of these
materials may range from middle Holocene to late Pleistocene.
No datable organic materials or charcoal was found during our subsurface exploration
which could yield absolute age dates. Based on the recurrence interval of the Elsinore
Fault Zone of 450 to 750 years (Treiman, 1998), there should be numerous surface
TERRA GEOSCIENCES
Project No. 152772-1 Page 12
faulting events within these Quaternary deposits that would have occurred since they
were deposited. This suggests that there are no active faults underlying the fluvial and
lacustrine deposits, where locally explored, that are beyond the limits of the actively
faulted pressure ridge within the central portion of the subject property.
Based on our photogeologic review, it appears that the fault mapped within the southern
portion of the site by Weber (1977), County of Riverside (2000), and Morton and Weber
(2003), such as shown on Figures 2 and 3, is fairly coincident of the boundary of where
the high water lake edge has been historically located, which created a distinct
vegetation and tonal lineament. However, this lineament was not observable prior to
the more recent lake flooding event of 1980 within the 1938, 1960, and 1974 aerial
photographs reviewed. It is possible that the base geologic map prepared by Morton
and Webber, as shown on Figure 2, has been shifted around 150± feet to the north. If
the base map is shifted slightly to the south, then there is some general similarity
between this map and our findings with respect to the mapped faults and Pauba
Formation (Qpfs). The data transfer onto the base map was accomplished using map
overlays on Google Earth (2013). For illustrative purposes, Figure 5 below depicts this
observation.
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FIGURE 5- Comparison Geologic Map; from Morton and Weber (2003). The green northeast-southwest line
is the approximate trench location. The red lines are the northern and southern faults forming
the boundaries of the hill (Pauba Formation). The blue east-west trending line in the south is the
vegetation/lake edge lineament. Site outlined in purple.
TERRA GEOSCIENCES
Project No. 152772-1 Page 13
Based on the suggested misalignment of the geologic base map, of which Weber
(1977), County of Riverside (2000), and Morton and Weber (2003) used, and the
surmised lake edge lineament within the southern portion of the site, the geologic data
shown on Figure 2 does not appear to be representative of actual site conditions. The
only active faulting within the subject property where confirmed by subsurface
exploration is confined to the northern and southern margins of the central hill. This hill
appears to be a direct result of transpressional movement from motion along the
northern and south fault zone branches.
In summary, due to the lack of suggestive photolineaments, related geomorphic
features, and the absence of deformed and/or fractured Quaternary fluvial and
Iacustrine sediments, no active faulting to the north and south of the designated fault
zone (as shown on Plate 1) was observed within the limits of our exploratory trenching.
RECOMMENDATIONS:
1. Restricted-Use Zones
Restricted-Use Zones have been established within the northern and central portion
of the site, as presented on the Geologic Site Map, Plate 1. No "habitable"
structures for human occupancy (defined as 2,000 person hours per year, or as
determined by local agencies) should be constructed within the delineated
"Restricted-Use Zones." These setbacks are necessary due to the active nature of
faulting encountered during our subsurface exploration and also presumed to be
present where not trenched within the designated County Fault Zone in the north.
The central Restricted-Use Zone and associated building setback lines were
established by measuring 50 feet outward from the fault zone along a parallel
direction to the observed fault zone trend as shown on Plate 1. The northern
Restricted-Use Zone was established since the exploratory trench did not completely
traverse across the County Fault Zone boundary. Therefore, it is assumed that
there may be an active fault located just beyond the end of the trench (Station 0+00),
thus requiring a 50-foot setback. The setback line was established by measuring 50
feet southwest from the beginning of the trench (Station 0+00), parallel to the
northern fault trend.
To reduce the amount of trenching necessary towards the north portion of the site,
the client provided a conceptual map showing the project development limits.
Exploratory Trench T-1 was then excavated a conservative distance of 75 feet
beyond the proposed northern development limits to insure that the Restricted-Use
Zone would not impact any structures.
The limits of the exploratory trenches, established fault zones, and the associated
Restricted-Use Zones are considered accurate based on the provided survey data
form VSL Surveying as previously discussed.
TERRA GEOSCIENCES
Project No. 152772-1 Page 14
2. Additional Work
If any future development is proposed to encroach within the northern Restricted-
Use Zone, additional subsurface exploration would be required.
3. Trench Backfill
We understand that the exploratory trenches were backfilled in an uncompactive
and/or unsupervised manner. Periodic settling of the trenching area may occur over
time. If settlement is of concern, such as for the placement of roadways, structures,
etc., then removal and replacement of these soils as compacted fill is recommended.
Such services should be supervised by a qualified geotechnical engineer. The limits
of these trenches have been properly surveyed and can be obtained from VSL
Surveying, Temecula, California.
CLOSURE
Our conclusions and recommendations are based on a surficial field reconnaissance
limited subsurface exploration, photogeologic analysis, and an interpretation of available
existing geologic/seismic data. We make no warranty, either express or implied.
Should conditions be encountered at a later date or more information becomes
available that appear to be different than those indicated in this report, we reserve the
right to reevaluate our conclusions and recommendations and provide appropriate
mitigation measures, if warranted.
However remote, it is important to note that the potential for "new faulting" exists in the
region, due to its location to a seismically-active and complex geologic region. Collins
(1990) has described the process of "new faulting" and indicates that it is a normal
process where stress is applied to earth masses of any size. He notes that during an
earthquake, new faults can develop in several ways, such as by vertical extension (or
growth) of a pre-existing fault or fault zone; by horizontal extension of a pre-existing
fault or fault zone; by branching from a pre-existing fault or fault zone; and by faulting
related to, but not an extension or branch of, a nearby fault (e.g., faulting created within
a block of near-surface material subjected to coupling actions from nearby faults). It is
therefore prudent to assume that there is at least a remote probability that fault rupture
could occur at the site during a large nearby seismic event and that there is no way of
predicting actual possibilities and/or probable locations. Such potential occurrences of
"new faulting" should be made aware to the property owners so that they may decide on
acceptable risk levels, based on the locations of their property in relation to seismically
active areas.
It is assumed that all the conclusions and recommendations outlined in this report are
understood and followed. If any portion of this report is not understood, it is considered
to be the responsibility of the owner/contractor/engineer/governmental agency, etc., to
contact this office for further clarification.
TERRA GEOSCIENCES
GEOLOGIC SITE MAP
South 720 East
T-4 f f T ' QICount Fault Zone Limit
io QaI T-3 QIV— REESTRICTED-USE ZONE — Y
I �7+31i Ai'N-371-:50-0�1 � QI f {
� illl
?_ I n=y 3a�-�5:,-�0. Q� ( Qpf$
APN.321-29C-D02
- See Detail Below
LEGEND
F I
Qal FLUVIAL DEPOSITS
NOTE: Photolineations are coincident with fault/geologic contact j
QI LACUSTRINE DEPOSITS
- T,4 - QpfS PAUBA FORMATION
T 2 ,I �; �Q
(�1 QpfS T-3 �� �' — APP. GEOLOGIC CONTACT
FAULT (SURVEYED)
S' �'o50,
RESTRICTED- ZONE I � I_ EXPLORATORY TRENCH
QI , t Qp fs QI
RESTRICTED-USE ZONE
PROJECT NO. 152772-1 PLATE 1
i
APPENDIX A
EXPLORATORY TRENCH LOGS
LEGEND
UNIT EARTH MATERIAL ESTIMATED AGE (Epoch)
of Artificial Fill -Recent (Holocene)
LACUSTRINE DEPOSITS (QI)
A Silty Sand - Recent (Holocene)
M Sand - Recent (Holocene)
V Sand - Recent (Holocene)
Silt - Late Holocene
B Silty Sand
C Sandy Silt �- Late - Mid Holocene
D Clayey Silt
H Clayey Silty Sand
J Clayey Silty Sand Mid Holocene — Late Pleistocene
K Clayey Silty Sand J
L Clayey Silty Sand J
E Sand / Silty Sand
F Sandy Silt �- Late Pleistocene
G Silty Sand
FLUVIAL DEPOSITS (Qal)
Q Silty Sand - Late Holocene
N Silty Sand
O Silty Sand �- Mid Holocene — Late Pleistocene
P Clayey Silty Sand
PAUBA FORMATION (Qpfs)
R Sandstone
S Silty Sandstone
T Silty Sandstone
U Silty Sandstone Pleistocene
W Silty Sandstone
X Clayey Sandstone
Y Silty Sandstone J
Z Silty Sandstone J
SYMBOLS
Z Lithologic Unit
17+36 Distance Stationing (100x feet + 1x feet)
N45W/85S Fault/ Fracture / Bedding Attitude
1 Survey Point
A-1
LITHOLOGIC DESCRIPTIONS
A- SILTY SAND: Gray (2.5Y 5/1), fine- to coarse-grained with trace of gravel, loose N- SILTY SAND: Olive Brown (2.5Y 4/3), fine- to coarse-grained with minor clay, massive,
dry, slightly stratified, non cohesive, rootlets present, recent lake bottom sediments. very dense, moist, cohesive, occasional caliche blebs (<'/8")
B- SILTY SAND: Brown (10YR 5/3), fine-coarse grained, trace of fine gravel, moderately indurated, O- SILTY SAND: Olive Brown (2.5Y 4/3), fine- to coarse-grained, moist, cohesive, massive,
abundant caliche, moist, slightly cohesive, slightly blocky soil structure. dense/indurated, abundant as stringers.
C- SANDY SILT: Olive Brown (2.5Y 4/3, fine- grained with minor clay, very moist, cohesive, massive, P- CLAYEY SILTY SAND: Dark Olive Brown (2.5Y 3/3), fine-grained, moist, cohesive, massive,
very firm/indurated, upper24± inches has CaCO3 stringers, clay along ped faces. firm/indurated, abundant disseminated CaCO3 (small blebs and as stringers).
D- CLAYEY SILT: Olive (5Y 4/3), fine- grained, very moist, cohesive, occasional roots, prismatic Q- SILTY SAND: Very Dark Grayish Brown (2.5Y 4/3), fine- to coarse-grained, moist, rootlets
structure, very firm/indurated, minor disseminated CaCO3 (small blebs and as stringers). present, loose, non cohesive, massive structure, porous.
E- SAND & SILTY SAND: Grayish Brown (2.5Y 5/2), fine-coarse grained, dense/moderately indurated, R- SANDSTONE: Yellowish Brown (10YR 5/4), fine- to coarse-grained, indurated, interbeds of
well stratified, thinly layered, damp, non-cohesive, occasional orange-stained fine sand lenses. silty sandstone, well stratified, relatively thinly layered.
F- SANDY SILT: Olive Gray (5Y 5/2), fine- grained, damp, non cohesive, very firm/indurated, S- SILTY SANDSTONE: Light Olive Brown (2.5Y 5/3), fine- to coarse-grained, generally massive,
well stratified, thinly layered. trace of fine gravel, well indurated, minor CaCO3.
G- SILTY SAND: Light Olive Brown (2.5Y 5/3), fine-coarse grained, abundant fine gravel, damp, massive, T- SILTY SANDSTONE: Yellowish Brown (10YR 5/4), fine- to coarse-grained, trace of clay,
occasional grussified clasts, non cohesive, very dense/indurated, slight mottling with minor CaCO3. slightly indurated, massive structure.
H- CLAYEY SILTY SAND: Very Dark Grayish Brown (2.5Y 5/2), fine-coarse grained, moist, cohesive, U- SILTY SANDSTONE: Yellowish Brown (10YR 5/4), fine- to coarse-grained, minor gravel,
abundant caliche blebs (to '/4"), massive structure, very firm/indurated. slightly stratified, thinly layered, occasional fine-medium grained sand lenses.
I- SILT: Dark Grayish Brown (2.5Y 4/2), fine- grained, moist, moderately cohesive, rootlets present, V- SAND: Brown (10YR 5/3), fine- to coarse-grained with minor gravel, dry, loose, non cohesive,
massive to slightly prismatic soil structure, slightly firm. minor gravel, well stratified, thinly layered, minor silt.
J- CLAYEY SILTY SAND: Olive Brown (2.5Y 4/3), fine grained, trace of caliche blebs (to '/4"), moist, W- SILTY SANDSTONE: Brown (10YR 5/3), fine- to coarse-grained, massive, highly fractured,
cohesive, very firm/indurated, occasional carbonate nodules, clay along ped faces. occasional small pebbles, moderately-well indurated.
K- CLAYEY SILTY SAND: Olive Brown (2.5Y 4/4), fine-grained, moist, cohesive, minor caliche blebs, X- CLAYEY SANDSTONE: Brown (7.5YR 5/4), fine- to coarse-grained, indurated, massive,
Slightly blocky structure, firm/indurated, occasional carbonate nodules, clay along ped faces. roots present from adjacent trees, forms argillic horizon.
L- CLAYEY SILTY SAND: Olive Gray (2.5Y 5/2), fine-grained, moist, cohesive, massive structure, Y- SILTY SANDSTONE: Light Olive Brown (2.5Y 5/3), fine- to coarse-grained, well stratified, with
firm/indurated, abundant disseminated CaCO3 (small blebs and as stringers). numerous thin sandstone lenses, slightly-indurated, thinly layered, occasional grussified gravels.
M- SAND: Grayish Brown (2.5Y 5/2), fine- to coarse-grained, well stratified, thinly layered, dry, loose Z- SILTY SANDSTONE: Variegated, fine- to coarse-grained, forms a highly sheared zone with
non cohesive, occasional gravel, bedding is nearly horizontal. numerous vertical closely-spaced fractures, slightly friable, overall mottled appearance.
A-2
EXPLORATORY TRENCH T-1
< Northeast - Southwest >
0+00 ele. 1241' 1+20
/ 0+20 0+40 0+60 0+80 1+00
A
B
B
1+40
1+60 1+80 2+00 2+20 2+40
1+20
r777 A
B B
3+00 3+20
3+40 3+60
2+40 2+60 2+80 • .
A • '
. •
Sand Lens G
B. N50W/23N B. N53W/25N
SCALE 1" = 8' (Horizontal & Vertical) A-3 SHEET 1 of 6
EXPLORATORY TRENCH T-1
< Northeast - Southwest >
IFault Zone 00 4+80
4+20 e1e. 1257'�
4+40 4+60
I
4+00 of T
3+60 3+80 R R S
---------- A .
G
G I Silt Lens F. N60W/85N
do goo ' C' F. N66W/33N
60 do
do
Fine Sand Lens
B. N54W/28N
6+00
5+80
X W
5+60
ele. 1270',
of W
5+40
5+20 V F. N58W/84S
4+80 5+00 U
of S S F. N57W/90S
F. N58W/80S
F. N55W/86S Sandy Silt Lens
SCALE 1" = 8' (Horizontal & Vertical) A-4 SHEET 2 of 6
EXPLORATORY TRENCH T-1
< Northeast - Southwest >
6+00 6+20 6+40 6+60 ele. 1281'
of X 6+80
w
W X
7+00
F. N44W/72N X
F. N39W/85N
F. N40W/59N of 7+20
w X
F. N43W/85N
X
7+20 Fault Zone I
7+40 ele. 1265'\1 7+60 7+80 8+00 8+20 8+40
X of
of
w X
w M I I
� -•� H
Y
N J
F. N46W/75S •• Y 1 N
F. N25W/75N
F. N44W/85S F. N68W/83S Facies Contact
SCALE 1" = 8' (Horizontal & Vertical) A-5 SHEET 3 of 6
EXPLORATORY TRENCH T-1
< Northeast - Southwest >
8+40 8+60 8+80 9+00 9+20 9+40 9+60
of of
I
I
J L
J
9+60 9+80 10+00 10+20 10+40 10+60 10+80
of of
I I
P p
Facies Contact
10+80 11+00 11+20 11+40 11+60 11+80 12+00
of
Q
I I
O
P P
Facies Contact
SCALE 1" = 8' (Horizontal & Vertical) A-6 SHEET 4 of 6
EXPLORATORY TRENCH T-1
< Northeast - Southwest >
NOTE: Upper 8" - 12" Ground Disturbed
12+00 12+20 12+40 12+60 12+80 13+00 13+20
Q Q
O O
P P
NOTE: Upper 8" - 12" Ground Disturbed
13+20 13+40 13+60 13+80 14+00 14+20 14+40
Q Q
O
P
14+80 15+00 NOTE: Upper 8" - 12" Ground Disturbed
14+40 14+60 Sewer Easement ele. 1266' 15+20 15+40 15+60
Q Q
SEWER
O • O
P
P
SCALE 1" = 8' (Horizontal & Vertical) A-7 SHEET 5 of 6
EXPLORATORY TRENCH T-1
< Northeast - Southwest >
NOTE: Upper 8" - 12" Ground Disturbed 16+20 16+40 16+60 16+80
15+80 16+00
15+60
Q
Q
O
O
NOTE: Upper 8" - 12" Ground Disturbed 17+36
+00 17+20 ele. 1271'
16+80 171
Q
O
SCALE 1" = 8' (Horizontal & Vertical) A-8 SHEET 6 of 6
EXPLORATORY TRENCHES T-2 through T-4
< Northeast - Southwest > 0+50
T-2 0+60 T-3
0+00 0+20 0+40
0+25
of of
A 0+00
-- - G I R --
W
Silt Layer F. N52W/75S
F. N46W/68N Sand Lens
F. N61W/81S
DETAIL: TRENCH T-4
0+48 0+55
of
0+00 T-4
0+25
I
Y 0+75 M
of
Silt Lens
M Y
Sand Lens N
Z
See Detail
SCALE 1" =2' (Horizontal &Vertical) N
Colluvial Backfill
\ F. N65W/81 S
SCALE 1" = 8' (Horizontal & Vertical) A-9 SHEET 1 of 1
i
APPENDIX B
SITE PHOTOGRAPHS
SITE PHOTOGRAPHS
y.
t -
View looking southwesterly along Exploratory Trench T-1
i
• S k
• y .` R. 4Z `� y .
View looking northeasterly along Exploratory Trench T-1
B-1
SITE PHOTOGRAPHS
+3 ii
03/18/2015
t - `
View looking northeasterly(from Station 6+00)along Exploratory Trench T-1
t.
t
-
.,,.� � � c _ /._ .�•5-Jj Ifl(yJ chi
t
View looking southwesterly (from Station 6+25) along Exploratory Trench T-1
B-2
SITE PHOTOGRAPHS
d..
a
� w
View looking southwesterly along Exploratory Trench T-2
b' F
4j a
f
View looking southwesterly along Exploratory Trench T-3
B-3
SITE PHOTOGRAPHS
ti.
i
F t
View looking northeasterly along Exploratory Trench T-4
B-4
i
APPENDIX C
REFERENCES
REFERENCES
Avery, T.E., and Graydon, L.B., 1985, Interpretation of Aerial Photographs, MacMillan
Publishing Co., New York, Fourth Edition, 554 pp.
Bryant, W.A. and Hart, E.W., 2007, "Fault Rupture Hazard Zones in California,"
California Division of Mines & Geology Special Publication 42, Interim Revision 2007.
California Division of Mines & Geology (C.D.M.G.), 1978, Fault Evaluation Report FER-
72, 94pp.
California Division of Mines & Geology (C.D.M.G.), 1979, Supplement No. 1 to Fault
Evaluation Report FER-72, 16pp.
California Division of Mines & Geology (C.D.M.G.), 1986, "Guidelines to Geo-
logic/Seismic Reports," Note No. 42.
California Geological Survey (C.G.S.), 2008, Guidelines for Evaluating and Mitigating
Seismic Hazards, in California C.D.M.G. Special Publication 117.
Cao, T., Bryant, W.A., Rowshandel, B., Branum, D., and Wills, C.J., 2003, The Revised
2002 California Probabilistic Seismic Hazard Maps, June 2003, California Geological
Collins, T.K., 1990, New Faulting and the Attenuation of Fault Displacement, in Bulletin
of the Association of Engineering Geologists, Volume XXVII, Number 1, pp. 11-22.
County of Riverside, 2000, Technical Guidelines for Review of Geotechnical and
Geologic Reports, Transportation and Land Management Agency, 66 pp.
Dudley, Paul H., 1936, Physiographic History of a Portion of the Perris Block, Southern
California, from "Journal of Geology," 1936, Volume 44, pp. 358-378.
Engel, R., 1959, Geology and Mineral Deposits of the Lake Elsinore Quadrangle,
California, C.D.M.G. Bulletin 146.
Elsinore Valley Municipal Water District (E.V.M.W.D.), 2015, Lake Levels,
http://www.evmwd.com/depts/admin/public_affairs/lake levels/default.asp.
Harden, J.W., 1982, A Quantitative Index of Soil Development from Field Descriptions:
Examples from a Chronosequence in Central California: Geoderma, v. 28, pp. 1-
28.fornia, in, Bulletin of the Seismological Society of America, Vol. 82, No. 2, pp. 800-
818, April 1992.
Hathaway, Allen W., and Leighton, F. Beach, 1979, Trenching as an Exploratory
Method, Geologic Society of America, Reviews in Engineering Geology, Volume II,
Pages 169-195.
Holden, Richard, and Real, Charles, 1990, Seismic Hazards Information Needs of the
Insurance Industry, Local Government, and Property Owners in California; An Analysis,
C.D.M.G. Special Publication 108.
Hull, A.G. and Nicholson, C., 1992, Seismotectonics of the Northern Elsinore Fault
Zone, Southern Cali Survey.
Kennedy, Michael P., 1977, Recency and Character of Faulting Along the Elsinore Fault
Zone in Southern Riverside County, California, C.D.M.G. Special Report 131.
Knecht, A.A., 1971, Soil Survey of Western Riverside Area, California, Sheet Number
126.
Lamar, D.L. and Swanson, S.C., 1981, Study of Seismic Activity by Selective Trenching
along the Elsinore Fault Zone, Southern California, U.S.G.S. Open-File Report 81-0882.
Larson, R., and Slosson, J., 1992, The Role of Seismic Hazard Evaluation in Engineer-
ing Reports, in Engineering Geology Practice in Southern California, AEG Special Pub-
lication No. 4, pp. 191-194.
Mann, John, F.J., 1955, Geology of a Portion of the Elsinore Fault Zone, California,
C.D.M.G. Special Report 43.
Rockwell, T.K., and Lamar, D.L., 1986, Neotectonics of the Elsinore Fault, Southern
California, in Geological Society of America Guidebook, Neotectonics and Faulting in
Southern California, March 1986, pp. 149-208.
Ron, H., Beroza, G., and Nur, A., 2001, Simple Model Explains Complex Faulting, in
EOS, Transaction, American Geophysical Union, Volume 82, Number 10, March 6,
2001, pp. 125-129.
Shlemon, R.J., 1985, Application of Soil Stratigraphic Techniques to Engineering Geol-
ogy, in Bulletin of the Association of Engineering Geologists, Volume XXII, No. 2, 1985,
pp. 129-142.
Treiman, J., compiler, 1998, Fault number 126d, Elsinore Fault Zone, Temecula
Section, in Quaternary Fault and Fold database of the United States: U.S. Geological
Survey Website, http://earthquakes.usgs.gov/hazards/gfauIts.
U.S. Department of the Interior, Bureau of Reclamation, "Engineering Geology Field
Manual," undated, distributed 1989, 598 pp.
Weber, F. Harold, 1977, Seismic Hazards Related to Geologic Factors, Elsinore and
Chino Fault Zones, Northwestern Riverside County, California, C.D.M.G. Open File Re-
port 77-4 LA, 96 pp.
Woodford, A., Shelton, J., Doehring, D., and Morton, R., 1971, Pliocene-Pleistocene
History of the Perris Block, Southern California, Geological Society of America Bulletin,
V. 82, pp. 3421-3448, 18 Figures, December, 1971.
Ziony, J.I., and Yerkes, R.F., 1985, Evaluating Earthquake and Surface Faulting Poten-
tial, in Evaluating Earthquake Hazards in the Los Angeles Region, U.S.G.S. Profes-
sional Paper 1360.
MAPS UTILIZED
California Geological Survey, 2010, Geologic Compilation of Quaternary Surficial
Deposits in Southern California, Santa Ana 30' X 60' Quadrangle, CGS Special Report
217, Plate 16, Scale 1:100,000.
California Division of Mines and Geology, 1980, Elsinore 7.5' Earthquake Fault Zone
Map, Scale 1" = 2,000'.
GoogleTm Earth, 2013, http://earth.google.com/, Version 7.1.2.2041.
Gray, C.H. Jr., 1954, Geology of the Corona-Elsinore-Murrieta Area, Riverside County,
Map Sheet No. 21, C.D.M.G. Bulletin 170, Vol. 1 & 2, Scale 1" = 3 miles.
Greenwood, R.B., and Morton, D.M., 1991, Geologic Map of the Santa Ana 1:100,000
Quadrangle, California, and C.D.M.G. Open File Report 91-17.
Jennings, C.W., 1992, Preliminary Fault Activity Map of California, Scale 1:750,000,
C.D.M.G. Open File Report 92-03.
Jennings, C.W. and Bryant, W.A., 2010, 2010 Fault Activity Map of California, California
Geological Survey Geologic Data Map No. 6, Scale 1:750,000
Morton, D.M. and Weber, F.H. Jr., 1990, Geologic Map of the Elsinore Quadrangle,
Riverside Count, California, U.S.G.S. Open-File Report 90-0700, Scale 1:24,000.
Morton, D.M., 1999, Preliminary Digital Geologic Map of the Santa Ana 30' x 60'
Quadrangle, Southern California, Version 1.0, U.S.G.S. Open-File Report OFR 99-172,
Scale 1:100,000.
Morton, D.M. and Weber, F.H. Jr., 2003, Preliminary Geologic Map of the Elsinore
Quadrangle, Riverside County, California, U.S.G.S. Open-File Report 03-281, Scale
1:24,000.
Morton, D.M. and Miller, F.K., 2006, Geologic Map of the San Bernardino and Santa
Ana 30' x 60' Quadrangles, California, U.S.G.S. Open-File Report 2006-1217, Scale
1:1000,000.
Jennings, C.W., 1992, Preliminary Fault Activity Map of California, Scale 1:750,000,
C.D.M.G. Open File Report 92-03.
Rodgers, T.H., 1966, Geologic Map of California, Santa Ana Sheet, Scale 1:250,000
(Second Printing 1973).
United States Geological Survey (U.S.G.S.), 1997, Lake Elsinore 7.5' Quadrangle,
Riverside County, California, Scale 1:24,000.
Ziony, J.I., and Jones, L.M., 1989, Map Showing Late Quaternary Faults and 1978-1984
Seismicity of the Los Angeles Region, California, U.S.G.S. Miscellaneous Field Studies
Map MF-1964.
AERIAL PHOTOGRAPHS
Riverside County Flood Control District, 1960, Photo Numbers 45 through 47, Scale
1"=1,000', dated September 6, 1960.
Riverside County Flood Control District, 1974, Photo Numbers 724 and 725, Scale
1"=2,000', dated June 20, 1974.
Riverside County Flood Control District, 1980, Photo Numbers 754 through and 756,
Scale 1"=2,000', dated May 4, 1980.
Riverside County Flood Control District, 1990, Photo Numbers 14-10 and 14-11, Scale
1"=1,600', dated January 22, 1990.
Riverside County Flood Control District, 2000, Photo Numbers 14-9 through 14-11,
Scale 1"=1,600', dated March 18, 2000.
Riverside County Flood Control District, 2005, Photo Numbers 14-9 through 14-11,
Scale 1"=1,600', dated April 13, 2005.
Riverside County Flood Control District, 2010, Photo Numbers 14-9 and 14-10, Scale
1"=1,600', color, dated April 2, 2010.
U.S.D.A., 1938, Photo Nos. AXM-31-20 and AXM-31-218, Scale 1" = 1,667', dated May
24, 1938.
APPENDIX 4
�
RECOMMENDED GRADING SPECIFICATIONS
1. GENERAL
1.1 These Recommended Grading Specifications shall be used in conjunction with the
Geotechnical Report for the project prepared by Geocon. The recommendations contained
in the text of the Geotechnical Report are a part of the earthwork and grading specifications
and shall supersede the provisions contained hereinafter in the case of conflict.
1.2 Prior to the commencement of grading, a geotechnical consultant (Consultant) shall be
employed for the purpose of observing earthwork procedures and testing the fills for
substantial conformance with the recommendations of the Geotechnical Report and these
specifications. The Consultant should provide adequate testing and observation services so
that they may assess whether, in their opinion, the work was performed in substantial
conformance with these specifications. It shall be the responsibility of the Contractor to
assist the Consultant and keep them apprised of work schedules and changes so that
personnel may be scheduled accordingly.
1.3 It shall be the sole responsibility of the Contractor to provide adequate equipment and
methods to accomplish the work in accordance with applicable grading codes or agency
ordinances, these specifications and the approved grading plans. If, in the opinion of the
Consultant, unsatisfactory conditions such as questionable soil materials, poor moisture
condition, inadequate compaction, and/or adverse weather result in a quality of work not in
conformance with these specifications, the Consultant will be empowered to reject the
work and recommend to the Owner that grading be stopped until the unacceptable
conditions are corrected.
2. DEFINITIONS
2.1 Owner shall refer to the owner of the property or the entity on whose behalf the grading
work is being performed and who has contracted with the Contractor to have grading
performed.
2.2 Contractor shall refer to the Contractor performing the site grading work.
2.3 Civil Engineer or Engineer of Work shall refer to the California licensed Civil Engineer
or consulting firm responsible for preparation of the grading plans, surveying and verifying
as-graded topography.
2.4 Consultant shall refer to the soil engineering and engineering geology consulting firm
retained to provide geotechnical services for the project.
GI rev.07/2015
2.5 Soil Engineer shall refer to a California licensed Civil Engineer retained by the Owner,
who is experienced in the practice of geotechnical engineering. The Soil Engineer shall be
responsible for having qualified representatives on-site to observe and test the Contractor's
work for conformance with these specifications.
2.6 Engineering Geologist shall refer to a California licensed Engineering Geologist retained
by the Owner to provide geologic observations and recommendations during the site
grading.
2.7 Geotechnical Report shall refer to a soil report(including all addenda)which may include
a geologic reconnaissance or geologic investigation that was prepared specifically for the
development of the project for which these Recommended Grading Specifications are
intended to apply.
3. MATERIALS
3.1 Materials for compacted fill shall consist of any soil excavated from the cut areas or
imported to the site that, in the opinion of the Consultant, is suitable for use in construction
of fills. In general, fill materials can be classified as soil fills,soil-rock fills or rock fills, as
defined below.
3.1.1 Soil fills are defined as fills containing no rocks or hard lumps greater than
12 inches in maximum dimension and containing at least 40 percent by weight of
material smaller than 3/4 inch in size.
3.1.2 Soil-rock fills are defined as fills containing no rocks or hard lumps larger than
4 feet in maximum dimension and containing a sufficient matrix of soil fill to allow
for proper compaction of soil fill around the rock fragments or hard lumps as
specified in Paragraph 6.2. Oversize rock is defined as material greater than
12 inches.
3.1.3 Rock fills are defined as fills containing no rocks or hard lumps larger than 3 feet
in maximum dimension and containing little or no fines. Fines are defined as
material smaller than 3/4 inch in maximum dimension. The quantity of fines shall be
less than approximately 20 percent of the rock fill quantity.
3.2 Material of a perishable, spongy, or otherwise unsuitable nature as determined by the
Consultant shall not be used in fills.
3.3 Materials used for fill, either imported or on-site, shall not contain hazardous materials as
defined by the California Code of Regulations, Title 22, Division 4, Chapter 30, Articles 9
GI rev.07/2015
and 10; 40CFR; and any other applicable local, state or federal laws. The Consultant shall
not be responsible for the identification or analysis of the potential presence of hazardous
materials. However, if observations, odors or soil discoloration cause Consultant to suspect
the presence of hazardous materials, the Consultant may request from the Owner the
termination of grading operations within the affected area. Prior to resuming grading
operations, the Owner shall provide a written report to the Consultant indicating that the
suspected materials are not hazardous as defined by applicable laws and regulations.
3.4 The outer 15 feet of soil-rock fill slopes, measured horizontally, should be composed of
properly compacted soil fill materials approved by the Consultant. Rock fill may extend to
the slope face,provided that the slope is not steeper than 2:1 (horizontal:vertical) and a soil
layer no thicker than 12 inches is track-walked onto the face for landscaping purposes. This
procedure may be utilized provided it is acceptable to the governing agency, Owner and
Consultant.
3.5 Samples of soil materials to be used for fill should be tested in the laboratory by the
Consultant to determine the maximum density, optimum moisture content, and, where
appropriate, shear strength,expansion,and gradation characteristics of the soil.
3.6 During grading, soil or groundwater conditions other than those identified in the
Geotechnical Report may be encountered by the Contractor. The Consultant shall be
notified immediately to evaluate the significance of the unanticipated condition
4. CLEARING AND PREPARING AREAS TO BE FILLED
4.1 Areas to be excavated and filled shall be cleared and grubbed. Clearing shall consist of
complete removal above the ground surface of trees, stumps, brush, vegetation, man-made
structures, and similar debris. Grubbing shall consist of removal of stumps, roots, buried
logs and other unsuitable material and shall be performed in areas to be graded. Roots and
other projections exceeding 1'/2 inches in diameter shall be removed to a depth of 3 feet
below the surface of the ground. Borrow areas shall be grubbed to the extent necessary to
provide suitable fill materials.
4.2 Asphalt pavement material removed during clearing operations should be properly
disposed at an approved off-site facility or in an acceptable area of the project evaluated by
Geocon and the property owner. Concrete fragments that are free of reinforcing steel may
be placed in fills, provided they are placed in accordance with Section 6.2 or 6.3 of this
document.
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4.3 After clearing and grubbing of organic matter and other unsuitable material, loose or
porous soils shall be removed to the depth recommended in the Geotechnical Report. The
depth of removal and compaction should be observed and approved by a representative of
the Consultant. The exposed surface shall then be plowed or scarified to a minimum depth
of 6 inches and until the surface is free from uneven features that would tend to prevent
uniform compaction by the equipment to be used.
4.4 Where the slope ratio of the original ground is steeper than 5:1 (horizontal:vertical), or
where recommended by the Consultant, the original ground should be benched in
accordance with the following illustration.
TYPICAL BENCHING DETAIL
Finish Grade Original Ground
2
�1
Finish Slope Surface
Remove All
Unsuitable Material
As Recommended By
Consultant Slope To Be Such That
Sloughing Or Sliding
Does Not Occur Varies
"B„
See Note 1 See Note 2
No Scale
DETAIL NOTES: (1) Key width "B" should be a minimum of 10 feet, or sufficiently wide to permit
complete coverage with the compaction equipment used. The base of the key should
be graded horizontal,or inclined slightly into the natural slope.
(2) The outside of the key should be below the topsoil or unsuitable surficial material
and at least 2 feet into dense formational material.Where hard rock is exposed in the
bottom of the key, the depth and configuration of the key may be modified as
approved by the Consultant.
4.5 After areas to receive fill have been cleared and scarified, the surface should be moisture
conditioned to achieve the proper moisture content, and compacted as recommended in
Section 6 of these specifications.
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5. COMPACTION EQUIPMENT
5.1 Compaction of soil or soil-rock fill shall be accomplished by sheepsfoot or segmented-steel
wheeled rollers, vibratory rollers, multiple-wheel pneumatic-tired rollers, or other types of
acceptable compaction equipment. Equipment shall be of such a design that it will be
capable of compacting the soil or soil-rock fill to the specified relative compaction at the
specified moisture content.
5.2 Compaction of rock fills shall be performed in accordance with Section 6.3.
6. PLACING, SPREADING AND COMPACTION OF FILL MATERIAL
6.1 Soil fill, as defined in Paragraph 3.1.1, shall be placed by the Contractor in accordance with
the following recommendations:
6.1.1 Soil fill shall be placed by the Contractor in layers that, when compacted, should
generally not exceed 8 inches. Each layer shall be spread evenly and shall be
thoroughly mixed during spreading to obtain uniformity of material and moisture
in each layer. The entire fill shall be constructed as a unit in nearly level lifts. Rock
materials greater than 12 inches in maximum dimension shall be placed in
accordance with Section 6.2 or 6.3 of these specifications.
6.1.2 In general, the soil fill shall be compacted at a moisture content at or above the
optimum moisture content as determined by ASTM D 1557.
6.1.3 When the moisture content of soil fill is below that specified by the Consultant,
water shall be added by the Contractor until the moisture content is in the range
specified.
6.1.4 When the moisture content of the soil fill is above the range specified by the
Consultant or too wet to achieve proper compaction,the soil fill shall be aerated by
the Contractor by blading/mixing, or other satisfactory methods until the moisture
content is within the range specified.
6.1.5 After each layer has been placed, mixed, and spread evenly, it shall be thoroughly
compacted by the Contractor to a relative compaction of at least 90 percent.
Relative compaction is defined as the ratio (expressed in percent) of the in-place
dry density of the compacted fill to the maximum laboratory dry density as
determined in accordance with ASTM D 1557. Compaction shall be continuous
over the entire area, and compaction equipment shall make sufficient passes so that
the specified minimum relative compaction has been achieved throughout the
entire fill.
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6.1.6 Where practical, soils having an Expansion Index greater than 50 should be placed
at least 3 feet below finish pad grade and should be compacted at a moisture
content generally 2 to 4 percent greater than the optimum moisture content for the
material.
6.1.7 Properly compacted soil fill shall extend to the design surface of fill slopes. To
achieve proper compaction, it is recommended that fill slopes be over-built by at
least 3 feet and then cut to the design grade. This procedure is considered
preferable to track-walking of slopes, as described in the following paragraph.
6.1.8 As an alternative to over-building of slopes, slope faces may be back-rolled with a
heavy-duty loaded sheepsfoot or vibratory roller at maximum 4-foot fill height
intervals. Upon completion, slopes should then be track-walked with a D-8 dozer
or similar equipment, such that a dozer track covers all slope surfaces at least
twice.
6.2 Soil-rock fill, as defined in Paragraph 3.1.2, shall be placed by the Contractor in accordance
with the following recommendations:
6.2.1 Rocks larger than 12 inches but less than 4 feet in maximum dimension may be
incorporated into the compacted soil fill, but shall be limited to the area measured
15 feet minimum horizontally from the slope face and 5 feet below finish grade or
3 feet below the deepest utility,whichever is deeper.
6.2.2 Rocks or rock fragments up to 4 feet in maximum dimension may either be
individually placed or placed in windrows. Under certain conditions, rocks or rock
fragments up to 10 feet in maximum dimension may be placed using similar
methods. The acceptability of placing rock materials greater than 4 feet in
maximum dimension shall be evaluated during grading as specific cases arise and
shall be approved by the Consultant prior to placement.
6.2.3 For individual placement, sufficient space shall be provided between rocks to allow
for passage of compaction equipment.
6.2.4 For windrow placement, the rocks should be placed in trenches excavated in
properly compacted soil fill. Trenches should be approximately 5 feet wide and
4 feet deep in maximum dimension. The voids around and beneath rocks should be
filled with approved granular soil having a Sand Equivalent of 30 or greater and
should be compacted by flooding. Windrows may also be placed utilizing an
"open-face" method in lieu of the trench procedure, however, this method should
first be approved by the Consultant.
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6.2.5 Windrows should generally be parallel to each other and may be placed either
parallel to or perpendicular to the face of the slope depending on the site geometry.
The minimum horizontal spacing for windrows shall be 12 feet center-to-center
with a 5-foot stagger or offset from lower courses to next overlying course. The
minimum vertical spacing between windrow courses shall be 2 feet from the top of
a lower windrow to the bottom of the next higher windrow.
6.2.6 Rock placement, fill placement and flooding of approved granular soil in the
windrows should be continuously observed by the Consultant.
6.3 Rock fills, as defined in Section 3.1.3, shall be placed by the Contractor in accordance with
the following recommendations:
6.3.1 The base of the rock fill shall be placed on a sloping surface (minimum slope of 2
percent). The surface shall slope toward suitable subdrainage outlet facilities. The
rock fills shall be provided with subdrains during construction so that a hydrostatic
pressure buildup does not develop. The subdrains shall be permanently connected
to controlled drainage facilities to control post-construction infiltration of water.
6.3.2 Rock fills shall be placed in lifts not exceeding 3 feet. Placement shall be by rock
trucks traversing previously placed lifts and dumping at the edge of the currently
placed lift. Spreading of the rock fill shall be by dozer to facilitate seating of the
rock. The rock fill shall be watered heavily during placement. Watering shall
consist of water trucks traversing in front of the current rock lift face and spraying
water continuously during rock placement. Compaction equipment with
compactive energy comparable to or greater than that of a 20-ton steel vibratory
roller or other compaction equipment providing suitable energy to achieve the
required compaction or deflection as recommended in Paragraph 6.3.3 shall be
utilized. The number of passes to be made should be determined as described in
Paragraph 6.3.3. Once a rock fill lift has been covered with soil fill, no additional
rock fill lifts will be permitted over the soil fill.
6.3.3 Plate bearing tests, in accordance with ASTM D 1196, may be performed in both
the compacted soil fill and in the rock fill to aid in determining the required
minimum number of passes of the compaction equipment. If performed, a
minimum of three plate bearing tests should be performed in the properly
compacted soil fill (minimum relative compaction of 90 percent). Plate bearing
tests shall then be performed on areas of rock fill having two passes, four passes
and six passes of the compaction equipment, respectively. The number of passes
required for the rock fill shall be determined by comparing the results of the plate
bearing tests for the soil fill and the rock fill and by evaluating the deflection
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variation with number of passes. The required number of passes of the compaction
equipment will be performed as necessary until the plate bearing deflections are
equal to or less than that determined for the properly compacted soil fill. In no case
will the required number of passes be less than two.
6.3.4 A representative of the Consultant should be present during rock fill operations to
observe that the minimum number of"passes" have been obtained, that water is
being properly applied and that specified procedures are being followed. The actual
number of plate bearing tests will be determined by the Consultant during grading.
6.3.5 Test pits shall be excavated by the Contractor so that the Consultant can state that,
in their opinion, sufficient water is present and that voids between large rocks are
properly filled with smaller rock material. In-place density testing will not be
required in the rock fills.
6.3.6 To reduce the potential for "piping" of fines into the rock fill from overlying soil
fill material, a 2-foot layer of graded filter material shall be placed above the
uppermost lift of rock fill. The need to place graded filter material below the rock
should be determined by the Consultant prior to commencing grading. The
gradation of the graded filter material will be determined at the time the rock fill is
being excavated. Materials typical of the rock fill should be submitted to the
Consultant in a timely manner, to allow design of the graded filter prior to the
commencement of rock fill placement.
6.3.7 Rock fill placement should be continuously observed during placement by the
Consultant.
7. SUBDRAINS
7.1 The geologic units on the site may have permeability characteristics and/or fracture
systems that could be susceptible under certain conditions to seepage. The use of canyon
subdrains may be necessary to mitigate the potential for adverse impacts associated with
seepage conditions. Canyon subdrains with lengths in excess of 500 feet or extensions of
existing offsite subdrains should use 8-inch-diameter pipes. Canyon subdrains less than 500
feet in length should use 6-inch-diameter pipes.
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TYPICAL CANYON DRAIN DETAIL
NATURALGROUND
i
ALLUVIUM AND
COLLUVIUM
REMOVAL
T
BEDROCK
SEE DETAIL BELOW
NOTE:FINAL ZY OF PIPE AT OUTLET
SHALL BE NON•PERFORATED-
O`DIA.PERFORATED
SUBDRAM PIPE
4 ° a: � aF Ni� a - a- �.4• db a4•°
:a
4 qa e
m-a•
d•,
d.•
.a r 9 CUBIC FEET)FOOT OF OPEN
GRADED GRAVEL SURROUNDED BY
MIRAR 14ONC(OR EQUIVALENT)
FILTER FABRIC
NOTES:
1......8-INCH DIAMETER,SCHEDULE BO PVC PERFORATED PIPE FOR FILLS
IN EXCESS OF 100-FEET IN DEPTH OR A PIPE LENGTH OF LONGER THAN 500 FEET.
2......8-INCH DIAMETER,SCHEDULE 40 PVC PERFORATED PIPE FOR FILLS
LESS THAN 100-FEET IN DEPTH OR A PIPE LENGTH SHORTER THAN 500 FEET.
NO SCALE
7.2 Slope drains within stability fill keyways should use 4-inch-diameter(or larger)pipes.
GI rev.07/2015
TYPICAL STABILITY FILL DETAIL
+a
�NIN.�
2
NOTE, �+ FINISHED SLOPE
NOTE 8f
NOTE4 SEE
DEBT is, TWIN-
NOTE 5 MIN. see NOTE
FORMATIONAL
1 MATERIAL
1 NOTE 6
1
2'MIN.
1.5'
MIN.
DETAIL
NOTES:
1.....EXCAVATE BACKCUT AT 1A INCLINATION(UNLESS OTHERWISE NOTED).
2.....BASE OF STABILITY FILLTO BE 3 FEET INTO FORMATIONAL MATERIAL,SLOPINOA MNIMUM 5%WO SLOPE.
3.....STABILITY FILL TO BE COMPOSED OF PROPERLY COMPACTED GRANULAR SOIL.
4,....CHIMNEY DRAINS TO BE APPROVED PREFABRICATED CHIMNEY DRAIN PANELS(MIRADRAIN G20CN OR EQUIVALENT)
SPACED APPROXIMATELY 20 FEET CENTER TO CENTER AND 4 FEET WIDE.CLOSER SPACING MAY BE REQUIRED IF
SEEPAGE IS ENCOUNTERED.
5.....FILTER MATERIAL TO BE 3/4-INCH.OPEN-GRADED CRUSHED ROCK ENCLOSED IN APPROVED FILTER FABRIC(MIRAFI 14ONC).
B..,..COLLECTOR PIPE TO BE 4-INCH MINIMUM DIAMETER,PERFORATED,THICK-WALLED PVC SCHEDULE 40 OR
EQUIVALENT,AND SLOPED TO DRAIN AT 1 PERCENT MINIMUM TO APPROVED OUTLET.
NO SCALE
7.3 The actual subdrain locations will be evaluated in the field during the remedial grading
operations. Additional drains may be necessary depending on the conditions observed and
the requirements of the local regulatory agencies. Appropriate subdrain outlets should be
evaluated prior to finalizing 40-scale grading plans.
7.4 Rock fill or soil-rock fill areas may require subdrains along their down-slope perimeters to
mitigate the potential for buildup of water from construction or landscape irrigation. The
subdrains should be at least 6-inch-diameter pipes encapsulated in gravel and filter fabric.
Rock fill drains should be constructed using the same requirements as canyon subdrains.
GI rev.07/2015
7.5 Prior to outletting, the final 20-foot segment of a subdrain that will not be extended during
future development should consist of non-perforated drainpipe. At the non-perforated/
perforated interface, a seepage cutoff wall should be constructed on the downslope side of
the pipe.
TYPICAL CUT OFF WALL DETAIL
FRONT VIEW
W MIN.
SUBDRAIN
PIPE
j'41 .
CONCAM MIN.
CLITLOFF WALL
MIN
NO SCALE
SIDE VIEW
Tr
CONCRETE CUT-OFF r MIN.(TYP)
SOLID SUBDRAIN PIPE PERFORATED*FENrN PIPE
WV/ IX
r MIN.(TYP)
NO BGNE
7.6 Subdrains that discharge into a natural drainage course or open space area should be
provided with a permanent headwall structure.
GI rev.07/2015
TYPICAL HEADWALL DETAIL
FRONT VIEW
it
r
:r!•.•- 7.•e 1r
•� eb k
NO SCALE
SIDE VIEW
8'OR B'
SUB 1'
DRAIN ..
CONCRETEa-
HEADWALL !e•:'
:•ia':.4�e. �r
2
t 21
NOTE: HEADWALL SHOULD OUTLET AT TOE OF FILL SLOPE NO SCALE
OR INTO CONTROLLED SURFACE DRAINAGE
7.7 The final grading plans should show the location of the proposed subdrains. After
completion of remedial excavations and subdrain installation, the project civil engineer
should survey the drain locations and prepare an "as-built" map showing the drain
locations. The final outlet and connection locations should be determined during grading
operations. Subdrains that will be extended on adjacent projects after grading can be placed
on formational material and a vertical riser should be placed at the end of the subdrain. The
grading contractor should consider videoing the subdrains shortly after burial to check
proper installation and functionality. The contractor is responsible for the performance of
the drains.
GI rev.07/2015
8. OBSERVATION AND TESTING
8.1 The Consultant shall be the Owner's representative to observe and perform tests during
clearing, grubbing, filling, and compaction operations. In general, no more than 2 feet in
vertical elevation of soil or soil-rock fill should be placed without at least one field density
test being performed within that interval. In addition, a minimum of one field density test
should be performed for every 2,000 cubic yards of soil or soil-rock fill placed and
compacted.
8.2 The Consultant should perform a sufficient distribution of field density tests of the
compacted soil or soil-rock fill to provide a basis for expressing an opinion whether the fill
material is compacted as specified. Density tests shall be performed in the compacted
materials below any disturbed surface. When these tests indicate that the density of any
layer of fill or portion thereof is below that specified, the particular layer or areas
represented by the test shall be reworked until the specified density has been achieved.
8.3 During placement of rock fill, the Consultant should observe that the minimum number of
passes have been obtained per the criteria discussed in Section 6.3.3. The Consultant
should request the excavation of observation pits and may perform plate bearing tests on
the placed rock fills. The observation pits will be excavated to provide a basis for
expressing an opinion as to whether the rock fill is properly seated and sufficient moisture
has been applied to the material. When observations indicate that a layer of rock fill or any
portion thereof is below that specified, the affected layer or area shall be reworked until the
rock fill has been adequately seated and sufficient moisture applied.
8.4 A settlement monitoring program designed by the Consultant may be conducted in areas of
rock fill placement. The specific design of the monitoring program shall be as
recommended in the Conclusions and Recommendations section of the project
Geotechnical Report or in the final report of testing and observation services performed
during grading.
8.5 We should observe the placement of subdrains, to check that the drainage devices have
been placed and constructed in substantial conformance with project specifications.
8.6 Testing procedures shall conform to the following Standards as appropriate:
8.6.1 Soil and Soil-Rock Fills:
8.6.1.1 Field Density Test, ASTM D 1556, Density of Soil In-Place By the
Sand-Cone Method.
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8.6.1.2 Field Density Test,Nuclear Method, ASTM D 6938,Density of Soil and
Soil-Aggregate In-Place by Nuclear Methods (Shallow Depth).
8.6.1.3 Laboratory Compaction Test, ASTM D 1557, Moisture-Density
Relations of Soils and Soil-Aggregate Mixtures Using 10-Pound
Hammer and 18-Inch Drop.
8.6.1.4. Expansion Index Test,ASTM D 4829,Expansion Index Test.
9. PROTECTION OF WORK
9.1 During construction, the Contractor shall properly grade all excavated surfaces to provide
positive drainage and prevent ponding of water. Drainage of surface water shall be
controlled to avoid damage to adjoining properties or to finished work on the site. The
Contractor shall take remedial measures to prevent erosion of freshly graded areas until
such time as permanent drainage and erosion control features have been installed. Areas
subjected to erosion or sedimentation shall be properly prepared in accordance with the
Specifications prior to placing additional fill or structures.
9.2 After completion of grading as observed and tested by the Consultant, no further
excavation or filling shall be conducted except in conjunction with the services of the
Consultant.
10. CERTIFICATIONS AND FINAL REPORTS
10.1 Upon completion of the work, Contractor shall furnish Owner a certification by the Civil
Engineer stating that the lots and/or building pads are graded to within 0.1 foot vertically of
elevations shown on the grading plan and that all tops and toes of slopes are within 0.5 foot
horizontally of the positions shown on the grading plans. After installation of a section of
subdrain, the project Civil Engineer should survey its location and prepare an as-built plan
of the subdrain location. The project Civil Engineer should verify the proper outlet for the
subdrains and the Contractor should ensure that the drain system is free of obstructions.
10.2 The Owner is responsible for furnishing a final as-graded soil and geologic report
satisfactory to the appropriate governing or accepting agencies. The as-graded report
should be prepared and signed by a California licensed Civil Engineer experienced in
geotechnical engineering and by a California Certified Engineering Geologist, indicating
that the geotechnical aspects of the grading were performed in substantial conformance
with the Specifications or approved changes to the Specifications.
GI rev.07/2015