HomeMy WebLinkAboutCT 2017-0005; Grand West; Geotechnical Investigation for Grand West; 2017-05-31
GEOTECHNICAL INVESTIGATION
PROPOSED TWO TRIPLEX TOWNHOME CONDOMINIUMS
972 AND 988 GRAND AVENUE
CARLSBAD, CALIFORNIA
Prepared for:
MR. ERIC DEJONG
C/O: CONSULTANTS COLLABORATIVE
MS. TERRY MATHEW
160 INDUSTRIAL STREET
SAN MARCOS, CALIFORNIA 92078
Prepared by:
CONSTRUCTION TESTING & ENGINEERING, INC.
1441 MONTIEL ROAD, SUITE 115
ESCONDIDO, CALIFORNIA 92026
CTE JOB NO.: 10-13643G May 31, 2017
Construction Testing & Engineering, Inc.
Inspection I Testing I Geotechnical I Environmental & Construction Engineering I Civil Engineering I Surveying
1441 Montiel Road, Suite 115 I Escondido, CA92026 I Ph (760) 746-4955 I Fax (760) 746-9806 I www.cte-inc.net
TABLE OF CONTENTS
1.0 INTRODUCTION AND SCOPE OF SERVICES ................................................................... 1
1.1 Introduction ................................................................................................................... 1
1.2 Scope of Services .......................................................................................................... 1
2.0 SITE DESCRIPTION ............................................................................................................... 2
3.0 FIELD INVESTIGATION AND LABORATORY TESTING ................................................ 2
3.1 Field Investigation ........................................................................................................ 2
3.2 Laboratory Testing ........................................................................................................ 2
3.3 Percolation Testing ....................................................................................................... 3
3.3.1 Calculated Infiltration Rates .......................................................................... 4
3.3.2 Calculated Infiltration Rates .......................................................................... 6
4.0 GEOLOGY ............................................................................................................................... 7
4.1 General Setting ............................................................................................................. 7
4.2 Geologic Conditions ..................................................................................................... 7
4.2.1 Residual Soil .................................................................................................. 7
4.2.2 Quaternary Old Paralic Deposits (Qop) ......................................................... 8
4.3 Groundwater Conditions ............................................................................................... 8
4.4 Geologic Hazards .......................................................................................................... 8
4.4.1 Surface Fault Rupture .................................................................................... 9
4.4.2 Local and Regional Faulting .......................................................................... 9
4.4.3 Liquefaction and Seismic Settlement Evaluation ........................................ 10
4.4.4 Tsunamis and Seiche Evaluation ................................................................. 10
4.4.5 Landsliding .................................................................................................. 11
4.4.6 Compressible and Expansive Soils .............................................................. 11
4.4.7 Corrosive Soils ............................................................................................. 12
5.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................. 13
5.1 General ........................................................................................................................ 13
5.2 Site Preparation ........................................................................................................... 13
5.3 Site Excavation ........................................................................................................... 14
5.4 Fill Placement and Compaction .................................................................................. 14
5.5 Fill Materials ............................................................................................................... 15
5.6 Temporary Construction Slopes ................................................................................. 16
5.7 Foundations and Slab Recommendations ................................................................... 17
5.7.1 Foundations .................................................................................................. 17
5.7.2 Foundation Settlement ................................................................................. 18
5.7.3 Foundation Setback ...................................................................................... 18
5.7.4 Interior Concrete Slabs ................................................................................ 19
5.8 Seismic Design Criteria .............................................................................................. 20
5.9 Lateral Resistance and Earth Pressures ...................................................................... 21
5.10 Exterior Flatwork ...................................................................................................... 23
5.11 Pavements ................................................................................................................. 23
5.12 Drainage .................................................................................................................... 24
5.13 Slopes ........................................................................................................................ 25
5.14 Plan Review .............................................................................................................. 26
5.15 Construction Observation ......................................................................................... 26
6.0 LIMITATIONS OF INVESTIGATION ................................................................................. 27
TABLE OF CONTENTS
FIGURES
FIGURE 1 SITE LOCATION MAP
FIGURE 2 GEOLOGIC/ EXPLORATION LOCATION MAP
FIGURE 3 REGIONAL FAULT AND SEISMICITY MAP
FIGURE 4 CONCEPTUAL RETAINING WALL DRAINAGE
APPENDICES
APPENDIX A REFERENCES
APPENDIX B FIELD EXPLORATION METHODS LOGS
APPENDIX C LABORATORY METHODS AND RESULTS
APPENDIX D STANDARD GRADING SPECIFICATIONS
APPENDIX E C.4-1 WORKSHEET
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1.0 INTRODUCTION AND SCOPE OF SERVICES
1.1 Introduction
This report presents the results of the geotechnical investigation, performed by Construction Testing
and Engineering, Inc. (CTE), and provides preliminary conclusions and recommendations for the
proposed improvements at the subject site located in Carlsbad, California. This investigation was
performed in general accordance with the terms of CTE proposal G-4029A, dated March 27, 2017.
CTE understands that the proposed site improvements are to consist of two structures of two- to
three-story construction, paved parking and flatwork, retention basins, associated utilities,
landscaping, and ancillary improvements. Preliminary recommendations for excavations, fill
placement, and foundation design for the proposed improvements are presented in this report.
Reviewed references are provided in Appendix A.
1.2 Scope of Services
The scope of services provided included:
Review of readily available geologic and geotechnical reports.
Excavation of exploratory borings utilizing limited-access manually operated drilling equipment.
Percolation testing in accordance with County of San Diego Department of Environmental
Health (DEH) procedures.
Laboratory testing of selected soil samples.
Description of site geology and evaluation of potential geologic hazards.
Engineering and geologic analysis.
Preparation of this geotechnical investigation report.
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2.0 SITE DESCRIPTION
The project site is located at 972 and 988 Grand Avenue in Carlsbad, California (Figure 1). The site
is bounded by Grand Avenue to the southeast and residences on all other sides. The project area is
generally flat at an approximate elevation of 68 feet msl (above mean sea level).
3.0 FIELD INVESTIGATION AND LABORATORY TESTING
3.1 Field Investigation
CTE performed the field investigation on May 9, 2017. The field work consisted of a site
reconnaissance and excavation of four exploratory borings and four percolation test holes. The
borings were excavated with a manually operated three-inch diameter auger. Bulk samples were
collected from the cuttings.
The soils were logged in the field by a CTE Engineering Geologist, and were classified in general
accordance with the Unified Soil Classification System via visual and tactile methods. The field
descriptions have been modified, where appropriate, to reflect laboratory test results. Boring logs,
including descriptions of the soils encountered, are included in Appendix B. The approximate
locations of the borings are presented on Figure 2.
3.2 Laboratory Testing
Laboratory tests were conducted on selected soil samples for classification purposes, and to evaluate
physical properties and engineering characteristics. Laboratory tests included: Gradation, Expansion
Index (EI), and Chemical Characteristics. Test descriptions and laboratory test results for the
selected soils are included in Appendix C.
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3.3 Percolation Testing
The percolation testing was performed in accordance with SD DEH Case III method, which is
performed when presoak water infiltrates through the hole overnight. The presoak duration for all
tests ranged from approximately 23 to 24 hours, which is within the SD DEH 15 to 30 hour presoak
range. Percolation test results and rates are presented below in Table 3.3. The C.4-1 infiltration
feasibility worksheet is also included in Appendix E.
TABLE 3.3
PERCOLATION RATES
Boring/Depth
(inches)
P-1/51.0
Soil:
Qop
Case III
Time Time
Change
(minutes)
Initial Water
Level
(inches)
Final Water
Level
(inches)
Water Level
Change
(inches)
Percolation Rate
Inches/
Hour
Inches
/
Minut
e
0930 Initial 43.0 N/A N/A
1.5
0.025
1000 30 43.0 44.1875 1.19
1030 60 43.0 43.875 0.88
1100 90 43.875 44.75 0.88
1130 120 43.0 44.25 1.25
1200 150 43.0 43.75 0.75
1230 180 43.75 44.375 0.63
1300 210 43.0 43.75 0.75
1330 240 43.0 43.75 0.75
Boring/Depth
(inches)
P-2/49.0
Soil:
Qop
Case III
Time Time
Change
(minutes)
Water Level
(inches)
Final Water
Level
(inches)
Water Level
Change
(inches)
Percolation Rate
Inches/
Hour
Inches
/
Minut
e
0932 Initial 41.0 N/A N/A
1002 30 41.0 42.5 1.50
1032 60 41.0 42.4 1.40
1102 90 41.0 42.4375 1.44
1132 120 41.0 42.1875 1.19
1202 150 41.0 41.75 0.75
1232 180 41.75 42.31 0.56
1302 210 41.0 41.60 0.60
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1332 240 41.60 42.2875 0.69 1.38 0.023
Boring/Depth
(inches)
P-3/51.0
Soil:
Qop
Case III
Time Time
Change
(minutes)
Water Level
(inches)
Final Water
Level
(inches)
Water Level
Change
(inches)
Percolation Rate
Inches/
Hour
Inches
/
Minut
e
0934 Initial 39.0 N/A N/A
2.5
0.042
1004 30 39.0 40.9375 1.94
1034 60 39.0 40.625 1.63
1104 90 39.0 40.5 1.50
1134 120 39.0 40.5 1.50
1204 150 39.0 40.375 1.38
1234 180 39.0 40.375 1.38
1304 210 39.0 40.1875 1.19
1334 240 39.0 40.25 1.25
Boring/Depth
(inches)
P-4/50.0
Soil:
Qop
Case III
Time Time
Change
(minutes)
Water Level
(inches)
Final Water
Level
(inches)
Water Level
Change
(inches)
Percolation Rate
Inches/
Hour
Inches
/
Minut
e
0936 Initial 42.0 N/A N/A
0.125
0.0021
1006 30 42.0 42.25 0.25
1036 60 42.25 42.50 0.25
1106 90 42.50 42.75 0.25
1136 120 42.75 43.00 0.25
1206 150 42.0 42.0625 0.0625
1236 180 42.625 42.125 0.0625
1306 210 42.125 42.1875 0.0625
1336 240 42.1875 42.25 0.0625
NOTES Qop = Quaternary Old Paralic Deposits.
Water level was measured from a fixed point at the top of the hole.
The test holes had a diameter six inches.
Weather was overcast and mild during the percolation testing.
3.3.1 Calculated Infiltration Rates
As per the County of San Diego BMP design documents (February 2016) infiltration rates
are to be evaluated through the Porchet Method. CTE utilized the Porchet Method through
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guidance of the County of Riverside (2011). The intent of the infiltration rate is to take into
account bias inherent in percolation test bore hole sidewall infiltration, which would not
occur at a constructed basin bottom where such sidewalls are not present.
The infiltration rate (It) is derived by the equation:
It= {(change H 60 r) / [change t(r+2Hav)]}
Where:
Change t=time interval
Df=final depth to water
r=test hole radius
change t=60 minutes
Do=initial depth to water
Dt=total depth of test hole
Ho=Dt – Do is initial height of water at selected time interval
Hf=Dt-Df- is the final height of water at the selected time interval
Change H=is the change in height over the time interval
Hav=(Ho+Hf) / 2 is the average head height over the time interval
Given the measurement values of Table 1.0, the calculated infiltration rates without a Factor of
Safety applied are as follows.
P-1
(units in inches)
Df=43.75
Do=43.0
Dt=51.0
r=3
change t=30 minutes
Calculated Infiltration Rate=0.2466 inches/hour
P-2
(units in inches)
Df=42.2875
Do=41.60
Dt=49.0
r=3
change t=30 minutes
Calculated Infiltration Rate=0.2411 inches/hour
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P-3
(units in inches)
Df=40.25
Do=39.0
Dt=51.0
r=3
change t=30 minutes
Calculated Infiltration Rate=0.2913 inches/hour
P-4
(units in inches)
Df=42.2875
Do=41.60
Dt=49.0
r=3
change t=30 minutes
Calculated Infiltration Rate=0.020 inches/hour
3.3.2 Calculated Infiltration Rates
Infiltration rates have been calculated utilizing the factor of safety (FOS) of 2 in the following Table
1.1. The project stormwater or basin designer may modify the factor of safety based on their
independent evaluation. The infiltration feasibility information is also presented on the attached
C.4-1 Worksheet.
TABLE 3.3.2
RESULTS OF PERCOLATION TESTING WITH FACTOR OF SAFETY APPLIED
Test Location Percolation Rate
(inches/minute)
Infiltration Rate
(inches per hour)
Infiltration Rate with FOS of
2 Applied (inches per hour)
P-1 0.025 0.25 0.12
P-2 0.023 0.24 0.12
P-3 0.042 0.29 0.15
P-4 0.0021 0.020 0.010
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Based on the calculated rates and other site factors, portions of the site meet minimum
County requirements for partial infiltration. An area that could be considered for partial
Infiltration design options is presented on Figure 2.
4.0 GEOLOGY
4.1 General Setting
Carlsbad is located within the Peninsular Ranges physiographic province that is characterized by
northwest-trending mountain ranges, intervening valleys, and predominantly northwest trending
regional faults. The greater San Diego Region can be further subdivided into the coastal plain area,
a central mountain–valley area and the eastern mountain valley area. The project site is located
within the coastal plain area that is characterized by Cretaceous, Tertiary, and Quaternary
sedimentary deposits that onlap an eroded basement surface consisting of Jurassic and Cretaceous
crystalline rocks.
4.2 Geologic Conditions
Based on the regional geologic map prepared by Kennedy and Tan (2007), the near surface geologic
unit underlying the site consists of Quaternary Old Paralic Deposits, Unit 6-7. However, based on
the site explorations, Residual Soil was observed overlying the Quaternary Old Paralic Deposits.
Descriptions of the geologic and soil units encountered are presented below.
4.2.1 Residual Soil
Where observed, the Residual Soil generally consists of loose to medium dense, dark reddish
brown, silty to clayey fine grained sand. This unit is relatively thin and blankets the
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underlying Old Paralic Deposits, and is not considered suitable for support of proposed
structural improvements or compacted fill without first processing as indicated herein.
4.2.2 Quaternary Old Paralic Deposits (Qop)
Quaternary Old Paralic Deposits were found to be the underlying geologic unit at the site.
Where observed, these materials generally consist of medium dense to dense, reddish brown
silty to clayey fine grained sandstone. These materials are considered suitable for support of
proposed improvements and compacted fill as indicated herein.
4.3 Groundwater Conditions
During the recent investigation, likely perched subsurface water was encountered at a depth of
approximately 11 feet below existing grades. Based on site conditions and recent findings, the
potential for relatively shallow subsurface water exists at the site, which could seasonally impact
deeper site excavations and earthwork during project construction. This groundwater may also
impact the retention basin feasibility. However, a permanent shallow static groundwater table is not
generally anticipated to be present at the subject site. Proper site drainage is to be designed,
installed, and maintained as per the recommendations of the project civil engineer of record.
4.4 Geologic Hazards
Geologic hazards that were considered to have potential impacts to site development were evaluated
based on field observations, literature review, and laboratory test results. It appears that the geologic
hazards at the site are primarily limited to those caused by shaking from earthquake-generated
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ground motions. The following paragraphs discuss the geologic hazards considered and their
potential risk to the site.
4.4.1 Surface Fault Rupture
Based on the site reconnaissance and review of referenced literature, the site is not within a
State of California-designated Alquist-Priolo Earthquake Fault Studies Zone or Local
Special Studies Zone and no known active fault traces underlie, or project toward, the site.
According to the California Division of Mines and Geology, a fault is active if it displays
evidence of activity in the last 11,000 years (Hart and Bryant, revised 2007). Therefore, the
potential for surface rupture from displacement or fault movement beneath the proposed
improvements is considered to be low.
4.4.2 Local and Regional Faulting
The California Geological Survey (CGS) and the United States Geological Survey (USGS)
broadly group faults as “Class A” or “Class B” (Cao, 2003; Frankel et al., 2002). Class A
faults are generally identified based upon relatively well-defined paleoseismic activity, and a
fault-slip rate of more than 5 millimeters per year (mm/yr). In contrast, Class B faults have
comparatively less defined paleoseismic activity and are considered to have a fault-slip rate
less than 5 mm/yr. The nearest known Class B fault is the Newport-Inglewood Fault, which
is approximately 8.5 kilometers west of the site (Blake, T.F., 2000). The nearest known
Class A fault is the Temecula segment of the Elsinore Fault, which is located approximately
38.6 kilometers east of the site.
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The site could be subjected to significant shaking in the event of a major earthquake on any
of the faults noted above or other faults in the southern California or northern Baja California
area.
4.4.3 Liquefaction and Seismic Settlement Evaluation
Liquefaction occurs when saturated fine-grained sands or silts lose their physical strengths
during earthquake-induced shaking and behave like a liquid. This is due to loss of
point-to-point grain contact and transfer of normal stress to the pore water. Liquefaction
potential varies with water level, soil type, material gradation, relative density, and probable
intensity and duration of ground shaking. Seismic settlement can occur with or without
liquefaction; it results from densification of loose soils.
The site is underlain at shallow depths by medium dense to dense Quaternary Old Paralic
Deposits. In addition, loose surficial soils within proposed improvement areas are to be
overexcavated and compacted as engineered fill as recommended herein. Therefore, the
potential for liquefaction or significant seismic settlement at the site is considered to be low.
4.4.4 Tsunamis and Seiche Evaluation
According to State of California Emergency Management Agency mapping, the site is not
located within a tsunami inundation zone based on distance from the coastline and elevation
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above sea level. Damage resulting from oscillatory waves (seiches) is considered unlikely
due to the absence of nearby confined bodies of water.
4.4.5 Landsliding
According to mapping by Tan (1995), the site is considered only “Marginally Susceptible” to
landsliding and no landslides are mapped in the site area. Furthermore, landslides or similar
associated features were not observed during the recent field exploration. Therefore,
landsliding is not considered to be a significant geologic hazard at the site.
4.4.6 Compressible and Expansive Soils
The Residual Soil across the surface of the site is considered to be potentially compressible.
Therefore, these soils should be overexcavated, processed, and placed as a properly
compacted fill as recommended herein. Based on the field data, site observations, and
laboratory results, the underlying Old Paralic Deposits are not considered to be subject to
significant compressibility under the anticipated loads.
Based on observation and laboratory test results, soils at the site are generally anticipated to
exhibit Very Low expansion potential (Expansion Index of 20 or less). Therefore, expansive
soils are not anticipated to present significant adverse impacts to site development.
Additional evaluation of near-surface soils can and should be performed based on field
observations during grading activities.
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4.4.7 Corrosive Soils
Chemical testing was performed to evaluate the potential effects that site soils may have on
concrete foundations and various types of buried metallic utilities. Soil environments
detrimental to concrete generally have elevated levels of soluble sulfates and/or pH levels
less than 5.5. According to American Concrete Institute (ACI) Table 318 4.3.1, specific
guidelines have been provided for concrete where concentrations of soluble sulfate (SO4) in
soil exceed 0.1 percent by weight. These guidelines include low water: cement ratios,
increased compressive strength, and specific cement type requirements.
Based on the results of the Sulfate and pH testing performed, onsite soils are anticipated to
generally have a negligible corrosion potential to Portland cement concrete improvements.
A minimum resistivity value less than approximately 5,000 ohm-cm, and/or soluble chloride
levels in excess of 200 ppm generally indicate a corrosive environment to buried metallic
utilities and untreated conduits. Based on the obtained resistivity value of 15,700 ohm-cm
and soluble chloride level of 13.4 ppm, onsite soils are anticipated to have a low corrosion
potential for buried uncoated/unprotected metallic conduits. Nevertheless, at a minimum,
the use of buried plastic piping or conduits could be beneficial, where feasible.
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The results of the chemical tests performed are presented in the attached Appendix C.
However, CTE does not practice corrosion engineering. Therefore, a corrosion engineer or
other qualified consultant could be contacted if site specific corrosivity issues are of concern.
5.0 CONCLUSIONS AND RECOMMENDATIONS
5.1 General
CTE concludes that the proposed improvements at the site are feasible from a geotechnical
standpoint, provided the recommendations in this report are incorporated into the design and
construction of the project. Recommendations for the proposed earthwork and improvements are
included in the following sections and Appendix D. However, recommendations in the text of this
report supersede those presented in Appendix D should variations exist. These recommendations
should either be confirmed as appropriate and/or updated during or following rough grading at the
site.
5.2 Site Preparation
Prior to grading, the site should be cleared of any existing building materials or improvements that
are not to remain. Objectionable materials, such as construction debris and vegetation, not suitable
for structural backfill should be properly disposed of offsite. In the area of the proposed structures
(and a minimum five feet laterally beyond, where feasible), existing soils should be uniformly
excavated to a minimum depth of 18 inches below the bottom of the deepest proposed foundations,
or to the depth of suitable material, whichever depth is greatest. Localized areas of loose and
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potentially compressible material could require overexcavation to deeper elevations, based on
conditions encountered during grading. Overexcavations should extend at least five feet laterally
beyond the limits of the proposed building, where feasible.
Excavations in proposed pavement, flatwork, or other minor improvement areas should be conducted
to a minimum depth of two feet below proposed or existing grades, or to suitable underlying
materials, whichever depth is shallowest.
A CTE geotechnical representative should observe the exposed ground surface at the overexcavation
bottoms to evaluate the exposed conditions. The exposed subgrades to receive fill should be proof-
rolled or scarified a minimum of nine inches, moisture conditioned to a minimum of two percent
above optimum, and properly compacted prior to additional fill placement.
5.3 Site Excavation
Generally, excavation of site materials may be accomplished with heavy-duty construction
equipment under normal conditions. However, the Old Paralic Deposits may become increasingly
difficult to excavate with depth. Materials also appear to be, at least locally, very granular and could
be very sensitive to caving and/or erosion.
5.4 Fill Placement and Compaction
Granular fill and backfill should be compacted to a minimum relative compaction of 90 percent at a
moisture content of at least two percent above optimum, as evaluated by ASTM D 1557. The
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optimum lift thickness for fill soil will depend on the type of compaction equipment used.
Generally, backfill should be placed in uniform, horizontal lifts not exceeding eight inches in loose
thickness. Fill placement and compaction should be conducted in conformance with local
ordinances.
5.5 Fill Materials
Properly moisture-conditioned very low expansion potential soils derived from the on-site
excavations are considered suitable for reuse on the site as compacted fill. If used, these materials
should be screened of organics and materials generally greater than three inches in maximum
dimension. Irreducible materials greater than three inches in maximum dimension should generally
not be used in shallow fills (within three feet of proposed grades). In utility trenches, adequate
bedding should surround pipes.
Imported fill beneath structures, flatwork, and pavements should have an Expansion Index of 30 or
less (ASTM D 4829). Imported fill soils for use in structural or slope areas should be evaluated by
the geotechnical engineer before being imported to the site.
Minor retaining wall backfill (if necessary) located within a 45-degree wedge extending up from the
heel of the wall should consist of soil having an Expansion Index of 20 or less (ASTM D 4829) with
less than 30 percent passing the No. 200 sieve. The upper 12 to 18 inches of wall backfill could
consist of lower permeability soils, in order to reduce surface water infiltration behind walls. The
project structural engineer and/or architect should detail proper wall backdrains, including gravel
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drain zones, fills, filter fabric, and perforated drain pipes. However, a conceptual wall backdrain
detail, which may be suitable for use at the site, is provided as Figure 4.
5.6 Temporary Construction Slopes
The following recommended slopes should be relatively stable against deep-seated failure, but may
experience localized sloughing. On-site soils are considered Type B and Type C soils with
recommended slope ratios as set forth in Table 5.6. However, due to the at least locally granular and
erodible nature of the onsite soils, maximum 1.5:1 temporary slopes are anticipated to be more
reliable, and vertical excavations may not remain standing, even at shallow or minor heights.
TABLE 5.6
RECOMMENDED TEMPORARY SLOPE RATIOS
SOIL TYPE SLOPE RATIO
(Horizontal: vertical) MAXIMUM HEIGHT
B (Old Paralic Deposits) 1:1 (OR FLATTER) 10 Feet
C (Residual Soil) 1.5:1 (OR FLATTER) 10 Feet
Actual field conditions and soil type designations must be verified by a "competent person" while
excavations exist, according to Cal-OSHA regulations. In addition, the above sloping
recommendations do not allow for surcharge loading at the top of slopes by vehicular traffic,
equipment or materials. Appropriate surcharge setbacks must be maintained from the top of all
unshored slopes.
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5.7 Foundations and Slab Recommendations
The following recommendations are for preliminary design purposes only. These recommendations
should be reviewed after completion of earthwork to document that conditions exposed are as
anticipated, and that the recommended structure design parameters are appropriate.
5.7.1 Foundations
Following the preparatory grading recommended herein, continuous and isolated spread
footings are anticipated to be suitable for use at this site. It is anticipated that building
footings will be founded entirely in properly compacted fill with very low expansion
potential.
Foundation dimensions and reinforcement should be based on an allowable bearing value of
2,500 pounds per square foot for footings founded entirely upon properly placed compacted
fill materials embedded a minimum of 18 inches below the lowest adjacent subgrade
elevation. If utilized, continuous footings should be at least 18 inches wide; isolated footings
should be at least 24 inches in least dimension. The above bearing values may also be
increased by one third for short duration loading which includes the effects of wind or
seismic forces.
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An uncorrected 150-pci subgrade modulus is considered suitable for elastic design of
foundations as embedded and/or detailed herein.
Minimum reinforcement for continuous footings should consist of four No. 4 reinforcing
bars; two placed near the top and two placed near the bottom or as per the project structural
engineer. The structural engineer should design isolated footing reinforcement. Footing
excavations should generally be maintained above optimum moisture content until concrete
placement.
5.7.2 Foundation Settlement
The maximum total settlement is expected to be on the order of one inch and the maximum
differential settlement is expected to be on the order of 1/2 inch over a distance of
approximately 40 feet. Due to the absence of a shallow static or sustained groundwater table
and the generally dense nature of underlying materials, dynamic settlement is not expected to
adversely affect the proposed improvements.
5.7.3 Foundation Setback
Footings for structures should be designed such that the horizontal distance from the face of
adjacent slopes to the outer edge of the footing is at least 10 feet. In addition, footings
should bear beneath a 1:1 plane extended up from the nearest bottom edge of adjacent
trenches and/or excavations. Deepening of affected footings may be a suitable means of
attaining the prescribed setbacks.
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5.7.4 Interior Concrete Slabs
Lightly loaded concrete slabs should be a minimum of 4.5 inches in thickness. Minimum
slab reinforcement should consist of #3 reinforcing bars placed on maximum 16-inch
centers, each way, at above mid-slab height, but with proper concrete cover. Subgrade
materials should generally be maintained at above optimum moisture content until slab
underlayment and concrete are placed.
Slabs subjected to heavier loads may require thicker slab sections and/or increased
reinforcement. A 140-pci subgrade modulus is considered suitable for elastic design of
minimally embedded improvements such as slabs-on-grade.
In moisture-sensitive floor areas, a suitable vapor retarder of at least 15-mil thickness (with
all laps or penetrations sealed or taped) overlying a four-inch layer of consolidated crushed
aggregate or gravel (with SE of 30 or more) should be installed, as per the 2013 CBC/Green
Building Code. An optional maximum two-inch layer of similar material may be placed
above the vapor retarder to help protect the membrane during steel and concrete placement.
This recommended protection is generally considered typical in the industry. If proposed
floor areas or coverings are considered especially sensitive to moisture emissions, additional
recommendations from a specialty consultant could be obtained. CTE is not an expert at
preventing moisture penetration through slabs. A qualified architect or other experienced
professional should be contacted if moisture penetration is a more significant concern.
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5.8 Seismic Design Criteria
The seismic ground motion values listed in the table below were derived in accordance with the
ASCE 7-10 Standard and 2016 CBC. This was accomplished by establishing the Site Class based on
the soil properties at the site, and then calculating the site coefficients and parameters using the
United States Geological Survey Seismic Design Maps application using the site coordinates of
33.1639 degrees latitude and -117.3448 degrees longitude. These values are intended for the design
of structures to resist the effects of earthquake ground motions.
TABLE 5.8
SEISMIC GROUND MOTION VALUES
PARAMETER VALUE CBC REFERENCE (2013)
Site Class D ASCE 7, Chapter 20
Mapped Spectral Response
Acceleration Parameter, SS 1.145 Figure 1613.3.1 (1)
Mapped Spectral Response
Acceleration Parameter, S1 0.439 Figure 1613.3.1 (2)
Seismic Coefficient, Fa 1.042 Table 1613.3.3 (1)
Seismic Coefficient, Fv 1.561 Table 1613.3.3 (2)
MCE Spectral Response
Acceleration Parameter, SMS 1.193 Section 1613.3.3
MCE Spectral Response
Acceleration Parameter, SM1 0.685 Section 1613.3.3
Design Spectral Response
Acceleration, Parameter SDS 0.795 Section 1613.3.4
Design Spectral Response
Acceleration, Parameter SD1 0.457 Section 1613.3.4
Peak Ground Acceleration PGAM 0.474 ASCE 7, Section 11.8.3
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5.9 Lateral Resistance and Earth Pressures
Lateral loads acting against retaining walls may be resisted by friction between the footings and the
supporting compacted fill soil and/or Old Paralic Deposits or passive pressure acting against
structures. If frictional resistance is used, an allowable coefficient of friction of 0.30 (total frictional
resistance equals the coefficient of friction multiplied by the dead load) is recommended for concrete
cast directly against competent soils. A design passive resistance value of 250 pounds per square
foot per foot of depth (with a maximum value of 2,000 pounds per square foot) may be used. The
allowable lateral resistance can be taken as the sum of the frictional resistance and the passive
resistance, provided the passive resistance does not exceed two-thirds of the total allowable
resistance.
If proposed, retaining walls up to approximately eight feet high and backfilled using granular soils
may be designed using the equivalent fluid weights given below.
TABLE 5.10
EQUIVALENT FLUID UNIT WEIGHTS
(pounds per cubic foot)
WALL TYPE LEVEL BACKFILL
SLOPE BACKFILL
2:1 (HORIZONTAL:
VERTICAL)
CANTILEVER WALL
(YIELDING) 30 48
RESTRAINED WALL 60 75
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Lateral pressures on cantilever retaining walls (yielding walls) due to earthquake motions may be
calculated based on work by Seed and Whitman (1970). The total lateral thrust against a properly
drained and backfilled cantilever retaining wall above the groundwater level can be expressed as:
PAE = PA + ΔPAE
For non-yielding (or “restrained”) walls, the total lateral thrust may be similarly calculated
based on work by Wood (1973):
PKE = PK + ΔPKE
Where PA = Static Active Thrust (determined using Table 5.9)
PK = Static Restrained Wall Thrust (determined using Table 5.9)
ΔPAE = Dynamic Active Thrust Increment = (3/8) kh γH2 ΔPKE = Dynamic Restrained Thrust Increment = kh γH2
kh = 2/3 Peak Ground Acceleration = 2/3 (PGAM)
H = Total Height of the Wall
γ = Total Unit Weight of Soil ≈ 135 pounds per cubic foot
The increment of dynamic thrust in both cases should be distributed triangularly with a line of action
located at H/3 above the bottom of the wall (SEAOC, 2013).
These values assume non-expansive backfill and free-draining conditions. Measures should be taken
to prevent moisture buildup behind all retaining walls. Drainage measures should include free-
draining backfill materials and sloped, perforated drains. These drains should discharge to an
appropriate off-site location. A general or conceptual detail for Retaining Wall Drainage, which
may be appropriate for the subject site based on the review of the project structural engineer and/or
architect, is attached as Figure 4. Waterproofing should be as specified by the project architect or
the waterproofing specialty consultant.
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5.10 Exterior Flatwork
To reduce the potential for cracking in exterior non-traffic flatwork areas caused by minor
movement of subgrade soils and typical concrete shrinkage, it is recommended that such flatwork
measure a minimum 4.5 inches thick and be installed with crack-control joints at appropriate spacing
as designed by the project architect. Additionally, it is recommended that flatwork be installed with
at least No. 3 reinforcing bars on maximum 18-inch centers, each way, at above mid-height of slab
but with proper concrete cover, or other reinforcement per the project consultants. Doweling of
flatwork joints at critical pathways or similar could also be beneficial in resisting minor subgrade
movements.
Subgrades should be prepared according to the earthwork recommendations previously given, before
placing concrete. Positive drainage should be established and maintained next to all flatwork.
Subgrade materials shall be maintained at, or be elevated to, above optimum moisture content prior
to concrete placement.
5.11 Pavements
Pavement sections provided are based on estimated Resistance “R”-Value results, traffic indices, and
the assumption that the upper foot of compacted fill subgrade and overlying aggregate base materials
are properly compacted to a minimum 95% relative compaction at a minimum of two percent above
optimum moisture content (as per ASTM D 1557). Beneath proposed pavement areas, loose, clayey,
or otherwise unsuitable soils are to be removed to the depth of competent underlying material as
recommended in Section 5.2. R-Value of subgrade material should be verified during grading and
pavement sections may be modified as necessary.
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TABLE 5.12
RECOMMENDED AC OR PCC PAVEMENT SECTION THICKNESSES
Traffic Area
Assumed
Traffic Index
Preliminary
Subgrade
“R”-Value
Asphalt Pavements
Portland Cement
Concrete
Pavements On
Subgrade
(INCHES)
AC
Thickness
(INCHES)
CalTrans Class II or
Crushed Miscellaneous
Aggregate Base
Thickness
(INCHES)
Light Auto
Parking & Drive
Areas
4.5
30
3.0
5.0
6.0
Heavy Quantity
Drive or Impact
Areas
5.5
30
3.0
9.0
7.0
Asphalt paved areas should be designed, constructed, and maintained in accordance with, for
example, the recommendations of the Asphalt Institute, or other widely recognized authority.
Concrete paved areas should be designed and constructed in accordance with the recommendations
of the American Concrete Institute or other widely recognized authority, particularly with regard to
thickened edges, joints, and drainage. The Standard Specifications for Public Works construction
(“Greenbook”) or Caltrans Standard Specifications may be referenced for pavement materials
specifications.
5.12 Drainage
Surface runoff should be collected and directed away from improvements by means of appropriate
erosion-reducing devices, and positive drainage should be established around proposed
improvements. Positive drainage should be directed away from improvements and slope areas at a
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minimum gradient of two percent for a distance of at least five feet. However, the project civil
engineer should evaluate the on-site drainage and make necessary provisions to keep surface water
from affecting the site.
Generally, CTE recommends against allowing water to infiltrate building pads or adjacent to slopes
and improvements. However, it is understood that some agencies are encouraging the use of storm-
water cleansing devices. Therefore, if storm water cleansing devices must be used, it is generally
recommended that they be underlain by an impervious barrier and that the infiltrate be collected via
subsurface piping and discharged off site. If infiltration must occur, water should infiltrate as far
away from structural improvements as feasible. Additionally, any reconstructed slopes descending
from infiltration basins should be equipped with subdrains to collect and discharge accumulated
subsurface water (Appendix D contains general or typical details for internal fill slope drainage).
Infiltration/percolation design and associated information elsewhere in this report should also be
reviewed in its entirely.
5.13 Slopes
Based on observed conditions and anticipated soil strength characteristics, cut and fill slopes, if
proposed at the site, should be constructed at ratios of 2:1 (horizontal: vertical) or flatter. These fill
slope inclinations should exhibit factors of safety greater than 1.5.
Although properly constructed slopes on this site should be grossly stable, the soils will be
somewhat erodible. Therefore, runoff water should not be permitted to drain over the edges of
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slopes unless that water is confined to properly designed and constructed drainage facilities.
Erosion-resistant vegetation should be maintained on the face of all slopes. Typically, soils along
the top portion of a fill slope face will creep laterally. CTE recommends against building distress-
sensitive hardscape improvements within five feet of slope crests.
5.14 Plan Review
CTE should be authorized to review the project grading and foundation plans prior to
commencement of earthwork to identify potential conflicts with the intent of the geotechnical
recommendations.
5.15 Construction Observation
The recommendations provided in this report are based on preliminary design information for the
proposed construction and the subsurface conditions observed in the explorations performed. The
interpolated subsurface conditions should be checked in the field during construction to verify that
conditions are as anticipated. Foundation recommendations may be revised upon completion of
grading and as-built laboratory test results.
Recommendations provided in this report are based on the understanding and assumption that CTE
will provide the observation and testing services for the project. All earthwork should be observed
and tested to verify that grading activities have been performed according to the recommendations
contained within this report. CTE should evaluate all footing trenches before reinforcing steel
placement.
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6.0 LIMITATIONS OF INVESTIGATION
The field evaluation, laboratory testing, and geotechnical analysis presented in this report have been
conducted according to current engineering practice and the standard of care exercised by reputable
geotechnical consultants performing similar tasks in this area. No other warranty, expressed or
implied, is made regarding the conclusions, recommendations and opinions expressed in this report.
Variations may exist and conditions not observed or described in this report may be encountered
during construction.
The recommendations presented herein have been developed in order to help reduce the potential
adverse effects of soils movement. However, even with the design and construction precautions
provided, some post-construction movement and associated distress should be anticipated.
The findings of this report are valid as of the present date. 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.
CTE’s conclusions and recommendations are based on an analysis of the observed conditions. If
conditions different from those described in this report are encountered, this office should be notified
and additional recommendations, if required, will be provided.
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The opportunity to be of service on this project is appreciated. If you have any questions regarding
this report, please do not hesitate to contact the undersigned.
Respectfully submitted,
CONSTRUCTION TESTING & ENGINEERING, INC.
Dan T. Math, GE #2665 Jay F. Lynch, CEG #1890
Principal Engineer Principal Engineering Geologist
Aaron J. Beeby, CEG #2603
Project Geologist
AJB/JFL/DTM:nri
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B-4B-3P-4B-1QopP-1QopB-2P-3P-2P-4LEGENDQuaternary Old Paralic DepositsQopB-4 Approximate Boring Location Approximate Percolation Test LocationPartial Infiltration Area Indicated for BMP Design OptionsC> ~ i:::, N Cl) L.. :::, C> 5-c., I'} v U) I'} I 0 ;;, 1/) ~ +' 0 -~ 0 $ L.. J, L.. Cl) > L.. Cl) ~ 1/) I 0 1/) ~ / ----:: tr 30' 0 15' 30' Cl~ Construction Testing & Engineering, Inc. ~L. 1441 Montiel Rd ste 115, Escondido, CA 92026 Ph (760} 746--4955 GBOLOGIC/DPLORA.TION LOCATION IBP SCAL;: • DATE: PROPOSED TWO TRIPLEX TOWNHOIIE CONDOIIINWIIS l =30 5/17 972 AND 988 GRAND AVENUE CTE JOB NO.: FIGURE: CARLSBAD, CALIFORNIA 1O-13643G 2
APPROXIMATESITE LOCATIONLEGENDHISTORIC FAULT DISPLACEMENT (LAST 200 YEARS)HOLOCENE FAULT DISPLACEMENT (DURING PAST 11,700 YEARS)LATE QUATERNARY FAULT DISPLACMENT (DURING PAST 700,000 YEARS) QUATERNARY FAULT DISPLACEMENT (AGE UNDIFFERENTIATED)PREQUATERNARY FAULT DISPLACEMENT (OLDER THAN 1.6 MILLION YEARS)>7.06.5-6.95.5-5.95.0-5.4PERIOD1800- 1869- 1932-1868 1931 2010LAST TWO DIGITS OF M > 6.5EARTHQUAKE YEARMAGNITUDE\ \. OTES: FAULT ACTIVITY MAP OF CAID'ORNIA. 2010, CALIFORNIA GEOLOGIC DATA MAP SERIES MAP NO. 8; EPICRNTRHS or AND AREAS DAMAGED BY ~ 5 CAUFORNIA EARTHQUAKIS, 1800-1999 ADAPTED AF1'D TOPPOZAD!, BRANUII, PETRRSEN, HmSl'ORM, CRAMER, AND REICIILR, 2000, CDIIG MAP Silffl 4-9 REF!RINCE FOR ADDfflONAL EXPLANATION; IIODIPIIID WITH CISN AND USGS SEISIIIC KAPS ~ CTEJNC ~ --·······?-M E Construction Testing & Engineering, Inc. 1441 Montiel Rd ste 115, Escondido, CA 92026 Ph (760) 746-4955 12 0 6 12 ~---I __ I 1 inch = 12 mi. 0 0 0 0 X I ..--. C • • 0 0 0 0 J.
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BY FILTER FABRIC (MIRAFI
14O N, OR EQUIVALENT)
-OR-
PREFABRICATED
DRAINAGE BOARD
RETAINING WALL
FINISH GRADE
4" DIA. PERFORATED PVC
PIPE (SCHEDULE 40 OR
EQUIVALENT). MINIMUM
1% GRADIENT TO SUITABLE
OUTLET
WALL FOOTING
12" TO 18" OF LOWER
PERMEABILITY NATIVE
MATERIAL COMPACTED TO 90%
RELATIVE COMPACTION
SELECT GRANULAR WALL
BACKFILL COMPACTED
TO 90% RELATIVE COMPACTION
WATERPROOFING TO BE
SPECIFIED BY ARCHITECT
CTE JOB NO:
DATE:FIGURE:
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APPENDIX A
REFERENCES
REFERENCES
1. American Society for Civil Engineers, 2010, “Minimum Design Loads for Buildings and
Other Structures,” ASCE/SEI 7-10.
2. ASTM, 2002, “Test Method for Laboratory Compaction Characteristics of Soil Using
Modified Effort,” Volume 04.08
3. Blake, T.F., 2000, “EQFAULT,” Version 3.00b, Thomas F. Blake Computer Services and
Software.
4. California Building Code, 2013, “California Code of Regulations, Title 24, Part 2, Volume 2
of 2,” California Building Standards Commission, published by ICBO, June.
5. California Division of Mines and Geology, CD 2000-003 “Digital Images of Official Maps
of Alquist-Priolo Earthquake Fault Zones of California, Southern Region,” compiled by
Martin and Ross.
6. California Emergency Management Agency/California Geological Survey, “Tsunami
Inundation Maps for Emergency Planning.
7. Frankel, A.D., Petersen, M.D., Mueller, C.S., Haller, K.M., Wheeler, R.L., Leyendecker,
E.V., Wesson, R. L., Harmsen, S.C., Cramer, C.H., Perkins, D.M., Rukstales,K.S.,2002,
Documentation for the 2002 update of the National Seismic Hazard Maps: U.S. Geological
Survey Open-File Report 2002-420, 39p
8. Hart, Earl W., Revised 2007, “Fault-Rupture Hazard Zones in California, Alquist Priolo,
Special Studies Zones Act of 1972,” California Division of Mines and Geology, Special
Publication 42.
9. Jennings, Charles W., 1994, “Fault Activity Map of California and Adjacent Areas” with
Locations and Ages of Recent Volcanic Eruptions.
10. Kennedy, M.P. and Tan, S.S., 2007, “Geologic Map of the Oceanside 30’ x 60’ Quadrangle,
California”, California Geological Survey, Map No. 2, Plate 1 of 2.
11. Reichle, M., Bodin, P., and Brune, J., 1985, The June 1985 San Diego Bay Earthquake
swarm [abs.]: EOS, v. 66, no. 46, p.952.
12. SEAOC, Blue Book-Seismic Design Recommendations, “Seismically Induced Lateral Earth
Pressures on Retaining Structures and Basement Walls,” Article 09.10.010, October 2013.
13. Seed, H.B., and R.V. Whitman, 1970, “Design of Earth Retaining Structures for Dynamic
Loads,” in Proceedings, ASCE Specialty Conference on Lateral Stresses in the Ground and
Design of Earth-Retaining Structures, pp. 103-147, Ithaca, New York: Cornell University.
14. Simons, R.S., 1979, Instrumental Seismicity of the San Diego area, 1934-1978, in Abbott,
P.L. and Elliott, W.J., eds., Earthquakes and other perils, San Diego region: San Diego
Association of Geologists, prepared for Geological Society of America field trip, November
1979, p.101-105.
15. Tan, S. S., and Giffen, D. G., 1995, “Landslide Hazards in the Northern Part of the San
Diego Metropolitan Area, San Diego County, California: Oceanside and San Luis Rey
Quadrangles, Landslide Hazard Identification Map No. 35”, California Department of
Conservation, Division of Mines and Geology, Open-File Report 95-04, State of California,
Division of Mines and Geology, Sacramento, California.
16. Wood, J.H. 1973, Earthquake-Induced Soil Pressures on Structures, Report EERL 73-05.
Pasadena: California Institute of Technology.
APPENDIX B
EXPLORATION LOGS
DEFINITION OF TERMS
PRIMARY DIVISIONS SYMBOLS SECONDARY DIVISIONS
WELL GRADED GRAVELS, GRAVEL-SAND MIXTURES
LITTLE OR NO FINES
POORLY GRADED GRAVELS OR GRAVEL SAND MIXTURES,
LITTLE OF NO FINES
SILTY GRAVELS, GRAVEL-SAND-SILT MIXTURES,
NON-PLASTIC FINES
CLAYEY GRAVELS, GRAVEL-SAND-CLAY MIXTURES,
PLASTIC FINES
WELL GRADED SANDS, GRAVELLY SANDS, LITTLE OR NO
FINES
POORLY GRADED SANDS, GRAVELLY SANDS, LITTLE OR
NO FINES
SILTY SANDS, SAND-SILT MIXTURES, NON-PLASTIC FINES
CLAYEY SANDS, SAND-CLAY MIXTURES, PLASTIC FINES
INORGANIC SILTS, VERY FINE SANDS, ROCK FLOUR, SILTY
OR CLAYEY FINE SANDS, SLIGHTLY PLASTIC CLAYEY SILTS
INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY,
GRAVELLY, SANDY, SILTS OR LEAN CLAYS
ORGANIC SILTS AND ORGANIC CLAYS OF LOW PLASTICITY
INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE
SANDY OR SILTY SOILS, ELASTIC SILTS
INORGANIC CLAYS OF HIGH PLASTICITY, FAT CLAYS
ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY,
ORGANIC SILTY CLAYS
PEAT AND OTHER HIGHLY ORGANIC SOILS
GRAIN SIZES
GRAVEL SAND
COARSE FINE COARSE MEDIUM FINE
12" 3" 3/4" 4 10 40 200
CLEAR SQUARE SIEVE OPENING U.S. STANDARD SIEVE SIZE
ADDITIONAL TESTS
(OTHER THAN TEST PIT AND BORING LOG COLUMN HEADINGS)
MAX- Maximum Dry Density PM- Permeability PP- Pocket Penetrometer
GS- Grain Size Distribution SG- Specific Gravity WA- Wash Analysis
SE- Sand Equivalent HA- Hydrometer Analysis DS- Direct Shear
EI- Expansion Index AL- Atterberg Limits UC- Unconfined Compression
CHM- Sulfate and Chloride RV- R-Value MD- Moisture/Density
Content , pH, Resistivity CN- Consolidation M- Moisture
COR - Corrosivity CP- Collapse Potential SC- Swell Compression
SD- Sample Disturbed HC- Hydrocollapse OI- Organic Impurities
REM- Remolded
FIGURE: BL1
GW
SILTS AND CLAYS
LIQUID LIMIT ISLESS THAN 50
SILTS AND CLAYS
LIQUID LIMIT IS
GREATER THAN 50
SANDS
MORE THAN
HALF OF
COARSE
FRACTION IS
SMALLER THAN
NO. 4 SIEVE
GRAVELS
MORE THAN
HALF OF
COARSE
FRACTION IS
LARGER THAN
NO. 4 SIEVE
CLEAN
GRAVELS
< 5% FINES
GRAVELS WITH FINES
CLEAN
SANDS
< 5% FINES
SANDS
WITH FINESCOARSE GRAINED SOILSMORE THAN HALF OF MATERIAL IS LARGER THAN NO. 200 SIEVE SIZEGP
GM
GC
SW
SP
SM
SC
ML
CL
OL
MH
CH
OH
PTFINE GRAINED SOILSMORE THAN HALF OF MATERIAL IS SMALLER THAN NO. 200 SIEVE SIZEHIGHLY ORGANIC SOILS
SILTS AND CLAYSCOBBLESCOBBLESBOULDERS
Construction Testing & Engineering, Inc.
1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
PROJECT:DRILLER:SHEET:of
CTE JOB NO:DRILL METHOD:DRILLING DATE:
LOGGED BY:SAMPLE METHOD:ELEVATION:Depth (Feet)Bulk SampleDriven TypeBlows/FootDry Density (pcf)Moisture (%)U.S.C.S. SymbolGraphic LogBORING LEGEND Laboratory Tests
DESCRIPTION
Block or Chunk Sample
Bulk Sample
Standard Penetration Test
Modified Split-Barrel Drive Sampler (Cal Sampler)
Thin Walled Army Corp. of Engineers Sample
Groundwater Table
Soil Type or Classification Change
???????
Formation Change [(Approximate boundaries queried (?)]
"SM"Quotes are placed around classifications where the soilsexist in situ as bedrock
FIGURE: BL2
~ Construction Testing & Engineering, Inc. C~c 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 7 46-4955
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PROJECT:EXCAVATOR:CTE JOB NO: EXCAVATION METHOD:LOGGED BY: SAMPLING METHOD: ELEVATION:Dry Density (pcf)Moisture (%)U.S.C.S. SymbolGraphic LogDepth (Feet)Bulk SampleDriven TypeLaboratory Tests SM "SM""SC"Total Depth: 12.5' (Refusal on gravel) Groundwater seepage encountered at approximately 11.9 feet FIGURE:B-1EIBORING LOG B-1DESCRIPTION5/9/2017AJB BULK ~68 FEETAJB10-13643G HAND AUGEREXCAVATION DATE:PROPOSED TRIPLEX CONDOMINIUMS051015RESIDUAL SOIL:Loose, moist, dark reddish brown, silty fine grained SAND.QUATERNARY VERY OLD PARALIC DEPOSITS:Medium dense, moist, reddish brown, silty fine grained SANDSTONE, oxidized, massive.Abundant manganese nodulesMedium dense, moist, reddish brown, clayey fine grained SANDSTONE, oxidized, massive, moderately cemented.Groundwater seepage encountered at approximately 11.9 feet~ Construction Testing & Engineering, Inc. C~c 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955 -~ - -- -- -- -- -- ---------------------------------------------------------------------------------------------------------- -- -- -- ---- -- -- -- -- -I
PROJECT:EXCAVATOR:CTE JOB NO: EXCAVATION METHOD:LOGGED BY: SAMPLING METHOD: ELEVATION:Dry Density (pcf)Moisture (%)U.S.C.S. SymbolGraphic LogDepth (Feet)Bulk SampleDriven TypeLaboratory Tests SM "SC""SM""SC"Total Depth: 12.5' (Refusal on gravel) Groundwater seepage encountered at approximately 11.6 feet FIGURE:PROPOSED TRIPLEX CONDOMINIUMS AJB10-13643G HAND AUGEREXCAVATION DATE:5/9/2017AJB BULK ~68 FEETBORING LOG B-2DESCRIPTIONGSB-2051015RESIDUAL SOIL:Loose, slightly moist, dark brown, silty fine grained SAND.QUATERNARY VERY OLD PARALIC DEPOSITS:Medium dense to dense, moist, reddish brown, clayey fine grained SANDSTONE, oxidized, massive, manganeze nodules.Medium dense, moist, light reddish brown, silty fine grained SANDSTONE, oxidized, massive, moderately cemented.Medium dense to dense, moist, reddish brown, clayey fine grained SANDSTONE, oxidized, massive.GravelGroundwater seepage encountered at approximately 11.6 feet.Medium dense, wet, gray, poorly graded medium grained SANDSTONE with gravel, friable.Construction Testing & Engineering, Inc. 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955 - -- -- -- ----------~-------------------------------------------------------------------------------------------· - -- -- -- -- -- -- -!'.,__ ____________________________________________ .... - -- -- -- -- -I
PROJECT:EXCAVATOR:CTE JOB NO: EXCAVATION METHOD:LOGGED BY: SAMPLING METHOD: ELEVATION:Dry Density (pcf)Moisture (%)U.S.C.S. SymbolGraphic LogDepth (Feet)Bulk SampleDriven TypeLaboratory Tests SM "SM"Total Depth: 5' (Refusal on gravel)No groundwater encountered FIGURE:PROPOSED TRIPLEX CONDOMINIUMS AJB10-13643G HAND AUGEREXCAVATION DATE:5/9/2017AJB BULK ~68 FEETBORING LOG B-3DESCRIPTIONGS, CHMB-3051015RESIDUAL SOIL:Loose, moist, dark brown, silty fine grained SAND.QUATERNARY VERY OLD PARALIC DEPOSITS:Medium dense, moist, reddish brown, silty fine grained SANDSTONE, oxidized, massive, manganese nodules.GravelBecomes dense with abundant manganese~ Construction Testing & Engineering, Inc. C~c 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955 -~ - -- -- -- -- -- -- -- -- -- ---- -- -- -- -- -I
PROJECT:EXCAVATOR:CTE JOB NO: EXCAVATION METHOD:LOGGED BY: SAMPLING METHOD: ELEVATION:Dry Density (pcf)Moisture (%)U.S.C.S. SymbolGraphic LogDepth (Feet)Bulk SampleDriven TypeLaboratory Tests SM "SM"Total Depth: 3' (Refusal on gravel)No groundwater encountered FIGURE:PROPOSED TRIPLEX CONDOMINIUMS AJB10-13643G HAND AUGEREXCAVATION DATE:5/9/2017AJB BULK ~68 FEETBORING LOG B-4DESCRIPTIONB-4051015RESIDUAL SOIL:Loose, moist, dark reddish brown, silty fine grained SAND with trace gravel, roots.QUATERNARY VERY OLD PARALIC DEPOSITS:Medium dense, moist, reddish brown, silty fine grained SANDSTONE with gravel, oxidized, massive.~ Construction Testing & Engineering, Inc. C~c 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955 -~ - -- -~ ... - -- -- -- -- -- -- -- ---- -- -- -- -- -I
APPENDIX C
LABORATORY METHODS AND RESULTS
APPENDIX C
LABORATORY METHODS AND RESULTS
Laboratory Testing Program
Laboratory tests were performed on representative soil samples to detect their relative engineering
properties. Tests were performed following test methods of the American Society for Testing
Materials or other accepted standards. The following presents a brief description of the various test
methods used.
Classification
Soils were classified visually according to the Unified Soil Classification System. Visual
classifications were supplemented by laboratory testing of selected samples according to ASTM
D2487. The soil classifications are shown on the Exploration Logs in Appendix B.
Particle-Size Analysis
Particle-size analyses were performed on selected representative samples according to ASTM D 422.
Expansion Index
Expansion testing was performed on selected samples of the matrix of the on-site soils according to
ASTM D 4829.
Chemical Analysis
Soil materials were collected with sterile sampling equipment and tested for Sulfate and Chloride
content, pH, Corrosivity, and Resistivity.
LABORATORY SUMMARY CTE JOB NO. 10-13643G
LOCATION EXPANSION INDEX EXPANSION
POTENTIAL
B-1 7 VERY LOW
LOCATION RESULTS
ppm
B-3 28.4
LOCATION RESULTS
ppm
B-3 13.4
LOCATION RESULTS
B-3 8.07
LOCATION RESULTS
ohms-cm
B-3 15,7000-5
(feet)
0-5
RESISTIVITY
CALIFORNIA TEST 424
DEPTH
(feet)
DEPTH
(feet)
0-5
p.H.
DEPTH
DEPTH
(feet)
0-5
CHLORIDE
SULFATE
DEPTH
(feet)
0-10
EXPANSION INDEX TEST
ASTM D 4829
Construction Testing & Engineering, Inc.
1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955
PARTICLE SIZE ANALYSISSample Designation Sample Depth (feet) Symbol Liquid Limit (%) Plasticity Index ClassificationB-20-1--SMB-30-5--SMCTE JOB NUMBER: 10-13643GFIGURE: C-101020304050607080901000.0010.010.1110100PERCENT PASSING (%)PARTICLE SIZE (mm)U. S. STANDARD SIEVE SIZE2"1"3/4"1/2"3/8"481016203040501002001.5"------- ---r::: -::: -r--.. ~ F::: t:---...._ ~ ......... ......... ~ ~ I ' \ ' \ \ ' \ ' \ \_ ' 1"-r-,. "'r--• ~ Construction Testing & Engineering, Inc. • CT~c 1441 Montiel Rd Ste 115, Escondido, CA 92026 Ph (760) 746-4955 ■
APPENDIX D
STANDARD SPECIFICATIONS FOR GRADING
Appendix D
Standard Specifications for Grading
STANDARD SPECIFICATIONS OF GRADING
Page 1 of 26
Page D-1
Section 1 - General
Construction Testing & Engineering, Inc. presents the following standard recommendations for
grading and other associated operations on construction projects. These guidelines should be
considered a portion of the project specifications. Recommendations contained in the body of
the previously presented soils report shall supersede the recommendations and or requirements as
specified herein. The project geotechnical consultant shall interpret disputes arising out of
interpretation of the recommendations contained in the soils report or specifications contained
herein.
Section 2 - Responsibilities of Project Personnel
The geotechnical consultant should provide observation and testing services sufficient to general
conformance with project specifications and standard grading practices. The geotechnical
consultant should report any deviations to the client or his authorized representative.
The Client should be chiefly responsible for all aspects of the project. He or his authorized
representative has the responsibility of reviewing the findings and recommendations of the
geotechnical consultant. He shall authorize or cause to have authorized the Contractor and/or
other consultants to perform work and/or provide services. During grading the Client or his
authorized representative should remain on-site or should remain reasonably accessible to all
concerned parties in order to make decisions necessary to maintain the flow of the project.
The Contractor is responsible for the safety of the project and satisfactory completion of all
grading and other associated operations on construction projects, including, but not limited to,
earth work in accordance with the project plans, specifications and controlling agency
requirements.
Section 3 - Preconstruction Meeting
A preconstruction site meeting should be arranged by the owner and/or client and should include
the grading contractor, design engineer, geotechnical consultant, owner’s representative and
representatives of the appropriate governing authorities.
Section 4 - Site Preparation
The client or contractor should obtain the required approvals from the controlling authorities for
the project prior, during and/or after demolition, site preparation and removals, etc. The
appropriate approvals should be obtained prior to proceeding with grading operations.
Appendix D
Standard Specifications for Grading
STANDARD SPECIFICATIONS OF GRADING
Page 2 of 26
Page D-2
Clearing and grubbing should consist of the removal of vegetation such as brush, grass, woods,
stumps, trees, root of trees and otherwise deleterious natural materials from the areas to be
graded. Clearing and grubbing should extend to the outside of all proposed excavation and fill
areas.
Demolition should include removal of buildings, structures, foundations, reservoirs, utilities
(including underground pipelines, septic tanks, leach fields, seepage pits, cisterns, mining shafts,
tunnels, etc.) and other man-made surface and subsurface improvements from the areas to be
graded. Demolition of utilities should include proper capping and/or rerouting pipelines at the
project perimeter and cutoff and capping of wells in accordance with the requirements of the
governing authorities and the recommendations of the geotechnical consultant at the time of
demolition.
Trees, plants or man-made improvements not planned to be removed or demolished should be
protected by the contractor from damage or injury.
Debris generated during clearing, grubbing and/or demolition operations should be wasted from
areas to be graded and disposed off-site. Clearing, grubbing and demolition operations should be
performed under the observation of the geotechnical consultant.
Section 5 - Site Protection
Protection of the site during the period of grading should be the responsibility of the contractor.
Unless other provisions are made in writing and agreed upon among the concerned parties,
completion of a portion of the project should not be considered to preclude that portion or
adjacent areas from the requirements for site protection until such time as the entire project is
complete as identified by the geotechnical consultant, the client and the regulating agencies.
Precautions should be taken during the performance of site clearing, excavations and grading to
protect the work site from flooding, ponding or inundation by poor or improper surface drainage.
Temporary provisions should be made during the rainy season to adequately direct surface
drainage away from and off the work site. Where low areas cannot be avoided, pumps should be
kept on hand to continually remove water during periods of rainfall.
Rain related damage should be considered to include, but may not be limited to, erosion, silting,
saturation, swelling, structural distress and other adverse conditions as determined by the
geotechnical consultant. Soil adversely affected should be classified as unsuitable materials and
should be subject to overexcavation and replacement with compacted fill or other remedial
grading as recommended by the geotechnical consultant.
Appendix D
Standard Specifications for Grading
STANDARD SPECIFICATIONS OF GRADING
Page 3 of 26
Page D-3
The contractor should be responsible for the stability of all temporary excavations.
Recommendations by the geotechnical consultant pertaining to temporary excavations (e.g.,
backcuts) are made in consideration of stability of the completed project and, therefore, should
not be considered to preclude the responsibilities of the contractor. Recommendations by the
geotechnical consultant should not be considered to preclude requirements that are more
restrictive by the regulating agencies. The contractor should provide during periods of extensive
rainfall plastic sheeting to prevent unprotected slopes from becoming saturated and unstable.
When deemed appropriate by the geotechnical consultant or governing agencies the contractor
shall install checkdams, desilting basins, sand bags or other drainage control measures.
In relatively level areas and/or slope areas, where saturated soil and/or erosion gullies exist to
depths of greater than 1.0 foot; they should be overexcavated and replaced as compacted fill in
accordance with the applicable specifications. Where affected materials exist to depths of 1.0
foot or less below proposed finished grade, remedial grading by moisture conditioning in-place,
followed by thorough recompaction in accordance with the applicable grading guidelines herein
may be attempted. If the desired results are not achieved, all affected materials should be
overexcavated and replaced as compacted fill in accordance with the slope repair
recommendations herein. If field conditions dictate, the geotechnical consultant may
recommend other slope repair procedures.
Section 6 - Excavations
6.1 Unsuitable Materials
Materials that are unsuitable should be excavated under observation and
recommendations of the geotechnical consultant. Unsuitable materials include, but may
not be limited to, dry, loose, soft, wet, organic compressible natural soils and fractured,
weathered, soft bedrock and nonengineered or otherwise deleterious fill materials.
Material identified by the geotechnical consultant as unsatisfactory due to its moisture
conditions should be overexcavated; moisture conditioned as needed, to a uniform at or
above optimum moisture condition before placement as compacted fill.
If during the course of grading adverse geotechnical conditions are exposed which were
not anticipated in the preliminary soil report as determined by the geotechnical consultant
additional exploration, analysis, and treatment of these problems may be recommended.
Appendix D
Standard Specifications for Grading
STANDARD SPECIFICATIONS OF GRADING
Page 4 of 26
Page D-4
6.2 Cut Slopes
Unless otherwise recommended by the geotechnical consultant and approved by the
regulating agencies, permanent cut slopes should not be steeper than 2:1 (horizontal:
vertical).
The geotechnical consultant should observe cut slope excavation and if these excavations
expose loose cohesionless, significantly fractured or otherwise unsuitable material, the
materials should be overexcavated and replaced with a compacted stabilization fill. If
encountered specific cross section details should be obtained from the Geotechnical
Consultant.
When extensive cut slopes are excavated or these cut slopes are made in the direction of
the prevailing drainage, a non-erodible diversion swale (brow ditch) should be provided
at the top of the slope.
6.3 Pad Areas
All lot pad areas, including side yard terrace containing both cut and fill materials,
transitions, located less than 3 feet deep should be overexcavated to a depth of 3 feet and
replaced with a uniform compacted fill blanket of 3 feet. Actual depth of overexcavation
may vary and should be delineated by the geotechnical consultant during grading,
especially where deep or drastic transitions are present.
For pad areas created above cut or natural slopes, positive drainage should be established
away from the top-of-slope. This may be accomplished utilizing a berm drainage swale
and/or an appropriate pad gradient. A gradient in soil areas away from the top-of-slopes
of 2 percent or greater is recommended.
Section 7 - Compacted Fill
All fill materials should have fill quality, placement, conditioning and compaction as specified
below or as approved by the geotechnical consultant.
7.1 Fill Material Quality
Excavated on-site or import materials which are acceptable to the geotechnical consultant
may be utilized as compacted fill, provided trash, vegetation and other deleterious
materials are removed prior to placement. All import materials anticipated for use on-site
should be sampled tested and approved prior to and placement is in conformance with the
requirements outlined.
Appendix D
Standard Specifications for Grading
STANDARD SPECIFICATIONS OF GRADING
Page 5 of 26
Page D-5
Rocks 12 inches in maximum and smaller may be utilized within compacted fill provided
sufficient fill material is placed and thoroughly compacted over and around all rock to
effectively fill rock voids. The amount of rock should not exceed 40 percent by dry
weight passing the 3/4-inch sieve. The geotechnical consultant may vary those
requirements as field conditions dictate.
Where rocks greater than 12 inches but less than four feet of maximum dimension are
generated during grading, or otherwise desired to be placed within an engineered fill,
special handling in accordance with the recommendations below. Rocks greater than
four feet should be broken down or disposed off-site.
7.2 Placement of Fill
Prior to placement of fill material, the geotechnical consultant should observe and
approve the area to receive fill. After observation and approval, the exposed ground
surface should be scarified to a depth of 6 to 8 inches. The scarified material should be
conditioned (i.e. moisture added or air dried by continued discing) to achieve a moisture
content at or slightly above optimum moisture conditions and compacted to a minimum
of 90 percent of the maximum density or as otherwise recommended in the soils report or
by appropriate government agencies.
Compacted fill should then be placed in thin horizontal lifts not exceeding eight inches in
loose thickness prior to compaction. Each lift should be moisture conditioned as needed,
thoroughly blended to achieve a consistent moisture content at or slightly above optimum
and thoroughly compacted by mechanical methods to a minimum of 90 percent of
laboratory maximum dry density. Each lift should be treated in a like manner until the
desired finished grades are achieved.
The contractor should have suitable and sufficient mechanical compaction equipment and
watering apparatus on the job site to handle the amount of fill being placed in
consideration of moisture retention properties of the materials and weather conditions.
When placing fill in horizontal lifts adjacent to areas sloping steeper than 5:1 (horizontal:
vertical), horizontal keys and vertical benches should be excavated into the adjacent slope
area. Keying and benching should be sufficient to provide at least six-foot wide benches
and a minimum of four feet of vertical bench height within the firm natural ground, firm
bedrock or engineered compacted fill. No compacted fill should be placed in an area
after keying and benching until the geotechnical consultant has reviewed the area.
Material generated by the benching operation should be moved sufficiently away from
Appendix D
Standard Specifications for Grading
STANDARD SPECIFICATIONS OF GRADING
Page 6 of 26
Page D-6
the bench area to allow for the recommended review of the horizontal bench prior to
placement of fill.
Within a single fill area where grading procedures dictate two or more separate fills,
temporary slopes (false slopes) may be created. When placing fill adjacent to a false
slope, benching should be conducted in the same manner as above described. At least a
3-foot vertical bench should be established within the firm core of adjacent approved
compacted fill prior to placement of additional fill. Benching should proceed in at least
3-foot vertical increments until the desired finished grades are achieved.
Prior to placement of additional compacted fill following an overnight or other grading
delay, the exposed surface or previously compacted fill should be processed by
scarification, moisture conditioning as needed to at or slightly above optimum moisture
content, thoroughly blended and recompacted to a minimum of 90 percent of laboratory
maximum dry density. Where unsuitable materials exist to depths of greater than one
foot, the unsuitable materials should be over-excavated.
Following a period of flooding, rainfall or overwatering by other means, no additional fill
should be placed until damage assessments have been made and remedial grading
performed as described herein.
Rocks 12 inch in maximum dimension and smaller may be utilized in the compacted fill
provided the fill is placed and thoroughly compacted over and around all rock. No
oversize material should be used within 3 feet of finished pad grade and within 1 foot of
other compacted fill areas. Rocks 12 inches up to four feet maximum dimension should
be placed below the upper 10 feet of any fill and should not be closer than 15 feet to any
slope face. These recommendations could vary as locations of improvements dictate.
Where practical, oversized material should not be placed below areas where structures or
deep utilities are proposed. Oversized material should be placed in windrows on a clean,
overexcavated or unyielding compacted fill or firm natural ground surface. Select native
or imported granular soil (S.E. 30 or higher) should be placed and thoroughly flooded
over and around all windrowed rock, such that voids are filled. Windrows of oversized
material should be staggered so those successive strata of oversized material are not in
the same vertical plane.
It may be possible to dispose of individual larger rock as field conditions dictate and as
recommended by the geotechnical consultant at the time of placement.
Appendix D
Standard Specifications for Grading
STANDARD SPECIFICATIONS OF GRADING
Page 7 of 26
Page D-7
The contractor should assist the geotechnical consultant and/or his representative by
digging test pits for removal determinations and/or for testing compacted fill. The
contractor should provide this work at no additional cost to the owner or contractor's
client.
Fill should be tested by the geotechnical consultant for compliance with the
recommended relative compaction and moisture conditions. Field density testing should
conform to ASTM Method of Test D 1556-00, D 2922-04. Tests should be conducted at
a minimum of approximately two vertical feet or approximately 1,000 to 2,000 cubic
yards of fill placed. Actual test intervals may vary as field conditions dictate. Fill found
not to be in conformance with the grading recommendations should be removed or
otherwise handled as recommended by the geotechnical consultant.
7.3 Fill Slopes
Unless otherwise recommended by the geotechnical consultant and approved by the
regulating agencies, permanent fill slopes should not be steeper than 2:1 (horizontal:
vertical).
Except as specifically recommended in these grading guidelines compacted fill slopes
should be over-built two to five feet and cut back to grade, exposing the firm, compacted
fill inner core. The actual amount of overbuilding may vary as field conditions dictate. If
the desired results are not achieved, the existing slopes should be overexcavated and
reconstructed under the guidelines of the geotechnical consultant. The degree of
overbuilding shall be increased until the desired compacted slope surface condition is
achieved. Care should be taken by the contractor to provide thorough mechanical
compaction to the outer edge of the overbuilt slope surface.
At the discretion of the geotechnical consultant, slope face compaction may be attempted
by conventional construction procedures including backrolling. The procedure must
create a firmly compacted material throughout the entire depth of the slope face to the
surface of the previously compacted firm fill intercore.
During grading operations, care should be taken to extend compactive effort to the outer
edge of the slope. Each lift should extend horizontally to the desired finished slope
surface or more as needed to ultimately established desired grades. Grade during
construction should not be allowed to roll off at the edge of the slope. It may be helpful
to elevate slightly the outer edge of the slope. Slough resulting from the placement of
individual lifts should not be allowed to drift down over previous lifts. At intervals not
Appendix D
Standard Specifications for Grading
STANDARD SPECIFICATIONS OF GRADING
Page 8 of 26
Page D-8
exceeding four feet in vertical slope height or the capability of available equipment,
whichever is less, fill slopes should be thoroughly dozer trackrolled.
For pad areas above fill slopes, positive drainage should be established away from the
top-of-slope. This may be accomplished using a berm and pad gradient of at least two
percent.
Section 8 - Trench Backfill
Utility and/or other excavation of trench backfill should, unless otherwise recommended, be
compacted by mechanical means. Unless otherwise recommended, the degree of compaction
should be a minimum of 90 percent of the laboratory maximum density.
Within slab areas, but outside the influence of foundations, trenches up to one foot wide and two
feet deep may be backfilled with sand and consolidated by jetting, flooding or by mechanical
means. If on-site materials are utilized, they should be wheel-rolled, tamped or otherwise
compacted to a firm condition. For minor interior trenches, density testing may be deleted or
spot testing may be elected if deemed necessary, based on review of backfill operations during
construction.
If utility contractors indicate that it is undesirable to use compaction equipment in close
proximity to a buried conduit, the contractor may elect the utilization of light weight mechanical
compaction equipment and/or shading of the conduit with clean, granular material, which should
be thoroughly jetted in-place above the conduit, prior to initiating mechanical compaction
procedures. Other methods of utility trench compaction may also be appropriate, upon review of
the geotechnical consultant at the time of construction.
In cases where clean granular materials are proposed for use in lieu of native materials or where
flooding or jetting is proposed, the procedures should be considered subject to review by the
geotechnical consultant. Clean granular backfill and/or bedding are not recommended in slope
areas.
Section 9 - Drainage
Where deemed appropriate by the geotechnical consultant, canyon subdrain systems should be
installed in accordance with CTE’s recommendations during grading.
Typical subdrains for compacted fill buttresses, slope stabilization or sidehill masses, should be
installed in accordance with the specifications.
Appendix D
Standard Specifications for Grading
STANDARD SPECIFICATIONS OF GRADING
Page 9 of 26
Page D-9
Roof, pad and slope drainage should be directed away from slopes and areas of structures to
suitable disposal areas via non-erodible devices (i.e., gutters, downspouts, and concrete swales).
For drainage in extensively landscaped areas near structures, (i.e., within four feet) a minimum
of 5 percent gradient away from the structure should be maintained. Pad drainage of at least 2
percent should be maintained over the remainder of the site.
Drainage patterns established at the time of fine grading should be maintained throughout the life
of the project. Property owners should be made aware that altering drainage patterns could be
detrimental to slope stability and foundation performance.
Section 10 - Slope Maintenance
10.1 - Landscape Plants
To enhance surficial slope stability, slope planting should be accomplished at the
completion of grading. Slope planting should consist of deep-rooting vegetation
requiring little watering. Plants native to the southern California area and plants relative
to native plants are generally desirable. Plants native to other semi-arid and arid areas
may also be appropriate. A Landscape Architect should be the best party to consult
regarding actual types of plants and planting configuration.
10.2 - Irrigation
Irrigation pipes should be anchored to slope faces, not placed in trenches excavated into
slope faces.
Slope irrigation should be minimized. If automatic timing devices are utilized on
irrigation systems, provisions should be made for interrupting normal irrigation during
periods of rainfall.
10.3 - Repair
As a precautionary measure, plastic sheeting should be readily available, or kept on hand,
to protect all slope areas from saturation by periods of heavy or prolonged rainfall. This
measure is strongly recommended, beginning with the period prior to landscape planting.
If slope failures occur, the geotechnical consultant should be contacted for a field review
of site conditions and development of recommendations for evaluation and repair.
If slope failures occur as a result of exposure to period of heavy rainfall, the failure areas
and currently unaffected areas should be covered with plastic sheeting to protect against
additional saturation.
Appendix D
Standard Specifications for Grading
STANDARD SPECIFICATIONS OF GRADING
Page 10 of 26
Page D-10
In the accompanying Standard Details, appropriate repair procedures are illustrated for
superficial slope failures (i.e., occurring typically within the outer one foot to three feet of
a slope face).
FINISH CUT
SLOPE
----
5'MIN
-----------
BENCHING FILL OVER NATURAL
FILL SLOPE
10'
TYPICAL
SURFACE OF FIRM
EARTH MATERIAL
15' MIN. {INCLINED 2% MIN. INTO SLOPE)
BENCHING FILL OVER CUT
FINISH FILL SLOPE
SURFACE OF FIRM
EARTH MATERIAL
15' MIN OR STABILITY EQUIVALENT PER SOIL
ENGINEERING (INCLINED 2% MIN. INTO SLOPE)
NOTTO SCALE
BENCHING FOR COMPACTED FILL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 11 of 26
--
---
MINIMUM
DOWNSLOPE
KEY DEPTH
TOE OF SLOPE SHOWN
ON GRADING PLAN
FILL __ --------------
-------~ ...... --~ -__ .,,,,,. ~'\~~~ .,,,,,..,,,,,..,,,,,.
.,,,,,. ~~~ .,,,,,..,,,,,. .,,,,,..,,,,,..,,,,,. ~~~~ .,,,,,..,,,,,. _.,,,,,. :"\~~\.; .,,,,,..,,,,,. _.,,,,,. ~sux ~_.,,,,,. _________ _
---\j .,,,,,. .,,,,,. .,,,,,. .,,,,,. 1 O' TYPICAL BENCH
// .,,,,,. .,,,,,. .,,,,,. WIDTH VARIES
4'
~1 .,,,,,..,,,,,..,,,,,.
/ 1 __ .,,,,,..,,,,,. COMPETENT EARTH
/ --MATERIAL -
2% MIN ---
15' MINIMUM BASE KEY WIDTH
TYPICAL BENCH
HEIGHT
PROVIDE BACKDRAIN AS REQUIRED
PER RECOMMENDATIONS OF SOILS
ENGINEER DURING GRADING
WHERE NATURAL SLOPE GRADIENT IS 5:1 OR LESS,
BENCHING IS NOT NECESSARY. FILL IS NOT TO BE
PLACED ON COMPRESSIBLE OR UNSUITABLE MATERIAL.
NOT TO SCALE
FILL SLOPE ABOVE NATURAL GROUND DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 12 of 26
U) ~ z CJ ► Jl CJ U) ""CJ ""CJ m Ill(") cc -CD Jl ...I.(") w► 0 :::! -h 0 I\) z C) U) "Tl 0 Jl Ci) ~ CJ z Ci) -REMOVE ALL TOPSOIL, COLLUVIUM, AND CREEP MATERIAL FROM TRANSITION CUT/FILL CONTACT SHOWN ON GRADING PLAN CUT/FILL CONTACT SHOWN ON "AS-BUILT" NATURAL __ TOPOGRAP~Y __ ---------_ --CUT SLOPE* --------- - ---;_? ~€.\\!lo\J€. FILL ------:::-ul<l~ocl'.€ --------col.l--\)v' ...... --,o?so\\._:.. - - - - ---1 rr~---------14'TYPIGAL I ---2%MIN --15' MINIMUM NOTTO SCALE 10' TYPICAL BEDROCK OR APPROVED FOUNDATION MATERIAL *NOTE: CUT SLOPE PORTION SHOULD BE MADE PRIOR TO PLACEMENT OF FILL FILL SLOPE ABOVE CUT SLOPE DETAIL ----
[
SURFACEOF
COMPETENT
MATERIAL
--~-------------~ -..... ' ,,,,,, .,,,,,.
\'\ COMPACTED FILL /'/
\\ //
\ /
TYPICAL BENCHING \ \ /
\' / / ....___ , _,,,,,, A...-~
SEE DETAIL BELOW
MINIMUM 9 FT3 PER LINEAR FOOT
OF APPROVED FILTER MATERIAL
CAL TRANS CLASS 2 PERMEABLE MATERIAL
FILTER MATERIAL TO MEET FOLLOWING
SPECIFICATION OR APPROVED EQUAL:
' / REMOVE UNSUITABLE
DETAIL
14"
MATERIAL
INCLINE TOWARD DRAIN
AT 2% GRADIENT MINIMUM
MINIMUM 4" DIAMETER APPROVED
PERFORATED PIPE (PERFORATIONS
DOWN)
6" FILTER MATERIAL BEDDING
SIEVE SIZE PERCENTAGE PASSING
APPROVED PIPE TO BE SCHEDULE 40
POLY-VINYL-CHLORIDE (P.V.C.) OR
APPROVED EQUAL. MINIMUM CRUSH
STRENGTH 1000 psi
1"
¾"
¾"
NO.4
NO.8
NO. 30
NO. 50
NO. 200
100
90-100
40-100
25-40
18-33
5-15
0-7
0-3
PIPE DIAMETER TO MEET THE
FOLLOWING CRITERIA, SUBJECT TO
FIELD REVIEW BASED ON ACTUAL
GEOTECHNICAL CONDITIONS
ENCOUNTERED DURING GRADING
LENGTH OF RUN
NOTTO SCALE
INITIAL 500'
500' TO 1500'
> 1500'
PIPE DIAMETER
4"
6"
8"
TYPICAL CANYON SUBDRAIN DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 14 of 26
TYPICAL BENCHING
CANYON SUBDRAIN DETAILS
--""' ----,, ,,,,,..,,,
[
SURFACEOF
COMPETENT
MATERIAL
,'' COMPACTED FILL / ~
\\ //
\ /
\ \ / ,, // --,_,,,,,. __ ..._
' / REMOVE UNSUITABLE
MATERIAL
SEE DETAILS BELOW
TRENCH DETAILS
6" MINIMUM OVERLAP
INCLINE TOWARD DRAIN
AT 2% GRADIENT MINIMUM
OPTIONAL V-DITCH DETAIL MINIMUM 9 FP PER LINEAR FOOT
OF APPROVED DRAIN MATERIAL
MIRAFI 140N FABRIC
OR APPROVED EQUAL
6" MINIMUM OVERLAP --------0
24"
MINIMUM
MIRAFI 140N FABRIC
OR APPROVED EQUAL
APPROVED PIPE TO BE
SCHEDULE 40 POLY-
VINYLCHLORIDE (P.V.C.)
24"
MINIMUM
MINIMUM 9 FP PER LINEAR FOOT
OF APPROVED DRAIN MATERIAL
OR APPROVED EQUAL.
MINIMUM CRUSH STRENGTH
1000 PSI.
DRAIN MATERIAL TO MEET FOLLOWING
SPECIFICATION OR APPROVED EQUAL:
PIPE DIAMETER TO MEET THE
FOLLOWING CRITERIA, SUBJECT TO
FIELD REVIEW BASED ON ACTUAL
GEOTECHNICAL CONDITIONS
ENCOUNTERED DURING GRADING
SIEVE SIZE
1 ½"
1"
¾"
¾"
NO. 200
PERCENTAGE PASSING
88-100
5-40
0-17
0-7
0-3
LENGTH OF RUN
INITIAL 500'
500' TO 1500'
> 1500'
NOT TO SCALE
GEOFABRIC SUBDRAIN
STANDARD SPECIFICATIONS FOR GRADING
Page 15 of 26
PIPE DIAMETER
4"
6"
8"
FRONT VIEW
CONCRETE
CUT-OFF WALL
SUBDRAIN PIPE
SIDE VIEW
-•. . . _,.. -, .. -.. -. .-, .... , ... , l!trr.'' ltt.'' t..'' ... . ' 6" Min. ....
. ' .. ----~---· ·-·-~ 6" Min.
24" Min.
6" Min.
~ 12" Min.~ 6" Min.
CONCRETE CUT-OFF WALL __ _..,• .• -:..►.-.. • . ' ... ' 6" Min .
-... -...
SOILD SUBDRAIN PIPE
•.-, ., "' 'i "' ' PERFORATED SUBDRAIN PIPE . ' . ' . . . . . .
NOT TO SCALE
RECOMMENDED SUBDRAIN CUT-OFF WALL
STANDARD SPECIFICATIONS FOR GRADING
Page 16 of 26
FRONT VIEW
SUBDRAIN OUTLET
PIPE (MINIMUM 4" DIAMETER)
SIDE VIEW
ALL BACKFILL SHOULD BE COMPACTED
IN CONFORMANCE WITH PROJECT
SPECIFICATIONS. COMPACTION EFFORT
SHOULD NOT DAMAGE STRUCTURE
I • '
-• I I
► -'► -'► - , ,·b.. ,·brr.. ,·brr. •
.!,. • ' .... • ' i" . '
► -'► -'►-, ,, • b. ' ' • b. • ' ' brr. •
.:i.,,6,,6,, -... . -.... -....
► - , ► - , ►-,
,, I b. I 1, I b. I ' I brr. I
.i0rr..,.i0rr..,.6..,
t---24" Min.
>----24" Min.
NOTE: HEADWALL SHOULD OUTLET AT TOE OF SLOPE
OR INTO CONTROLLED SURFACE DRAINAGE DEVICE
ALL DISCHARGE SHOULD BE CONTROLLED
THIS DETAIL IS A MINIMUM DESIGN AND MAY BE
MODIFIED DEPENDING UPON ENCOUNTERED
CONDITIONS AND LOCAL REQUIREMENTS
NOT TO SCALE
24" Min.
12"
TYPICAL SUBDRAIN OUTLET HEADWALL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 17 of 26
4" DIAMETER PERFORATED
PIPE BACKDRAIN
4" DIAMETER NON-PERFORATED
PIPE LATERAL DRAIN
SLOPE PER PLAN
FILTER MATERIAL BENCHING
AN ADDITIONAL BACKDRAIN
AT MID-SLOPE WILL BE REQUIRED FOR
SLOPE IN EXCESS OF 40 FEET HIGH.
KEY-DIMENSION PER SOILS ENGINEER
(GENERALLY 1/2 SLOPE HEIGHT, 15' MINIMUM)
DIMENSIONS ARE MINIMUM RECOMMENDED
NOT TO SCALE
TYPICAL SLOPE STABILIZATION FILL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 18 of 26
4" DIAMETER PERFORATED
PIPE BACKDRAIN
4" DIAMETER NON-PERFORATED
PIPE LATERAL DRAIN
SLOPE PER PLAN
FILTER MATERIAL
2%MIN 1 1
'
........,.._I I I 111 I 11-
1 I
'
BENCHING
H/2
~1 ===.. ~. IFF.:,=, ,:rr· 1 "'T""'!, ........ , • ,......,_JI" I · ADDITIONAL BACKDRAIN AT
MID-SLOPE WILL BE REQUIRED
FOR SLOPE IN EXCESS OF 40
FEET HIGH.
KEY-DIMENSION PER SOILS ENGINEER
DIMENSIONS ARE MINIMUM RECOMMENDED
NOTTO SCALE
TYPICAL BUTTRESS FILL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 19 of 26
20' MAXIMUM
FINAL LIMIT OF
EXCAVATION
OVEREXCAVATE
OVERBURDEN
(CREEP-PRONE)
DAYLIGHT
LINE
FINISH PAD
OVEREXCAVATE 3'
AND REPLACE WITH
COMPACTED FILL
COMPETENT BEDROCK
TYPICAL BENCHING
LOCATION OF BACKDRAIN AND
OUTLETS PER SOILS ENGINEER
AND/OR ENGINEERING GEOLOGIST
DURING GRADING. MINIMUM 2%
FLOW GRADIENT TO DISCHARGE
LOCATION.
EQUIPMENT WIDTH (MINIMUM 15')
NOTTO SCALE
DAYLIGHT SHEAR KEY DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 20 of 26
NATURAL GROUND
PROPOSED GRADING
------------------COMPACTED FILL -----------------------------------------------
PROVIDE BACKDRAIN, PER
BACKDRAIN DETAIL. AN
ADDITIONAL BACKDRAIN
AT MID-SLOPE WILL BE
REQUIRED FOR BACK
SLOPES IN EXCESS OF BASE WIDTH "W" DETERMINED
BY SOILS ENGINEER
NOTTO SCALE
40 FEET HIGH. LOCATIONS
OF BACKDRAINS AND OUTLETS
PER SOILS ENGINEER AND/OR
ENGINEERING GEOLOGIST
DURING GRADING. MINIMUM 2%
FLOW GRADIENT TO DISCHARGE
LOCATION.
TYPICAL SHEAR KEY DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 21 of 26
FINISH SURFACE SLOPE
3 FT3 MINIMUM PER LINEAR FOOT
APPROVED FILTER ROCK*
CONCRETE COLLAR
PLACED NEAT
A
COMPACTED FILL
2.0% MINIMUM GRADIENT
A
4" MINIMUM DIAMETER
SOLID OUTLET PIPE
SPACED PER SOIL
ENGINEER REQUIREMENTS
4" MINIMUM APPROVED
PERFORATED PIPE**
(PERFORATIONS DOWN)
MINIMUM 2% GRADIENT
TO OUTLET
DURING GRADING TYPICAL BENCH INCLINED
TOWARD DRAIN
**APPROVED PIPE TYPE:
MINIMUM
12" COVER
SCHEDULE 40 POLYVINYL CHLORIDE
(P.V.C.) OR APPROVED EQUAL.
MINIMUM CRUSH STRENGTH 1000 PSI
BENCHING
DETAIL A-A
OMPACTE
BACKFILL
12"
MINIMUM
TEMPORARY FILL LEVEL
MINIMUM 4" DIAMETER APPROVED
SOLID OUTLET PIPE
*FILTER ROCK TO MEET FOLLOWING
SPECIFICATIONS OR APPROVED EQUAL:
SIEVE SIZE
1"
¾"
¾"
N0.4
NO. 30
NO. 50
NO. 200
PERCENTAGE PASSING
100
90-100
40-100
25-40
5-15
0-7
0-3
NOTTO SCALE
TYPICAL BACKDRAIN DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 22 of 26
FINISH SURFACE SLOPE
MINIMUM 3 FT3 PER LINEAR FOOT
OPEN GRADED AGGREGATE*
TAPE AND SEAL AT COVER
CONCRETE COLLAR
PLACED NEAT COMPACTED FILL
A
2.0% MINIMUM GRADIENT
A
MINIMUM 4" DIAMETER
SOLID OUTLET PIPE
SPACED PER SOIL
ENGINEER REQUIREMENTS
MINIMUM
12" COVER
*NOTE: AGGREGATE TO MEET FOLLOWING
SPECIFICATIONS OR APPROVED EQUAL:
SIEVE SIZE PERCENTAGE PASSING
1 ½" 100
1" 5-40
¾" 0-17
¾" 0-7
NO. 200 0-3
TYPICAL
BENCHING
DETAIL A-A
OMPACTE
BACKFILL
12"
MINIMUM
NOT TO SCALE
MIRAFI 140N FABRIC OR
APPROVED EQUAL
4" MINIMUM APPROVED
PERFORATED PIPE
(PERFORATIONS DOWN)
MINIMUM 2% GRADIENT
TO OUTLET
BENCH INCLINED
TOWARD DRAIN
TEMPORARY FILL LEVEL
MINIMUM 4" DIAMETER APPROVED
SOLID OUTLET PIPE
BACKDRAIN DETAIL (GEOFRABIC)
STANDARD SPECIFICATIONS FOR GRADING
Page 23 of 26
SOIL SHALL BE PUSHED OVER
ROCKS AND FLOODED INTO
VOIDS. COMPACT AROUND
AND OVER EACH WINDROW.
10'
i FILL SLOPE 1
CLEAR ZONE __/
EQUIPMENT WIDTH
STACK BOULDERS END TO END.
DO NOT PILE UPON EACH OTHER.
0 0
0 0
~ 10' MIN O
NOT TO SCALE
0
ROCK DISPOSAL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 24 of 26
STAGGER
ROWS
FINISHED GRADE BUILDING
10'
SLOPE FACE
0
NO OVERSIZE, AREA FOR
FOUNDATION, UTILITIE~~l
AND SWIMMING POOL:_i_
0 0
STREET 1--d 4•L-.
WINDROW~
0
5' MINIMUM OR BELOW
DEPTH OF DEEPEST
UTILITY TRENCH
(WHICHEVER GREATER)
TYPICAL WINDROW DETAIL (EDGE VIEW)
GRANULAR SOIL FLOODED
TO FILL VOIDS
HORIZONTALLY PLACED
COMPACTION FILL
PROFILE VIEW
NOT TO SCALE
ROCK DISPOSAL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 25 of 26
GENERAL GRADING RECOMMENDATIONS
CUTLOT
------------
------, --UNWEATHERED BEDROCK
OVEREXCAVATE
AND REGRADE
COMPACTED FILL
~
-----TOPSOIL, COLLUVIUM
,--AND WEATHERED
.,
BEDROCK ,,.-
----,,.-
CUT/FILL LOT (TRANSITION)
~
~ ----
UNWEATHERED BEDROCK
NOT TO SCALE
TRANSITION LOT DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 26 of 26
_.......-:: ORIGINAL
,,. ,,. ,,. ,,. , GROUND
'MIN
3'MIN
OVEREXCAVATE
AND REGRADE
APPENDIX E
C.4-1 WORKSHEET
.. • I ■ .::..
Worksheet C.4-1: Categorization of Inftltration Feasibility Condition
-" -----" - - -----... lffi■r.liil , • .., ••. • .. llH!EI-.,1111u.•n-n11u1■ • 11 ...
Part 1 -Full Infiltration Feasibility Screening Criteria
Would infiltration of the full design volume be feasible from a physical perspective without any undesirable
consequences that cannot be reasonably mitigated?
Criteria Screening Question
1
Is the estimated reliable infiltration rate below proposed facility locations
greater than 0.5 inches per hour? The response to this Screening Question shall
be based on a comprehensive evaluation of the factors presented in Appendix
C.2 and Appendix D .
Provide basis:
Yes No
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability.
2
Can infiltration greater than 0.5 inches per hour be allowed without increasing
risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or
other factors) that cannot be mitigated to an acceptable level? The response to
this Screening Question shall be based on a comprehensive evaluation of the
factors presented in Appendix C.2.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability.
C-11
Appendix C: Geotechnical and Groundwater Investigation Requirements
Criteria Screening Question
3
Can infiltration greater than 0.5 inches per hour be allowed without increasing
risk of groundwater contamination (shallow water table, storm water pollutants
or other factors) that cannot be mitigated to an acceptable level? The response
to this Screening Question shall be based on a comprehensive evaluation of the
factors presented in Appendix C.3.
Provide basis:
Yes No
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability.
4
Can infiltration greater than 0.5 inches per hour be allowed without causing
potential water balance issues such as change of seasonality of ephemeral
streams or increased discharge of contaminated groundwater to surface waters?
The response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability.
Part 1
If all answers to rows 1 - 4 are "Yes" a full infiltration design is potentially feasible. The
feasibility screening category is Full Infiltration
Result* If any answer from row 1-4 is "No", infiltration may be possible to some extent but
would not generally be feasible or desirable to achieve a "full infiltration" design.
Proceed to Part 2
*To be completed using gathered site information and best professional judgment considering the definition of MEP in
the MS4 Permit. Additional testing and/ or studies may be required by City Engineer to substantiate findings.
C-12
Appendix C: Geotechnical and Groundwater Investigation Requirements
Part 2 -Partial Infiltration vs. No Infiltration Feasibility Screening Criteria
Would infiltration of water in any appreciable amount be physically feasible without any negative
consequences that cannot be reasonably mitigated?
Criteria Screening Question
5
Do soil and geologic conditions allow for infiltration in any appreciable rate or
volume? The response to this Screening Question shall be based on a
comprehensive evaluation of the factors presented in Appendix C.2 and
AppendixD.
Provide basis:
Yes No
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability and why it was not feasible to mitigate low
infiltration rates.
6
Can Infiltration in any appreciable quantity be allowed without increasing risk
of geotechnical hazards (slope stability, groundwater mounding, utilities, or
other factors) that cannot be mitigated to an acceptable level? The response to
this Screening Question shall be based on a comprehensive evaluation of the
factors presented in Appendix C.2.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability and why it was not feasible to mitigate low
infiltration rates.
C-13
Appendix C: Geotechnical and Groundwater Investigation Requirements
Criteria Screening Question
7
Can Infiltration in any appreciable quantity be allowed without posing
significant risk for groundwater related concerns (shallow water table, storm
water pollutants or other factors)? The response to this Screening Question
shall be based on a comprehensive evaluation of the factors presented in
Appendix C.3.
Provide basis:
Yes No
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability and why it was not feasible to mitigate low
infiltration rates.
8
Can infiltration be allowed without violating downstream water rights? The
response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of study/ data source applicability and why it was not feasible to mitigate low
infiltration rates.
If all answers from row 1-4 are yes then partial infiltration design is potentially feasible.
Part 2 The feasibility screening category is Partial Infiltration.
Result* If any answer from row 5-8 is no, then infiltration of any volume is considered to be
infeasible within the drainage area. The feasibility screening category is No Infiltration.
*To be completed using gathered site information and best professional judgment considering the definition of MEP in
the MS4 Permit. Additional testing and/ or studies may be required by City Engineer to substantiate findings
C-14