HomeMy WebLinkAboutPD 2020-0047; HARLE RESIDENCE; GEOTECHNICAL INVESTIGATION; 2021-02-26
GEOTECHNICAL INVESTIGATION
PROPOSED HARLE RESIDENCE
4547 COVE DRIVE
CARLSBAD, CALIFORNIA
Prepared for:
KWD HOLDINGS, LLC
ATTENTION: MR. JOHN DARLINGTON
265 VIA DEL MONTE
OCEANSIDE, CALIFORNIA 92058
Prepared by:
CONSTRUCTION TESTING & ENGINEERING, INC.
1441 MONTIEL ROAD, SUITE 115
ESCONDIDO, CALIFORNIA 92026
CTE JOB NO.: 10-15981G FEBRUARY 26, 2021
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 ............................................................................................................... 1
3.0 FIELD INVESTIGATION AND LABORATORY TESTING ................................................ 2
3.1 Field Investigation ........................................................................................................ 2
3.3 Laboratory Testing ........................................................................................................ 3
4.0 GEOLOGY ............................................................................................................................... 3
4.1 General Setting.............................................................................................................. 3
4.2 Geologic Conditions ..................................................................................................... 4
4.2.1 Quaternary Previously Placed Fill ................................................................. 4
4.2.2 Quaternary Alluvial Flood Plain Deposits ..................................................... 4
4.2.3 Tertiary Santiago Formation .......................................................................... 5
4.3 Groundwater Conditions ............................................................................................... 5
4.4 Geologic Hazards .......................................................................................................... 5
4.3.1 Surface Fault Rupture .................................................................................... 5
4.3.2 Local and Regional Faulting .......................................................................... 6
4.3.3 Liquefaction and Seismic Settlement Evaluation .......................................... 7
4.3.4 Tsunamis and Seiche Evaluation ................................................................. 10
4.3.5 Landsliding .................................................................................................. 10
4.3.6 Compressible and Expansive Soils .............................................................. 10
4.3.7 Corrosive Soils ............................................................................................. 11
5.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................. 12
5.1 General ........................................................................................................................ 12
5.2 Site Preparation ........................................................................................................... 13
5.3 Site Excavation ........................................................................................................... 15
5.4 Fill Placement and Compaction .................................................................................. 15
5.5 Fill Materials ............................................................................................................... 16
5.6 Temporary Construction Slopes ................................................................................. 17
5.7 Foundation and Slab Recommendations ..................................................................... 18
5.7.1 Auger Cast or Torque-In Style and Grade Beam Foundation Systems ....... 18
5.7.1.1 Pile Size, Embedment Depth, and Spacing ............................................... 19
5.7.1.2 Pile Vertical Bearing ................................................................................. 20
5.7.1.3 Grade Beams ............................................................................................. 20
5.7.1.4 Lateral Resistance For Auger Cast In Place Piles ..................................... 20
5.7.1.5 Foundation Settlement .............................................................................. 21
5.7.2 Spread or Mat Foundations Supported On Geosynthetic Reinforced Raft .. 21
5.7.2.1 Geosynthetic Grid Type, Depth, and Spacing .......................................... 23
5.7.2.2 Foundation Settlement .............................................................................. 24
5.7.2.3 Lateral Load Resistance ............................................................................ 24
5.7.2.4 Foundation Setback ................................................................................... 25
5.7.4 Interior Concrete Slabs ................................................................................ 25
5.8 Seismic Design Criteria .............................................................................................. 26
5.9 Lateral Resistance and Earth Pressures ....................................................................... 27
5.10 Exterior Flatwork ...................................................................................................... 29
5.11 Vehicular Pavement .................................................................................................. 30
5.12 Drainage .................................................................................................................... 31
5.12 Slopes ........................................................................................................................ 32
5.13 Controlled Low Strength Materials (CLSM) ............................................................ 33
5.14 Plan Review .............................................................................................................. 33
5.15 Construction Observation ......................................................................................... 34
6.0 LIMITATIONS OF INVESTIGATION ................................................................................. 34
FIGURES
FIGURE 1 SITE LOCATION MAP
FIGURE 2 GEOLOGIC/ EXPLORATION LOCATION MAP
FIGURE 3 REGIONAL FAULT AND SEISMICITY MAP
FIGURE 4 RETAINING WALL DRAINAGE DETAIL
FIGURE 5 FEMA FLOOD MAP
APPENDICES
APPENDIX A REFERENCES
APPENDIX B FIELD EXPLORATION METHODS AND BORING LOGS
APPENDIX C LABORATORY METHODS AND RESULTS
APPENDIX D STANDARD GRADING SPECIFICATIONS
APPENDIX E LIQUEFACTION EVALUATION
APPENDIX F I-8 INFILTRATION FEASIBILITY
Geotechnical Investigation
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February 26, 2021 CTE Job No. 10-15981G
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1.0 INTRODUCTION AND SCOPE OF SERVICES
1.1 Introduction
Construction Testing and Engineering, Inc. (CTE) has completed a geotechnical investigation and
report providing conclusions and recommendations for the proposed residential construction and
associated improvements at the subject site. CTE has performed this work in general accordance
with the terms of proposal G-5242 dated February 5, 2021. Preliminary geotechnical
recommendations for excavations, fill placement, and foundation design for the proposed
improvements are presented herein.
1.2 Scope of Services
The scope of services provided included:
Review of readily available geologic and soils reports.
Obtaining boring permits from the San Diego County Department of Environmental Health
(DEH).
Coordination of utility mark-out and location.
Excavation of exploratory borings, and soil sampling utilizing manual excavation equipment.
Cone Penetration Testing utilizing a 30-ton direct push CPT rig.
Laboratory testing of selected soil samples.
Description of the site geology and evaluation of potential geologic hazards.
Engineering and geologic analysis.
Preparation of this preliminary geotechnical report.
2.0 SITE DESCRIPTION
The subject site is located at 4547 Cove Drive in Carlsbad, California (Figure 1). The site is
bounded by neighboring residential structures to the northwest and southeast, Cove Drive to the
southwest, and an offshoot channel of the Agua Hedionda Lagoon to the northeast. The current site
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area is illustrated on Figures 1 and 2. The proposed improvement area is currently an undeveloped
lot. Based on reconnaissance and review of general site topography, it appears that the building pad
improvement area, not including the slope descending to the lagoon to the northeast, is generally flat
at an approximate elevation of 13 feet above mean sea level. The descending slope at the northeast
of the property descends from approximate elevation 13 feet msl to 0 feet msl at an approximate 2:1
(horizontal: vertical) gradient and is covered by rock/boulder “rip-rap material.”
3.0 FIELD INVESTIGATION AND LABORATORY TESTING
3.1 Field Investigation
CTE performed the recent subsurface investigation on February 10, 2021 to evaluate underlying soil
conditions in accessible representative areas adjacent to the existing building. This fieldwork
consisted of site reconnaissance, and the advancement of three Cone Penetration Tests (CPT) using a
30-ton direct push CPT rig, and the excavation of two exploratory soil borings consisting of
manually advanced hand auger excavations. CPT testing was performed to a maximum depth of
approximately 80 feet below the ground surface (bgs). The borings were advanced to a maximum
explored depth of approximately 10 feet below ground surface (bgs) and bulk samples were
collected from the cuttings. Approximate locations of the subsurface explorations are shown on the
attached Figure 2.
Soils were logged in the field by a CTE Engineering Geologist, and were visually classified in
general accordance with the Unified Soil Classification System. The field descriptions have been
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modified, where appropriate, to reflect laboratory test results. Boring logs and CPT results,
including descriptions of the soils encountered, are included in Appendix B.
3.3 Laboratory Testing
Laboratory tests were conducted on selected soil samples for classification purposes, and to evaluate
physical properties and engineering characteristics. Laboratory tests included: Expansion Index,
Grain Size Analysis, Atterberg Limits (plasticity characteristics), maximum density (Modified
Proctor) and Chemical Characteristics. Test descriptions and laboratory test results are included in
Appendix C.
4.0 GEOLOGY
4.1 General Setting
Carlsbad is located with the Peninsular Ranges physiographic province that is characterized by
northwest-trending mountain ranges, intervening valleys, and predominantly northwest trending
active regional faults. The 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. The coastal plain sub-province ranges in elevation from approximately
sea level to 1200 feet above mean sea level (msl) and is characterized by Cretaceous and Tertiary
sedimentary deposits that onlap an eroded basement surface consisting of Jurassic and Cretaceous
crystalline rocks that have been repeatedly eroded and infilled and by alluvial processes throughout
the Quaternary Period in response to regional uplift. This has resulted in a geomorphic landscape of
uplifted alluvial and marine terraces that are dissected by current active alluvial drainages.
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4.2 Geologic Conditions
Based on the regional geologic map prepared by Kennedy and Tan (2007), the near surface geologic
unit that underlies the site consists of Quaternary Alluvial Flood Plain Deposits. Based on recent
and previous site explorations, Quaternary Previously Placed Fill Soils overlie the Alluvial Deposits.
Tertiary Santiago Formation comprises the underlying geologic unit. Descriptions of the geologic
and soil units encountered during the investigations are presented below.
4.2.1 Quaternary Previously Placed Fill
Based on the exploratory borings, Previously Placed Fill generally consists of loose to
medium dense, moist to saturated clayey sands. Exploratory excavations encountered
Previously Placed Fill to a maximum observed depth of approximately 15 feet bgs.
Localized areas with deeper fill may be encountered during site excavations and
construction.
4.2.2 Quaternary Alluvial Flood Plain Deposits
Quaternary Alluvial Flood Plain Deposits associated within the partially infilled lagoon,
were observed beneath the fill in the previous exploratory borings. Where observed, these
materials were described as very soft to very loose clayey and silty soils with sandy lenses.
These soils were found to be saturated and were encountered to an approximate depth of 49
feet bgs.
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4.2.3 Tertiary Santiago Formation
Tertiary Santiago Formation, (map Tsa of Kennedy and Tan, 2007) was encountered beneath
the alluvial deposits in the previous exploratory borings at an approximate depth of 49 feet
bgs. The formational unit was described as olive fine sandy to clayey siltstone that is moist
and cemented. This unit is anticipated at depth throughout the site.
4.3 Groundwater Conditions
Groundwater was encountered in the exploratory excavations at an approximate depth of five to
seven feet bgs during the subsurface investigation. Groundwater conditions are anticipated to vary
based on factors including tidal fluctuation, precipitation, or irrigation, and may impact construction
activities. Proper site drainage should be designed, constructed, and maintained in accordance with
the recommendations of the project civil engineer. It is anticipated that foundation excavations will
encounter groundwater, based on the depths noted above, and appropriate installation operations will
be required based on foundation type and installation methods used.
4.4 Geologic Hazards
Geologic hazards considered to have potential impacts to site development were evaluated based on
field observations, literature review, and laboratory test results. The following paragraphs discuss
geologic hazards considered and associated potential risk to the site.
4.3.1 Surface Fault Rupture
In accordance with the State of California Alquist-Priolo Earthquake Fault Zoning Act,
(ACT), the State of California established Earthquake Fault Zones around known active
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faults. The purpose of the ACT is to regulate the development of structures intended for
human occupancy near active fault traces in order to mitigate hazards associated with surface
fault rupture. According to the California Geological Survey (Special Publication 42,
Revised 2018), a fault that has had surface displacement within the last 11,700 years is
defined as a Holocene-active fault and is either already zoned or is pending zonation in
accordance with the ACT. There are several other definitions of fault activity that are used
to regulate dams, power plants, and other critical facilities, and some agencies designate
faults that are documented as older that Holocene (last 11,700 years) and younger than late
Quaternary (1.6 million years) as potentially active faults that are subject to local
jurisdictional regulations.
Based on site reconnaissance and review of referenced literature, the site is not located
within a State designated Earthquake Fault Zone, no known active fault traces underlie or
project toward the site, and no known potentially active fault traces project toward the site.
4.3.2 Local and Regional Faulting
The United States Geological Survey (USGS), with support of State Geological Surveys, and
reviewed published work by various researchers, have developed a Quaternary Fault and
Fold Database of faults and associated folds that are believed to be sources of earthquakes
with magnitudes greater than 6.0 that have occurred during the Quaternary (the past 1.6
million years). The faults and folds within the database have been categorized into four
Classes (Class A-D) based on the level of evidence confirming that a Quaternary fault is of
tectonic origin, whether the structure is exposed for mapping or is inferred from fault related
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deformational features. Class A faults have been mapped and categorized based on age of
documented activity ranging from Historical faults (activity within last 150 years), Latest
Quaternary faults (activity within last 15,000 years), Late Quaternary (activity within last
130,000 years), to Middle to late Quaternary (activity within last 1.6 million years). The
Class A faults are considered to have the highest potential to generate earthquakes and/or
surface rupture, and the earthquakes and surface rupture potential generally increases from
oldest to youngest. The evidence for Quaternary deformation and/or tectonic activity
progressively decreases for Class B and Class C faults. When geologic evidence indicates
that a fault is not of tectonic origin it is considered to be a Class D structure. Such evidence
includes joints, fractures, landslides, or erosional of fluvial scarps that resemble fault scarps,
but demonstrate a non-tectonic origin.
The nearest known Class A fault is the Newport-Inglewood Fault (<15,000 years), which is
approximately 4.0 kilometers southwest of the site. The attached Figure 3 shows regional
faults and seismicity with respect to the site.
4.3.3 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.
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Based on the noted conditions, the site is located within a susceptible liquefaction zone and a
quantitative evaluation of liquefaction and seismic settlement was performed as summarized
herein. Input parameters for the liquefaction evaluation were based on the Maximum
Considered Earthquake (MCE, 2% probability of exceedance with a 50-year period). A
code-based acceleration value (PGAM) was obtained in accordance with ASCE 7-16
Equation 11.8-1. In order to quantify site liquefaction susceptibility, the computer program
CLiq was utilized. Five different methods for calculating potential dynamic settlement were
utilized when evaluating liquefaction induced settlement. Overall settlement results for all
five methods are presented in graphical format in Appendix E, “Overall Parametric
Assessment Method” graph. Based on subsurface conditions and proposed improvements,
CTE has determined that Robertson (2009) method is most appropriate and representative
evaluation for the potential settlement. The following data were utilized used for the
analysis:
Based on direct measurement during the recent subsurface exploration, groundwater was
encountered at a depth of approximately 6 feet bgs. Given the available information, a
conservative groundwater depth of two (2) feet bgs was modeled for the liquefaction
analysis.
As indicated, the PGAM value (0.59) obtained using ASCE 7-16 Section 11.8.3 was used
for the liquefaction evaluation.
Based on the area tectonic framework and probable seismic hazard deaggregation for
PGA, a modal contributing magnitude of 6.9 was used for the analysis.
A deep exploration was analyzed using the PGA and magnitude values obtained. The
conservative results of the evaluation based on Robertson 2009 method indicate that
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potential total and differential dynamic settlement at the site is anticipated to be on the order
of 6.4 inches and 3.7 inches, respectively. Based on the noted site conditions, it is
recommended herein that the proposed improvements be constructed on a completely rigid
mat foundation on properly prepared subgrade, or upon deep foundations that extend through
the liquefiable soils to underlying formational material.
Surface effects associated with liquefaction-related settlement can consist of sand boils, soil
strength loss, and associated phenomena. In general, the potential for surface manifestations
is related to the continuity and thickness of liquefiable layers compared to depth of overlying
non-liquefiable material (Ishihara, 1985). Based on the depth and distribution of the
potential liquefiable layers, significant surface effects may occur. Graphical analysis of
liquefaction induced ground settlement is presented in Liquefaction Analysis Summary Plots
presented in Appendix E.
The potential hazard associated with lateral spreading was calculated to be on the order of
one to two meters, which is considered to be significant. As a result, a completely rigid mat
foundation on properly prepared subgrade, or deep foundations are recommended for
building support.
Due to the nature of the proposed improvements, mitigation of the regional liquefaction
and/or seismic settlement potential is anticipated to be required. In addition to the
anticipated static settlement, structural design should accommodate the total and differential
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dynamic settlements post site preparation/deep foundation installation. The liquefaction
evaluation results are provided in Appendix E.
4.3.4 Tsunamis and Seiche Evaluation
According to the “Tsunami Inundation Map for Emergency Planning, Oceanside
Quadrangle/San Luis Rey Quadrangle Quadrangle”, provided by California Emergency
Management Agency and CGS, the site is located in or directly adjacent to a potential
tsunami inundation zone based on proximity to the coastline and elevation above sea level.
Based on the Tsunami Inundation Map references, the subject site lies adjacent to or within
the project tsunami inundation area, and may have the potential to be impacted by tsunami
run up in a rare event. The potential tsunami risks are anticipated to be similar to the
adjacent properties at similar elevations. In addition, the potential for oscillatory waves
(seiches) cannot be entirely precluded based on the proximity to the semi-confined lagoon
extension
4.3.5 Landsliding
According to mapping by Tan (1995), the site is considered to be only “Marginally
Susceptible” to landsliding, and no landslides are mapped in the site area. In addition,
evidence of landslides or landslide potential was not observed during the field exploration at
the relatively flat-lying site. Based on these findings, landsliding is not considered to be a
significant geologic hazard at the subject site.
4.3.6 Compressible and Expansive Soils
The Previously Placed Fill and Alluvial Deposits are considered to be compressible in their
current condition. Therefore, it is recommended that these soils be overexcavated beneath
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proposed surface improvements such as slabs and flatwork, where necessary, and properly
compacted as recommended herein and as determined to be necessary during construction. It
is anticipated that proposed structural improvements will be founded on deep foundations
extended to the depth of competent native materials as recommended herein.
Based on laboratory testing and plastic nature of the subgrade materials, soils at the site are
anticipated to exhibit medium to high expansion potential (Expansion Index of greater than
90). Therefore, expansive soils are generally anticipated to present significant adverse
impacts to site development if geotechnical recommendations are not properly implemented.
Additional evaluation of near-surface soils should be performed based on field observations
during grading and excavation activities.
4.3.7 Corrosive Soils
Testing of representative site soils was performed to evaluate the potential corrosive effects
on concrete foundations and 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 the 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
0.10 percent by weight. These guidelines include low water:cement ratios, increased
compressive strength, and specific cement type requirements. 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 for buried metallic utilities and untreated
conduits.
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Chemical test results indicate that near-surface soils at the site generally present a moderate
corrosion potential for Portland cement concrete. This condition requires minimum design
strength of 3,500 psi and a maximum water cement ratio of 0.40. Based on resistivity and
chloride testing, the site soils have been interpreted to have an extreme corrosivity potential
to buried metallic improvements.
Based on the results of the limited testing performed, it is likely prudent to utilize plastic
piping and conduits where buried and feasible. However, CTE does not practice corrosion or
cathodic protection engineering. Therefore, if corrosion of metallic or other improvements is
of more significant concern, a qualified corrosion engineer could be consulted.
5.0 CONCLUSIONS AND RECOMMENDATIONS
5.1 General
CTE concludes that the proposed improvements on the site are feasible from a geotechnical
standpoint, provided the preliminary 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 conflicts exist. These preliminary
recommendations should either be confirmed as appropriate or updated following required
excavations, demolition of existing improvements, and observations during site preparation.
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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 order to provide more uniform slab
support, subgrade beneath proposed slab on grade areas should be excavated a minimum of 18
inches or to the depth of suitable material, whichever is greater. Exposed areas should then be
scarified and recompacted as described herein. If mat slab site preparation recommendations are
completed, additional specific slab on grade excavation will generally not be necessary.
Recommendations are provided for the option of founding the structure on mat foundations. As
indicated the site is underlain by loose soils with shallow groundwater and adjacent structures are
within close proximity. Therefore, the overexcavation and recompaction required for mat support
may require dewatering, shoring and specialized techniques. In addition, structures founded on mat
slab foundations will be subject to differential settlement potential on the order of 3.7 inches over a
horizontal distance of 40 feet. Based on the anticipated significant issues associated with mat slab
construction, recommendations have also been provided for support of the proposed structure on
deep auger cast or torque-in piles, which are generally preferable foundation systems given the site
conditions.
For the use of mat foundations, and based on the presence of soft, loose, disturbed and potentially
compressible near surface soils, overexcavation in the areas to receive structural improvements
should be conducted to a minimum depth of 10 feet below bottom of existing or proposed ground
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surface, a minimum eight feet below bottom of mat foundations, or to the depth of competent and
suitable native material, whichever is greatest. Overexcavation should extend at least eight feet
laterally beyond the limits of the proposed improvements, where feasible. Should lateral
overexcavation not be feasible due to existing improvements, the use of geosynthetic reinforcing
grid is recommended as described in section 5.7.2.1.
Suitability of the bottom of all overexcavations and footing excavations should be verified by a CTE
geotechnical representative during site grading. If localized areas of loose or unsuitable materials
are encountered at the base of the recommended excavations, deeper removals to the depth of
competent soil may be necessary.
For other proposed improvements, such as pavement and hardscape areas, existing soils should be
excavated to the depth of competent materials, or to a minimum of two feet below existing grade,
whichever depth is greater.
Exposed subgrades should be scarified, moisture conditioned, and properly compacted, as described
below, prior to receiving compacted fill.
Overexcavations adjacent to existing structures should generally not extend below a 1:1 plane
extended down from the bottom of the existing footings or as recommended during grading based on
the exposed conditions. Depending on the depth and proximity of the existing building footings to
remain, alternating slot excavations and shoring could be required during earthwork.
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Existing below-ground utilities should be redirected around the proposed structures. Existing
utilities at an elevation to extend through the proposed footings should generally be sleeved and
caulked to minimize the potential for moisture migration below the building slabs. Abandoned pipes
exposed by grading should be securely capped or filled with minimum two-sack cement/sand slurry
to help prevent moisture from migrating beneath foundation and slab soils.
5.3 Site Excavation
Based on CTE’s observations, shallow excavations at the site should be feasible using well-
maintained heavy-duty construction equipment run by experienced operators. Excavations will also
likely encounter zones that are sensitive to caving and/or erosion, and may not effectively remain
standing vertical or near-vertical, even at shallow or minor heights and for short periods of time.
Based on the noted site conditions, it is also anticipated that significant groundwater seepage and
intrusion could impact site excavations, which may require specialized techniques or dewatering.
5.4 Fill Placement and Compaction
Following the recommended overexcavation of loose or disturbed soils, areas to receive fills should
be scarified approximately eight inches, moisture conditioned, and properly compacted. Fill and
backfill should be compacted to a minimum relative compaction of 90 percent at above optimum
moisture content, as evaluated by ASTM D 1557. Should fill soils be classified as clay and/or
expansive, soil should be compacted at a minimum three percent above optimum moisture. The
optimum lift thickness for fill soil depends on the type of compaction equipment used. Generally,
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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, and
should be observed and tested by a CTE geotechnical representative.
5.5 Fill Materials
Properly moisture conditioned, low expansion potential soils derived from the on-site materials are
considered suitable for reuse on the site as compacted fill. However, due to onsite soils exhibiting
medium to high expansion potential, care should be taken to ensure adequate moisture and blending
of material is achieved prior to compaction. 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 not be used in shallow fills (within three
feet of proposed grades). In utility trenches, adequate bedding should surround pipes.
Imported fill beneath structures and flatwork should have an Expansion Index of 20 or less (ASTM
D 4829). Imported fill soils for use in structural or slope areas should be evaluated by the soils
engineer before being imported to the site.
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If retaining walls are proposed, backfill located within a 45-degree wedge extending up from the
bottom of the heel foundation 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 should 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 drain zones, fills, filter fabric and perforated drain pipes. A conceptual
wall drainage detail is provided in 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 C soils with recommended slope
ratios as set forth in Table 5.6.
TABLE 5.6
RECOMMENDED TEMPORARY SLOPE RATIOS
SOIL TYPE SLOPE RATIO
(Horizontal: vertical) MAXIMUM HEIGHT
C (Previously Placed Fill) 1.5:1 (OR FLATTER) 5 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 Foundation and Slab Recommendations
Based on the reported site conditions, CTE anticipates it will be necessary to support the proposed
buildings and settlement sensitive structural improvements entirely on the underlying formation
materials via deep foundations, or upon a rigid mat foundation above properly prepared subgrade
sufficient to stabilize the underlying materials. As such, CTE anticipates it will be necessary to
either 1) utilize deep auger-cast pile or torque-in style foundations beneath structural improvements,
or 2) utilize a rigid mat foundation on properly prepared subgrade for ground modification.
Therefore, CTE has provided preliminary design parameters for rigid mat foundations and deep
foundations for preliminary design.
It may generally be considered suitable to support minor isolated or completely detached structures
(such as minor site walls, stairwells, stair stringers, stair landings, light posts, etc.) with independent
footings or foundations designed using lower geotechnical design parameters; however, the design of
these improvements, if proposed, should utilize the minimum design parameters allowed by the 2019
CBC.
5.7.1 Auger Cast or Torque-In Style and Grade Beam Foundation Systems
CTE has provided preliminary design recommendations for auger cast piles or torque-in style
piles and grade beam foundation system that may be used to support proposed
improvements. The design parameters presented herein are developed in an attempt to
minimize differential settlements.
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As stated, pile foundations are anticipated to be suitable for support of the proposed building
areas at the subject site. Piles should be designed and installed a qualified design/build
engineering contractor. However, we anticipate that minimum 6-inch diameter torque-in
style piles (with multiple minimum 12-inch end bearing flights) and minimum 16 inch
diameter for auger-cast pile extending to a depth on the order of 70 feet or practical refusal as
determined by the geotechnical engineer of record will develop minimum allowable
downward capacities on the order of 100 kips depending on type and size of pile installed
(based on a minimum factor of safety of 2.0). CTE can verify pile capacities one design
contractor has completed a preliminary pile design. It should be noted that due to required
lateral capacity, smaller diameter torque-in style piles may require additional tie-back style
support systems to be designed by the design/build contractor.
A pile and grade beam foundation system would include the installation of steel cased or
reinforced concrete piles at various locations beneath the proposed improvements. A
reinforced concrete grade beam should generally span between piles to provide additional
support. However, where loads will be entirely supported by the piles, the necessity for
grade beams should be determined by the structural engineer.
5.7.1.1 Pile Size, Embedment Depth, and Spacing
Piles should be embedded at least 70 feet (as stated above) and three feet into
competent underlying formational materials. Piles should also be spaced a minimum
of three diameters, center to center, to avoid group effects. Minimum pile
dimensions are as follows:
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Torque-in style piles – 6-inch diameter (minimum 12-inch flights)
Auger Pressure Grouted Piles – 16 inch diameter
Other pile types may be utilized upon review by CTE. Additionally, pile capacities
for proprietary style system should be verified by the specific design build pile
contactor. Proposed piles types and dimensions should be reviewed and approved by
CTE prior to installation.
5.7.1.2 Pile Vertical Bearing
Approved piles embedded at least three feet into competent underlying formational
materials are considered suitable for support of proposed improvements. Design of
piles, grade beams, and the structural concrete slab reinforcement should be provided
by the project structural engineer.
5.7.1.3 Grade Beams
Grade beams may be installed to distribute structure loads or resist lateral loads as
necessary. Grade beam reinforcement should be designed as per the structural
engineer. Grade beams may not be depended upon for vertical bearing. Lateral
resistance of grade beams may be designed or evaluated using the design parameters
provided for typical shallow spread foundations.
5.7.1.4 Lateral Resistance For Auger Cast In Place Piles
An equivalent passive fluid weight of 200 pounds per square foot per foot of depth,
up to a maximum pressure of 1,200 psf could be used for a generalized evaluation of
resistance to design lateral loads. This value assumes a horizontal surface for the soil
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mass extending at least 10 feet. After preliminary design is finalized, CTE should
perform LPile evaluation for proposed pile foundations once preliminary sizes are
determined and design lateral loads are developed.
5.7.1.5 Foundation Settlement
Minimum reinforcement for all footings should be as per the project structural
engineer. Should properly designed deep foundations be installed, the maximum
total static settlement is expected to be on the order of 1.0 inches and the maximum
differential settlement is expected to be on the order of 0.5 inches of a horizontal
distance of 40 feet. Dynamic structure settlements are anticipated to be on the order
of 1.0 inches total and 0.5 inches differential following proper deep foundation
installation.
5.7.2 Spread or Mat Foundations Supported On Geosynthetic Reinforced Raft
A mat foundation or continuous and isolated spread footings interconnected with grade
beams to act as a single rigid foundation are considered suitable for use at this site where
they will be underlain entirely upon a geosynthetic reinforced raft foundation properly
designed and installed by a qualified design/build specialist. Such foundation dimensions
and reinforcement can likely be based on an allowable bearing pressure of 1,250 pounds per
square foot (psf), or higher, depending on the specific design/build system utilized; however,
the bottoms of geosynthetic reinforced raft supported foundations should still be embedded a
minimum of 24 inches below the shallowest adjacent grade for continuous and isolated
spread footings or 18 inches below shallowest adjacent grade for mat foundations.
Foundation reinforcement for all footings should be as per the project structural engineer.
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Minimum reinforcement for continuous footings should consist of four No. 6 reinforcing
bars; two placed near the top and two placed near the bottom or as per the project structural
engineer. The recommended allowable bearing values may also generally be increased by
one third for short duration loading which includes the effects of wind or seismic forces. If
elastic design is utilized, a subgrade modulus should be determined by the specialty
design/build contractor. However, an uncorrected subgrade modulus of 90 pci may be used
for preliminary design prior to final determination by the specialty contractor. CTE can
provide final uncorrected subgrade modulus after completion of the reinforced raft, upon
request.
Detailed plans and specifications for any proposed geosynthetic reinforced raft system
should be developed by the specialty design/build contractor. The plans/specifications may
detail verification and/or load testing during construction to assure the system provided
adequate results; however, depending on the system installed, verification may not be
necessary upon approved from the governing authority. CTE should be provided the plans
for review prior to construction. CTE should also observe all installations and verification
testing, should testing be necessary. Compaction testing as defined in previous sections
should be incorporated during all fill placement and compaction during the installation of a
geosynthetic reinforced raft foundation.
After the geosynthetic reinforced raft foundation has been installed, additional
overexcavation is not deemed necessary due to observation and testing of fill placement and
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compaction as part of the raft installation. Preliminary recommendations for the raft
installation as detailed below will require excavation of onsite material. Should loose or
otherwise unsuitable soils be encountered at the base of excavation, additional removals to
the depth of competent material may be recommended, but are generally not anticipated.
Should the geosynthetic option be used, overexcavation should extend at least three feet
laterally beyond the proposed building limits, or to a distance equal to the depth of the
overexcavation, where feasible.
5.7.2.1 Geosynthetic Grid Type, Depth, and Spacing
These recommendations are preliminary and should be modified by the manufacturer
or installation professional. CTE anticipates, at a minimum, three layers of bi- or tri-
axial geosynthetic soil stabilization grid should be placed below the proposed
building foundations. Geosynthetic grid should extend a minimum three feet outside
the structural footprint, or as specified by the geosynthetic material manufacturer.
The upper layer of geosynthetic grid should be placed between two and four feet
below the bottom of proposed footings. The second from the top layer should be
located approximately 10 to 18 inches below the upper layer. The third and likely
bottom layer should be placed with approximate vertical spacing of 10 to 18 inches
below the second layer. The lowest layer should be placed on subgrade soil
compacted to the highest feasible degree. Excavation should take place to a
minimum depth of 10 feet below existing grade and is may require shoring and
dewatering based on site conditions and proximity of adjacent structures. Should
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excessive pumping be observed prior to placement of fill and/or geosynthetic grid, a
bridging layer of crushed aggregate may be used as a base for compaction.
5.7.2.2 Foundation Settlement
Should a properly designed reinforced raft be installed, the maximum total static
settlement is expected to be on the order of 2.0 inches and the maximum differential
settlement is expected to be on the order of 1.0 inches over a horizontal distance of
40 feet. Dynamically induced settlement due to liquefaction is discussed in section
4.3.3 of this report.
Based on the investigation findings and settlement analysis, flexible utility
connections should be designed and installed to withstand the anticipated settlements
without rupture or significant distress.
5.7.2.3 Lateral Load Resistance
The following recommendations may be used for shallow footings and mat
foundation on the site. Foundations placed in engineered fill materials may be
designed using a coefficient of friction of 0.25 (total frictional resistance equals the
coefficient of friction times the dead load).
A design passive resistance value of 200 pounds per square foot per foot of depth
(with a maximum value of 1,200 pounds per square foot) may be used. The
allowable lateral resistance can be taken as the sum of the frictional resistance and
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the passive resistance, provided the passive resistance does not exceed two-thirds of
the total allowable resistance.
5.7.2.4 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 15 feet. In addition,
footings should bear beneath an imaginary 1:1 plane extended up from the nearest
bottom edge of adjacent trenches and/or excavations. Footings may generally be
deepened in order to meet this recommendation.
5.7.4 Interior Concrete Slabs
Lightly loaded non-structural interior concrete slabs for non-traffic areas should be a
minimum of 5.0 inches thick, or slabs should be designed to match existing thickness at
building modification boundaries per recommendations of the project structural engineer.
Minimum reinforcement for lightly loaded slabs should consist of #4 reinforcing bars placed
on maximum 16-inch centers, each way, at or above mid-slab height, but with proper cover
or as per the recommendations of the project structural engineer. This slab on grade should
be considered sacrificial in the event of significant liquefaction settlement. The designer of
record may elect to design and install a post tension slab on grade to help avoid significant
distress associated with the potential seismic settlement.
In moisture-sensitive non-traffic 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 aggregate base or gravel (with SE of 30 or more) should be installed. An
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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.
Slabs subjected to heavier loads and traffic will require thicker slab sections and/or increased
reinforcement. A 90-pci subgrade modulus is considered suitable for elastic design of
minimally embedded improvements such as slabs-on-grade.
Subgrade materials should be maintained at a minimum of two percent above optimum
moisture content until slab underlayment and concrete are placed.
5.8 Seismic Design Criteria
The seismic ground motion values listed in the table below were derived in accordance with the
ASCE 7-16 Standard. This was accomplished by establishing the Site Class based on the soil
properties at the site, and calculating the site coefficients and parameters using the United States
Geological Survey Seismic Design Maps application. These values are intended for the design of
structures to resist the effects of earthquake ground motions for the site coordinates 33.1457° latitude
and –117.3245° longitude, as underlain by soils corresponding to site Class D.
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TABLE 5.8
SEISMIC GROUND MOTION VALUES (CODE-BASED)
2019 CBC AND ASCE 7-16
PARAMETER VALUE 2019 CBC/ASCE 7-16
REFERENCE
Site Class E ASCE 16, Chapter 20
Mapped Spectral Response
Acceleration Parameter, SS 1.050g Figure 1613.2.1 (1)
Mapped Spectral Response
Acceleration Parameter, S1 0.380g Figure 1613.2.1 (2)
Seismic Coefficient, Fa null Table 1613.2.3 (1)
Seismic Coefficient, Fv null Table 1613.2.3 (2)
MCE Spectral Response
Acceleration Parameter, SMS null Section 1613.2.3
MCE Spectral Response
Acceleration Parameter, SM1 null Section 1613.2.3
Design Spectral Response
Acceleration, Parameter SDS null Section 1613.2.5(1)
Design Spectral Response
Acceleration, Parameter SD1 null Section 1613.2.5 (2)
Peak Ground Acceleration PGAM 0.589g ASCE 16, Section 11.8.3
It is anticipated that the project will meet the requirements provided in ASCE 11.4.8, Exception 3, provided T < Ts and
the equivalent static force procedure is used for design.
5.9 Lateral Resistance and Earth Pressures
Lateral loads acting against structures may be resisted by friction between the footings and the
supporting soil or passive pressure acting against structures. If frictional resistance is used,
allowable coefficients of friction of 0.25 (total frictional resistance equals the coefficient of friction
multiplied by the dead load) for concrete cast directly against compacted fill or native material is
recommended. A design passive resistance value of 200 pounds per square foot per foot of depth
(with a maximum value of 1,200 pounds per square foot) may be used. The allowable lateral
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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 backfilled using granular soils may be designed using the equivalent
fluid unit weights given in Table 5.9 below.
Lateral pressures on cantilever retaining walls (yielding walls) over six feet high due to
earthquake motions may be calculated based on work by Seed and Whitman (1970). The total
lateral earth pressure 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 earth pressure may be similarly
calculated based on work by Wood (1973):
PKE = PK + ΔPKE
Where PA/b = Static Active Earth Pressure = GhH2/2
TABLE 5.9
EQUIVALENT FLUID UNIT WEIGHTS (Gh)
(pounds per cubic foot)
WALL TYPE LEVEL BACKFILL
SLOPE BACKFILL
2:1 (HORIZONTAL:
VERTICAL)
CANTILEVER WALL
(YIELDING) 60 85
RESTRAINED WALL 100 115
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PK/b = Static Restrained Wall Earth Pressure = GhH2/2
ΔPAE/b = Dynamic Active Earth Pressure Increment = (3/8) kh γH2/2
ΔPKE/b = Dynamic Restrained Earth Pressure Increment = kh γH2/2
b = unit length of wall
kh = 2/3 PGAm (PGAm given previously Table 5.8)
Gh = Equivalent Fluid Unit Weight (given previously Table 5.9)
H = Total Height of the retained soil
γ = Total Unit Weight of Soil ≈ 135 pounds per cubic foot
The static and increment of dynamic earth pressure in both cases may be applied 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. Waterproofing should be as specified by the project architect.
Design of temporary shoring may utilize the abovementioned values with a reduction of 25%
equivalent fluid pressure. CTE can evaluate the proposed temporary shoring plans as they are in the
design process to modify design values based on the type and construction methods used for the
shoring system.
5.10 Exterior Flatwork
Flatwork should be installed with crack-control joints at appropriate spacing as designed by the
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project architect to reduce the potential for cracking in exterior flatwork caused by minor movement
of subgrade soils and concrete shrinkage. Additionally, it is recommended that flatwork be installed
with at least number 4 reinforcing bars at 16-inch centers, each way, at or above mid-height of slab,
but with proper concrete cover, or with other reinforcement per the applicable project designer.
Flatwork that should be installed with crack control joints, includes driveways, sidewalks, and
architectural features. All 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 should be maintained at a minimum of two
percent above optimum moisture content until the time of concrete placement.
5.11 Vehicular Pavement
If proposed improvements include paved vehicle drive and parking areas the following
recommendations are provided. Presented in Table 5.11 are preliminary pavement sections utilizing
preliminary representative Resistance “R” Value. Actual drive area slab sections to be provided by
the structural designer. Beneath proposed pavement areas, the upper 12 inches of subgrade and all
base materials should be compacted to 95% relative compaction in accordance with ASTM D1557,
and at a minimum of two percent above optimum moisture content.
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TABLE 5.11
RECOMMENDED PAVEMENT THICKNESS
Traffic Area
Assumed
Traffic Index
Preliminary
Subgrade
“R”-Value
Asphalt Pavements
Portland Cement
Concrete
Pavements, on
Subgrade Soils
(inches)
AC
Thickness
(inches)
Class II
Aggregate Base
Thickness
(inches)
Drive Areas 5.5 5+ 4.0 10.0 7.5
Auto Parking
Areas 4.5 5+ 4.0 6.0 6.5
* Caltrans Class 2 aggregate base
** Concrete should have a modulus of rupture of at least 600 psi
Following rough site grading, CTE recommends laboratory testing of representative subgrade soils
for as-graded “R”-Value.
Asphalt paved areas should be designed, constructed, and maintained in accordance with 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 the proposed
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improvements. Positive drainage should be directed away from improvements at a gradient of at
least two percent for a distance of at least five feet. However, the project civil engineers 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.
CTE understands that some agencies are encouraging the use of storm-water cleansing devices. Use
of such devices tends to increase the possibility of adverse effects associated with high groundwater
including slope instability and liquefaction.
5.12 Slopes
Based on anticipated soil strength characteristics, if proposed, site slopes should be constructed at
ratios of 2:1 (horizontal: vertical) or flatter. These 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
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.
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5.13 Controlled Low Strength Materials (CLSM)
Controlled Low Strength Materials (CLSM) may be used in deepened footing excavation areas,
building pads, and/or adjacent to retaining walls or other structures, provided the appropriate
following recommendations are also incorporated. Minimum overexcavation depths recommended
herein beneath slabs, flatwork, and other areas may be applicable beneath CLSM if/where CLSM is
to be used, and excavation bottoms should be observed by CTE prior to placement of CLSM. Prior
to CLSM placement, the excavation should be free of debris, loose soil materials, and water. Once
specific areas to utilize CLSM have been determined, CTE should review the locations to determine
if additional recommendations are appropriate.
CLSM should consist of a minimum three-sack cement/sand slurry with a minimum 28-day
compressive strength of 100 psi (or equal to or greater than the maximum allowable short term soil
bearing pressure provided herein, whichever is higher) as determined by ASTM D4832. If re-
excavation is anticipated, the compressive strength of CLSM should generally be limited to a
maximum of 150 psi per ACI 229R-99. Where re-excavation is required, two-sack cement/sand
slurry may be used to help limit the compressive strength. The allowable soils bearing pressure and
coefficient of friction provided herein should still govern foundation design. CLSM may not be used
in lieu of structural concrete where required by the structural engineer.
5.14 Plan Review
CTE should be authorized to review the project grading and foundation plans prior to
commencement of earthwork in order to provide additional recommendations, if necessary.
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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 soil borings. The interpolated
subsurface conditions should be checked by CTE during construction with respect to anticipated
conditions. Upon completion of precise grading, if necessary, soil samples will be collected to
evaluate as-built Expansion Index. Foundation recommendations may be revised upon completion
of grading, and as-built laboratory tests results. Additionally, soil samples should be taken in
pavement subgrade areas upon rough grading to refine pavement recommendations as necessary.
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 in accordance with recommendations contained within this report. CTE should evaluate
footing excavations before reinforcing steel placement.
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
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during construction. This report is prepared for the project as described. It is not prepared for any
other property or party.
The recommendations provided herein have been developed in order to reduce the post-construction
movement of site improvements. However, even with the design and construction recommendations
presented herein, some post-construction movement and associated distress may occur.
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 CTE’s involvement.
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, CTE should be notified and
additional recommendations, if required, will be provided subject to CTE remaining as authorized
geotechnical consultant of record. This report is for use of the project as described. It should not be
utilized for any other project.
CTE appreciates this opportunity to be of service on this project. If you have any questions
regarding this report, please do not hesitate to contact the undersigned.
Geotechnical Investigation
Proposed Harle Residence
4547 Cove Drive, Carlsbad, California
February 26, 2021 CTE Job No. 10-15981G
S:\Projects\10-15000 to 10-15999 Projects\10-15981G\Geotechnical Report\Rpt_Geotechnical.doc
Page 36
Respectfully submitted,
CONSTRUCTION TESTING & ENGINEERING, INC.
Dan T. Math, GE #2665 Jay F. Lynch, CEG #1890
Principal Geotechnical Engineer Principal Engineering Geologist
Rodney J. Jones, RCE #84232
Senior Engineer
APPENDIX A
REFERENCES
REFERENCES
1. ASTM, 2002, “Test Method for Laboratory Compaction Characteristics of Soil Using
Modified Effort,” Volume 04.08
2. Blake, T.F., 2000, “EQFAULT,” Version 3.00b, Thomas F. Blake Computer Services and
Software.
3. California Building Code, 2019, “California Code of Regulations, Title 24, Part 2, Volume 2
of 2,” California Building Standards Commission, published by ICBO, June.
4. 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.
5. Hart, Earl W., Revised 1994, Revised 2018, “Fault-Rupture Hazard Zones in California,
Alquist Priolo, Special Studies Zones Act of 1972,” California Division of Mines and
Geology, Special Publication 42.
6. Jennings, Charles W., 1994, “Fault Activity Map of California and Adjacent Areas” with
Locations and Ages of Recent Volcanic Eruptions.
7. Kennedy, M.P. and Tan, S.S., 2007, “Geologic Map of the Oceanside 30’ x 60’ Quadrangle,
California”, California Geological Survey, Map No. 2.
8. McCulloch, D.S., 1985, “Evaluating Tsunami Potential” in Ziony, J.I., ed., Evaluating
Earthquake Hazards in the Los Angeles Region – An Earth-Science Perspective, U.S.
Geological Survey Professional Paper 1360.
9. Reichle, M., Bodin, P., and Brune, J., 1985, The June 1985 San Diego Bay Earthquake
swarm [abs.]: EOS, v. 66, no. 46, p.952.
10. 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.
11. SMS Geotechnical Solutions, Inc., 2016, “Geotechnical Update Report, Proposed Residential
Duplex Development, Existing Pad (Lot 31), 4547 Cove Drive, Carlsbad, California” Project
No. GI-16-06-128 dated July 25, 2016
12. 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.
13. United States Geological Services (USGS) Seismic Deaggregation Unified Hazard Tool,
2014 (Update) (v4.2.0) , https://earthquake.usgs.gov /hazards/interactive/
14. Vinje & Middleton Engineering, Inc., 2006. “Preliminary Geotechnical Investigation, Lot 31,
Tract 5162, Code Drive, Carlsbad, California” Job# 03-348-P dated March 3, 2004
15. Vinje & Middleton Engineering, Inc., 2006. “Foundation Plan Review, Proposed Three-
Story Twin Homes, Lot 31, Tract 5162, Code Drive, Carlsbad, California” Job# 03-348-P
dated July 14, 2006
16. Vinje & Middleton Engineering, Inc., 2006. “Update Geotechnical Report and Remedial
Grading Ground Stabilization Recommendations, Lot 31, Tract 5162, Code Drive, Carlsbad,
California” Job# 03-348-P dated September 25, 2006
17. Wood, J.H. 1973, Earthquake-Induced Soil Pressures on Structures, Report EERL 73-05.
Pasadena: California Institute of Technology.
APPENDIX B
EXPLORATION LOGS (CTE 2021)
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 IS
LESS THAN 50
SILTS AND CLAYS
LIQUID LIMIT IS
GREATER THAN 50
SANDS
MORE THAN
HALF OF
COARSE
FRACTION IS
SMALLER
THAN
GRAVELS
MORE THAN
HALF OFCOARSE
FRACTION IS
LARGER
THAN
CLEAN
GRAVELS
< 5% FINES
GRAVELS WITH FINES
CLEAN
SANDS
< 5% FINES
SANDSWITH FINESCOARSE GRAINED SOILSMORE THAN HALF OF MATERIAL IS LARGER THAN GP
GM
GC
SW
SP
SM
SC
ML
CL
OL
MH
CH
OH
PTFINE GRAINED SOILSMORE THAN HALF OF MATERIAL IS SMALLER HIGHLY ORGANIC SOILS
SILTS AND CLAYSCOBBLESCOBBLESBOULDERS
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
PROJECT:SHEET: of
CTE JOB NO: DRILL METHOD: DRILLING DATE:
LOGGED BY: SAMPLE METHOD: ELEVATION:Depth (Feet)Bulk SampleDriven TypeBlows/6"Dry Density (pcf)Moisture (%)U.S.C.S. SymbolGraphic LogDESCRIPTION
CL
CH
CL/SC
SP
1
10-15981G 3" HAND-AUGER 2/10/2021
HARLE RESIDENCE DRILLER: CTE, INC. 1
DJT BULK ~14'
BORING: HA-1 Laboratory Tests
Topsoil: 0-4" SP with GravelQUATERNARY PREVIOUSLY PLACED FILL:Soft to medium stiff, slightly moist, reddish-brown, fine to medium grained sandy CLAY.QUATERNARY YOUNG ALLUVIAL FLOODPLAIN DEPOSITVery soft to soft, slightly moist, grayish-brown fat CLAY, trace sand.
Becomes moist at 5'
Soft, wet, dark grayish brown, fine grained sandy CLAY to loose clayey SAND.
Loose to meidum dense, wet, grayish-brown, poorly gradedSAND, trace clay.
Total Depth: 10'Groundwater Encountered at 6'Backfilled with Bentonite
HA-1
0
5
10
15
20
25
PROJECT:SHEET: of
CTE JOB NO: DRILL METHOD: DRILLING DATE:
LOGGED BY: SAMPLE METHOD: ELEVATION:Depth (Feet)Bulk SampleDriven TypeBlows/6"Dry Density (pcf)Moisture (%)U.S.C.S. SymbolGraphic LogDESCRIPTION
SP
CL
SP
CL
HA-2
Backfilled with Bentonite
Total Depth: 10'No Groundwater Encountered
Medium stiff, moist, grayish-brown, fat CLAY, sand laminates.
graded SAND, trace roots.
QUATERNARY YOUNG ALLUVIAL FLOODPLAIN Medium dense, slgihtly moist, light reddish-brown, poorly
Medium stiff, slightly moist, grayish-brown, fine to medium grained sandy CLAY.
QUATERNARY PREVIOUSLY PLACED FILL:Loose, slightly moist, reddish-brown, poorly graded SAND.
DJT BULK ~12'
BORING: HA-2 Laboratory Tests
HARLE RESIDENCE DRILLER: CTE, INC. 1 1
10-15981G 3" HAND-AUGER 2/10/2021
0
5
10
15
20
25
Project:CTE / Harle Residence
Kehoe Testing and Engineering
714-901-7270
steve@kehoetesting.com
www.kehoetesting.com
Total depth: 79.49 ft, Date: 2/10/20214547 Cove Dr, Carlsbad, CA
CPT-1
Location:
Cone resistance
Tip resistance (tsf)
5004003002001000Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Cone resistance Sleeve friction
Friction (tsf)
876543210Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Sleeve friction Pore pressure u
Pressure (psi)
403020100-10-20Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Pore pressure u Friction ratio
Rf (%)
876543210Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Friction ratio Soil Behaviour Type
SBT (Robertson, 2010)
181614121086420Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Soil Behaviour Type
Sand & silty sand
Silty sand & sandy silt
Clay
Silty sand & sandy silt
Clay & silty clay
Clay & silty clay
Clay
Silty sand & sandy silt
Clay
Silty sand & sandy silt
Clay & silty clay
Clay
Clay & silty clay
Silty sand & sandy silt
ClayClay & silty clay
Sand & silty sand
Clay
Silty sand & sandy silt
Sand & silty sand
Clay & silty clay
Sand & silty sandClay
Clay & silty clay
Clay & silty clay
Clay & silty clay
Silty sand & sandy silt
Sand & silty sand
Clay
Clay & silty clay
Sand & silty sand
Silty sand & sandy silt
Clay
Sand & silty sand
Clay & silty clay
Silty sand & sandy silt
Very dense/stiff soil
Very dense/stiff soil
Very dense/stiff soil
Very dense/stiff soil
Very dense/stiff soil
CPeT-IT v.2.3.1.9 - CPTU data presentation & interpretation software - Report created on: 2/11/2021, 1:43:07 PM 1
Project file:
Project:CTE / Harle Residence
Kehoe Testing and Engineering
714-901-7270
steve@kehoetesting.com
www.kehoetesting.com
Total depth: 60.17 ft, Date: 2/10/20214547 Cove Dr, Carlsbad, CA
CPT-2
Location:
Cone resistance
Tip resistance (tsf)
5004003002001000Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Cone resistance Sleeve friction
Friction (tsf)
876543210Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Sleeve friction Pore pressure u
Pressure (psi)
403020100-10-20Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Pore pressure u Friction ratio
Rf (%)
876543210Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Friction ratio Soil Behaviour Type
SBT (Robertson, 2010)
181614121086420Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Soil Behaviour Type
Silty sand & sandy silt
Silty sand & sandy silt
Silty sand & sandy silt
Organic soil
Clay
Silty sand & sandy silt
Silty sand & sandy silt
Clay
Clay & silty clay
Clay
Clay & silty clay
Clay
Clay & silty clay
Clay & silty clay
Clay & silty clay
Silty sand & sandy siltSand & silty sand
Silty sand & sandy silt
Clay & silty clay
Clay
Clay
Clay & silty clay
Clay
Clay & silty clay
Clay & silty clayClay & silty clay
Clay
Very dense/stiff soil
Very dense/stiff soil
CPeT-IT v.2.3.1.9 - CPTU data presentation & interpretation software - Report created on: 2/11/2021, 1:43:56 PM 1
Project file:
Project:CTE / Harle Residence
Kehoe Testing and Engineering
714-901-7270
steve@kehoetesting.com
www.kehoetesting.com
Total depth: 60.38 ft, Date: 2/10/20214547 Cove Dr, Carlsbad, CA
CPT-3
Location:
Cone resistance
Tip resistance (tsf)
5004003002001000Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Cone resistance Sleeve friction
Friction (tsf)
876543210Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Sleeve friction Pore pressure u
Pressure (psi)
403020100-10-20Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Pore pressure u Friction ratio
Rf (%)
876543210Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Friction ratio Soil Behaviour Type
SBT (Robertson, 2010)
181614121086420Depth (ft)80
78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Soil Behaviour Type
Clay & silty clay
Clay
Clay
Clay
Silty sand & sandy silt
Sand & silty sand
Clay
Clay & silty clay
Clay
Clay & silty clay
Clay & silty clay
Clay & silty clay
Clay & silty clay
Clay
Clay & silty clay
Clay
Clay
Clay & silty clay
Clay
Clay & silty clay
Clay & silty clay
Very dense/stiff soil
Clay
Very dense/stiff soil
CPeT-IT v.2.3.1.9 - CPTU data presentation & interpretation software - Report created on: 2/11/2021, 1:44:14 PM 1
Project file:
APPENDIX B CONT’
EXPLORATION LOGS
VINJE & MIDDLETON BORING LOGS (2004)
APPENDIX C
LABORATORY METHODS AND RESULTS
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.
Expansion Index
Expansion testing was performed on selected samples of the matrix of the on-site soils according to
ASTM D 4829.
Particle-Size Analysis
Particle-size analyses were performed on selected representative samples according to ASTM D 422.
Atterberg Limits
The procedure of ASTM D4518-84 was used to measure the liquid limit, plastic limit and plasticity
index of representative samples.
Direct Shear
Direct shear tests were performed on either samples direct from the field or on samples recompacted
to a specific density. Direct shear testing was performed in accordance with ASTM D 3080. The
samples were inundated during shearing to represent adverse field conditions.
Chemical Analysis
Soil materials were collected with sterile sampling equipment and tested for Sulfate and Chloride
content, pH, Corrosivity, and Resistivity.
LOCATION EXPANSION INDEX EXPANSION
POTENTIAL
HA-1 95 HIGH
HA-1 80 MEDIUM
LOCATION RESULTS
ppm
HA-1 725.7
LOCATION RESULTS
ppm
HA-1 442.2
LOCATION RESULTS
HA-1 7.56
LOCATION RESULTS
ohms-cm
HA-1 509
LOCATION DEPTH LIQUID LIMIT PLASTICITY INDEX CLASSIFICATION
(feet)
HA-1 2-4 45 29 CL
HA-1 4-6 54 32 CH
LOCATION MAXIUM DRY DENSITY OPTIMUM MOISTURE
(PCF) (%)
HA-1 118.7 15
DEPTH
(feet)
0-2
EXPANSION INDEX TEST
ASTM D 4829
SULFATE
DEPTH
(feet)
0-5
CHLORIDE
DEPTH
(feet)
0-5
p.H.
DEPTH
(feet)
0-5
RESISTIVITY
CALIFORNIA TEST 424
DEPTH
ASTM D 1557
DEPTH
(feet)
0-5
2-4
(feet)
0-5
ATTERBERG LIMITS
MODIFIED PROCTOR
LABORATORY SUMMARY CTE JOB NO. 10-15948G
PARTICLE SIZE ANALYSISSample Designation Sample Depth (feet) Symbol Liquid Limit (%) Plasticity Index ClassificationHA-2 0-2' N/A N/A SCHA-2 2-4' N/A N/A SCCTE JOB NUMBER: 10-15981G FIGURE: C-101020304050607080901000.0010.010.1110100PERCENT PASSING (%)PARTICLE SIZE (mm)U. S. STANDARD SIEVE SIZE2"1"3/4"1/2"3/8"481016203040501002001.5"
SHEAR STRENGTH TEST - ASTM D3080
Job Name:
Project Number: 10-15981G
Lab Number: 31779
Sample Location: Tested by:
Sample Description:
JH
2/16/2021
Angle Of Friction: 32.7
Cohesion:
Harle Residence
200 psf
Initial Dry Density (pcf): 118.7
Initial Moisture (%): 15.0
Final Moisture (%): 24.4
HA-1 @ 0-5'
Sample Date:
Test Date:
2/10/2021
Light Gray (CL)
0.025
0.030
0.035
0.040
0.045
0.050
0.1 1 10 100STRAIN (inches)TIME (minutes)
PRECONSOLIDATION
0
1000
2000
3000
4000
5000
0 2 4 6 8 101214161820SHEAR STRESS (psf)STRAIN (%)
SHEARING DATA
0
1000
2000
3000
4000
5000
0 1000 2000 3000 4000 5000SHEARING STRESS (psf)VERTICAL STRESS (psf)
FAILURE ENVELOPE
dr=0.0800 mm./min
VERTICAL STRESS
1000 psf
3000 psf
5000 psf
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).
APPENDIX E
LIQUEFACTION EVALUATION
LIQUEFA CTION A NA L YS IS RE PORT
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
.
G.W.T. (in-situ):
G.W.T. (earthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Project title : CTE / Harle Residence Location : 4547 Cove Dr, Carlsbad, CA
Kehoe Testing and Engineering
714-901-7270
steve@kehoetesting.com
www.kehoetesting.com
CPT file : CPT-1
6.00 ft
2.00 ft
1
2.60
Based on SBT
Use fill:
Fill height:
Fill weight:
Trans. detect. applied:
Kσ applied:
No
N/A
N/A
Yes
No
Clay like behavior
applied:
Limit depth applied:
Limit depth:
MSF method:
All soils
No
N/A
Method based
Cone resistance
qt (tsf)
4002000Depth (ft)75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Cone resistance SBTn Plot
Ic (Robertson 1990)
4321
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
SBTn Plot CRR plot
CRR & CSR
0.60.40.20
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
CRR plot
During earthq.
Qtn,cs
200180160140120100806040200Cyclic Stress Ratio* (CSR*)0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Liquefaction
No Liquefaction
Normalized friction ratio (%)
0.1 1 10Normalized CPT penetration resistance1
10
100
1,000
Friction Ratio
Rf (%)
1086420
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Friction Ratio
Mw=71/2, sigma'=1 atm base curve Summary of liquefaction potential
FS Plot
Factor of safety
21.510.50
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
FS Plot
During earthq.
Zone A1: Cyclic liquefaction likely depending on size and duration of cyclic loading
Zone A2: Cyclic liquefaction and strength loss likely depending on loading and ground
geometry
Zone B: Liquefaction and post-earthquake strength loss unlikely, check cyclic softening
Zone C: Cyclic liquefaction and strength loss possible depending on soil plasticity,
brittleness/sensitivity, strain to peak undrained strength and ground geometry
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:41 PM
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
1
This software is licensed to: CTE, Inc.CPT name: CPT-1
Cone resistance
qt (tsf)
4002000Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Cone resistance
CPT ba s ic int e r pr e t a t io n plo t s
Friction Ratio
Rf (%)
1086420Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Friction Ratio Pore pressure
u (psi)
3020100-10Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Pore pressure
Insitu
SBT Plot
Ic(SBT)
4321Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBT Plot Soil Behaviour Type
SBT (Robertson et al. 1986)
1817161514131211109876543210Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
Soil Behaviour Type
Silty sand & sandy silt
Silty sand & sandy siltOrganic soilSilty sand & sandy siltClay & silty clayClay & silty clay
ClayClay & silty clayClaySilty sand & sandy siltClay
Clay
Clay & silty claySilty sand & sandy siltClay & silty claySilty sand & sandy siltSand & silty sandClay
Sand & silty sandSand & silty sandSilty sand & sandy siltSilty sand & sandy siltSilty sand & sandy siltSilty sand & sandy silt
ClayClay & silty claySilty sand & sandy siltSilty sand & sandy siltSilty sand & sandy silt
Sand & silty sand
Silty sand & sandy siltClaySand & silty sandClay & silty clay
Silty sand & sandy siltSand & silty sandSand & silty sandVery dense/stiff soilVery dense/stiff soilVery dense/stiff soilVery dense/stiff soil
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:41 PM 2
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
SBT legend
1. Sensitive fine grained
2. Organic material
3. Clay to silty clay
4. Clayey silt to silty
clay5. Silty sand to sandy silt
6. Clean sand to silty sand
7. Gravely sand to sand
8. Very stiff sand to
clayey sand9. Very stiff fine grained
This software is licensed to: CTE, Inc.CPT name: CPT-1
Norm. cone resistance
Qtn
200150100500Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. cone resistance
CP T ba s ic in t e r p r e t a t io n pl o t s ( no r ma l iz e d)
Norm. friction ratio
Fr (%)
1086420Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. friction ratio Nom. pore pressure ratio
Bq
10.80.60.40.20-0.2Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Nom. pore pressure ratio SBTn Plot
Ic (Robertson 1990)
4321Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBTn Plot Norm. Soil Behaviour Type
SBTn (Robertson 1990)
1817161514131211109876543210Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
Norm. Soil Behaviour Type
Sand & silty sandSand & silty sandClay
Silty sand & sandy siltSilty sand & sandy siltClay & silty clayClay & silty clay
Silty sand & sandy siltSilty sand & sandy siltSilty sand & sandy siltClay & silty clay
ClayClay & silty clay
Clay
Clay & silty claySilty sand & sandy siltClay & silty clayClay & silty claySand & silty sandClay
Sand & silty sandSand & silty sandSilty sand & sandy siltSilty sand & sandy siltClay & silty clay
Silty sand & sandy siltClayClay & silty clayClay & silty claySilty sand & sandy siltSilty sand & sandy silt
Sand & silty sand
Silty sand & sandy siltClaySand & silty sandClay & silty clayClaySilty sand & sandy siltSilty sand & sandy siltVery dense/stiff soil
Very dense/stiff soilVery dense/stiff soil
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:41 PM 3
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
SBTn legend
1. Sensitive fine grained
2. Organic material
3. Clay to silty clay
4. Clayey silt to silty
clay5. Silty sand to sandy silt
6. Clean sand to silty sand
7. Gravely sand to sand
8. Very stiff sand to
clayey sand9. Very stiff fine grained
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
This software is licensed to: CTE, Inc.CPT name: CPT-1
Total cone resistance
qt (tsf)
5004003002001000Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Total cone resistance
Liq ue f a c t io n a na l y s is o v e r a ll pl o t s ( int e r me di a t e r e s ult s )
SBTn Index
Ic (Robertson 1990)
4321Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBTn Index Norm. cone resistance
Qtn
200150100500Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. cone resistance Grain char. factor
Kc
109876543210Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Grain char. factor Corrected norm. cone resistance
Qtn,cs
200150100500Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Corrected norm. cone resistance
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:41 PM 4
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
This software is licensed to: CTE, Inc.CPT name: CPT-1
CRR plot
CRR & CSR
0.60.40.20Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
CRR plot
During earthq.
Li que f a c t i o n a na ly s is o v e r a l l p lo t s
FS Plot
Factor of safety
21.510.50Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
FS Plot
During earthq.
Liquefaction potential
LPI
20151050Depth (ft)64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Liquefaction potential Vertical settlements
Settlement (in)
6543210Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Vertical settlements Lateral displacements
Displacement (in)
806040200Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Lateral displacements
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:41 PM 5
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
F.S. color scheme LPI color schemeInput parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
Almost certain it will liquefy
Very likely to liquefy
Liquefaction and no liq. are equally likely
Unlike to liquefy
Almost certain it will not liquefy
Very high risk
High risk
Low risk
This software is licensed to: CTE, Inc.CPT name: CPT-1
Normalized friction ratio (%)
0.1 1 10Normalized CPT penetration resistance1
10
100
1,000
Li que f a c t i o n a n a ly s is s umma r y p lo t s
Qtn,cs
200180160140120100806040200Cyclic Stress Ratio* (CSR*)0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Liquefaction
No Liquefaction
Thickness of surface layer, H1 (m)
109876543210Thickness of liquefiable sand layer, H2 (m)12.0
11.0
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
CPT-1 (28.00)
Analysis PGA: 0.59
PGA 0.40g - 0.50gCLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:41 PM 6
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
This software is licensed to: CTE, Inc.CPT name: CPT-1
Norm. cone resistance
Qtn
25020015010050Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. cone resistance
Che c k f o r s t r e n gt h lo s s plo t s ( Ro be r t s o n ( 201 0) )
Grain char. factor
Kc
109876543210Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Grain char. factor Corrected norm. cone resistance
Qtn,cs
200150100500Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Corrected norm. cone resistance SBTn Index
Ic (Robertson 1990)
4321Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBTn Index Liquefied Su/Sig'v
Su/Sig'v
0.50.40.30.20.10Depth (ft)78
76
74
72
70
68
66
64
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
Peak Su ratio Liq. Su ratio
Liquefied Su/Sig'v
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:41 PM 7
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
LIQUEFA CTION A NA L YS IS RE PORT
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
.
G.W.T. (in-situ):
G.W.T. (earthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Project title : CTE / Harle Residence Location : 4547 Cove Dr, Carlsbad, CA
Kehoe Testing and Engineering
714-901-7270
steve@kehoetesting.com
www.kehoetesting.com
CPT file : CPT-2
6.00 ft
2.00 ft
1
2.60
Based on SBT
Use fill:
Fill height:
Fill weight:
Trans. detect. applied:
Kσ applied:
No
N/A
N/A
Yes
No
Clay like behavior
applied:
Limit depth applied:
Limit depth:
MSF method:
All soils
No
N/A
Method based
Cone resistance
qt (tsf)
4002000Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Cone resistance SBTn Plot
Ic (Robertson 1990)
4321
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBTn Plot CRR plot
CRR & CSR
0.60.40.20
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
CRR plot
During earthq.
Qtn,cs
200180160140120100806040200Cyclic Stress Ratio* (CSR*)0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Liquefaction
No Liquefaction
Normalized friction ratio (%)
0.1 1 10Normalized CPT penetration resistance1
10
100
1,000
Friction Ratio
Rf (%)
1086420
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Friction Ratio
Mw=71/2, sigma'=1 atm base curve Summary of liquefaction potential
FS Plot
Factor of safety
21.510.50
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
FS Plot
During earthq.
Zone A1: Cyclic liquefaction likely depending on size and duration of cyclic loading
Zone A2: Cyclic liquefaction and strength loss likely depending on loading and ground
geometry
Zone B: Liquefaction and post-earthquake strength loss unlikely, check cyclic softening
Zone C: Cyclic liquefaction and strength loss possible depending on soil plasticity,
brittleness/sensitivity, strain to peak undrained strength and ground geometry
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
8
This software is licensed to: CTE, Inc.CPT name: CPT-2
Cone resistance
qt (tsf)
4002000Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Cone resistance
CPT ba s ic int e r pr e t a t io n plo t s
Friction Ratio
Rf (%)
1086420Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Friction Ratio Pore pressure
u (psi)
20151050Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Pore pressure
Insitu
SBT Plot
Ic(SBT)
4321Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBT Plot Soil Behaviour Type
SBT (Robertson et al. 1986)
1817161514131211109876543210Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Soil Behaviour Type
Clay & silty clayClay & silty clay
ClayClay & silty clayOrganic soilClayClay & silty clayClay & silty clay
Clay & silty clay
Clay
Clay & silty clay
Clay
Clay & silty clayClay & silty clay
Clay
Clay & silty clayClayClay & silty clayClay
Sand & silty sandSilty sand & sandy silt
Clay & silty clay
ClayClay & silty clayClay
Clay
Clay & silty clayClay & silty clayClay
Very dense/stiff soilClayVery dense/stiff soilVery dense/stiff soil
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM 9
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
SBT legend
1. Sensitive fine grained
2. Organic material
3. Clay to silty clay
4. Clayey silt to silty
clay5. Silty sand to sandy silt
6. Clean sand to silty sand
7. Gravely sand to sand
8. Very stiff sand to
clayey sand9. Very stiff fine grained
This software is licensed to: CTE, Inc.CPT name: CPT-2
Norm. cone resistance
Qtn
200150100500Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. cone resistance
CP T ba s ic in t e r p r e t a t io n pl o t s ( no r ma l iz e d)
Norm. friction ratio
Fr (%)
1086420Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. friction ratio Nom. pore pressure ratio
Bq
10.80.60.40.20-0.2Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Nom. pore pressure ratio SBTn Plot
Ic (Robertson 1990)
4321Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBTn Plot Norm. Soil Behaviour Type
SBTn (Robertson 1990)
1817161514131211109876543210Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. Soil Behaviour Type
Silty sand & sandy siltVery dense/stiff soilClay & silty clay
Clay & silty clayClay & silty clay
Clay & silty clay
Silty sand & sandy siltSilty sand & sandy siltSilty sand & sandy silt
Clay
Clay & silty clay
Clay
Clay & silty clay
Clay
Clay & silty clayClay & silty clay
Clay
Clay & silty clayClay & silty clay
Clay & silty clayClay
Sand & silty sand
Silty sand & sandy silt
Clay
Clay & silty clay
Clay
Clay & silty clay
ClayClay & silty clayVery dense/stiff soilClay
Very dense/stiff soilVery dense/stiff soil
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM 10
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
SBTn legend
1. Sensitive fine grained
2. Organic material
3. Clay to silty clay
4. Clayey silt to silty
clay5. Silty sand to sandy silt
6. Clean sand to silty sand
7. Gravely sand to sand
8. Very stiff sand to
clayey sand9. Very stiff fine grained
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
This software is licensed to: CTE, Inc.CPT name: CPT-2
Total cone resistance
qt (tsf)
4003002001000Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Total cone resistance
Liq ue f a c t io n a na l y s is o v e r a ll pl o t s ( int e r me di a t e r e s ult s )
SBTn Index
Ic (Robertson 1990)
4321Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBTn Index Norm. cone resistance
Qtn
200150100500Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. cone resistance Grain char. factor
Kc
109876543210Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Grain char. factor Corrected norm. cone resistance
Qtn,cs
200150100500Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Corrected norm. cone resistance
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM 11
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
This software is licensed to: CTE, Inc.CPT name: CPT-2
CRR plot
CRR & CSR
0.60.40.20Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
CRR plot
During earthq.
Li que f a c t i o n a na ly s is o v e r a l l p lo t s
FS Plot
Factor of safety
21.510.50Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
FS Plot
During earthq.
Liquefaction potential
LPI
20151050Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Liquefaction potential Vertical settlements
Settlement (in)
2.521.510.50Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Vertical settlements Lateral displacements
Displacement (in)
403020100Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Lateral displacements
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM 12
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
F.S. color scheme LPI color schemeInput parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
Almost certain it will liquefy
Very likely to liquefy
Liquefaction and no liq. are equally likely
Unlike to liquefy
Almost certain it will not liquefy
Very high risk
High risk
Low risk
This software is licensed to: CTE, Inc.CPT name: CPT-2
Normalized friction ratio (%)
0.1 1 10Normalized CPT penetration resistance1
10
100
1,000
Li que f a c t i o n a n a ly s is s umma r y p lo t s
Qtn,cs
200180160140120100806040200Cyclic Stress Ratio* (CSR*)0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Liquefaction
No Liquefaction
Thickness of surface layer, H1 (m)
109876543210Thickness of liquefiable sand layer, H2 (m)12.0
11.0
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
CPT-2 (25.43)
Analysis PGA: 0.59
PGA 0.40g - 0.50gCLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM 13
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
This software is licensed to: CTE, Inc.CPT name: CPT-2
Norm. cone resistance
Qtn
200100Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. cone resistance
Che c k f o r s t r e n gt h lo s s plo t s ( Ro be r t s o n ( 201 0) )
Grain char. factor
Kc
109876543210Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Grain char. factor Corrected norm. cone resistance
Qtn,cs
200150100500Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Corrected norm. cone resistance SBTn Index
Ic (Robertson 1990)
4321Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBTn Index Liquefied Su/Sig'v
Su/Sig'v
0.50.40.30.20.10Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
Peak Su ratio Liq. Su ratio
Liquefied Su/Sig'v
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM 14
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
LIQUEFA CTION A NA L YS IS RE PORT
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
.
G.W.T. (in-situ):
G.W.T. (earthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Project title : CTE / Harle Residence Location : 4547 Cove Dr, Carlsbad, CA
Kehoe Testing and Engineering
714-901-7270
steve@kehoetesting.com
www.kehoetesting.com
CPT file : CPT-3
6.00 ft
2.00 ft
1
2.60
Based on SBT
Use fill:
Fill height:
Fill weight:
Trans. detect. applied:
Kσ applied:
No
N/A
N/A
Yes
No
Clay like behavior
applied:
Limit depth applied:
Limit depth:
MSF method:
All soils
No
N/A
Method based
Cone resistance
qt (tsf)
1000Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Cone resistance SBTn Plot
Ic (Robertson 1990)
4321
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBTn Plot CRR plot
CRR & CSR
0.60.40.20
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
CRR plot
During earthq.
Qtn,cs
200180160140120100806040200Cyclic Stress Ratio* (CSR*)0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Liquefaction
No Liquefaction
Normalized friction ratio (%)
0.1 1 10Normalized CPT penetration resistance1
10
100
1,000
Friction Ratio
Rf (%)
1086420
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Friction Ratio
Mw=71/2, sigma'=1 atm base curve Summary of liquefaction potential
FS Plot
Factor of safety
21.510.50
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
FS Plot
During earthq.
Zone A1: Cyclic liquefaction likely depending on size and duration of cyclic loading
Zone A2: Cyclic liquefaction and strength loss likely depending on loading and ground
geometry
Zone B: Liquefaction and post-earthquake strength loss unlikely, check cyclic softening
Zone C: Cyclic liquefaction and strength loss possible depending on soil plasticity,
brittleness/sensitivity, strain to peak undrained strength and ground geometry
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
15
This software is licensed to: CTE, Inc.CPT name: CPT-3
Cone resistance
qt (tsf)
150100500Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Cone resistance
CPT ba s ic int e r pr e t a t io n plo t s
Friction Ratio
Rf (%)
1086420Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Friction Ratio Pore pressure
u (psi)
2520151050Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Pore pressure
Insitu
SBT Plot
Ic(SBT)
4321Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBT Plot Soil Behaviour Type
SBT (Robertson et al. 1986)
1817161514131211109876543210Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Soil Behaviour Type
Clay & silty clayClay & silty clayClay
Clay
ClayClay & silty claySand & silty sandSand & silty sand
Clay
Clay & silty clay
Clay
Clay & silty claySilty sand & sandy siltClay & silty clayClay & silty clayClay
Clay & silty clayClay
Clay
Clay & silty clay
Clay
Clay & silty clayClay & silty clayClayVery dense/stiff soil
Clay
Very dense/stiff soil
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM 16
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
SBT legend
1. Sensitive fine grained
2. Organic material
3. Clay to silty clay
4. Clayey silt to silty
clay5. Silty sand to sandy silt
6. Clean sand to silty sand
7. Gravely sand to sand
8. Very stiff sand to
clayey sand9. Very stiff fine grained
This software is licensed to: CTE, Inc.CPT name: CPT-3
Norm. cone resistance
Qtn
200150100500Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. cone resistance
CP T ba s ic in t e r p r e t a t io n pl o t s ( no r ma l iz e d)
Norm. friction ratio
Fr (%)
1086420Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. friction ratio Nom. pore pressure ratio
Bq
10.80.60.40.20-0.2Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Nom. pore pressure ratio SBTn Plot
Ic (Robertson 1990)
4321Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBTn Plot Norm. Soil Behaviour Type
SBTn (Robertson 1990)
1817161514131211109876543210Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. Soil Behaviour Type
Silty sand & sandy silt
Clay & silty clayClay
ClayClay & silty clay
Clay & silty clay
Silty sand & sandy siltSilty sand & sandy silt
Clay
Clay & silty clay
Clay
Clay & silty clay
Clay
Clay & silty clay
Silty sand & sandy siltClay & silty clayClay & silty clayClayClay
Clay & silty clayClay & silty clay
Clay
Clay & silty clay
Clay
Clay & silty clay
Clay & silty clay
Clay
Very dense/stiff soil
Clay
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM 17
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
SBTn legend
1. Sensitive fine grained
2. Organic material
3. Clay to silty clay
4. Clayey silt to silty
clay5. Silty sand to sandy silt
6. Clean sand to silty sand
7. Gravely sand to sand
8. Very stiff sand to
clayey sand9. Very stiff fine grained
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
This software is licensed to: CTE, Inc.CPT name: CPT-3
Total cone resistance
qt (tsf)
15010050Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Total cone resistance
Liq ue f a c t io n a na l y s is o v e r a ll pl o t s ( int e r me di a t e r e s ult s )
SBTn Index
Ic (Robertson 1990)
4321Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBTn Index Norm. cone resistance
Qtn
200150100500Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. cone resistance Grain char. factor
Kc
109876543210Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Grain char. factor Corrected norm. cone resistance
Qtn,cs
200150100500Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Corrected norm. cone resistance
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM 18
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
This software is licensed to: CTE, Inc.CPT name: CPT-3
CRR plot
CRR & CSR
0.60.40.20Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
CRR plot
During earthq.
Li que f a c t i o n a na ly s is o v e r a l l p lo t s
FS Plot
Factor of safety
21.510.50Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
FS Plot
During earthq.
Liquefaction potential
LPI
20151050Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Liquefaction potential Vertical settlements
Settlement (in)
2.521.510.50Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Vertical settlements Lateral displacements
Displacement (in)
403020100Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Lateral displacements
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM 19
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
F.S. color scheme LPI color schemeInput parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
Almost certain it will liquefy
Very likely to liquefy
Liquefaction and no liq. are equally likely
Unlike to liquefy
Almost certain it will not liquefy
Very high risk
High risk
Low risk
This software is licensed to: CTE, Inc.CPT name: CPT-3
Normalized friction ratio (%)
0.1 1 10Normalized CPT penetration resistance1
10
100
1,000
Li que f a c t i o n a n a ly s is s umma r y p lo t s
Qtn,cs
200180160140120100806040200Cyclic Stress Ratio* (CSR*)0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Liquefaction
No Liquefaction
Thickness of surface layer, H1 (m)
109876543210Thickness of liquefiable sand layer, H2 (m)12.0
11.0
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
CPT-3 (26.13)
Analysis PGA: 0.59
PGA 0.40g - 0.50gCLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM 20
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
This software is licensed to: CTE, Inc.CPT name: CPT-3
Norm. cone resistance
Qtn
15010050Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Norm. cone resistance
Che c k f o r s t r e n gt h lo s s plo t s ( Ro be r t s o n ( 201 0) )
Grain char. factor
Kc
109876543210Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Grain char. factor Corrected norm. cone resistance
Qtn,cs
200150100500Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Corrected norm. cone resistance SBTn Index
Ic (Robertson 1990)
4321Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
SBTn Index Liquefied Su/Sig'v
Su/Sig'v
0.50.40.30.20.10Depth (ft)60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
Peak Su ratio Liq. Su ratio
Liquefied Su/Sig'v
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:34:42 PM 21
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
Input parameters and analysis data
Analysis method:
Fines correction method:
Points to test:
Earthquake magnitude Mw:
Peak ground acceleration:
Depth to water table (insitu):
Robertson (2009)
Robertson (2009)
Based on Ic value
6.90
0.59
6.00 ft
Depth to water table (erthq.):
Average results interval:
Ic cut-off value:
Unit weight calculation:
Use fill:
Fill height:
2.00 ft
1
2.60
Based on SBT
No
N/A
Fill weight:
Transition detect. applied:
Kσ applied:
Clay like behavior applied:
Limit depth applied:
Limit depth:
N/A
Yes
No
All soils
No
N/A
Kehoe Testing and Engineering
714-901-7270
steve@kehoetesting.com
www.kehoetesting.com
Overall vertical settlements report
Project title : CTE / Harle Residence
Location : 4547 Cove Dr, Carlsbad, CA
CPTu NameCPT-1CPT-2CPT-3Vertical settlement (in)6.50
6.00
5.50
5.00
4.50
4.00
3.50
3.00
2.50
2.00
1.50
1.00
0.50
0.00
6.343
2.84 2.696
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software 1
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
Kehoe Testing and Engineering
714-901-7270
steve@kehoetesting.com
www.kehoetesting.com
Overall Parametric Assessment Method
Analysis
Settlements vs PGA
CPTu Name
CPT-1 CPT-2 CPT-3Settlements (in)8
7.5
7
6.5
6
5.5
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
Robertson (NCEER 2001)
Robertson (2009)
Idriss & Boulanger (2008)
Moss et al. (2006)
Boulanger & Idriss (2014)
:: CPT main liquefaction parameters details ::
GWT in situ
(ft)
CPT Name Earthquake
Mag.
Earthquake
Accel.
GWT earthq.
(ft)
CPT-1 6.90 0.59 6.00 2.00
CPT-2 6.90 0.59 6.00 2.00
CPT-3 6.90 0.59 6.00 2.00
CLiq v.3.0.3.4 - CPT Liquefaction Assessment Software - Report created on: 2/25/2021, 3:36:09 PM
Project file: C:\Users\rodney\Desktop\ASCE 7-16 CPTs.clq
1
APPENDIX F
I-8 INFILTRATION FEASIBILITY
I-8
I-8
X
The NRCS soils across the site are all Type D soils with very high surface runoff. Three soil types
were present in the area of the proposed development, Quaternary Previously Placed Fill, Young
Alluvial Flood Plain Deposits, and Tertiary Santiago Formation.
Percolation testing was not performed due to shallow groundwater (six feet bgs).
X
Shallow groundwater was encountered at the site and the site is located adjacent to Agua Hedionda
Lagoon, therefore groundwater mounding potential exists at the site.
I-8
I-8 X
Due to shallow groundwater at the site, infiltrating stormwater could potentially impact
groundwater.
X
The site is located adjacent to Agua Hedionda Lagoon, therefore infiltrating water could
potentially impact the lagoon.
No Full
I-8
X
The site is not suitable for infiltration due to shallow groundwater and proximity to Agua
Hedionda Lagoon.
X
Shallow groundwater was encountered at the site and the site is located adjacent to Agua
Hedionda Lagoon, therefore groundwater mounding potential exists at the site.
I-8
X
Due to shallow groundwater at the site, infiltrating stormwater could potentially impact
groundwater.
X
The site is located adjacent to Agua Hedionda Lagoon, therefore infiltrating water could
potentially impact the lagoon.
No Inf.
May 19, 2021 CTE Project No. 10-15981G
KWD Holdings, LLC
Attention: Mr. John Darlington
265 Via Del Monte
Oceanside, California 92058522 G Avenue
Telephone: (619) 733-8379 Email: darlingtonconsulting@yahoo.com
Subject: Response to Third-Party Geotechnical Review (Second)
Serving as Addendum 01 to the Geotechnical Report (CTE 2/2021)
Proposed Residential Duplex
4547 Cove Drive, Carlsbad, California
References: Appendix A
Mr. Darlington:
As requested, Construction Testing & Engineering Inc., (CTE) has completed our responses to
the referenced and attached City of Carlsbad’s Third-Party Geotechnical Review (second)
performed by Hetherington Engineer, Inc. for the proposed residential improvements, located at
4547 Cove Drive in Carlsbad, California. The numbers for the responses below correspond to
the comments in the attached Review letter, dated April 22, 2021. The Comments are numbered
1 through 10. Additionally, comment responses are provided for geotechnical related City of
Carlsbad redline comments from Plan check 2, LDE by EME dated 4-8-2021
Comment Issue No.1: The Consultant should identify which of the various remedial
grading/foundation recommendations will be used in the construction of the project. (Second
Request)
Response: As CTE understands, structural improvements will be supported by an Auger Cast in
Place Pile/ grade beam foundations system. Lightly loaded and structurally separated exterior
improvements such as pavements, basins, and retaining walls will be supported by isolated
shallow foundations on properly prepared subgrade as recommend in the referenced geotechnical
recommendation report.
Comment Issue No. 2: The Consultant should provide and updated geotechnical map/plot plan
utilizing the latest grading plan for the project to clearly show (at a minimum), a) existing site
topography, b) proposed structures/improvements, c) proposed finished grades, d) locations of
Response to Third-Party Geotechnical Review (Second) Page 2
Serving as Addendum 01 to the Geo Report (CTE 2/2021)
Proposed Residential Duplex, 4547 Cove Drive, Carlsbad, California
May 19, 2021 CTE Job No. 10-15981G
\\file01\CTE Share\Projects\10-15000 to 10-15999 Projects\10-15981G\Comments and Responses\Ltr_Resp to Comments.doc
the subsurface exploration, e) geologic contacts, f) remedial grading limits, g) locations of
shoring, etc. (Second Request).
Response: A full version of the latest civil plans will be submitted along side this letter showing
remedial grading limited. Attached is Figure 2 showing a plan view of the proposed grading
along with geologic contacts, subsurface boring locations overlaid by CTE.
Comment Issue No. 3: The Consultant should provide geologic cross-sections utilizing the
current grading plan to clearly show (at a minimum), a) existing site topography, b) proposed
structures/improvements, c) proposed finished grades, d) geologic contacts, e) geologic structure,
f) locations of the subsurface exploration, g) temporary construction slopes, shoring, and h)
remedial grading, etc. (Second Request).
Response: The requested geologic cross-sections utilizing the current grading plans is attached
as Figure 2A.
Comment Issue No. 4: The Consultant should review the project grading, shoring, dewatering,
and foundation plans, provide any additional geotechnical recommendations considered
necessary, and confirm that the plans have been prepared in accordance with the geotechnical
recommendations provided in the referenced reports (Second Request).
Response: This comment response letter serves as a foundation and grading plan review letter.
Grading and foundation plans have been reviewed and are in substantial conformance with the
recommendation presented in the reference geotechnical documents. As such, no shoring or
dewatering is proposed based on the foundation type and installation methods. Basin
excavations are discussed in Issues No. 6 response.
Comment Issue No.5: The Consultant should provide a detailed description of proposed site
grading, structures/improvements, foundation type, etc.
Response: To be completed by the DOR. As CTE understands, site grading will consist of an
18-inch overexcavation in building pad and exterior improvement areas. Auger Cast in Place
piles will be drilled followed by the construction of grade tie-beams within the building
footprint.
Comment Issue No.6: The Consultant should provide shoring recommendations, as necessary.
Response: Due to the cohesive nature and anticipated unconfined compressive strength of the of
the near surface site soils, shoring is not anticipated to be necessary for the proposed relatively
shallow site excavations (less than four [4] feet). Additionally, in accordance with OSHA
trenching and excavation safety bulletin, the basin excavations will be classified as a trench
excavation based on dimensions/ depth. Trenches less than five [5] feet deep, as approved by a
competent person, do not require a protective system (shoring). In order to reduce the potential
Response to Third-Party Geotechnical Review (Second) Page 3
Serving as Addendum 01 to the Geo Report (CTE 2/2021)
Proposed Residential Duplex, 4547 Cove Drive, Carlsbad, California
May 19, 2021 CTE Job No. 10-15981G
\\file01\CTE Share\Projects\10-15000 to 10-15999 Projects\10-15981G\Comments and Responses\Ltr_Resp to Comments.doc
for minor surgical sloughing, the temporary excavation can be cut vertical for the lower three [3]
feet and laid back at a 1.5:1 (horizontal: vertical) for the upper one [1] foot of excavation
(assuming a 4 foot excavation).
Comment Issue No.7: The Consultant should address the downdrag and lateral spread forces on
the proposed drilled piles.
Response: Pile design and liquefaction analysis presented in the refenced geotechnical
recommendation report addressed both vertical capacity and lateral spreading potential.
Potential downdrag due to liquefiable soils was also addressed in the capacity calculations for the
proposed supporting piles. Should calculations need to be reiterated, CTE can provide upon
request.
Comment Issue No.8: The Consultant should provide the Risk Category and Seismic Design
Category.
Response: Risk Category II and Seismic Design Category of D have been designated for the
proposed improvements
Comment Issue No.9: The Consultant should provide a statement regarding the impact to
adjacent properties and improvements.
Response: Based on the proposed construction, there is anticipated to be no impact on adjacent
properties or their existing improvements. Construction activities related to the grading and
geotechnical aspects of the project should be reviewed and observed by a CTE representative.
Should unforeseen conditions requiring modified recommendations arise, city will be notified.
Comment Issue No.10: The Consultant should provide a list of recommended observation and
testing during site grading and construction.
Response: All foundation excavations, including, but not limited to, Auger Cast in place pile
installation, basin and retaining wall excavations, overexcavations, all backfill placement and
compaction should be observed and tested, as necessary.
REDLINE COMMENTS FROM PLAN CHECK
Redline Issue Sheet 2 of 6: Regarding How will thie S.D. installation be handled since the
armored slope is not to be altered or disturbed.
Response: CTE recommends carful removal, construction of storm drain, replace-as-removed
under the supervision of CTE representative to ensure the armored slope erosion control system
is not compromised and reconstructed as-removed or superior. Installation of storm drain
Response to Third-Party Geotechnical Review (Second) Page 4
Serving as Addendum 01 to the Geo Report (CTE 2/2021)
Proposed Residential Duplex, 4547 Cove Drive, Carlsbad, California
May 19, 2021 CTE Job No. 10-15981G
\\file01\CTE Share\Projects\10-15000 to 10-15999 Projects\10-15981G\Comments and Responses\Ltr_Resp to Comments.doc
without temporarily disturbing armored slope does not appear feasible based on existing and
proposed conditions.
Redline Issue Sheet 2 of 6: Specify mat foundation or piers.
Response: As CTE understands, the structure is to be supported by pile/pier foundations as
recommended in the referenced geotechnical investigation (CTE 2021). Additionally, the 18”
slab comment is no longer relevant since the structure is to be pile supported.
Redline Issue Sheet 2 of 6: Show cutline and provide per soils engineer. [regarding basin
shoring/temp slope]
Response: This was addressed in the aforementioned Comment Issue No. 6 response.
Redline Issue Sheet 3 of 6: Show geotextile/ ground stabilization layer as recommended by
soils report.
Response: High strength geosynthetic fabric was only recommended for the deep
overexcavation and recompaction recommendation (floating mat), and it not necessary for a
pile/pier supported structure.
Redline Issue Sheet 3 of 6: Min 2’ per page 14 soils report. (with regards to the minimum
overexcavation required throughout the site)
Response: Overexcavation of site improvements/building pad area may be reduced to 18 inches
below existing, proposed subgrade or the depth of competent materials (as determined by CTE)
whichever. Overexcavation should be followed by a six to eight inch scarification prior to fill
placement and compaction. Fill should be placed and compacted as recommended in the
referenced geotechnical report (CTE 2021). Additionally, CTE should observe and approve the
bottom of all overexcavations prior to scarification, fill placement, and compaction.
Redline Issue Sheet 3 of 6: Show Cutback at 1.5:1 / remove overex line from adjacent
properties.
Response: This item will be addressed by Comment Issue No. 6 response.
Redline Issue Sheet 3 of 6: Provide soils engineer recommendation (subdrain?, impermeable
liner?, Structural Section; etc.) [with regards to the paver section detail]
Response: Permeable pavers should be installed over properly compacted aggregate base.
Subgrade prepared in accordance with the geotechnic report (CTE 2021) and modification in this
letter should be sloped at a gradient to promote drainage toward a filter fabric wrapped
perforated pipe that discharges in an appropriate location. If desired for the longevitiy of the
Response to Third-Party Geotechnical Review (Second) Page 5
Serving as Addendum 01 to the Geo Report (CTE 2/2021)
Proposed Residential Duplex, 4547 Cove Drive, Carlsbad, California
May 19, 2021 CTE Job No. 10-15981G
\\file01\CTE Share\Projects\10-15000 to 10-15999 Projects\10-15981G\Comments and Responses\Ltr_Resp to Comments.doc
paver surfaces, a impermeable liner may be placed between the subgrade and aggregate base
layer. A separation layer/leveling course [pea gravel or similar] may be used if desired.
Recommended structural sections presented below.
TABLE
PERMEABLE PAVER SECTION THICKNESS
Traffic Area Assumed
Traffic Index
Preliminary
R-Value
Asphalt Pavements
Permeable Paver
Approximate
Thickness
(inches)
Class II
Aggregate
Base
Thickness
(inches)*
Drive Areas 5.5 5+ 3 12
Auto Parking
Areas/Walkways 4.5 5+ 3 9
*Class II permeable base may be used in lieu of Class II base to promote drainage.
This document is subject to the same limitations as our previous geotechnical documents.
The opportunity to be of service is appreciated. If you have any questions, please do not hesitate
to contact this office.
Respectfully submitted,
CONSTRUCTION TESTING & ENGINEERING, INC.
Dan T. Math, GE #2665 Rodney J. Jones, RCE #84232
Principal Engineer Senior Engineer
RJJ/DTM:ach
Appendix A—Reference
Appendix B—City Comments
Attachments—Figure 2 (rev) - Geotechnical Map/Plot
Figure 2A - Geologic Cross Section
AA'TD=79.5'TD=60.2'TD=60.4'TD=56.5'0-10-20-30-40-50-60-70CPT-3CPT-2CPT-1HA-1HA-2*B-1*B-2TD=10'TD=16.5'TD=10'EXPLANATIONCPT-3APPROXIMATE CPT LOCATIONHA-2APPROXIMATE HAND AUGER LOCATION*B-1APPROXIMATE BORING LOCATION (VINJE & MIDDLETON ENG, INC. REPORT 2004)QppfQUATERNARY PREVIOUSLY PLACED FILLQaALLUVIAL FLOOD PLAIN DEPOSITSTsaTERTIARY SANTIAGO FORMATIONAPPROXIMATE GEOLOGIC CONTACTQppfQppfQppfQaQaQaQaQaTsaTsaTsaTsaQa
APPENDIX A
REFERENCES
REFERENCES
1. Third-Party Geotechnical Review (Second), Proposed Residential Duplex, 4745 Cove
Drive, Carlsbad, California, SD Project ID: PD 2020-0047, Hetherington Engineering,
Inc. Project No. 9268.1 dated April 22, 2021
2. Geotechnical Investigation, Proposed Harle Residence, 4547 Cove Drive, Carlsbad,
California, Construction Testing and Engineering, Inc., Project No. 10-15981G, Dated
February 26, 2021
3. Grading Plans For: Harle Residence, 4547 Cove Drive, Carlsbad, CA, Prepared by Civil
Landworks, Project No. PC202-0047, Dated October 8, 2020
4. Geotechnical Update Report, Proposed Residential Duplex Development, Existing Pad
(Lot 31) 4547 Cove Drive, Carlsbad, California, Prepared By SMS Geotechnical
Solutions, Project No. GI-16-06-128, Dated July 25, 2016
APPENDIX B
CITY OF CARLSBAD REVIEW COMMENTS
June 28, 2021 CTE Project No. 10-15981G
KWD Holdings, LLC
Attention: Mr. John Darlington
265 Via Del Monte
Oceanside, California 92058
Telephone: (619) 733-8379 Email: darlingtonconsulting@yahoo.com
Subject: Gravity Wall Drainage Recommendations
Proposed Harle Residence
4547 Cove Drive
Carlsbad, California
References: Appendix A
Mr. Darlington:
As requested, Construction Testing & Engineering Inc., (CTE) has reviewed the proposed
gravity retaining wall and provides the following conceptual recommendations for wall drainage.
Retaining walls should have either a 6-inch gravel drainage section (separated by filter fabric)
OR appropriate drainage board that feeds water from behind the wall to a gravel and filter fabric
wrapped perforated pipe (“burrito drain”) at the heel of the wall. Gravel drainage
section/drainage board can be terminated 6 to 12 inches below the top of wall elevation.
A CTE representative should verify construction/installation of site retaining walls and
associated drainage systems. This document is subject to the same limitations as our previous
geotechnical documents.
The opportunity to be of service is appreciated. If you have any questions, please do not hesitate
to contact this office.
Respectfully submitted,
CONSTRUCTION TESTING & ENGINEERING, INC.
Dan T. Math, GE #2665 Rodney J. Jones, RCE #84232
Principal Engineer Senior Engineer
RJJ/DTM:ach
Attachments: Appendix A—Reference
APPENDIX A
REFERENCES
REFERENCES
1. Geotechnical Investigation, Proposed Harle Residence, 4547 Cove Drive, Carlsbad,
California, Construction Testing and Engineering, Inc., Project No. 10-15981G, Dated
February 26, 2021
2. Grading Plans For: Harle Residence, 4547 Cove Drive, Carlsbad, CA, Prepared by Civil
Landworks, Project No. PC202-0047, GR2020-0033
3. Geotechnical Update Report, Proposed Residential Duplex Development, Existing Pad
(Lot 31) 4547 Cove Drive, Carlsbad, California, Prepared By SMS Geotechnical
Solutions, Project No. GI-16-06-128, Dated July 25, 2016