HomeMy WebLinkAboutCT 2022-0003; CARLSBAD BY THE SEA SUMMERHOUSE; GEOTECHNICAL INVESTIGATION; 2022-02-25
GEOTECHNICAL INVESTIGATION
Proposed Memory Care and Independent Living Facility
Ocean Street, APNs 203-144-0400, 0500, 0600, 0700, and 0800
Carlsbad, California
prepared for:
Mr. Joseph Butler
Front Porch Communities and Services
800 N. Brand Boulevard
Glendale, CA 91203
by:
TerraPacific Consultants, Inc.
4010 Morena Boulevard, Suite 108
San Diego, CA 92117
February 25, 2022
File No. 22-041
a
4010 Morena Boulevard, Suite 108 • San Diego, CA 92117 • (858) 521-1190 • (858) 521-1199 fax • terrapac.net
Mr. Joseph Butler February 25, 2022
Front Porch Communities and Services File No. 22-041
800 N. Brand Boulevard
Glendale, CA 91203
Subject: Geotechnical Investigation
Proposed Memory Care and Independent Living Facility
Ocean Street, APNs 203-144-0400, 0500, 0600, 0700 and 0800
Carlsbad, California
Dear Mr. Butler:
In accordance with our proposal dated February 18, 2022, TerraPacific Consultants, Inc.
(TCI) has prepared the following report presenting our findings and recommendations
from a geotechnical investigation at the subject property. The purpose of the
investigation was to evaluate the subsurface conditions at the site and provide
recommendations and geotechnical design parameters for the proposed construction.
The following report contains a summary of our findings and recommendations.
We greatly appreciate the opportunity to be of service. If you should have any questions
or comments regarding this report or our findings, please contact our office.
Sincerely,
TerraPacific Consultants, Inc.
Cristopher C. O’Hern, CEG 2397 Octavio Brambila, PE 70633
Senior Engineering Geologist Project Engineer
CCO/OB:gg
Digitally signed by
Cristopher O'Hern
Date: 2022.02.25
11:15:32 -08'00'
Digitally signed by
Octavio Brambila
Date: 2022.02.25
11:16:04 -08'00'
TABLE OF CONTENTS
1.0 INTRODUCTION ............................................................................................................. 1
1.1 General ................................................................................................................1
1.2 Scope of Services ...............................................................................................1
2.0 PROJECT BACKGROUND .............................................................................................. 2
2.1 Site Description and Development History .......................................................2
2.2 Proposed Development ......................................................................................2
3.0 SITE INVESTIGATION .................................................................................................... 2
3.1 Site Reconnaissance ...........................................................................................2
3.2 Subsurface Exploration ......................................................................................3
3.3 Laboratory Testing .............................................................................................3
4.0 SITE GEOLOGY .............................................................................................................. 3
4.1 Geologic Setting .................................................................................................3
4.2 Site Stratigraphy .................................................................................................4
4.3 Groundwater .......................................................................................................4
5.0 SEISMICITY .................................................................................................................... 5
5.1 Regional Seismicity ............................................................................................5
5.2 Probabilistic Ground Acceleration .....................................................................5
5.3 Hazard Assessment ............................................................................................6
6.0 CONCLUSIONS .............................................................................................................. 7
7.0 RECOMMENDATIONS ................................................................................................... 7
7.1 Site Preparation and Grading ............................................................................8
7.2 Temporary Excavations ......................................................................................8
7.3 Foundation Recommendations ..........................................................................9
7.4 Soil Design Criteria .............................................................................................9
7.5 Retaining Walls .................................................................................................10
7.6 Earthquake Design Parameters ........................................................................11
7.7 Foundation and Retaining Wall Design Guidelines ........................................11
7.8 Trench Backfill...................................................................................................13
7.9 Pavement ..........................................................................................................13
7.10 Site Drainage ....................................................................................................14
7.11 Plan Review and Geotechnical Observation ...................................................15
8.0 CLOSURE...................................................................................................................... 15
8.1 Limits of Investigation ......................................................................................15
APPENDICES
Appendix A: Figures
Appendix B: References
Appendix C: Subsurface Excavation Logs
Appendix D: Laboratory Test Results
Appendix E: Summary of Active Faults
Appendix F: Standard Grading Guidelines
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1.0 INTRODUCTION
1.1 General
The following report presents the findings of a geotechnical investigation performed at
the property with APNs 203-144-0400, 0500, 0600, 0700, and 0800 in Carlsbad, California.
The property's location is presented on the Site Location Plan, Figure 1 in Appendix A.
The purpose of the investigation was to evaluate the subsurface conditions at the site to
provide recommendations and soil design parameters for the proposed construction.
1.2 Scope of Services
The scope of the investigation consisted of field reconnaissance, subsurface exploration,
laboratory testing, and engineering and geologic analysis of the obtained data. The
following tasks were performed during the investigation and production of this report:
Site reconnaissance and review of published geologic, seismologic, and
geotechnical reports and maps pertinent to the project. A list of references is
provided in Appendix B.
Logging/sampling of six small-diameter borings at the subject property. The
Geotechnical Plan, Figure 1 in Appendix A, presents the approximate subsurface
exploration locations. The excavation logs are presented in Appendix C.
Collection, testing, and analysis of representative soil samples from selected
depths within the excavations.
Laboratory testing of samples collected from the test excavations. The testing
included in-situ moisture and density, hydro-collapse, grain size analysis, direct
shear, maximum density/optimum moisture, and sulfate and chloride levels. The
laboratory data is presented in Appendix D.
Engineering and geologic analysis of data acquired from the investigation, which
provided the basis for our conclusions and recommendations.
Preparation of this report presenting our findings and recommendations.
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2.0 PROJECT BACKGROUND
2.1 Site Description and Development History
The subject property is located on the northern side of Ocean Street in Carlsbad,
California. The legal description of the property is APNs 203-144-0400, 0500, 0600, 0700,
and 0800, Lots 1 through 4, Ocean Street, Submap No. 015639, and Lot 5, Garfield Street,
Submap No. 015639, Carlsbad, California. The combined five lots are rectangular in shape
and are bordered by Beech Street to the north, Garfield Street to the east, a paved parking
lot to the south, and Ocean Street to the west.
Topography descends gently in a western direction from Garfield Street towards Ocean
Street. Lot elevations range from approximately 51 feet to 41 feet above mean sea level
(MSL). The lot is currently undeveloped and covered with vegetation consisting of
seasonal grass and small plants.
2.2 Proposed Development
Based on our review of the current conceptual plans, it is our understanding that a new
memory care and independent living facility, consisting of 3 stories of habitable living space
over a subterranean parking lot, along with associated appurtenances, is planned. Due to
the proposed subterranean construction and proximity to the property lines it is anticipated
that temporary shoring walls will be utilized for the construction.
3.0 SITE INVESTIGATION
The site investigation was conducted on February 17, 2022, and consisted of visual
reconnaissance and subsurface exploration. The purpose of the investigation was to gain
an understanding of the site configuration and subsurface conditions in the vicinity of the
proposed construction.
3.1 Site Reconnaissance
Our site reconnaissance consisted of walking the site to determine if any adverse
geologic conditions were present. No outward signs of distress indicating adverse
geologic conditions were noted.
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3.2 Subsurface Exploration
The subsurface exploration consisted of six small-diameter borings excavated with a
truck-mounted drill rig. The borings, B-1 through B-6, were excavated in the approximate
areas of planned improvements extended to depths ranging from 9.0 to 36.5 feet below
ground surface (bgs). The approximate excavation locations are presented in the
Geotechnical Plan, figure 2 in Appendix A. The borings were logged and sampled by a
licensed professional from our office.
In general, the subsurface exploration revealed that the site is mantled by shallow fill,
underlain by native old paralic deposits. Descriptions of each material are detailed in
Section 4.2 Site Stratigraphy, and the subsurface excavation logs are provided in
Appendix C.
3.3 Laboratory Testing
Soil samples collected during the field exploration were tested to characterize the soil
types and evaluate the engineering properties of the soil. The laboratory testing included
in-situ moisture and density, grain size analysis, hydro-collapse, direct shear, sulfate and
chloride levels, and maximum density/optimum moisture. Each laboratory test was
performed per ASTM specifications or other accepted testing procedures. The results of
the laboratory tests are presented in Appendix D.
4.0 SITE GEOLOGY
4.1 Geologic Setting
The site is located within the coastal portion of California's Peninsular Ranges
Geomorphic Province. This province, which extends 900 miles from Southern California
to the southern tip of Baja California, is characterized by northwest-trending structural
blocks. The coastal portion of the province in San Diego County is typically comprised of
upper Cretaceous-aged to Tertiary-aged (1.8 million to 65 million years) marine and non-
marine sedimentary bedrock units deposited within a northwest-trending basin known as
the San Diego Embayment (Norris & Webb, 1976). Recent geologic uplift along the San
Diego coastal margin, combined with sea-level changes, has created marine terraces and
associated deposits of near-shore marine, beach estuarine, and lagoonal facies. These
deposits range from early to mid-Quaternary-aged (45,000 to 1.5 million years) and are
designated in geologic literature as paralic deposits.
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According to the geologic literature, the site is underlain by Quaternary-aged surficial
deposits designated as Old Paralic Deposits, Unit 6-7. Geologic literature describes the
paralic deposits as “poorly sorted, moderately permeable, reddish-brown, interfingered
strandline, beach, estuarine and colluvial deposits composed of siltstone, sandstone, and
conglomerate” (Kennedy and Tan, 2008). The site is located on the Geologic Map, Figure 3
in Appendix A.
4.2 Site Stratigraphy
The following subsurface descriptions are interpreted from the conditions exposed during
the field investigation and/or inferred from local geologic literature. In addition, detailed
exploration logs are presented in Appendix C.
Fill Soil - Fill soil is earth material that has been placed using mechanical means such as
dozers or other large earthmovers. Typically, the fill soil has been removed from
topographically high locations and placed in low-lying areas to create level building pads.
When properly compacted, fill soil can be used to support structures. However, it is
typically more compressible than natural formational soils.
Shallow fill soils were encountered in each excavation within the approximate upper 2 to
4 feet of borings. The fill soils were relatively consistent and were generally described as
a light orange-brown to red-brown silty sand that moist to slightly moist and loose in
consistency.
Native Surficial Deposits - Old Paralic Deposits, Unit 6-7 (Qop6-7) - Terrace deposits
designated Quaternary-aged Old Paralic Deposits, Unit 6-7 were encountered in each of
the borings underlying the fill material. The paralic deposits are associated with the
Nestor marine terrace and are approximately 120,000 years old. The material encountered
during our exploration was generally described as a medium orange-brown to red-brown
silty sandstone that was moist to very moist and medium dense to dense in consistency.
4.3 Groundwater
Static groundwater was encountered within Boring B-6 at a depth of 32 feet (bgs). It
should be mentioned that transient perched groundwater conditions can develop at
different levels within the soil profile due to future irrigation patterns, periods of
prolonged rainfall, and/or other conditions related to off-site development. Zones of
seepage or perched groundwater may be encountered during construction excavations
and dewatering systems may be required.
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5.0 SEISMICITY
5.1 Regional Seismicity
Generally, the seismicity within California can be attributed to the regional tectonic
movement taking place along the San Andreas Fault Zone, which includes the San
Andreas Fault and most parallel and sub-parallel faulting within the state. A majority of
Southern California, including the subject site, is considered seismically active. Seismic
hazards can be attributed to potential ground shaking from earthquakes along nearby
faults or more distant faulting.
According to regional geologic literature, the closest known active faults are located
within the Rose Canyon Fault Zone. The Rose Canyon Fault Zone consists of a complex
zone of several en echelon strike-slip, oblique, reverse, and normal faults, extending
onshore in San Diego from San Diego Bay north to La Jolla Bay, and off-shore along
North County San Diego. Several other potentially active and pre-Quaternary faults also
occur within the regional vicinity. Currently, the geologic literature presents varying
opinions regarding the seismicity of these faults; as such, the following seismic analysis
only considers the effects of nearby faults currently considered active.
5.2 Probabilistic Ground Acceleration
A deterministic seismic hazard analysis was performed for the site using the computer
program EQFault (Blake, 2000). The analysis considers the maximum movement
magnitude earthquake for active faults within the specified search radius to provide a
maximum expected earthquake event for the known tectonic structure. For this site, we
specified a search radius of 62.4 miles (100 km) and the conservative attenuation equation
of Campbell & Bozorgnia (1997 Rev.) for alluvium. The analysis results for the faults most
likely to affect the site are presented in Appendix E, Summary of Active Faults.
A simplified probabilistic seismic hazard analysis was also performed for the site. The
California Geological Survey has a webpage that allows a user to calculate the ground
motion at a site with both a 2 percent and 10 percent probability of exceedance in 50
years. The output results indicated the site had respectively calculated peak ground
accelerations of 0.56g and 0.30g.
The values provided above compare the potential for seismic shaking due to fault activity
most likely to affect the site. Other factors should be considered when completing the
seismic design, such as duration of shaking, the period of the structure, design category,
etc. The design and/or structural engineer should consider the information provided
herein and evaluate the structure(s) per the 2019 California Building Code (CBC) and
guidelines of the City of San Diego. The earthquake design parameters based on the 2019
CBC applicable to the site are provided in Section 7.6.
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5.3 Hazard Assessment
Faulting/Fault Rupture Hazard - An “active” fault defined by the Alquist-Priolo Earthquake
Fault Zoning Act is a fault that has had surface rupture within Holocene time (the past
11,000 years). A “potentially active” fault is defined as any fault that showed evidence of
surface displacement during Quaternary time (last approximately 1.6 million years), but
not since Holocene time.
According to the City of San Diego Seismic Safety Study 2008 and the Quaternary Fault
Map from the USGS Earthquake Hazards Program, the subject parcel is located
approximately 4 miles southeast of an “active” off-shore portion of the Rose Canyon
Fault Zone (Oceanside Section) and 2 miles east of a “potentially active” off-shore portion
of the Rose Canyon Fault Zone (Oceanside Section). According to geologic literature, the
site is not located within an Alquist-Priolo Fault Zone and is not intersected by any faults.
Seismically Induced Settlement - The soils encountered within the depths of our
exploration consisted of predominately medium-grained, medium dense to dense native
soils. Based on the anticipated earthquake effect and the site's stratigraphy, seismically
induced settlement is expected to be minor and within tolerable limits. Structures
designed and constructed according to applicable building codes are expected to perform
well with respect to settlement associated with predictable seismic events.
Liquefaction - Liquefaction involves the substantial loss of shear strength in saturated
soil, usually taking place within a saturated medium exhibiting a uniform fine-grained
characteristic, loose consistency, and low confining pressure when subjected to impact
by seismic or dynamic loading. Based on the relatively dense nature of the underlying
native paralic deposits, the site is considered to have a negligible risk for liquefaction.
Lurching and Shallow Ground Rupture - Rupturing of the ground is not likely due to the
absence of known active fault traces within the project limits. Due to the generally active
seismicity of Southern California; however, the possibility for ground lurching or rupture
cannot be completely ruled out. In this light, a “flexible” design for on-site utility lines
and connections should be considered.
Landsliding - Given the shallow topographic relief of the site and surrounding area, the
possibility for landsliding is believed to be remote. Furthermore, geologic literature does
not depict any known landslides in the vicinity of the site.
Seiches and Flooding - At the time of our investigation, there were no nearby contained
bodies of water that could produce seiches (“tidal” waves in confined bodies of water)
that may affect the site. No seiche or flooding potential was identified.
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Tsunamis - Tsunamis are great sea waves produced by seismic events. Given the site
elevation (41 feet MSL), it is not likely that a tsunami could impact the site. Historically,
the magnitudes of tsunamis to impact the San Diego coastline have been fairly small,
typically less than 1 meter in height. Recent studies into the possibility of offshore seismic
events triggering tsunamis via fault movement or undersea landslides have experts of the
opinion that Southern California is not free from tsunami risks (Krier, 2005). However,
predicting the level of risk is difficult due to the lack of knowledge about the offshore fault
system. In our opinion, there is no practical approach for mitigating the potential impact
to the site from a tsunami, and it is inherent for those living within the beach area. The
homeowner(s) should have an evacuation plan in place for a strong seismic event (i.e.,
typically 20 seconds or more of sturdy ground shaking) or when an official tsunami
warning is issued.
6.0 CONCLUSIONS
Based on the results of our investigation, it is our opinion that the proposed development
is feasible from a geotechnical standpoint, provided the recommendations presented in
the following sections are adopted and incorporated into the project plans and
specifications.
The following sections provide recommendations for the proposed site development.
The civil and/or structural engineer should use this information during the planning and
design of the proposed construction. Once the plans and details have been prepared, they
should be forwarded to this office for review and comment.
The key aspects of the site, which will need to be considered during the design, include
the presence of undocumented fill soil, weathered upper portion of the old paralic
deposits that mantle the site, and the proposed subterranean construction adjacent to the
property lines. Due to the proposed grades associated with the subterranean
construction, it is anticipated that competent native soils will be exposed at the design
pad grades; however, any residual undocumented fill soil or slope wash deposits
exposed at finish grades should be removed and replaced with engineered fill. New
foundations are expected to be founded in competent native soils. Areas of localized
deepened foundations may be required to accomplish this. In addition, the proposed
grades near the property lines will require shoring walls to limit the potential impact on
neighboring properties and structures.
7.0 RECOMMENDATIONS
The following sections provide our recommendations for site preparation, design, and
construction of the proposed foundation systems. Once the plans and details have been
prepared, they should be forwarded to this office for review and comment.
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7.1 Site Preparation and Grading
All unsuitable materials (i.e., construction debris, plant material, etc.) encountered during
the grading phase should be removed and properly disposed of off-site to prepare the
site for the new construction.
Removals of undocumented fill and weathered paralic deposits are expected to be
accomplished with the design subterranean grades; however, as previously mentioned,
any residual undocumented fill or weathered paralic deposits exposed at finish grade
should be removed and replaced as engineered fill. Ultimately, removal depths will need
to be field verified at the time of construction.
In areas where less critical structures such as site walls, driveways, and walkway slabs
are proposed, removing and replacing all undocumented fill and slope wash deposits
with engineered fill is recommended to provide a more uniform bearing support.
Once the removal bottoms have been established, the bottoms should be scarified a
minimum of 6 inches, moisture-conditioned, and compacted 90 percent relative
compaction.
The on-site soil, less any organic debris, may be used for fill provided that it is placed in
thin lifts (not exceeding 8 inches in loose thickness). All soil should be properly moisture
conditioned and mechanically compacted to a minimum of 90 percent of the laboratory
maximum dry density per ASTM D-1557 and at/or slightly above optimum moisture
condition. The removal bottoms, fill placement, and compaction should be observed and
tested by the geotechnical consultant. Standard Guidelines for Grading are provided in
Appendix F.
7.2 Temporary Excavations
Foundation excavations, utility trenches, or other temporary vertical cuts may be
conducted in compacted engineered fill or formational soils to a maximum height of 4
feet. Any temporary cuts beyond the above height restraint could experience sloughing
or caving and, therefore, should either be shored or laid-back. Laid-back slopes should
have a maximum inclination of 1:1 (horizontal:vertical) and not exceed a vertical height of
10 feet without further input from the geotechnical consultant. In addition, no excavation
should undercut a 1:1 projection below the foundation for any existing improvements,
i.e., existing building foundations both on and off-site. Regional safety measures should
be enforced, and all excavations should be conducted in strict accordance with OSHA
guidelines.
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Excavation spoils should not be stockpiled adjacent to excavations as they can surcharge
the soils and trigger failure. In addition, proper erosion protection, including runoff
diversion, is recommended to reduce the possibility of erosion of slopes during grading
and building construction. Ultimately, it is the contractor’s responsibility to maintain safe
working conditions for persons on-site.
7.3 Foundation Recommendations
The following sections provide the soil parameters and general guidelines for foundation
design and construction. It is anticipated that all new construction will be supported by
conventional continuous and spread footings. As mentioned previously, the new
foundations should be supported on competent native soils. If additional parameters are
desired, they can be provided on request.
The foundation design parameters and guidelines provided below are “minimums” in
keeping with the current standard of practice. They do not preclude more restrictive
criteria that the governing agency or structural engineer may require. The architect or
structural engineer should evaluate the foundation configurations and reinforcement
requirements for structural loading, concrete shrinkage, and temperature stress.
7.4 Soil Design Criteria
The following separate soil design criteria are provided for the design and construction of
the conventional foundations for light building structures. The provided parameters
assume foundation embedment in competent engineered fill material with an expansion
index classification as “low.”
Conventional Foundations
Allowable bearing capacity for square or continuous footings ................................. 2,500 psf
Minimum embedment in competent engineered fill or paralic deposits......................... 24 in
Minimum width for continuous footings ........................................................................... 15 in
Minimum width for square footings ................................................................................. 2.5 ft
Note: The bearing capacity value may be increased by one-third for transient loads such
as wind and seismic. In addition, the value provided may be increased by 500 psf for
each additional foot of width or depth beyond the minimums provided. The increased
bearing capacity should not exceed 5,000 psf.
Coefficient of friction against sliding .................................................................................. 0.35
Passive resistance ..................................................... 350 psf/ft up to a maximum of 2,500 psf
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Soldier Pile Temporary Shoring (Cantilevered)
Allowable bearing capacity for temporary soldier pile shoring ................................ 8,000 psf
Note: The bearing capacity provided is a net value after down drag and concrete weight
are considered.
Minimum embedment in competent paralic deposits ........................................................ 5 ft
Note: All embedments should be verified in the field by the soil engineer prior to the
placement of reinforcing steel.
Minimum width or diameter for piles .................................................................................. 2 ft
Active pressure for the level ground surface at the top of excavation ...................... 35 psf/ft
Structural surcharge from adjacent footings ............................................ 0.50x (footing load)
Note: Apply surcharge to the portion of retaining wall below 1:1 projection from base of
overlying footing.
Passive resistance in competent paralic deposits ..................................................... 350 psf/ft
Note: Passive resistance may be applied in a tributary fashion over two pile diameters
from the elevated ground surface to the base of the pile.
7.5 Retaining Walls
Lateral Loading and Resistance Parameters
The bearing capacity and foundation dimensions provided in Section 7.4 may be followed
for retaining walls. Additional design parameters for lateral loading and resistance are
provided below:
Active earth pressure for level backfill (non-restrained walls) ................................... 35 psf/ft
At rest earth pressure for level backfill (restrained walls) .......................................... 55 psf/ft
Structural surcharge from adjacent footings ............................................ 0.50x (footing load)
Note: The active and at-rest pressures are provided, assuming importing granular soil is
used for backfill. Backfill and subdrain recommendations are provided in the following
sections.
Passive resistance in competent fill ........................................................................... 350 psf/ft
Coefficient of friction against sliding .................................................................................. 0.35
Note: The passive resistance and coefficient of friction may be used in combination if
there is a fixed structure, such as a floor slab over the toe of the retaining wall. If the two
values are combined, the passive resistance value should be reduced by one-third.
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Earthquake Loads
Seismic loading for retaining walls with level backfill should be approximated by applying
a 17 psf/ft in an inverse triangle shape where the lateral force at the bottom of the wall is
equal to zero, and the lateral force at the top of the retaining wall is equal to 17 psf times
the height of the wall. The resultant seismic load should be applied from the bottom of
the wall at 0.6 times the overall height of the wall.
The seismic loads would be in addition to the provided normal earth pressure loads
applied on the retaining walls. The structural engineer should evaluate the overall height
of the wall and apply the appropriate retaining wall loading parameters for analysis and
design.
7.6 Earthquake Design Parameters
Earthquake-resistant design parameters may be determined from the California Building
Code (2019 Edition). Based on our investigation and characterization of the site, the
following design parameters may be adopted:
Site coordinates ....................................................... Latitude: 33.16005, Longitude: -117.3544
Site classification ..................................................................................................................... D
Site coefficient Fa ................................................................................................................... 1.2
Site coefficient Fv ................................................................................................................. Null
Spectral response acceleration at short periods Ss ......................................................... 1.263
Spectral response acceleration at 1-second period S1 ................................................... .0.445
Maximum spectral response accelerations at short periods Sms................................... 1.516
Maximum spectral response accelerations at 1-second period Sm1 ................................ Null
Design spectral response accelerations at short periods Sds ........................................... 1.01
Design spectral response accelerations at 1-second period Sd1 ...................................... Null
7.7 Foundation and Retaining Wall Design Guidelines
The following guidelines are provided for assistance in designing the various foundation
elements and are based on the anticipated low expansion potential of the bearing soils.
As is always the case, where more restrictive, the structural and/or architectural design
criteria should take precedent.
Foundations - Continuous footings for the buildings should be a minimum of 24 inches
deep. Reinforcement should consist of a minimum of four No. 5 rebar; two placed at the
top and two at the bottom of the footing. All footing embedments should be verified by
the soil engineer.
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Minor movements are generally expected between the existing structure and the
proposed additions in transition areas. It is recommended that architectural detailing is
provided for the interface between the existing and new construction to mitigate the
effects of such movements. These details may include but are not limited to metal
connectors, special trim, elastic paint, or other items that will help resist or otherwise
accommodate minor movements.
Slabs-on-Grade - Interior and exterior slabs-on-grade should be a minimum of 5 inches
thick (net) and reinforced with No. 4 rebar placed at a maximum spacing of 18 inches on
center, both ways. The steel reinforcement should be placed at the midpoint or slightly
above the midpoint in the slab section. Control joints should be installed for exterior slabs
at a maximum spacing of 10 feet in each direction. Prior to the construction of slabs, the
subgrade should be moistened to approximately 12 inches in depth at least 24 hours
before placing the concrete. Exterior slabs that will abut soil or planter areas should be
constructed with a 12-inch thick by 12-inch-wide thickened edge to help mitigate lateral
moisture migration. The recommendations are considered minimums for the site soil.
All interior floor slabs should be underlain by 2 inches of clean sand followed by a
minimum 15-mil PVC vapor retarder (Stego Wrap or similar). The vapor retarder should
be further underlain by a 4-inch-thick layer of gravel or crushed rock. Also, the vapor
retarder should be properly lapped and sealed around all plumbing penetrations.
Retaining Walls - Retaining walls should be provided with a gravel subdrain system. The
drain system should start with a minimum 4-inch diameter perforated PVC Schedule 40 or
ABS pipe placed at the heel of the wall footing and below the adjacent slab level. The
pipe should be sloped at least 1 percent to a suitable outlet, such as an approved site
drainage system or off-site storm drain. The pipe should be surrounded by a gravel
backfill consisting of tamped 3/4-inch sized gravel. This gravel backfill zone should be a
minimum of 12 inches wide and should extend from slightly below the drainpipe up to
approximately 2/3 the wall height. The entire gravel section should be wrapped in a filter
cloth such as Mirafi 140 NS or similar to prevent contamination with fines. Alternatively,
walls can be drained using geo-composite panel drains that connect to a gravel sub-drain
at the heel of the wall. In addition, the wall should be properly moisture-proofed per the
project architect. See Retaining Wall Drain Details, Figure 4 in Appendix A.
Foundation and Slab Concrete - The results of the corrosion tests are pending. These
results will be provided once they become available. However, given the relative
proximity to the ocean, it is recommended that the concrete used for foundation elements
contain Type V cement. The concrete should be mixed and placed per ACI specifications.
Water should not be added to the concrete at the site, as this can reduce the mix and lead
to increased porosity and shrinkage cracking.
Proposed Memory Care and Independent Living • Ocean Street, Carlsbad, CA • FN 22-041 • February 25, 2022
- 13 -
Proper curing techniques and a reduction in mixing water can help reduce cracking and
concrete permeability. Consideration should be given to using a concrete mix that
possesses a maximum water-cement ratio of 0.5 to further reduce shrinkage cracking and
slab permeability.
It should be noted that TCI does not consult in the field of corrosion engineering. Thus,
the client project architect and engineer should evaluate the level of corrosion protection
required for the project and seek consultation from a qualified professional, as warranted.
Appurtenances - Other site appurtenances, such as planter walls, site walls, etc., can be
constructed on continuous footings. Footings for such appurtenances should be a
minimum of 18 inches deep, 12 inches wide, and minimally reinforced with four No. 4
bars, two top, and two bottom. The bearing capacity for such appurtenances is 1,500 psf.
7.8 Trench Backfill
Trench excavations for utility lines should be properly backfilled and compacted. Utilities
should be properly bedded and backfilled with clean sand or approved granular soil to a
depth of at least 1 foot over the pipe. This backfill should be uniformly watered and
compacted to a firm condition for vertical and lateral pipe support. The remainder of the
backfill may be typical on-site soil or low expansive import placed near optimum
moisture content in lifts not exceeding 8 inches in thickness and mechanically compacted
to at least 90 percent relative compaction.
7.9 Pavement
The following pavement sections are provided for the new pavements associated with the
proposed improvements. Subgrade preparation should be conducted immediately prior
to placement of the pavement section. As a minimum, the upper 12 inches of subgrade
in the area of the proposed pavement should be removed and properly re-compacted to
95 percent relative compaction and moisture-conditioned to at least 2 percent over the
optimum moisture content (per ASTM D-1557).
It is assumed that the proposed parking areas will receive light vehicle traffic, etc. The
following pavement sections are recommended based on an assumed R-value of 5 and in
accordance with the Caltrans Highway Design Manual and the Flexible Pavement
Structural Section Design Guide for California Cities and Counties (3rd edition). Concrete
pavement sections were determined utilizing the Design of Concrete Pavement for City
Streets by Portland Cement Association.
Proposed Memory Care and Independent Living • Ocean Street, Carlsbad, CA • FN 22-041 • February 25, 2022
- 14 -
Assumed Traffic
Index Assumed R-Value Surface Course Aggregate Base (Class II)
Asphalt Pavement Section - Driveway
5.0 5 3.0 inches 10.0 inches
Concrete Pavement Section - Driveway
5.0 5 6.0 inches 4.0 inches
Final pavement designs should be determined based on testing the soils exposed at the
completion of the finished grading.
Concrete should be reinforced at a minimum with No. 4 rebar at 16 inches on center, each
way, placed at the mid-point of the section. Additionally, control joints should be saw-cut
2.5 inches deep longitudinally at 10-foot maximum spacing and transversely at 10-foot
maximum spacing. The concrete should be placed in conformance with ACI standards
and have a minimum modulus of rupture of 500 psi.
Proper curing techniques and a reduction in mixing water can help reduce cracking and
concrete permeability. Consideration should be given to using a concrete mix that
possesses a maximum water-cement ratio of 0.5 to further help reduce shrinkage
cracking and slab permeability.
Aggregate base should conform to the specifications for crushed aggregate base, crushed
miscellaneous base, or processed miscellaneous base, as defined in Section 200-2 of the
“Greenbook.” Aggregate base should be compacted to at least 95 percent of maximum
dry density based on ASTM D-1557 guidelines. Asphalt concrete should conform to
“Greenbook” specifications. Asphalt concrete should be compacted to at least 95 percent
based on the Hveem unit weight.
7.10 Site Drainage
Drainage should be designed to direct surface water away from structures and onto an
approved disposal area. A minimum gradient of 2 percent should be maintained for earth
areas, with drainage directed away from slopes and towards approved swales or
collection facilities. Positive drainage should be maintained within an away gradient of at
least 5 percent for a minimum distance of 10 feet from foundations to reduce the
saturation of the building foundation soils. Where property line constraints prohibit this
distance, a 5 percent gradient to an approved drainage diversion (i.e., area drains or
swales) should be provided. Impervious surfaces within 10 feet of the building foundation
should be sloped a minimum of 2 percent away from the building. Drainage patterns
approved after grading should be maintained throughout the life of the development. In
addition, it is recommended that roof gutters be installed with downspouts tied into a
tight-lined system with an appropriate outlet.
I II II II I
I I I
l I I
Proposed Memory Care and Independent Living • Ocean Street, Carlsbad, CA • FN 22-041 • February 25, 2022
- 15 -
7.11 Plan Review and Geotechnical Observation
When the grading and foundation plans are completed, they should be reviewed by TCI
for compliance with the recommendations herein. Observation by TCI or another
company’s geotechnical representative is essential during grading and/or construction to
confirm conditions anticipated by the preliminary investigation, adjust designs to actual
field conditions, and determine that grading is conducted in general accordance with our
recommendations. In addition, all foundation excavations should be reviewed for
conformance with the plans prior to the placement of forms, reinforcement, or concrete.
Observation, testing, and engineering consulting services are provided by our firm and
should be budgeted within the cost of development.
8.0 CLOSURE
8.1 Limits of Investigation
Our investigation was performed using the skill and degree of care ordinarily exercised,
under similar circumstances, by reputable soils engineers and engineering geologists
practicing in this or similar localities. No warranty, expressed or implied, is made as to
this report's conclusions and professional advice. This report is prepared for the sole use
of our client and may not be assigned to others without the written consent of the client
and TCI.
The samples taken and used for testing, and the observations made, are believed
representative of the site conditions; however, soil and geologic conditions can vary
significantly between test excavations and surface exposures. As in most projects,
conditions revealed by construction excavations may vary with the preliminary findings.
If this occurs, the geotechnical engineer should evaluate the changed conditions and
adjust recommendations and designs as necessary.
The owner or their representative is responsible for ensuring the information and
recommendations contained herein are brought to the attention of the project architect
and engineer. Appropriate recommendations should be incorporated into the structural
plans and the necessary steps taken to see that the contractor and subcontractors carry
out such recommendations in the field.
The findings of this report are valid as of the present date. However, the conditions can
change over time, whether they are due to natural processes or the works of man. In
addition, changes in applicable or appropriate standards may occur from legislation or
the broadening of knowledge. Accordingly, the findings of this report may be invalidated
wholly or partially by changes outside of our control. This report is subject to review and
should be updated after a period of 3 years.
* * * TerraPacific Consultants, Inc. * * *
APPENDIX A
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Description of Map Units
Old paralic deposits, Unit 6 (late to middle
Pleistocene)—Mostly poorly sorted, moderately permeable,
reddish-brown, interfingered strandline, beach, estuarine
and colluvial deposits composed of siltstone, sandstone and
conglomerate. These deposits rest on the 22-23 m Nestor
terrace (Fig. 3)
Qop6
(g)
Old paralic deposits, Unit 7 (late to middle
Pleistocene)—Mostly poorly sorted, moderately permeable,
reddish-brown, interfingered strandline, beach, estuarine
and colluvial deposits composed of siltstone, sandstone and
conglomerate. These deposits rest on the 9-11 m Bird Rock
terrace (Fig. 3)
Qop7
Geologic Map
1.0 mile0
Oceanside Quadrangle
Compiled by
Michael P. Kennedy and Siang S. Tan
2005
1. U.S. Geological Survey, Department of Earth Sciences, University of California, Riverside
4010 Morena BoulevardSuite 108San Diego CA 92117858-521-1190 Figure 3Ocean Street MemoryCare
File No. 22-041
February 2022
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NOT TO SCALE
Retaining Wall
Drain Details
4010 Morena BoulevardSuite 108San Diego CA 92117858-521-1190
Ocean Street Memory
Care
File No. 22-041
February 2022
½ - ¾-inch crushed rock wrappedin filter fabric (Mirafi 140N orapproved alternate). Tamp gravelin maximum 10” thick lifts.
4-inch diameter PVCperforated pipe
ROCK & FABRIC
ALTERNATIVE
PANEL DRAIN
ALTERNATIVE
4-inch diameter PVCperforated pipe
Damp-proofing or water-proofing(designed by others)
3 cu. ft. per linear foot ofminus ¾-inch crushed rockwrapped in filter fabric (140 Nor approved alternate)
Geocomposite panel drain should consist of Miradrain 6000, Mirafi G100N, J-Drain 400, or approved similar product.4)
Drain installation should be observed by the geotechnical consultant prior to backfilling.5)
3) Filter fabric should consist of Mirafi 140N or similar approved fabric. Filter fabric should be overlapped at least
6-inches.
2) Perforated pipe should outlet through to a solid pipe at maximum 25 foot centers to a free gravity outfall.
Perforated pipe and outlet pipe should have a fall of at least 1%.
1) The wall drain is intended to reduce water buildup by collecting water from a top-down source to help relieve
hydrostatic pressure on the wall. If interior living space abuts the retaining wall or water infiltration is otherwise
a concern, then the owner or builder should assign a qualified professional to evaluate the wall design.
Modifications to the design may include re-location of the subdrain to the heel of the wall.
NOTES:
Geocomposite panel drain(Miradrain 6000 or approvedalternative. See Note 3 below.
2/3wallheight
Damp-proofing or water-proofing(designed by others)
Compacted granular import backfill;placed in 8” maximum looselift thickness and compactedto 90% w/ moisture at orslightly above optimum.
Compacted granular import backfill;placed in 8” maximum looselift thickness and compactedto 90% w/ moisture at orslightly above optimum.
EXISTING FILL
OR BEDROCK
EXISTING FILL
OR BEDROCK
APPENDIX B
References
REFERENCES
1) American Society of Civil Engineers, Minimum Design Loads for Buildings and
Other Structures, ASCE Standard 7-05, 2006.
2) American Society for Testing and Materials, Annual Books of ASTM Standards,
Section 4, Construction, Volume 04.08 Soil and Rock (I): D 420 – D 4914, West
Conshohocken, PA, 2008.
3) Bing/Google Maps, Site Location Map for property with APNs 203-144-0400, 0500,
0600, 0700 and 0800, Carlsbad CA 92014.
4) Blake, T.F., EQFAULT, EQSEARCH, FRISK: Computer Programs for Estimation of
Peak Horizontal Acceleration from Southern California Historic Earthquakes, 2000.
5) California Building Standards Commission, California Building Code, 2019 Edition.
6) California Department of Conservation, Fault-Rupture Hazard Zones in California,
Alquist-Priolo Earthquake Fault Zoning Act with Index to Earthquake Fault Zones
Maps, Special Publication 42, California Geological Survey, Interim Revision 2007.
7) California Geological Survey, Guidelines for Evaluating and Mitigating Seismic
Hazards in California, Special Publication 117, 2008.
8) California Geological Survey, Probabilistic Seismic Hazards Mapping Ground
Motion Page, California Geological Survey website.
9) City of San Diego, Guidelines for Geotechnical Reports, 2018.
10) Ocean Street - Memory Care and Independent Living - Concept Plans, Front porch-
Cuningham Ocean Street, Carlsbad, CA 92008.
11) Harden, D., California Geology, 1997.
12) Jennings, C.W., 1994, Fault Activity Map of California and Adjacent Areas,
California Division of Mines and Geology, Map No. 6, Scale 1:750,000.
13) Kennedy, Michael P. and Peterson, G.L., 2001 Re-Print, Geology of San Diego
Metropolitan Area, California, California Department of Conservatory Division of
Mines and Geology, Bulletin 200.
14) Kennedy, M.P. and Tan, S.S., 2008, Geologic Map of the San Diego 30’ by 60’
Quadrangle, California, California Geological Survey, Regional Geologic Map
Series, 1:100,000 Scale, Map No. 3, San Diego Quadrangle.
15) Krier, Robert, July 6, 2005, Wave Warning, Tsunami Risk on San Diego Coast
Could Be Higher Than Previously Thought, San Diego Union Tribune Article.
II
REFERENCES
16) Leyendecker, Frankel, and Rukstales, Earthquake Ground Motion Parameters
Version 5.0.9a, dated November 13, 2009.
17) Norris, Robert M. and Webb, Robert W., 1976, Geology of California, John Wiley &
Sons.
18) Treiman, J.A., The Rose Canyon Fault Zone, Southern California, California
Department of Conservation, Division of Mines and Geology, DMG open-file report
93-02, 1993.
19) United States Department of Agriculture, Soil Quality Indicators, June 2008.
20) United States Geological Survey, California-Nevada Active Faults Index Map,
http://quake.wr.usgs.gov/info/faultmaps/index.html.
21) United States Geological Survey, Earthquake Hazards Program, Seismic Hazards
Maps and Data, http://earthquake.usgs.gov/hazards.
22) United States Geological Survey, Earthquake Hazards Program, 2010 Fault Activity
Map of California, http://www.quake.ca.gov/gmaps/FAM/faultactivitymap.html.
23) Wesnousky, S.G., 1986, Earthquakes, Quaternary Faults and Seismic Hazard in
California, Journal of Geophysical Research, Vol. 91, No. B12, pp. 2587-2631.
APPENDIX C
Subsurface Excavation Logs
Drilling Company:
DESCRIPTION & REMARKSLithologyDe
p
t
h
(f
t
)
Project No:
Project Name:
Location:
Sample Method:
Date:
Logged By:
Instrumentation:
Driller:
22-041
Ocean Street Memory Care
Beech Ave and Ocean Street
Modified California Sampler
2-17-22
O. Brambila
None installed
Native Drilling
F.S.Elevation:
Steve
Drill Rig Type:
Hammer Wt. & Drop:
L.A.R. Solid Flight
140 lbs. for 30"
(%
)
Mo
i
s
t
u
r
e
(p
c
f
)
(6
"
,
1
2
"
,
1
8
"
)
Co
u
n
t
s
Bl
o
w
Ty
p
e
Sa
m
p
l
e
Subsurface Boring Log
B-1Boring No:
US
C
S
Dr
y
D
e
n
s
i
t
y
Total Depth:15.0'Boring
Page 1 of 1
B-1Water:No
Caving:No
Hole Diameter:5"
@2.0', Slightly moist, medium dense
FILL: From 0.0', Silty sand, light orange brown, moist, loose
OLD PARALIC DEPOSITS (QOP6-7): From 4.0', Silty sandstone, light orange brown, slightly moist, dense, slight porosity
From 9.0', Sandstone, orange brown, slightly moist, dense, friable, medium grained, poorly graded
Ring
Ring
Ring
6/7/13
6/14/24
10/12/20
108.6
111.8
--
0
5
10
15
20
25
30
35
40
2.0
5.4
--
0
5
10
15
20
25
30
35
40
Drilling Company:
DESCRIPTION & REMARKSLithologyDe
p
t
h
(f
t
)
Project No:
Project Name:
Location:
Sample Method:
Date:
Logged By:
Instrumentation:
Driller:
22-041
Ocean Street Memory Care
Beech Ave and Ocean Street
Modified California Sampler
2-17-22
O. Brambila
None installed
Native
FSElevation:
Steve
Drill Rig Type:
Hammer Wt. & Drop:
L.A.R. Flight Auger
140 lbs. for 30"
(%
)
Mo
i
s
t
u
r
e
(p
c
f
)
(6
"
,
1
2
"
,
1
8
"
)
Co
u
n
t
s
Bl
o
w
Ty
p
e
Sa
m
p
l
e
Subsurface Boring Log
B-2Boring No:
US
C
S
Dr
y
D
e
n
s
i
t
y
Total Depth:11.5'Boring
Page 1 of 1
B-2Water:No
Caving:No
Hole Diameter:5"
FILL: From 0.0', Silty sand, orange brown, moist to slightly moist, loose
OLD PARALIC DEPOSITS (QOP6-7): From 2.5', Silty sandstone, light red brown,
slightly moist, dense, slightly weathered
From 6.0', Sandstone, red brown, slightly moist, dense, fine to medium dense, trace of
clay
From 8.0', Silty sandstone, light red brown, slightly moist, dense, friable
Ring
Ring
Ring
5/14/23
17/17/18
11/12/15
--
--
--
0
5
10
15
20
25
30
35
40
--
--
--
0
5
10
15
20
25
30
35
40
Drilling Company:
DESCRIPTION & REMARKSLithologyDe
p
t
h
(f
t
)
Project No:
Project Name:
Location:
Sample Method:
Date:
Logged By:
Instrumentation:
Driller:
22-041
Ocean Street Memory Care
Beech Ave and Ocean Street
Modified California Sampler
2-17-22
O. Brambila
None installed
Native
FSElevation:
Steve
Drill Rig Type:
Hammer Wt. & Drop:
L.A.R. Solid Flight Auger
140 lbs. for 30"
(%
)
Mo
i
s
t
u
r
e
(p
c
f
)
(6
"
,
1
2
"
,
1
8
"
)
Co
u
n
t
s
Bl
o
w
Ty
p
e
Sa
m
p
l
e
Subsurface Boring Log
B-3Boring No:
US
C
S
Dr
y
D
e
n
s
i
t
y
Total Depth:21.5'Boring
Page 1 of 1
B-3Water:No
Caving:No
Hole Diameter:5"
FILL: From 0.0', Silty sand, orange brown to red brown, moist to slightly moist, loose
OLD PARALIC DEPOSITS (QOP6-7): From 2.5', Silty sandstone, red brown, slightly
moist, medium dense to dense, slightly weathered, slight porosity
From 9.0', Sandstone, light orange brown, slightly moist, dense, fine to medium grained, friable
From 16.0', Sandstone, light tan brown, slightly moist, dense, friable, medium grained
Bulk
Ring
Ring
Ring
--
22/26/29
12/14/17
9/10/13
--
--
--
--
0
5
10
15
20
25
30
35
40
--
--
--
--
0
5
10
15
20
25
30
35
40
Drilling Company:
DESCRIPTION & REMARKSLithologyDe
p
t
h
(f
t
)
Project No:
Project Name:
Location:
Sample Method:
Date:
Logged By:
Instrumentation:
Driller:
22-041
Ocean Street Memory Care
Beech Ave and Ocean Street
Modified California Sampler
2-17-22
O. Brambila
None installed
Native
FSElevation:
Steve
Drill Rig Type:
Hammer Wt. & Drop:
L.A.R. Solid Flight Auger
140 lbs. for 30"
(%
)
Mo
i
s
t
u
r
e
(p
c
f
)
(6
"
,
1
2
"
,
1
8
"
)
Co
u
n
t
s
Bl
o
w
Ty
p
e
Sa
m
p
l
e
Subsurface Boring Log
B-4Boring No:
US
C
S
Dr
y
D
e
n
s
i
t
y
Total Depth:11.5'Boring
Page 1 of 1
B-4Water:No
Caving:No
Hole Diameter:5"
FILL: From 0.0', Silty sand, light orange brown to red brown, moist, loose
OLD PARALIC DEPOSITS (QOP6-7): From 3.0', Silty sandstone, orange brown, slightly
moist, medium dense, slightly weathered, friable
From 9.0', Silty sandstone, red brown, slightly moist, dense, friable
Ring
Ring
14/15/17
18/22/30
--
--
0
5
10
15
20
25
30
35
40
--
--
0
5
10
15
20
25
30
35
40
Drilling Company:
DESCRIPTION & REMARKSLithologyDe
p
t
h
(f
t
)
Project No:
Project Name:
Location:
Sample Method:
Date:
Logged By:
Instrumentation:
Driller:
22-041
Ocean Street Memory Care
Beech Ave and Ocean Street
Modified California Sampler
2-17-22
O. Brambila
None installed
Native
FSElevation:
Steve
Drill Rig Type:
Hammer Wt. & Drop:
L.A.R. Solid Flight Auger
140 lbs. for 30"
(%
)
Mo
i
s
t
u
r
e
(p
c
f
)
(6
"
,
1
2
"
,
1
8
"
)
Co
u
n
t
s
Bl
o
w
Ty
p
e
Sa
m
p
l
e
Subsurface Boring Log
B-5Boring No:
US
C
S
Dr
y
D
e
n
s
i
t
y
Total Depth:9.0 Boring
Page 1 of 1
B-5Water:No
Caving:No
Hole Diameter:5"
FILL: From 0.0', Silty sand, light orange brown, moist, loose
OLD PARALIC DEPOSITS (QOP6-7): From 2.5', Silty sandstone, orange brown, slightly
moist, dense, slightly weathered Ring
SPT
6/9/13
8/8/10
--
--
0
5
10
15
20
25
30
35
40
--
--
0
5
10
15
20
25
30
35
40
Drilling Company:
DESCRIPTION & REMARKSLithologyDe
p
t
h
(f
t
)
Project No:
Project Name:
Location:
Sample Method:
Date:
Logged By:
Instrumentation:
Driller:
22-041
Ocean Street Memory Care
Beech Ave and Ocean Street
Modified California Sampler
2-17-22
O. Brambila
None installed
Native
FSElevation:
Steve
Drill Rig Type:
Hammer Wt. & Drop:
L.A.R. Solid Flight Auger
140 lbs. for 30"
(%
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Subsurface Boring Log
B-6Boring No:
US
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Total Depth:36.5'Boring
Page 1 of 1
B-6Water:No
Caving:No
Hole Diameter:5"
@30.0', Some boulders
@32.0', Groundwater
FILL: From 0.0', Silty sand, light orange brown, moist, loose
OLD PARALIC DEPOSIT (QOP6-7): From 2.0', Silty sandstone, red brown, slightly
moist, medium dense, slightly weathered
From 8.0', Sandstone, orange brown, slightly moist, dense, friable
From 12.0', Silty sandstone, orange brown, slightly moist, dense, fine to medium
grained, trace of clay
From 16.0', Sandstone, pale brown, slightly moist, dense, poorly graded, friable
From 26.0', Sandstone, pale brown, moist, dense, gravel and cobbles
From 33.0', Sandstone, light gray to pale brown, wet, dense
Ring
Ring
9/13/17
7/18/34
--
--
0
5
10
15
20
25
30
35
40
--
--
0
5
10
15
20
25
30
35
40
APPENDIX D
Laboratory Test Results
CTM422 CTM 417
Sample Sample Chloride Sulfate Passing Dry Moisture Hydro Normal Peak Peak
Location Depth Type Content Content No. 200 Density Content Response (%) Stree (PSF)φ c
B-1 3.0' Ring -- ----108.6 2.0 -- -- 42.0 10.0
B-1 8.0' Ring -- ----111.8 5.4 -- -- -- --
B-1 0-6.0' LB Pending Pending 20.4 -- -- -- -- -- --
B-6 35.0' Ring -- ------ -- -- -- 46.0 310.0
B-2 5.0' Ring -- ------ -- -0.66 3000.0 -- --
B-4 10.0' Ring -- ------ -- -0.20 3000.0 -- --
Ocean Front Memory Care
Summary of Laboratory Test Results
F.N.: 22-041
ASTM D 4546Corrosivity Series ASTM D 422 ASTM D 2937 ASTM D 3080Sample Location
I
File Name:
DIRECT SHEAR TEST File No.:
Laboratory Report Date:
Technician:
Peak Ultimate
42 40
10 5
TerraPacific Consultants Inc. 4010 Morena Boulevard, Suite 108, San Diego, CA 92117 / Phone: (858) 521-1190 Fax: (858) 521-1199
Ocean Front Memory Care
Friction Angle Φ' (deg)
Cohesion C' (psf)
22-041
2/21/2022
JMS
Sample No.&
Location:B-1 @ 3.0'
Specimen
Preparation:Inundated
Sample Type:
Soil Description: Medium Brown Sand
Intact
0 500 1000 1500 2000 2500 3000 3500 4000
0
500
1000
1500
2000
2500
3000
3500
4000
Peak Strength Test
Results
Ultimate Strength Test
Results
0
500
1000
1500
2000
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500 PSF
1000 PSF
2000 PSF
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Normal Stress (PSF)
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File Name:
DIRECT SHEAR TEST File No.:
Laboratory Report Date:
Technician:
Peak Ultimate
46 36
310 300
TerraPacific Consultants Inc. 4010 Morena Boulevard, Suite 108, San Diego, CA 92117 / Phone: (858) 521-1190 Fax: (858) 521-1199
Ocean Front Memory Care
Friction Angle Φ' (deg)
Cohesion C' (psf)
22-041
2/21/2022
JMS
Sample No.&
Location:B-6 @ 35.0'
Specimen
Preparation:Inundated
Sample Type:
Soil Description: Grey Sand
Intact
0 500 1000 1500 2000 2500 3000 3500 4000
0
500
1000
1500
2000
2500
3000
3500
4000
Peak Strength Test
Results
Ultimate Strength Test
Results
0
500
1000
1500
2000
2500
3000
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APPENDIX E
Summary of Active Faults
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APPENDIX F
Standard Grading Guidelines
STANDARD GUIDELINES FOR GRADING PROJECTS
TABLE OF CONTENTS
Page
GENERAL ............................................................................................................................... F-1
DEFINITIONS OF TERMS ...................................................................................................... F-1
OBLIGATIONS OF PARTIES ................................................................................................. F-4
SITE PREPARATION .............................................................................................................. F-4
SITE PROTECTION ................................................................................................................ F-5
EXCAVATIONS ...................................................................................................................... F-6
Unsuitable Materials ................................................................................................. F-6
Cut Slopes .................................................................................................................. F-6
Pad Areas ................................................................................................................... F-6
COMPACTED FILL ................................................................................................................. F-7
Placement .................................................................................................................. F-7
Moisture ..................................................................................................................... F-8
Fill Material ................................................................................................................ F-8
Fill Slopes ................................................................................................................ F-10
Off-Site Fill ............................................................................................................... F-11
DRAINAGE ........................................................................................................................... F-11
STAKING ............................................................................................................................. F-11
SLOPE MAINTENANCE ...................................................................................................... F-12
Landscape Plants ..................................................................................................... F-12
Irrigation................................................................................................................... F-12
Maintenance ............................................................................................................ F-12
Repairs ..................................................................................................................... F-12
TRENCH BACKFILL ............................................................................................................. F-13
STATUS OF GRADING........................................................................................................ F-13
Standard Guidelines
for Grading Projects
F-1
GENERAL
The guidelines contained herein and the standard details attached hereto represent this firm's
standard recommendations for grading and other associated operations on construction
projects. These guidelines should be considered a portion of the project specifications.
All plates attached hereto shall be considered as part of these guidelines.
The Contractor should not vary from these guidelines without prior recommendation by the
Geotechnical Consultant and the approval of the Client or his authorized representative.
Recommendation by the Geotechnical Consultant and/or Client should not be considered to
preclude requirements for approval by the controlling agency prior to the execution of any
changes.
These Standard Grading Guidelines and Standard Details may be modified and/or superseded
by recommendations contained in the text of the preliminary geotechnical report and/or
subsequent reports.
If disputes arise out of the interpretation of these grading guidelines or standard details, the
Geotechnical Consultant shall provide the governing interpretation.
DEFINITIONS OF TERMS
ALLUVIUM - Unconsolidated soil deposits resulting from flow of water, including sediments
deposited in river beds, canyons, flood plains, lakes, fans and estuaries.
AS-GRADED (AS-BUILT) - The surface and subsurface conditions at completion of grading.
BACKCUT - A temporary construction slope at the rear of earth retaining structures such as
buttresses, shear keys, stabilization fills or retaining walls.
BACKDRAIN - Generally a pipe and gravel or similar drainage system placed behind earth
retaining structures such buttresses, stabilization fills, and retaining walls.
BEDROCK - Relatively undisturbed formational rock, more or less solid, either at the surface
or beneath superficial deposits of soil.
BENCH - A relatively level step and near vertical rise excavated into sloping ground on which
fill is to be placed.
BORROW (Import) - Any fill material hauled to the project site from off-site areas.
BUTTRESS FILL - A fill mass, the configuration of which is designed by engineering
calculations to retain slope conditions containing adverse geologic features. A buttress is
generally specified by minimum key width and depth and by maximum backcut angle. A
buttress normally contains a back-drainage system.
CIVIL ENGINEER - The Registered Civil Engineer or consulting firm responsible for
preparation of the grading plans, surveying and verifying as-graded topographic conditions.
CLIENT - The Developer or his authorized representative who is chiefly in charge of the
project. He shall have the responsibility of reviewing the findings and recommendations
made by the Geotechnical Consultant and shall authorize the Contractor and/or other
consultants to perform work and/or provide services.
Standard Guidelines
for Grading Projects
F-2
COLLUVIUM - Generally loose deposits usually found near the base of slopes and brought
there chiefly by gravity through slow continuous downhill creep (also see Slope Wash).
COMPACTION - Densification of man-placed fill by mechanical means.
CONTRACTOR - A person or company under contract or otherwise retained by the Client to
perform demolition, grading and other site improvements.
DEBRIS - All products of clearing, grubbing, demolition, contaminated soil materials
unsuitable for reuse as compacted fill and/or any other material so designated by the
Geotechnical Consultant.
ENGINEERING GEOLOGIST - A licensed Engineering Geologist who applies scientific
methods, engineering and geologic principles and professional experience to the acquisition,
interpretation and use of knowledge of materials of the earth's crust for the evaluation of
engineering problems. Geotechnical Engineering encompasses many of the engineering
aspects of soil mechanics, rock mechanics, geology, geophysics, hydrology and related
sciences.
ENGINEERED FILL - A fill of which the Geotechnical Consultant or his representative, during
grading, has made sufficient tests to enable him to conclude that the fill has been placed in
substantial compliance with the recommendations of the Geotechnical Consultant and the
governing agency requirements.
EROSION - The wearing away of the ground surface as a result of the movement of wind
and/or water.
EXCAVATION - The mechanical removal of earth materials.
EXISTING GRADE - The ground surface configuration prior to grading.
FILL - Any deposits of soil, rock, soil-rock blends or other similar materials placed by man.
FINISH GRADE - The ground surface configuration at which time the surface elevations
conform to the approved plan.
GEOFABRIC - Any engineering textile utilized in geotechnical applications including subgrade
stabilization and filtering.
GEOLOGIST - A representative of the Geotechnical Consultant educated and trained in the
field of geology.
GEOTECHNICAL CONSULTANT - The Geotechnical Engineering and Engineering Geology
consulting firm retained to provide technical services for the project. For the purpose of these
specifications, observations by the Geotechnical Consultant include observations by the Soil
Engineer, Geotechnical Engineer, Engineering Geologist and those performed by persons
employed by and responsible to the Geotechnical Consultants.
GEOTECHNICAL ENGINEER - A licensed Geotechnical Engineer or Civil Engineer who applies
scientific methods, engineering principles and professional experience to the acquisition,
interpretation and use of knowledge of materials of the earth's crust for the evaluation of
engineering problems. Geotechnical Engineering encompasses many of the engineering
aspects of soil mechanics, rock mechanics, geology, geophysics, hydrology and related
sciences.
Standard Guidelines
for Grading Projects
F-3
GRADING - Any operation consisting of excavation, filling or combinations thereof and
associated operations.
LANDSLIDE DEBRIS - Material, generally porous and of low density, produced from instability
of natural or man-made slopes.
MAXIMUM DENSITY - Standard laboratory test for maximum dry unit weight. Unless
otherwise specified, the maximum dry unit weight shall be determined in accordance with
ASTM Method of Test D 1557-09.
OPTIMUM MOISTURE - Soil moisture content at the test maximum density.
RELATIVE COMPACTION - The degree of compaction (expressed as a percentage) of dry unit
weight of a material as compared to the maximum dry unit weight of the material.
ROUGH GRADE - The ground surface configuration at which time the surface elevations
approximately conform to the approved plan.
SITE - The particular parcel of land where grading is being performed.
SHEAR KEY - Similar to buttress, however, it is generally constructed by excavating a slot
within a natural slope in order to stabilize the upper portion of the slope without grading
encroaching into the lower portion of the slope.
SLOPE - An inclined ground surface the steepness of which is generally specified as a ratio of
horizontal:vertical (e.g., 2:1).
SLOPE WASH - Soil and/or rock material that has been transported down a slope by action of
gravity assisted by runoff water not confined by channels (also see Colluvium).
SOIL - Naturally occurring deposits of sand, silt, clay, etc., or combinations thereof.
SOIL ENGINEER - Licensed Geotechnical Engineer or Civil Engineer experienced in soil
mechanics (also see Geotechnical Engineer).
STABILIZATION FILL - A fill mass, the configuration of which is typically related to slope
height and is specified by the standards of practice for enhancing the stability of locally
adverse conditions. A stabilization fill is normally specified by minimum key width and depth
and by maximum backcut angle. A stabilization fill may or may not have a back drainage
system specified.
SUBDRAIN - Generally a pipe and gravel or similar drainage system placed beneath a fill in
the alignment of canyons or former drainage channels.
SLOUGH - Loose, non-compacted fill material generated during grading operations.
TAILINGS – Non-engineered fill which accumulates on or adjacent to equipment haul-roads.
TERRACE - Relatively level step constructed in the face of graded slope surface for drainage
control and maintenance purposes.
TOPSOIL - The presumable fertile upper zone of soil which is usually darker in color and
loose.
WINDROW - A string of large rocks buried within engineered fill in accordance with guidelines
set forth by the Geotechnical Consultant.
Standard Guidelines
for Grading Projects
F-4
OBLIGATIONS OF PARTIES
The Geotechnical Consultant should provide observation and testing services and should
make evaluations in order to advise the Client on geotechnical matters. The Geotechnical
Consultant should report his findings and recommendations 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 should be 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, earthwork in accordance with the project plans, specifications and controlling
agency requirements. During grading, the Contractor or his authorized representative should
remain on-site. Overnight and on days off, the Contractor should remain accessible.
SITE PREPARATION
The Client, prior to any site preparation or grading, should arrange and attend a meeting
among the Grading Contractor, the Design Engineer, the Geotechnical Consultant,
representatives of the appropriate governing authorities as well an any other concerned
parties. All parties should be given at least 48 hours notice.
Clearing and grubbing should consist of the removal of vegetation such as brush, grass,
woods, stumps, trees, roots 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 re-routing
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.
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.
Standard Guidelines
for Grading Projects
F-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.
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
more restrictive requirements by 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 can not be avoided,
pumps should be kept on hand to continually remove water during periods of rainfall.
During periods of rainfall, plastic sheeting should be kept reasonably accessible to prevent
unprotected slopes from becoming saturated. Where necessary during periods of rainfall, the
Contractor should install check dams, desilting basins, riprap, sand bags or other devices or
methods necessary to control erosion and provide safe conditions.
During periods of rainfall, the Geotechnical Consultant should be kept informed by the
Contractor as to the nature of remedial or preventative work being performed (e.g., pumping,
placement of sandbags or plastic sheeting, other labor, dozing, etc.).
Following periods of rainfall, the Contractor should contact the Geotechnical Consultant and
arrange a walk-over of the site in order to visually assess rain related damage. The
Geotechnical Consultant may also recommend excavations and testing in order to aid in his
assessments. At the request of the Geotechnical Consultant, the Contractor shall make
excavations in order to evaluate the extent of rain related damage.
Rain related damage should be considered to include, but may not be limited to, erosion,
silting, saturation, swelling, structural distress and other adverse conditions identified by the
Geotechnical Consultant. Soil adversely affected should be classified as Unsuitable Materials
and should be subject to over-excavation and replacement with compacted fill or other
remedial grading as recommended by the Geotechnical Consultant.
Relatively level areas, where saturated soils and/or erosion gullies exist to depths of greater
than 1-foot, should be over-excavated to unaffected, competent material. Where less than 1-
foot in depth, unsuitable materials may be processed in-place to achieve near optimum
moisture conditions, then thoroughly recompacted in accordance with the applicable
specifications. If the desired results are not achieved, the affected materials should be over-
excavated, then replaced in accordance with the applicable specifications.
In slope areas, where saturated soil and/or erosion gullies exist to depths of greater than 1
Standard Guidelines
for Grading Projects
F-6
foot, they should be over-excavated and replaced as compacted fill in accordance with the
applicable specifications. Where affected materials exist to depths of 1 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 over-
excavated and replaced as compacted fill in accordance with the slope repair
recommendations herein. As field conditions dictate, other slope repair procedures may be
recommended by the Geotechnical Consultant.
EXCAVATIONS
Unsuitable Materials
Materials which 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 non-engineered or otherwise deleterious fill materials.
Material identified by the Geotechnical Consultant as unsatisfactory due to its moisture
conditions should be over-excavated, watered or dried, as needed, and thoroughly blended to
a uniform near optimum moisture condition (per Moisture guidelines presented herein) prior
to placement as compacted fill.
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).
If excavations for cut slopes expose loose, cohesionless, significantly fractured or otherwise
unsuitable material, over-excavation and replacement of the unsuitable materials with a
compacted stabilization fill should be accomplished as recommended by the Geotechnical
Consultant. Unless otherwise specified by the Geotechnical Consultant, stabilization fill
construction should conform to the requirements of the Standard Details.
The Geotechnical Consultant should review cut slopes during excavation. The Geotechnical
Consultant should be notified by the contractor prior to beginning slope excavations.
If, during the course of grading, adverse or potentially adverse geotechnical conditions are
encountered which were not anticipated in the preliminary report, the Geotechnical
Consultant should explore, analyze and make recommendations to treat these problems.
When 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-cut.
Pad Areas
All lot pad areas, including side yard terraces, above stabilization fills or buttresses should be
over-excavated to provide for a minimum of 3-feet (refer to Standard Details) of compacted
fill over the entire pad area. Pad areas with both fill and cut materials exposed and pad areas
containing both very shallow (less than 3-feet) and deeper fill should be over-excavated to
provide for a uniform compacted fill blanket with a minimum of 3-feet in thickness (refer to
Standard Details).
Cut areas exposing significantly varying material types should also be over-excavated to
Standard Guidelines
for Grading Projects
F-7
provide for at least a 3-foot thick compacted fill blanket. Geotechnical conditions may require
greater depth of over-excavation. The actual depth should be delineated by the Geotechnical
Consultant during grading.
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 and/or an appropriate
pad gradient. A gradient in soil areas away from the top-of-slopes of 2 percent or greater is
recommended.
COMPACTED FILL
All fill materials should be compacted as specified below or by other methods specifically
recommended by the Geotechnical Consultant. Unless otherwise specified, the minimum
degree of compaction (relative compaction) should be 90 percent of the laboratory maximum
density.
Placement
Prior to placement of compacted fill, the Contractor should request a review by the
Geotechnical Consultant of the exposed ground surface. Unless otherwise recommended,
the exposed ground surface should then be scarified (6-inches minimum), watered or dried as
needed, thoroughly blended to achieve near optimum moisture conditions, then thoroughly
compacted to a minimum of 90 percent of the maximum density. The review by the
Geotechnical Consultant should not be considered to preclude requirements of inspection
and approval by the governing agency.
Compacted fill should be placed in thin horizontal lifts not exceeding 8-inches in loose
thickness prior to compaction. Each lift should be watered or dried as needed, thoroughly
blended to achieve near optimum moisture conditions then 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. If necessary, excavation equipment should
be "shut down" temporarily in order to permit proper compaction of fills. Earth moving
equipment should only be considered a supplement and not substituted for conventional
compaction equipment.
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 6-foot wide
benches and minimum of 4-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
subsequent to keying and benching until the area has been reviewed by the Geotechnical
Consultant.
Material generated by the benching operation should be moved sufficiently away from the
bench area to allow for the recommended review of the horizontal bench prior to placement
of fill. Typical keying and benching details have been included within the accompanying
Standard Details.
Within a single fill area where grading procedures dictate two or more separate fills,
Standard Guidelines
for Grading Projects
F-8
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.
Fill should be tested for compliance with the recommended relative compaction and moisture
conditions. Field density testing should conform to ASTM Method of Test D 1556-07, and/or
D 6938-10. Tests should be provided for about every 2 vertical feet or 1,000 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.
The Contractor should assist the Geotechnical Consultant and/or his representative by
digging test pits for removal determinations and/or for testing compacted fill.
As recommended by the Geotechnical Consultant, the Contractor should "shut down" or
remove grading equipment from an area being tested.
The Geotechnical Consultant should maintain a plan with estimated locations of field tests.
Unless the client provides for actual surveying of test locations, the estimated locations by the
Geotechnical Consultant should only be considered rough estimates and should not be
utilized for the purpose of preparing cross sections showing test locations or in any case for
the purpose of after-the-fact evaluating of the sequence of fill placement.
Moisture
For field testing purposes, "near optimum" moisture will vary with material type and other
factors including compaction procedures. "Near optimum" may be specifically recommended
in Preliminary Investigation Reports and/or may be evaluated during grading.
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,
watered or dried as needed, thoroughly blended to near-optimum moisture conditions, then
recompacted to a minimum of 90 percent of laboratory maximum dry density. Where wet or
other dry or other unsuitable materials exist to depths of greater than 1 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.
Fill Material
Excavated on-site 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.
Where import materials are required for use on-site, the Geotechnical Consultant should be
notified at least 72 hours in advance of importing, in order to sample and test materials from
proposed borrow sites. No import materials should be delivered for use on-site without prior
sampling and testing by Geotechnical Consultant.
Where oversized rock or similar irreducible material is generated during grading, it is
Standard Guidelines
for Grading Projects
F-9
recommended, where practical, to waste such material off-site or on-site in areas designated
as "nonstructural rock disposal areas". Rock placed in disposal areas should be placed with
sufficient fines to fill voids. The rock should be compacted in lifts to an unyielding condition.
The disposal area should be covered with at least 3 feet of compacted fill which is free of
oversized material. The upper 3 feet should be placed in accordance with the guidelines for
compacted fill herein.
Rocks 8 inches in maximum dimension and smaller may be utilized within the compacted fill,
provided they are placed in such a manner that nesting of the rock is avoided. Fill should be
placed and thoroughly compacted over and around all rock. The amount of rock should not
exceed 40 percent by dry weight passing the 3/4-inch sieve size. The 12-inch and 40 percent
recommendations herein may vary as field conditions dictate.
During the course of grading operations, rocks or similar irreducible materials greater than 8-
inches maximum dimension (oversized material) may be generated. These rocks should not
be placed within the compacted fill unless placed as recommended by the Geotechnical
Consultant.
Where rocks or similar irreducible materials of greater than 8 inches but less than 4 feet of
maximum dimension are generated during grading, or otherwise desired to be placed within
an engineered fill, special handling in accordance with the accompanying Standard Details is
recommended. Rocks greater than 4 feet should be broken down or disposed off-site. Rocks
up to 4 feet maximum dimension should be placed below the upper 10 feet of any fill and
should not be closer than 20-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, over-excavated 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 that
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. Material that is
considered unsuitable by the Geotechnical Consultant should not be utilized in the compacted
fill.
During grading operations, placing and mixing the materials from the cut and/or borrow
areas may result in soil mixtures which possess unique physical properties. Testing may be
required of samples obtained directly from the fill areas in order to verify conformance with
the specifications. Processing of these additional samples may take two or more working
days. The Contractor may elect to move the operation to other areas within the project, or
may continue placing compacted fill pending laboratory and field test results. Should he elect
the second alternative, fill placed is done so at the Contractor's risk.
Any fill placed in areas not previously reviewed and evaluated by the Geotechnical
Consultant, and/or in other areas, without prior notification to the Geotechnical Consultant
may require removal and recompaction at the Contractor's expense. Determination of over-
excavations should be made upon review of field conditions by the Geotechnical Consultant.
Standard Guidelines
for Grading Projects
F-10
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 to
vertical).
Except as specifically recommended otherwise or as otherwise provided for in these grading
guidelines (Reference Fill Materials), compacted fill slopes should be overbuilt 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 over-excavated 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.
Although no construction procedure produces a slope free from risk of future movement,
overfilling and cutting back of slope to a compacted inner core is, given no other constraints,
the most desirable procedure. Other constraints, however, must often be considered. These
constraints may include property line situations, access, the critical nature of the development
and cost. Where such constraints are identified, slope face compaction may be attempted by
conventional construction procedures including back rolling techniques upon specific
recommendation by the Geotechnical Consultant.
As a second-best alternative for slopes of 2:1 (horizontal to vertical) or flatter, slope
construction may be attempted as outlined herein. Fill placement should proceed in thin lifts,
(i.e., 6 to 8-inch loose thickness). Each lift should be moisture conditioned and thoroughly
compacted. The desired moisture condition should be maintained and/or reestablished,
where necessary, during the period between successive lifts. Selected lifts should be tested
to ascertain that desired compaction is being achieved. 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 establish 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 exceeding 4 feet in vertical slope height or the capability
of available equipment, whichever is less, fill slopes should be thoroughly backrolled utilizing
a conventional sheeps foot-type roller. Care should be taken to maintain the desired moisture
conditions and/or reestablishing same as needed prior to backrolling. Upon achieving final
grade, the slopes should again be moisture conditioned and thoroughly backrolled. The use
of a side-boom roller will probably be necessary and vibratory methods are strongly
recommended. Without delay, so as to avoid (if possible) further moisture conditioning, the
slopes should then be grid-rolled to achieve a relatively smooth surface and uniformly
compact condition.
In order to monitor slope construction procedures, moisture and density tests will be taken at
regular intervals. Failure to achieve the desired results will likely result in a recommendation
by the Geotechnical Consultant to over-excavate the slope surfaces followed by
reconstruction of the slopes utilizing overfilling and cutting back procedures and/or further
attempt at the conventional backrolling approach. Other recommendations may also be
provided which would be commensurate with field conditions.
Standard Guidelines
for Grading Projects
F-11
Where placement of fill above a natural slope or above a cut slope is proposed, the fill slope
configuration as presented in the accompanying Standard Details should be adopted.
For pad areas above fill slopes, positive drainage should be established away from the top-of-
slope. This may be accomplished utilizing a berm and pad gradients of at least 2 percent in
soil areas.
Off-Site Fill
Off-site fill should be treated in the same manner as recommended in these specifications for
site preparation, excavation, drains, compaction, etc.
Off-site canyon fill should be placed in preparation for future additional fill, as shown in the
accompanying Standard Details.
Off-site fill subdrains temporarily terminated (up canyon) should be surveyed for future
relocation and connection.
DRAINAGE
Canyon subdrain systems specified by the Geotechnical Consultant should be installed in
accordance with the Standard Details.
Typical subdrains for compacted fill buttresses, slope stabilization or sidehill masses, should
be installed in accordance with the specifications of the accompanying Standard Details.
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, concrete swales).
For drainage over soil areas immediately away from structures (i.e., within 4 feet), a minimum
of 4 percent gradient should be maintained. Pad drainage of at least 2 percent should be
maintained over soil areas. Pad drainage may be reduced to at least 1 percent for projects
where no slopes exist, either natural or man-made, or greater than 10-feet in height and
where no slopes are planned, either natural or man-made, steeper than 2:1 (horizontal to
vertical slope ratio).
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
can be detrimental to slope stability and foundation performance.
STAKING
In all fill areas, the fill should be compacted prior to the placement of the stakes. This
particularly is important on fill slopes. Slope stakes should not be placed until the slope is
thoroughly compacted (backrolled). If stakes must be placed prior to the completion of
compaction procedures, it must be recognized that they will be removed and/or demolished
at such time as compaction procedures resume.
In order to allow for remedial grading operations, which could include over-excavations or
slope stabilization, appropriate staking offsets should be provided. For finished slope and
stabilization backcut areas, we recommend at least a 10-feet setback from proposed toes and
tops-of-cut.
Standard Guidelines
for Grading Projects
F-12
SLOPE MAINTENANCE
Landscape Plants
In order 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 would be the best party to consult regarding actual types
of plants and planting configuration.
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.
Though not a requirement, consideration should be given to the installation of near-surface
moisture monitoring control devices. Such devices can aid in the maintenance of relatively
uniform and reasonably constant moisture conditions.
Property owners should be made aware that overwatering of slopes is detrimental to slope
stability.
Maintenance
Periodic inspections of landscaped slope areas should be planned and appropriate measures
should be taken to control weeds and enhance growth of the landscape plants. Some areas
may require occasional replanting and/or reseeding.
Terrace drains and down drains should be periodically inspected and maintained free of
debris. Damage to drainage improvements should be repaired immediately.
Property owners should be made aware that burrowing animals can be detrimental to slope
stability. A preventative program should be established to control burrowing animals.
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 of time prior to landscape
planting.
Repairs
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 periods of heavy rainfall, the failure area and
currently unaffected areas should be covered with plastic sheeting to protect against
additional saturation.
In the accompanying Standard Details, appropriate repair procedures are illustrated for
superficial slope failures (i.e., occurring typically within the outer 1 foot to 3 feet of a slope
face).
Standard Guidelines
for Grading Projects
F-13
TRENCH BACKFILL
Utility 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.
Backfill of exterior and interior trenches extending below a 1:1 projection from the outer edge
of foundations should be mechanically compacted to a minimum of 90 percent of the
laboratory maximum density.
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 unless provisions
are made for a drainage system to mitigate the potential build-up of seepage forces.
STATUS OF GRADING
Prior of proceeding with any grading operation, the Geotechnical Consultant should be
notified at least two working days in advance in order to schedule the necessary observation
and testing services.
Prior to any significant expansion or cut back in the grading operation, the Geotechnical
Consultant should be provided with adequate notice (i.e., two days) in order to make
appropriate adjustments in observation and testing services.
Following completion of grading operations and/or between phases of a grading operation,
the Geotechnical Consultant should be provided with at least two working days notice in
advance of commencement of additional grading operations.
BENCHING
KEY-DIMENSION PER SOILS ENGINEER
(GENERALLY ½ SLOPE HEIGHT, 15’ MIN.)
SLOPE PER PLAN
4” DIAMETER NON-PERFORATED
PIPE LATERAL DRAIN
4” DIAMETER PERFORATED
PIPE BACKDRAIN
15’ MINIMUM
H/2
1’
2’3’
PROVIDE BACK DRAIN PER BACKDRAIN DETAIL.
AN ADDITIONAL BACKDRAIN AT MID-SLOPE WILL
BE REQUIRED FOR SLOPE IN EXCESS OF 40 FEET
HIGH.
2.0%
FIGURE 1
NOT TO SCALE
TYPICAL STABILIZATION FILL DETAIL
BENCHING
KEY-DIMENSION PER SOILS ENGINEER
SLOPE PER PLAN
4” DIAMETER NON-PERFORATED
PIPE LATERAL DRAIN
4” DIAMETER PERFORATED
PIPE BACKDRAIN
15’ MINIMUM
2.0%
H/2
1’
3’5’
PROVIDE BACK DRAIN PER BACKDRAIN DETAIL.
AN ADDITIONAL BACKDRAIN AT MID-SLOPE WILL
BE REQUIRED FOR SLOPE IN EXCESS OF 40 FEET
HIGH.
FIGURE 2
NOT TO SCALE
TYPICAL BUTTRESS FILL DETAIL
PROVIDE BACKDRAIN PER
BACKDRAIN DETAIL. AN ADDITIONAL
BACKDRAIN AT MID-SLOPE WILL BE
REQURED FOR BACK SLOPES IN EXCESS
OF 40 FEET HIGH. LOCATIONS OF
BACKDRAINS AND OUTLETS PER SOILS
ENGINEER AND/OR ENGINEERING
GEOLOGIST DURING GRADING.
COMPACTED FILL
NATURAL GROUND
“W”
BASE WIDTH “W” DETERMINED
BY SOILS ENGINEER
1 ½
1
PLANE
O
F
W
E
A
K
N
E
S
S
1 ½
1
P
R
O
P
O
S
E
D GRADING
FIGURE 3
NOT TO SCALE
TYPICAL SHEAR KEY DETAIL
/
.......... .. .. .. .. .. .. .. .. .. ...... .. ......
.. ........ .. ...... .. .. .. ..
.. ......
PROVIDE BACKDRAIN PER
BACKDRAIN DETAIL AND OUTLETS
PER SOILS ENGINEER AND/OR
ENGINEERING GEOLOGIST
DURING GRADING.
OVERBURDEN
(CREEP-PRONE)
20’ MAX.
FINAL LIMIT
OF EXCAVATION
EQUIPMENT WIDTH
(MINIMUM 15’)
2’ MIN.
TYPICAL BENCHING
SOUND BEDROCK
OVER-EXCAVATE 3’ AND
REPLACE WITH COMPACTED FILL
FINISH PAD
OVER-EXCAVATE
DAYLIGHT LINE
1
1
FIGURE 4
NOT TO SCALE
DAYLIGHT SHEAR KEY DETAIL
,:f: ... ' : ......
. :·~:.:•···················--··:•i.:-
/l
/ ···'
I
//~
······:f
.:t ............ :·r····:+
//~
10’ TYPICAL
4’ TYPICAL
REMOVE U
N
S
U
I
T
A
B
L
E
M
A
T
E
R
I
A
L
REMOVE
U
N
S
U
I
T
A
B
L
E
M
A
T
E
R
I
A
L
FILL SLOPE
FILL SLOPE
SURFACE OF FIRM
EARTH MATERIAL
SURFACE OF FIRM
EARTH MATERIAL
10’ MIN.
(INCLINED 2% MIN. INTO SLOPE)
5’ MIN.
10’ TYPICAL
4’ TYPICAL
15’ MIN
OR STABILITY EQUIVALENT
PER SOIL ENGINEER
(INCLUDING 2% MIN. INTO SLOPE)
FIGURE 5
NOT TO SCALE
BENCHING FOR COMPACTED FILL DETAIL
BENCHING FILL OVER CUT
BENCHING FILL OVER NATURAL
=r-······················:·t----
; -r---
:+,:·························:t
' • ' '
+:·························:l. ...
-----------------------------------
---
---------------------------:;:; ___ -,="------_-_---
----------------------------------.:1=.
·+.:······················:t
FINISH SURFACE SLOPE
3 FT³ MINIMUM PER LINEAL FOOT
APPROVED FILTER ROCK*
4” MINIMUM DIAMETER
SOLID OUTLET PIPE
SPACING PER SOIL
ENGINEER REQUIREMENTS
DURING GRADING
4” MINIMUM APPROVED
PERFORATED PIPE**
(PERFORATIONS DOWN)
MINIMUM 2% GRADIENT
TO OUTLET
BENCH INCLINED
TOWARD DRAIN
TYPICAL BENCHING
2% MINIMUM GRADIENT
TEMPORARY FILL LEVEL
4” MINIMUM DIAMETER
APPROVED SOLID OUTLET PIPE **
COMPACTED FILL
COMPACTED
BACKFILL
DETAIL A-A
** APPROVED PIPE TYPE
Schedule 40 polyvinyl chloride
(P.V.C.) or approved equal.
Min. crush strength 1000 PSI.
* Filter rock to meet following
specifications or approved equal.
Sieve
1"
3/4"
3/8"
No.4
No.30
No.50
No.200
% Passing
100
90-100
40-100
25-40
5-15
0-7
0-3
12”
MINIMUM
12”
MINIMUM
COVER
A
A
FIGURE 6
NOT TO SCALE
TYPICAL BACKDRAIN DETAIL
•~l ............................. ••t. ... ...
2% Min Gradient
Finish surface slope
3 ft³ Min per lineal foot approved filter rock*
T-Connection
(see detail)
Compacted fill
Typical benching
4" Min approved perforated pipe**
(perforations down min.
2% gradient to outlet)
Bench inclined toward drain 2% Min.4" Min. diameter solid outlet pipe
spaced per soil engineer requirements
during grading
2% Min Gradient
A
A'
** Approved pipe type:
Schedule 40 polyvinyl chloride
(P.V.C.) or approved equal.
Min. crush strength 1000 PSI.
* Filter rock to meet following
specifications or approved equal.
Sieve
1"
3/4"
3/8"
No.4
No.30
No.50
No.200
% Passing
100
90-100
40-100
25-40
5-15
0-7
0-3
12" Min wide notch cut into
benches at a 2:1 slope.
Filled with approved filter rock*
FIGURE 7
BACKDRAIN DETAIL (GEOFABRIC)
10”
MINIMUM
6” FILTER MATERIAL BEDDING
TYPICAL BENCHING
SEE DETAIL BELOW INCLINE TOWARD DRAIN
REMOVE UNSUITABLE MATERIAL
SURFACE OF FIRM
EARTH MATERIAL
4” DIAMETER MINIMUM APPROVED
PERFORATED PIPE**
(PERFORATIONS DOWN)
COMPACTED FILL
DETAIL
** APPROVED PIPE TYPE
Schedule 40 polyvinyl chloride
(P.V.C.) or approved equal.
Min. crush strength 1000 PSI.
Pipe diameter to meet hte following
criteria. Subject to field review based
on actual geotechnical conditions
encountered during grading.
Length of Run Pipe Diameter
Upper 500’ 4”
Next 1000’ 6”
>1500’ 8”
* Filter rock to meet following
specifications or approved equal.
Sieve
1"
3/4"
3/8"
No.4
No.30
No.50
No.200
% Passing
100
90-100
40-100
25-40
5-15
0-7
0-3
9 FT³ MINIMUM PER LINEAR FOOT
OF APPROVED FILTER ROCK*
FIGURE 8
NOT TO SCALE
TYPICAL CANYON SUBDRAIN DETAIL
...... :l-
······:{: .
....... ::l,. ...
24”
MINIMUM24”
MINIMUM
6” MINIMUM OVERLAP
SUPAC 8-P FABRIC
OR APPROVED EQUAL
60º TO 90º
TYPICAL BENCHING
SEE DETAIL BELOW INCLINE TOWARD DRAIN
REMOVE UNSUITABLE MATERIAL
SURFACE OF FIRM
EARTH MATERIAL
SUPAC 5-P FABRIC OR
APPROVED EQUAL
COMPACTED FILL
TRENCH DETAIL
OPTIONAL V-DITCH DETAIL
* Drainage material to meet following
specifications or approved equal.
Sieve
1 ½"
1"
3/4"
3/8”
No.200
% Passing
88-100
5-40
0-17
0-7
0-3
9 FT³ MINIMUM PER LINEAL FOOT
OF APPROVED FILTER ROCK*
9 FT³ MINIMUM PER LINEAL FOOT
OF APPROVED FILTER ROCK*
ADD MINIMUM 4” DIAMETER
APPROVED PERFORATED
PIPE WHEN GRADIENT IS
LESS THAN 2%
APPROVED PIPE TO BE SCHEDULE
40 POLY-VINYL-CHLORIDE (P.V.C.)
OR APPROVED EQUAL. MINIMUM
CRUSH STRENGTH 1000 psi.
FIGURE 9
NOT TO SCALE
GEOFABRIC SUBDRAIN
2’5%
1
1
UNSUIT
A
B
L
E
E
A
R
T
H
M
A
T
E
R
I
A
L
MINIMUM
DOWNSLOPE
KEY DEPTH
PROVIDE BACKDRAIN AS REQUIRED
PER RECOMMENDATIONS OF SOILS
ENGINEER DURING GRADING
WHERE NATURAL SLOPE GRADIENT IS 5:1 OR LESS,
BENCHING IS NOT NECESSARY. HOWEVER, FILL IS
NOT TO BE PLACED ON COMPRESSIBLE OR UNSUIT-
ABLE MATERIAL.
FINAL NATURAL SLOPE
TYPICAL
BENCH
HEIGHTS
LIMITS OF FINAL
EXCAVATION
TOE OF SLOPE SHOWN
ON GRADING PLAN
FILL
COMPETENT EARTH
MATERIAL
15’ MINIMUM BASE KEY WIDTH
10’ TYPICAL BENCH
WIDTH VARIES
4’
FIGURE 10
NOT TO SCALE
FILL SLOPE ABOVE NATURAL GROUND DETAIL
------
4’ TYPICAL
TOPSOIL
,
C
O
L
L
U
V
I
U
M
&
C
R
E
E
P
-
R
E
M
O
V
E
NOTE:
CUT SLOPE PORTION SHALL BE MADE
PRIOR TO PLACEMENT OF FILL
NATURAL TOPOGRAPHY
CUT/FILL CONTACT
SHOWN ON GRADING
PLAN
CUT/FILL CONTACT
SHOWN ON “AS-BUILT”
REMOVE ALL TOPSOIL, COLLUVIUM
AND CREEP MATERIAL FROM TRANSITION
FILL
BEDROCK OR APPROVED
FOUNDATION MATERIAL
CUT SLOPE*
16’ MINIMUM
10’ TYPICAL
FIGURE 11
NOT TO SCALE
FILL SLOPE ABOVE CUT SLOPE DETAIL
-------------------------------------
---------------------
-------------------------~---~
---------____ I r ..... :{:.
:~_ ................... ..
OVEREXCAVATE AND
REGRADE
TOPSOIL, C
O
LLUVIUM &
WEATHERE
D
B
E
D
R
O
C
K
UNWEATHERED BEDROCK
3’
5’5’
CUT LOT
OVEREXCAVATE AND
REGRADE
TOPSO
I
L
,
C
O
L
L
U
V
I
U
M
&
WEATH
E
R
E
D
B
E
D
R
OCK
UNWEATHERED BEDROCK
COMPACTED FILL
ORIGINA
L
GROUND
ORIGINAL
GROUND
3’
5’
CUT/FILL LOT (TRANSITION)
FIGURE 12
NOT TO SCALE
TRANSITION LOT DETAIL
---------------
---------------------------------
----------------------------------
FINISHED GRADE
CLEAR AREA FOR
FOUNDATION, UTILITIES,
AND SWIMMING POOLS
5’ OR BELOW DEPTH OF
DEEPEST UTILITY TRENCH
(WICHEVER GREATER)
HORIZONTALLY PLACED
COMPACTION FILL
SLOPE FACE
STREET
GRANULAR SOIL
FLOODED TO
FILL VOIDS
WINDROW
15’
15’
4’
10’
BUILDING
TYPICAL WINDROW DETAIL
(EDGE VIEW)
(PROFILE VIEW)
FIGURE 13
NOT TO SCALE
ROCK DISPOSAL DETAIL
l
0 0 0 0 ...... :1:.
0
O ............. :}
o····+-
~
0
q_ ··············-;-j_':. ---------··; 0
0 0 -------.. :,.:. •• -----------:-;: ______ _ \