HomeMy WebLinkAboutSDP 2022-0003; FPC RESIDENTIAL - SB 330; PRELIMINARY GEOTECHNICAL INVESTIGATION AND INFILTRATION STUDY; 2022-03-16 ADVANCED GEOTECHNICAL SOLUTIONS, INC.
485 Corporate Drive, Suite B
Escondido, California 92029
Telephone: (619) 867-0487 Fax: (714) 409-3287
ORANGE AND L.A. COUNTIES INLAND EMPIRE SAN DIEGO AND IMPERIAL COUNTIES
(714) 786-5661 (619) 867-0487 (619) 867-0487
H.G. Fenton Company March 16, 2022
7577 Mission Valley Road P/W 2107-12
San Diego, California 92108 Report No. 2107-12-B-4
Attention: Ryley Webb
Subject: Preliminary Geotechnical Investigation and Infiltration Study, Proposed
Multi-Family Residential Development, 7200-7294 Ponto Drive, Carlsbad, California
References: Appendix A
Gentlepersons:
Pursuant to your request, Advanced Geotechnical Solutions, Inc. (AGS) has prepared this preliminary
geotechnical investigation and infiltration study for the proposed multi-family residential development
located on 7200-7294 Ponto Drive in the City of Carlsbad, California. In this report, AGS presents the
results of our geotechnical investigation, and we discuss geologic/geotechnical issues associated with
grading and development of the proposed project. AGS appreciates the opportunity to provide you with geotechnical consulting services on this project. If
you have questions concerning this report, please do not hesitate to contact the undersigned at (619) 867-
0487.
Respectfully Submitted,
Advanced Geotechnical Solutions, Inc.
Prepared by:
__________________________
ANDRES BERNAL
RCE 62366/GE 2715, Reg. Exp. 9-30-23
Reviewed by:
___________________________ _____________________________
JOHN J. DONOVAN PAUL J. DERISI
RCE 65051/GE 2790, Reg. Exp. 6-30-23 CEG 2536, Reg. Exp. 5-31-23
Distribution: (1) Addressee (electronic copy)
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
TABLE OF CONTENTS
Page
1.0 INTRODUCTION .............................................................................................................. 1
1.1. Scope of Study ................................................................................................................ 1
1.2. Geotechnical Study Limitations ...................................................................................... 2
2.0 SITE LOCATION AND PROPOSED DEVELOPMENT ................................................. 2
3.0 SITE INVESTIGATION AND LABORATORY TESTING ............................................. 2
4.0 ENGINEERING GEOLOGY ............................................................................................. 3
4.1. Regional Geologic and Geomorphic Setting .................................................................. 3
4.2. Site Geology.................................................................................................................... 3
4.2.1. Artificial Fill - Undocumented (Map Symbol afu) ................................................. 3
4.2.2. Alluvium (Map Symbol Qal) .................................................................................. 3
4.2.3. Quaternary Old Paralic Deposits (Map Symbol Qop) ............................................ 4
4.3. Groundwater ................................................................................................................... 4
4.4. Non-Seismic Hazards...................................................................................................... 4
4.4.1. Mass Wasting .......................................................................................................... 4
4.4.2. Flooding and Tsunami ............................................................................................ 4
4.4.3. Subsidence and Ground Fissuring .......................................................................... 4
4.5. Seismic Hazards .............................................................................................................. 4
4.5.1. Surface Fault Rupture ............................................................................................. 4
4.5.2. Seismicity ................................................................................................................ 5
4.5.3. Seismic Design Parameters ..................................................................................... 5
4.5.4. Liquefaction ............................................................................................................ 5
4.5.5. Dynamic Settlement ................................................................................................ 6
4.5.6. Lateral Spreading .................................................................................................... 6
4.5.7. Landsliding ............................................................................................................. 6
4.5.8. Earthquake Induced Flooding ................................................................................. 6
5.0 GEOTECHNICAL ENGINEERING .................................................................................. 6
5.1. Excavation Characteristics .............................................................................................. 6
5.2. Compressibility ............................................................................................................... 7
5.3. Expansion Potential ........................................................................................................ 7
5.4. Earthwork Adjustments .................................................................................................. 7
5.5. Shear Strength ................................................................................................................. 7
5.6. Analytical Methods ......................................................................................................... 8
5.6.1. Bearing Capacity ..................................................................................................... 8
5.6.2. Lateral Earth Pressures ........................................................................................... 8
5.7. Pavement Support Characteristics .................................................................................. 8
6.0 CONCLUSIONS AND RECOMMENDATIONS ............................................................. 8
6.1. Earthwork ........................................................................................................................ 8
6.1.1. Site Preparation ....................................................................................................... 8
6.1.2. Removals and Overexcavation ............................................................................... 9
6.1.3. Cut-Fill Transitions ................................................................................................. 9
6.1.4. Materials for Fill ..................................................................................................... 9
6.1.5. Import Soils ............................................................................................................. 9
6.1.6. Compacted Fill ...................................................................................................... 10
6.1.7. Mixing and Moisture Control ............................................................................... 10
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6.1.8. Utility Trench Backfill .......................................................................................... 10
6.1.9. Flatwork Subgrade Preparation ............................................................................. 10
6.2. Excavations and Shoring ............................................................................................... 10
6.3. Foundation Design Recommendations ......................................................................... 11
6.4. Conventional Foundations ............................................................................................ 11
6.5. Post-Tensioned Foundations ......................................................................................... 12
6.6. Additional Recommendations ....................................................................................... 13
6.6.1. Footing Excavations .............................................................................................. 13
6.6.2. Isolated Footings ................................................................................................... 14
6.6.3. Moisture and Vapor Barrier .................................................................................. 14
6.6.4. Lateral Earth Pressures ......................................................................................... 14
6.6.5. Seismic Earth Pressure .......................................................................................... 14
6.6.6. Retaining Wall Backfill and Drainage .................................................................. 15
6.7. Exterior Flatwork .......................................................................................................... 16
6.8. Preliminary Pavement Design ....................................................................................... 16
6.9. Site Drainage ................................................................................................................. 16
6.10. Corrosion....................................................................................................................... 17
6.11. Concrete Mix Design .................................................................................................... 17
6.12. Buried Metallic Materials ............................................................................................. 17
7.0 FUTURE STUDY NEEDS ............................................................................................... 17
7.1. Plan Review .................................................................................................................. 17
7.2. Observation during Construction .................................................................................. 17
8.0 CLOSURE ........................................................................................................................ 18
ATTACHMENTS:
Figure 1 - Site Location Map
Figure 2 - Regional Geologic Map
Figure 3 - Retaining Wall Backfill and Drainage
Plate 1 - Exploration Location Plan
Appendix A - References
Appendix B - Subsurface Exploration
Appendix C - Laboratory Test Results
Appendix D - Preliminary Infiltration Feasibility Study
Appendix E - Earthwork Specifications
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
PRELIMINARY GEOTECHNICAL INVESTIGATION AND INFILTRATION STUDY
MULTI-FAMILY RESIDENTIAL DEVELOPMENT
7200-7294 PONTO DRIVE, CARLSBAD, CALIFORNIA
1.0 INTRODUCTION
Advanced Geotechnical Solutions, Inc., (AGS) has prepared this report which presents the results of our
geotechnical investigation onsite and provides specific recommendations for the design and construction
of the proposed multi-family residential development in the City of Carlsbad, California.
1.1. Scope of Study
The scope of this study included the following tasks:
Review of pertinent published and unpublished geologic and geotechnical literature, maps, and
aerial photographs (Appendix A, References).
Geotechnical site reconnaissance to observe site surface conditions and select exploratory
locations.
Subsurface exploration consisting of hollow-stem auger borings, percolation test borings and
trench excavations (Appendix B).
Geotechnical laboratory testing on selected soil samples (Appendix C).
Perform borehole percolation tests to evaluate the feasibility of storm water infiltration in
accordance with the current City of Carlsbad - BMP Design Manual (Appendix D).
Compile and analyze data collected from our site reconnaissance, subsurface evaluation, and
laboratory testing. Specifically, our analyses included the following:
o Evaluation of general subsurface conditions and description of types, distribution, and
engineering characteristics of subsurface materials;
o Evaluation of geologic hazards and engineering seismology, including evaluation of fault
rupture hazard, seismic shaking hazard, liquefaction and seismic settlement potential;
o Evaluation of seismic design parameters in accordance with 2019 California Building Code;
o Evaluation of groundwater conditions at the site;
o Evaluation of expansion potential of on-site soils;
o Development of general recommendations for earthwork, including requirements for
placement of compacted fill;
o Evaluation of foundation design parameters including allowable bearing capacity for
shallow foundations, estimated settlement, and lateral resistance;
o Recommendations for temporary excavations;
o Recommendations for concrete slab-on-grade support and concrete flatwork;
o Recommendations for flexible and rigid pavement design; and,
o Evaluation of the potential for on-site materials to corrode buried concrete and metals.
Compile this report to present the work performed, data acquired and our conclusions and
geotechnical recommendations for the design and construction of the proposed improvements.
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1.2. Geotechnical Study Limitations
The conclusions and recommendations in this report are professional opinions based on the data
developed during this investigation. The conclusions presented herein are based upon our
assumptions regarding the proposed residential development. Once detailed project plans become
available, further review and recommendations by AGS may be necessary.
The materials immediately adjacent to or beneath those observed may have different characteristics
than those observed. No representations are made as the quality or extent of material not observed.
Any evaluation regarding the presence or absence of hazardous material is beyond the scope of this
firm’s services.
2.0 SITE LOCATION AND PROPOSED DEVELOPMENT
The approximately 4.64 acre site is located north of Ponto Avenue in Carlsbad, California as shown in
Figure 1, Site Location Map. The site encompasses three parcels which are located northeast of the
intersection of Ponto Drive and Ponto Road: APN 214-160-25-00 (1.52 acres), 214-171-11-00 (2.24 acres),
and 214-160-28 (0.92 acres). The parcel north of Ponto Avenue and east of Ponto Drive is currently
occupied by a self-storage facility, which was constructed between 1967 and 1978. The site to the north has
been periodically used as a storage/junk yard and more recently as a contractor lay-down yard, and no
permanent structures are present on the property. The site just to the east is mostly undeveloped aside from
two vacant structures which were constructed between 1967 and 1978.
The site slopes and drains to the south. Based on our review of historical aerial imagery circa 1947, a north-
south trending drainage was located on the self-storage site and contractor site prior to development. This
was filled in and moved by 1953. The channel continued to the south roughly along the current alignment
of Ponto Drive and was filled in and/or moved by 1964. As shown on the Base Map prepared by Hunsaker
and Associates San Diego, site elevations range between 48 feet above mean sea level (msl) on the
southeastern corner to 38 ft. msl on the southwestern corner. A high-pressure gas line with a 10-foot
easement crosses the site from north to south.
According to the Design Study plan prepared by Hunsaker & Associates San Diego, Inc. (2022), it is our
understanding that the project consists of twenty-three two- and three-story multi-family buildings with
parking in the first level, and associated driveways, parking and open space areas. Additional improvements
include sound walls, retaining walls and utility installations. Cuts and fills up to 5 feet in depth are
anticipated.
3.0 SITE INVESTIGATION AND LABORATORY TESTING
On September 20, 2021, AGS performed subsurface exploration at the site consisting of seven hollow-stem
auger soil borings (B-1 through B-7) which were logged and sampled by a representative of this firm. The
borings were advanced with a truck-mounted drill rig to depths ranging between 2 feet and 26.5 feet below
existing ground surface (bgs). On January 31, 2022, AGS observed the excavation with a backhoe of ten
test pits (TP-1 through TP-10) onsite to depths ranging between 3.5 feet and 13.5 feet bgs. The approximate
locations of the exploratory borings and test pit excavations are presented on Plate 1, Exploration Location
Plan. Boring and test pit logs are presented in Appendix B.
FIGURE
1
DATE:
3/22
SITE LOCATION MAP
PROJECT NO.:
2107-12
NOTE: ALL DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE.SOURCE: USGS, US TOPO MAPS, 2021.
PROPOSED MULTI-FAMILY RESIDENTIAL DEVELOPMENT
7294 - 7590 PONTO DRIVE
CARLSBAD, CALIFORNIA
N
SITE
SCALE 1”= 1,000’
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
Representative bulk and “undisturbed” ring samples were transported to our laboratory for testing. Testing
included in-situ moisture content and density, consolidation characteristics, undisturbed and remolded shear
strength, maximum density and optimum moisture content, expansion potential, and chemical/corrosivity
analysis. Laboratory test results are presented in Appendix C.
In addition, five (5) borehole percolation tests (P-1 through P-5) with depths ranging between 5 and 5.5 feet
bgs were performed to evaluate the feasibility of storm water infiltration and provide preliminary design
infiltration rates in general conformance with the City of Carlsbad BMP Design Manual guidelines. The
results of the infiltration study are presented in Appendix D. Additional infiltration testing may be needed
once detailed stormwater management plans are developed for the site.
4.0 ENGINEERING GEOLOGY
4.1. Regional Geologic and Geomorphic Setting
The subject site is situated within the Peninsular Ranges Geomorphic Province. The Peninsular
Ranges province occupies the southwestern portion of California and extends southward to the
southern tip of Baja California. In general, the province consists of young, steeply sloped, northwest
trending mountain ranges underlain by metamorphosed Late Jurassic to Early Cretaceous-aged
extrusive volcanic rock and Cretaceous-aged igneous plutonic rock of the Peninsular Ranges
Batholith. The westernmost portion of the province is predominantly underlain by younger marine
and non-marine sedimentary rocks. The Peninsular Ranges’ dominant structural feature is
northwest-southeast trending crustal blocks bounded by active faults of the San Andreas transform
system.
4.2. Site Geology
Current published regional geologic maps indicate the site is underlain by Quaternary-age Old
Paralic Deposits (Kennedy, M.P., and Tan, S.S., 2007) as shown in Figure 2, Regional Geologic
Map. The following is a brief description of the geologic units encountered during our geotechnical
investigation.
4.2.1. Artificial Fill - Undocumented (Map Symbol afu)
Artificial fill soils mantle the majority of the site. These soils consist of reddish brown,
yellowish brown and grayish brown, dry to moist, sand, silty sand to clayey sand in a loose
to medium dense condition. Construction debris consisting of large concrete clasts, asphalt
fragments and reinforcement steel bars were encountered in borings B-5 through B-7, and
test pits TP-4 through TP-6, TP-8 and TP-10. The lateral extent of the construction debris
fill was not readily evident based on our observations. Artificial fill thickness is estimated
to generally range from approximately 2.5 to 6 feet bgs with localized deeper areas. Minor
amounts of organic content and roots were also observed within artificial fill in several
locations.
4.2.2. Alluvium (Map Symbol Qal)
Alluvial deposits were encountered in the eastern portion of the site and consist of brown
to red brown, dry to moist, loose to medium dense, fine- to coarse-grained silty sand and
FIGURE
2
DATE
3/22
PROJECT NO.
2107-12
REGIONAL GEOLOGIC MAP
NOTE: ALL DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE.
PROPOSED MULTI-FAMILY RESIDENTIAL DEVELOPMENT
7294 - 7590 PONTO DRIVE
CARLSBAD, CALIFORNIA
LEGEND
YOUNG ALLUVIAL FLOOD PLAIN DEPOSITS
PARALIC ESTUARINE DEPOSITS
OLD PARALIC DEPOSITS, UNITS 6-7
OLD PARALIC DEPOSITS, UNITS 2-4
N
Tsa
SOURCE: GEOLOGIC MAP OF THE OCEANSIDE 30’ X 60’ QUADRANGLE, 2007.
SITE
Qop2-4
Qls
Kt
Qvop12
NTS
Qop6-7
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
clayey sand with a pebble lag deposit at the bottom in test pits TP-2 and TP-4. Alluvial
deposits were observed to extend to depths ranging between 1.5 and 6 feet bgs.
4.2.3. Quaternary Old Paralic Deposits (Map Symbol Qop)
Quaternary-age Old Paralic Deposits (Units 6 and 7) were encountered at the surface in
boring B-1 and at shallow depths elsewhere. These soils generally consist of light yellow,
grayish-brown, reddish brown to yellowish brown, with iron oxide staining, moist to
saturated, medium dense to very dense, silty to clayey, fine- to coarse-grained sand. A layer
of light olive, highly expansive clay was encountered at an approximate depth of 4 feet in
the northern portion of the site. Except for the upper weathered portion, this unit is suitable
for support of fills and anticipated structural loads.
4.3. Groundwater
Groundwater was encountered in boring B-2 at 20.5 ft. depth which corresponds to approximate
El. 19 ft. msl. Localized perched groundwater may develop at a later date, most likely at or near
fill/bedrock contacts, due to fluctuations in precipitation, irrigation practices, or factors not evident
at the time of our field explorations.
4.4. Non-Seismic Hazards
4.4.1. Mass Wasting
No evidence of mass wasting was observed onsite nor was any noted on the reviewed maps.
4.4.2. Flooding and Tsunami
According to available FEMA maps, the site is not within an identified flood hazard zone.
4.4.3. Subsidence and Ground Fissuring
Due to the presence of the dense underlying formational materials, and the lack of deep
unconsolidated soils, the potential for subsidence and ground fissuring due to settlement is
unlikely.
4.5. Seismic Hazards
The project is located in the tectonically active southern California and will likely experience some
effects from future earthquakes. The type or severity of seismic hazards affecting the site is chiefly
dependent upon the distance to the causative faults, the intensity and duration of the seismic events,
and the onsite soil characteristics. The seismic hazard may be primary, such as surface rupture
and/or ground shaking, or secondary, such as liquefaction or landsliding. The following is a site-
specific discussion of earthquake-induced/seismic hazards and proposed mitigations, if necessary,
to reduce the hazard to an acceptable level of risk.
4.5.1. Surface Fault Rupture
Surface rupture is a break in the ground surface during, or as a consequence of, seismic
activity. Fault rupture occurs most often along pre-existing fault traces. Based on our
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
observation of the site and review of available geologic maps, there is no known faulting
at the subject site. The nearest active fault is the Rose Canyon/Newport-Inglewood Fault
system which is approximately 3.6 miles west of the site. Accordingly, the potential for
fault surface rupture within the project is very low.
4.5.2. Seismicity
As noted, the site is within the tectonically active southern California area, and the potential
exists for strong ground motion that may affect future improvements. At this point in time,
non-critical structures (commercial, residential, and industrial) are usually designed
according to the 2019 California Building Code requirements and those of the controlling
local agency.
4.5.3. Seismic Design Parameters
After implementation of the grading recommendations provided in this report, the site may
be classified as Seismic Site Class D consisting of a stiff soil profile with average SPT N
blowcount between 15 and 50 blows per foot. Table 4.5.3 presents seismic design
parameters in accordance with 2019 California Building Code (CBC) and mapped spectral
acceleration parameters (United States Geological Survey, 2022) utilizing site coordinates
of Latitude 33.096°N and Longitude 117.3148°W.
TABLE 4.5.3
2019 CBC SEISMIC DESIGN PARAMETERS
Seismic Site Class D
Mapped Spectral Acceleration Parameter at Period of 0.2-Second, Ss 1.154
Mapped Spectral Acceleration Parameter at Period 1-Second, S1 0.412
Site Coefficient, Fa 1.039
Site Coefficient, Fv N/A3
Adjusted MCER1 Spectral Response Acceleration Parameter at Short Period, SMS 1.198
1-Second Period Adjusted MCER1 Spectral Response Acceleration Parameter, SM1 N/A3
Short Period Design Spectral Response Acceleration Parameter, SDS 0.799
1-Second Period Design Spectral Response Acceleration Parameter, SD1 N/A3
Peak Ground Acceleration, PGAM2 0.566
Seismic Design Category N/A3
Notes:
1 Risk-Targeted Maximum Considered Earthquake
2 Peak Ground Acceleration adjusted for site effects
3 Requires a Site Specific Ground Motion Hazard Analysis per ASCE 7-16 Section 11.4.8 unless, per Exception 2,
the value of seismic response coefficient CS is determined by Equation 12.8-2 for values of T 1.5TS and taken as
equal to 1.5 times the values computed with either Equation 12.8-3 for TL ≥ T >1.5Ts or Equation 12.8-4 for T > TL.
4.5.4. Liquefaction
Liquefaction is the phenomenon where seismic agitation of loose, saturated sands and silty
sands can result in a buildup of pore pressures that, if sufficient to overcome overburden
stresses, can produce a temporary quick condition. Localized, loose lenses/layers of sandy
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soils may be subject to liquefaction when a large, prolonged, seismic event affects the site.
As the excess pore water pressure dissipates, the liquefied zones/lenses can consolidate
causing settlement. The subject site is not in a liquefaction susceptibility zone. Due to the
dense nature of the underlying old paralic deposits the potential for seismically induced
liquefaction is anticipated to be “very low”.
4.5.5. Dynamic Settlement
Dynamic settlement may occur in response to an earthquake event in loose, unsaturated
sandy earth materials. Based on the very dense consistency of the native soils, the potential
for dynamic settlement at the site is considered “very low”.
4.5.6. Lateral Spreading
Liquefaction-induced lateral spreading is defined as the finite, lateral displacement of
gently sloping ground as a result of pore pressure build-up or liquefaction in a shallow
underlying deposit during an earthquake. Since the potential for liquefaction is low, the
potential for lateral spreading is also low.
4.5.7. Landsliding
Landslides are deep-seated ground failures in which a crown-shaped section of a slope
separates and slides downhill. The project site is not mapped within a landslide susceptible
area. The fill slope for the railroad is not expected to be prone to seismically induced
landsliding. Given the relatively flat gradients across the site, landsliding, mass wasting,
and/or surficial instability onsite is considered to be remote.
4.5.8. Earthquake Induced Flooding
Earthquake induced flooding can be caused by tsunamis, dam failures, or seiches. A seiche
is a free or standing-wave oscillation on the surface of water in an enclosed or semi-
enclosed basin. Due to the lack of a freestanding body of water nearby, the potential for a
seiche impacting the site is considered to be non-existent. Considering the lack of dams
located above the site, earthquake induced flooding caused by a dam failure is considered
to be nonexistent. Our review of the 2009 Tsunami Inundation Map for Emergency
Planning prepared by CalEMA, indicates that the site is not within the tsunami inundation
zone.
5.0 GEOTECHNICAL ENGINEERING
Presented herein is a general discussion of the geotechnical properties of the various soil types and earth
materials observed by AGS based on the current design study. The following is a summary of our opinions
based upon the available data. Additional recommendations may be provided after precise grading and
foundation plans are available for review.
5.1. Excavation Characteristics
Based on our previous experience with similar projects in the vicinity of the site, it is our opinion
that the majority of the earth material onsite can be readily excavated with conventional grading
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equipment. Complete removal of construction debris including rebar, asphalt and concrete
fragments is recommended. Special handling may be necessary for removal of large concrete clasts.
5.2. Compressibility
The site is underlain by shallow artificial fill and alluvium over Old Paralic Deposits. The artificial
fill, alluvium and upper weathered portion of Old Paralic Deposits, if encountered, are expected to
be compressible. Mitigation would include removing and replacing the upper compressible soils
with compacted fill.
5.3. Expansion Potential
Expansive soils are characterized by their ability to undergo significant volume changes (shrink or
swell) due to variations in moisture content. Changes in soil moisture content can result from
precipitation, landscape irrigation, utility leakage, roof drainage, perched groundwater, drought, or
other factors and may result in unacceptable settlement or heave of structures or concrete slabs
supported on grade. Based on our laboratory testing, it is anticipated that the expansion potential
of the onsite materials will vary “Very Low” to “High” when classified in accordance with ASTM
D 4829. Mitigation measures for expansive soils are provided in the recommendations section of
this report.
5.4. Earthwork Adjustments
The following average earthwork adjustment factors are presented for use in evaluating earthwork
quantities. These numbers are considered approximate and should be refined during grading when
actual conditions are better defined. Contingencies should be made to adjust the earthwork balance
during grading if these numbers are adjusted.
TABLE 5.4
EARTHWORK ADJUSTMENTS
Geologic Unit Approximate Range
Existing Fill / Alluvium / Weathered Old Paralic Deposits 5 to 15 percent shrinkage
Competent Old Paralic Deposits 0 to 5 percent bulk
5.5. Shear Strength
Shear strength testing was conducted on a remolded sample of site soil. The results are presented
in Appendix C. The shear strength parameters used by AGS for design are presented below.
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TABLE 5.5
SHEAR STRENGTH PARAMETERS USED FOR DESIGN (ULTIMATE)
Material Cohesion
(psf)
Friction Angle
(degrees)
Moist Density
(pcf)
Compacted Fill and Competent
Old Paralic Deposits 150 32 130
5.6. Analytical Methods
5.6.1. Bearing Capacity
Ultimate bearing capacity and shoring design values were obtained using the graphs and
formulas presented in NAVFAC DM-7.1. Allowable bearing was determined by applying
a factor of safety of at least three to the ultimate bearing capacity.
5.6.2. Lateral Earth Pressures
Static lateral earth pressures were calculated using Rankine methods for active and passive
cases. If it is desired to use Coulomb forces, a separate analysis specific to the application
can be conducted.
5.7. Pavement Support Characteristics
It is anticipated that the onsite soils will have moderate support characteristics. Depending upon
the final distribution of site soils, pavement support characteristics could vary. If structural
pavements are to be constructed (concrete or asphaltic concrete), an R-value of 25 can be utilized
for the preliminary design of pavements. Final design should be based upon representative
sampling of the as-graded soils.
6.0 CONCLUSIONS AND RECOMMENDATIONS
Based on the information provided herein, construction of the proposed improvements is considered
feasible from a geotechnical standpoint provided the conclusions and recommendations presented herein
are incorporated into the design and construction of the project.
6.1. Earthwork
Earthwork should be accomplished under the observation and testing of the project soils engineer
and engineering geologist or their authorized representative in accordance with our
recommendations, the project specifications, the requirements of the applicable governing
agencies.
6.1.1. Site Preparation
Site preparation should begin with the removal of utility lines, asphalt, concrete, and other
deleterious debris from areas to be graded. Clearing and grubbing should minimally extend
to the limits of proposed excavation and fill areas. The debris and unsuitable material
generated during clearing and grubbing should be removed from areas to be graded and
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disposed of at a legal dumpsite away from the project area. Abandoned utilities should be
removed and/or backfilled with slurry in accordance with local regulations.
6.1.2. Removals and Overexcavation
Grading should be accomplished under the observation and testing of the project
geotechnical engineer and engineering geologist or their authorized representative in
accordance with the recommendations contained herein, the City of Carlsbad grading
ordinance and AGS’s Earthwork Specifications (Appendix E). Topsoil, alluvium, artificial
fill and the highly weathered portions of old paralic deposits should be removed where
exposed at design grade or in areas planned to receive compacted fill intended to support
settlement-sensitive structures such as buildings, roads and underground improvements.
The resulting undercuts should be replaced with engineered fill. Removals depths ranging
between 2 and 6 feet are anticipated. It should be noted that local variations can be expected
requiring an increase in the depth of removal for unsuitable and weathered deposits.
It is possible that a highly expansive clay layer within Old Paralic deposits may be exposed
at or near pad grade. Should such layers occur in the near-surface, undercutting to depths
of 5 to 10 feet and replacement with compacted fill may be warranted.
6.1.3. Cut-Fill Transitions
The proposed structures should be supported entirely on compacted fill or competent old
paralic deposits. Overexcavation may be needed if the planned unsuitable soils removals
or design grades create a transition within the building footprint between native deposits
and compacted fill. If this occurs the building area should be overexcavated to provide a
minimum of 3 feet of compacted fill below pad grade or 1 foot below footings, whichever
is deeper. The limit of this overexcavation should extend 5 feet outside the building limits,
where possible. As an alternative, footing excavations can be deepened so that they extend
into competent old paralic deposits.
6.1.4. Materials for Fill
Onsite soils with an organic content of less than approximately 3 percent by volume (or 1
percent by weight) are suitable for use as fill. In general, fill material should not contain
rocks or lumps over approximately 8 inches in largest dimension. Soils classified as silts
or clays should not be used for backfill in the pipe zone. Larger chunks, if generated during
excavation, may be broken into acceptably sized pieces or disposed of offsite.
6.1.5. Import Soils
Import soils, if required, should consist of clean, structural quality, compactable materials
and should be free of trash, debris or other objectionable materials. Import soils should be
tested and approved by the Geotechnical Consultant prior to importing. At least three
working days should be allowed in order for the geotechnical consultant to sample and test
the potential import material.
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6.1.6. Compacted Fill
Prior to placement of compacted fill, the contractor should request an evaluation of the
exposed ground surface by AGS. Unless otherwise recommended, the exposed ground sur-
face should then be scarified to a depth of approximately 8 inches and watered or dried, as
needed, to achieve moisture contents slightly above the optimum moisture content. The
scarified materials should then be compacted 90 percent of the maximum dry density as
determined by ASTM D1557. Fill should be placed in thin (6 to 8-inch) lifts, moisture
conditioned to optimum moisture or slightly above, and compacted to a minimum of 90
percent relative compaction until the desired grade is achieved.
6.1.7. Mixing and Moisture Control
In order to prevent layering of different soil types and/or different moisture contents,
mixing and moisture control of materials will be necessary. The preparation of the earth
materials through mixing and moisture control should be accomplished prior to and as part
of the compaction of each fill lift.
6.1.8. Utility Trench Backfill
Utility trench backfill should be compacted to at least 90 percent of maximum dry density
as determined by ASTM D 1557. Onsite soils will not be suitable for use as bedding
material but will be suitable for use in backfill. No surcharge loads should be imposed
above excavations. This includes spoil piles, lumber, concrete trucks or other construction
materials and equipment.
Drainage above excavations should be directed away from the banks. Care should be taken
to avoid saturation of the soils. Compaction should be accomplished by mechanical means.
Jetting of native soils will not be acceptable.
6.1.9. Flatwork Subgrade Preparation
The upper one foot of subgrade soil below exterior slabs, sidewalks, driveways, patios, etc.
should be compacted to a minimum of 90 percent of the maximum dry density as
determined by ASTM D1557. The subgrade below exterior slabs, sidewalks, driveways,
patios, etc. should be moisture conditioned to 110 percent of optimum moisture content
prior to concrete placement.
6.2. Excavations and Shoring
Excavations and utility trenches should be laid back in accordance with applicable Cal-OSHA
standards. Based on our observations, onsite soils may be classified as Cal-OSHA soil type “C”.
Any temporary excavation greater than 5 feet in height should be laid back with a 1.5:1
(horizontal:vertical) gradient. These excavations should not become saturated or allowed to dry
out. Although not anticipated, temporary excavations that encounter seepage may need to be
stabilized by placing sandbags or gravel along the base of the seepage zone and should be evaluated
on a case-by-case basis. As an alternative to laying back the side walls, the excavations may be
shored or braced.
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Excavated areas should be backfilled as soon as practicable. The stability of the excavations
decreases over time as the soil dries and weathers. On-site safety of personnel is the responsibility
of the contractor.
6.3. Foundation Design Recommendations
Detailed foundation plans are not currently available; however, it is our understanding that the
proposed two- and three-story residential structures will be supported by conventional or post-
tensioned shallow foundation systems. The following values may be used in preliminary foundation
design:
Allowable Bearing: 2000 psf.
Lateral Bearing: 250 psf per foot of embedment depth
to a maximum of 2000 lbs./sq.ft.
Sliding Coefficient: 0.35
Settlement: Total = 3/4 inch
Differential: 3/8 inch in 20 feet
Static settlement of the foundation system is expected to occur on initial application of loading. For
resisting lateral forces on footings, lateral bearing and sliding coefficient may be combined with a
maximum sliding resistance limited to ½ of dead load.
The above values may be increased as allowed by Code to resist transient loads such as wind or
seismic. Building code and structural design considerations may govern. Depth and reinforcement
requirements and should be evaluated by a qualified engineer.
6.4. Conventional Foundations
The design of foundation systems should be based on as-graded conditions as determined after
grading completion. For design of shallow foundations supported on competent Old Paralic
Deposits or compacted fill with expansion potential of “Low” to “Medium”, the recommendations
provided in Table 6.4 should be used.
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TABLE 6.4
CONVENTIONAL SLAB ON GRADE FOUNDATION DESIGN
Expansion Potential Very Low to Low (Cat. I) Medium (Cat. II)
Footing Depth Below Lowest Adjacent Finish Grade
Two-Story 12 inches 18 inches
Three-Story 12 inches 18 inches
Footing Width
Two-Story 15 inches 15 inches
Three-Story 18 inches 18 inches
Footing Reinforcement
Two- and Three-Story
No. 4 rebar, two (2) on top and two
(2) on bottom or No. 5 rebar one (1)
on top and one (1) on bottom
No. 4 rebar, two (2) on top and two
(2) on bottom or No. 5 rebar one (1)
on top and one (1) on bottom
Slab Thickness 5 inches (actual) 5 inches (actual)
Slab Reinforcement No. 3 rebar spaced 18 inches on
center, each way
No. 3 rebar spaced 15 inches on
center, each way
Slab Subgrade
Moisture
Minimum of optimum moisture
prior to placing concrete.
Minimum 120% of optimum moisture
24 hours prior to placing concrete.
Footing Embedment Next to Swales and Slopes
If exterior footings adjacent to drainage swales are to exist within five (5) feet horizontally of the swale, footings should
be embedded sufficiently to ensure embedment below the swale bottom. Footings adjacent to slopes should be
embedded such that a least seven (7) feet are provided horizontally from the edge of footing to the face of slope.
Garages
A grade beam reinforced continuously with the garage footings shall be constructed across the garage entrance, tying
together the ends of the perimeter footings and between individual spread footings. This grade beam should be
embedded at the same depth as the adjacent perimeter footings. A thickened slab, separated by a cold joint from the
garage beam, should be provided at the garage entrance. Minimum dimensions of the thickened edge shall be six (6)
inches deep. Footing depth, width and reinforcement should be the same as the structure. Slab thickness, reinforcement
and underslab treatment should be the same as the structure.
Isolated Spread Footings
Isolated spread footings should be embedded a minimum of 18 inches below lowest adjacent finish grade and should at
least 24 inches wide. A grade beam should also be constructed for interior and exterior spread footings and should be
tied into the structure in two orthogonal directions, footing dimensions and reinforcement should be similar to the
aforementioned continuous footing recommendations. Final depth, width and reinforcement should be determined by
the structural engineer
6.5. Post-Tensioned Foundations
Post-tensioned foundations may be designed using the values provided in Table 6.5. Design and
construction of post-tensioned foundations should be undertaken by firms experienced in the field.
It is the responsibility of the foundation design engineer to select the design methodology and
properly design the foundation system for the onsite soils conditions. The slab designer should
provide deflection potential to the project architect/structural engineer for incorporation into the
design of the structure.
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TABLE 6.5
POST-TENSIONED FOUNDATION DESIGN PARAMETERS
Soil
Category
Expansion
Index Lot No.
Edge Beam
Embedment
(inches)*
Edge Lift** Center Lift**
Em (ft.) Ym (in.) Em (ft.) Ym (in.)
I “Low” *** 12 5.4 0.54 9.0 -0.23
II “Medium” *** 18 4.6 0.90 9.0 -0.38
Moisture Barrier An approved moisture and vapor barrier should be placed below all slabs-on-
grade within living and moisture sensitive areas as discussed in Section 3.5
Slab Subgrade
Moisture
Soil Category I Minimum of 100 percent of optimum moisture to a depth of
12 inches prior to placing concrete
Soil Category II Minimum of 120 percent of optimum moisture to a depth of
12 inches prior to placing concrete
Footing
Embedment
*Depth of embedment should be measured below lowest adjacent finish grade.
Footings Adjacent to Swales and Slopes: If exterior footings adjacent to
drainage swales are to exist within 5 feet horizontally of the swale, the footing
should be embedded sufficiently to assure embedment below the swale bottom
is maintained. Footings adjacent to slopes should be embedded such that at least
5 feet is provided horizontally from edge of the footing to the face of the slope.
NOTES: ** The values of predicted lift are based on the procedures outlined in the Design of Post-Tensioned
Slabs-on-Ground, Third Edition and related addendums. No corrections for vertical barriers at the edge of
the slab or other corrections (e.g. horizontal barriers, tree roots, adjacent planters) are assumed. The values
assume Post-Equilibrium conditions exist (as defined by the Post Tensioning Institute), and these conditions
created during construction should be maintained throughout the life of the structure.
*** Final design parameters should be provided in a final grading report and should be based on as-graded
soil conditions.
Post-tensioned slabs should incorporate a perimeter-thickened edge to reduce the potential for
moisture infiltration, seasonal moisture fluctuation and associated differential movement around
the slab perimeter. The minimum recommended depth of the thickened edge is 12-inches for “low”
expansion and 18-inches for “medium” expansion.
The project foundation design engineer should use the Post-Tensioning Institute (PTI) foundation
design procedures as described in 2019 CBC, based upon appropriate soil design parameters
relating to edge moisture variation and differential swell provided by the geotechnical consultant
at the completion of rough grading operations. For preliminary design and budgeting purposes,
Category I design parameters may be assumed. Upon completion of rough grading, finish grade
samples should be collected and tested to develop final foundation design recommendations for
individual lots.
6.6. Additional Recommendations
6.6.1. Footing Excavations
Footing excavations should be observed by the geotechnical consultant. Footings should
be excavated into either compacted fill or competent native materials. The excavations
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should be free of all loose and sloughed materials, be neatly trimmed, and moisture
conditioned at the time of concrete placement. Footing excavations should not be allowed
to dry back and should be kept moist until concrete is poured.
6.6.2. Isolated Footings
Isolated footings outside the structure footprint should be tied with grade beams to the
structure in two orthogonal directions.
6.6.3. Moisture and Vapor Barrier
A moisture and vapor retarding system should be placed below the slabs-on-grade in
portions of the structure considered to be moisture sensitive. The concrete slab
underlayment should consist of a 15-mil vapor retarder, Stego-wrap or equivalent, with all
laps sealed per 2019 CBC requirements and the manufacturer’s recommendation. The
vapor retarder should comply with the ASTM E 1745 - Class A criteria and be installed in
accordance with ACI 302.1R-04 and ASTM E 1643 on four inches of clean, angular, open-
graded ⅜-inch gravel. The use of this system or other systems, materials, or techniques can
be considered, at the discretion of the post-tensioned slab designer, provided the system
reduces the vapor transmission rates to acceptable levels.
6.6.4. Lateral Earth Pressures
Backfill material behind walls should consist of granular “low” expansion potential
material (Expansion Index no greater than 50) and should be approved by the project
geotechnical engineer. The recommended active, passive and at rest lateral earth pressures,
which may be utilized for design of retaining walls with level and 2:1 backfill are as
follows:
Static Conditions
Compacted Artificial Fill, (afc90): phi = 32°, unit wt. = 130 pcf
Rankine Equivalent Fluid
Level Backfill Coefficients Pressure (psf/lin.ft.)
Coefficient of Active Pressure: Ka = 0.31 40
Coefficient of Passive Pressure: Kp = 3.25 420
Coefficient of at Rest Pressure: Ko = 0.47 61
Rankine Equivalent Fluid
2 : 1 Backfill Coefficients Pressure (psf/lin.ft.)
Coefficient of Active Pressure: Ka = 0.47 61
Coefficient of At Rest Pressure: Ko = 0.85 111
For rigid restrained walls it is recommended that “at-rest” values should be used. For
cantilever retaining walls which can undergo minor rotations active pressures can be used.
6.6.5. Seismic Earth Pressure
In addition to the above static pressures, unrestrained retaining walls with more than 6 feet
of backfill height should be designed to resist seismic loading as required by 2019 CBC.
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The seismic load can be modeled as a thrust load applied at a point 0.4H above the base of
the wall, where H is equal to the height of the wall. The seismic load (in pounds per lineal
foot of wall) may be calculated as follows:
Pe = ⅜ *γ*H2 *kh
where: Pe = Seismic thrust load
H = Height of the wall (feet)
γ = soil unit weight = 125 pounds per cubic foot (pcf)
kh = seismic pseudostatic coefficient = 0.5 * PGAM (PGAM see Table 4.5.3)
6.6.6. Retaining Wall Backfill and Drainage
Retaining walls should be waterproofed and adequately drained in order to limit hydrostatic
buildup behind walls. To relieve the potential for hydrostatic pressure, free draining
backfill (sand equivalent “SE” >20) and a heel drain should be placed (see Figure 3). Wall
drainage may be provided by a geosynthetic drainage composite such as TerraDrain®,
MiraDrain®, or equivalent, may be used. The drain should be placed continuously along
the back of the wall and connected to a 4-inch-diameter perforated pipe. The pipe should
be sloped at least 1% and should be surrounded by 1 cubic foot per foot of ¾-inch crushed
rock wrapped in suitable non-woven filter fabric (Mirafi® 140N or equivalent). Crushed
rock should meet the requirements defined in Section 200-1.2 of the latest edition of the
“Greenbook” Standard Specifications for Public Works Construction (Public Works
Standards, 2018). The drain should discharge through a solid pipe to an appropriate outlet.
FIGURE 3
Retaining Wall Backfill and Drainage
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6.7. Exterior Flatwork
Concrete flatwork should be designed utilizing 4-inch minimum thickness. Consideration should
be given to construct a thickened edge (scoop footing) at the perimeter of slabs and walkways
adjacent to landscape areas to minimize moisture variation below these improvements. The
thickened edge (scoop footing) should extend approximately 8 inches below concrete slabs and
should be a minimum of 6 inches wide. Weakened plane joints should be installed on walkways at
intervals of approximately 6 to 8 feet. Exterior slabs should be designed to withstand shrinkage of
the concrete. Consideration should be given to reinforcing any exterior flatwork.
6.8. Preliminary Pavement Design
For preliminary design and estimating purposes, the following pavement structural sections are
provided based on traffic indices (TI) of 5 for light traffic and 6 for truck access and an assumed
“R”-Value of 25.
TABLE 6.8
PRELIMINARY PAVEMENT SECTION
Traffic Index
(TI)
Asphaltic Concrete (AC)
(inches)
Class II Aggregate Base (AB)
(inches)
5.0 3 7
6.0 3 8
Portland cement concrete (PCC) pavement is recommended of trash enclosures and other heavy
traffic areas. The pavement structural section should consist of 6-inch thick PCC with a flexural
strength of 600 psi placed over compacted subgrade.
Subgrade soils and aggregate base materials should be compacted to at least 95 percent of
maximum density as determined by ASTM D 1557. Final pavement design should be based on
subgrade sampling and testing after grading completion.
6.9. Site Drainage
Roof, pad, and slope drainage should be diverted away from slopes and structures to suitable
discharge areas by non-erodible devices (e.g., gutters, downspouts, concrete swales, etc.). Positive
drainage adjacent to structures should be established and maintained. Positive drainage may be
accomplished by providing drainage away from the structure at a gradient of 2 percent or steeper
for a distance of 5 feet outside the building perimeter, and further maintained by a graded swale
leading to an appropriate outlet, in accordance with the recommendations of the project civil
engineer and/or landscape architect.
Surface drainage on the site should be provided so that water is not permitted to pond. A gradient
of 2 percent or steeper should be maintained over the pad area and drainage patterns should be
established to divert and remove water from the site to appropriate outlets. Drainage patterns
established at the time of grading should be maintained for the life of the project.
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6.10. Corrosion
Laboratory testing was performed on a representative sample of the onsite earth materials to
evaluate pH and electrical resistivity, as well as chloride and sulfate contents. The pH and electrical
resistivity tests were performed in accordance with California Test (CT) 643 and the sulfate and
chloride content tests were performed in accordance with CT 417 and CT 422, respectively. These
laboratory test results are presented in Appendix C.
The results of the corrosivity testing indicated an electrical resistivity value of 7,100 ohm-cm, soil
pH value of 8.3, chloride content of 321 parts per million (ppm) and sulfate content of 0.015 percent
(i.e., 148 ppm). Based on Caltrans (2018) corrosion criteria, the onsite soils would be classified as
non-corrosive, which is defined as soils with less than 500 ppm chlorides, less than 0.2 percent
sulfates, and pH higher than 5.5. We recommend that the corrosivity of site soils be further
evaluated by a corrosion engineer if detailed recommendations are needed.
6.11. Concrete Mix Design
Concrete in contact with soil or water that contains high concentrations of soluble sulfates can be
subject to chemical deterioration. Laboratory testing indicated sulfate exposure Class S0 per ACI
318. Although the sulfate content test results were not significantly high, due to the variability in
the onsite soils and the potential future use of reclaimed water at the site, we recommend that Type
II/V cement be used for concrete structures in contact with soil.
6.12. Buried Metallic Materials
The onsite soils are expected to be slightly corrosive to buried metallic materials. AGS recommends
minimally that the current standard of care be employed for protection of metallic construction
materials in contact with onsite soils or that consultation with an engineer specializing in corrosion
to determine specifications for protection of the construction materials.
7.0 FUTURE STUDY NEEDS
7.1. Plan Review
Once detailed grading and structural plans become available, they should be reviewed by AGS to
verify that the design recommendations presented are consistent with the proposed construction.
7.2. Observation during Construction
Geologic exposures afforded during grading operations provide the best opportunity to evaluate the
anticipated site geologic structure. Continuous geologic and geotechnical observations, testing, and
mapping should be provided throughout site development. Additional near-surface samples should
be collected by the geotechnical consultant during grading and subjected to laboratory testing. Final
design recommendations should be provided in a grading report based on the observation and test
results collected during grading.
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8.0 CLOSURE
The findings and recommendations in this report are based on the specific excavations, observations, and
tests results as noted herein. The findings are based on the review of the field and laboratory data combined
with an interpolation and extrapolation of conditions between and beyond the exploratory excavations. The
results reflect an interpretation of the direct evidence obtained. Services performed by AGS have been
conducted in a manner consistent with that level of care and skill ordinarily exercised by members of the
profession currently practicing in the same locality under similar conditions. No other representation, either
expressed or implied, and no warranty or guarantee is included or intended.
The recommendations presented in this report are based on the assumption that an appropriate level of field
review will be provided by geotechnical engineers and engineering geologists who are familiar with the
design and site geologic conditions. That field review shall be sufficient to confirm that geotechnical and
geologic conditions exposed during grading are consistent with the geologic representations and
corresponding recommendations presented in this report. If the project description varies from what is
described in this report, AGS must be consulted regarding the applicability of, and the necessity for, any
revisions to the recommendations presented herein. AGS should review structural plans to verify whether
the recommendations presented herein are incorporated into the design. AGS accepts no liability for any
use of its recommendations if the project description or final design varies and AGS is not consulted
regarding the changes.
The data, opinions, and recommendations of this report are applicable to the specific design of this project
as discussed in this report. They have no applicability to any other project or to any other location, and any
and all subsequent users accept any and all liability resulting from any use or reuse of the data, opinions,
and recommendations without the prior written consent of AGS.
AGS has no responsibility for construction means, methods, techniques, sequences, or procedures, or for
safety precautions or programs in connection with the construction, for the acts or omissions of the
CONTRACTOR, or any other person performing any of the construction, or for failure of any of them to
carry out the construction in accordance with the final design drawings and specifications.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIX A
REFERENCES
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REFERENCES
Advanced Geotechnical Solutions Inc., 2021, “Due Diligence Geotechnical Study, Proposed Multi-Family
Residential Development, 7200-7590 Ponto Drive, Carlsbad, California”, dated December 3, 2021,
Report No. 2107-12-B-2R.
ACI Committee 318, 2014, Building Code Requirements for Structural Concrete (ACI318-14) and
Commentary (ACI 318R-14), American Concrete Institute, Farmington Hills, Michigan.
California Building Standards Commission, 2019, 2019 California Building Code, Title 24, Part 2, Volumes
1 and 2.
California Division of Mines and Geology, 1986 (revised), Guidelines to geologic and seismic reports:
DMG Note 42, 2 p.
California Geological Survey, 2008, Guidelines for Evaluating and Mitigating Seismic Hazards in
California: Department of Conservation, Special Publication 117A, 108 p.
California Water Boards, Geotracker web site, depth to groundwater,
http://geotracker.waterboards.ca.gov/gama/gamamap/public/default.asp
City of Carlsbad, 2021, City of Carlsbad BMP Design Manual, dated February 16, 2016, revised September
1, 2021.
County of San Diego Office of Emergency Services, 2010, Draft Liquefaction Map, County of San Diego
Hazard Mitigation Plan, dated August 2010.
FEMA, 2019, Flood Insurance Rate Map, San Diego County, Map Numbers 06073C1027H, Revised
December 20, 2019, Scale: 1”=500’.
Hunsaker & Associates San Diego, Inc., 2022, Design Study for Ponto Road, City of Carlsbad, California,
30-scale, Sheet 1 of 1, print dated February 24, 2022.
Jennings, C. W., 1985, An explanatory text to accompany the 1:750,000 scale fault and geologic map of
California: California Division of Mines and Geology, special publication 42, revised 1985, 24 p.
Kennedy, M.P., and Tan, S.S., 2007, Geologic Map of the Oceanside 30' x 60' Quadrangle, California,
California Geological Survey, Preliminary Geologic Maps, Scale 1:100,000.
State of California Water Boards, 2022, http://geotracker.waterboards.ca.gov/
Southern California Earthquake Center, 2002, Recommended Procedures for Implementation of DMG
Special Publication 117 Guidelines for Analyzing and Mitigating Liquefaction Hazards in
California, dated June 2002.
United States Geological Survey, 2021, Seismic Design Maps, https://seismicmaps.org/ developed by
SEAOC and OSHPD.
United States Geological Survey, 2021, Unified Hazards Tool,
https://earthquake.usgs.gov/hazards/interactive
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIX B
SUBSURFACE EXPLORATION
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Date Excavated: 1/31/2022
Logged by: FE
Equipment: Backhoe
LOG OF EXPLORATORY EXCAVATIONS
Excavation Depth
No. (ft.) USCS Description
TP-1
0.0 – 3.5
3.5 – 8.0
SP
SP
CH
SC
Artificial Fill - Undocumented (afu):
SAND; reddish brown, slightly moist, medium dense, fine-
to medium-grained.
@ 3 ft. 1-inch thick black organic layer; discontinuous.
Old Paralic Deposits (Qop):
SAND; light grayish brown, slightly moist, dense, fine-
grained, friable,
@ 4.5 ft. SILTY CLAY; light olive, very moist, stiff,
@ 6 ft. abundant iron oxide staining.
@ 7 ft. grades to CLAYEY SAND.
TOTAL DEPTH 8 ft.
NO WATER, NO CAVING
Excavation Depth
No. (ft.) USCS Description
TP-2
0.0 – 1.5.
1.5 – 6.0
SM
SM
CH
Alluvium (Qal):
SILTY SAND; reddish brown, moist, loose, fine-grained,
visible porosity, lag deposit at base of Qal.
Old Paralic Deposits (Qop):
SILTY SAND; light yellow, slightly moist, dense, fine-
grained.
@ 4 ft. SILTY CLAY; olive, very moist, very stiff, highly
expansive; some fine-grained sand.
TOTAL DEPTH 6 ft.
NO WATER, NO CAVING
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LOG OF EXPLORATORY EXCAVATIONS (continued)
Excavation Depth
No. (ft.) USCS Description
TP-3
0.0 – 1.5
1.5 – 4.0
4.0 – 6.0
SM
SM
CH
Artificial Fill - Undocumented (afu):
SILTY SAND; brown, slightly moist, medium dense, fine-
to medium-grained.
Alluvium (Qal):
SILTY SAND; reddish brown, slightly moist, dense, fine-
grained.
@ 4 ft. some lag deposit pebbles.
Old Paralic Deposits (Qop):
SILTY CLAY; olive, very moist, very stiff, highly
expansive; with iron oxide staining.
TOTAL DEPTH 6 ft.
NO WATER NO CAVING
Excavation Depth
No. (ft.) USCS Description
TP-4
0.0 – 9.0
9.0 – 13.5
SM
ML
SM
Artificial Fill - Undocumented (afu):
SILTY SAND: yellowish brown, dry, loose, fine-grained;
with abundant concrete fragments to 6-inch size; one
concrete fragment is 3 ft. by 2.5 ft. by 9 in.; some asphalt.
@ 1.5 ft. SANDY SILT layer; olive, moist, medium dense.
Old Paralic Deposits (Qop):
SILTY SAND; reddish brown to yellowish brown, slightly
moist, dense, fine-grained, trace rounded volcanic gravel to
2-inch diameter.
@ 11 ft. reddish yellow
TOTAL DEPTH 13.5 ft.
NO WATER, NO CAVING
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LOG OF EXPLORATORY EXCAVATIONS (continued)
Excavation Depth
No. (ft.) USCS Description
TP-5
0.0 – 2.5
2.5 – 5.0
5.0 - 12.5
SM
SM
SM
SP
Artificial Fill - Undocumented (afu):
SILTY SAND: reddish brown, moist, medium dense, fine
grained, abundant concrete chunks.
@ 2.5 ft. ±2.5 inch thick asphalt pavement, continuous layer.
Alluvium (Qal):
SILTY SAND; reddish brown, medium dense, fine-grained,
friable.
Old Paralic Deposits (Qop):
SILTY SAND; yellowish brown, slightly moist, dense, fine-
grained.
@ 11 ft. SAND; light olive, slightly moist, friable.
TOTAL DEPTH 12.5 ft.
NO WATER, NO CAVING
Excavation Depth
No. (ft.) USCS Description
TP-6
0.0 – 3.0
3.0 – 6.0
SM
SM
Artificial Fill - Undocumented (afu):
SILTY SAND: grayish brown to reddish brown, dry, loose,
fine-grained.
@ 2.5 ft. 3-inch-thick asphalt pavement, continuous layer.
@ 2.75 ft. some gravel and coarse-grained sand below AC.
Old Paralic Deposits (Qop):
SILTY SAND; reddish brown, slightly moist, dense, fine-
grained, some secondary clay development.
@ 5 ft. moist, friable.
TOTAL DEPTH 6 ft.
NO WATER, NO CAVING
March 16, 2022 Page B-4
P/W 2107-12 Report No. 2107-12-B-2
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
LOG OF EXPLORATORY EXCAVATIONS (continued)
Excavation Depth
No. (ft.) USCS Description
TP-7
0.0 – 3.5
3.5 – 7.0
SM
SM
Alluvium (Qal):
SILTY SAND; light brown, moist, medium dense, fine-
grained
@ 3.5 ft. roots.
Old Paralic Deposits (Qop):
SILTY SAND; light yellow, moist, dense, fine-grained,
some secondary clay development.
TOTAL DEPTH 7 ft.
NO WATER, NO CAVING
Excavation Depth
No. (ft.) USCS Description
TP-8
0.0 – 2.5
2.5 – 6.0
6.0 – 12.5
SM
SM
SM
SP
Artificial Fill - Undocumented (afu):
SILTY SAND: reddish brown, slightly moist, loose, fine-
grained, abundant chain link fence debris and concrete
chunks to 4-inch diameter.
Alluvium (Qal):
SILTY SAND; reddish brown, moist, medium dense, fine-
grained, friable.
Old Paralic Deposits (Qop):
SILTY SAND; yellowish brown, moist, dense, fine-grained.
@ 11 ft. SAND; olive with abundant iron oxide staining,
moist, dense, fine-grained, some silt.
TOTAL DEPTH 12.5 ft.
NO WATER, NO CAVING
March 16, 2022 Page B-5
P/W 2107-12 Report No. 2107-12-B-2
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
LOG OF EXPLORATORY EXCAVATIONS (continued)
Excavation Depth
No. (ft.) USCS Description
TP-9
0.0 – 0.5
0.5 – 3.5
3.5
SM
SM
SM
Artificial Fill - Undocumented (afu):
SILTY SAND: yellowish brown, slightly moist, medium
dense, fine-grained, some clayey silt clasts to 2-inch size.
Alluvium (Qal):
SILTY SAND; yellowish brown, slightly moist, loose to
medium dense, fine-grained, friable.
@ 3 ft. 2-inch wide trench for telephone wire bundle in Qal.
Old Paralic Deposits (Qop):
SILTY SAND; yellowish brown, slightly moist, dense, fine-
grained,
TOTAL DEPTH 3.5 ft.
NO WATER, NO CAVING
Excavation Depth
No. (ft.) USCS Description
TP-10
0.0 – 5.0
5.0 – 5.5
SM
SC
Artificial Fill - Undocumented (afu):
2-inches AC over
SILTY SAND; reddish brown, very moist, loose, fine-
grained, some clay; with abundant debris (concrete with
rebar, carpet, plastic, metal beam).
2.5-inch void below 18-inch footing for storage structure.
(Pavement settlement)
Old Paralic Deposits (Qop):
CLAYEY SAND; olive brown to olive gray mottled, very
moist, medium dense to dense, fine grained.
@ 5 ft. moist, friable.
TOTAL DEPTH 5.5 ft.
NO WATER, NO CAVING
March 16, 2022 Page B-6
P/W 2107-12 Report No. 2107-12-B-2
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
Date Excavated: 1/31/2022
Logged by: FE
Equipment: Hand Auger
LOG OF PERCOLATION TEST BORINGS
Excavation Depth
No. (ft.) USCS Description
P-1
0.0 – 3.0
3.0 – 5.0
SM
CH
Artificial Fill - Undocumented (afu):
2.5-inches AC over
SILTY SAND; brown to reddish brown, very moist, loose,
fine-grained, some rounded cobbles.
Old Paralic Deposits (Qop):
CLAY; olive brown to olive gray, mottled, very moist, stiff,
highly expansive.
TOTAL DEPTH 5 ft.
NO WATER, NO CAVING
Excavation Depth
No. (ft.) USCS Description
P-2
0.0 – 4.0
4.0 – 5.5
SM
SC
Artificial Fill - Undocumented (afu):
2-inches of AC over
SILTY SAND; reddish brown, very moist, loose, fine
grained.
Old Paralic Deposits (Qop):
SILTY SAND; grayish brown to reddish yellow, mottled,
very moist, dense, fine-grained.
TOTAL DEPTH 5.5 ft.
NO WATER, NO CAVING
March 16, 2022 Page B-7
P/W 2107-12 Report No. 2107-12-B-2
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
LOG OF PERCOLATION TEST BORINGS (continued)
Excavation Depth
No. (ft.) USCS Description
P-3
0.0 – 1.0
1.0 – 5.0
SM
SP-SM
Topsoil:
SILTY SAND; grayish brown, loose, fine-grained.
Old Paralic Deposits (Qop):
SILTY SAND to SAND with SILT; yellowish brown, moist,
medium dense, fine-grained.
TOTAL DEPTH 5 ft.
NO WATER, NO CAVING
Excavation Depth
No. (ft.) USCS Description
P-4
0.0 – 2.0
2.0 – 5.5
SM
SM
SP-SM
Artificial Fill – Undocumented (afu):
SILTY SAND; gray to yellowish brown, moist, loose, fine-
grained.
Old Paralic Deposits (Qop):
SILTY SAND; reddish brown, moist, medium dense, fine
grained.
@ 3.5 ft. SILTY SAND to SAND with SILT; medium
dense, moist fine grained.
TOTAL DEPTH 5.5 ft.
NO WATER, NO CAVING
Excavation Depth
No. (ft.) USCS Description
P-5
0.0 – 4.0
4.0 – 5.5
SM
SM
Artificial Fill – Undocumented (afu):
SILTY SAND; moist, loose, fine- to medium-grained, some
gravel and small pieces of concrete.
Old Paralic Deposits (Qop):
SILTY SAND; reddish brown, moist, medium dense, fine
grained.
TOTAL DEPTH 5.5 ft.
NO WATER, NO CAVING
OLD PARALIC DEPOSITS (Qop)
Silty SAND, fine-grained, yellowish brown, dry, loose, someclay and coarse-grained sand.
@ 3 ft. moist.
@ 4 ft. dense.
@ 5 ft. some gray mottling, medium dense.
@ 10 ft. some siltstone clasts to 0.5-inch size.
Clayey SAND, yellowish brown to olive, mottled, moist, very
dense, some silt.
Clayey to silty SAND, fine- to coarse-grained, reddish yellow
to grayish brown, moist, very dense, some rounded gravel to0.25-inch size.
SAND, fine- to coarse-grained, light gray, moist, very dense.
Total Depth = 26.5 ft.
No groundwater. No caving.Backfilled in accordance with SDCDEH requirements.
5-6-11
(17)
8-12-17
(29)
13-17-20
(37)
11-21-50/4"
15-27-39
(66)
MC
BU
MC
SPT
MC
SPT
106
103
114
2.2
9.6
7.9
10
41
45
SM
SC
SC-SM
SP
EIMAXRDSCORR
DS
NOTES
GROUND ELEVATION 44 ft
LOGGED BY FE
DRILLING METHOD Hollow Stem Auger
HOLE SIZE 8
DRILLING CONTRACTOR Pacific Drilling GROUND WATER LEVELS:
CHECKED BY PJD
DATE STARTED 9/20/21 COMPLETED 9/20/21
AT TIME OF DRILLING ---
AT END OF DRILLING ---
AFTER DRILLING ---
MATERIAL DESCRIPTION
BL
O
W
CO
U
N
T
S
(N
V
A
L
U
E
)
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
10
15
20
25
SA
M
P
L
E
T
Y
P
E
NU
M
B
E
R
LI
Q
U
I
D
LI
M
I
T
PL
A
S
T
I
C
LI
M
I
T
PL
A
S
T
I
C
I
T
Y
IN
D
E
X
ATTERBERGLIMITS
PL
A
S
T
I
C
I
T
Y
IN
D
E
X
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
SA
T
U
R
A
T
I
O
N
(
%
)
FI
N
E
S
C
O
N
T
E
N
T
(%
)
US
C
S
OT
H
E
R
T
E
S
T
S
PAGE 1 OF 1
BORING NUMBER B-1
CLIENT H.G. Fenton Company
PROJECT NUMBER 2107-12
PROJECT NAME Proposed Multi-Family Residential Development
PROJECT LOCATION 7294 to 7590 Ponto Drive, Carlsbad, CA
AG
S
B
O
R
I
N
G
L
O
G
V
2
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
1
0
/
2
2
/
2
1
1
4
:
1
3
-
Z
:
\
P
R
O
J
E
C
T
F
I
L
E
S
\
2
1
0
7
-
1
2
H
G
F
E
N
T
O
N
P
O
N
T
O
D
R
C
A
R
L
S
B
A
D
\
2
1
0
7
-
1
2
L
A
B
L
O
G
S
\
2
1
0
7
-
1
2
B
O
R
I
N
G
L
O
G
S
.
G
P
J
ASPHALT CONCRETE 2"AC
ARTIFICIAL FILL - UNDOCUMENTED (afu)Silty fine-grained SAND, dark brown, moist, medium dense;some fine gravel.
OLD PARALIC DEPOSITS (Qop)
Silty SAND, fine- to coarse-grained, yellowish brown, moist,medium dense, some clay.
Clayey SAND, fine- to coarse-grained, reddish yellow and
olive, moist, dense, some rounded gravel to 0.5-inch size.
SAND, fine-grained, light gray, moist, very dense, some
clay.
@ 20 ft. saturated.
@ 20.5 ft. groundwater.
Total Depth = 21 ft.
Groundwater encountered at 20.5 ft. during drilling.No caving.Backfilled in accordance with SDCDEH requirements.
7-12-22
(34)
14-22-36
(58)
24-35-50
(85)
28-50
BU
MC
MC
SPT
MC
116
115
116
10.6
9.6
13.8
63
56
81
SM
SM
SC
SP
CONS
CONS
NOTES
GROUND ELEVATION 42 ft
LOGGED BY FE
DRILLING METHOD Hollow Stem Auger
HOLE SIZE 8
DRILLING CONTRACTOR Pacific Drilling GROUND WATER LEVELS:
CHECKED BY PJD
DATE STARTED 9/20/21 COMPLETED 9/20/21
AT TIME OF DRILLING 20.50 ft / Elev 21.50 ft
AT END OF DRILLING 20.50 ft / Elev 21.50 ft
AFTER DRILLING ---
MATERIAL DESCRIPTION
BL
O
W
CO
U
N
T
S
(N
V
A
L
U
E
)
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
10
15
20
SA
M
P
L
E
T
Y
P
E
NU
M
B
E
R
LI
Q
U
I
D
LI
M
I
T
PL
A
S
T
I
C
LI
M
I
T
PL
A
S
T
I
C
I
T
Y
IN
D
E
X
ATTERBERGLIMITS
PL
A
S
T
I
C
I
T
Y
IN
D
E
X
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
SA
T
U
R
A
T
I
O
N
(
%
)
FI
N
E
S
C
O
N
T
E
N
T
(%
)
US
C
S
OT
H
E
R
T
E
S
T
S
PAGE 1 OF 1
BORING NUMBER B-2
CLIENT H.G. Fenton Company
PROJECT NUMBER 2107-12
PROJECT NAME Proposed Multi-Family Residential Development
PROJECT LOCATION 7294 to 7590 Ponto Drive, Carlsbad, CA
AG
S
B
O
R
I
N
G
L
O
G
V
2
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
1
0
/
2
2
/
2
1
1
4
:
1
3
-
Z
:
\
P
R
O
J
E
C
T
F
I
L
E
S
\
2
1
0
7
-
1
2
H
G
F
E
N
T
O
N
P
O
N
T
O
D
R
C
A
R
L
S
B
A
D
\
2
1
0
7
-
1
2
L
A
B
L
O
G
S
\
2
1
0
7
-
1
2
B
O
R
I
N
G
L
O
G
S
.
G
P
J
ARTIFICIAL FILL - UNDOCUMENTED (afu)
Silty fine-grained SAND, brown to dark brown, moist,medium dense; some fine gravel.
OLD PARALIC DEPOSITS (Qop)
Clayey to silty SAND, fine- to coarse-grained, yellowishbrown and olive, mottled, moist, very dense.
@ 10 ft. same.
@ 16 ft. micaceous.
Total Depth = 16.5 ft.
No groundwater. No caving.Backfilled in accordance with SDCDEH requirements.
11-35-50
(85)
11-27-
41/3"
MC
MC
SPT
131
122
7.7
10.9
73
77
SM
SC-SM
NOTES
GROUND ELEVATION 44 ft
LOGGED BY FE
DRILLING METHOD Hollow Stem Auger
HOLE SIZE 8
DRILLING CONTRACTOR Pacific Drilling GROUND WATER LEVELS:
CHECKED BY PJD
DATE STARTED 9/20/21 COMPLETED 9/20/21
AT TIME OF DRILLING ---
AT END OF DRILLING ---
AFTER DRILLING ---
MATERIAL DESCRIPTION
BL
O
W
CO
U
N
T
S
(N
V
A
L
U
E
)
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
10
15
SA
M
P
L
E
T
Y
P
E
NU
M
B
E
R
LI
Q
U
I
D
LI
M
I
T
PL
A
S
T
I
C
LI
M
I
T
PL
A
S
T
I
C
I
T
Y
IN
D
E
X
ATTERBERGLIMITS
PL
A
S
T
I
C
I
T
Y
IN
D
E
X
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
SA
T
U
R
A
T
I
O
N
(
%
)
FI
N
E
S
C
O
N
T
E
N
T
(%
)
US
C
S
OT
H
E
R
T
E
S
T
S
PAGE 1 OF 1
BORING NUMBER B-3
CLIENT H.G. Fenton Company
PROJECT NUMBER 2107-12
PROJECT NAME Proposed Multi-Family Residential Development
PROJECT LOCATION 7294 to 7590 Ponto Drive, Carlsbad, CA
AG
S
B
O
R
I
N
G
L
O
G
V
2
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
1
0
/
2
2
/
2
1
1
4
:
1
3
-
Z
:
\
P
R
O
J
E
C
T
F
I
L
E
S
\
2
1
0
7
-
1
2
H
G
F
E
N
T
O
N
P
O
N
T
O
D
R
C
A
R
L
S
B
A
D
\
2
1
0
7
-
1
2
L
A
B
L
O
G
S
\
2
1
0
7
-
1
2
B
O
R
I
N
G
L
O
G
S
.
G
P
J
ASPHALT CONCRETE 3"AC
ARTIFICIAL FILL - UNDOCUMENTED (afu)Clayey fine-grained SAND, brown, moist, medium dense.
OLD PARALIC DEPOSITS (Qop)
Clayey fine-grained SAND, brown, moist, medium dense;some black manganese oxide nodules.
@ 10 ft. very dense.
Interbedded sandy SILT and silty SAND, fine-grained, light
olive to yellowish brown, moist, dense.
@ 18 ft. Clayey fine- to medium-grained SAND, light gray,
moist, very dense.
Total Depth = 20.75 ft.No groundwater. No caving.
Backfilled in accordance with SDCDEH requirements.
5-10-20
(30)
31-50
38-50/3"
MC
MC
BU
SPT
MC
122
125
120
10.9
9.4
11.9
76
73
79
SC
SC
SM
SC
NOTES
GROUND ELEVATION 45 ft
LOGGED BY FE
DRILLING METHOD Hollow Stem Auger
HOLE SIZE 8
DRILLING CONTRACTOR Pacific Drilling GROUND WATER LEVELS:
CHECKED BY PJD
DATE STARTED 9/20/21 COMPLETED 9/20/21
AT TIME OF DRILLING ---
AT END OF DRILLING ---
AFTER DRILLING ---
MATERIAL DESCRIPTION
BL
O
W
CO
U
N
T
S
(N
V
A
L
U
E
)
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
10
15
20
SA
M
P
L
E
T
Y
P
E
NU
M
B
E
R
LI
Q
U
I
D
LI
M
I
T
PL
A
S
T
I
C
LI
M
I
T
PL
A
S
T
I
C
I
T
Y
IN
D
E
X
ATTERBERGLIMITS
PL
A
S
T
I
C
I
T
Y
IN
D
E
X
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
SA
T
U
R
A
T
I
O
N
(
%
)
FI
N
E
S
C
O
N
T
E
N
T
(%
)
US
C
S
OT
H
E
R
T
E
S
T
S
PAGE 1 OF 1
BORING NUMBER B-4
CLIENT H.G. Fenton Company
PROJECT NUMBER 2107-12
PROJECT NAME Proposed Multi-Family Residential Development
PROJECT LOCATION 7294 to 7590 Ponto Drive, Carlsbad, CA
AG
S
B
O
R
I
N
G
L
O
G
V
2
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
1
0
/
2
2
/
2
1
1
4
:
1
3
-
Z
:
\
P
R
O
J
E
C
T
F
I
L
E
S
\
2
1
0
7
-
1
2
H
G
F
E
N
T
O
N
P
O
N
T
O
D
R
C
A
R
L
S
B
A
D
\
2
1
0
7
-
1
2
L
A
B
L
O
G
S
\
2
1
0
7
-
1
2
B
O
R
I
N
G
L
O
G
S
.
G
P
J
ARTIFICIAL FILL - UNDOCUMENTED (afu)
Silty fine-grained SAND, light yellowish brown, dry, loose tomedium dense; some fine gravel.
@ 5 ft. concrete clasts with large voids. No recovery.
OLD PARALIC DEPOSITS (Qop)
SAND to silty SAND, fine-grained, reddish to yellowishbrown, dry, medium dense.
@ 10 ft. very dense.
@ 14 ft. same, fine- to coarse-grained, light gray, dense.
@ 16.5 ft. moist.
Total Depth = 16.5 ft.
No groundwater. No caving.Backfilled in accordance with SDCDEH requirements.
40
28-49-
22/2"
7-14-15
(29)
MC
MC
SPT
SM
SP-SM
NOTES
GROUND ELEVATION 48 ft
LOGGED BY FE
DRILLING METHOD Hollow Stem Auger
HOLE SIZE 8
DRILLING CONTRACTOR Pacific Drilling GROUND WATER LEVELS:
CHECKED BY PJD
DATE STARTED 9/20/21 COMPLETED 9/20/21
AT TIME OF DRILLING ---
AT END OF DRILLING ---
AFTER DRILLING ---
MATERIAL DESCRIPTION
BL
O
W
CO
U
N
T
S
(N
V
A
L
U
E
)
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
10
15
SA
M
P
L
E
T
Y
P
E
NU
M
B
E
R
LI
Q
U
I
D
LI
M
I
T
PL
A
S
T
I
C
LI
M
I
T
PL
A
S
T
I
C
I
T
Y
IN
D
E
X
ATTERBERGLIMITS
PL
A
S
T
I
C
I
T
Y
IN
D
E
X
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
SA
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PAGE 1 OF 1
BORING NUMBER B-5
CLIENT H.G. Fenton Company
PROJECT NUMBER 2107-12
PROJECT NAME Proposed Multi-Family Residential Development
PROJECT LOCATION 7294 to 7590 Ponto Drive, Carlsbad, CA
AG
S
B
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ARTIFICIAL FILL - UNDOCUMENTED (afu)
Concrete and asphalt fragments with reinforcement steelbars.
@ 2.5 ft. refusal on concrete clasts.
Total Depth = 2.5 ft. Refusal.
No groundwater. No caving.Backfilled in accordance with SDCDEH requirements.
NOTES
GROUND ELEVATION 47 ft
LOGGED BY FE
DRILLING METHOD Hollow Stem Auger
HOLE SIZE 8
DRILLING CONTRACTOR Pacific Drilling GROUND WATER LEVELS:
CHECKED BY PJD
DATE STARTED 9/20/21 COMPLETED 9/20/21
AT TIME OF DRILLING ---
AT END OF DRILLING ---
AFTER DRILLING ---
MATERIAL DESCRIPTION
BL
O
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CO
U
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(N
V
A
L
U
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)
GR
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P
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P
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(f
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)
0 SA
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ATTERBERGLIMITS
PL
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PAGE 1 OF 1
BORING NUMBER B-6
CLIENT H.G. Fenton Company
PROJECT NUMBER 2107-12
PROJECT NAME Proposed Multi-Family Residential Development
PROJECT LOCATION 7294 to 7590 Ponto Drive, Carlsbad, CA
AG
S
B
O
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G
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ARTIFICIAL FILL - UNDOCUMENTED (afu)
Silty fine-grained SAND, yellowish brown, dry, loose; someasphalt fragments.
OLD PARALIC DEPOSITS (Qop)
Silty SAND, fine-grained, light yellowish brown, dry, dense.
@ 5 ft. damp.
Total Depth = 5 ft.
No groundwater. No caving.Backfilled in accordance with SDCDEH requirements.
SM
SP-SM
NOTES
GROUND ELEVATION 47 ft
LOGGED BY FE
DRILLING METHOD Hollow Stem Auger
HOLE SIZE 8
DRILLING CONTRACTOR Pacific Drilling GROUND WATER LEVELS:
CHECKED BY PJD
DATE STARTED 9/20/21 COMPLETED 9/20/21
AT TIME OF DRILLING ---
AT END OF DRILLING ---
AFTER DRILLING ---
MATERIAL DESCRIPTION
BL
O
W
CO
U
N
T
S
(N
V
A
L
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)
GR
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PAGE 1 OF 1
BORING NUMBER B-7
CLIENT H.G. Fenton Company
PROJECT NUMBER 2107-12
PROJECT NAME Proposed Multi-Family Residential Development
PROJECT LOCATION 7294 to 7590 Ponto Drive, Carlsbad, CA
AG
S
B
O
R
I
N
G
L
O
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2
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIX C
LABORATORY TEST RESULTS
EXPANSION INDEX - ASTM D4829 AGS FORM E-6
Project Name:HG Fenton Excavation/Tract:B-1
Location:Carlsbad Depth:7-12 ft
P/W:2107-12 Description:SM
Date:10/12/21 Tested by:FV
Checked by:AB
Expansion Index - ASTM D4829
Initial Dry Density (pcf):120.1
Initial Moisture Content (%):7.6
Initial Saturation (%):50.9
Final Dry Density (pcf):120.5
Final Moisture Content (%):13.0
Final Saturation (%):88.4
Expansion Index:0
Potential Expansion:Very Low
ASTM D4829 - Table 5.3
Expansion Index
0 - 20
21 - 50
51 - 90
91 - 130
>130 Very High
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
Potential Expansion
Very Low
Low
Medium
High
2107-12_EI_B1_7-12 ft_10-12-2021_FV.xlsx
EXPANSION INDEX - ASTM D4829 AGS FORM E-6
Project Name: HG Fenton Excavation/Tract:TP-2
Location:Carlsbad Depth/Lot:4 ft
P/W:2107-12 Description:Light Brn CH
Date:2/10/22 Tested by:FV
Checked by:AB
Expansion Index - ASTM D4829
Initial Dry Density (pcf):97.4
Initial Moisture Content (%):13.0
Initial Saturation (%):48.1
Final Dry Density (pcf):87.2
Final Moisture Content (%):32.6
Final Saturation (%):94.5
Expansion Index:117
Potential Expansion:High
ASTM D4829 - Table 5.3
Expansion Index
0 - 20
21 - 50
51 - 90
91 - 130
>130 Very High
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
Potential Expansion
Very Low
Low
Medium
High
2107-12_EI_TP-2_4 ft-02-10-2022_FV.xlsx
AGS Form E-2
ATTERBERG LIMITS - ASTM D4318
Project Name:HG Fenton Excavation:TP-2
Location:Carlsbad Depth:4 ft
Project No:2107-12 Description:Light Brn CH
Date:2/7/2022 By:FV
LIQUID LIMIT PLASTIC LIMIT
Can No.15 1 5 103 104
Wt. wet soil+can (g)19.45 19.41 19.39 57.50 57.54
Wt. dry soil+can (g)16.41 16.31 16.25 56.40 56.38
Wt. can (g)11.27 11.27 11.30 51.45 51.04
Wt. mosture (g)3.04 3.10 3.14 1.10 1.16
Wt. dry soil (g)5.14 5.04 4.95 4.95 5.34
Water Content %59.14 61.51 63.43 22.22 21.72
No. of Blows 35 25 18
Liquid Limit (LL)62 Plastic Limit (PL)22 Plasticity Index (PI)40
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110
PL
A
S
T
I
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I
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Y
I
N
D
E
X
(
P
I
)
LIQUID LIMIT (LL)
PLASTICITY CHART
MH or OH
CL-ML ML or OL
40
45
50
55
60
65
70
75
80
10 50
MO
I
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O
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(
%
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NUMBER OF BLOWS, N
LIQUID LIMIT
2107-12_Atterberg_TP-2_4 ft_02-07-2022_FV.xlsx
CONSOLIDATION - ASTM D2435 AGS Form E-3
Project Name:HG Fenton Excavation:B-2
Location:Carlsbad Depth:5 ft
Project No:2107-12 Description:SM
Date:By:FV
Test Data Before Test After Test
Water Content, w 10.6%15.2%
Void Ratio, e 0.450 0.414
Saturation, S 63%99%
Dry Density (pcf)116.2 119.2
Wet Density (pcf)128.5 137.3
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
9/29/21
-7
-6
-5
-4
-3
-2
-1
0
1
0.1 1 10 100
Co
n
s
o
l
i
d
a
t
i
o
n
(
%
)
Normal Pressure (ksf)
Consolidation-Pressure Curve
CONSOLIDATION - ASTM D2435 AGS Form E-3
Project Name:HG Fenton Excavation:B-2
Location:Carlsbad Depth:10 ft
Project No:2107-12 Description:SC
Date:By:FV
Test Data Before Test After Test
Water Content, w 9.6%15.1%
Void Ratio, e 0.464 0.437
Saturation, S 56%93%
Dry Density (pcf)115.1 117.2
Wet Density (pcf)126.2 134.9
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
9/29/21
-7
-6
-5
-4
-3
-2
-1
0
1
0.1 1 10 100
Co
n
s
o
l
i
d
a
t
i
o
n
(
%
)
Normal Pressure (ksf)
Consolidation-Pressure Curve
MAXIMUM DENSITY - ASTM D1557 AGS FORM E-8
Project Name:HG Fenton Excavation:B-1
Location:Carlsbad Depth:7-12 ft
P/W No.:2107-12 Soil Type:SM
Date:Tested by:RT
Checked by:AB
Method:A Oversize Retained:0 %
Point No.1 2 3 4
Dry Density (pcf)127.2 134.7 132.0 126.8
Moisture Content (%)5.7 7.9 9.6 11.6
Corrected Max. Dry Density 134.8 pcf Corrected Moisture 8.1 %
Max. Dry Density 134.8 pcf Optimum Moisture 8.1 %
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
10-2021
100.0
105.0
110.0
115.0
120.0
125.0
130.0
135.0
140.0
0.0 5.0 10.0 15.0 20.0 25.0 30.0
DR
Y
D
E
N
S
I
T
Y
(
p
c
f
)
MOISTURE (%)
MAXIMUM DENSITY CURVE
Test Curve
Zero Air Voids Curves
SG=2.6
SG=2.7
SG=2.8
Project Name:HG Fenton Excavation:B-1
Location:Carlsbad Depth:7-12 ft
Project No.:2107-12 Tested by:FV
Date:Reviewed by:AB
Samples Tested 1 2 3 Soil Type:SM
Intial Moisture (%)7.8 7.8 7.8 Test:Remolded 90%
Initial Dry Density (pcf)121.5 121.5 121.6 Method:Drained
Normal Stress (psf)1000 2000 4000 Consolidation:Yes
Peak Shear Stress (psf)948 1332 2556 Saturation:Yes
Ult. Shear Stress (psf)732 1320 2544 Shear Rate (in/min):0.01
Strength Parameters Peak Ultimate
Friction Angle, phi (deg)29 31
Cohesion (psf)350 150
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
DIRECT SHEAR - ASTM D3080
10/14/2021
-0.02
-0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.00 0.10 0.20 0.30
Ve
r
t
i
c
a
l
D
e
f
o
r
m
a
t
i
o
n
(
i
n
)
Displacement (in)
Vertical Deformation v. Displacement
4000
2000
10000
500
1000
1500
2000
2500
3000
0.00 0.10 0.20 0.30
Sh
e
a
r
S
t
r
e
s
s
(
p
s
f
)
Displacement (in)
Shear Stress v. Displacement
4000
2000
1000
0
500
1000
1500
2000
2500
3000
0 500 1000 1500 2000 2500 3000 3500 4000 4500
Sh
e
a
r
S
t
r
e
s
s
(
p
s
f
)
Normal Stress (psf)
Peak
Peak
Ultimate
Ultimate
Project Name:HG Fenton Excavation:B-1
Location:Carlsbad Depth:10 ft
Project No.:2107-02 Tested by:FV
Date:Reviewed by:AB
Samples Tested 1 2 3 Soil Type:SM
Intial Moisture (%)9.6 9.6 9.6 Test:Undisturbed
Initial Dry Density (pcf)104.7 101.4 103.0 Method:Drained
Normal Stress (psf)1000 2000 4000 Consolidation:Yes
Peak Shear Stress (psf)840 1560 2736 Saturation:Yes
Ult. Shear Stress (psf)672 1536 2592 Shear Rate (in/min):0.01
Strength Parameters Peak Ultimate
Friction Angle, phi (deg)32 32
Cohesion (psf)225 100
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
DIRECT SHEAR - ASTM D3080
9/30/2021
-0.02
-0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.00 0.10 0.20 0.30
Ve
r
t
i
c
a
l
D
e
f
o
r
m
a
t
i
o
n
(
i
n
)
Displacement (in)
Vertical Deformation v. Displacement
4000
2000
10000
500
1000
1500
2000
2500
3000
0.00 0.10 0.20 0.30
Sh
e
a
r
S
t
r
e
s
s
(
p
s
f
)
Displacement (in)
Shear Stress v. Displacement
4000
2000
1000
0
500
1000
1500
2000
2500
3000
0 500 1000 1500 2000 2500 3000 3500 4000 4500
Sh
e
a
r
S
t
r
e
s
s
(
p
s
f
)
Normal Stress (psf)
Peak
Peak
Ultimate
Ultimate
ANAHEIM TEST LAB, INC
196 Technology Drive, Unit D
Irvine, CA 92618 Phone (949)336-6544 DATE: 09/27/2021 Advanced Geotechnical Solutions, Inc. 485 Corporate Ave., Suite B P.O. NO.: Chain of Custody Escondido, CA 92029 LAB NO.: C-5264 SPECIFICATION: CTM-643/417/422 MATERIAL: Soil
Project No.: 2107-12
Project: HG Fenton Ponto Drive Date Sampled: 09/20/2021
Sample ID: B-1 @ 7-12’ ANALYTICAL REPORT
CORROSION SERIES
SUMMARY OF DATA
pH MIN. RESISTIVITY SOLUBLE SULFATES SOLUBLE CHLORIDES per CT. 643 per CT. 417 per CT. 422
ohm-cm ppm ppm
8.3 1,640 148 321
RESPECTFULLY SUBMITTED
________________________________ WES BRIDGER, LAB MANAGER
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIX D
PRELIMINARY INFILTRATION FEASIBILITY STUDY
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
485 Corporate Drive, Suite B
Escondido, California 92029
P: (619) 867-0487 | E: info@adv-geosolutions.com
ORANGE AND L.A. COUNTIES INLAND EMPIRE SAN DIEGO AND IMPERIAL COUNTIES
(714) 786-5661 (619) 867-0487 (619) 867-0487
H.G. Fenton Company March 16, 2022
7577 Mission Valley Road P/W 2107-12
San Diego, California 92108 Report No. 2107-12-B-5
Attention: Ryley Webb
Subject: Preliminary Infiltration Feasibility Study, Proposed Multi-Family Residential
Development, 7200-7294 Ponto Drive, Carlsbad, California
References: See Attached
Gentleperson:
In accordance with your request, Advanced Geotechnical Solutions, Inc. (AGS) has prepared this
infiltration feasibility study for the proposed multi-family residential development located on 7200-7294
Ponto Drive in the City of Carlsbad, California. This report is intended to meet the preliminary infiltration
testing requirements of the City of Carlsbad. AGS has evaluated the feasibility for storm water infiltration
in accordance with the City of Carlsbad BMP Design Manual (2021). Supporting data are presented in
Appendix AA.
1.0 SITE DESCRIPTION AND PROPOSED DEVELOPMENT
The approximately 4.64 acre site is located north of Ponto Avenue in Carlsbad, California as shown in
Figure 1, Site Location Map. The site encompasses three parcels which are located northeast of the
intersection of Ponto Drive and Ponto Road: APN 214-160-25-00 (1.52 acres), 214-171-11-00 (2.24 acres),
and 214-160-28 (0.92 acres). The parcel north of Ponto Avenue and east of Ponto Drive is currently
occupied by a self-storage facility, which was constructed between 1967 and 1978. The site to the north has
been periodically used as a storage/junk yard and more recently as a contractor lay-down yard, and no
permanent structures are present on the property. The site just to the east is mostly undeveloped aside from
two vacant structures which were constructed between 1967 and 1978.
The site slopes and drains to the south. Based on our review of historical aerial imagery circa 1947, a north-
south trending drainage was located on the self-storage site and contractor site prior to development. This
was filled in and moved by 1953. The channel continued to the south roughly along the current alignment
of Ponto Drive and was filled in and/or moved by 1964. As shown on the Base Map prepared by Hunsaker
and Associates San Diego, site elevations range between 48 feet above mean sea level (msl) on the
southeastern corner to 38 ft. msl on the southwestern corner. A high-pressure gas line with a 10-foot
easement crosses the site from north to south.
According to the Design Study plan prepared by Hunsaker & Associates San Diego, Inc. (2022), it is our
understanding that the project consists of twenty-three two- and three-story multi-family buildings with
parking in the first level, and associated driveways, parking and open space areas. Additional improvements
include sound walls, retaining walls and utility installations. Cuts and fills up to 5 feet in depth are
anticipated.
March 16, 2022 Page 2
P/W 2107-12 Report No. 2107-12-B-5
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
2.0 FIELD INVESTIGATION
On January 31, 2022, five percolation test borings (labeled P-1 through P-5) were advanced to depths
ranging between 5 and 6 feet below ground surface using a mini excavator equipped with an 8-inch diameter
flight auger. Approximate percolation test locations are shown on Plate 1, Exploration Location Plan. An
engineer from our firm logged the percolation test borings for soil and geologic conditions. Boring logs are
presented in Appendix B.
3.0 GEOLOGY
Based upon our subsurface exploration, the site is generally mantled by artificial fill and/or alluvium
underlain by Old Paralic Deposits, Unit 6.
4.0 TEST PROCEDURE
Borehole percolation tests were performed to evaluate the feasibility of storm water infiltration in general
conformance with Appendix D of the City of Carlsbad BMP Design Manual (2021). After drilling, the test
holes were cleaned of sediment and the bottom was lined with approximately 2 inches of washed gravel.
The test holes were then successively filled with clean, potable water and allowed to pre-soak.
After the pre-soak period, the borehole percolation tests were performed by filling the test holes with clean
potable water. Water was allowed to infiltrate during 30-minute periods and the water drop was measured
to calculate the percolation rate in inches per hour. The test hole was then refilled with water as necessary
and the test procedure was repeated over the course of several hours until a stabilized percolation rate was
recorded The stabilized percolation rate was then converted to an infiltration rate based on the “Porchet
Method” utilizing the following equation:
Where:
Logs of field testing and graphical representations of test data presented as infiltration versus time interval
are included in Appendix AA.
5.0 TEST RESULTS AND PRELIMINARY DESIGN VALUES
In accordance with Appendix D, Section D.2.3 of the BMP Design Manual, a safety factor between 2.0 and
9.0 must be applied to the infiltration rates. Details of the BMP improvements are not currently known;
therefore determination of a safety factor should be deferred until the locations, elevations, and type of
BMP improvements are known. If an underdrain system is utilized, a default safety factor of 2.0 may be
applied per Section D.2.3. For purposes of this feasibility study, we have assumed an underdrain system
will be utilized if infiltration type BMP’s are used, and a safety factor of 2 has been used. The percolation
test observations and results are summarized in Table 1.
March 16, 2022 Page 3
P/W 2107-12 Report No. 2107-12-B-5
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
TABLE 1
SUMMARY OF INFILTRATION TEST RESULTS
Test
No.
Depth of
Test
Hole (ft)
Approximate
Test Elevation
(ft, msl)
Geologic
Unit
Soil Classification
(USCS)
Infiltration
Rate*
(in/hr)
Safety
Factor
Design
Infiltration
Rate (in/hr)
P-1 5.1 35 Qop Clay (CH) 0.0 2 0.0
P-2 5.3 35 Qop Clayey Sand (SC) 0.1 2 0.05
P-3 5.7 41 Qop Silty Sand (SM) 0.88 2 0.44
P-4 5.7 41 Qop Silty Sand (SM) 0.38 2 0.19
P-5 5.0 41 Afu/Qop Silty Sand (SM) 1.1 2 0.55
Note: *Calculated by Porchet Method.
6.0 DESIGN CONSIDERATIONS
6.1. Groundwater
Groundwater was encountered at a depth of 20.5 feet bgs in boring B-2. Based on these
observations, the groundwater level was at approximate El. 19.5 feet msl during our subsurface
exploration. According to our review, no natural groundwater condition is known to exist at the
site that would impact the proposed development. It should be noted that localized perched
groundwater may develop at a later date, most likely at or near fill/bedrock contacts, due to
fluctuations in precipitation, irrigation practices, or factors not evident at the time of our field
exploration. According to the BMP Design Handbook, in areas where infiltration BMPs are
planned, a minimum separation of 10 feet between the infiltration surface and the historic high
groundwater should be maintained.
6.2. Soil Characteristics and Anticipated Flow Paths
Based on our subsurface exploration and infiltration testing performed at the site, Old Paralic
Deposits have design rates that vary from 0.0 to 0.44 inches per hour. The lower rates were obtained
where a clay layer was encountered. A higher rate was observed in P-5, where the testing was
completed within both the undocumented fill, which likely has higher infiltration rates, and the
upper native Old Paralic Deposits. The Old Paralic Deposits underlying the project site are
interbedded with fine- and coarse-grained layers and appear to be laterally discontinuous. Some of
the coarser grained layers in the Old Paralic Deposits were encountered at the testing depths in P-
3, P-4, and P-5 and have much higher rates than the finer grained layers encountered in P-1 and P-
2. The finer grained layers consist of stiff silty clay and dense to very dense clayey sand and sandy
silt. These layers possess very low to negligible infiltration rates and will act as an aquitard
impeding vertical movement of water. As such, infiltrating water will flow vertically within the
coarser-grained layers until fine-grained, less permeable materials are encountered. The infiltrating
water will then flow laterally upon the less permeable materials. Due to the interbedded and
discontinuous nature of the Old Paralic Deposits that underlie the site, the ultimate flow paths are
March 16, 2022 Page 4
P/W 2107-12 Report No. 2107-12-B-5
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
difficult to predict; however, there is a high likelihood that infiltrating water will flow laterally and
may negatively impact existing offsite improvements, including roadways and utilities, that cannot
be reasonably mitigated.
6.3. Geotechnical Hazards
Stormwater infiltration improvements will be located in close proximity to proposed structures and
underground utilities. There is a high likelihood for water intrusion to occur in subjacent utility
trenches and artificial fill which could create saturated soil conditions beneath structures and other
settlement sensitive improvements. There is also a possibility that the infiltrating water can flow
laterally and impact existing offsite improvements, including nearby roadways, utility trenches,
residences, and the adjacent parking garage to the north. This potential geotechnical hazard could
be mitigated by designing the BMP improvements for no infiltration and lining the improvements
with an impermeable membrane.
6.4. Soil Contamination
During our recent site investigation, no evidence of soil contamination was observed, nor is any
contamination known to exist onsite. Utilizing the DWR online resource Geotracker.ca.gov, no
open cases were identified within 1000 feet of the subject site.
6.5. Proximity to Water Supply Wells
No wells were observed onsite. No wells have been mapped in close proximity to the site.
6.6. Maintenance of Infiltration Device
Regular maintenance of any infiltration system is critical to the long term successful operation of
the system. Responsibilities of maintaining the system are typically borne by the owner. Improperly
maintained infiltration devices and basins have a high failure rate. A plan should be developed by
the designer of the system and implemented throughout the project’s lifetime.
7.0 CONCLUSIONS AND RECOMMENDATIONS
Infiltration testing in the upper soils yielded highly variable preliminary design infiltration rates ranging
between 0.0 to 0.55 inches per hour. Due to the presence of less permeable layers within the Old Paralic
Deposits, infiltrating water may flow vertically until encountering a less permeable layer, where the water
may then flow laterally. Determining the ultimate flow paths would be very difficult.
Infiltration at the potential BMP locations will increase the potential for geotechnical issues such as water
intrusion and ground settlement. Mitigation typically includes an appropriate setback between nearby
improvements and infiltration devices. An alternative mitigation can include construction of a cutoff wall,
such as placement of a vertical impermeable liner or slurry filled trench, to mitigate infiltration of water
below adjacent improvements. To prevent the migration of water along utility pipe bedding zones, slurry
backfill should be considered in utility pipes located near infiltration devices. However, these mitigation
measured may not feasible for existing offsite improvements. It should be recognized that if infiltration is
allowed, some water intrusion is likely to occur beneath nearby existing improvements such as roadways
and nearby structures. Accordingly, it is not recommended that infiltration type BMP improvements be
March 16, 2022 Page 5
P/W 2107-12 Report No. 2107-12-B-5
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
installed. Water intrusion should be prevented by installing an impermeable liner on all underground BMP
improvements.
The infiltration rates presented in this report are based on limited testing performed as part of a preliminary
screening for feasibility purposes. Dependent upon the final location, depth, and type of proposed BMP,
additional testing may be warranted.
Advanced Geotechnical Solutions, Inc. appreciates the opportunity to provide you with geotechnical
consulting services and professional opinions. If you have any questions, please contact the undersigned at
(619) 867-0487.
Respectfully Submitted,
Advanced Geotechnical Solutions, Inc.Reviewed by:
___________________________ _____________________________
JOHN J. DONOVAN PAUL J. DERISI
RCE 65051/GE 2790, Reg. Exp. 6-30-23 CEG 2536, Reg. Exp. 5-31-23
Distribution: (1) Addressee
Attachments: References
Appendix AA - Borehole Percolation Field Data
Appendix B - Boring Logs
Figure 1 - Site Location Map
Plate 1 - Exploration Location Plan
March 16, 2022 Page 6
P/W 2107-12 Report No. 2107-12-B-5
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
REFERENCES
Advanced Geotechnical Solutions, Inc., 2021, “Due Diligence Geotechnical Study, Proposed Multi-Family
Residential Development, 7200-7590 Ponto Drive, Carlsbad County of Orange, California,” dated
December 3, 2021 (Report No. 2107-12-B-2R).
City of Carlsbad, 2021, Storm Water Standard – BMP Design Manual, February 2016, Revised
September 1, 2021, Edition.
State of California Water Boards, May 16, 2019, http://geotracker.waterboards.ca.gov/
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIX AA
BOREHOLE PERCOLATION FIELD DATA
PERCOLATION TEST DATA SHEET
Project: Ponto Dr. Project No.: 2107‐12 Date: 2/2/2022
P‐1 Tested By: SD Water Temp.: 65
62 inches USCS: CH Air Temp.: 64
Test Hole Dimensions (Inches)
Length: 62 Diameter: 8
Infiltration Test
Trial No. Start Time Stop Time Time Interval Average Perc Rate Infiltration Rate*
(hr and min) (hr and min) (min.) Start Depth End Depth Depth Change Water Column (in./hr.) (in./hr.)
1 11:01 11:31 30 28 28 0 28.00 0.00 0.00
2 11:31 12:01 30 28 28 0 28.00 0.00 0.00
3 12:01 12:31 30 28 28 0 28.00 0.00 0.00
4 12:31 12:55 24 28 28 0 28.00 0.00 0.00
5 12:55 13:30 35 28 28 0 28.00 0.00 0.00
6 13:30 14:00 30 28 28 0 28.00 0.00 0.00
7 14:00 14:30 30 28 28 0 28.00 0.00 0.00
8 14:30 15:00 30 28 28 0 28.00 0.00 0.00
9 15:00 15:30 30 28 28 0 28.00 0.00 0.00
*Calculated via Porchet Method
Test Hole No.:
Depth of Test Hole:
Piezometric Surface (inches)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0 30 60 90 120 150 180 210 240 270 300 330 360
In
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Time Elapsed (min)
PERCOLATION TEST DATA SHEET
Project: Ponto Dr. Project No.: 2107‐12 Date: 2/2/2022
P‐2 Tested By: SD Water Temp.: 65
64 inches USCS: SC Air Temp.: 64
Test Hole Dimensions (Inches)
Length: 64 Diameter: 8
Infiltration Test
Trial No. Start Time Stop Time Time Interval Average Perc Rate Infiltration Rate*
(hr and min) (hr and min) (min.) Start Depth End Depth Depth Change Water Column (in./hr.) (in./hr.)
1 11:03 11:33 30 23 10/16 22 9/16 1 1/16 23.09 2.13 0.17
2 11:35 12:03 28 22 15/16 22 15/16 22.47 2.01 0.16
3 12:03 12:33 30 22 21 6/16 10/16 21.69 1.25 0.11
4 12:34 12:55 21 21 14/16 21 4/16 10/16 21.56 1.79 0.15
5 12:56 13:32 36 21 14/16 20 13/16 1 1/16 21.34 1.77 0.15
6 13:34 14:02 28 21 12/16 20 14/16 14/16 21.31 1.88 0.16
7 14:02 14:32 30 20 14/16 20 1/16 13/16 20.47 1.63 0.14
8 14:32 15:02 30 20 12/16 20 4/16 8/16 20.50 1.00 0.09
9 15:02 15:32 30 20 15/16 20 5/16 10/16 20.63 1.25 0.11
10 15:32 16:02 30 20 15/16 20 7/16 8/16 20.69 1.00 0.09
*Calculated via Porchet Method
Test Hole No.:
Depth of Test Hole:
Piezometric Surface (inches)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0 30 60 90 120 150 180 210 240 270 300 330 360
In
f
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(i
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Time Elapsed (min)
PERCOLATION TEST DATA SHEET
Project: Ponto Dr. Project No.: 2107‐12 Date: 2/2/2022
P‐3 Tested By: SD Water Temp.: 65
68 inches USCS: SM Air Temp.: 64
Test Hole Dimensions (Inches)
Length: 68 Diameter: 9
Infiltration Test
Trial No. Start Time Stop Time Time Interval Average Perc Rate Infiltration Rate*
(hr and min) (hr and min) (min.) Start Depth End Depth Depth Change Water Column (in./hr.) (in./hr.)
1 10:10 11:06 56 26 11 4/16 14 12/16 18.63 15.80 1.70
2 11:08 11:38 30 24 12/16 17 12/16 7 21.25 14.00 1.34
3 11:40 12:07 27 27 8/16 20 14/16 6 10/16 24.19 14.72 1.25
4 12:08 12:37 29 28 2/16 20 10/16 7 8/16 24.38 15.52 1.31
5 12:39 13:09 30 28 15/16 21 7 15/16 24.97 15.88 1.31
6 13:11 13:38 27 29 10/16 22 8/16 7 2/16 26.06 15.83 1.26
7 13:40 14:07 27 28 22 2/16 5 14/16 25.06 13.06 1.08
8 14:09 14:36 27 28 2/16 22 8/16 5 10/16 25.31 12.50 1.02
9 14:38 15:07 29 27 8/16 22 4/16 5 4/16 24.88 10.86 0.90
10 15:08 15:38 30 27 10/16 22 8/16 5 2/16 25.06 10.25 0.84
11 15:39 16:12 33 28 7/16 22 8/16 5 15/16 25.47 10.80 0.88
*Calculated via Porchet Method
Test Hole No.:
Depth of Test Hole:
Piezometric Surface (inches)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0 30 60 90 120 150 180 210 240 270 300 330 360
In
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Time Elapsed (min)
PERCOLATION TEST DATA SHEET
Project: Ponto Dr. Project No.: 2107‐12 Date: 2/2/2022
P‐4 Tested By: SD Water Temp.: 65
68 inches USCS: SM Air Temp.: 64
Test Hole Dimensions (Inches)
Length: 68 Diameter: 9
Infiltration Test
Trial No. Start Time Stop Time Time Interval Average Perc Rate Infiltration Rate*
(hr and min) (hr and min) (min.) Start Depth End Depth Depth Change Water Column (in./hr.) (in./hr.)
1 10:04 11:09 65 28 16 12 22.00 11.08 1.03
2 11:11 11:41 30 26 4/16 23 2/16 3 2/16 24.69 6.25 0.52
3 11:43 12:10 27 26 10/16 24 6/16 2 4/16 25.50 5.00 0.41
4 12:12 12:40 28 26 10/16 24 8/16 2 2/16 25.56 4.55 0.37
5 12:42 13:14 32 26 14/16 23 15/16 2 15/16 25.41 5.51 0.45
6 13:15 13:41 26 26 13/16 24 9/16 2 4/16 25.69 5.19 0.42
7 13:43 14:11 28 26 8/16 24 2/16 2 6/16 25.31 5.09 0.42
8 14:13 14:39 26 27 9/16 25 8/16 2 1/16 26.53 4.76 0.37
9 14:41 15:09 28 29 26 3 27.50 6.43 0.49
10 15:11 15:42 31 28 15/16 26 5/16 2 10/16 27.63 5.08 0.38
11 15:42 16:13 31 28 13/16 26 3/16 2 10/16 27.50 5.08 0.384
*Calculated via Porchet Method
Test Hole No.:
Depth of Test Hole:
Piezometric Surface (inches)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0 30 60 90 120 150 180 210 240 270 300 330 360
In
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Time Elapsed (min)
PERCOLATION TEST DATA SHEET
Project: Ponto Dr. Project No.: 2107‐12 Date: 2/2/2022
P‐5 Tested By: SD Water Temp.: 65
68 inches USCS: SM Air Temp.: 64
Test Hole Dimensions (Inches)
Length: 68 Diameter: 9
Infiltration Test
Trial No. Start Time Stop Time Time Interval Average Perc Rate Infiltration Rate*
(hr and min) (hr and min) (min.) Start Depth End Depth Depth Change Water Column (in./hr.) (in./hr.)
1 10:51 11:14 23 33 15 18 24.00 46.96 4.02
2 11:15 11:46 31 28 13 4/16 14 12/16 20.63 28.55 2.81
3 11:49 12:15 26 31 17 6/16 13 10/16 24.19 31.44 2.68
4 12:17 12:45 28 28 8/16 15 10/16 12 14/16 22.06 27.59 2.55
5 12:46 13:20 34 31 15/16 20 11 15/16 25.97 21.07 1.68
6 13:20 13:50 30 20 13 8/16 6 8/16 16.75 13.00 1.54
7 13:51 14:15 24 23 8/16 18 5 8/16 20.75 13.75 1.35
8 14:16 14:45 29 34 25 4/16 8 12/16 29.63 18.10 1.28
9 14:45 15:14 29 25 4/16 19 6 4/16 22.13 12.93 1.19
10 15:16 15:48 32 28 10/16 21 7 10/16 24.81 14.30 1.19
11 15:50 16:17 27 29 12/16 23 8/16 6 4/16 26.63 13.89 1.082
*Calculated via Porchet Method
Test Hole No.:
Depth of Test Hole:
Piezometric Surface (inches)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0 30 60 90 120 150 180 210 240 270 300 330 360
In
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ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIX E
EARTHWORK SPECIFICATIONS
General Earthwork Specifications Page 1
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
GENERAL EARTHWORK SPECIFICATIONS
I. General
A. General procedures and requirements for earthwork and grading are presented herein. The earthwork and
grading recommendations provided in the geotechnical report are considered part of these specifications, and
where the general specifications provided herein conflict with those provided in the geotechnical report, the
recommendations in the geotechnical report shall govern. Recommendations provided herein and in the
geotechnical report may need to be modified depending on the conditions encountered during grading.
B. The contractor is responsible for the satisfactory completion of all earthwork in accordance with the project
plans, specifications, applicable building codes, and local governing agency requirements. Where these
requirements conflict, the stricter requirements shall govern.
C. It is the contractor’s responsibility to read and understand the guidelines presented herein and in the
geotechnical report as well as the project plans and specifications. Information presented in the geotechnical
report is subject to verification during grading. The information presented on the exploration logs depicts
conditions at the particular time of excavation and at the location of the excavation. Subsurface conditions
present at other locations may differ, and the passage of time may result in different subsurface conditions being
encountered at the locations of the exploratory excavations. The contractor shall perform an independent
investigation and evaluate the nature of the surface and subsurface conditions to be encountered and the
procedures and equipment to be used in performing his work.
D. The contractor shall have the responsibility to provide adequate equipment and procedures to accomplish the
earthwork in accordance with applicable requirements. When the quality of work is less than that required, the
Geotechnical Consultant may reject the work and may recommend that the operations be suspended until the
conditions are corrected.
E. Prior to the start of grading, a qualified Geotechnical Consultant should be employed to observe grading
procedures and provide testing of the fills for conformance with the project specifications, approved grading
plan, and guidelines presented herein. All remedial removals, clean-outs, removal bottoms, keyways, and
subdrain installations should be observed and documented by the Geotechnical Consultant prior to placing fill.
It is the contractor’s responsibility to apprise the Geotechnical Consultant of their schedules and notify the
Geotechnical Consultant when those areas are ready for observation.
F. The contractor is responsible for providing a safe environment for the Geotechnical Consultant to observe
grading and conduct tests.
II. Site Preparation
A. Clearing and Grubbing: Excessive vegetation and other deleterious material shall be sufficiently removed as
required by the Geotechnical Consultant, and such materials shall be properly disposed of offsite in a method
acceptable to the owner and governing agencies. Where applicable, the contractor may obtain permission from
the Geotechnical Consultant, owner, and governing agencies to dispose of vegetation and other deleterious
materials in designated areas onsite.
B. Unsuitable Soils Removals: Earth materials that are deemed unsuitable for the support of fill shall be removed
as necessary to the satisfaction of the Geotechnical Consultant.
C. Any underground structures such as cesspools, cisterns, mining shafts, tunnels, septic tanks, wells, pipelines,
other utilities, or other structures located within the limits of grading shall be removed and/or abandoned in
accordance with the requirements of the governing agency and to the satisfaction of the Geotechnical Consultant.
General Earthwork Specifications Page 2
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
D. Preparation of Areas to Receive Fill: After removals are completed, the exposed surfaces shall be scarified to
a depth of approximately 8 inches, watered or dried, as needed, to achieve a generally uniform moisture content
that is at or near optimum moisture content. The scarified materials shall then be compacted to the project
requirements and tested as specified.
E. All areas receiving fill shall be observed and approved by the Geotechnical Consultant prior to the placement
of fill. A licensed surveyor shall provide survey control for determining elevations of processed areas and
keyways.
III. Placement of Fill
A. Suitability of fill materials: Any materials, derived onsite or imported, may be utilized as fill provided that
the materials have been determined to be suitable by the Geotechnical Consultant. Such materials shall be
essentially free of organic matter and other deleterious materials, and be of a gradation, expansion potential,
and/or strength that is acceptable to the Geotechnical Consultant. Fill materials shall be tested in a laboratory
approved by the Geotechnical Consultant, and import materials shall be tested and approved prior to being
imported.
B. Generally, different fill materials shall be thoroughly mixed to provide a relatively uniform blend of materials
and prevent abrupt changes in material type. Fill materials derived from benching should be dispersed throughout
the fill area instead of placing the materials within only an equipment-width from the cut/fill contact.
C. Oversize Materials: Rocks greater than 8 inches in largest dimension shall be disposed of offsite or be placed
in accordance with the recommendations by the Geotechnical Consultant in the areas that are designated as
suitable for oversize rock placement. Rocks that are smaller than 8 inches in largest dimension may be utilized
in the fill provided that they are not nested and are their quantity and distribution are acceptable to the
Geotechnical Consultant.
D. The fill materials shall be placed in thin, horizontal layers such that, when compacted, shall not exceed 6
inches. Each layer shall be spread evenly and shall be thoroughly mixed to obtain near uniform moisture content
and uniform blend of materials.
E. Moisture Content: Fill materials shall be placed at or above the optimum moisture content or as recommended
by the geotechnical report. Where the moisture content of the engineered fill is less than recommended, water
shall be added, and the fill materials shall be blended so that near uniform moisture content is achieved. If the
moisture content is above the limits specified by the Geotechnical Consultant, the fill materials shall be aerated
by discing, blading, or other methods until the moisture content is acceptable.
F. Each layer of fill shall be compacted to the project standards in accordance to the project specifications and
recommendations of the Geotechnical Consultant. Unless otherwise specified by the Geotechnical Consultant,
the fill shall be compacted to a minimum of 90 percent of the maximum dry density as determined by ASTM
Test Method: D1557-09.
G. Benching: Where placing fill on a slope exceeding a ratio of 5 to 1 (horizontal to vertical), the ground should
be keyed or benched. The keyways and benches shall extend through all unsuitable materials into suitable
materials such as firm materials or sound bedrock or as recommended by the Geotechnical Consultant. The
minimum keyway width shall be 15 feet and extend into suitable materials, or as recommended by the
geotechnical report and approved by the Geotechnical Consultant. The minimum keyway width for fill over cut
slopes is also 15 feet, or as recommended by the geotechnical report and approved by the Geotechnical
Consultant. As a general rule, unless otherwise recommended by the Geotechnical Consultant, the minimum
width of the keyway shall be equal to 1/2 the height of the fill slope.
General Earthwork Specifications Page 3
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
H. Slope Face: The specified minimum relative compaction shall be maintained out to the finish face of fill and
stabilization fill slopes. Generally, this may be achieved by overbuilding the slope and cutting back to the
compacted core. The actual amount of overbuilding may vary as field conditions dictate. Alternately, this may
be achieved by back rolling the slope face with suitable equipment or other methods that produce the designated
result. Loose soil should not be allowed to build up on the slope face. If present, loose soils shall be trimmed to
expose the compacted slope face.
I. Slope Ratio: Unless otherwise approved by the Geotechnical Consultant and governing agencies, permanent
fill slopes shall be designed and constructed no steeper than 2 to 1 (horizontal to vertical).
J. Natural Ground and Cut Areas: Design grades that are in natural ground or in cuts should be evaluated by the
Geotechnical Consultant to determine whether scarification and processing of the ground and/or overexcavation
is needed.
K. Fill materials shall not be placed, spread, or compacted during unfavorable weather conditions. When grading
is interrupted by rain, filing operations shall not resume until the Geotechnical Consultant approves the moisture
and density of the previously placed compacted fill.
IV. Cut Slopes
A. The Geotechnical Consultant shall inspect all cut slopes, including fill over cut slopes, and shall be notified
by the contractor when cut slopes are started.
B. If adverse or potentially adverse conditions are encountered during grading; the Geotechnical Consultant shall
investigate, evaluate, and make recommendations to mitigate the adverse conditions.
C. Unless otherwise stated in the geotechnical report, cut slopes shall not be excavated higher or steeper than the
requirements of the local governing agencies. Short-term stability of the cut slopes and other excavations is the
contractor's responsibility.
V. Drainage
A. Back drains and Subdrains: Back drains and subdrains shall be provided in fill as recommended by the
Geotechnical Consultant and shall be constructed in accordance with the governing agency and/or
recommendations of the Geotechnical Consultant. The location of subdrains, especially outlets, shall be surveyed
and recorded by the Civil Engineer.
B. Top-of-slope Drainage: Positive drainage shall be established away from the top of slope. Site drainage shall
not be permitted to flow over the tops of slopes.
C. Drainage terraces shall be constructed in compliance with the governing agency requirements and/or in
accordance with the recommendations of the Geotechnical Consultant.
D. Non-erodible interceptor swales shall be placed at the top of cut slopes that face the same direction as the
prevailing drainage.
VI. Erosion Control
A. All finish cut and fill slopes shall be protected from erosion and/or planted in accordance with the project
specifications and/or landscape architect's recommendations. Such measures to protect the slope face shall be
undertaken as soon as practical after completion of grading.
B. During construction, the contractor shall maintain proper drainage and prevent the ponding of water. The
contractor shall take remedial measures to prevent the erosion of graded areas until permanent drainage and
erosion control measures have been installed.
General Earthwork Specifications Page 4
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
VII. Trench Excavation and Backfill
A. Safety: The contractor shall follow all OSHA requirements for safety of trench excavations. Knowing and
following these requirements is the contractor's responsibility. All trench excavations or open cuts in excess of
5 feet in depth shall be shored or laid back. Trench excavations and open cuts exposing adverse geologic
conditions may require further evaluation by the Geotechnical Consultant. If a contractor fails to provide safe
access for compaction testing, backfill not tested due to safety concerns may be subject to removal.
B. Bedding: Bedding materials shall be non-expansive and have a Sand Equivalent greater than 30. Where
permitted by the Geotechnical Consultant, the bedding materials can be densified by jetting.
C. Backfill: Jetting of backfill materials is generally not acceptable. Where permitted by the Geotechnical
Consultant, the bedding materials can be densified by jetting provided the backfill materials are granular, free-
draining and have a Sand Equivalent greater than 30.
VIII. Geotechnical Observation and Testing During Grading
A. Compaction Testing: Fill shall be tested by the Geotechnical Consultant for evaluation of general compliance
with the recommended compaction and moisture conditions. The tests shall be taken in the compacted soils
beneath the surface if the surficial materials are disturbed. The contractor shall assist the Geotechnical Consultant
by excavating suitable test pits for testing of compacted fill.
B. Where tests indicate that the density of a layer of fill is less than required, or the moisture content not within
specifications, the Geotechnical Consultant shall notify the contractor of the unsatisfactory conditions of the fill.
The portions of the fill that are not within specifications shall be reworked until the required density and/or
moisture content has been attained. No additional fill shall be placed until the last lift of fill is tested and found
to meet the project specifications and approved by the Geotechnical Consultant.
C. If, in the opinion of the Geotechnical Consultant, unsatisfactory conditions, such as adverse weather,
excessive rock or deleterious materials being placed in the fill, insufficient equipment, excessive rate of fill
placement, results in a quality of work that is unacceptable, the consultant shall notify the contractor, and the
contractor shall rectify the conditions, and if necessary, stop work until conditions are satisfactory.
D. Frequency of Compaction Testing: The location and frequency of tests shall be at the Geotechnical
Consultant's discretion. Generally, compaction tests shall be taken at intervals not exceeding two feet in fill
height and 1,000 cubic yards of fill materials placed.
E. Compaction Test Locations: The Geotechnical Consultant shall document the approximate elevation and
horizontal coordinates of the compaction test locations. The contractor shall coordinate with the surveyor to
assure that sufficient grade stakes are established so that the Geotechnical Consultant can determine the test
locations. Alternately, the test locations can be surveyed and the results provided to the Geotechnical Consultant.
F. Areas of fill that have not been observed or tested by the Geotechnical Consultant may have to be removed
and recompacted at the contractor's expense. The depth and extent of removals will be determined by the
Geotechnical Consultant.
G. Observation and testing by the Geotechnical Consultant shall be conducted during grading in order for the
Geotechnical Consultant to state that, in his opinion, grading has been completed in accordance with the
approved geotechnical report and project specifications.
H. Reporting of Test Results: After completion of grading operations, the Geotechnical Consultant shall submit
reports documenting their observations during construction and test results. These reports may be subject to
review by the local governing agencies.
Project:
P/W 2107-12
Report:Date:
Mar. 2022
Exploration Location Plan
PLATE 1
2107-12-B-4
AGS LEGEND:
Approximate location of hollow stem
auger borings ( , 2021)AGS
B-3
afu Artificial Fill - Undocumented
AlluviumQal
Approximate location of percolation
( , 2022)AGS
P-2
TP-6
Approximate location of test pit
( , 2022)AGS
Old Paralic DepositsQop
TP-1
B-2
B-1
P-1
B-3
B-3
0.0 - 4.0 ft.
4.0 - 16.5 ft.
afu
Qop
T.D. 16.5 ft.
No Water
B-4
B-4
0.0 - 4.0 ft.
4.0 - 20.8 ft.
afu
Qop
T.D. 20.8 ft.
No Water
B-5
B-5
0.0 - 6.0 ft.
6.0 - 16.5 ft.
afu
Qop
T.D. 16.5 ft.
No Water
B-6
B-6
0.0 - 2.5 ft.afu
Refusal @ 2.5 ft.
No Water
B-7
B-7
0.0 - 2.5 ft.
2.5 - 5 ft.
afu
Qop
T.D. 5 ft.
No Water
P-2 P-2
0.0 - 4.0 ft.
4.0 - 5.5 ft.
T.D. 5.5 ft.
No Water
afu?
Qop
P-3P-3
0.0 - 1.0 ft.
1.0 - 5.0 ft.
T.D. 5.0 ft.
No Water
Topsoil
Qop
P-4P-4
0.0 - 2.0 ft.
2.0 - 5.5 ft.
T.D. 5.5 ft.
No Water
afu/Qal
Qop
P-5P-5
0.0 - 4.0 ft.
4.0 - 5.5 ft.
T.D. 5.5 ft.
No Water
afu
Qop?
TP-1
0.0 - 3.5 ft.
3.5 - 8.0 ft.
T.D. 8.0 ft.
No Water
afu/Qal
Qop
TP-2
0.0 - 1.5 ft.
1.5 - 6.0 ft.
T.D. 6.0 ft.
No Water
Qal
Qop
TP-3
0.0 - 1.5 ft.
1.5 - 4.0 ft.
4.0 - 6.0 ft.
T.D. 6.0 ft.
No Water
afu
Qal
Qop
TP-4
0.0 - 9.0 ft.
9.0 - 13.5 ft.
T.D. 13.5 ft.
No Water
afu
Qop
TP-6
0.0 - 3.0 ft.
3.0 - 6.0 ft.
T.D. 6.0 ft.
No Water
afu
Qop
TP-7
0.0 - 3.5 ft.
3.5 - 7.0 ft.
T.D. 7.0 ft.
No Water
Qal
Qop
TP-10
0.0 - 5.0 ft.
5.0 - 5.5 ft.
T.D. 5.5 ft.
No Water
afu
Qop
TP-5
0.0 - 2.5 ft.
2.5 - 5.0 ft.
5.0 - 12.5 ft.
T.D. 12.5 ft.
No Water
afu
Qal
Qop
TP-8
0.0 - 2.5 ft.
2.5 - 5.0 ft.
5.0 - 12.5 ft.
T.D. 12.5 ft.
No Water
afu
Qal
QopTP-9
0.0 - 0.5 ft.
0.5 - 3.5 ft.
3.5 - 4 ft.
T.D. 4 ft.
No Water
afu
Qal
Qop
TP-2
TP-3
TP-4
TP-8
TP-5
TP-7
TP-9
TP-10
TP-6
P-1
0.0 - 3.0 ft.
3.0 - 5.0 ft.
T.D. 5.0 ft.
No Water
afu
Qop
B-2
0.0 - 4.0 ft.
4.0 - 21.5 ft.
afu
Qop
T.D. 21.5 ft.
Water at 20.5 ft.
B-1
0.0 - 26.5 ft.
T.D. 26.5 ft.
No Water
Qop