HomeMy WebLinkAboutCDP 2020-0019; SLATTERY MS - TRITON STREET; Geotechnical Investigation and Infiltration Study; 2018-08-278AGS ADVANCED GEOTECHNICAL SOLUTIONS, INC.
485 Corporate Drive, Suite B
Escondido, California 92029
Telephone: (619) 867-0487 Fax: (714) 409-3287
ZAJDAGROUP
Oceanside, CA
Attention: Ms. Sarah Zajda
August 27, 2018
P/W 1802-02
Report No. 1802-02-B-2
Subject Geotechnical Investigation and Infiltration Study, Proposed 2-Lot Development,
Triton Street, Carlsbad, California
Gentlepersons:
Presented herein is Advanced Geotechnical Solutions, Inc.'s, (AGS's) geotechnical investigation and
infiltration study for the proposed 2-lot residential development at Triton Street (APN 215-070-23) in the
City of Carlsbad, California.
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.
Prepared by:
~~ *Q
RCE 62366/GE 2715, Reg. Exp. 9-30-19
Reviewed by:
Distribution: (I) Addressee (electronic copy)
ORANGE AND L.A. COUNTIES
(714) 786-5661
INLAND EMPIRE
(619) 867-0487
SAN DIEGO AND IMPERIAL COUNTIES
( 619) 867-0487
August 27, 2018
P/W 1802-02
TABLE OF CONTENTS
Page ii
Report No. 1802-02-B-2
Page
1.0 INTRODUCTION .............................................................................................................. 1
I .I. Scope of Study ................................................................................................................ 1
1.2. Geotechnical Study Limitations ...................................................................................... 2
2.0 SITE LOCATION AND PROPOSED DEVELOPMENT ................................................. 2
3.0 CURRENT INVESTIGATION .......................................................................................... 2
4.0 ENGINEERING GEOLOGY ............................................................................................. 3
4.1. Regional Geologic and Geomorphic Setting .................................................................. 3
4.2. Site Geology .................................................................................................................... 3
4.3. Stratigraphy ..................................................................................................................... 3
4.3.1. Artificial Fill -Undocumented (Map Symbol afu) ................................................. 3
4.3.2. Very Old Paralic Deposits, Units 10-11 (Map Symbol Qvopl0-11) ...................... 3
4.4. Groundwater ................................................................................................................... 3
4.5. Non-Seismic Hazards ...................................................................................................... 4
4.5.1. Mass Wasting .......................................................................................................... 4
4.5.2. Flooding .................................................................................................................. 4
4.5.3. Subsidence and Ground Fissuring .......................................................................... 4
4.6. Faulting ........................................................................................................................... 4
4.7. Seismic Hazards .............................................................................................................. 4
4.7.1. Surface Fault Rupture ............................................................................................. 4
4.7.2. Seismicity ................................................................................................................ 5
4.7.3. Seismic Design Parameters ..................................................................................... 5
4. 7.4. Liquefaction ............................................................................................................ 5
4.7.5. Dynamic Settlement ................................................................................................ 6
4.7.6. Landsliding ............................................................................................................. 6
4. 7. 7. Earthquake Induced Flooding ................................................................................. 6
5.0 GEOTECHNICAL ENGINEERING .................................................................................. 6
5 .1. Excavation Characteristics .............................................................................................. 6
5.2. Compressibility ............................................................................................................... 6
5 .3. Collapse Potential/Hydro-Consolidation ........................................................................ 6
5.4. Expansion Potential ........................................................................................................ 6
5 .5. Analytical Methods ......................................................................................................... 7
5 .5 .1. Bearing Capacity ..................................................................................................... 7
5.5.2. Lateral Earth Pressures ........................................................................................... 7
5.6. Pavement Support Characteristics .................................................................................. 7
6.0 CONCLUSIONS AND RECOMMENDATIONS ............................................................. 7
6.1. Earthwork ........................................................................................................................ 7
6.1.1. Site Preparation ....................................................................................................... 7
6.1.2. Removals ................................................................................................................. 8
6.1.3. Overexcavation ....................................................................................................... 8
6.1.4. Materials for Fill ..................................................................................................... 8
6.1.5. Import Soils ............................................................................................................. 8
6.1.6. Compacted Fill ........................................................................................................ 8
6.1.7. Mixing and Moisture Control ................................................................................. 9
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6.1.8. Utility Trench Backfill ............................................................................................ 9
6.1.9. Flatwork Subgrade Preparation ............................................................................... 9
6.2. Excavations and Shoring ................................................................................................. 9
6.3. Foundation Design Recommendations ......................................................................... 10
6.3.1. Footing Excavations .............................................................................................. 10
6.3.2. Isolated Footings ................................................................................................... 11
6.3.3. Moisture and Vapor Barrier .................................................................................. 11
6.3.4. Lateral Earth Pressures ......................................................................................... 11
6.3.5. Seismic Earth Pressure .......................................................................................... 11
6.3.6. Backfill and Drainage of Walls ............................................................................. 12
6.4. Exterior Flatwork .......................................................................................................... 12
6.5. Preliminary Pavement Design ....................................................................................... 12
6.6. Site Drainage ................................................................................................................. 13
6.7. Corrosion ....................................................................................................................... 13
6.8. Concrete Mix Design .................................................................................................... 13
6.9. Buried Metallic Materials ............................................................................................. 13
7.0 FUTURE STUDY NEEDS ............................................................................................... 14
7.1. Plan Review .................................................................................................................. 14
7.2. Observation during Construction .................................................................................. 14
8.0 CLOSURE ........................................................................................................................ 14
ATTACHMENTS:
Figure 1 -Site Location Map
Figure 2 -Site Exploration Map
Figure 3 -Regional Geologic Map
Appendix A -References
Appendix B -Boring Logs
Appendix C -Laboratory Test Results
Appendix D -Preliminary Infiltration Feasibility Study
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
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1.0
GEOTECHNICAL INVESTIGATION AND INFILTRATION STUDY
PROPOSED 2-LOT DEVELOPMENT
TRITON STREET, CARLSBAD, CALIFORNIA
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 2-lot residential development at Triton Street (APN 215-070-23) 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 four manually excavated soil borings (Appendix B).
► Geotechnical laboratory testing on selected soil samples (Appendix C).
► Perform two borehole percolation tests to evaluate the feasibility of storm water infiltration in
accordance with 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 2016 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 the 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.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
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1.2.
2.0
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.
SITE LOCATION AND PROPOSED DEVELOPMENT
The rectangular-shaped site is located south of Triton Street, east of an unpaved access driveway, west and
north of two lots with residences, equestrian facilities and undeveloped areas in Carlsbad, California as
shown in Figure 1. The site consists of two contiguous parcels totaling roughly 0.67 acres which are
currently vacant and are covered by grass and isolated small trees. The parcels were previously used for
agricultural purposes.
The site is mostly flat with drainage flowing by sheet flow towards the southwest comer. A more defined
drainage swale is located along the southeastern comer of the site. Total relief across the site ranges from
Elevation 340 feet above mean sea level (msl) on the northeast comer to Elevation 335 feet msl on the
southwest comer.
Based on the tentative parcel map (Figure 2), the project will consist of two residences with approximate
footprint areas of 3,600 square feet each. We anticipate that the residences will have one to two stories and
that appurtenant driveways, stormwater basins associated with site BMP's, new utility installation and tie-
ins will be necessary to develop the site. Minor cuts and fills on the order of one to two feet are anticipated.
3.0 CURRENT INVESTIGATION
On July 13, 2018, AGS conducted subsurface exploration at the subject site. Four (4) exploratory borings
(HA-1 through HA-4) were manually excavated to depths ranging from 1 to 4.5 feet below ground surface
(bgs). The approximate boring locations are shown on Figure 2, Site Exploration Map. Upon completion
of excavating, the borings were backfilled with soil cuttings. The materials encountered in the borings were
logged by our field personnel. The boring logs are presented in Appendix B.
Bulk samples of the soils were obtained from the borings at various depths in an effort to evaluate lithologic
changes and onsite geology at the study site. Soil samples were transported to AGS's laboratory and tested
for expansion index, remolded shear strength, maximum density and optimum moisture content, and
resistivity/corrosion potential. Laboratory results are presented in Appendix C.
In addition, two (2) borehole percolation tests (P-1 and P-2) 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, Appendix D, Section D.3.3.2 guidelines. The results of the
infiltration study are presented in Appendix D. Additional infiltration testing is recommended once detailed
stormwater management plans are developed for the site.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
SITE LOCATION MAP
2-LOT DEVELOPMENT,
TRITON STREET, CARLSBAD, CALIFORNIA
SOURCE MAP-GOOGLE MAPS
P/W 1802-02 FIGURE 1
~~GS ADVANCED GEOTECHNICAL SOLUTIONS, INC.
485 Corporate Drive, Suite B
Escondido, CA 92029
Telephone: (619) 867-0487 Fax: (714) 409-3287
CITY OF CARLSBAD TEN TA 77V£ PARCEL MAP
LEGEND
HA◄ .
P-2 .
afu
I
'1..; .... ..._ , __ ~· :
Approximate location of exploratory boring
Approximate location of infiltration test
Artificial fill -undocumented
Qvop, .. 11 Very Old Paralic Deposits, units 10-11
--
I
:t ,-----('.E:'
\
afu
-s~:,{iu':A(Qvop i
10-11)
I
I
I
-?-Approximate location of geologic contact (queried where uncertain)
t
SNCCr, fT , .sNlET
-----·---·,.,--------·-------·--·---·---·-----·----
----=-s
~
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Report No. 1802-02-B-2
4.0 ENGINEERING GEOLOGY
4.1. Regional Geologic and Geomorphic Setting
4.2.
4.3.
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.
Site Geology
Current published regional geologic maps indicate the site is underlain by middle to early
Pleistocene-age Very Old Paralic Deposits (Kennedy, M.P., and Tan, S.S., 2005) as shown in
Figure 3, Regional Geologic Map. According to our observations, the site is locally mantled by
artificial fill underlain by Very Old Paralic Deposits. The following is a brief description of the
geologic units encountered.
Stratigraphy
Based on our observations, the site is underlain by shallow deposits of artificial fill on the southeast
corner of the site and Very Old Paralic Deposits in the majority of the site. The approximate
distribution of the geologic units is shown on the enclosed Figure 2. The following is a brief
description of the geologic units observed, listed from youngest to oldest.
4.3.1. Artificial Fill -Undocumented (Map Symbol afu)
Artificial fill materials were encountered in Boring HA-4 extending to an approximate
depth of 2 inches. Fill materials are likely locally derived and was observed consist of
reddish brown, damp, loose, fine-grained silty sand. Fill depth across the site is anticipated
to range between one and two feet. Documentation regarding fill placement was not
available for our review.
4.3.2. Very Old Paralic Deposits, Units 10-11 (Map Symbol Qvopl0-11)
Middle to early Pleistocene-age very old paralic deposits mantle the site and underlie
artificial fill. This unit consisted of reddish, grayish and yellowish brown, damp to moist,
dense to very dense, weakly to moderately cemented (carbonate), intensely to moderately
weathered, silty sandstone. This unit may include zones of hard, strongly cemented
sandstone. Iron oxide staining was observed throughout.
4.4. Groundwater
Groundwater was not encountered during our subsurface investigation. No natural groundwater
condition is known to exist at the site that would impact the proposed development. It should be
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
REGIONAL GEOLOGIC MAP
2-LOT DEVELOPMENT,
TRITON STREET, CARLSBAD, CALIFORNIA
0VOP10-11 I Very old paralic deposits, undivided (middle to early Pleistoncece)
P/W 1802-02 FIGURE 3
SOURCE MAP -GEOLOGIC MAP OF THE OCEANSIDE
30'X60' QUADRANGLE, CALIFORNIA. KENNEDY &
TAN 2007. ~~GS ADVANCED GEOTECHNICAL SOLUTIONS, INC.
485 Corporate Drive, Suite B
Escondido, CA 92029
Telephone: (619) 867-0487 Fax: (714) 409-3287
August 27, 2018
P/W 1802-02
Page 4
Report No. 1802-02-B-2
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 explorations.
4.5. Non-Seismic Hazards
4.5.1. Mass Wasting
No evidence of mass wasting was observed onsite nor was any noted on the reviewed maps.
4.5.2. Flooding
According to FEMA flood mapping, the site is within Area X corresponding to areas of
minimal flood hazard.
4.5.3. 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.
4.6. Faulting
The closest known active fault to the site is the Rose Canyon/Newport-Inglewood Fault system,
located approximately 5.2 miles west of the site. No faults have been mapped within the site or in
the site vicinity. Review of vintage aerial photographs did not show strong or moderately developed
lineaments.
4.7. 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.
4.7.1. 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
observation of the site and review of available geologic maps, there is no known faulting
at the subject site. The nearest known active fault is the Rose Canyon/Newport-Inglewood
Fault system which is approximately 5.2 miles west of the site. Accordingly, the potential
for fault surface rupture within the project is very low.
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4.7.2. 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 California Building Code (2016) requirements and those of the controlling
local agency.
4.7.3. Seismic Design Parameters
After implementation of the grading recommendations provided in this report, the site may
be classified as Seismic Site Class C consisting of a very dense soil and soft rock profile
with average SPT N blowcount above 50 blows per foot. Table 4.7.3 present seismic design
parameters in accordance with the 2016 CBC and mapped spectral acceleration parameters
(United States Geological Survey, 2018). Site coordinates of Latitude 33.1125°N and
Longitude 117.2898°W were utilized.
TABLE 4.7.3
2016 CBC SEISMIC DESIGN PARAMETERS -SITE CLASS D
Mapped Spectral Acceleration Parameter at Period of0.2-Second, Ss 1.093g
Mapped Spectral Acceleration Parameter at Period I-Second, S1 0.42 Ig -
Site Coefficient, Fa 1.000
Site Coefficient, Fv 1.379
Adjusted MCER1 Spectral Response Acceleration Parameter at Short Period, SMs 1.093g
I-Second Period Adjusted MCER1 Spectral Response Acceleration Parameter, SMI 0.58Ig
Short Period Design Spectral Response Acceleration Parameter, SDS 0.729g
I-Second Period Design Spectral Response Acceleration Parameter, SDI 0.387g
Peak Ground Acceleration, PGAM2 0.430g
Seismic Design Category D
Notes: 1 Risk-Targeted Maximum Considered Earthquake
2 Peak Ground Acceleration adjusted for site effects
4. 7.4. Liquefaction
Liquefaction is the phenomenon where seismic agitation ofloose, 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
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. Based on
the subsurface data collected by AGS, the absence of shallow groundwater, and the
remedial grading recommendations provided in this report, the liquefaction potential after
development is considered very low.
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5.0
4.7.5. 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 negligible.
4.7.6. 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. Review of aerial photos and topographic maps, as well as field observations during
geologic mapping and subsurface exploration activities, indicates no evidence of deep-
seated landsliding within the project limits.
4.7.7. Earthquake Induced Flooding
Earthquake induced flooding can be caused by seiches, or tsunamis. A seiche is a free or
standing-wave oscillation on the surface of water in an enclosed or semi enclosed basin.
Considering the elevation and distance of the site from the coastline, the potential for
flooding due to tsunamis is non-existent.
GEOTECHNICAL ENGINEERING
Presented herein is a general discussion of the geotechnical properties of the various soil types and the
analytic methods used in this report.
5.1. Excavation Characteristics
5.2.
It is anticipated that excavations within artificial fill and very old paralic deposits can be
accomplished with conventional grading equipment (D-9 or equivalent).
Compressibility
Onsite materials that are significantly compressible in their current condition include artificial fill,
and the upper highly weathered portion of very old paralic deposits. These materials will require
complete removal prior to placement of fill, where exposed at design grade and possibly where
exposed in cut slopes.
5.3. Collapse Potential/Hydro-Consolidation
5.4.
Given the dense nature of the formational materials and the removals proposed herein, the potential
for hydro-consolidation is considered to be negligible.
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
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of the onsite materials will vary from "Very Low" to "Low". Mitigation measures for expansive
soils are provided in the recommendations section of this report.
5.5. Analytical Methods
5.5.1. Bearing Capacity
Ultimate bearing capacity and shoring design values were obtained using the graphs and
formulas presented in NA VFAC DM-7.1. Allowable bearing was determined by applying
a factor of safety of at least three to the ultimate bearing capacity.
5.5.2. 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.
5.6. Pavement Support Characteristics
6.0
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 of30 can be utilized
for the preliminary design of pavements. Final design should be based upon representative
sampling of the as-graded soils.
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
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.
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6.1.2. Removals
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Undocumented fill material and the upper highly weathered portion of very old paralic
deposits are not considered suitable for structural support in their present condition and
should be removed prior to placement of compacted engineered fill. Removals extending
to depths of 1 to 2 feet are anticipated onsite.
The majority of the excavated soils may be reused for engineered fills provided they are
clean of debris and organic content. The extent and depth of removals should be evaluated
by the soil engineer or engineering geologist in the field based on the materials exposed.
6.1.3. Overexcavation
The proposed structures should be supported entirely on compacted fill or Very 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 I-foot below footings, whichever
is deeper. The limits of this overexcavation should extend 5 feet outside the building limits.
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.
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. T he
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.
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6.2.
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 optimum moisture content prior to concrete
placement.
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. For vertical
excavations less than approximately 15 feet in height, cantilevered shoring may be used. For design
of cantilevered shoring, a triangular distribution of lateral earth pressure based on an equivalent
fluid pressure of 35 pcf is recommended. It is assumed that the backfill soils are drained and that a
level surface exists behind the cantilevered shoring.
Any surcharge (live, including traffic, or dead load) located within a 1: 1 plane drawn upward and
outward from the base of the shored excavation, including adjacent structures, should be added to
the lateral earth pressures. The lateral contribution of a uniform surcharge load located immediately
behind the temporary shoring can be estimated as approximately 35% and 50% of the magnitude
of the vertical surcharge pressure for the "active" and "at-rest" conditions, respectively. As a
minimum, a 300 psf vertical uniform surcharge is recommended to account for neighboring
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
August 27, 2018
P/W 1802-02
Page 10
Report No. 1802-02-B-2
6.3.
structures and/or traffic loads. Additional lateral load contributions from surcharges located behind
the shored wall may be provided once the load configuration and layout are known.
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.
Foundation Design Recommendations
Detailed foundation plans are not currently available; however, it is our understanding that the
proposed one-to two-story residential structures will be supported by a conventional shallow
foundation system. For design of shallow foundations supported on competent Very Old Paralic
Deposits or compacted fill, the values presented in Table 6.3 should be used.
TABLE6.3
FOUNDATION DESIGN PARAMETERS
Minimum Footing • Width: 12 inches for one-story and 15 inches for two-story
Dimensions1 • Depth: 12 inches
• Foundations should be supported on either compacted fill or
competent Very Old Paralic Deposits.
Allowable Bearing • For footings with recommended minimum dimensions
Capacity allowable bearing capacity is 2,000 pounds per square foot (pst)
• Allowable bearing values may be increased by one-third for
transient live loads from wind or seismic forces.
• Total settlement: 1.0 inch
Estimated Static • Differential settlement: 0.5 inch over 40 feet.
Settlement • Static settlement of the foundation system is expected to occur on
initial application of loading.
Allowable Coefficient of 0.40 Friction Below Footings
Lateral Bearing2 300 psf/foot of depth to a maximum of 2,000 psf
(Level Condition)
Notes: I. Depth of footing embedment should be measured below lowest adjacent finish grade.
2. 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.
6.3.1. 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
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.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
August 27, 2018
P/W 1802-02
6.3.2. Isolated Footings
Page 11
Report No. 1802-02-B-2
Isolated footings outside the structure footprint should be tied with grade beams to the
structure in two orthogonal directions.
6.3.3. 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 retarder should be of
suitable composition, thickness, strength and low permeance to effectively prevent the
migration of water and reduce the transmission of water vapor to acceptable levels.
Historically, a 10-mil plastic membrane, such as Visqueen, placed between one to four
inches of clean sand, has been used for this purpose. More recently, 15-mil polyolefin
membrane underlayments (Stego® Wrap or similar material) have been used. The use of
this system or other systems, materials or techniques can be considered, at the discretion
of the designer.
6.3.4. Lateral Earth Pressures
For the design ofretaining walls that are not restrained against movement by rigid corners
or structural connections, an active pressure represented by an equivalent fluid weight of
35 pcf may be assumed. Restrained walls (non-yielding) may be designed for an at-rest
pressure represented by an equivalent fluid weight of 55 pcf. This pressure assumes low-
expansive, level backfill and free draining conditions. Retaining walls should also be
designed for any surcharge loading located within a 1: 1 plane drawn upward and outward
from the base of the wall, including adjacent structures as described in Section 6.2. The
recommended design lateral earth pressures were calculated assuming that a drainage
system will be installed behind the retaining walls and that external hydrostatic pressure
will not develop behind the walls.
6.3.5. 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 2016 CBC.
The seismic load can be modeled as a thrust load applied at a point 0.6H above the base of
the wall, where His equal to the height of the wall. The seismic load (in pounds per lineal
foot of wall) may be calculated as follows:
where:
Pe = ¾ *y*H2 *kh
Pe = Seismic thrust load
H = Height of the wall (feet)
y = soil unit weight= 125 pounds per cubic foot (pct)
kh = seismic pseudostatic coefficient = 0.5 * PGAM
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
August 27, 2018
P/W 1802-02
6.3.6. Backfill and Drainage of Walls
Page 12
Report No. 1802-02-B-2
The backfill material behind walls should consist of granular non-expansive material and
should be approved by the project geotechnical engineer. Based on our observations, the
soil materials encountered during our exploration meet this requirement. Retaining walls
should be waterproofed and adequately drained in order to limit hydrostatic buildup behind
walls. Wall drainage may be provided by a geosynthetic drainage composite such as
TerraDrain®, MiraDrain®, or equivalent, attached to the outside perimeter of the wall. 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 of¾-inch crushed rock wrapped in suitable non-woven filter fabric
(Mirafi® 140NL or equivalent). The 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.
6.4. 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.
6.5. Preliminary Pavement Design
For preliminary design and estimating purposes, the following pavement structural section is
provided based on a traffic index (TI) of 5 and an assumed "R"-Value of 30.
TABLE6.5
PRELIMINARY PAVEMENT SECTION
Traffic Index Asphaltic Concrete (AC) Class II Aggregate Base (AB)
(TI) (inches) (inches)
5.0 3 4
If Portland cement concrete (PCC) pavement is preferred, the pavement structural section should
consist of 5-inch thick PCC with a flexural strength of 600 psi placed over compacted subgrade
soils.
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.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
August 27, 2018
P/W 1802-02
Page 13
Report No. 1802-02-B-2
6.6. 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.
6.7. Corrosion
6.8.
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 of7,200 ohm-cm, soil
pH value of 6.8, chloride content of22 parts per million (ppm) and sulfate content of 0.013 percent
(i.e., 127 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 for detailed recommendations.
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 a sulfate content of 0.013 percent
for the tested sample, which corresponds to sulfate exposure Class SO -Negligible (sulfate content
below 0.1%) per ACI 318 (2011). 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.
6.9. Buried Metallic Materials
The onsite soils are expected to be mildly 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.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
August 27, 2018
P/W 1802-02
Page 14
Report No. 1802-02-B-2
7.0 FUTURE STUDY NEEDS
7.1. Plan Review
7.2.
8.0
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.
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.
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
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
August 27, 2018
P/W 1802-02
REFERENCES
Page A-1
Report No. 1802-02-B-2
Advanced Geotechnical Solutions Inc., 2018, "Proposal and Cost Estimate for Geotechnical Investigation
and Infiltration Study, Proposed 2-Lot Development, Triton Street, Carlsbad, California", dated
July 6, 2018, Report No. 1801-02.
American Concrete Institute, 2011, Building Code Requirements for Structural Concrete (ACI318M-11)
and Commentary (ACI 318RM-l l), ACI International, Farmington Hills, Michigan.
American Society for Testing and Materials, 2008, Annual Book of ASTM Standards, Section 4,
Construction, Volume 04.08, Soil and Rock (I), ASTM International, West Conshohocken,
Pennsylvania.
California Code of Regulation, Title 24, 2016 California Building Code, 3 Volumes.
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 117 A, 108 p.
California Water Boards, Geotracker web site, depth to groundwater,
http:/ I geotracker. water boards. ca.gov I gamal gamamap/pub 1 ic/ default.asp
City of Carlsbad, 2016, BMP Design Manual, dated February 2016.
County of San Diego Office of Emergency Services, 2010, Draft Liquefaction Map, County of San Diego
Hazard Mitigation Plan, dated August 2010.
FEMA, 2012, Flood Insurance Rate Map, San Diego County, Map Numbers 06073Cl035G, Revised May
16, 2012, Scale: 1"=500'.
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., 2005, 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, August 23, 2018, http://geotracker.waterboards.ca.gov/
United States Geologic Survey (USGS), 2018, U.S. Seismic Design Maps web tool,
http://www.earthguake.usgs.gov/designmaps/us/application.php
Weber, F. N., 1971, Mines and mineral resources of San Diego County, California: California Division of
Mines and Geology, County Report 3.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIXB
BORING LOGS
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
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BORING NUMBER HA-1
PAGE 1 OF 1
ADVANCED GEORCHNICAI. SOUITIONS, INC.
CLIENT Zajda Grau[) PROJECT NAME Triton Street
PROJECT NUMBER 1802-02 PROJECT LOCATION Carlsbad California
DATE STARTED 7/10/18 COMPLETED 7/10/18 GROUND ELEVATION 338.8 ft HOLE SIZE 19
DRILLING CONTRACTOR AGS GROUND WATER LEVELS:
DRILLING METHOD Hand Auger AT TIME OF DRILLING --
LOGGED BY ss CHECKED BY SD AT END OF DRILLING --
NOTES AFTER DRILLING --
~ ATTERBERG 1--w g w~ 0 Cl) LIMITS z a.. 1--w
I () i'.: ffi (/) [u a::~ z Cl) i'.: 1--
1--~ :i:0 Cl) s1--:::i t:::'n ::ii--0 w z
a.. ¢: a..o () MATERIAL DESCRIPTION wo:i 0Z__! 1--Z ~ 1--gl--() QG:J o;g w~ ~_J
Cl) _J~ _J :::i:;; z a. (/)w <t: a:: ~t::: ()~ :::i a..:::i o:iO :::i~ -1--a:: w :::i-(/)~ t--o 0 oz a~ Cl) ('.) ~z ()~ & ~o :::i I ::J _J ::5 ::J Cl)z w <t: 1--1--::s-Cl) 0 () <t: 0 a.. z
0 Cl) a.. u:::
SM Ve!Y Old Paralic DeE!osits, {QvoE!10-11):
SIL TY SANDSTONE, fine grained, red brown to gray ,____ >--brown, damp to moist, dense; highly weathered, weakly
cemented, minor porosity
>--@ 2.0 in., Become red brown to yellow brown, slightly
moist, very dense; weathered, moderately cemented, iron
-oxide staining
-BU ~ M ,
REM.
___1__ HEAl1
-
Total depth = 1 .5 ft
No groundwater
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8AGS BORING NUMBER HA-2
PAGE 1 OF 1
ADVANCED Gf.Ol£CIINICAL SOLlJTIONS, INC.
CLIENT Zajda Grour:1 PROJECT NAME Triton Street
PROJECT NUMBER 1802-02 PROJECT LOCATION Carlsbad California
DATE STARTED 7/10/18 COMPLETED 7/10/18 GROUND ELEVATION 336.5 ft HOLE SIZE 12
DRILLING CONTRACTOR AGS GROUND WATER LEVELS:
DRILLING METHOD Hand Auger AT TIME OF DRILLING --
LOGGED BY ss CHECKED BY SD AT END OF DRILLING --
NOTES AFTER DRILLING -
~ ATTERBERG I-~ w g ~ 0 Cl) LIMITS z c.. w~ I-w () ~ffi Cl) w a:::~ z Cl) ~ I-I :i:0 Cl) 3;:1-::i !:::'fi" ::i I-0 w z I-~ () wa:i 0z...1 1-Z i= I-Q1-
() ~~ 0~ c.. ¢:' c..o Cl) MATERIAL DESCRIPTION ...J~ ...J ::i <( z a. ww <( a::: i= !::: ()~ w~ c?_...J ::i c..::, a:io> ::i~ -I-a::: w ::,-Cl)~ 1-0 0 (.'.) ~z 06 ~ Oz ::i I a~ ::i ::J Wz Cl)
<( ~o I-I-::3...J ::j-w
Cl) 0 () ~ 0 c.. z
0 c.. u::
SM Ve!Y Old Paralic De12osits, {Qvo1210-11):
SIL TY SANDSTONE, fine grained, red brown to gray -brown, damp to moist, dense; highly weathered, weakly
cemented, minor porosity
-
-
-@ 0.5 ft., Becomes red brown to yellow brown, damp, very
dense; weathered, moderately cemented, iron oxide
staining -
__.1_
-
-
-
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8AGS BORING NUMBER HA-3
PAGE 1 OF 1
ADVANCED GEOTECHNICAL SOLl/TIONS, INC.
CLIENT Zajda Groui:1 PROJECT NAME Triton Street
PROJECT NUMBER 1802-02 PROJECT LOCATION Carlsbad California
DATE STARTED 7/10/18 COMPLETED 7/10/18 GROUND ELEVATION 336.5 ft HOLE SIZE 12
DRILLING CONTRACTOR AGS GROUND WATER LEVELS:
DRILLING METHOD Hand Auger AT TIME OF DRILLING --
LOGGED BY SS CHECKED BY SD AT END OF DRILLING --
NOTES AFTER DRILLING -
~ ATTERBERG I-w g w~ e.... Cl) LIMITS z (L I-w u ~ffi (/) w a::~ z Cl) ~ I-I :i:G Cl) :s:1-::i t:: c;::-::JI-0 w z I-~ u wa::i oz__J 1-Z i= I-Q1-u 0~ (L = o...o MATERIAL DESCRIPTION zu i= t:: ~?;5 w~ ~__J Cl) __J~ __J ::J:; ::J -3, (/)w <( 0:: ::i-ue.... ::J (L ::J mO -1-0:: w (/)~ 1-o 0 Oz a~ Cl) ('.) ~z u~ >-~o ::J I ::i __J :::i ::i (/)z w <( 0:: I-I-:::s-Cl) 0 u <( 0 (L z
0 Cl) (L u:::
SM Ve!Y Old Paralic De~osits, {Qvo~10-11):
SIL TY SANDSTONE, fine grained, red brown to gray
brown, damp, dense; highly weathered, weakly cemented,
minor porosity
-@ 2.0 in., Becomes red brown to yellow brown, damp, very
dense; weathered, moderately cemented, iron oxide
-staining
-
1
Total depth = 1.0 ft
No groundwater
Backfilled with soil cuttings
'1JAGS BORING NUMBER HA-4
ADVANCED GEOTECHNlffll. SOLUTIONS. INC.
CLIENT Zajda Groui:1 PROJECT NAME Triton Street
PROJECT NUMBER 1802-02 PROJECT LOCATION Carlsbad California
f-
C: (.') .f-0 a§
~ "'
DATE STARTED 7/10/18 COMPLETED 7/10/18 GROUND ELEVATION 337.5 ft
DRILLING CONTRACTOR AGS GROUND WATER LEVELS:
DRILLING METHOD Hand Auger AT TIME OF DRILLING --
LOGGED BY ss CHECKED BY SD AT END OF DRILLING -
NOTES AFTER DRILLING --
LU ~ a.. en Cu (.) ~ffi :r: :i: <.'.l Cf) s I-:::i !:: 'fi' I-~ (.) LU(!) 0Z_J a.. ¢:: a..o MATERIAL DESCRIPTION z 0. Cf) _J~ _J :::i <( LU~ ri_J :::i a..:::i a:io> :::i~ 0 ('.) ~z 06 ~ <(
Cf) 0
0
~ SM Artificial Fill -Undocumented, {afu):
\ SIL TY SAND, fine grained, medium brown to red brown, I -damp, loose to medium dense SM Ve!)l Old Paralic De[!osits, {Qvo[!10-11): -SIL TY SANDSTONE, fine grained, red brown to yellow
brown, damp, very dense; weathered, moderately
-cemented, iron oxide staining
-
c3
ti ~
z 0 t-o: >--~ ~
en t--&l 0 "' a. ;::: z ~ -' t--z w a, en ~ w ::. :::,
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HOLE SIZE
~ ~ ~ 0 Cf)
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:::i I-0 LU
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PAGE 1 OF 1
12
ATTERBERG I-
LIMITS z LU
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91--(.) a~ i== !:: -x (.) s. ~LU :::i-Cf)~ a~ t--o Cf) :'.5:::; Wz :::; _J 5-LU a.. z a.. u:::
APPENDIXC
LABORATORY TEST RESULTS
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
August 27, 2018
P/W 1802-02
Classification
APPENDIXC
LABORATORY TESTING
Page C-1
Report No. 1802-02-B-2
Soils were visually and texturally classified in accordance with the Unified Soil Classification System
(USCS) in general accordance with ASTM D2488. Soil classifications are indicated on the boring logs
in Appendix B.
Expansion Index
The expansion index of selected materials was evaluated in general accordance with ASTM D4829.
Specimens were molded under a specified compactive energy at approximately 50 percent saturation
(±1 percent). The prepared I-inch thick by 4-inch diameter specimens were loaded with a surcharge of
144 pounds per square foot and were inundated with tap water. Readings of volumetric swell were
made for a period of 24 hours. The results of these tests are presented on Figure C-1.
Modified Proctor Density
The maximum dry density and optimum moisture content of a selected representative soil sample was
evaluated using the Modified Proctor method in general accordance with ASTM D1557. The results
of these tests are summarized on Figure C-2.
Direct Shear
Direct shear tests were performed on remolded samples in general accordance with ASTM D3080 to
evaluate the shear strength characteristics of selected materials. The samples were inundated during
shearing to represent adverse field conditions. The results are shown on Figure C-3.
Soil Corrosivity
A soil pH, and resistivity test were performed on a representative sample in general accordance with
California Test (CT)643. The chloride content of a selected sample was evaluated in general
accordance with CT422. The sulfate content of a selected sample was evaluated in general accordance
with CT417. The test results are presented on Figure C-4.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
EXPANSION INDEX -ASTM D4829
Project Name: Triton Street --------
Location: Carisbad --------
Project No.: 1802-02 --------
Date: 07-2018
Excavation: HA-1
Depth (ft): 0.16 -1.5
Description: Silty Sand
Tested by: HM
Checked by: AB
Expansion Index -ASTM D4829
Initial Dry Density (pct): 114.6
Initial Moisture Content(%): 8.5
Initial Saturation (%): 48.8
Final Dry Density (pct): 113.3
Final Moisture Content(%): 17.7
Final Saturation (%): 98.0
Expansion Index: 12
Expansion Potential: Very Low
ASTM D4829 -Table 5.3
Expansion Expansion
Index Potential
0-20 Very Low
21 -50 Low
51 -90 Medium
91 -130 High
>130 Very High
EI_HA-1_ 0.16-1.5ft_ 1802-02_AB
Figure C-1
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
MAXIMUM DENSITY -ASTM D1557
Project Name: Triton Street Excavation: HA 1
Location: Carlsbad Depth (ft): 0.16 -1.5
Project No.: 1802-02 Description: Siltl Sand
Date: 7/26/2018 Tested By: HM
Method A
Test Number 1 2 3 4
Dry Density (pcf) 124.4 127.2 127.0 125.1
Moisture Content (%) 8.5 9.8 11.0 12.2
MAXIMUM DENSITY CURVE
c-0 C. -130
~ "' C: Cl)
C
~
C 125
20
Moisture (%)
Maximum Density 127.5 pcf Optimum Moisture __ 1_0_.2 __ %
Figure C-2
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
DIRECT SHEAR -ASTM D3080
Project Name: Triton Street Excavation: B-1 ----Location: Carisbad --------Depth: 0.16 -1.5
Project No.: 1802-02 Tested by: HM
2500
2000
~ Q.
";;;-1500 ~ t;;
:U 1000 ..,
..c "' 500
0
--------Date: 7/28/2018
Samples Tested 1
lntial Moisture (%) 6.4
Initial Dry Density (pct) 98.6
Normal Stress (psf) 1000
Peak Shear Stress (psf) 822
Ult. Shear Stress (psf) 763
2 3
6.4 6.4
96.7 99.0
2000 3000
1497 2202
1468 2173
Reviewed by: AB
Soil Type: Silty Sand
Test: Remolded
Method: Drained
Consolidation: Yes
Saturation: Yes
Shear Rate (in/min): 0.005
Strength Parameters Peak Ultimate
2500
2000
;;:--! 1500
"' "' CII ... iii ... RI 1:; 1000
VI
500
0
0 500
Friction Angle, phi (deg) 35 35
Cohesion (osf) 100 50
o Peak
-Peak
D Ultimate
---Ultimate
1500 2000 2500 3000 3500 4000
Normal Stress (psf)
Shear Stress v. Displacement Vertical Deformation v. Displacement
0.05
[I
0.00 0.10
.................
I ················· 3000
-----2000
0.20 0.30
Displacement (in)
;[ 0.04
2; 0.03
:.:; "' E .E ~
iii
0.02
0.01
~ 0.00 .., '•·-......................... .
> -0.01
-0.02
0.00
........................................................ 3000
1-----2000
0.10 0.20 0.30
Displacement (in)
Figure C-3
Advanced Geotechnical Solutions, Inc.
485 Corporate Ave., Suite B
Escondido, CA 92029
J.N.: 1802-02
Project: Triton Street
Carlsbad
Date sampled: 07 /11 / 18
Location: On Site
HA-2@ 6"-3'
pH
6.8
ANAHEIM TEST LAB, INC
3008 ORANGE AVENUE
SANT A ANA, CALIFORNIA 92707
PHONE (714) 549-7267
ANALYTICAL REPORT
CORROSION SERIES
SUMMARY OF DATA
SOLUBLE SULFATES
per CT. 417
ppm
127
SOLUBLE CHLORIDES
per CT. 422
ppm
22
DATE: 08/07 /18
P.O. NO.: Chain of Custody
LAB NO.: C-2107
SPECIFICATION: CT-417 /422/643
MATERIAL: Soil
MIN. RESISTIVITY
per CT. 643
ohm-cm
7,200
RESPECTFULLY SUBMITTED
WES BRIDGER CHEMIST
Figure C-4
APPENDIXD
PRELIMINARY INFILTRATION FEASIBILITY STUDY
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
ZAJDAGROUP
Oceanside, CA
Attention: Ms. Sarah Zajda
ADVANCED GEOTECHNlrAL SOLUTIONS, INC.
485 Corporate Drive, Suite B
Escondido, CA 92029
Telephone: (619) 867-0487
August 27, 2018
P/W 1802-02
Report No. 1802-02-B-3
Subject Preliminary Infiltration Feasibility Study, Proposed 2-Lot Development, Triton
Street, Carlsbad, California
References: See Appendix A
Gentlemen:
In accordance with your request, Advanced Geotechnical Solutions, Inc. (AGS) has prepared this
preliminary infiltration feasibility study for the proposed 2-lot development located on Triton Street in the
City of Carlsbad, California. The purpose of this report is to evaluate the feasibility of stormwater
infiltration at the subject site. This report is intended to meet City of Carlsbad infiltration testing
requirements and evaluate feasibility of stormwater infiltration in accordance with the current City of
Carlsbad BMP Design Manual. A discussion of our field testing and findings are presented below.
Worksheet Form I-8 and associated supporting data are presented in Appendix A1•
1.0 SITE DESCRIPTION AND PROPOSED DEVELOPMENT
The rectangular shaped property (APN 215-070-23) is located on the south side of Triton Street at its
westerly terminus (Figure l, Site Location Map). It is surrounded by a dirt road on the westerly side,
single family residential lots on the southerly and easterly sides, and Triton Street on the northerly side.
The site slopes gently to the northwest corner. Total relief across the site ranges from Elevation 340 feet
above mean sea level (ms!) on the northeast corner to Elevation 335 feet msl on the southwest corner. The
site is currently vacant. Based on a review of historical aerial imagery, the site was previously used as a
nursery.
Based on the provided tentative parcel map, it is proposed to subdivide the property into two lots, and
construct single-family residential structures on each. Although grading plans have not been developed,
minor cuts and fills are anticipated.
2.0 FIELD INVESTIGATION
To evaluate the feasibility of storm water infiltration on the site and provide preliminary design
infiltration rates, two (2) borehole percolation tests (P-1 and P-2) were performed in general conformance
with Appendix D, Section D.3.3.2 of the current City of Carlsbad BMP Design Manual. Additionally,
four ( 4) exploratory borings were excavated onsite as a part of AGS's subsurface exploration.
Approximate test locations are shown on Figure 2, Site Exploration Map. The borings were hand
ORANGE AND L.A. COUNTIES
(714) 786-5661
INLAND EMPIRE
(619) 867-0487
SAN DIEGO AND IMPERIAL COUNTIES
( 619) 867-0487
August 27, 2018
P/W 1802-02
Page D-2
Report No. 1802-02-B-3
excavated to depths that range from approximately I to 4.5 feet below ground surface (bgs). Boring HA-
I is located at P-1 and HA-4 at P-2.
A representative from our firm continuously logged the borings for soil and geologic conditions.
Exploratory logs and percolation test results are presented in Appendix A1•
3.0 GEOLOGY
The project site is generally overlain by very old paralic deposits with minor fill soils within the
southeasterly corner of the site. As observed in the borings, the fill consists of brown to red brown, fine
grained silty sand in a damp and loose to medium dense condition. As observed, the very old paralic
deposits consists of red brown to yellow brown, fine-grained, cemented, silty sandstone in a dry to
slightly moist and dense condition. Groundwater was not observed in the borings and is not anticipated to
impact the feasibility of infiltrating stormwater onsite.
4.0 TEST PROCEDURES
The test holes were cleaned of loose debris, lined with approximately 2-inches of washed gravel then
filled with clean, potable water and allowed to pre-soak. Short sections of 6-inch diameter PVC pipe were
installed in the test holes to help mitigate against sloughing/caving of the test hole walls. A series of
falling head infiltration tests were performed. The test holes were filled with clean, potable water to
approximately 6 to 12 inches above the infiltration surface and allowed to infiltrate. The water level was
allowed to drop for a 30-minute period, the water level was then measured and the drop rate calculated 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:
.1H r 60
It= M( rrr2 + 2rrrHavg) M(r + 2Havg
It = tested infiltration rate, inches/hour
.1H = change in head over time interval, inches
M = time interval, minutes
r = effective radius of test hole
Havg = average head over time interval, inches
Field testing logs and graphical representations of test data in terms of infiltration rate versus time interval
are included in Appendix A1 as supporting documents for Form 1-8.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
August 27,2018
P/W 1802-02
Page D-3
Report No. 1802-02-B-3
5.0 TEST RESULTS AND PRELIMINARY DESIGN VALUES
The results of our testing are summarized in Table 1 below.
TABLE 1
SUMMARY OF INFILTRATION TEST RESULTS
Test Hole Depth of Test Approximate Geologic Description Tested Infiltration
No. Hole Test Elevation Unit Rate <inches/hour)
P-1 24 inches 338.8 ft. ms! Qvop Silty Sandstone 0.347
P-2 54 inches 337.5 ft. ms! Qvop Silty Sandstone 0.130
Table 2 summarizes the preliminary design infiltration rates utilizing a factor of safety of 2.
TABLE2
SUMMARY OF PRELIMINARY DESIGN INFILTRATION RATES
Test Hole Tested Infiltration Rate Factor of Design Infiltration Rate
No. (in./hr.) Safety (in./hr.)
P-1 0.347 2 0.17
P-2 0.130 2 0.07
6.0 DESIGN CONSIDERATIONS
6.1. Groundwater
6.2.
Groundwater was not encountered in our exploratory borings. No natural groundwater condition
is known to exist at the site that would impact the proposed site development. However, 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 explorations.
Geotechnical Hazards
There are no significant geotechnical hazards known to exist on or adjacent to the project site that
cannot be mitigated to an acceptable level.
6.3. Soil Contamination
6.4.
During our recent site investigation, no evidence of soil contamination was observed, nor is any
contamination known to exist onsite. Utilizing the online resource Geotracker.ca.gov, no open
cases were identified within l 000 feet of the subject site.
Soil Characteristics and Anticipated Flow Paths
The soils underlying the project site are identified as the very old paralic deposits, and generally
consisted of red brown to yellow brown, fine grained silty sandstone, in a dry to slightly moist
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
August 27, 2018
P/W 1802-02
Page D-4
Report No. 1802-02-B-3
and dense condition. This unit may include discontinuous pockets of very dense, highly cemented
calcium carbonate. Based on site specific testing and our previous experience in the project area,
the formational soils/bedrock underlying the site are considered to have very low to negligible
permeability when saturated.
6.5. Proximity to Water Supply Wells
There are no known water supply wells within the project vicinity.
7.0 CONCLUSIONS AND RECOMMENDATIONS
Based on the results of our infiltration testing, the onsite very old paralic deposits possess preliminary
design infiltration rates, utilizing a Factor of Safety of 2, ranging between 0.07 to 0.17 inches/hour with
an average of 0.11 inches/hour. These rates indicate a partial infiltration condition. Based on final BMP
types and locations further evaluation of the feasibility of stormwater infiltration may be required.
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.
SHANE P. SMITH
Staff Engineer
~J. DERISI, Vice President
CEG 2536, Reg. Exp. 5-31-19
Distribution: ( l ) Addressee
Attachments: References
Appendix A1-Supporting Data
Reviewed by:
VAN, Vice President
E 2790, Reg. Exp. 6-30-1
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
August 27, 2018
P/W 1802-02
REFERENCES
Page D-5
Report No. 1802-02-B-3
California Building Standards Commission, 2016, California Building Code, Title 24, Part 2, Volumes 1
and 2.
City of Carlsbad, 2016, BMP Design Manual, Effective Date February 16, 2016.
Kennedy, M.P., and Tan, S.S., 2005, Geologic Map of the Oceanside 30' x 60' Quadrangle, California,
California Geological Survey, Preliminary Geologic Maps, Scale 1: 100,000.
Land Surveying Consultants, Inc. (2018), 20-scale, City of Carlsbad Tentative Parcel Map, Sheet 1 of 1,
Dated June 20, 2018.
County of San Diego, 2016, Storm Water Standard-BMP Design Manual, February 2016 Edition.
State of California Water Boards, September 23, 2016, http://geotracker.waterboards.ca.gov/
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIXA1
SUPPORTING DATA
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
Categorization of Infiltration Feasibility Condition Form 1-8
Part 1 -Full Infiltration Feasibility Screening Criteria
Would infiltration of the full design volume be feasible from a physical perspective without any undesirable
consequences that cannot be reasonably mitigated?
Criteria Screening Question
Is the estimated reliable infiltration rate below proposed facility locations
greater than 0.5 inches per hour? The response to this Screening Question
shall be based on a comprehensive evaluation of the factors presented in
Appendix C.2 and Appendix D.
Provide basis:
Yes No
□ ~
Two (2) borehole percolation tests were performed for a general site feasibility for the implementation of
infiltration type BMP's. Testing was performed in general conformance with Appendix D, Section D .3.3.2 of the
current BMP Design Manual. The stabilized percolation rate was conve1ted to an infiltration rate based on the
"Porchet Method." For the purpose offeasibility screening, a factor of safety of2 has been applied to the
infiltration rate. Based on the results of our infiltration testing, the onsite soils possess design infi ltration rates
ranging between 0.07 and 0.17 inches/hour with an average infiltration rate of less than 0.5 inches/hour. The
location and depth of proposed BMP basins will affect the infiltration rate. A more detailed di scussion of the site
specific infiltration testing can be found in our "Preliminary Infiltration Feasibility Study, Proposed 2-Lot
Development, Triton Street, Carlsbad, California," Report No. I 802-02-B-3.
2
Can infiltration greater than 0.5 inches per hour be allowed without increasing
risk of geotechnical hazards (slope stability, groundwater mounding, utilities,
or other factors) that cannot be mitigated to an acceptable level? The response
to this Screening Question shall be based on a comprehensive evaluation of
the factors presented in Appendix C.2.
Provide basis:
□
Design Infiltration rates at the project site are below 0.5 inches/hour: as such this screening question does not
control the feasibility of infiltration at the project site and is not applicable.
Criteria
3
Form 1-8 Page 2 of 4
Screening Question
Can infiltration greater than 0.5 inches per hour be allowed without increasing
risk of groundwater contamination (shallow water table, storm water
pollutants or other factors) that cannot be mitigated to an acceptable level?
The response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
Provide basis:
Yes No
□
Design Infiltration rates at the project site are below 0.5 inches/hour. Infiltration at a rate greater than 0.5
inches/hour is not feasible for this project. As such, this screenin g ques tion does not control the feasibility of
infiltration at the project site.
4
Can infiltration greater than 0.5 inches per hour be allowed without causing
potential water balance issues such as change of seasonality of ephemeral
streams or increased discharge of contaminated groundwater to surface
waters? The response to this Screening Question shall be based on a
comprehensive evaluation of the factors presented in Appendix C.3.
Provide basis:
□
Des ign infiltration rates are less than 0.5 inches/hour. Infiltration at a rate greater than 0.5 inches/hour is not
feasible fo r this project. As such, this screening question does not control the feasibi lity of infiltration at the project
site. Per Section C.4.4 of the BMP Design Manual, final determination should be made by the project design
engineer.
Part 1
Result*
If all answers to rows 1-4 are "Yes" a full infiltration design is potentially feasible.
The feasibility screening category is Full Infiltration
If any answer from row 1-4 is "No", infiltration may be possible to some extent but
would not generally be feasible or desirable to achieve a "full infiltration" design.
Proceed to Part 2
No,
Proceed
~o part 2
*To be completed using gathered site information and best professional judgment considering the definition of MEP
in the MS4 Permit. Additional testing and/or studies may be required by the City Engineer to substantiate findings.
Fonn 1-8 Page 3 of 4
Part 2 -Partial Infiltration vs. No Infiltration Feasibility Screening Criteria
Would infiltration of water in any appreciable amount be physically feasible without any negative
consequences that cannot be reasonably mitigated?
Criteria
5
Screening Question
Do soil and geologic conditions allow for infiltration in any appreciable rate
or volume? The response to this Screening Question shall be based on a
comprehensive evaluation of the factors presented in .Appendi-.,: C.2 and
Appendix D.
Provide basis:
Yes No
□
Site specific infiltration testing yielded preliminary design infiltration rates ranging between 0.07 and 0.17
inches/hour with an average rate of 0.11 inches/hour. In addition, the subsurface soils encountered are relatively
dense. Infiltration at the project site is anticipated to be partial infiltration. It is anticipated that over the lifetime
of the development the infiltration rates will further diminish. It is our current understanding that an
'appreciable' infiltration rate is interpreted to be an infiltration rate of 0.05 in/hr or greater. Therefore, in
consideration of the current interpretation, the project site locally does allow for infiltration in an 'appreciable'
rate or volume.
6
Can Infiltration in any appreciable quantity be allowed without increasing
risk of geotechnical hazards (slope stability, groundwater mounding, utilities,
or other factors) that cannot be mitigated to an acceptable level? The
response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendi..x C.2.
Provide basis:
□
Infiltration is potentially feasible within the tested areas without significantly increasing the risk of geotechnical
hazards provided appropriate mitigation/remedial grading measures are perfom1ed during site development/basin
construction. Detailed plans depicting proposed BMP types and locations were not available at the time of this
study. When detailed plans become available further investigation may be required to appropriately evaluate the
potential geotechnical hazards.
Criteria
7
Form 1-8 Page 4 of 4
Screening Question
Can Infiltration in any appreciable quantity be allowed without posing
significant risk for groundwater related concerns (shallow water table, storm
water pollutants or other factors)? The response to this Screening Question
shall be based on a comprehensive evaluation of the factors presented in
Appendix C.3.
Provide basis:
Yes No
~ □
Partial infiltration can be allowed without posing significant risk for groundwater related concerns, if the basin is
located at least ten (10) vertically above seasonal high groundwater. Groundwater is not expected to be located
within IO feet of the proposed infiltration surfaces onsite nor is expected to rise to within IO feet of the
infiltration surface.
8
Can infiltration be allowed without violating downstream water rights? The
response to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
Provide basis:
□
Based on the project location and site conditions, it is not anticipated that allowing infiltration onsite will violate
downstream water rights. However, per Section C.4.4 of the BMP Design Manual, final determination should
be made by the project design engineer.
Part 2
Result
*
If all answers from row 5-8 are "Yes", then partial infiltration design is potentially
feasible. The feasibility screening category is Partial Infiltration.
If any answer from row 5-8 is "No", then infiltration of any volume is considered to be
infeasible within the drainage area. The feasibility screening category is No Infiltration.
Yes,
Partial
Infiltration
is feasible
*To be completed using gathered site information and best professional judgment considering the definition of
MEP in the MS4 Permit. Additional testing and/or studies may be required by the City Engineer to substantiate
findings
PERCOLATION TEST DATA SHEET
Project: Triton Street
Test Hole No.: P-1 ------
Depth of Test Hole: 4.5 ft
Test Hole Dimensions (Inches)
Length 54 Width
Infiltration Test
Trial No. Start Time Stop Time
(hr and min) (hr and min)
1 7:15 7:45
2 7:45 8:15
3 8:15 8:45
4 8:45 9:15
5 9:15 9:45
6 9:45 10:15
7 10:15 10:45
8 10:45 11:15
9
10
11
12
13
14
15
•calculated via Porchet Method
0 30 60
Project No.: __ 1_8_0_2-_0_2_ Date:
Tested By: ___ s_s __ Water Temp.:
uses: SM Air Temp.:
19 Diameter 19
Time Interval (Pieziometric Surface in inches)
(min.) Start Depth End Depth Depth Change
30 48.00 45.00 3.00
30 49.50 46.75 2.75
30 50.00 47.75 2.25
30 50.50 48.00 2.50
30 50.75 48.50 2.25
30 50.50 48.25 2.25
30 50.75 48.75 2.00
30 50.50 48.75 1.75
90 120 150 180 210 240
Time Elapsed (min)
Average
Water Columr
50.06
43.11
43.11
43.11
43.11
43.11
43.11
43.11
270
7/11/2018
72
75
Pere Rate
(in./hr.)
3.75
3.33
2.70
2.97
2.66
2.67
2.36
2.08
300
nfiltration Rate•
(in./hr.)
0.520
0.546
0.447
0.496
0.447
0.447
0.397
0.347
330 360
PERCOLATION TEST DATA SHEET
Project: Triton Street
Test Hole No.: P-2 ------
Depth of Test Hole: 2.0 ft
Test Hole Dimensions (Inches)
Length 24 Width
Infiltration Test
Trial No. Start Time Stop Time
(hr and min) (hr and min)
1 7:30 8:00
2 8:00 8:30
3 8:30 9:00
4 9:00 9:30
5 9:30 10:00
6 10:00 10:30
7 10:30 11:00
8 11:00 11:30
9
10
11
12
13
14
15
•calculated via Porchet Method
0.60
Project No.:
Tested By:
uses:
12
Time Interval
(min.)
30
30
30
30
30
30
30
30
1802-02 Date:
ss Water Temp.:
SM Air Temp.:
Diameter 12
(Pieziometric Surface in inches)
Sta rt Depth End Depth Depth Change
24.00 22.00 2.00
23.50 20.50 3.00
23.25 21.75 1.50
24.00 22.25 1.75
24.00 22.75 1.25
23.75 22.75 1.00
24.00 23.00 1.00
24.00 23.00 1.00
Average
Water Columr
23.81
43.11
43.11
43.11
43.11
43.11
43.11
43.11
7/11/2018
72
75
Pere Rate
(in./hr.)
5.00
7.66
3.87
4.38
3.13
2.53
2.50
2.50
nfiltration Rate•
(in./hr.)
0.448
0.390
0.195
0.228
0.163
0.130
0.130
0.130
~o --------------------------------------------------------
0.40
0.20
0,10
0.00
0 30 60 90 120 150 180 210 240 270 300 330 360
Time Elapsed (min)
~ ()._
('.)
0 ~ (J) ..J 0:: i3
tii z 8 ii" ,_
~ a "' 1n ti UJ 0 0:: ()._ ;::: z ~ ..J ,_ z UJ CD 1n \;:
UJ ::;; :::, u 8 6 ::J CD :::, ()._
1n "' UJ (J)
? C:
;:Ii .,
"' ~
ti ('.)
CD :5
(J) :::,
0 ,_
(J)
\;:
c3
~
§
('.) z ii" 0 CD
(J) ('.)
<{
8AGS BORING NUMBER HA-1
PAGE 1 OF 1
ADVANCED GEOHCIINICAL SOLUTIONS, INC.
CLIENT Zajda Groui:1 PROJECT NAME Triton Street
PROJECT NUMBER 1802-02 PROJECT LOCATION Carlsbad California
DATE STARTED 7/10/18 COMPLETED 7/10/18 GROUND ELEVATION 338.8 ft HOLE SIZE 19
DRILLING CONTRACTOR AGS GROUND WATER LEVELS:
DRILLING METHOD Hand Auger AT TIME OF DRILLING --
LOGGED BY SS CHECKED BY SD AT END OF DRILLING --
NOTES AFTER DRILLING --
~ ATTERBERG I-'>!< w ~ ~ 0 (/) LIMITS z 0.. w;#! I-w u ~ffi (f)W o:::~ z (/) ~ I-I :i:c.9 (/) sl--:J t:: c;=-:JI-0 w z I-~ u wm 0Z__J 1--Z f= I-Q1--u 8l 0..¢' o..o MATERIAL DESCRIPTION zu f= t:: ~i'.;'.i w~ ~__J (/) __J~ __J :J:;; :J .e (J)W <( 0::: :J-:J 0.. :J mo -1--0::: w a~ (/)~ 1--o 0 (9 ~z 06 if Oz :J I :5 ::J (/)z (/)
<( ~o I-I-::J __J :5-w
(/) 0 u <( 0 0.. z
0 (/) 0.. u:
SM Ve!)£ Old Paralic De[1osits, {Qvo[110-11):
SIL TY SANDSTONE, fine grained, red brown to gray f------brown, damp to moist, dense; highly weathered, weakly
cemented, minor porosity
@ 2.0 in., Become red brown to yellow brown, slightly
moist, very dense; weathered, moderately cemented, iron
oxide staining
¾< ~ -BU M ,
REM.
e---1-lpHEAb
.... -
~ -
Total depth = 1.5 ft
No groundwater
Backfilled with soil cuttings
~ CL (.'.)
0 ali (/) -' Cl:'. c)
ti z 0 >-°' >-9 2 iii >-u w 0 Cl:'. CL i=: z ~ w -' >-z w ~ ~ w ::;; :::, 0 0 §
::J m :::, CL in Cl:'. w ;l u
ti (.'.)
m :5
(/) :::,
0 >-(/)
>-z
ci
~
9
(.'.) z °' 0 m
(/)
(.'.)
<(
8AGS
BORING NUMBER HA-2
PAGE 1 OF 1
ADVANCED GE01£CHNICAL SOUJJIONS. INC.
CLIENT Zajda Groui:1 PROJECT NAME Triton Street
PROJECT NUMBER 1802-02 PROJECT LOCATION Carlsbad California
DATE STARTED 7/10/18 COMPLETED 7/10/18 GROUND ELEVATION 336.5 ft HOLE SIZE 12
DRILLING CONTRACTOR AGS GROUND WATER LEVELS:
DRILLING METHOD Hand Auger AT TIME OF DRILLING --
LOGGED BY ss CHECKED BY SD AT END OF DRILLING --
NOTES AFTER DRILLING --
~ ATTERBERG I-':!i!. w ~ w~ 0 Cl) LIMITS z a.. I-w
(.) ~ffi (/) w a::~ z Cl) ~ I-I :i: 0 Cl) s I-::> t::c;:::-:::> I-0 w z I-~ (.) wCO 02...J 1-Z i= I-(.) O;? a..¢:' a..o MATERIAL DESCRIPTION zu 91-i= t:: ~G'.i w~ ~...J Cl) ...J~ ....1:::>~ :::> ,e, (l)w < a:: :::i-(.) ~
:::> O..:::> coo -1-a:: w Cl)~ 1-o 0 (:) ~z (.) ~ & Oz :::> I a~ :'.5 :J (/)z Cl)
< ~o I-I-:J ...J :'.5-w
Cl) 0 (.) < 0 a.. z
0 Cl) a.. u:::
SM Ve01 Old Paralic De11osits, {Qvo1110-11):
SIL TY SANDSTONE, fine grained, red brown to gray .... -brown, damp to moist, dense; highly weathered, weakly
cemented, minor porosity
-
-
-@ 0.5 ft., Becomes red brown to yellow brown, damp, very
dense; weathered, moderately cemented, iron oxide
staining .... -
.___L
-
-
-
BU :oRr; -
____l__
-
-
~ 1---
-
-
-
-
~
-
--
Total depth= 4.5 ft
No groundwater
Backfilled with soil cuttings
o.' (.')
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8AGS BORING NUMBER HA-3
PAGE 1 OF 1
ADVANCED GEOltCIINICAL SOUITIONS, INC.
CLIENT Zajda Grou11 PROJECT NAME Triton Street
PROJECT NUMBER 1802-02 PROJECT LOCATION Carlsbad California
DATE STARTED 7/10/18 COMPLETED 7/10/18 GROUND ELEVATION 336.5 ft HOLE SIZE 12
DRILLING CONTRACTOR AGS GROUND WATER LEVELS:
DRILLING METHOD Hand Auger AT TIME OF DRILLING -
LOGGED BY ss CHECKED BY SD AT END OF DRILLING --
NOTES AFTER DRILLING -
~ ATTERBERG I-w ~ ~ e..,, (/) LIMITS z 0.. UJ~ I-w (.) ~ffi (/) w a::~ z (/) ~ I-I :i: 0 (/) 51-::J t:: c;::-::JI-0 w z t-~ (.) wen 0Z...J 1-Z i= I-(.) 0~ 0.. ¢:' o..o MATERIAL DESCRIPTION zu 91-i= t:: ~ns w~ r:?. ...J (/) ...J::i: ...J ::J ~ ::J 5 (/)w <( a:: (.) e..,, ::J O..::J cnO -1-a:: w ::J-(/)::i: 0 oz a~ t-o (/) ('.) ::i:z (.)6 >-::J I ~::J (/)z <( a:: ::i:O I-I-::J....l ~-w
(/) 0 (.) <( 0 0.. z
0 (/) 0.. u:::
SM Ve!Y Old Paralic Deuosits, {Qvou10-11):
SIL TY SANDSTONE, fine grained, red brown to gray -brown, damp, dense; highly weathered, weakly cemented,
minor porosity
-@ 2.0 in., Becomes red brown to yellow brown, damp, very
dense; weathered, moderately cemented, iron oxide
-staining
-
1
Total depth = 1.0 ft
No groundwater
Backfilled with soil cuttings
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t1JAGS BORING NUMBER HA-4
PAGE 1 OF 1
ADVANCED GEotfCHNICAL SOlllJIONS. INC.
CLIENT Zajda Grour::, PROJECT NAME Triton Street
PROJECT NUMBER 1802-02 PROJECT LOCATION Carlsbad California
DATE STARTED 7/10/18 COMPLETED 7/10/18 GROUND ELEVATION 337.5 ft HOLE SIZE 12
DRILLING CONTRACTOR AGS GROUND WATER LEVELS:
DRILLING METHOD Hand Auger AT TIME OF DRILLING --
LOGGED BY ss CHECKED BY SD AT END OF DRILLING --
NOTES AFTER DRILLING --
~ ATTERBERG 1--w g w~ ~ (/) LIMITS z Cl.. 1--w u i'= ffi (/) w a::~ z (/)
i'= 1--I :i:0 (/) 5I--=> t:: c;::-=i 1--0 w z 1--~ u wm 0Z.J 1--Z i== 1--u 8l Cl.. 4: o...o MATERIAL DESCRIPTION z (.) 91--i== t:: Qi'.5 w~ (2.J (/) _J~ _J=i~ =i.S (f)W <( a:: =i-=i Cl..=:> mo -1--a:: w (/)~ 1--o 0 Oz a~ (/) (!) ~z u6 it: ~o =i I :J_J ::5 :J Wz w <( 1--1--::s-(/) 0 u <( 0 Cl.. z
0 (/) Cl.. u:::
~ SM Artificial Fill -Undocumented, {afu): n SIL TY SAND, fine grained, medium brown to red brown, I
SM damp, loose to medium dense
Ve!)£ Old Paralic Dej;!osits, {Qvoj;!10-11):
SIL TY SANDSTONE, fine grained, red brown to yellow
brown, damp, very dense; weathered, moderately
cemented, iron oxide staining
__.1__
~ -
~ -
,... -
-
2
Total depth= 2.0 ft
No groundwater
Backfilled with soil cuttings