HomeMy WebLinkAboutCT 2019-0004; 330 CHINQUAPIN AVE; GEOTECHNICAL INVESTIGATION; 2018-11-30,.
'
GR □Ufl
DELTA
APR 1 7 2019
C\TY OF CARLSBAD
PLANNING DIVISION
REPORT OF GEOTECHNICAL INVESTIGATION
330 CHINQUAPIN AVENUE
CARLSBAD, CALIFORNIA
Prepared for
Mr. Jeff Galizio
330 Chinquapin Avenue
Carlsbad, CA 92008
Prepared by
GROUP DELTA CONSULTANTS, INC.
9245 Activity Road, Suite 103
San Diego, California 92126
Project No. 5D589
November 30, 2018
• • .. i, • • • • ' -• f.. • I • • I._. .. ..
GR□UP DEL TA
November 30, 2018
Mr. Jeff Galizio
330 Chinquapin Avenue
Carlsbad, CA 92008
SUBJECT: REPORT OF GEOTECHNICAL INVESTIGATION
330 Chinquapin Avenue
Carlsbad, California
Mr. Galizio:
We are pleased to submit this geotechnical investigation for the proposed multi-family
development and associated improvements at 330 Chinquapin Avenue in Carlsbad, California. Our
investigation was conducted in general accordance with our proposal (GDC, 2018). No adverse or
unusual geotechnical conditions were identified in our investigation that would preclude
construction, or require the use of special construction methods. Specific conclusions regarding
the potential geotechnical constraints at the site, and geotechnical recommendations for grading,
foundation, and pavement design are provided in the following report.
We appreciate this opportunity to be of continued professional service. Feel free to contact the
office with any questions or comments, or if you need anything else.
GROUP DELTA CONSULTANTS
l!~P-E. 82035
~~
James C. Sanders, C.E.G. 2258
Project Engineer Associate Engineering Geologist
Distribution: (1) Addressee, Mr. Jeff Galizio (jcgaliziol@gmail.com)
9245 Activity Road, Suite 103, San Diego, CA 92126 TEL: (858) 536-1000
Anaheim -Irvine -Ontario -San Diego -Torrance
www.GroupDelta.com
Report of Geotechnical Investigation
330 Chinquapin Avenue
GDC Project No. SD589
November 30, 2018
Page i Mr. Jeff Galizio
TABLE OF CONTENTS
1.0 INTRODUCTION .......................................................................................................... 1
1.1 Scope of Services ...................................................................................................... 1
1.2 Site Description ........................................................................................................ 2
1.3 Proposed Development ........................................................................................... 2
2.0 FIELD AND LABORATORY INVESTIGATION ................................................................... 2
3.0 GEOLOGY AND SUBSURFACE CONDITIONS .................................................................. 3
3.1 Old Paralic Deposits .................................................................................................. 3
3.2 Fill ............................................................................................................................. 3
3.3 Groundwater ............................................................................................................ 4
4.0 GEOLOGIC HAZARDS .................................................................................................. 4
4.1 Ground Rupture ....................................................................................................... 4
4.2 Seismicity .................................................................................................................. 4
4.3 Liquefaction and Dynamic Settlement ..................................................................... 5
4.4 Landslides and Lateral Spreads ................................................................................ 6
4.5 Flooding, Seiches, and Tsunamis .............................................................................. 6
5.0 CONCLUSIONS ............................................................................................................ 6
6.0 RECOMMENDATIONS ................................................................................................. 7
6.1 Plan Review .............................................................................................................. 7
6.2 Grading Observation and Testing ............................................................................ 7
6.3 Earthwork ................................................................................................................. 7
6.3.1 Site Preparation ............................................................................................ 7
6.3.2 Improvement Areas ...................................................................................... 8
6.3.3 Building and Drive Areas .............................................................................. 8
6.3.4 Fill Compaction ............................................................................................. 9
6.3.5 Subgrade Stabilization .................................................................................. 9
6.3.6 Surface Drainage ........................................................................................ 10
6.3.7 Temporary Excavations .............................................................................. 10
6.4 Storm Water Infiltration ......................................................................................... 10
6.5 Foundation Recommendations .............................................................................. 11
t~ GROUP OEL T.A
Report of Geotechnical Investigation GDC Project No. 5D589
330 Chinquapin Avenue November 30, 2018
Mr. Jeff Galizia Page ii
6.5.1 Conventional Slab-on-Grade Foundation Recommendations .................. 11
6.5.2 Post-Tension Slab Foundations .................................................................. 11
6.5.3 Settlement .................................................................................................. 12
6.5.4 Lateral Resistance ....................................................................................... 12
6.5.5 Slope Setback ............................................................................................. 12
6.6 On-Grade Slabs ....................................................................................................... 13
6.6.1 Moisture Protection for Slabs .................................................................... 13
6.6.2 Exterior Slabs .............................................................................................. 14
6.6.3 Expansive Soils ............................................................................................ 14
6.6.4 Reactive Soils .............................................................................................. 14
6. 7 Earth-Retaining Structures ..........................................................•.......................... 15
6.7.1 Cantilever Walls .......................................................................................... 15
6.7.2 Wall Surcharges .......................................................................................... 15
6.8 Preliminary Pavement Design ................................................................................ 15
6.8.1 Asphalt Concrete (AC) Pavement ............................................................... 16
6.8.2 Portland Cement Concrete (PCC) Pavement ............................................. 16
6.8.3 Preliminary Permeable Interlocking Concrete Pavement (PICP) Design ... 16
6.9 Pipelines ................................................................................................................. 17
6.9.1 Thrust Blocks .............................................................................................. 17
6.9.2 Modulus of Soil Reaction ........................................................................... 17
6.9.3 Pipe Bedding ............................................................................................... 17
7.0 LIMITATIONS ............................................................................................................ 17
8.0 REFERENCES ............................................................................................................. 18
~~ GROUP CELT.A
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizio
LIST OF TABLES
Table 1
LIST OF FIGURES
Figure 1
Figure 2A
Figure 2B
Figure 3A
Figure 3B
Figure 4A
Figure 4B
Figure 5
Figure 6
LIST OF APPENDICES
Appendix A
Appendix B
Appendix C
TABLE OF CONTENTS (Continued)
2016 CBC Acceleration Response Spectra
Site Location Map
Exploration Plan
Improvement Plan
Local Geologic Map
Local Topographic Map
Fault Location Map
Local Flood Map
Pad Transition Details
Wall Drain Details
Field Exploration
Geotechnical Laboratory Testing
Storm Water Infiltration Testing
A GROUP CEl.. TA
GDC Project No. 5D589
November 30, 2018
Page iii
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizio
1.0 INTRODUCTION
GDC Project No. 5D589
November 30, 2018
Page 1
The following report presents the results of our geotechnical investigation for multiple new two-
story residential buildings and associated improvements at what is currently 330 Chinquapin
Avenue in Carlsbad, California. Carlsbad is a coastal city within San Diego County, as shown on the
Site Location Map, Figure 1. New two-story residential buildings and associated site improvements
including asphalt drive areas are proposed. The approximate locations of the subsurface
explorations completed for this investigation are shown in relation to the existing property and the
proposed improvements on the Exploration Plan and the Improvement Plan, in Figures 2A and 2B,
respectively. The local geology and topography of the site are provided in Figures 3A and 3B,
respectively.
The purpose of our investigation was to characterize the geotechnical conditions at the site,
provide preliminary infiltration testing, and provide geotechnical recommendations for demolition,
grading, and the design of the proposed structures, pavements, underground utilities, and
associated surface improvements. The recommendations provided herein are based on our recent
subsurface exploration, laboratory tests, engineering and geologic analyses, and our previous
experience with similar geologic conditions.
1.1 Scope of Services
This report was prepared in general accordance with the provisions of the referenced proposal
(GDC, 2018). In summary, we provided the following scope of services.
• A geologic reconnaissance of the surface characteristics of the site.
• A subsurface exploration of the site including six exploratory borings. Logs of the
explorations are provided in Appendix A.
• Geotechnical laboratory testing of selected soil samples collected from the borings.
The geotechnical laboratory test results are presented in Appendix B and, where
appropriate, shown on the logs in Appendix A.
• A feasibility study of storm water management in accordance with the City of
Carlsbad, BMP Design Manual dated February 16, 2016 (referred to hereon as
Design Manual). Storm water infiltration assessment conclusions are presented in
this report. A detailed account of the field testing and the completed Worksheet 1-
8: Categorization of Infiltration Feasibility Condition of the Design Manual are
presented in Appendix C.
• Engineering analysis of the field and laboratory data to help develop geotechnical
recommendations for site preparation, remedial earthwork, foundation, pavement
design, soil corrosion, and site drainage and moisture protection.
t:-l GROUP CELT.A
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizio
GDC Project No. SD589
November 30, 2018
Page 2
• Preparation of this report summarizing our findings, conclusions and geotechnical
recommendations for site development.
1.2 Site Description
The site is located at 330 Chinquapin Avenue, Carlsbad, California. The property is bordered on the
north, west, and east by multi-family residential developments, and on the south by Chinquapin
Avenue, as shown in Figure 2A. The improvements will be located throughout the property, as
shown in Figure 2B. The site is currently occupied by a one-story single-family residence and a
lightly landscaped yard with small site walls, all of which will need to be demolished prior to
development. Based on the available plans and our site reconnaissance, the site also contains
existing subsurface utilities. Much of the site is relatively flat with surface elevations typically
ranging from about SO to 54 feet above mean sea level (MSL), as shown on the Local Topographic
Map, Figure 3B.
1.3 Proposed Development
Preliminary plans indicate the improvements will include four new two-story residential buildings,
with asphalt concrete paved driveways and parking areas. The new buildings are anticipated to be
supported by post-tension concrete slabs. Other site improvements will include drive areas and
exterior flatwork areas, storm water best management practices (BMPs), and a variety of
underground utilities. Retaining structures may be utilized in order to create the proposed building
pad and driveway areas.
Site development will begin with the demolition of the existing single-family house, site walls, and
existing asphalt driveway. Existing subsurface utilities that will be abandoned, or that may
otherwise interfere with the new improvements, will be relocated or removed. Remedial grading
will then be conducted to prepare the site for the planned improvements.
2.0 FIELD AND LABORATORY INVESTIGATION
The field investigation program began with a geologic reconnaissance of the site, and a subsurface
exploration on October 10, 2018. Six exploratory borings were advanced. The maximum depth of
exploration was approximately 21½ feet. A detailed description of the field work and the
associated boring logs are provided in Appendix A.
Soil samples were collected from the borings for geotechnical laboratory testing and analyses. The
testing program included gradation analysis, moisture content and dry density, and Atterberg
Limits to aid in material classification using the Unified Soil Classification System (USCS). Expansion
Index, R-Value, and Corrosivity testing were conducted to aid in preliminary foundation and
sitework design. Direct shear tests were conducted to aid in characterization of soil strength. The
geotechnical laboratory test results are shown in Appendix B.
t~ GRCUP CEL TA
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizia
GDC Project No. SD589
November 30, 2018
Page3
One boring was converted to a borehole percolation test to determine preliminary infiltration
rates. At the time of the investigation, no plans showing the type or location of proposed BMPs
were available; however, we were told that preliminary plans place a shallow BMP along the front
of the property. The test location was in a landscaped area just beyond the top of the site wall
near Chinquapin Avenue where BMPs are most likely to be located; the test elevation was selected
to mimic shallow infiltration basins. The location of the test is shown on Figures 2A and 2B. A more
detailed discussion, the results of the test, and our opinion on the feasibility of on-site infiltration
are presented in Appendix C.
3.0 GEOLOGY AND SUBSURFACE CONDITIONS
The subject site is located within the Coastal Plain portion of the Peninsular Ranges geomorphic
province of southern California. The Peninsular Ranges are characterized by a series of northwest
trending mountain ranges separated by valleys, with a coastal plain of subdued landforms. The
mountain ranges are underlain primarily by Mesozoic metamorphic rocks that were intruded by
plutonic rocks of the southern California batholith, while the coastal plain is underlain by
subsequently deposited marine and non-marine sedimentary formations. The general geology and
topography in the site vicinity are shown in Figures 3A and 3B. The geologic units beneath the
subject site are described below.
3.1 Old Paralic Deposits
The site is underlain at depth by Old Paralic Deposits, unit 6-7 (map symbol Qop5-1), as shown on
the Local Geologic Map, Figure 3A (USGS, 2007). The formation consists of silty to poorly-graded
sandstone with occasional beds of gravel and cobble. It is medium dense to very dense based on
the corrected SPT blow count data. The soils are typically yellowish to reddish brown in color,
moist, and fine grained. The sandstone ranges from friable to moderately cemented with
occasional localized zones of strongly cemented material.
3.2 Fill
Variable amounts of undocumented fill were encountered in our exploratory borings. The deepest
fill was found in boring 8-2 (approximately seven feet). This may be due to the proximity of the
boring to the adjacent lower property. It appears the subject property may be graded with thicker
fill on the eastern side to create a level pad on a west-east descending natural slope.
The undocumented fill we encountered was most commonly observed to consist of silty and clayey
sand (SC). Undocumented fill refers to soil that appears to have been placed as fill during
construction activities at some time in the past, with no record of how it was placed. Based on
corrected Standard Penetration Testing (NGO), the fill is considered to be medium dense in
consistency. Based on hand probing in the upper foot of the existing lot, some fill soils are loose.
The fill soils are considered to be unsuitable for the support of the new buildings and parking and
drive areas.
t-~ GRCLF CELT.A
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizio
3.3 Groundwater
GDC Project No. S0589
November 30, 2018
Page 4
No seepage or groundwater was encountered in the borings that we conducted for this
geotechnical investigation. Groundwater data obtained from the State Water Resources Control
Board water well database (Geo Tracker, 2017) does not show any studies within 1000 feet of the
subject property. However, based on a review of the data, the local topography, our site
investigation, and our previous experience we anticipate groundwater to be a few feet above
mean sea level in this area (more than 40 feet deep).
Groundwater seepage is not anticipated during construction. However, it should be noted that
changes in rainfall, irrigation practices or site drainage may produce seepage or locally perched
groundwater conditions at any location within the fill soil or formational units underlying the site.
Such conditions are difficult to predict, and are typically mitigated if and where they occur.
4.0 GEOLOGIC HAZARDS
The subject site is not located within an area previously known for significant geologic hazards.
Evidence of past landslides, liquefaction or active faulting at the site was not encountered in our
geotechnical investigation or literature review. We anticipate that the main geologic hazards at the
site will be associated with the potential for strong ground shaking due to a seismic event. Each of
the potential geologic hazards is described below.
4.1 Ground Rupture
Ground rupture is the result of movement on an active fault reaching the ground surface. The site
is not located within an Alquist-Priolo Earthquake Fault Zone. The nearest known active fault is the
Oceanside segment of the Rose Canyon fault zone located about 2 miles (3 km) southwest of the
site. No indications of active faulting were found in our reconnaissance or literature review.
Consequently, ground rupture is not considered to be a substantial geologic hazard at the site.
4.2 Seismicity
The site is approximately located at latitude 33.14818° north and longitude 117.34165°west. The
locations of known active faults within a 62-mile (100 km) radius of the site are shown on the Fault
Location Map, Figure 4A.
Based on the findings of the subsurface investigation, it is our opinion that a 2016 CBC Site Class D
will apply to the site. The USGS mapped spectral ordinates Ss and S1 equal 1.156 and 0.443,
respectively. For a Site Class D, the Site Coefficients Fa and Fv are equal to 1.038 and 1.557,
respectively. The design level spectral ordinates Sos and Soi equal 0.800 and 0.460, respectively.
The 2016 CBC Design and MCE Spectra for Site Class D are provided in Table 1.
The United States Geologic Survey has developed an interactive website that provides Next
Generation Attenuation (NGA) probabilistic seismic analyses based on the site location and shear
14' ~ GRCLP CELT.A
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizia
GDC Project No. 5D589
November 30, 2018
Page 5
wave velocity (USGS, 2017). Based on these analyses, we estimate that the peak ground
accelerations (PGA) with a 2, 5, and 10 percent probability of being exceeded in a SO-year period at
the site are approximately 0.S0g, 0.37g and 0.29g, respectively. These levels of risk are often
referred to as the Maximum Considered (MCE), Upper Bound (UBE) and Design Basis Earthquakes
(DBE), respectively. The peak ground acceleration from the design spectrum may be taken as 40
percent of Sos or 0.32g.
4.3 Liquefaction and Dynamic Settlement
Liquefaction involves the sudden loss in strength of a saturated, cohesionless soil (sand and non-
plastic silts) caused by the build-up of pore water pressure during cyclic loading, such as that
produced by an earthquake. Typically, liquefaction occurs in areas where there are loose to
medium dense sands and silts, and where the depth to groundwater is less than SO feet from the
ground surface.
Dynamic Settlement is a process in which a deposit of loose soil densities during the vibrations
induced by the occurrence of earthquakes or other sources of ground shaking. Soils subject to
dynamic settlement typically consist of cohesionless soil (sands and non-plastic silts), but such soils
do not have to be saturated. To settle, the soils must be subjected to ground shaking of sufficient
magnitude and duration.
In summary, three simultaneous conditions are required for liquefaction, two for dynamic
settlement:
• Historic high groundwater within SO feet of the ground surface (liquefaction only)
• Vulnerable soils such as loose to medium dense sands and non-plastic silts
• Strong shaking, such as that caused by an earthquake
The site is underlain by Old Paralic Deposits. However, our borings indicate that at least the upper
portion of the formation consists of a medium dense sand. Shallow groundwater was not
encountered.
We anticipate groundwater is roughly SO feet below existing grade. Also, based on our experience
in the area, SPT blow counts typically increase to above 30 (dense sand) with depth of more than
20 or 30 feet. Therefore, the potential for liquefaction to adversely affect the site is considered to
be negligible. Using these assumptions in conjunction with SPT blow count data obtained during
this investigation, we have estimated dry sand seismic settlement with the Pradel method (Pradel,
1998). Our analysis suggest settlement associated with dry sand seismic settlement is less than½-
inch. Therefore, the potential for dynamic settlement to adversely affect the site is considered to
be negligible
~~ GROUP CEL TA
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizio
4.4 Landslides and Lateral Spreads
GDC Project No. 5D589
November 30, 2018
Page6
Evidence of ancient landslides or slope instabilities were not observed during our literature review
or site reconnaissance. The site is relatively flat-lying or gently sloping, and is not considered to be
susceptible to landslides or lateral spreads.
4.5 Flooding, Seiches, and Tsunamis
The site is not located within a FEMA 100-year flood zone, as shown on the Local Flood Map,
Figure 4B. The site is not located in a dam inundation zone, and is not located below any lakes or
confined bodies of water. Therefore, the potential for earthquake induced flooding or seiches at
the site is low. Given the elevation of the site, the potential for damage due to tsunamis is
considered remote. The Tsunami Emergency Response Planning Zone is also shown in Figure 4B.
5.0 CONCLUSIONS
The planned development appears to be feasible from a geotechnical perspective, provided that
appropriate measures are implemented during construction. Several geotechnical conditions will
need to be addressed during fine grading of the site.
• Undocumented fill soils cover the site. These materials are loose to medium dense, and
may be susceptible to settlement under increased loads, or due to an increase in moisture
content from site irrigation or changes in drainage conditions. The undocumented fill will
need to be removed and replaced with compacted fill beneath the new improvements.
• In general, on-site soils are considered suitable for reuse in compacted fills, with the
exception of soil containing vegetation, demolition debris, or other deleterious materials.
• Based on the infiltration testing presented in Appendix C, on-site soils likely allow for storm
water infiltration. The preliminary infiltration rate was determined to be about one inch
per hour. The granular nature of the on-site soils are believed to be associated with the
relatively high infiltration rate we measured at the site.
• The planned surface improvements may also be underlain by compressible undocumented
fill soils. All of the compressible fill soils within the recommended influence zones should
be excavated and replaced with compacted fill under the testing and observation of the
geotechnical consultant prior to development.
• All of the new building pads should be over-excavated at least 3 feet below finish pad
grade, based on conditions observed by the geotechnical consultant during grading.
Additional remedial excavation depths may be required for some building areas in order to
remove deeper compressible undocumented fill soils, or mitigate the presence of cut/fill
transitions depending upon the conditions observed by the geotechnical consultant during
grading.
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizia
GDC Project No. 5D589
November 30, 2018
Page 7
• There are no known active faults located beneath the subject site, and the potential for
ground rupture to adversely impact the development is remote. Other geologic hazards
that may impact site development are primarily associated with the potential for strong
ground shaking from an earthquake on the Rose Canyon fault zone. The shaking hazard
may be mitigated by structural design in accordance with the applicable building code.
6.0 RECOMMENDATIONS
The remainder of this report presents recommendations regarding earthwork construction and
design of the proposed structures and associated improvements. These recommendations are
based on empirical and analytical methods typical of the standards of practice in southern
California. If these recommendations do not to appear to cover a specific feature of the project,
please feel free to contact our office for additions or revisions.
6.1 Plan Review
We recommend that the grading, storm water BMP, and foundation plans be reviewed by Group
Delta Consultants prior to construction.
6.2 Grading Observation and Testing
Foundation and grading excavations should be observed by the project geotechnical consultant.
The geotechnical consultant should also conduct sufficient testing of fill and backfill during grading
and improvement operations to support their professional opinion as to compliance with the
compaction recommendations. Such observations and tests are considered essential to identify
field conditions that differ from those anticipated by this investigation, to adjust designs to the
actual field conditions, and to determine that the construction is completed in general accordance
with the governing geotechnical recommendations.
6.3 Earthwork
Grading and earthwork should be conducted in general accordance with the requirements of the
current California Building Code. The following recommendations are provided regarding specific
aspects of the proposed earthwork construction. These recommendations should be considered
subject to revision based on the conditions observed by the geotechnical consultant during
grading.
6.3.1 Site Preparation
General site preparation should begin with the removal of deleterious materials from the site.
Deleterious materials include existing structures, foundations, pavements, slabs, trees, vegetation,
trash, contaminated soil and other demolition debris. Existing subsurface utilities that will be
abandoned should be removed and the excavations backfilled and compacted as described in the
section titled Fill Compaction. Alternatively, the abandoned pipes may be grouted with a two-sack
sand-cement slurry under the observation of the geotechnical consultant.
(_~ GRCUP CELT.A
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizio
6.3.2 Improvement Areas
GDC Project No. 5D589
November 30, 2018
Page 8
A minimum of two feet of material with an Expansion Index of 20 or less is recommended beneath
all new pavement sections, concrete sidewalks, and exterior improvements, including flatwork
areas. In order to accomplish this objective in areas that will not otherwise be over-excavated, the
upper 12-inches of soil below the slab subgrade elevations may be excavated and stockpiled on
site. The exposed subgrade should then be observed and tested by the geotechnical consultant. If
soil with an Expansion Index above 20 is encountered, the expansive soil should be excavated and
replaced with very low expansion material. The exposed subgrade should then be scarified 12
inches, brought to above optimum moisture content, and compacted as described in the section
titled Fill Compaction. Subgrade compaction for sidewalks and pavement areas should be
conducted immediately prior to placing concrete or base.
If loose soil, yielding subgrade, or deleterious material is encountered within two feet of finish
subgrade elevations, additional remedial excavations may be recommended, based on the
conditions observed by the geotechnical consultant during grading.
6.3.3 Building and Drive Areas
Potential geotechnical constraints within the proposed building and drive areas include the
presence of potentially compressible undocumented fill and potential transitions between cut and
fill beneath the new building slabs.
The undocumented fill throughout the site is considered to be potentially compressible. In all areas
of proposed fill placement, parking and drive areas, and buildings, all of the compressible
undocumented fill soils should be excavated under geologic observation. Remedial excavations
should be conducted as necessary to excavate and compact all of the existing undocumented fill
within an area bounded by a two-foot horizontal distance outside the improvement footprint.
Typical remedial excavation depths are anticipated to be on the order of three to five feet,
although fills of seven feet deep were observed in boring B-2, as discussed in the section titled
Geology and Subsurface Conditions1 and in Appendix A. The actual remedial excavation depths may
vary depending upon the conditions observed by the project geologist during grading.
Once the compressible soils have been excavated and deleterious materials removed, the bottom
of the excavation should expose formational material, as verified by the project geologist during
grading. The exposed formation should then be scarified, brought to slightly above optimum
moisture content, and then compacted as described in the section titled Fill Compaction. The
stockpiled soils may then be replaced as a uniformly compacted fill to the plan finish grades.
In addition to removing and compacting undocumented fill soils, a minimum of three feet of
compacted fill with an Expansion Index of 20 or less is recommended beneath all new building
slabs-on-grade. In order to accomplish this objective, the building pads should be over-excavated
to a depth of H/2, where H is the maximum depth of compacted fill beneath the building as
determined by the project geotechnical consultant during grading. Details regarding the required
tl C:iRCUP CEL TA
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizio
GDC Project No. 5D589
November 30, 2018
Page 9
over-excavations are presented in Pad Transition Details, Figure 5. The over-excavation (H/2)
should be at least three feet deep, and need not extend more than ten feet below slab subgrade
elevations. The over-excavation should extend at least five feet (measured horizontally) beyond
the perimeter of the building foundations, including any exterior isolated columns, as shown in
Figure 5. The stockpiled soil that is free of deleterious materials may then be replaced as uniformly
compacted fill to the planned finish pad grades. The upper three feet of building slab subgrade soil
(including the area within two feet of the building perimeter) should consist of a very low
expansion (El<20) compacted structural fill as described in the section titled Fill Compaction. We
anticipate that the planned foundations for the new buildings will bear directly within compacted
fill.
6.3.4 Fill Compaction
All fill and backfill should be placed at slightly above optimum moisture content using equipment
that is capable of producing a uniformly compacted product. The minimum recommended relative
compaction is 90 percent of the maximum dry density based on ASTM 01557. Sufficient
observation and testing should be performed by the geotechnical consultant so that an opinion
can be rendered as to the compaction achieved. Rocks or concrete fragments greater than six
inches in maximum dimension should not be used in structural fill.
Imported fill sources should be observed prior to hauling onto the site to determine the suitability
for use. In general, imported fill materials should consist of granular soil with less than 35 percent
passing the No. 200 sieve based on ASTM C136 and an Expansion Index less than 20 based on
ASTM 04829. Samples of the proposed import should be tested by the geotechnical consultant in
order to evaluate the suitability of these soils for their proposed use. During grading operations,
soil types may be encountered by the contractor that do not appear to conform to those discussed
within this report. The geotechnical consultant should be notified to evaluate the suitability of
these soils for their proposed use.
A two-sack sand and cement slurry may also be used for structural fill as an alternative to
compacted soil. It has been our experience that slurry is often useful in confined areas which may
be difficult to access with typical compaction equipment. Samples of the slurry should be
fabricated and tested for compressive strength during construction. A minimum 28-day
compressive strength of 100 pounds per square inch (psi) is recommended for the two-sack sand
and cement slurry.
6.3.5 Subgrade Stabilization
All excavation bottoms should be firm and unyielding prior to placing fill. In areas of saturated or
"pumping" subgrade, a layer of geogrid such as Tensar BX-1200 orTerragrid RX1200 may be placed
directly on the excavation bottom, and then covered with at least 12-inches of open-graded
crushed rock, followed by 12-inches of minus ¾-inch well-graded aggregate base. Once the
excavation is firm enough to attain the required compaction within the base, the remainder of the
excavation may be backfilled using either compacted soil or aggregate base.
t~ GRCJLP CEL TA
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizio
6.3.6 Surface Drainage
GDC Project No. SD589
November 30, 2018
Page 10
Slope, foundation, and slab performance depends greatly on how well surface runoff drains from
the site. This is true both during construction and over the entire life of the structure. The ground
surface should be graded so that water flows rapidly away from the structures and slope tops
without ponding. The surface gradient needed to achieve this may depend on the prevailing
landscaping. Planters should be built so that water will not seep into the foundation, slab, or
pavement areas. If roof drains are used, the drainage should be channeled by pipe to storm drains,
or discharge at least ten feet from buildings. Irrigation should be limited to the minimum needed
to sustain landscaping. Excessive irrigation, surface water, water line breaks, or rainfall may cause
perched groundwater to develop within the underlying soil.
6.3.7 Temporary Excavations
Temporary excavations are anticipated for the construction of the proposed utilities. All
excavations should conform to Cal-OSHA guidelines. Temporary slopes should be inclined no
steeper than 1:1 for heights up to ten feet. Higher temporary slopes, or any excavations which
encounter seepage, should be evaluated by the geotechnical consultant on a case-by-case basis.
6.4 Storm Water Infiltration
Our investigation included a feasibility study of storm water management in accordance with the
Design Manual. The evaluation consisted of test borings, laboratory testing, infiltration testing, and
an evaluation of feasibility for on-site storm water infiltration.
Group Delta advanced six borings (B-1 through 8-5 and 1-1) to a maximum depth of 21½ feet to
evaluate soil characteristics and the depth of groundwater across the site. Figures 2A and 28 show
the locations of these borings. Based on observations and sampling blow counts, the density of the
soils varied from loose to very dense. Groundwater was not encountered in our investigation. A
descriptive log for each boring is shown in Appendix A.
A disturbed soil sample was obtained from the infiltration test boring for particle size distribution
testing to evaluate the physical characteristics of the soils. The soils tested were classified as silty
sand (SM) per ASTM D2487. The test results are presented in Appendix A and B.
Group Delta performed field testing using the Borehole Percolation Test referenced in the Design
Manual. We completed a field test (1-1) that is discussed in detail in Appendix C, and the results are
shown in Figures C-1.1 and C-1.2.
The site and subsurface conditions, including our field testing, were reviewed relative to the
criteria stated in Worksheet 1-8: Categorization of Infiltration Feasibility Condition. The soils tested
appeared to be relatively permeable. The granular nature of the on-site soils are believed to be
associated with the relatively high infiltration rate we measured at the site.
t-l GROUP CEL TA
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizio
GDC Project No. 5D589
November 30, 2018
Page 11
Based on the preliminary test results, infiltration at the test location would be feasible. A detailed
study of the BMP location with respect to existing and planned utilities, walls, and other
improvements should be considered during the design development stage. In addition, storm
water contaminants and water balance issues should be considered in the BMP design. Due to
variability of the soil at the project site, design of the BMP's should consider the location and
results of the preliminary infiltration test.
The conclusion and recommendations for storm water infiltration are based on the assumption
that soil and groundwater conditions do not deviate appreciably from those locally observed by
Group Delta. If remedial grading results in different soil conditions in proposed infiltration zones,
further testing may be warranted. The results should only be considered valid for the design
assumptions used for testing, including the location and elevation of the soils tested, and the
amount of pressure head in the test. These results may not be-applicable if significant changes to
the design occur. A detailed account of the test method, including the assumptions made, is
presented in Appendix C.
6.5 Foundation Recommendations
The foundations for the new buildings should be designed by the project structural engineer using
the following geotechnical parameters. These are only minimum criteria, and should not be
considered a structural design, or to preclude more restrictive criteria of governing agencies or the
structural engineer. All foundations for the new structures are anticipated to bear within
compacted fill.
6.5.1 Conventional Slab-on-Grade Foundation Recommendations
Allowable Bearing:
(Compacted Fill)
Minimum Footing Width:
Minimum Footing Depth:
Minimum Reinforcement:
6.5.2 Post-Tension Slab Foundations
2,000 lbs/ft2 (allow a½ increase for short-term wind
or seismic loads).
12inches
18 inches below lowest adjacent soil grade
Two No. 4 bars at top and bottom
Provided that remedial grading is conducted per our recommendations, most of the residential lots
at the site will be underlain by compacted fill with a low expansion potential (El<S0). The following
preliminary post-tension slab foundation design parameters are considered applicable to buildings
that will be underlain by such conditions. Note that these recommendations should be considered
preliminary, and subject to revision based on the conditions observed by the geotechnical
t~ GRCLF CELT.A
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizio
GDC Project No. 5D589
November 30, 2018
Page 12
consultant during grading of the site. The final foundation design parameters should be provided
in the as-graded geotechnical report after the site is graded.
Preliminary Post-Tension Slab Design Parameters:
Moisture Variation, em:
Differential Swell, ym:
Allowable Bearing:
6.5.3 Settlement
Center Lift:
Edge Lift:
Center Lift:
Edge Lift:
9.0feet
4.8/eet
0.7 inches
1.0inches
2,000 psf at slab subgrade
Provided that remedial grading is conducted as recommended in the section titled Earthwork,
total and differential settlement of the proposed structures is not expected to exceed one inch and
¾-inch in 40 feet, respectively. Additionally, dry sand settlement, as discussed in the section titled
Liquefaction and Dynamic Settlement, is anticipated to be less than ½-inch.
6.5.4 Lateral Resistance
Lateral loads against the structures may be resisted by friction between the bottoms of footings
and slabs and the soil, and passive pressure from the portion of vertical foundation members
embedded into compacted fill or formational materials. A coefficient of friction of 0.35 and a
passive pressure of 350 psf per foot of depth may be used.
6.5.5 Slope Setback
As a minimum, all foundations should be setback from any descending slope at least 8 feet. The
setback should be measured horizontally from the outside bottom edge of the footing to the slope
face. The horizontal setback may be reduced by deepening the foundation to achieve the
recommended setback distance projected from the footing bottom to the face of the slope. Note
that the outer few feet of all slopes are susceptible to gradual down-slope movements due to
slope creep. This will affect hardscape such as concrete slabs. We recommend that settlement
sensitive structures not be constructed within 5 feet of the slope top without specific review by
Group Delta.
Ii\ ~ GRCJUFI CEL TA
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizia
6.6 On-Grade Slabs
GDC Project No. SD589
November 30, 2018
Page 13
On-grade slabs should be designed by the project structural engineer. Building slabs should be at
least 5 inches thick, and should be reinforced with at least No. 3 bars on 18-inch centers, each way.
Slab thickness, control joints, and reinforcement should be designed by the structural engineer and
should conform to the requirements of the current CBC. The bearing soils are anticipated to be
predominately granular with a very low expansion potential (El<20).
If expansive soils are encountered during grading, the clayey subgrade soil should be over-
excavated, and two or three feet of very low expansive soils (El<20) should be placed directly
beneath the heave sensitive concrete slabs-on-grade, as described in the section titled
Improvement Areas and Building Areas, respectively.
6.6.1 Moisture Protection for Slabs
Concrete slabs constructed on grade ultimately cause the moisture content to rise in the
underlying soil. This results from continued capillary rise and the termination of normal
evapotranspiration. Because normal concrete is permeable, the moisture will eventually penetrate
the slab. Excessive moisture may cause mildewed carpets, lifting or discoloration of floor tiles, or
similar problems. To decrease the likelihood of problems related to damp slabs, suitable moisture
protection measures should be used where moisture sensitive floor coverings, equipment, or other
factors warrant.
The most common moisture barriers in southern California consist of two to four inches of clean
sand covered by 'visqueen' plastic sheeting. Two inches of sand are placed over the plastic to
decrease concrete curing problems. It has been our experience that such systems will transmit
approximately 6 to 12 pounds of moisture per 1000 square feet per day. The architect should
review the estimated moisture transmission rates, since these values may be excessive for some
applications, such as sheet vinyl, wood flooring, vinyl tiles, or carpeting with impermeable backings
that use water soluble adhesives. Sheet vinyl may develop discoloration or adhesive degradation
due to excessive moisture. Wood flooring may swell and dome if exposed to excessive moisture.
The architect should specify an appropriate moisture barrier based on the allowable moisture
transmission rate for the flooring. This may require a "vapor barrier" or a "vapor retarder".
The American Concrete Institute provides detailed recommendations for moisture protection
systems (ACI 302.lR-04). ACI defines a "vapor retarder" as having a minimum thickness of 10-mil,
and a water transmission rate of less than 0.3 perms when tested per ASTM E96. ACI defines a
"vapor barrier" as having a water transmission rate of 0.01 perms or less (such as a 15 mil
StegoWrap). The vapor membrane should be constructed in accordance with ASTM E1643 and
El 745 guidelines. All laps or seams should be overlapped at least 6 inches or per the manufacturer
recommendations. Joints and penetrations should be sealed with pressure sensitive tape, or the
manufacturer's adhesive. The vapor membrane should be protected from puncture, and repaired
per the manufacturer's recommendations if damaged.
ei C:iiRCLF CEL TA
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizia
GDC Project No. SD589
November 30, 2018
Page 14
The vapor membrane is typically placed over 4 inches of granular material. The material should
consist of a clean, fine graded sandy soil with roughly 10 to 30 percent passing the No. 100 sieve.
The sand should not be contaminated with clay, silt, or organic material. The sand should be proof-
rolled prior to placing the vapor membrane.
Based on current ACI recommendations, the concrete slab should be placed directly over the vapor
membrane. The common practice of placing sand over the vapor membrane may increase
moisture transmission through the slab, because it provides a reservoir for bleed water from the
concrete to collect. The sand placed over the vapor membrane may also move during placement,
resulting in an irregular slab thickness. When placing concrete directly on an impervious
membrane, it should be noted that finishing delays may occur. Care should be taken to assure that
a low water to cement ratio is used, and that the concrete is moist cured in accordance with ACI
guidelines.
6.6.2 Exterior Slabs
Exterior slabs and sidewalks should be at least four inches thick. Crack control joints should be
placed on a maximum spacing of ten-foot centers, each way, for slabs, and on five-foot centers for
sidewalks. The potential for differential movements across the control joints may be reduced by
using steel reinforcement. Typical reinforcement for exterior slabs would consist of 6x6
W2.9/W2.9 welded wire fabric placed securely at mid-height of the slab.
6.6.3 Expansive Soils
We anticipate that the proposed excavations will predominately generate mixtures of silty sand
and poorly-graded sand with silt. The Expansion Index test results of select samples are shown in
Figure B-2. It has been our experience that such materials typically have a very low expansion
potential based on common criteria (El<20). However, if expansive clay is encountered near finish
grade in building or heave sensitive improvement areas during site grading, the upper two feet of
clayey soil should be excavated and replaced with a very low expansion material (El<20). Expansion
Index testing should be conducted during grading of the site.
6.6.4 Reactive Soils
In order to assess the sulfate exposure of concrete in contact with the site soils, samples were
tested for water-soluble sulfate content, as shown in Figure B-3. The test results indicate that the
on-site soils have a negligible potential for sulfate attack based on commonly accepted criteria.
The sulfate content of the finish grade soils should be determined during fine grading. In order to
assess the reactivity of the site soils with buried metals, the pH, resistivity and chloride contents
were also determined (see Figure B-3). Resistivity tests suggest that the on-site soils are mildly
corrosive to ferrous metals, while chloride contents suggest a negligible potential for reaction with
metals. Typical corrosion control measures should be incorporated into design, such as providing
minimum clearances between reinforcing steel and soil, or sacrificial anodes for buried metal
structures. A corrosion consultant may be contacted for specific recommendations.
ti GROUP OEL TA
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizia
6. 7 Earth-Retaining Structures
GDC Project No. SD589
November 30, 2018
Page 15
Backfilling retaining walls with expansive soil can increase lateral pressures well beyond normal
active or at-rest pressures. We recommend that retaining walls be backfilled with soil that has an
Expansion Index of 20 or less. The select soil samples meet this criterion. Retaining wall backfill
should be compacted to at least 90 percent relative compaction based on ASTM D1557. Backfill
should not be placed until the retaining walls have achieved adequate strength. Heavy compaction
equipment, which could cause distress to the walls, should not be used. For general wall design,
an allowable bearing capacity of 2,500 lbs/ft2, a coefficient of friction of 0.40, and a passive
pressure of 350 psf per foot of depth is recommended.
6.7.1 Cantilever Walls
Cantilever retaining walls with level granular backfill may be designed using an active earth
pressure approximated by an equivalent fluid pressure of 35 lbs/ft3• The active pressure should be
used for walls free to yield at the top at least½ percent of the wall height. Basement walls that are
restrained so that such movement is not permitted should be designed for an at-rest earth
pressure of 55 lbs/ft3 (assuming level backfill). These pressures do not include seepage forces or
surcharges. All retaining walls should contain adequate backdrains to relieve hydrostatic pressures.
Typical wall drain details are shown Figure 6.
6.7.2 Wall Surcharges
In addition to the earth pressures recommended above, all retaining walls adjacent to vehicular
traffic zones should be designed to resist a uniform lateral pressure of 100 lb/ft2, resulting from an
assumed 300 lb/ft2 traffic surcharge behind the wall. If the vehicular traffic is kept 10 or more feet
away from the walls, the traffic surcharge may be neglected. Other surcharges within a 1:1 plane
extending back and up from the base of the wall should be accounted for in the wall design.
6.8 Preliminary Pavement Design
Pavement improvements include driveways, parking stalls, and a turn-around, all of which we
assume may be used as fire lanes as well. Pavement design options are provided below. In all
cases, the upper 12 inches of pavement subgrade should be scarified immediately prior to
constructing the pavements, brought to optimum moisture, and compacted to at least 95 percent
of the maximum dry density per ASTM D1557. Aggregate base should also be compacted to 95
percent of the maximum dry density. Aggregate base should conform to the Standard
Specifications for Public Works Construction (SSPWC), Section 200-2.
t~ GROUP OEL TA
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizia
6.8.1 Asphalt Concrete (AC) Pavement
GDC Project No. SD589
November 30, 2018
Page 16
Asphalt concrete pavement design was conducted in general accordance with the Caltrans Design
Method (Topic 608.4). Based on laboratory testing of on-site soils (Appendix B), an R-Value of 40
was assumed for design. The actual pavement section design may vary based on the actual
subgrade R-Values determined during grading in the new pavement subgrade areas. Asphalt
concrete should conform to Section 400-4 of the SSPWC and should be compacted to between 91
and 97 percent of the Maximum Theoretical or Rice Density per ASTM D2041.
Traffic Indices of 5.0 through 7 .0 were assumed for preliminary design purposes. The project civil
engineer should review these assumed Traffic Indices to determine if and where they apply to the
various new pavements proposed at the site. Based on a subgrade R-Value of 40, and the assumed
range of Traffic Indices, the following preliminary pavement sections would apply.
PAVEMENT TYPE TRAFFIC ASPHALT BASE
INDEX SECTION SECTION
Passenger Car Parking 5.0 31nches 41nches
Truck Traffic Areas 6.0 31nches 61nches
Heavy Traffic Areas 7.0 41nches 91nches
6.8.2 Portland Cement Concrete (PCC) Pavement
Concrete pavement design was conducted in general accordance with the simplified design
procedure of the Portland Cement Association. This methodology is based on a 20-year design life.
For design, it was assumed that aggregate interlock would be used for load transfer across control
joints. The subgrade materials were assumed to provide "medium" support. A preliminary Traffic
Index (T.I.) of 6.0 was used. Based on the assumptions described above, we recommend that the
PCC pavement sections at the site consist of at least 6 inches of concrete placed on subgrade.
Concrete pavements should be underlain by at least two feet of low expansion soil, as described in
the section titled Site Improvements.
6.8.3 Preliminary Permeable Interlocking Concrete Pavement (PICP) Design
Permeable Interlocking Concrete Pavers (PICP) are sometimes utilized on small sites to decrease
the percentage of impermeable surface on the site for storm water management purposes. If PICP
is found to be a viable design alternative to asphalt concrete in parking and drive areas, PICP
design, construction, and maintenance recommendations can be provided.
tl GROUP CEL TA
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizio
6.9 Pipelines
GDC Project No. 5D589
November 30, 2018
Page 17
The development will include a variety of pipelines such as water, storm drain and sewer systems.
Geotechnical aspects of pipeline design include lateral earth pressures for thrust blocks, modulus
of soil reaction, and pipe bedding. Each of these parameters is discussed separately below.
6.9.1 Thrust Blocks
Lateral resistance for thrust blocks may be determined by a passive pressure value of 350 lbs/ft2
per foot of embedment, assuming a triangular distribution. This value may be used for thrust
blocks embedded into compacted fill soils as well as the formational materials.
6.9.2 Modulus of Soil Reaction
The modulus of soil reaction (E') is used to characterize the stiffness of soil backfill placed along the
sides of buried flexible pipelines. For the purpose of evaluating deflection due to the load
associated with trench backfill over the pipe, a value of 2,000 lbs/in2 is recommended for the
general conditions, assuming granular bedding material is placed around the pipe.
6.9.3 Pipe Bedding
Typical pipe bedding as specified in the Standard Specifications for Public Works Construction may
be used. As a minimum, we recommend that pipes be supported on at least 4 inches of granular
bedding material such as minus ¾-inch crushed rock or disintegrated granite. Where pipeline or
trench excavations exceed a 15 percent gradient, we do not recommend that open graded rock be
used for bedding or backfill because of the potential for piping and internal erosion. For sloping
utilities, we recommend that coarse sand or sand-cement slurry be used for the bedding and pipe
zone. The slurry should consist of a 2-sack mix having a slump no greater than 5 inches.
7.0 LIMITATIONS
This report was prepared using the degree of care and skill ordinarily exercised, under similar
circumstances, by reputable geotechnical consultants practicing in similar localities. No warranty,
express or implied, is made as to the conclusions and professional opinions included in this report.
The findings of this report are valid as of the present date. However, changes in the condition of a
property can occur with the passage of time, whether due to natural processes or the work of man
on this or adjacent properties. In addition, changes in applicable or appropriate standards of
practice may occur from legislation or the broadening of knowledge. Accordingly, the findings of
this report may be invalidated wholly or partially by changes outside our control. Therefore, this
report is subject to review and should not be relied upon after a period of three years.
t.~ GROUP CELT.A
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizio
8.0 REFERENCES
GDC Project No. 5D589
November 30, 2018
Page 18
American Society of Civil Engineers (2017). Continuing Education, "Lessons Learned from the
Design, Construction and Maintenance of Permeable Pavements for Stormwater
Management -An ASCE Live Webinar': Presentation on December 4.
American Society for Testing and Materials (2017). Annual Book of ASTM Standards, Section 4,
Construction, Volume 04.08 Soil and Rock (I); Volume 04.09 Soil and Rock (If); Geosynthetics,
ASTM, West Conshohocken, PA, Compact Disk.
APWA (2016). Standard Specifications for Public Works Construction, Section 200-2.2, Untreated
Base Materials, Section 400-4, Asphalt Concrete: BNI, 761 p.
Boore, D.M. and G.M. Atkinson (2008). Ground-Motion Prediction Equations for the Average
Horizontal Component of PGA, PGV & 5% Damped PSA at Spectral Periods between 0.01s
and 10.0s, Earthquake Spectra, V.24, pp. 99-138.
Bowles, J. E. (1996). Foundation Analysis and Design, 5th ed.: McGraw Hill 1175 p.
California Department of Conservation, Division of Mines and Geology (1992). Fault Rupture
Hazard Zones in California, Alquist-Priolo Special Studies Zone Act of 1972: California
Division of Mines and Geology, Special Publication 42.
California Department of Conservation, Division of Mines and Geology (1993). The Rose Canyon
Fault Zone, Southern California, CDMG OFR 93-02.
California Department of Transportation (2009). Caltrans ARS Online (V2.3.06), Based on the
Average of (2) NGA Attenuation Relationships, Campbell & Bozorgnia (2008} & Chiou &
Youngs (2008) from http://dap3.dot.ca.gov/ ARS_ Online/
Campbell, K. W. and Y. Bozorgnia (2008). NGA Ground Motion Model for the Geometric Mean
Horizontal Component of PGA, PGV and PGD and 5% Damped Linear Elastic Response
Spectra for Periods Ranging from 0.01s and 10s, Earthquake Spectra, V.24, pp. 139-172.
Chiou, B. and R. Youngs (2008). An NGA Model for the Average Horizontal Component of Peak
Ground Motion and Response Spectra, Earthquake Spectra, V.24, pp. 173-216.
The City of Carlsbad (2016), BMP Design Manual, dated February 16.
GeoTracker (2017). California Environmental Protection Agency, State Water Resources Control
Board, http://geotracker.waterboards.ca. gov/.
Group Delta Consultants (2018). Proposal for Geotechnical Investigation, 330 Chinquapin, Carlsbad,
California 92008, Proposal No. SD18-061, September 11.
t~ GRCLP CEL TA
Report of Geotechnical Investigation
330 Chinquapin Avenue
Mr. Jeff Galizia
GDC Project No. SD589
November 30, 2018
Page 19
International Conference of Building Officials (2016). 2016 California Building Code.
Jennings, C. W. (1994). Fault Activity Map of California and Adjacent Areas with Locations and
Ages of Recent Volcanic Eruptions: California Division of Mines and Geology, Geologic Data
Map Series, Map No. 6.
Kennedy, M. P., and Tan, S. S. (2005). Geologic Map of the San Diego 30'x60' Quadrangle,
California: California Geologic Survey, Scale 1:100,000.
Pradel, D. (1998). Procedure to Evaluate Earthquake Induced Settlements in Dry Soils, Geotechnical
Journal, Vol. 124, No. 4, pp. 364 to 368.
Southern California Earthquake Center (1999). Recommended Procedures for Implementation of
DMG SP 117, Guidelines for Analyzing and Mitigating Liquefaction Hazards in California,
University of Southern California, 60 p.
Southern California Earthquake Center (2002). Recommended Procedures for Implementation of
DMG SP117, Guidelines for Analyzing and Mitigating Landslide Hazards in California,
University of Southern California, 110 p.
Treiman, J. A. (1984). The Rose Canyon Fault Zone --A Review and Analysis: California Division of
Mines and Geology unpublished report, 106 p.
Ultra-Unit Architectural Studio (2018). 330 Chinquapin, Site Plan, dated January 1.
United States Geological Survey (2007). Geologic Map of the Oceanside 30' x 60' Quadrangle,
California, Kennedy and Tan.
United States Geological Survey (USGS) (2017). U.S. Seismic Design Maps, last updated July 27,
from https://earthquake.usgs.gov/hazards/interactive/.
United States Geological Survey (USGS) (2017). Earthquake Hazards Program, Based on Three NGA
Relationships, Boore & Atkinson (2008), Campbell & Bozorgnia (2008) & Chiou & Youngs
(2008) from https://earthquake.usgs.gov/hazards/interactive/.
Wesnousky, S. G. (1986). Earthquakes, Quaternary Faults, and Seismic Hazard in California: Journal
of Geophysical Research, v. 91, no. 812, p. 12587-12631.
Youngs, R.R. and Coopersmith, K.J. (1985). Implications of Fault Slip Rates and Earthquake
Recurrence Models to Probabilistic Seismic Hazard Estimates, Bulletin of the Seismological
Society of America, vol. 75, no. 4, pp. 939-964.
t,l GROUP CELT.A
TABLES
t} GROUP CELT.A
TABLE 1-2016 CBC ACCELERATION RESPONSE SPECTRA
S,• 1.156 1 • short period (0.2 sec) mapped spectral response acceleration MCE Site Cass 8 (CIC 201D Fis. t&U.5(3) or USGS Ground Motion C.kulator) Sita 1at1tu<1e:I JJ.l48U .,. 0.4-43 1 • 1,0 sec period mapped spectral response acceleration MCE Site Cass B (CBC 2010 Fw, 1613.5(4) or USGS Ground Motion C.kuletor) .... ,.,, .. ttu ... ,1 -117.MllS i Site O.ss,. 0 • Site Class definition based on CBC 2010 T•bl• 1613,5,2 Seismic O.slcn tat<ao<Y:I D ! F.• 1.038 • Site Coeffldent applied to S. to account for soU type (CBC 2010 Table 16U.5.3(1))
F.,-1.557 • Site Coeffident applled to 51 to account for-soil type (CBC 2010 Table 1613.5.3(2))
.__ T,• 1.00 sec• Long Period Tnnsftlon Period (ASCE 7-45 Flcwe 22·16)
S,,,• 1.200 • site dass mod/fled short period (0.2 sec) MCE spectral response acceleration• F. x S. (CBC 2010 Eqn. 16-36)
i S..,• 0.690 • site dass modlfled 1.0 sec period MCE spectral response acceleration• F11x S1 (CBC 2t10 £qn. 16-37) .... 0.800 • llte dass modified dlort period (0.2 sec) Design spectnl response acceleration• 2/3 1 SMS (CBC 2007 Eqn. 115-31)
S.,• 0.460 • site dass modified 1,0 sec period Oesifl:n spectral response acc.eleration • 2/3 x SMl (CBC 2007 Eqn. 16-J9)
T.-0.115 sec• 0.2 SoJSm • Control Period (left end of peak) for AAS Curve (Section 11.4.5 ASCE 7.05)
T,• 0.575 sec• s ... /S-• Control Period lri1ht end of peak) for AAS Curve (Section 11.45 ASCE 7--05)
T o.-Ma
IHcondsl Sa II,) Se(I)
0.000 0.320 0.480
0.115 0.800 1.200
0.575 0.100 1.200 1.4 I I I 0.600 0.766 1.150
0.700 0.657 0.985 -0.100 0.575 0.162 -Design -0.900 0.511 0.766 1.2 -1,000 0.460 0.690
1.100 0.418 0.627 -
1.200 0.383 0.575 § \ ~
1.300 0.3S-4 0.531 C: 1 -MCE 1--
1.400 0.493 1.0 0.328 0 ~ 1.500 0.307 0.460 ..
1.600 0.287 0.431 ca ' ... ~ 1.700 0.270 0.4-06 Cl) ~ 1.100 0.255 0.383 ai 0.8 IX
1.900 0.242 0.363 (.) ~ 2.000 0.230 0.345 (.) <( ' " 2.100 0.219 0.321 ~ 1
""' :I! 2.200 0.209 0.314 I 2.300 0.200 0.300 ... 0.6 " (.) 2.400 0,192 0.287 8. 2.500 0.184 0.276 " ...
2.600 0.1n 0.265 (/) I°' .....
2.700 0.170 0.255 ... ""-2.800 0.164 0.246 0.4 .... .... 2.900 0.159 0.238 .... ~ .... 3.000 0.153 0.230
3.100 0.148 0.223 ---3.200 0.144 0.216 0.2 ---3.300 0.139 0.209
3.400 0.135 0.203
J.500 0.131 0.197
3.600 0.128 0.192
3.700 0.124 0.186 0.0
3.800 0.111 0.182 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 3.900 0.118 0.1n Period (seconds) 4,000 0.115 0.172
4.000 0.115 0.172
FIGURES
~'· GROUP DELTA
N
A
NO SCALE SITE LOCA110N MAP
ll£f.EIWjg; Google Earth (2016), Sa1elite Imagery dated 11/8116.
Bortng lderrlffk:atlon number.
Approidfflm tocatlon of bonnga.
lnflttrrion tHt I> number, Appro __ ., --.BEE.E.BfllQ;.: Google Earth (2016), Satelite lmage,y dated 1118/16.
2A
NO SCALE EXPLORATION PLAN
eonng ldenttfk:atlon number.
Approximate locdon of borinta.
~ teat ll nlJffltMir,
~locatlonof -.... ....
l!EE.E8£IKE; Ullrt-UnltArcllltedural Sl\ldlo, 330 Chinqull)in, Site Plan, dated 1/1/18.
; . ?7al', 11 1,r'
/ ,ui;, r/
I " I "J t I I I I., \ I I , " '"p
' ' I B◄ : ~ ' '
==-=:..=!::=~_,, :::::::::::::==-J I
NO SCALE IMPROVEMENT PLAN
Old parallc deposits, undivided (late to middle Pleistocene)
@Unlt2◄
lS:)Unlt8-7
G Aluvtal flood-91ain deposits
O•te Holocene)
B Old alluvial flood-t)laln deposits,
undMded
Oate to middle Pleistocene)
-Metesedimentery ond metavolcanlc rocks, undivided (late to middle Pleistocene)
~: Modil\ed from: USGS (2007), Geologle Map d 1he Ocaanllida 30' X 60' Quadrangle, Cafifomla.
N
A S0589
1&-0136
SA
NO SCALE LOCAL GEOLOGIC MAP
LOCAL TOPOGRAPHIC MAP
~ Modified from: United StatH Geological Survoy, Google Ear111 OYO<tay.
-~-~--.... ~
-"":,.~-
t N A
0102030405090
SCALE KM)
.. _
\
4A
FAULT LOCATION MAP
•
1ml
FEMNOWR 100-Year
Floodplain, Regional Study
2km
Tsunami Emergency
Response Planning Zone
Wt>~tfio~,J
Pb;,.1Cam1n0
R.i.ll
J!EEE8Ellg; Calif<mla Emergeocy Management Agency (2009~ W.b Haz•nl M;t;Qallon Porto/, FEW. Colifom/a SpocJ(lc Flood AIN,.
-
1Jogolc111d
Culdom1c1
Croulng,
al Car l•borJ
Golf Cour,;,,,
N
A
1.lc~I IL;Yrn P.:ilom...11
'"J:"J
LOCAL FLOOD MAP
TYPICAL CUT/FILL TRANSITION TYPICAL DEEP FILL TRANSITION
~
OVER-EXCAVATE TRANSITION
TO A DEPTH OF H/2 FEET
(3 FEET MINIMUM)
FILL
FORMATION
MAXIMUM
FILL DEPTH (H)
OVER-EXCAVATE TRANSITION
TO A DEPTH OF H/2 FEET
(10 FEET MAXIMUM)
1) Structures should not cross cut/fiH nor deep fiU transitions, due to the potential for adverse differential movement.
2) For building pads underlain by both cut/fill end deep fill transitions, the cut portion of the pads should be over-excavated to a depth of H/2,
where H is equal to the greatest depth of fl• beneath the building.
3) Over-excavations should ex1end et least 3 feet below pad grade, and do not need to extend more than 10 feet below pad grade.
◄) Over-excavations should extend at least 5 feet beyond the perimeters of the bulldlng foundations, Including any Isolated column footings.
MAXIMUM
FILL DEPTH (H)
FILL
FORMATION
A GRCJLP CELT.I\
__,_. .. ---. ... --_ _,oeou,aft SOSH
-Ae'TMn'-..O.MrlJ• ..... _--==-==--t
1a.o138
PAD TRANSITION DETAILS
ROCK AND FABRIC
ALTERNATIVE
MINUS 314-INCH CRUSHED ROCK
ENVELOPED IN FILTER FABRIC
(MIRAFI 140NL, SUPAC 4NP, OR
APPROVED SIMILAR)
HQIE.S.
4--INCH DIAM. PVC
PERFORATED PIPE
DAMP-PROOFING OR WATER•
PROOFING AS REQUIRED
1 CU. FT. PER LINEAR FOOT OF
MINUS 314--INCH CRUSHED
ROCK ENVELOPED IN
FILTER FABRIC
1) Perforated pipe should ouUet through a solid pipe to a free gravity outfan. Perforated pipe and ouUet pipe should have a fan of at least 1 %.
2) As an altemaUve to the perforaled pipe and outle~ weep-holes may be constructed. Weep-holes should be at least 2 Inches In diameter,
spaced no greater than 6 faet, and be located Just above grade at the bottom of wal.
3) Filter fabric should consist of Mlrafi 140N, Supac 5NP, Amoco 4599, or slmilar approved fabric. Filter fabric should be overlapped at least 6-lnches.
4) Geocomposlte panel drain should consist of Mlradraln 6000, J.ORaln 400, Supac DS-15, or approved similar produ~
PANEL DRAIN
ALTERNATIVE
WALL DRAIN DETAILS
· GRCUPDELTA
APPENDIX A
FIELD EXPLORATION
FIELD EXPLORATION
The subsurface exploration program included a visual and geologic reconnaissance of the site, the
drilling of five exploratory borings using a limited-access, hollow-stem drill rig, and the excavation
of one infiltration test hole by hand. The borings were conducted on October 10th, 2018. The
maximum depth of exploration was 21½ feet below surrounding grades. The approximate boring
locations are shown on the Exploration Plan, Figure 2A. Logs of the borings are provided in Figures
A-1 through A-6, immediately after the Boring Record Legends.
Borings B-1 through B-5 were conducted by Pacific Drilling Company using a Fraste LAR track
mounted drill rig. Infiltration test hole 1-1 was excavated using a hand-operated power auger. Drive
samples were collected from the drilled borings using an automatic hammer with an average
Energy Transfer Ratio (ETR) of about 83 percent. Disturbed samples were collected from the drilled
borings using a 2-inch outside diameter Standard Penetration Test (SPT) sampler. Less disturbed
samples were collected using a 3-inch outside diameter ring lined sampler (a modified California
sampler). These samples were sealed in plastic bags, labeled, and returned to the laboratory for
testing. For each sample, the number of blows needed to drive the sampler 12 inches was
recorded on the logs. The field blow counts (N) were normalized to approximate the standard 60
percent ETR, as shown on the logs (NGo). Bulk samples were also collected from the cuttings from
both drilled and hand dug borings. The boring logs are presented in Figures A-1 through A-6,
immediately following the Boring Record Legends.
The boring locations were determined by visually estimating, pacing and taping distances from
landmarks shown on the Exploration Plan. The approximate boring elevations were estimated from
Google Earth. The locations and elevations shown should not be considered more accurate than is
implied by the method of measurement used and the scale of the map. The lines designating the
interface between differing soil materials on the logs may be abrupt or gradational. Further, soil
conditions at locations between the excavations may be substantially different from those at the
specific locations we explored. It should be noted that the passage of time may also result in
changes in the soil conditions reported in the logs.
GRCUPDELTA
SOIL IDENTIFICATION AND HOLE IDENTIFICATION DESCRIPTION SEQUENCE
Holes are identified using the following
R e fer-to convention:
CII Section H-YY-NNN u ~ cij C: ... C: QI Ide ntification ·:; 0 Where: ::I -c c:r .::1 i" cii .a Components c,:s QI a. H: Hole Type Code U) ii: _, a:: 0
1 Group Name 2 .5 .2 3 .2.2 • YY: 2-digit year
2 Group Symbol 2 .5 .2 3 .2.2 • NNN: 3-digit number (001-999)
Description
Components Ho le T ype Code and Description
3 Consistency of 2 .5 .3 3 .2.3 • Hole Type Description Cohesive Soil Code
Apparent Density A Auger boring (hollow or solid stem, 4 of Cohesionless 2 .5.4 • bucket) Soil
5 Color 2 .5 .5 R • Rotary drilled boring (conventional)
Rotary core (self-cased wire-line, 6 Moisture 2 .5 .6 • RC continuously-sampled)
Percent or 2 .5 .7 3 .2 .4 • 0 RW Rotary core (self-cased wire-line, not Proportion of Soil continuously sampled)
7 Particle Size 2 .5 .8 2 .5 .8 • 0 p Rotary percussion boring (Air)
Particle Angularity 2 .5 .9 0 HD Hand driven (1 -inch soil tube)
Particle Shape 2 .5 .10 0 HA Hand auger
8 P lasticity (for fine-2 .5 .11 3 .2 .5 0 D Driven (dynamic cone penetrometer) grained soil) CPT Cone Penetration Test
9 Dry Strength (for 2 .5 .12 0 0 Other (note on LOTB) fine-grained soil)
Dilatency (for fine-10 2.5.13 0 grained soil)
11 Toughness (for 2 .5 .14 0 Descrietion Seguence Exameles: fine-grained soil)
1 2 Structure 2 .5 .15 0
13 Cementation 2 .5 .16 • SANDY lean CLAY (CL); very stiff;
Percent of yellowish brown; moist; mostly fines; Cobbles and 2 .5 .17 •
14 Boulders some SAND, from fine to medium; few
Description of gravels; medium plasticity; PP=2.75. Cobbles and 2 .5 .18 • Boulders
15 Consistency Field 2.5.3 • Well-graded SAND with SILT and
Test Result GRAVEL and COBBLES (SW-SM);
16 Additional 2 .5.19 0 dense; brown; moist; mostly SAND, Comments
Describe the soil using descriptive terms in from fine to coarse; some fine GRAVEL;
few fines; weak cementation; 10%
the order shown GRANITE COBBLES; 3 to 6 inches;
Minimum Reguired Seguence: hard; subrounded.
uses Group Name (Group Symbol); Consistency or Clayey SAND (SC); medium dense,
Density; Color; Moisture; Percent or Proportion of Soil; light brown; wet; mostly fine sand; little
Particle Size; Plasticity (optional). fines; low plasticity.
o = optional for non-Caltrans projects
Where aeelicable: Project No. S0589 Cementation; % cobbles & boulders; GR □Ufl
Description of cobbles & boulders; ~1 ~ 330 Chinquapin
Consistency field test result Carlsbad, CA 92008
REFERENCE: Caltrans Soil and Rock Logging, ~LTL\ Report of Geotechnical Investigation
Classification, and Presentation Manual (2010).
BORING RECORD LEGEND #1
GROUP SYMBOLS AND NAMES
.•, .. V,,...,_,_J ,R-' El
11'~ C.R.• l"l "It-$.a.•,..[)
PT Pf Al
rr ~t'lfS
CC ll ..,.. IIO\J\.OERS
IIOULOER5
DRILLING METHOD SYMBOLS
1H) Auger Drilling ~ Rotary Drilling
Definitions for Change in Material
Term
Material
Change
Definition
Change in material is observed in the
sample or core and the location of change
can be accurately located.
Estimated Change in material cannot be accurately
Material located either because the change is
Change gradational or because of limitations of
the drilling and sampling methods.
Soil / Rock Material changes from soil characteristics
Boundary to rock characteristics.
r"7I Dynamic Cone l::'..I or Hand Driven
Symbol
G,oupN~
A. 'El
El Diamond Core
FIELD AND LABORATORY TESTING
C Cc,n-:.nhd.:ihon CASTM D 2-t'\5)
CL Collup Polf•Ult.ll IA~ n ID 533])
CP c ompu 110n Cwv fCT .11 ltJ)
CR t.ouoston s .. 1tn10, Utk>rld stCH.ll;.11 CT,1417,
C II.I• ?•
cu C onsoll ldll-c.J UntJl,.Jln t\J Tno 1ul rA ft.1 0 47 7)
OS [),r+, I Sh<,ilr 1A:,n1O10801
El Exp-.111• ,ou IOOP (ASTM D 4829)
M ,lot-.turn Conc,-.n11A$ T .IO 22 hH
oc Urr1;:m1, Cont<•nt tA TM O 2074)
p Pe1111e.ib1lrty ,t. Tl.I o,
PA Pi01t1rlt. ",1ZP An..i t" (A Tr.1 0 412)
Pl Ltqwd l 111111 Pld<,ltt l 11n11 Pl,l h tty lntfPll'
tAASHTO T 8 • AA IITO T 901
PL Po,nl Lood Ind x 1ASTl,l O 5731l
R R Vdlut~I Tfl 'lOI)
SE :,.in,1 Equiv.ii nl 11,;rr.1217J
SG Spnc,h< r;, VI y 1MSHTO T 1001
SL 5h11nk,1,; L,m,I (ASH.I a 4:?71
SW ~Y,AH flO(ttOlttil fA TM O 4
UC Unconhr, Comp, -. ,.on Soll fASlt.1 () H,t,)
I Joc:011111 ,c.(1 ('nu1p1• ">:.tan RC)(' CA Tl t O J•t38J
UU Uncon,ohdotA<t Uod,01000 lflll>tt.11
ASll,I O 2850)
uw llo11w,,,,hllA"lf.l 471/)
SAMPLER GRAPHIC SYMBOLS
lv1 ~ Standard Peneiration Test (SPT)
IIJ Standard Cahforn1a Sampler
B Mod1f1ed Caltforn,a Sampler (2.4" m, 3" OD)
[I]
ff]
Shelby Tube
N Roe Core
I Bulk Sample
[]I] Piston Sampler
[I HO Rock Core
~ Other (see remar s)
WATER LEVEL SYMBOLS
First W ter Le el Reading (during drilling)
'Y S1at1c Water Level Reading (after drilling. dale)
REFERENCE: Caltrans Soil and Rock Logging, Classification,
and Presentation Manual (2010).
GR□UP
)
DELTA
Project No. S0589
330 Chinquapin
Carlsbad, CA 92008
Report of Geotechnical Investigation
BORING RECORD LEGEND #2
CONSISTENCY OF COHESIVE SOILS
Description Shear Strength (tsf) Pocket Penetrometer. PP Torvane. TV. Vane Shear. VS. Measurement (tsf) Measurement (tsf) Measurement (tsf)
Very Soft Less than 0.12 Less than 0.25 Less than 0.12 Less than 0.12
Soft 0.12 -0.25 0.25-0.5 0.12 -0.25 0.12 -0.25
Medium Stiff 0.25-0.5 0.5 • 1 0.25 -0.5 0.25 -0.5
Stiff 0.5 -1 1 • 2 0.5 -1 0.5 -1
Very Stiff 1 -2 2-4 I· 2 1 -2
Hard Greater than 2 Greater than 4 Greater than 2 Greater ihan 2
APPARENT DENSITY OF COHESION LESS SOILS MOISTURE
Description SPT ~(blows / 12 inches) Description Criteria
Very Loose 0-5 Dry No dlscemable moisture
Loose 5 -10
Medium Dense 10 • 30 Moist Moisture present. but no free water
Dense 30-50 Wet Visible free water
Very Dense Greater than 50
PERCENT OR PROPORTION OF SOILS PARTICLE SIZE
Description Criteria Description Size (In)
Trace Particles are present but estimated Boulder Greater than 12
to be less than 5% Cobble 3 -12
Few 5-10% Coarse 3/4 -3 Gravel Fine 1/5 -3/4 Little 15-25% Coarse 1/16-115
Some 30-45% Sand Medium 1/64 -1/16
Mostly 50 -100% Fine 1/300 -1/64
Silt and Clay Less than 1/300
CEMENTATION Plasticity
Description Criteria Description Criteria
Weak Crumbles or breaks with handling or Nonplastic A W -in. thread cannot be rolled at little finger pressure. any water content.
Moderate Crumbles or breaks with considerable
finger pressure. Low The thread can barely be rolled and
Strong Will not crumble or break with finger the lump cannot be formed when
pressure. drier than the plastic limit.
REFERENCE: Caltrans Soil and Rock Logging, Medium The thread is easy to roll and not
much time is required to reach the Classification, and Presentation Manual (2010), with plastic limit. The thread cannot be
the exception of consistency of cohesive soils vs. rerolle d after reaching the plastic
N50. limit. The lump crumbles when drier
than the plastic limit.
High It takes considerable time rolling
CONSISTENCY OF COHESIVE SOILS and kneading to reach the plastic
limit. The thread can be rerolled Description SPT N60 {blows/12 inches) several times after reaching the
Very Soft 0-2 plastic limit. The lump can be
formed without crumbling when
Soft 2 -4 drier than the plastic limit.
Medium Stiff 4-8
Stiff 8-1S
Very Stiff 15-30 Project No. S0589 Hard Greater than 30 GR□UP
Ref: Peck, Hansen, and Thornburn, 1974, .Jl 330 Chinquapin "FoundaUon Engineering,• Second Edition.
Noto: Only to bo usod (with caution) whon pockot ponotrometl!t' Carlsbad, CA 92008 or other data on undrained shear strength are unavailable. f'P--,~ Not allowed by C,ltrans SOil and Rock Logging and Oassific1tion Report of Geotechnical Investigation Manual, 2010. DELTA BORING RECORD LEGEND #3
BORING RECORD IPROJEC1 NAME I PROJECT NUMBER BORING
330 Chinquapin -Multi-Family Development SD589 B-01
SITE LOCATION I START !FINISH SHEET NO.
330 Chinauaoin Ave, Carlsbad, CA 10/10/2018 10/10/2018 1 of 1
DRILLING COMPANY DRILLING METHOD I LOGGED BY IC~ECKEDBY
Pacific Drilling Hollow Stem Auger TSL
DRILLING EQUIPMENT BORING DIA. (In) TOTAL DEPTH (ft) I GROUND ELEV (ft) I DEPTH/ELEY. GROUND WATER (ft)
Fraste 6 21.5 52 !'. N/A / na
SAMPLING METHOD NOTES
Hammer: 140 lbs., Drop: 30 in. (Automatic) ETR -83%, N60 -83/60 * N -1.38 * N
w zw ~ ~ ~ ~ z a. ci Ou~ w ~ ~ 0 ~ z i= z (D 0:: iii 0:: en ~ u ~<-i :i:C!> .=~ w t--en ~ ::::,~ ~'[ Wt--:I: ~Jl w ...J t--ens: ~c r. en :I: a.a DESCRIPTION AND CLASSIFICATION t--...J a. 1--W t--~...J a. w~ a. :l!: Wiiio 0 0 □-Qt--a. w ...J :l!: < ZW....1 ...J :l!: ~ w C!) Cl w < en w O::ai al Cl en a. -Cl
)~"),) .. ~SILTY SAND (SM); medium dense; red-brown; )) ) > .. ·. .__ ) ) -. : ..
dry to moist; mostly fine to medium SAND; little fines; ~>~ B-1 non-plastic. .__50 ~) ~ -·.: ·.·. :. :--l >
.__ X 4 14 -·. .. Orange-brown; fine SAND. S-2 5 10
.· ·. .__ ~ 5 -
~ .__ 5 .. ..
~ 8 .. .. Old Paranc Deposjts: Poorly-graded SAND with SILT R-3-1 27 25 .. .__ 11 3.2 ho6.a -. (SP-SM); medium dense; light orange-brown; moist; R-3-2 16 .. -.. mostly fine to medium SAND; few fines; non-plastic; .__45 . . -.. ·. · .. · .. weakly cemented.
. . .__ -... . . .. .__ ..
~10 .__ ~ 10 -::·: >.: .. _:.
S-4 8 20 28 '--9 ..
11 · . .. . . .
.__40 . . . ' . . .
..
.__ · . .. . . .
. • ..
-.. · . . . . . .
CD -15 -~ 15 .. .. .. -------------------------
~ 8 ... . . Poorly-graded SAND (SP); medium dense; light 27 25 ..
'--11 ..
I-R-5 16 4.1 99.9 yellow-brown; mostly fine to medium SAND; trace fines;
0 ·. ... friable. (!) .__35 .. (!) 0 .J .. u ..
0 -(!) .. .., .. . .. .. Q. (!) --. ,•.
(/) ..
(!) .. . .... 0 -20 -z 20-.. .J .. a, 9 . •'. CD "' S-6 21 29 0 -10 -· ..
(/) ....
0 11 "' I -30 .J -Total Depth -21 ½ feet. 5 "' I No Groundwater Encountered >< -::; ::;
(!) I -z a: 0 a, I (!)
1 GROUP DELTA CONSULTANTS, INC. THIS SUMMARY APPLIES ONLY AT THE LOCATION FIGURE 0 OF THIS BORING AND AT THE TIME OF DRILLING . .J
u 9245 Activity Road, Suite 103 SUBSURFACE CONDITIONS MAY DIFFER AT OTHER 0 LOCATIONS AND MAY CHANGE AT THIS LOCATION (!)
WITH THE PASSAGE OF TIME. THE DATA A-01 San Diego, CA 92126 PRESENTED IS A SIMPLIFICATION OF THE ACTUAL
CONDITIONS ENCOUNTERED.
BORING RECORD Ip ,I NAME I PROJECT NUMBER BORING
330 Chinquapin -Multi-Family Development SD589 B-02
SITE LOCATION
330 Chinquapin Ave, Carlsbad, CA
DRILLING COMPANY
Pacific Drilling
DRILLING EQUIPMENT
Fraste
SAMPLING METHOD
Hammer: 140 lbs., Drop: 30 in. (Automatic)
ti (!)
(!) g
(!)
~ (!)
ti)
:I: t w 0
1-5
-10
8,_20 .J
gi
"' 0 ti)
0 ti)
_,I
0 tl)I
X :::;; :::;;
(!)I z ii:
,__
,__
,__45
,__
,__
,__40
c--35
c--30
d z w ...J 0. !
►◄ R+1 ~R+2
u R-6-1 n R-6-2 -
4
6
6
6
6
7
11
20
23
5
8
9
14
19
21
12 17
13 18
43 40
17 24
40 37
I START !FINISH SHEET NO.
10/10/2018 10/10/2018 1 of 1
DRILLING METHOD I LOGGED BY !CHECKED BY
Hollow Stem Auger TSL o
BORING DIA. (In) TOTAL DEPTH (ft) I GROUND ELEV (ft) I DEPTH/ELEY. GROUND WATER (ft)
6 21.5 54 ~ N/A/ na
NOTES
ETR -83%, N00 -83/60 * N -1.38 * N
El
PA
Pl
6.7 ~14.1
.· ·. -....
.. ·.
.. · ·.
5 _ _. . '
-·
.. ' ..
·· .. · ..
-.
.. -...
10-. ·.·.
-
.. .. ..
-. . . ..
-·
. '
· .... . ' .. .. . . . -· ...
DESCRIPTION AND CLASSIFICATION
El.LL;. SIL TY SAND (SM); medium dense; red-brown;
moist; mostly fine to medium SAND; little fines;
non-plastic .
76% Sand; 24% Fines.
Old Paranc Deposits; Poorly-graded SAND with SILT
(SP-SM); dense; red-brown; moist; mostly fine to
medium SAND; few fines; non-plastic; weakly
cemented.
15 _,. ___ ~:_ .... · ... · --PoortY11raaeaSA'fJD(SJ:>T; meclium-aense;lightgray; ---
. ••, -....
.. -.. ·. ·. :_•.·.
-
. ••, .. .. ... ..
•'
20-......... :.-.:·:
...
-·._: ·. · .. :_-: ·.·
-
-
mostly fine to medium SAND (trace medium); trace
, fines; nonplastic; friable. _____________ ./.,..
Light yellow-brown; increase in medium SAND.
Total Depth -21½ feet.
No Groundwater Encountered
~--_._ __ ..._ ___ .__ __ ...__....._ __ ...__...__.....,.--.._ _ __... __ _._ ___________ .,... ________ --I
I g1 GROUP DELTA CONSULTANTS, INC.
§ 9245 Activity Road, Suite 103
San Diego, CA 92126
THIS SUMMARY APPLIES ONLY AT THE LOCATION
OF THIS BORING AND AT THE TIME OF DRILLING.
SUBSURFACE CONDITIONS MAY DIFFER AT OTHER
LOCATIONS AND MAY CHANGE AT THIS LOCATION
WITH THE PASSAGE OF TIME. THE DATA
PRESENTED IS A SIMPLIFICATION OF THE ACTUAL
CONDITIONS ENCOUNTERED.
FIGURE
A-02
BORING RECORD I PROJECT NAME I PROJECT NUMBER BORING
330 Chinquapin -Multi-Family Development SD589 B-03
SITE LOCATION
330 ChinauaDin Ave, Carlsbad, CA
DRIWNG COMPANY
Pacific Drilling
DRILLING EQUIPMENT
Fraste
SAMPLING METHOD
Hammer: 140 lbs., Drop: 30 in. (Automatic)
J: li:: w D
I--
1----50
I--
I--
~10 ~
00 -15 ;;
~
5 C!)
~ Cl C!)
~ C!)
Cl)
8 _20 ...J ~ "' Cl Cl)
Cl
Cl)'
...J 5 Cl) x' ::!! ::!!
C!>I z ii:
I--
I--
-
-
-
-35
-
-
-30
w a. ~ w _J a. !
d z w _J a. ~ Cl)
4
7
10
20
30
50
6
7
8
12
15
24
7
8
10
17 24
80 74
15 21
39 36
18 25
I START I FINISH SHEET NO.
10/10/2018 10/10/2018 1 of 1
DRILLING METHOD 'LOGGED BY 'CHECKED BY
Hollow Stem Auger TSL 0
BORING PIA. (In) TOTAL DEPTH (fl) I GROUND ELEV (fl) I DEPTH/ELEV. GROUND WATER (fl)
6 21.5 54 Y N/A/ na
NOTES
ETR -83%, N60 -83/60 * N -1.38 * N
a:cn WI-J: Cl) bl!:!
%200
CR
DS
%200
PA
%200
I
J:
li:: w D
-.
.. .. ·.
5 -· ..
.. -.. ..
-: •:'
· .... -: .. ·. .. . .
-. . .
10 -· ....
-.· .. · .. .. · .· ..
-.. : ..
-..... :· : · ..
..... -..
.. · .· ..
DESCRIPTION AND CLASSIFICATION
.El.LL:. SIL TY SAND (SM); loose; orange-brown; dry to
moist; mostly fine to medium SAND; little fines;
non-plastic.
17% Fines.
Medium dense.
Qld ParaHc Deposjts: Poorly-graded SAND with SILT
(SP-SM); medium dense; red-brown; dry to moist;
mostly fine to medium SAND; few fines; non-plastic;
weakly cemented.
Very dense; moderately cemented.
Strongly cemented.
Medium dense; light red-brown; moist; mostly fine to
medium SAND; few fines; nonplastic; friable .
9% Fines.
15 --+,-.,;..Ji-+.'-+---------------------------
-· ..
...
20 -r .. -·_..-_: l:
-
-
SIL TY SAND (SM); dense; orange-brown; moist; mostly
fine to medium SAND; little fines; non-plastic; weakly
cemented.
84% Sand; 16% Fines.
Poorly:graaeifSANo wlttislL T"(S'l'='~f; meaium-----
dense; orange-brown; moist; mostly fine to medium
SAND; little fines; non-plastic; friable.
7% Fines. ,r
Total Depth -21½ feet.
No Groundwater Encountered
alt-----'---+--+--.__ __ .._ _ __._ __ .___........__...._r--...._ _ ___. __ ......... ___________ -,--________ --1
§, GROUP DELTA CONSULTANTS, INC.
§ 9245 Activity Road, Suite 103
San Diego, CA 92126
THIS SUMMARY APPLIES ONLY AT THE LOCATION
OF THIS BORING AND AT THE TIME OF DRILLING.
SUBSURFACE CONDITIONS MAY DIFFER AT OTHER
LOCATIONS AND MAY CHANGE AT THIS LOCATION
WITH THE PASSAGE OF TIME. THE DATA
PRESENTED IS A SIMPLIFICATION OF THE ACTUAL
CONDITIONS ENCOUNTERED.
FIGURE
A-03
a,
~
I-Cl
(!)
(!) g
(.)
Cl (!)
a'. (!) en (!) g
"' a,
"' Cl en
Cl en
_J I
5 en
X I
::; ::;
(!) z ii:
I
BORING RECORD
SITE LOCATION
330 Chinauaoin Ave, Carlsbad, CA
DRILLING COMPANY
Pacific Drilling
DRILLING EQUIPMENT
Fraste
SAMPLING METHOD
Hammer: 140 lbs., Drop: 30 in. (Automatic)
:r: Ii:: w □
z w a. 0 ~ ~'-" ~jl w ...J w~ a. ...J ::; w <C VJ
zw~ ~ d ou;!; z ~z"' ~<C-i w I-VJ -;e ...J I-VJ s: a. ::; Wino 0 <C ZW...J ...J VJ WO::m ID a. -
I-
I-
><" > ..._ ?). ?). ?). y') ><" >>,. '10 ..._ ❖ .J'x y')
B-1
t-..._ X -50 ~ ..._
S-2 8 28 39 12
16
I-..._ X S-3 17 35 48 18
17 -
-
-45
>-10 ..._
I-..._
t--
I-..._
I-..._40
>-15 ..._
t-..._
-
-
-35
-20 ..._
-
-
-
-30
I PROJECT NAME I PROJECT NUMBER BORING
330 Chinquapin -Multi-Family Development S0589 8-04
I ST ART I FINISH SHEET NO.
10/10/2018 10/10/2018 1 of 1
DRILLING METHOD I LOGGED BY !CHECKED BY
Hollow Stem Auger TSL o
BORING DIA. (In) TOTAL DEPTH (ft) I GROUND ELEV (ft) I DEPTH/ELEII. GROUND WATER (ft)
6 6.5 54 !'. NIA/ na
NOTES
ETR -83%, N60 -83/60 * N -1.38 * N
w ~ a: 0:: VJ VJ :::J~ zc WI-ti;~ w I.) :r: VJ o.e 1-W 0 01->-::; 0:: □
R
~ ~ :r: I-D.. w □
-.
(.)
:i:C!l a.a
~...J
C!)
.. .. ,•
'• ..
--: : ·. ·. : .
-
-· ... ·.
5 -. · ..
-: . : .
-
10-
-
-
-
15 -
-
20 -
DESCRIPTION AND CLASSIFICATION
fl.LL;, SIL TY SAND (SM); loose; orange-brown; dry to
moist; mostly fine to medium SAND; little fines;
non-plastic.
Medium dense; red-brown.
"" .. ,.,., ... ,., . Poorly-graded SAND With ::ilL T
(SP-SM); dense; red-brown; moist; mostly fine to
medium SAND; few fines; non-plastic; weakly
cemented.
Moderately cemented.
Total Depth -6½ feet.
No Groundwater Encountered
0 ai,t-----'---"---l-----"'----"---......... ----.__ _ _.__.._,_..___ ......... __ ....._ ___________ "'T""" ________ ....
Cl THIS SUMMARY APPLIES ONLY AT THE LOCATION gl GROUP DELTA CONSULTANTS, INC. OFTHISBORINGANDATTHETIMEOFDRILLING.
u SUBSURFACE CONDITIONS MAY DIFFER AT OTHER g 9245 Activity Road, Suite 103 LocAT1ONsAND MAvcHANGEATTH1s LocAT1ON WITH THE PASSAGE OF TIME. THE DATA
San D·1ego, CA 92126 PREsENTED1sAs1MPuF1cAT1ONoFTHEAcTuAL
CONDITIONS ENCOUNTERED.
FIGURE
A-04
BORING RECORD I PROJECT NAME I PROJECT NUMBER BORING
330 Chinquapin -Multi-Family Development S0589 8-05
SITE LOCATION I START !FINISH SHEET NO.
330 ChinQuapin Ave, Carlsbad, CA 10/10/2018 10/10/2018 1 of 1
DRILLING COMPANY DRILLING METHOD I LOGGED BY IC~ECKEDBY
Pacific Drilling Hollow Stem Auger TSL
DRILLING EQUIPMENT BORING DIA. (In) TOTAL DEPTH (ft) I GROUND ELEV (ft) I DEPTH/EL.Ev. GROUND WATER (ft)
Fraste 6 21.5 54 ~ N/A / na
SAMPLING METHOD NOTES
Hammer: 140 lbs., Drop: 30 in. (Automatic) ETR -83%, N60 -83/60 * N -1.38 * N
w zw~ ~ ~ z a. ci Ou~ w ~ ~ ~ 0 ~ z f'.=Z co c:: c:: (/) ~ CJ f'.=,;::-~<-t;: (/) :i:C!> w I-(/) ~ =>~ zu WI-:i:: ~j w ...J ~ ti~ :i:: (/) :i:: a.a DESCRIPTION AND CLASSIFICATION I-...J a. 1-(/):S: w C. 1-W Ii:: ~...J a. w~ a. :::; Wino 0 5 Cl-01-w ...J :::; < Zw...J ...J >-w (!) Cl w < (/) WC::ai III :::; c:: Cl
(/) a. -Cl
::,.,. ..
~ ..
><'>c ><'>c
.· • .. ·_. ~SILTY SAND (SM); loose; red-brown; dry to -~ moist; mostly fine to medium SAND; little fines; )) B-1 %200
><'>c .,:> El ·. .. ... non-plastic. ->9 -?x .. 17% Fines. Y') ,, . . Medium dense .
-~ 11 75 69 R-2-1 25 . ,• :f ,__50 R-2-2 50 DS : . : Old parajjc Deposjts· Poorly-graded SAND with SILT
~ .. (SP-SM); very dense; red-brown; dry to moist; mostly
.. ... fine to medium SAND; few fines; non-plastic; moderately µ -5 -· ... cemented, pieces strongly cemented.
22 ..
.... 1--S.3 19 34 47 . . Orange-brown; weakly cemented . ·. ...
15 ..
1--.. . . . . . -.. ·.
-45 .. . .
,•
-10 -8 10-', . . . Light green/orange-brown. 10 ..
R-4-1 34 31 .. -15 114.1
..
R-4-2 19 4.7 '• ·. ... ..
~ -. . · . .... . .
.... 1--. ,
..
o--40 .. .. · . . .
a, t-15 1--X 15 -..
~ 5 ·. . . . .
S.5 12 17 %200 . . 7% Fines . -5 ·.
I-7 0 .. Light brown; increase in medium SAND; not cemented. <!) · . . . . ci -..
0 . , .. 13 ...
0 1--.. <!)
~ ..
<!) -35 ..
c,j . . .
<!) .. 0 -20 -~ 20 PoorlKJracfecfSAND(SPT; meclium dense;l@,tgray;---_J ..
a, 10 . .
a, R-6-1 29 27 .·.· ·.·.·. moist; mostly medium SAND; trace fines; nonplastic; "' 0 -12 . . friable . en 100.2 R-6-2 17 3.9 ..
0 -Very light yellow-brown; fine to medium SAND. / en
_J I -
0 Total Depth-21½feet. en I >< -No Groundwater Encountered ~ ~
<!) I -30 z 1i: 0 ID I THIS SUMMARY APPLIES ONLY AT THE LOCATION <!)
1 GROUP DELTA CONSULTANTS, INC. FIGURE 0 OF THIS BORING AND AT THE TIME OF DRILLING. _J
u 9245 Activity Road, Suite 103 SUBSURFACE CONDITIONS MAY DIFFER AT OTHER 0 LOCATIONS AND MAY CHANGE AT THIS LOCATION <!)
WITH THE PASSAGE OF TIME. THE DATA A-05 San Diego, CA 92126 PRESENTED IS A SIMPLIFICATION OF THE ACTUAL
CONDITIONS ENCOUNTERED.
BORING RECORD
SITE LOCATION
330 Chinquapin Ave, Carlsbad, CA
.,
ai s
,-0 (!)
ci 0 d 0 (!)
~ (!) z 0
DRILLING COMPANY
Hand Digging
DRILLING EQUIPMENT
Hand Auger
SAMPLING METHOD
I-'ii' z Cl) _J ~ 0 w <( j::: z:-~~ :r: ~Jl I-_J w Cl. w~ Cl. I-w _J :l!:z 0 w <(-
Cl)
1 -53
2 -52
3 -51
4 -50 \v
~ -49 I I\ -~
~ 6 -48
ii: ~
0 ~
ffi e> 7 ,---47 ~
0 ~
(/)
8 8 ,---46 .J
~ 0 (/)
0 "', .J 5 (/) I ~ :::;; I (!) z ii: 0 Ill I
9 ,---45
z zw-~ 0 Ou~
j::: j::: z"' i Cl. ~<-i'2 I-Cl)
u Iii !Q :!: zCIJO 0 Cl) w~-' _J w aJ 0 Cl. ~
~
;e
I PROJECT NAME I PROJECT NUMBER BORING
330 Chinquapin -Multi-Family Development SD589 1-01
NOTES
w a::
::J-~c 0 :l!:
DRILLING METHOD
Hand Auger
BORING DIA. (In)
6
~ 'ii'
Cl) a:: Cl) ~ ~'R WI-:r: Cl) :r:
0-1-W Ii: ~ 01-w 0 0
1 -.
I START 'FINISH SHEET NO.
10/10/2018 10/10/2018 1 of 1
I LOGGED BY 'CHECKED BY
TSL
TOTAL DEPTH (ft) I GROUND ELEV (ft) I DEPTH/ELEY. GROUND WATER (ft)
4.9 54 f: N/A / na
u
i:(!) Cl.a
~_J
(!)
..
. .
..
. . ..
DESCRIPTION AND CLASSIFICATION
.El.LL;. SIL TY SAND (SM); medium dense;
orange-brown; dry to moist; mostly fine to medium
SAND; little fines; non-plastic .
2 -: .
3
4 -
PA
5 -
6 -
7 -
8
9
..
..
. . ·.
Old ParaUc Deposits: SIL TY SAND (SM); medium
dense; light orange-brown; moist; mostly fine to medium
SAND; little fines; non-plastic .
83% Sand; 17% Fines .
Total Depth -4.9 feet.
No Groundwater Encountered
§, GROUP DELTA CONSULTANTS, INC. THIS SUMMARY APPLIES ONLY AT THE LOCATION
OF THIS BORING AND AT THE TIME OF DRILLING.
SUBSURFACE CONDITIONS MAY DIFFER AT OTHER
LOCATIONS AND MAY CHANGE AT THIS LOCATION
WITH THE PASSAGE OF TIME. THE DATA
PRESENTED IS A SIMPLIFICATION OF THE ACTUAL
CONDITIONS ENCOUNTERED.
FIGURE
A-06 g 9245 Activity Road, Suite 103
San Diego, CA 92126
GROUPCELTA
APPEND/XS
GEOTECHNICAL LABORATORY TESTING
LABORATORY TESTING
laboratory testing was conducted in a manner consistent with the level of care and skill ordinarily
exercised by members of the profession currently practicing under similar conditions and in the same
locality. No warranty, express or implied, is made as to the correctness or serviceability of the test
results, or the conclusions derived from these tests. Where a specific laboratory test method has been
referenced, such as ASTM or Caltrans, the reference only applies to the specified laboratory test
method, which has been used only as a guidance document for the general performance of the test
and not as a "Test Standard". A brief description of the various tests performed for this project follows.
Classification: Soils were visually classified according to the Unified -Soil Classification System as
established by the American Society of Civil Engineers per ASTM D2487. The soil classifications are
shown on the boring logs in Appendix A.
Percent Passing #200/Particle Size Analysis: Particle size analyses were performed in accordance with
ASTM D1140 and ASTM D422, and were used to supplement visual classifications. The results are
shown in Appendix A on the boring logs, and Particle Size Analysis results are shown in Figures 8-1.1 to
8-1.3.
Atterberg Limits: ASTM D4318 was used to determine the liquid limit and plasticity index of selected
samples. The results are shown in Appendix A on the boring logs.
Expansion Index: The expansion potentials of selected samples of finish grade soils within the building
pad areas were estimated in general accordance with the laboratory procedures outlined in ASTM test
method D4829. The test results are summarized in Figure 8-2.
pH and Resistivity: To assess the potential for reactivity with buried metals, selected soil samples were
tested for pH and minimum resistivity using Caltrans test method 643. The corrosivity test results are
summarized in Figure 8-3.
Sulfate Content: To assess the potential for reactivity with concrete, selected soil samples were tested
for water soluble sulfate. The sulfate was extracted from the soil under vacuum using a 10:1 (water to
dry soil) dilution ratio. The extracted solution was tested for water soluble sulfate in general
accordance with ASTM D516. The test results are also presented in Figure 8-3, along with common
criteria for evaluating soluble sulfate content.
Chloride Content: Soil samples were also tested for water soluble chloride. The chloride was extracted
from the soil under vacuum using a 10:1 (water to dry soil) dilution ratio. The extracted solution was
then tested for water soluble chloride using a calibrated ion specific electronic probe. The test results
are also shown in Figure 8-3.
R-Value: An R-Value test was performed on selected samples of the on-site soils in general accordance
with CTM 301. The test results are shown in Figure 8-4.
Direct Shear: The shear strength of selected samples of the on-site soil was assessed using direct shear
testing performed in general accordance with ASTM D3080. The test results are shown in Figures 8-5.1
and 8-5.2.
t}· GR□LFDELT.A
100
90
80
E .2> 70 ~
~ 60
lii C: u: c ~ (I)
Cl.
50
40
30
20
10
0
100
" 1..4"
COARSE
GRAVEL
SAMPLE
BORING NUMBER: B-2
SAMPLE DEPTH: 2.5' -4'
,. .. "
-0% Gravel
10
FINE
U.S. Standard Sieve Sizes
"' ",n '"" ,n '"n .,,nn . n -~7 ' I ' \ I
I ' I
: \ I
\ I
'"'
' \ I
' \ I
\ ' :
I \
' \ ' "-. 33 I
' .... ~ --
76%Sand +-+ 24% Fines-+
0.1
Grain Size in Millimeters
COARSE MEDIUM FINE
SAND
UNIFIED SOIL CLASSIFICATION: SM
DESCRIPTION: SIL TY SAND
GR□UPDELTA SOIL CLASSIFICATION
L...1.7
0.01
SILT AND
CLAY
,~
0.001
ATTERBERG LIMITS
LIQUID LIMIT: -
PLASTIC LIMIT: -
PLASTICITY INDEX: -
Project No. SD589
Document No. 18-0136
FIGURE B-1.1
100
90
80
E f 70
l, 60
ai C u::
C: ~ Q) a.
50
40
30
20
10
0
100
1" 1,(," , ...
COARSE
GRAVEL
SAMPLE
BORING NUMBER: 8-3
SAMPLE DEPTH: 16'-16½'
-0% Gravel
10
FINE
U.S. Standard Sieve Sizes
d "" ""' _.,,n .. ,.. """' "
I \ 1'+
'
\ '
' \ ' ' I
' \
' ' 53 ' 1! \
! \
' \ ' I '\
' \.. ' I 'V
' ' ~ I"
I
I ' ' 84% Sand +-+ I 16% Fines-+ '
0.1
Grain Size in Millimeters
COARSE MEDIUM FINE
SAND
UNIFIED SOIL CLASSIFICATION: SM
DESCRIPTION: SIL TY SAND
GR□UP DEL TA SOIL CLASSIFICATION
0.01
SILT AND
CLAY
0.001
ATTERBERG LIMITS
LIQUID LIMIT: -
PLASTIC LIMIT: -
PLASTICITY INDEX: -
Project No. SO589
Document No. 18-0136
FIGURE B-1.2
100
90
80
1:
-~ 70
~
~ 60 .... Q)
C u: c ~ Q) Q.
50
40
30
20
10
0
100
3" ½"
COARSE
GRAVEL
SAMPLE
BORING NUMBER: 1-1
SAMPLE DEPTH: 4'-5'
Id""
U.S. Standard Sieve Sizes ,,, . '4 #8 ""' ... .,, "'"' #100 • ...,
' ) "' ' I \
'
' ' \
' ' ' I \
' ' \
' ' I
l "" I
I \
I \ I
' I \ '
' I ' I \
I \. ~~ t
I "-
11 7
' ' I
I +-0°.4 Gravel i 83% Sand +-+ 17% Fines-
10 0.1
Grain Size in Millimeters
FINE COARSE MEDIUM FINE
SAND
UNIFIED SOIL CLASSIFICATION: SM
DESCRIPTION: SIL TY SAND
GR.CUP DEL TA SOIL CLASSIFICATION
0.01
SILT AND
CLAY
0.001
ATTERBERG LIMITS
LIQUID LIMIT: -
PLASTIC LIMIT: -
PLASTICITY INDEX: -
Project No. SD589
Document No. 18-0136
FIGURE 8-1.3
Sample
Number
EXPANSION INDEX
(ASTM D4829)
Soil Description
FILL: Red-Brown Silty Sand (SM)
Expansion
Index
B-2@0'-5'
B-5 @0'-5' FILL/Formation Blend: Red-Brown Silty Sand/ Poorly-graded Sand with Silt (SM/SP-SM)
0
0
Expansion Index
Oto20
21 to 50
51 to 90
91 to 130
Above 130
A GROUP DELTA
Potential Expansion
Very Low
Low
Medium
High
Very High
LABORATORY TEST RESULTS
Project No. SD589
Document No. SDlS-0136
Figure B-2
Sample
Number
B-3@0'-5'
pH
7.58
SULFATE CONTENT[%]
O.OOto 0.10
O.lOto 0.20
0.20to 2.00
Above2.00
SOIL RESISTIVITY
Oto 1,000
1,000 to 2,000
2,000 to 5,000
5,000 to 10,000
Above 10,000
CHLORIDE (Cl) CONTENT[%]
O.OOto 0.03
0.03 to 0.15
Above 0.15
~GRCUPDELT.A
CORROSIVITY
{ASTM 0516, CTM 643}
RESISTIVITY
[OHM-CM]
SULFATE CONTENT
[%]
CHLORIDE CONTENT
7075
SULFATE EXPOSURE
Negligible
Moderate
Severe
Very Severe
0.01 <0.01
CEMENT TYPE
II, IP(MS), IS(MS)
V
V plus pozzolan
GENERAL DEGREE OF CORROSIVITY TO FERROUS METALS
Very Corrosive
Corrosive
Moderately Corrosive
Mildly Corrosive
Slightly Corrosive
GENERAL DEGREE OF CORROSIVITY TO METALS
Negligible
Corrosive
Severly Corrosive
LABORATORY TEST RESULTS
Project No. SD589
Document No. SDlB-0136
Figure B-3
Sample
Number
B-4@ 0'-5'
Location of Sample
Proposed Drive/Parking Area
R-VALUE
(CTM 301)
Sample Description
FILL: Orange-Brown Silty Sand (SM)
R-Value
70
GR□UPDELTA LABORATORY TEST RESULTS
Project No. SD589
Document No. SDlS-0136
Figure 8-4
4000
Ii:'
[ 3000
Cl)
Cl)
~ 2000 .... Cl)
0::
j'.5 1000
J: Cl)
0
0.0
Ii:'
Cl) e:.
Cl)
Cl)
4000
3000
~ 2000 ....
Cl)
0:: < w J: Cl)
1000
0
2.0
0
4.0
STRAIN[%]
■ Peak Strength Test Results
--38 Degrees, 300 PSF Cohesion
• Ultimate Strength Test Results
--38 Degrees, 50 PSF Cohesion
1000 2000
6.0
3000
NORMAL STRESS [PSF]
SAMPLE: B-3 @ 6' -6.5' PEAK
Descri~tion: ♦' 38 °
Poorl}'-Graded Sand with Silt (SP-SM) C' 300 PSF
STRAIN RA TE: I 0.0030 IN/MIN I IN-SITU
'Y. 106.6 PCF
(Sample was consolidated and drained) w. 3.0 %
GR.CUP DEL T .A DIRECT SHEAR TEST RESULTS
I
8.0 10.0
4000
ULTIMATE
I 38 °
50 PSF
AS-TESTED
106.6 PCF
18.1 %
Project No. SD589
Document No. 18-0136
FIGURE B-5.1
4000
~ ~ 3000
en en w a:: 2000 I-C/)
a:: ~ 1000
J: en
0
0.0
~ en a.. ..... en en
4000
3000
w 2000 a:: I-C/)
a:: <( w J: en
1000
0
2.0
0
SAMPLE: 8-5 @ 3.5' -4'
4.0
STRAIN[%]
■ Peak Strength Test Results
--43 Degrees, 0 PSF Cohesion
♦ Ultimate Strength Test Results
--42 Degrees, O PSF Cohesion
6.0
1000 2000 3000
NORMAL STRESS [PSF]
PEAK
8.0 10.0
4000
ULTIMATE
Descrif;!tion: ♦' 43 °
Poorlv-Graded Sand with Silt (SP-SM) C' 0 PSF ..__ __ ___._ ___ ___.I l..___
4
....;~-~-S'-F---'
IN-SITU
STRAIN RATE: I 0.0030 IN/MIN I r. I 106.9 PCF
(Sample was consolidated and drained) Ws 2.9 %
~~~ GR□UP DEL T .A. DIRECT SHEAR TEST RESULTS
AS-TESTED
106.9 PCF
19.0 %
Project No. SD589
Document No. 18-0136
FIGURE B-5.2
~GR□UPDELTA
APPENDIXC
STORM WATER INFILTRATION ASSESSMENT
INFILTRATION TESTING
Each proposed storm water infiltration BMP requires exploratory borings and in situ testing to
justify an infiltration recommendation. During the planning phase, City of Carlsbad, BMP Design
Manual dated February 16, 2016 (referred to hereon as Design Manual) recommends a feasibility
screening to assess the site conditions and potential for infiltration. Our investigation included test
borings at least ten feet below the potential BMP elevations, and one infiltration test to assess
preliminary infiltration rates.
The results of our field tests are shown in Figures C-1.1 and C-1.2. The test results are considered
preliminary and are not based on a specific site plan. Our preliminary conclusions about storm
water infiltration BMPs, based on the requirements of the Design Manual, are attached in the
completed Worksheet 1-8. The factor of safety applied for planning phase feasibility screening is 2.5
and shown attached in the completed Worksheet /-9.
The Borehole Percolation Test was used to help approximate infiltration rates of the soils near the
proposed infiltration zones. The test was set up by excavating a six-inch diameter test hole using a
hand-operated power auger (Appendix A). The hole was cleaned of loose material down to the
desired test depth. Perforated PVC casing was placed in the open hole. Open-graded gravel was
used to fill the annular space between the casing and the sidewalls of the test hole to support the
sidewalls of the test hole and prevent sloughing during saturation of the soil. Each hole was pre-
soaked prior to testing to more closely model saturated conditions and to achieve a stabilized
percolation rate.
The Borehole Percolation Test requires the hole to be filled with water to the test depth and the
rate of fall of water (percolation rate) to be measured periodically. To measure the percolation
rate, the drop of water in the hole (t.H) is measured at regular time intervals (fit). After each
reading, or a number of readings, when the water column has measurably dropped from the
desired test depth, water is added to the hole to maintain a relatively constant column of water in
the test hole (Havg).
During the test, water percolates into the surrounding ground both horizontally through the side
walls of the hole and vertically through the bottom of the hole. To more accurately approximate
the desired vertical infiltration rate {It), the percolation rate is modified mathematically. The Design
Manual recommends using a formula called the simplified Porchet method, shown below in
Equation 1.
The simplified Porchet method assumes an open hole is used to measure the percolation rate
(t.H/tit). Our hole was cased with perforated PVC pipe and gravel to stabilize the hole. The
measured drop in water (t.H) is amplified by the fact that some space in the hole was occupied by
gravel, and not water. To account for this, the corrected drop in water (f.Hc) is calculated by
reducing the measured drop in water by the ratio of the area of the hole occupied by water to the
total area of the hole. The porosity of the gravel was assumed to be 0.4 based on laboratory
testing of similar gravel.
,;\ ~ GRDJP DELTA
The percolation rate, and in turn, the infiltration rate, generated from the field tests are
dependent on the head pressure present during the tests. The percolation tests were run with
approximately 13 inches of water (head pressure, Havg), as shown in Figure C-1.1. If the BMP is
designed to accommodate significantly different head pressures, the infiltration rate provided
based on these field tests may not be applicable.
Equation 1 (simplified Porchet method):
Where:
t~ GROUP CEL TA
11 = tested infiltration rate, inches/hour
6H = change in head over the time interval, inches
61 = time interval, minutes
•r = effective radius oftest hole
Ha,s = average head over the time interval, inches
BOREHOLE PERCOLATION TEST
Data Sheet
Project Name: 330 Chinquapin -Multi Family Residence Date Drilled: 10/10/2018
Project Number: S0589 logged By: TSL
Test Hole No: 1-1 Date Tested: 10/11/2018
Drilling Method: Hand Auger Tested By: TSL
Average Head Measured Time Initial Final Depth of
Reading Interval Depth of Water of Water Drop in Water
Number Level (min.) Water (ft.) (ft,) (in.) (in.)
-------------------------------------------------------------------------------------
At H•vs AH
Pre-Soak 100 3.00 ------
Pre-Soak 14 (<25) 3.48 4.30 12.12 9.84
Pre-Soak 13 (<25) 3.39 4.20 13.26 9.72
1 10 3.51 4.12 13.02 7.32
2 10 3.55 4.14 12.66 7.08
3 10 3.48 4.10 13.32 7.44
4 10 3.48 4.11 13.26 7.56
5 10 3.50 4.12 13.08 7.44
6 10 3.53 4.11 12.96 6.96
7 10 3.53 4.09 13.08 6.72
8 10 3.54 4.09 13.02 6.60
9 10 3.44 4.04 13.92 7.20
Borehole Radius (*r): 3 in.
Depth of Hole as Drilled: 4.9 ft
Depth of Hole as Tested: 4.9 ft
Test Depth: 3.5' -5.1'
Corrected Corrected Measured
Drop in Water Percolation Infiltration
Level1 Rate1 Rate2
(in.) (in./hour) (in./hour) ------------------------------------------AHc AHJAt 1,
------
6.56 28.11 3.10
6.48 29.91 3.04
4.88 29.28 3.02
4.72 28.32 3.00
4.96 29.76 3.01
5.04 30.24 3.07
4.96 29.76 3.06
4.64 27.84 2.89
4.48 26.88 2.77
4.40 26.40 2.73
4.80 28.80 2.80
Stabilized
1: Porosity of gravel assumed to be 0.4 to correct drop In water. See text of Appendix C for details. 2 Infiltration Rate . 2.76 inch/hour 2: Porchet method used to convert percolation rate to Infiltration rate. See text of Appendix C for .
details.
1}]~ Project No. S0589
1.W□UP DELT~ 1-1 Document No. 18-0136
~P •~ FIGURE C-1.1
3.5
3.25
CII ~ 2.5
C ~ 2.25 .s c;:: 2 = ,,
~ 1.75 ~
tf. 1.5
1.25
1
0 10
BOREHOLE PERCOLATION TEST
Measured Infiltration Rates During Test
___.._, Measured Infiltration Rat•Z
(lnJhou,)
• • • • • • • • • Averace lnfittration Rate: 2.76 Jn./hour
20 30 40 so 60 70 80
Duration of Test (minutes)
Preliminary Factored Infiltration Rate: 1.1 in./hr.
Feasibility Screening Factor of Safety, F.S. * = 2.5
Factored Infiltration Rate* Design Condition*
Below0.05 No Infiltration
0.05 to 0.5 Partial Infiltration
Above 0.50 Full Infiltration
"Reference: The City of Carlsbad, BMP Design Manual (2016).
90
L:iRCJUP DEL Ti\ 1-1
Project No. SD589
Document No. 18-0136
FIGURE C-1.2
Appendix I: Forms and Checklists
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.
Yes
Provide basis:
Results should be confirmed or revised, as necessary, based on more detailed design-level
investigation and analysis during BMP design.
See Section "Storm Water Infiltration" of this report (Group Delta Consultants -Report of
Geotechnical Investigation, 330 Chinquapin Avenue, dated November 15, 2018).
No
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability.
2
Can infiltration greater than 0.5 inches per hour be allowed
without increasing risk of geotechnical hazards (slope stability,
groundwater mounding, utilities, or other factors) that cannot
be mitigated to an acceptable level? The response to this
Screening Question shall be based on a comprehensive evaluation of
the factors presented in Appendix C.2.
Provide basis:
Results should be confirmed or revised, as necessary, based on more detailed design-level
investigation and analysis during BMP design.
See Section "Storm Water Infiltration" of this report (Group Delta Consultants -Report of
Geotechnical Investigation, 330 Chinquapin Avenue, dated November 15, 2018).
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability.
1-3 February 2016
Criteri
a
3
Appendix I: Forms and Checklists
~ : ~ . .
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.
Yes No
Provide basis:
Results should be confirmed or revised, as necessary, based on more detailed design-level
investigation and analysis during BMP design.
See Section "Storm Water Infiltration" of this report (Group Delta Consultants -Report of
Geotechnical Investigation, 330 Chinquapin Avenue, dated November 15, 2018).
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability.
4
Can infiltration greater than 0.5 inches per hour be allowed
without causing potential water balance issues such as change
of seasonality of ephemeral streams or increased discharge of
contaminated groundwater to surface waters? The response to
this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
Provide basis:
Results should be confirmed or revised, as necessary, based on more detailed design-level
investigation and analysis during BMP design.
See Section "Storm Water Infiltration" of this report (Group Delta Consultants -Report of
Geotechnical Investigation, 330 Chinquapin Avenue, dated November 15, 2018).
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability.
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
YES
*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 to substantiate findings.
1-4 February 2016
Appendix I: Forms and Checklists
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 Appendix C.2 and Appendix D.
Provide basis:
Yes No
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates.
6
Can Infiltration in any appreciable quantity be allowed
without increasing risk of geotechnical hazards ( slope
stability, groundwater mounding, utilities, or other factors)
that cannot be mitigated to an acceptable level? The response
to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.2.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates.
1-5 February 2016
Appendix I: Forms and Checklists
Criteria
7
ii'mm ... _
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
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates.
8
Can infiltration be allowed without violating downstream
water rights? The response to this Screening Question shall be
based on a comprehensive evaluation of the factors presented in
Appendix C.3.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates.
Part2
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.
*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 to substantiate findings.
1-6 February 2016
Appendix I: Forms and Checklists
-.... ,Ii: .. -... .,:-; •-•IU'WJl."1 . . , • ,:.. ... u~nlmnu.,...111111 • . ... -w:, . .:'.--:' ...... • '
Factor Category Factor Description Assigned Factor Product (p)
Weight (w) Value (v) p =wxv
Soil assessment methods 0.25 2 0.5
Predominant soil texture 0.25 1 0.25
Suitability Site soil variability 0.25 1 0.25 A Assessment Depth to groundwater I impervious
layer 0.25 1 0.25
Suitability Assessment Safety Factor, SA = :Ep 1.25
Level of pretreatment/ expected 0.5 sediment loads 2 1
B Design Redundancy/ resiliency 0.25 2 0.5
Compaction during construction 0.25 2 0.5
Design Safety Factor, Sa = :Ep 2
Combined Safety Factor, S,0121= SA x Sa 2.5
Observed Infiltration Rate, inch/hr, Kobscrvcd
(corrected for test-specific bias) 2.76
Design Infiltration Rate, in/hr, K.icsign = Kob,ervcd / S,0121 1.1
Supporting Data
Briefly describe infiltration test and provide reference to test forms:
See Section "Storm Water Infiltration" of this report (Group Delta Consultants -Report of
Geotechnical Investigation, 330 Chinquapin Avenue, dated November 15, 2018).
1-7 February 2016