HomeMy WebLinkAboutCT 00-19; Carlsbad Promenade; Tentative Map (CT) (5)^un=^ Leighton and Associates
A GTG Company GEOTECHNICAL CONSULTANTS
GEOTECHNICAL INVESTIGATION
PROPOSED RESIDENTIAL DEVELOPMENT,
POINSETTIA LANE AT ARIZONA PARKWAY,
CARLSBAD, CALIFORNIA
Febniary 13, 1998
(Revised November 29, 1999)
ProjectNo. 4980005-002
Prepared For:
KOLL Real Estate Group
4275 Executive Square, Suite 240
La Jolla, Califomia 92037
3934 Murphy Canyon Road, #8205, San Diego, CA 9213-4425
(619) 292-8030 • FAX (619) 292-0771 • www.leightongeo.com
^""f^ Leigtiton and Associates
A GTG Company GEOTECHNICAL CONSULTANTS
February 13, 1998
(Revised November 29, 1999)
ProjectNo. 4980005-002
To: KOLL Real Estate Group
4275 Executive Square, Suite 240
La Jolla, Califomia 92037
Attention: Mr. Tony Badeaux
Subject: Geotechnical Investigation, Proposed Residential Development, Poinsettia Lane at Aviara
Parkway, Carlsbad, Califomia.
In accordance with your request, we have perfonned a geotechnical investigation for the residentiai project
located at the northeast comer of Poinsettia Avenue and Aviara Parkway in Carlsbad, Califomia (see Site
Location Map, Figure 1, Page 2). The purpose of our study was to review the current site conditions and
evaluate the geologic conditions with regard to future site development. This report presents our results of
our geotechnical investigation of the site. Our geotechnical analysis conclusions and our recommendations
relative to the proposed development are presented herein.
Based on the results of our investigation and review of previous reports pertinent to the subject site, the
proposed development is considered feasible from a geotechnical standpoint provided the recommendations
outlined in this report are implemented during grading and constmction.
If you have any questions regarding our report, please contact this office. We appreciate this opportunity to
be of service.
Respectfully submitted,
LEIGHTON AND ASSOCIATES, INC.
i Michael R. StewH-CEG 1349 (Exp. 1
Director of Geology
MRS/JGF
Distribution: (6) Addressee
Franzone, RC
of Engineering
3934 Murphy Canyon Road, #B205, San Diego, CA 9213-4425
(619) 292-8030 • FAX (619) 292-0771 • www.lelghtongeo.com
4980005-002
TABLE OF CONTENTS
Section Page
LO INTRODUCTION 1
1.1 PURPOSE AND SCOPE 1
1.2 SITE DESCRIPTION 1
1.3 PREVIOUS SITE GRADING 2
1.4 PROPOSED DEVELOPMENT 2
2.0 SUBSURFACE INVESTIGATION 4
2.1 FIELD INVESTIGATION 4
2.2 LABORATORY TESTING 4
2.3 REGIONAL GEOLOGY 4
3.0 SUMMARY OF GEOTECHNICAL CONDITIONS 5
3.1 SITE GEOLOGY 5
3.1.1 Undocumented Fill Soils (Map symbol - Afa) 5
3.1.2 Documented Fill Soils (Map Symbol -Afd) 5
3.1.3 Documented Fill Soils (Map Symbol- Afo) 6
3.1.4 Topsoil/CoUuvium (Map Symbol - Qcol) 6
3.1.5 Quaternary Alluvium (Map Symbol - Qal) 6
3.1.6 Quaternary Terrace Deposits (Map Symbol -Qt) 6
3.1.7 Tertiary Scripps Formation (Map Symbol - Tsc) 7
3.2 GEOLOGIC STRUCTURE 7
3.3 GROUNDWATER 7
3.4 FAULTING AND SEISMICITY 8
3.5 SEISMICITY 8
3.5.1 Shallow Ground Rupture 10
3.5.2 Liquefaction and Dynamic Settlement 10
3.5.3 Tsunamis and Seiches 10
4.0 CONCLUSIONS 11
5.0 RECOMMENDATIONS 13
5.1 EARTHWORK 13
5.1.1 Site Preparation 13
5.1.2 Removal and Recompaction of Potentially Compressible Soils 13
5.1.3 Excavations 14
5.1.4 Fill Placement and Compaction 14
5.2 TRANSITION LOTS 14
5.3 FOUNDATION DESIGN 15
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TABLE OF CONTENTS (Continued)
5.3.1 Conventionally Reinforced Foundation System -Lo-wto Medium Expansion Soils 15
5.3.2 Post-Tension Foundation Design (Very Lo'w to liighly Expansive Soils) / 7
5.3.3 Moisture Conditioning 18
5.4 ANTICIPATED SETTLEMENT 19
5.5 RETAINING WALL DESIGN CONSIDERATIONS 20
5.6 FOUNDATION SETBACKS 21
5.7 TYPE OF CEMENT FOR CONSTRUCTION 21
5.8 CORROSION RESISTANCE 21
5.9 SLOPE STABILITY 22
5.10 PRELIMINARY PAVEMENT DESIGN 22
5.11 GRADED SLOPES 23
6.0 CONSTRUCTION OBSERVATION 24
Figure
Figure 1 - Site Location Map - Page 3
Tables
Table 1 - Seismic Parameters - Page 9
Table 2 - Minimum Foundation Slab Design Recommendations - Page 16
Table 3 - Post-Tensioned Foundation Design Recommendations for Expansive Soils - Page 17
Table 4 - Minimum Presaturation Recommendations for Foundation Subgrade Soils - Page 19
Plate
Plate 1 - Geotechnical Map In Pocket
Appendices
Appendix A - References
Appendix B - Trench and Boring Logs
Appendix C - Laboratory Testing Procedures and Test Results
Appendix D - General Earthwork and Grading Specification for Rough-Grading
Appendix E -Slope Stability
Appendix F -Seismic Analysis
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.0 INTRODUCTION
1.1 Purpose and Scope
This revised report presents the results of our geotechnical investigation for the proposed residential
development of the parcel located at the northeast comer of Poinsettia Avenue and Aviara Parkway in
Carlsbad, Califomia (see Figure 1). Our report has been revised due to a proposed change in site usage
(now residential) and the addition of a 1-acre parcel in the northwest comer. In addition, since the
issuance of our initial report, Poinsettia Lane has been con.stmcted across the southem portion of the
site. The purpose of our investigation was to evaluate the geotechnical conditions at the site and to
provide conclusions and recommendations relative to site development. The scope of our services
during the investigation included the following:
• Review of geotechnical literature pertaining to the general area of the site and geotechnical reports
pertaining specifically to the site. A list of the items reviewed is included in Appendix A.
• Field reconnaissance of the site and general vicinity.
• Subsurface exploration consisting of the excavation, logging and sampling of 9 exploratory
trenches and 5 small diameter borings to a maximum depth of 31 feet below existing grade. Logs
of the trenches and borings are presented in Appendix B.
• Laboratory testing of representative soil samples obtained during the subsurface exploration to
evaluate their pertinent engineering characteristics. Results of the laboratory tests are provided in
Appendix C.
• Geotechnical analysis of the data obtained.
• Preparation of this report presenting our findings, conclusions, and recommendations with respect
to the proposed development.
1.2 Site Description
The site is located at the northeast comer of Poinsettia Lane and Aviara Parkway in Carlsbad,
Califomia (see Site Location Map, Figure 1). The property is roughly L-shaped and encompasses
approximately 30.9 acres. The southwest portion of the subject site has most recently been used for
agricultural purposes. The northwest comer of the site has previously been utilized as a parking lot for
the adjacent development. Topographically, the site is characterized several ridges incised by two
main drainages. These drainages trend north/south and northeast/southwest. The surface elevations
onsite vary from 237 to 307 feet above mean sea level. The site is bordered to the north by open
space, to the south by Aviara Planning Area 24, to the west by Alga Road, and open space and
agricultural development to the east. Poinsettia Lane has recently been constmcted across the southem
portion of the site. Natural vegetation consists of thick bmsh on the hillsides and abundant weeds and
grasses in the lower areas. Surface water on the westem and central portions of the property drains to
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the north via the north-south trending ravine located in the central portion of the subject site. Surface
water on the southeastem portion of the site is directed south to southwest via a partially infilled ravine
which outlets into a storm drain located on the adjacent property immediately to the south. Several
utility easements transect the property. A 150 foot wide SDG&E easement for overhead power lines
crosses the eastem portion of the site and a 30 foot wide C.M.W.D. easement roughly bisects the
property trending northeast southwest.
1.3 Previous Site Grading
In general, previous site grading has included the tilling of the topsoil during the previous agricultural
activities onsite, and the creation of several access roads associated with utility easements and the
placement of compacted fill soils in the canyon at the southeast portion of the site during grading
operations for the adjacent Aviara Planning Area 24. The placement and compaction of these
compacted fill soils were observed and tested by others. This fill was placed to create positive
drainage into the storm drain inlet located immediately south of the subject parcels. Minor cuts and
fills were also made in the northwest comer of the site during the constmction of a small parking area.
These fills are considered undocumented.
During the period of time between our field investigation and the date of this report, Poinsettia Lane
has been graded under the observation of others. The alignment of Poinsettia Lane is shown on the
grading Geotechnical Map (Plate 1) and we have mapped the location of Artificial Fill placed by
others associated with this episode of grading. The fills placed during the grading of Poinsettia Lane
do not extend into the areas cunentiy proposed for development and are not anticipated to significantly
impact this development.
1.4 Proposed Development
Based on our review of the conceptual site plans provided by your office, we understand that the
project will consist of the constmction of a residential development comprised of 52 single-family
residences. Associated streets, driveways and landscape areas are also planned. We anticipate the
proposed stmctures will be one- to two-story stmctures of typical wood-frame constmction with a
concrete slab-on-grade floor. All proposed development is located north of Poinsettia Lane.
The proposed site grading will include the constmction building pads for 52 single-family residences
and with associated roads and landscape areas. Final grades for the building pads were not available at
the time of this report. A review of the grading plan when a final design has been established will be
required to identify any significant geotechnical issues related to the project design.
CITY OF
OCEANSIDE
PACIFIC
OCEAN
CITY
OF SAN
MARCOS
CITY OF
ENCINITAS
SITE LOCATION MAP
Poinsettia Village
Carlsbad, California
4980005-001 PROJECT NO.
SCALE
ENGR./GEOL. JGF/MRS
Not to scale
DRAFTED BY KAB
DATE November 1999 FIGURE NO. 1
4980005-002
2.0 SUBSURFACE INVESTIGATION
2.1 Field Investigation
Our subsurface investigation consisted of the excavation of 9 exploratory trenches to a maximum
depth of 15 feet below the existing ground surface, and the excavation of 5 exploratory small-diameter
borings to a maximum depth of 31 feet below the existing ground surface.
The purpose of the exploratory trenches and borings was to evaluate the engineering characteristics of
the onsite soils relative to the proposed development as well as estimate the depth to competent
bedrock material. Prior to commencing our excavations, Underground Service Alert was contacted
and a field meeting was scheduled to coordinate location and identification of nearby underground
utilities.
The trenches and borings were logged by a representative from our firm. Representative samples were
collected during our investigation for laboratory testing. The approximate locations of the borings and
trenches are shown on the Geotechnical Map, Plate 1 (located in map pocket). Logs of the borings and
trenches are presented in Appendix B.
Subsequent to logging, the trenches and borings were backfilled with the spoils material. Some minor
settlement of the backfill soils should be expected with time.
2.2 Laboratory Testing
Representative samples were tested for the following parameters:
- In-place moisture and density;
- Direct shear;
- Expansion index;
- Sulfate content;
- pH and minimum resistivity, and;
- Maximum density and optimum moisture content.
The results of our laboratory testing, along with a summary of the testing procedures, are presented in
Appendix C.
2.3 Regional Geologv
The project is situated in the coastal sub-provence of the Peninsular Ranges Geomorphic Provence,
near the westem edge of the southem Califomia batholith. This region has undergone several episodes
of marine inundation and regression during the last 54 million years. This has left a thick sequence of
marine and non-marine sediments overlying the Southem Califomia batholith. Recent periods of
tectonic uplift have lead to the erosion of these sediments creating the canyon and ridgeline
topography seen today.
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3.0 SUMMARY OF GEOTECHNICAL CONDITIONS
3.1 Site Geologv
As encountered during our investigation, the site is underlain by Quatemary Tenace Material and the
Tertiary Scripps Formation with a relatively thin mantle of Topsoil/Colluvium and localized deeper
areas of Quatemary Alluvium. An area of documented fill exists in the southeastem portion of the
site. These fill soils were placed during grading operations for the adjacent Aviara Planning Area 24
and documented by others. Artificial Fill documented by others also exists on the southem portion of
. the site along the alignment of Poinsettia Lane. Relatively minor amounts of undocumented fill soils
were also encountered during our investigation at several locations. A brief description of the units
encountered during our investigation is presented below. The approximate aerial extent of each of the
units is shown on the Geotechnical Map located at the rear of the text, (Plate No. 1.).
3.1.1 Undocumented Fill Soils (Map svmbol - Afli)
Undocumented fill soils were encountered onsite at the approximate locations depicted on
Plate 1, Geotechnical Map. These soils are considered uncompacted and as such are unsuitable
to receive improvements in their cunent condition. Approximately 10 feet of undocumented
fill was encountered in boring B-l. Therefore, these soils will require removal and
recompaction where encountered during site development.
3.1.2 Documented Fill Soils (Map Svmbol - Afd)
Documented fill soils placed during the grading operations for the adjacent Aviara Planning
Area (PA) 24 were encountered in the main drainage in the southem portion of the site. No
development is cunentiy planned in this area. As encountered these soils were generally
brown to light brown, moist, medium dense, silty sand to slightly clayey silty sand. Individual
lifts that varied from approximately 4 to 10 inches were observed in the trench walls.
Approximately 1 to 3 feet of saturated sandy silt to silty sand has been deposited over the
majority of this fill area. Therefore, the upper 3 to 5 feet of these soils will require removal and
recompaction where encountered during site development. Based on our review of pertinent
documents, up to ± 30 feet of compacted fill was placed within the subject site during grading
for PA24. According to our review of the As-Graded Geotechnical Report for PA24
(Geotechnics, 1995, Appendix A), saturated alluvial soils were left-in-place approximately as
shown on the Geotechnical Map presented at the rear of the text (Plate 1).
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3.1.3 Documented Fill Soils (Map Symbol - Afo)
Artificial fill soils placed during the grading operations for Poinsettia Lane were in the southem
portion of the site on and adjacent to the alignment of the road. An as-graded report of these
fills was not available for our review. These fills do not extend into the area proposed for
development and are not expected to impact the proposed project. The approximate extent of
these soils are shown on the Geotechnical Map presented at the rear of the text (Plate 1).
3.1.4 Topsoil/Colluvium (Map Symbol - Qcol)
The majority of the site is overlain by a relatively thin veneer of topsoil/colluvium. As
encountered in our trenches, this unit consists of loose to medium dense, silty sand to sandy
clays. In the southwest comer of the site the upper portion of this unit has been disturbed by
agricultural activities. This unit is potentially compressible and will require removal and
recompaction in areas proposed to receive fill or other stmctural improvements. The thickness
ofthis unit varied from 2 to 4 feet in our trenches and was generally unmapped. One mapped
and somewhat thicker deposit of colluvium is shown on Plate No. 1 in the vicinity of T-4. In
this area, colluvial soils were encountered up to 5 feet in depth although locally deeper areas
are anticipated.
3.1.5 Quatemary Alluvium (Map Symbol - Oal)
Quatemary-aged alluvium was encountered during our investigation in the lower portions of
the canyons which drain the site. These soils are typically loose to medium dense, clayey to
silty sands. These soils are potentially compressible in their present condition and will require
special treatment during site grading (see Recommendations, Section 6.0). The thickness of
this material varied from 2 to 10 feet below existing site grades in the southem portion of the
site although locally deeper areas may exist. Alluvial soils also underlie the undocumented fill
in the areas adjacent to Boring B-1 and in the area of the toe of the proposed fill slope in the
northem portion of the site. Based on the topographic expressions of the canyon area, alluvial
soils may exceed 10 feet in depth to the toe area.
3.1.6 Ouatemary Tenace Deposits (Map Symbol - Qt)
Quatemary-aged Tenace Deposits locally overly the Scripps Formation in several locations
across the site. These deposits were generally found along the ridgelines above approximately
270 feet mean sea level. As encountered during our investigation, these deposits generally
consisted of orange to reddish-brown, damp to moist, medium dense to very dense, clayey, fine
to coarse sand. The upper portion of this unit was highly weathered and locally porous in
localized areas. This unit was massive and abundant iron oxide staining was visible throughout
the exposures. In general, this material is suitable to receive additional fill or stmctural loads.
However, the upper weathered portion (minimum of 1 to 3 feet) of this unit should be removed
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and recompacted during site grading.
3.1.7 Tertiary Scripps Formation (Map Symbol - Tsc)
The mapped limits of this and other roughly time-equivalent units have locally varied
depending on which map is used as a reference. The same geologic unit has been mapped on
adjacent sites as Tertiary Toney Sandstone to the west. Tertiary Santiago to the north, and
undifferentiated Scripps/Toney to the south. For the purposes of this report we are using the
Scripps Formational name based on our field observations, experience on other nearby sites,
and mapping completed by Leonard Eisenberg (Eisenberg, 1983). In general, the unit consists
of massive to poorly bedded sandstone with interbedded clayey siltstone to silty claystone. The
sandstone encountered consisted primarily of light gray to light yellow-brown, moist, dense to
very dense, silty, fine- to medium grained sandstone. The sandstone was generally friable,
slightly micaceous and massive. The siltstone consisted of medium brown to olive brown,
moist, stiff, slightly clayey to clayey siltstone that was fissile to indistinctly bedded and
contained calcium carbonate, manganese oxide, and iron oxide staining. During our subsurface
investigation a 1-2 foot thick highly-expansive siltstone bed was encountered at an elevation
ranging from ± 277 feet msl in boring B-4 to ± 290 feet msl in boring B-5. Based on our
cunent site investigation as well as investigations performed on adjacent sites, this bed appears
to be laterally continuous dipping + 5° to the southwest. The claystone typically was gray to
brown, moist, stiff to hard, fine-grained, sandy to silty claystone that was moderately sheared.
This material is anticipated to be exported offsite during grading. Where encountered, the
upper 12 to 18 inches of the Scripps Formation appears to be weathered, porous and potentially
compressible. This weathered material should be removed and recompacted in areas of
proposed fill or other improvements.
3.2 Geologic Stmcture
The bedrock units encountered on the site were generally weakly bedded to massive with bedding of
the Scripps Formation dipping gently to the southwest.
3.3 Ground Water.
A static ground water table was not encountered during our field study. However, a perched
groundwater condition was encountered in trench T-4 at a depth of approximately 5 feet below the
existing ground surface. The water was encountered flowing at the contact between the overlying
colluvial material and the underlying, relatively less permeable Scripps Fomiation. Removal and
recompaction of this material and installation of a stability fill and subdrain will be required to
mitigate this condition. In addition, canyon subdrains will be required in deep fill areas to minimize
potential groundwater buildup. Therefore, it is our professional opinion that groundwater is not
expected to be a significant constraint to the proposed development provided the recommendations
of this report are adhered to. However, since relatively impermeable materials were encountered on
site, seepage conditions may locally be encountered after periods of heavy rainfall or inigation.
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These conditions can be treated on an individual basis if they occur.
3.4 Faulting
Our discussion of faults on the site is prefaced with a discussion of California legislation and policies
conceming the classification and land-use criteria associated with faults. By definition of the
Califomia Mining and Geology Board, an active fault is a fault that has had surface displacement
within Holocene time (about the last 11,000 years). The state geologist has defined a potentially
active fault as any fault considered to have been active during Quatemary time (last 1,600,000
years). This definition is used in delineating Earthquake Fault Zones as mandated by the Alquist-
Priolo Earthquake Fault Zones Act of 1972 and as most revised in 1997. The intent of this act is to
assure that unwise urban development and certain habitable stmctures do not occur across the traces
of active faults. The subject site is not included within any Earthquake Fault Zones as created by the
Alquist-Priolo Act.
Our review of available geologic literature indicates that there are no known major active faults
on or in the immediate vicinity of the site. The nearest known active regional faults are the Rose
Canyon Fault Zone and the offshore segment of the Newport-Inglewood Fault located
approximately 5 and 8 miles west and northwest of the site (Blake, 1996).
3.5 Seismicity
The site can be considered to lie within a seismically active region, as can all of Southem
Califomia. Table 1 identifies potential seismic events that could be produced by the maximum
credible earthquake. A maximum credible earthquake is the maximum expectable earthquake
given the known tectonic framework. Site-specific seismic parameters included in Table 1 are the
distances to the causative faults, earthquake magnitudes, and expected ground accelerations.
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Table 1
Seismic Parameters for Active Faults*
Maximum Peak Horizontal Horizontal
Probable Ground Ground
Earthquake Acceleration (g) Acceleration (g)
Potential Distance from (Moment Due to Maximum Due to Design
Causative Fault Fauh to Site Magnitude) Probable Event Earthquake
Rose Canyon 5 miles 5.7 0.32
Newport-
Inglewood
8 miles 5.8 0.25
0.31
Coronado Banks 21 miles 6.34 0.17
Elsinore-Julian 25 miles 6.4 0.15
* Based on Blake, 1996 and 1998.
As indicated in Table 1, the Rose Canyon fault is the active fault considered having the most
significant effect at the site from a design standpoint. The maximum probable earthquake of
moment magnitude 5.2 on the fault could produce an estimated peak horizontal ground acceleration
0.32g at the site.
From a probabilistic standpoint, we have performed a seismic hazard analysis to estimate the ground
motions having a 10 percent chance of exceedance in 50 years (UBC, 1997). The ground motion
having a 10 percent chance of exceedance in 50 years is refened to as the as the design earthquake.
The ground motion due to the design earthquake at the site is estimated to be 0.3 lg. Our seismic
analysis is included as Appendix F.
The effect of seismic shaking may be mitigated by adhering to the Uniform Building Code and
state-of-the-art seismic design parameters of the Structural Engineers Association of Califomia.
Based on the 1997 UBC, we provide the following design parameters:
Soil Profile Type = SQ (Table 16-J)
Seismic Zone = 4 (Figure 16-2)
Seismic Source Type = B (Table 16-U)
Na= 1.0 (Table 16-S)
Nv= 1.08 (Table 16-T)
Secondary effects that can be associated with severe ground shaking following a relatively large
earthquake include shallow ground rupture, soil liquefaction and dynamic settlement, seiches and
tsunamis. These secondary effects of seismic shaking are discussed in the following sections.
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3.5.1 Shallow Ground Rupture
Ground mpture because of active faulting is not believed to present a significant hazard to
the structure. Cracking due to shaking from distant seismic events is not considered a
significant hazard, although it is a possibility at any site.
3.5.2 Liquefaction and Dynamic Settlement
Liquefaction and dynamic settlement of soils can be caused by strong vibratory motion due
to earthquakes. Both research and historical data indicate that loose, saturated, granular soils
are susceptible to liquefaction and dynamic settlement while the stability of stiff silty clays
and clays and dense sands are not adversely affected by vibratory motion. Liquefaction is
typified by loss of shear strength in the affected soil layer, thereby causing the soil to behave
as a viscous liquid. This effect may be manifested by excessive settlements and sand boils at
the ground surface. Due to the relatively hard or dense nature of the onsite formational
materials and planned compacted fill soils, it is our opinion that the potential for seismically
induced soil liquefaction of these soils is low.
3.5.3 Tsunamis and Seiches
Based on the distance between the site and large, open bodies of water, and the elevation
of the site with respect to sea level, the possibility of seiches and/or tsunamis is
considered very low.
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4.0 CONCLUSIONS
Based on the results of our geotechnical investigation, it our opinion that the proposed development is
feasible from a geotechnical standpoint provided the following conclusions and recommendations are
incorporated into the design and construction of the subject project.
The following is a summary of the geotechnical factors that may affect development of the site.
• Based on our subsurface exploration and review of pertinent geotechnical reports, the site is underlain by
topsoil/colluvium, alluvium, Quatemary Tenace Deposits, and sandstone and to a lesser extent claystone
and siltstone of the Tertiary Scripps Formation.
• A highly expansive siltstone bed was encountered at an elevation ranging from approximately ± 277 feet
msl to + 290 feet msl. This siltstone bed may be exposed at, or exist near the proposed finish grade
elevations. If mapping during grading suggests that this may occur, additional recommendations such as
overexcavation and replacement with low expansion material or heavily reinforced foundation and slabs
may be required to mitigate potential adverse conditions.
Undocumented fill soils are present on site at various locations. These soils are considered uncompacted
in their present state and will require removal and recompaction prior to the placement of additional fill
soils or other improvements.
Documented fill soils exist in the southem portion of the subject site. These soils were placed during
grading for Poinsettia Lane and for the adjacent Aviara Planning Area 24. The documented fill soils do
not extend into the area proposed for development.
In general, the upper 2 to 4 feet of the onsite soils are unsuitable to receive the proposed improvements
in their cunent state and will require remedial grading such as removal and recompaction prior to site
development. Deeper removals may be required within the main drainages onsite.
Laboratory test results and our previous experience in the area indicate the topsoil/colluvium, and
alluvial soils, as well as the near surface formational soils present on the site have the following soil
engineering characteristics:
- Moderate to high expansion potential
- Negligible sulfate content
- Moderate hydroconsolldation potential in their present state
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As a result, these materials should be placed in the deeper fill areas or exported from the site. The
material to be exposed at the planned finish grade (and which will comprise the majority of the onsite
fills) will generally consist of materials of the Scripps Formation. These soils, in general, consist of
dense formational soils with favorable engineering properties such as:
- Low to medium expansion
- Good load-bearing capacity
- Negligible sulfate content
- Favorable pavement support characteristics
• The existing onsite soils appear to be suitable for use as fill material provided they are free of organic
material, debris, and rock fragments larger than 6 inches in maximum dimension.
• A permanent static shallow ground water table was not encountered during our investigation. Perched
ground water was encountered during our trenching investigation at a depth of approximately 5 feet
below existing grade in trench T-4. However, we anticipate that ground water will not be a significant
factor during site grading and constmction provided the recommendations presented in this report are
adhered to.
• Active or potentially active faults are not known to exist on the site.
• The maximum anticipated ground acceleration on the site due to the design earthquake is estimated to be
0.3 lg.
• Based on our evaluation, the potential for liquefaction and associated dynamic settlement at the site is
considered low.
• Final grading plans were not available for review at the time this report was prepared. Final plans will
require additional review and the possible need for additional recommendations.
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5.0 RECOMMENDATIONS
5.1 Earthwork
We anticipate that earthwork at the site vvill consist of site preparation, excavation, removal and
recompaction of potentially compressible soils, fill placement and backfill. We recommend that
earthwork on the site be performed in accordance with the following recommendations, the City of
Carlsbad grading requirements, and the General Earthwork and Grading Specifications included in
Appendix D. In case of conflict, the following recommendations shall supersede those in
Appendix D.
5.1.1 Site Preparation
Prior to grading, all areas to receive stmctural fill or engineered stmctures should be cleared
of surface and subsurface obstmctions, including any existing debris, potentially
compressible material (such as topsoil/colluvium, alluvium, weathered formational material,
and undocumented fill soils), and stripped of vegetation. Removed vegetation and debris
should be properly disposed of off site. Holes resulting from removal of buried obstmctions,
which extend below finished site grades, should be replaced with suitable compacted fill
material. All areas to receive fill and/or other surface improvements should be scarified to a
minimum depth of 6 inches, brought to near optimum moisture condition, and recompacted
to at least 90 percent relative compaction (based on ASTM Test Method D1557-91).
5.1.2 Removal and Recompaction of Potentially Compressible Soils
In general, alluvium, colluvium, topsoil, weathered formational soils, and undocumented fill
soils not removed by the planned grading, should be excavated, moisture conditioned or dried
back to near optimum moisture content, and then recompacted prior to placing any additional
fill soils. Typically, these soils including near-surface soils in areas that have been farmed in
the past are anticipated to be porous and potentially compressible in their present state, and
may settle appreciably under the surcharge of fills or foundation loading. In areas that will
receive fill or other surface improvements, these potentially compressible soils should be
removed down to competent formational materials and recompacted.
We recommend that the alluvium be either removed to formational material or to within ± 2
feet of the static ground water table if encountered. If saturated alluvial soils are left in place,
future differential settlement should be anticipated and the area should be monitored for
settlement prior to the constmction of improvements.
In general, we estimate the alluvial removals in the two main canyon portions of the site to be
up to ± 15 feet in depth. The colluvial removals will generally range from 2 to 8 feet, while
removals of topsoil and near surface soils disturbed by farming will be on the order of 2 to
4 feet. Removals of the undocumented fill soils encountered adjacent to the dirt access road
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in the west-central portion of the site will be on the order of 10 to 12 feet. Other areas of
undocumented fill soils, though limited in extent, will also require removal and recompaction
in areas of proposed improvements. It should be noted that these depths are estimates
provided for planning purposes only and are based on widely spaced excavations located
prior to the completion of final site development plans. Deeper removals may be required in
localized thicker zones of compressible soils.
5.1.3 Excavations
Excavations of the onsite materials may generally be accomplished with conventional heavy-
duty earthwork equipment. It is not anticipated that oversized rock (i.e. rock with maximum
dimensions greater than 6 inches) will be generated during grading. However, if oversized
rock is encountered, it should be placed as fill in accordance with the details presented in
Appendix D.
5.1.4 Fill Placement and Compaction
The onsite soils are generally suitable for use as compacted fill provided they are free of
organic material, debris, and rock fragments larger than 6 inches in maximum dimension.
All fill soils should be brought to near-optimum moisture conditions and compacted to
uniform lifts to at least 90 percent relative compaction based on laboratory standard ASTM
Test Method Dl 557-91. The optimum lift thickness required to produce a uniformly
compacted fill will depend on the type and size of compaction equipment used. In general,
fill should be placed in lifts not exceeding 8 inches in thickness.
Placement and compaction of fill should be performed in general accordance with the cunent
City of Carlsbad grading ordinances, sound constmction practice, and the General Earthwork
and Grading Specifications for Rough Grading presented in Appendix D.
5.2 Transition Lots
Site development plans were not yet completed at the time of this report. Transition lots may occur
during site grading operations. We recommend that the cut portion of the transition lots be
overexcavated a minimum of 4 feet below slab surface to reduce the potential for differential
settlement.
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5.3 Foundation Design
The majority of the onsite soils are anticipated to have a very low to low expansion potential.
However, as discussed, localized areas of medium to high expansive soils are present on site. As a
result, we provide the following preliminary foundation design recommendations for a range of soil
conditions. Final foundation recommendations can only be provided after expansion testing of the
site finish grade soils.
5.3.1 Conventionally Reinforced Foundation System - Low to Medium Expansion Soils
Conventionally-reinforced foundations should be designed and constmcted in accordance
with the recommendations contained in Table 2 based on the expansion potential of each lot
(which needs to be determined upon the completion of grading). Conventionally reinforced
foundations are only recommended for lots where the pad grade soils have an expansion
index less than or equal to 90 (per UBC 18-2) and a differential fill thickness of less than
20 feet.
The vapor banier recommended in Table 2 should be sealed at all penetrations and laps.
Moisture vapor transmission may be additionally reduced by use of concrete additives.
Moisture baniers can retard but not eliminate moisture vapor movement from the underlying
soils up through the slabs. We recommend that the floor coverings installer test the moisture
vapor flux rate prior to attempting applications of the flooring. "Breathable" floor coverings
should be considered if the vapor flux rates are high. A slipsheet or equivalent should be
utilized above the concrete slab if crack-sensitive floor coverings (such as ceramic tiles, etc.)
are to be placed directly on the concrete slab.
15
TABLE 2
MINIMUM FOUNDATION AND SLAB DESIGN RECOMMENDATIONS
U.B.C. Expansion Index
0-20
Very Low Expansion
U.B.C. Expansion Index
21-50
Low Expansion
U.B.C. Expansion Index
51-90
Medium Expansion
1-Story Footings
(See Note 1)
All footings 12" deep. Reinforcement for continuous
footings: one No. 4 bar top and bottom.
All footings 12" deep. Reinforcement for continuous
footings: one No. 4 bar top and bottom.
All footings 18" deep. Reinforcement for continuous
footings: one No. 4 bar top and bottom.
2-Story Footings
(See Note 1)
All footings 18" deep. Reinforcement for continuous
footings: one No. 4 bar top and bottom.
All footings 18" deep. Reinforcement for continuous
footings: one No. 4 bar top and bottom.
All footings 18" deep. Reinforcement for continuous
footings: one No. 4 bar top and bottom.
Minimum Footing Width Continuous: 12" for 1-stoiy
Continuous: 15" for 2-story
Isolated column: 24" (18" deep minimum)
Continuous: 12" for 1-stoiy
Continuous: 15" for2-stoiy
Isolated column: 24" (18" deep minimum)
Continuous: 12" for 1-story
Continuous: 15" for 2-story
Isolated column: 24" (18" deep minimum)
Garage Door Grade Beam
(See Note 2)
A grade beam 12" wide x 12" deep
(18" deep for 2-story) should be provided across the
garage entrance.
A grade beam 12" wide x 12" deep
(18" deep for 2-stoiy) should be provided across the
garage entrance.
A grade beam 12" wide x 18" deep
should be provided across the garage entrance.
Living Area Floor Slabs
(See Notes 3,4 and 6)
Minimum 4" thick slab. No 3 rebars at 18" on center or
No. 4 rebars at 24" on center (each way) at midheight.
2" clean sand over 6 mil moisture barrier.
Minimum 4" thick slab. No 3 rebars at 18" on center or
No. 4 rebars at 24" on center (each way) at midheight.
2" clean sand over 6 mil moisture barrier over 2" clean
sand.
Minimum 4" thick slab. No. 3 bars at 18" each way or
No. 4 bars at 24" each way. 2" clean sand over 6 mil
Visqueen over 2" clean sand.
Garage Floor Slabs
(See Notes 4, 5 and 6)
Minimum 4" thick on 2" sand base over moisture
barrier on pad. No 3 rebars at 18" on center or No. 4
rebars at 24" on center (each way) at midheight. Slab
should be quarter-sawn.
Minimum 4" thick on 2" sand base over moisture
barrier on pad. No 3 rebars at 18" on center or No. 4
rebars at 24" on center (each way) at midheight. Slab
should be quarter-sawn.
Minimum 4" thick on 2" sand base over moisture
barrier on pad. No. 3 bars at 18" each way or No. 4
bars at 24" each way. Slab should be quarter-sawn.
Presoaking of Living Area
and Garage Slabs
Near optimum to a depth of 6". 1.2 times the optimum moisture content to a depth of
12".
1.3 times optimum moisture content to a depth of 18".
Allowable Bearing Capacity
(one-third increase for short term
loading)
2,000 pounds per square foot
(one-third increase for short term loading)
2,000 pounds per square foot
(one-third increase for short term loading)
2,000 pounds per square foot
(one-third increase for short term loading)
Notes:
(1)
(2)
(3)
(4)
(5)
(6)
Depth of interior or exterior footing to be measured from lowest adjacent finish grade or drainage swale flowline elevation.
The base of the grade beam should be at the same elevation as that of the adjoining footings.
Living area slabs should be tied to the footings as directed by the structural engineer.
6-mil Visqueen sheeting or equivalents are acceptable. All laps and penetrations should be sealed.
Garage slabs should be isolated from stem wall footings with a minimum 3/8" felt expansion joint.
Sand base should have a Sand Equivalent of 30 or greater (e.g. washed concrete sand).
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Our experience indicates that use of reinforcement in slabs and foundations will generally
reduce the potential for drying and shrinkage cracking. However, some cracking should be
expected as the concrete cures. Minor cracking is considered normal; however, it is often
aggravated by a high water/cement ratio, high concrete temperature at the time of placement,
small nominal aggregate size, and rapid moisture loss due to hot, dry and/or windy weather
conditions during placement and curing. Cracking due to temperature and moisture
fluctuations can also be expected. The use of low slump concrete (not exceeding 4 to
5 inches at the time of placement) can reduce the potential for shrinkage cracking.
To slab subgrade soils underlying the conventional foundation systems should be presoaked
as indicated in Section 5.3.3 prior to placement of the moisture banier and slab concrete.
5.3.2 Post-Tension Foundation Design (Verv Low to Highly Expansive Soils)
We recommend post-tensioned slabs be designed in accordance with the following design
parameters presented on Table 3 and criteria of the cunent edition of the Uniform Building
Code. The post-tensioned foundations on the lots should be designed in accordance with lot-
specific expansion potential and anticipated long-term differential settlement (if applicable)
which will be provided at the completion of grading.
Table 3
Post-Tensioned Foundation Design Recommendations
for Expansive Soils
Design Criteria
Expansion Index (UBC 18-2)
Design Criteria
Very Low to
Low (0-50)
Medium
(50-90)
High (91-130)
Edge
Moisture
Variation, e^n
Center Lift: 5.5 feet 5.5 feet 5.5 feet Edge
Moisture
Variation, e^n Edge Lift: 2.5 feet 2.5 feet 2.5 feet
Differential
Swell, ym
Center Lift: 1.0 inches 2.0 inches 3.0 inches Differential
Swell, ym Edge Lift: 0.4 inches 0.8 inches 1.0 inches
Differential Settlement: 1/2 inch 1/2 inch 1/2 inch
Allowable Bearing Capacity: 2,000 psf 2,000 psf 2,000 psf
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The post-tensioned foundations and slabs should be designed in accordance with stmctural
considerations. Continuous footings (ribs or thickened edges) with a minimum width of 12
inches and a minimum depth of 12 inches below adjacent grade may be designed for a
maximum allowable bearing pressure of 2,000 pounds per square foot if founded into
competent formational soils or properly compacted fill soils. The allowable bearing
capacity may be increased by one-third for short term loading such as wind or seismic
forces. Where the foundation is within 3 feet (horizontally) of adjacent drainage swales, the
adjacent footing (thickened edge or rib) should be embedded a minimum depth of 12
inches below the swale flow-line.
Slabs should be underlain by a minimum of 2 inches of clean sand (sand equivalent greater
than 30) which is in tum underlain by a vapor banier and an additional 2 inches of clean
sand. The vapor banier should be sealed at all penetrations and laps. Moisture vapor
transmission may be additionally reduced by use of concrete additives. Moisture baniers
can retard, but not eliminate moisture vapor movement from the underlying soils up
through the slabs. We recommend that the floor covering installer test the moisture vapor
flux rate prior to attempting applications of the flooring. "Breathable" floor coverings
should be considered if the vapor flux rates are high. A slipsheet or equivalent should be
utilized above the concrete slab if crack-sensitive floor coverings (such as ceramic tiles,
etc.) are to be placed directly on the concrete slab.
Our experience indicates that use of reinforcement in slabs and foundations will generally
reduce the potential for drying and shrinkage cracking. However, some cracking should be
expected as the concrete cures. Minor cracking is considered normal; however, it is often
aggravated by a high water/cement ratio, high concrete temperature at the time of
placement, small nominal aggregate size, and rapid moisture loss due to hot, dry and/or
windy weather conditions during placement and curing. Cracking due to temperature and
moisture fluctuations can also be expected. The use of low slump concrete (not exceeding
4 to 5 inches at the time of placement) can reduce the potential for shrinkage cracking and
the action of tensioning the tendons can close small shrinkage cracks. In addition to the
careful control of water/cement ratios and slump of concrete, application of 50 percent of
the design post-tensioning load within three to four days of slab pour is found to be an
effective method of reducing the cracking potential.
The slab subgrade soils underlying the post-tensioned foundation systems should be
presoaked as indicated in Section 5.3.3 prior to placement of the moisture banier and slab
concrete.
5.3.3 Moisture Conditioning
The slab subgrade soils underlying both conventionally-reinforced or post-tensioned
foundation systems should be presoaked in accordance with the recommendations
presented in Table 7 prior to placement of the moisture banier and slab concrete. The
subgrade soil moisture content should be checked by a representative of Leighton and
Associates prior to slab constmction.
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Table 4
Minimum Presaturation Recommendations for Foundation Subgrade Soils
Presaturation
Criteria
Expansion Index (per UBC 18-2)
Presaturation
Criteria Very Low
(0-20)
Low
(21-50)
Medium
(51-90)
High
(91-130)
Minimum
Presoaking Depth
(in inches)
6 12 18 24
Minimum
Recommended
Moisture Content
near optimum
moisture
1.2 times
optimum
moisture
1.3 times
optimum
moisture
1.4 times
optimum
moisture
Presoaking or moisture conditioning may be achieved in a number of ways, but based on
our professional experience, we have found that minimizing the moisture loss of pads that
have been completed (by periodic wetting to keep the upper portion of the pad from drying
out) and/or berming the lot and flooding if for a short period of time (days to a few weeks)
are some of the more efficient ways to meet the presoaking requirements. If flooding is
performed, a couple of days to let the upper portion of the pad dry out and form a cmst so
equipment can be utilized should be anticipated.
5.4 Anticipated Settlement
Settlement of properly compacted fill soils can occur upon application of stmctural loads (elastic
settlement), the majority of which typically occurs during and slightly after constmction and upon
saturation due to water infiltration (hydroconsolldation settlement) which may occur over a period of
many years.
The recommended allowable-bearing capacity is generally based on a maximum total and differential
(elastic) settlement of 3/4 inch and 1/2 inch, respectively, upon application of stmctural loads.
Approximately 1/2 of this settlement is anticipated to occur during constmction. Actual settlement
can be estimated on the basis that settlement is roughly proportional to the net contact bearing
pressure.
Long-term (hydroconsolldation) settlement is not anticipated to be a design concem since the
preliminary grading plan does not cunentiy indicate a significant fill differential below the proposed
stmctures. This will be further evaluated during grading.
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5.5 Retaining Wall Design Considerations
Embedded stmctural walls should be designed for lateral earth pressures exerted on them. The
magnitude of these pressures depends on the amount of deformation that the wall can yield under
load. If the wall can yield enough to mobilize the full shear strength of the soil, it can be designed for
"active" pressure. If the wall cannot yield under the applied load, the shear strength of the soil cannot
be mobilized and the earth pressure will be higher. Such walls should be designed for "at rest"
conditions. If a stmcture moves toward the soils, the resulting resistance developed by the soil is the
"passive" resistance.
For design purposes, the recommended equivalent fluid pressure for each case for walls founded
above the static ground water table and backfilled with soils of very low to low expansion potential is
provided below. Moderately to highly expansive soils should not be used behind retaining walls.
Onsite soils are suitable for use as retaining wall backfill provided they are free from debris and have
an expansion potential less than 50 (per UBC Standard 18-2).
Equivalent Fluid Weight (pcf)
Condition Level 3:1 Slope 2:1 Slope
Active
At-Rest
Passive
35
55
300
(Maximum of 3 ksf)
50
60
300
(Maximum of 3 ksf)
55
65
300
(Maximum of 3 ksf)
The above values assume free-draining conditions. If conditions other than those assumed above are
anticipated, the equivalent fluid pressure values should be provided on an individual-case basis by
the geotechnical engineer. All retaining wall stmctures should be provided with appropriate
drainage. The outlet pipe should be sloped to drain to a suitable outlet. Typical drainage design is
illustrated in Appendix D.
Wall back cut excavations less than 3 feet in height can be made near vertical. For back cuts greater
than 3 feet in height, but less than 15 feet in height, the back cut should be flattened to a gradient of
not steeper than 1:1 (horizontal to vertical) slope inclination. For back cuts in excess of 15 feet in
height, specific recommendations should be requested from the geotechnical consultant.
As previously mentioned, the walls should be backfilled with granular material. The granular
material backfill should be brought up to a height of approximately 2 feet below the top of the walls
and capped with compacted fill consisting of native soils. The granular and native backfill soils
should be compacted to at least 90 percent relative compaction (based on ASTM Test Method
D1557-91). The granular fill should extend horizontally to a minimum distance equai to one-half the
wall height behind the walls. The walls should be constmcted and backfilled as soon as possible
after back cut excavation. Prolonged exposure of back cut slopes may result in some localized slope
instability.
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Soil resistance developed against lateral stmctural movement can be obtained from the passive
pressure values in the previous table. Further, for sliding resistance, a friction coefficient of 0.35
may be used at the concrete and soil interface. These values may be increased by one-third when
considering loads of short duration including wind or seismic loads. The total resistance may be
taken as the sum of the frictional and passive resistance provided the passive portion does not exceed
two-thirds of the total resistance.
Foundations for retaining walls in competent formational soils or properly compacted fill should be
embedded at least 18 inches below lowest adjacent grade. At this depth, an allowable bearing
capacity of 2,000 psf may be assumed. Retaining wall footings should be founded entirely on
formational materials or properly compacted fill. Undercutting of the formational soils may be
necessary.
5.6 Foundation Setbacks
We recommend a minimum horizontal setback distance from the face of slopes for all stmctural
footings (retaining walls, building footings, etc.). This distance is measured from the outside edge of
the footing, horizontally to the slope face (or to the face of a retaining wall) and should be a
minimum of H/2, where H is the slope height (in feet). The setback should not be less than 7 feet and
need not be greater than 10 feet. Please note that the soils within the stmctural setback area possess
poor lateral stability, and improvements (such as retaining walls, sidewalks, fences, pavements, etc.)
constmcted within this setback area may be subject to lateral movement and/or differential
settlement. Potential distress to such improvements may be mitigated by providing a deepened
footing or a pier and grade beam foundation system to support the improvement. The deepened
footing should meet the setback as described above.
5.7 Tvpe of Cement for Constmction
Representative samples of the soils anticipated to be near finish grade were obtained and tested for
soluble sulfate content (Appendix C). Results of these tests indicate that these soils have a negligible
sulfate content. As a result, concrete in contact with the onsite soils can most likely be normal Type
II cement (or equivalent) in accordance with the UBC 1997, Table 19-A-4.
5.8 Conosion Resistance
Samples of the representative onsite soils were tested for minimum resistivity and pH by Califomia
Test Method 643. The results of this testing (Appendix C) indicate that the soils have a heavy
conosion potential in clayey soils and a minor potential for conosion to buried uncoated metal
conduits in sandy soils. A conosion engineer should be consulted for fiirther evaluation of this
potential if buried metal conduits are proposed.
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5.9 Slope Stability
Final grading plans are not yet available for review. For planning purposes, we anticipate cut and fill
slopes up to approximately 25 feet and 55 feet, respectively are planned at 2:1 (horizontal to vertical)
slope inclinations or flatter. Based on our analysis (Appendix E) of the geotechnical conditions
encountered during our investigation, it is our opinion that cut slopes will be grossly stable at slope
ratios of 2:1 (horizontal to vertical) or flatter. We recommend that the geotechnical consultant
document and geologically map all excavations, including cut slopes, during constmction. The
purpose of this mapping is to substantiate the geologic conditions assumed in our analysis. Proposed
fill slopes constmcted of onsite materials should be stable at inclinations of 2:1 (horizontal to vertical)
or flatter (Appendix E). The parameters used in our analysis are based on the results of our laboratory
testing, experience, and our professional judgement. Final grading plans showing the design of all
proposed cut and fill slopes should be reviewed by this consultant prior to site grading.
Based on our experience with similar materials, we anticipate that the slopes constmcted on the site
will also have acceptable factors of safety as related to surficial stability (Appendix E).
5.10 Preliminary Pavement Design
Final pavement recommendations should be provided based on R-value testing of roadway subgrade
soils as final grades are achieved. For planning purposes onlv. we have assumed the onsite soils will
have an R-value of 35. Utilizing assumed traffic indices of T.I. = 5.0, T.I = 6.0, and T.I. = 7.0, the
following stmctural pavement sections can be assumed for planning purposes. The project
architect/civil engineer should choose the approximate traffic index. Subgrade soils should be
obtained by the project geotechnical engineer during grading for R-value testing, to determine the
final pavement design.
Traffic Index R-Value Stmctural Pavement Design
Driveway, Parking and
Light Auto Traffic
T.I. = 5.0
R=35 3.0 inches of asphalt concrete over 5
inches of Caltrans Class 2 base
Drive Areas
T.I. = 6.0
R=35 3.5 inches of asphalt concrete over 6.5
inches of Caltrans Class 2 base
Heavy Auto and Tmck
Traffic/Fire Lanes
T.I. = 7.0
R=35 4.0 inches of asphalt concrete over 8
inches of Caltrans Class 2 base
The upper 12 inches of subgrade soils should be scarified, moisture conditioned and compacted to a
minimum of 95 percent relative compaction based on ASTM Test Method D1557-91. If fill is
required to reach subgrade design grade, fill placement should be performed in accordance with the
recommendations presented in Section 5.1. The aggregate base material should be compacted to 95
percent relative compaction. Areas of impact loading (such as from trash tmcks, etc.) should have a
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4980005-002
minimum 7 inches of Portland Cement Concrete on 2 inches of Class 2 base with appropriate
reinforcement and crack-control joints.
Asphalt Concrete (A.C), Portland Cement Concrete (P.C.C.) and Class 2 base materials should
conform to and be placed in accordance with the latest revision of the Califomia Department of
Transportation Standard Specifications (Caltrans) and American Concrete Institute (ACI) codes.
5.11 Graded Slopes
It is recommended that all graded slopes within the development be planted with ground cover
vegetation as soon as practical to protect against erosion by reducing mnoff velocity. Deep-rooted
vegetation should also be established to protect against surficial slumping. Oversteepening of
existing slopes should be avoided during fine grading and constmction unless supported by
appropriately designed retaining stmctures. Property compacted slopes at inclinations equal to or
flatter than 2:1 (horizontal to vertical) to heights of 20 to 30 feet are considered grossly stable. Due
to the expansive nature of the site surficial soils, surficial sloughing after periods of
inigation/precipitation may occur until the slope vegetation is well established.
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6.0 CONSTRUCTION OBSERVATION
The recommendations provided in this report are based on subsurface conditions disclosed by widely
spaced exploratory trenches/borings and geotechnical analysis. The interpolated subsurface conditions
should be checked in the field during constmction by a representative of Leighton and Associates. We
recommend that all cut and fill slopes, removals, and footing excavations be geologically mapped for the
presence of potentially adverse geologic conditions and potential ground water seepage zones by an
engineering geologist from Leighton and Associates during grading. A representative of this firm should
observe all grading operations so that constmction is performed in accordance with the recommendations of
this report. Grading plans and final project drawings should be reviewed by this office prior to constmction.
24-
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APPENDIX A
REFERENCES
Abbott, P.L., ed., 1985, On the Manner of Deposition of the Eocene Strata in Northem San Diego County;
San Diego Association of Geologists Fieldtrip Guidebook, April 13, 1985.
Albee, A.L., and Smith, J.L., 1966, Earthquake Characteristics and Fault Activity in Southem Califomia in
Lung, R. and Proctor, R., Editors, Engineering Geologist, Special Publication, dated October 1966.
Allen, C.R., Amand, P., Richter, C.F., and Nordquist, J.M., 1965, Relationship Between Seismicity and
Geologic Stmcture in Southem Califomia, Seismological Society of America Bulletin, Vol. 55, No.
4, pp. 753-797,1965.
Blake, 1996, EQ Fault.
, 1998, Frisk SP.
Bolt, B.A., 1973, Duration of Strong Ground Motion, Proc. Fifth World Conference on Earthquake
Engineering, Rome, Paper No. 292, pp. 1304-1313, June 1973.
Califomia Division of Mines and Geology, 1975, Fault Map of Califomia, Scale 1 "=750,000".
Campbell, 1993, Empirical Prediction of Near Surface Ground Motion from Large Earthquakes," Proc.
Intemational Workshop on Earthquake Hazard and Large Dams in the Himalaya (INTACH), New
Delhi, India, January 15-16.
Eisenberg, L.L, 1983, Pleistocene Tenaces and Eocene Geology, Encinitas and Rancho Santa Fe
Quadrangles, San Diego County, Califomia, San Diego State University Master's Thesis
(unpublished), p. 386.
_, 1985, Pleistocene Faults and Marine Tenaces, Northem San Diego County in Abbott, P.L.,
editor. On the Manner of Deposition of the Eocene Strata in Northem San Diego County, San
Diego Association of Geologists, Field Trip Guidebook, pp. 86-91.
Geotechnics, Inc., 1995, As-Graded Geotechnical Report, Aviara Planning Area (PA) 24, Carlsbad,
Califomia, Project No. 0073-003-00, Doc. #4-03 80
Hannan, D. 1975, Faulting in the Oceanside, Carlsbad and Vista Areas, Northem San Diego County,
Califomia in Studies on the Geology of Camp Pendleton and Westem San Diego County,
Califomia: San Diego Association of Geologists, pp. 56-59.
4980005-002
APPENDIX A (continued)
Hart, 1994, Fault-Rupture Hazard Zones in Califomia, Alquist-Priolo Special Studies Zones Act of 1972
with Index to Special Study Zones Maps, Department of Conservation, Division of Mines and
Geology, Special Publication 42, 1972.
ICG, Inc., 1990, As-Graded Geotechnical Report, Volume 1, Units A Through E, Aviara, Carlsbad,
Califomia, JobNo. 04-3179-007-02-10, Log No. 0-1094, Dated January 18, 1990
Intemational Conference of Building Officials, 1994, Uniform Building Code.
Jennings, C.W., 1975, Fault Map of Califomia, Scale 1:750,000, Califomia Division of Mines and Geology,
Geologic Map No. 1, 1975.
Lamar, D.L., Merifield, P.M., and Proctor, R.J., 1973, Earthquake Recunence Intervals on Major Faults in
Southem Califomia in Moran, D.E., Slosson, J.E., Stone, R.O., Yelverton, Califomia, Editors,
1973, Geology, Seismicity, and Environmental Impact, Association of Engineering Geologists,
Special Publication, 1973.
Leighton and Associates, Inc., 1992, City of Carlsbad Geotechnical Hazards Analysis and Mapping Study,
84 Sheets, November 1992.
O'Day Consultants, 1997, 100-Scale Preliminary Grading Study, Sarkaria/Schindler Properties, Sheet 1 of
1, Job No. 97-1039-08, dated April 10, 1997.
_, 1997a, 50-Scale Topographic Map Showing Property Lines, Existing Easements, and
Proposed Alignment of a Portion of Poinsettia Lane, Sheet 1 of 1, dated November 11, 1997.
_, 1997b, 50-Scale Site Plan for Sarkaria/Schindler Properties (Proposed Poinsettia Village
Commercial Site), Sheet 1 of 1, dated January 30, 1998.
Real, C.R., Toppazada, T.R., and Parke, D.L., 1978, Earthquake Epicenter Map of Califomia, Califomia
Division of Mines and Geology, Map Sheet 39.
San Diego Soils Engineering, Inc., 1988, Supplemental Geotechnical Investigation Pacific Rim Country
Club and Resort Units A, B, C, and C and Alga Road Conidor, Carlsbad, Califomia, Job No. 04-
3179-003-00-00, Log No. 8-1335, Dated March 25, 1988.
_, 1986, Preliminary Geotechnical Investigation The Pacific Rim Country Club And Resort
Phase I, Carlsbad, Califomia, Project No. sdl400-01, Log No. 3733, Dated Jan 29, 1986.
A-2
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APPENDIX A (continued)
Schnabel, B. Seed, H.B., 1974, Accelerations in Rock for Earthquakes in the Westem United States;
Bulletin of the Seismological Society of America, Vol. 63, No. 2, pp. 501-516, 1974.
Seed, H.B., Idriss, I.M., and Kiefer, F.W., 1969, Characteristics of Rock Motions During Earthquakes,
Joumal of Soil Mechanics and Foundations Divisions, ASCE, Vol. 95, No. SM5, Proc. Paper 6783,
pp. 1199-1218, September, 1969.
United States Department of the Interior Geologic Survey, 1968, 7.5-Minute Encinitas Quadrangle, Scale
1:24,000, Photo Revised 1975.
Weber, H.F., 1982, Recent Slope Failures, Ancient Landslides, and Related Geology of the North-Central
Coastal Area, San Diego County, Califomia, Califomia Division of Mines and Geology, Open-File
Report 82-12LA.
Wilson, K.L., 1972, Eocene and Related Geology of a Portion of the San Luis Rey and Encinitas
Quadrangles, San Diego, Califomia.
A-3
GEOTECHNICAL BORING LOG KEY
Date
Projea
Drilling Co.
Hole Diameter
Elevation Top of Hole +!-_
KEY TO BORING LOG GRAPHICS
Sheet 1
Project No.
T^peof Rig
of
Drive Weight
ft. Ref. or Datum
Drop m.
Ui
Q^;
V) x:o) (U ao +-(O-J o z
o z
a
tt
tn
CH-01 U Q Q. \^
3t C Q
3
I/t
O '
GEOTECHNICAL DESCRIPTION
Logged By
Sampled By
10-
15-
25—
5>x<>5>x<?
30:
CL
CH
Inorganic clay of low to medium plasticity, gravelly day; sandy claj^ silty clay; lean
clay
Inoiiganic clay of high plasticity; fat clay
OL-OH
ML
r ndicate:
SPT
Sample
indicate;
Cal
Sample
Oiganic clay, silt or silty clay-clayey silt mixtures
Inorganic silt; vciy fme sand; silty or clayey fine sand; clayey silt with low plasticity
MH
CL-ML
Inorganic silt; diatomaceous fine sandy or silty soils; elastic silt
Low plasticity clay to silt mixture
ML-SM
C^SC
Sandy silt to silty sand mixture
Sandy clay to clayey sand mixture
^iScates ground
water level at
time of tttWng
SOSM
SW
Qayey sand to silty sand mixture
WeU graded sand; gravelly sand, little or no fines
SP
SM
Poorly graded sand; gravelly sand, little or no fines
Silty sand; pooriy graded sand-silt mixture
SC
GW
Clayey sand; pooriy graded sand-clay mixture
Well graded gravel; gravcI-sand mixture, little or no fines
GP
GM
Pooriy graded gravel; gravel-sand mixture, little or no fines
Silty gravel; gravcl-sand-eilt mixture
GC Clayey gravel; gravel-sand-clay mixture
Sandstone
Siltstone
Clajstonc
Breccia (angular gravel and cobbles or matrix-supported conglomerate)
Congjiomeiate (rounded gravel and cobble, clast-supported)
Igneous granitic or granitic type rock
Metavolcanic or metamorphic rock
Artificial or man-made fill
Asphaltic concrete
Portland Cement Concrete
505A<11/77) LEIGHTON & ASSOCIATES
1-27-98 Date
Project
Drilling Co. _
Hole Diameter
Elevation Top of Hole + /- 287
GEOTECHNICAL BORING LOG B-1
Poinsettia Village
of 1
980005-001
Scott's Drilling Service
Sin. Drive Weight
ft. Ref. or Datum
140 pounds
Mean Sea Level
Sheet 1
Project No.
Type of Rig Hollow-Stem Auger
Drop 30 in.
QJ (0
UJ
Q3
u
jztn
QLO >o_i L CD
Ql
O Z
a
E 10 Ui
CH-OI o
a a
L
a
^ 0)
o o
GEOTECHNICAL DESCRIPTION
Logged By
Sampled By
KBC
KBC
285-
5—
280-
10-
275-
15-
270
20-
265
25—
260
I 98.0 8.3
I 27 1.6
3 • 50/5" 6.2
SM
SM
SM
ARTIFICIAL FILL - Undocumented (Afu)
@ 0': Light orange-brown, damp, medium dense, silty, fine to medium SAND
@ 5': Light orange-brown, moist, very loose, silty, fine to medium SAND
TOP.SOIT.
@ 10': Light brown, damp, medium dense, silty, fine to medium SAND; fine to
medium pores common
TERITARY SCRIPPS FORMATION (Tsc-)
@ 12.5': Drilling became more difficult (per driller)
@ 15': Light gray and brown, dry, very dense, silty, fine to medium \ SANDSTONE; few fine to medmm pores, fracture in sample
Total Depth = 15.5 Feet
No Ground Water Encountered at Time of Drilling
Hole Backfilled on January 27,1998
505A(11/77) LEIGHTON & ASSOCIATES
Date 1-27-98
Project
Drilling Co.
GEOTECHNICAL BORING LOG B-2
Poinsettia Village
Sheet 1 of 1
Project No. 980005-001
Scott's Drilling Service Type of Rig Hollow-Stem Auger
Hole Diameter 8 in. Drive Weight 140 pounds Drop 30 in.
Elevation Top of Hole +1- 299 ft. Ref. or Datum Mean Sea Level
UJ
u
Q.O
L CD
Ifl 0)
0. B
tn Q.
Itirs CM-Oi U
a a
3) L
a
in
^ o
CJ
CJ CJ
.t/J
O^
GEOTECIINICAL DESCRIPTION
Logged By
Sampled By
KBC
KBC
295
290
10-
285
15-
280
20-
275
25 —
270
g-1 '-4'
SM TOPSOIL
@ 1': Red brown, moist, medium dense, silty fine to medium SAND
SM
I 50/6.5° 113.1 8.1
OUATERNARY TERRACE DEPOSITS rOt^
@ 3.5': Drilling became more difficult (per driller)
@ 5': Brown and light gray with orange-brown staining, moist, very dense, slightly
clayey, silty, fine to medium SANDSTONE; medium pores common
I 89/10" 105.5 13.7 SM TERTL\RY SCRIPPS FORMATION (Tsc>
@ 10": Off-white, moist, very dense, silty, fine SANDSTONE
4 I 50/6" 107.5 10.5 SP 15': Very light brown, moist, veiy dense, fine to medium SANDSTONE
5 i50/6.5' 104.2 13.0 ' 20": Off-white, moist, vety dense, fine to medium SANDSTONE
6 1 42/6" 104.7 14.5 I 25': Vety light brown, moist, very dense, fine to medium SANDSTONE
Total Depth = 25.5 Feet
No Ground Water Encountered at Time of Drilling
Hole Backfilled on January 27, 1998
505A(11/77) LEIGHTON & ASSOCIATES
1-27-98 Date
Project
Drilling Co.
Hole Diameter
Elevation Top of Hole +1- 298
GEOTECHNICAL BORING LOG B-3
Poinsettia Village
Sheet
Project No.
of 1
980005-001
Scott's Drilling Service
Sin. Drive Weight
ft. Ref. or Datum
140 pounds
Mean Sea Level
Type of Rig Hollow-Stem Auger
Drop 30 in.
0)3
UJ
Q3
u
Q.O <0_J
c
CD
Ml 0)
O
z Q.
n a.
CH-ta u a Q.
3) c o
(U
o o
_C/J
o3
OJ
GEOTECHNICAL DESCRIPTION
Logged By
Sampled By
KBC
KBC
295-
290
285
280
275
10-
15—
20-
25-
SM OUATERNARY TERRACR DEPOSFTS (0<L\
@ 0': Red-brown, moist, medium dense, silty, fine to medium SAND
SM
I 38 110.1 16.1
TERTIARY SCRIPPS FORMATION (Tsc)
@ 3.5': Change of material in cuttings, more dense (per driller)
@ 5': Light gray, moist, medium dense, silty, fine SANDSTONE; orange-brown
staming common, few fractures
I 2 I 68 111.8 16.9 ' 10': Light gray, moist, dense, silty, fine SANDSTONE; yellow to orange-brown
stains common
3 150/6 ! 15': Light gray and very light brown, damp, very dense, silty, fine
SANDSTONE, thinly bedded, few yellow to orange-brown stains
I 50/6" 120': Off-white, damp, very dense, silty, fine SANDSTONE
1 50/6" > 25': Off-white, damp, very dense, silty, fine SANDSTONE
270-
Total Depth = 25.5 Feet
No Ground Water Encountered at Time of Drilling
Hole Backfilled on January 27,1998
505A(11/77) LEIGHTON & ASSOCIATES
Date 1-27-98
Project
Drilling Co.
GEOTECHNICAL BORING LOG B-4
Poinsettia Village
Sheet 1
Project No.
of
980005-001
Scott's Drilling Service Type of Rig Hollow-Stem Auger
Hole Diameter 8 in. Drive Weight 140 pounds Drop 30 in.
Elevation Top of Hole +1- 297 ft. Ref. or Datum Mean Sea Level
It
UJ
u
0) Q.O 01-1
c
CD
ISI 01
O
z
o z
a.
B n (/J
iti/-\ CM-Oi u
a Q.
L
a
»fl fc
^ o
CJ cn
GEOTECHNICAL DESCRIPTION
Logged By
Sampled By
KBC
KBC
295
290-
10-
285-
15-
280
20-
Bag-1
@r-4'
No
sample
retained
275
25-
270
2SL
I 41
I 56
I 33
I 5 I IS
I 6 I 59
113.4 12.4
120.3 10.2
89.6 32.1
SM
SM
SP
SM
CL
SP
TOPSOIL
@ 0': Red-brown, moist, medium dense, slightly clayey, silty, fine to medium
SAND
OUATERNARY TERRACE DEPOSITS (Oil
@ 3': Drilling more difficult (per driller)
I 5': Brown, moist, medium dense, silty, fine to coarse SANDSTONE; few
medium pores
10': Red-brown, moist to wet, dense, medium to coarse SANDSTONE;
medium pores cotnmon
TERTIARY SCRIPPS FORMATION fTsc)
@ 15': Gray-brown and red-brown, wet to samrated, medium dense, silty, fine to
medium SANDSTONE; moderately fractored
I 20": Gray, moist, stiff, silty, CLAYSTONE; plastic
I 25': Reddish brown, damp, dense, coarse SANDSTONE; fine gravel common
505A(11/77) LEIGHTON & ASSOCIATES
GEOTECHNICAL BORING LOG B-4
1-27-98 Date
Project
Drilling Co. _
Hole Diameter
Elevation Top of Hole -i- /- 297 ft.
Poinsettia Village
Scott's Drilling Service
Sheet 2
Project No.
Type of Rig
of
980005-001
Sin. Drive Weight
Ref. or Datum
140 pounds
Mean Sea Level
Hollow-Stem Auger
Drop 30 in.
It
o
Q.O
n)_l £. CD
HI 01
a.
cn
ca fc a.
ifi^
CH-OI u
a 0.
31
a
2-H
• o
CJ
GEOTECHNICAL DESCRIPTION
Logged By
Sampled By
KBC
KBC
30-7 I 50/6" SM
265-
35-
260-
40-
255
45-
250
50-
245
55-
240-
TERTIARY SCRIPPS FORMATION rContinuedl
\@ 30': Off-white, damp, very dense, silty, fine SANDSTONE
Total Depth = 30.5 Feet
No Ground Water Encountered at Time of Drilling
Hole Backfilled on January 27,1998
505A(11/77) LEIGHTON & ASSOCIATES
Date. 1-27-98
Project
Drilling Co.
GEOTECHNICAL BORING LOG B-5
Poinsettia Village
Sheet 1 of 2
ProjectNo. 980005-001
Scott's Drilling Service Type of Rig Hollow-Stem Auger
Hole Diameter 8 in. Drive Weight 140 pounds Drop 30 in.
Elevation Top of Hole + /- 305 ft. Ref. or Datum Mean Sea Level
I'
LLI
Q3
u !co) ao n)_i
L CD
Ifl 0>
O
z Q. B m C/J
to fc
D.
CH-(U o Q a
31 L
a
w fc
^ o
CJ
Gcj
cn'
GEOTECHNICAL DESCRIPTION
Logged By
Sampled By
KBC
KBC
305
300
295 10-
290-15-
285 20—
280 25-
1
lA
2 I
I
79
93
79
I 88/9"
112.6
101.9
SM
SM
18.0 CL/ML
SM
9.1
QUATERNARY TERRACE DRPO.SrrS rOt;i
@ 0': Red-brown, damp, dense, silty, fine to medium SANDSTONE
17': Material became slightly coarser
TERTIARY SCRIPPS FORMATION rrsc;i
@ 11': Off-white, moist, dense, silty, fine SANDSTONE
115': Rose-brown and light gray, damp, hard, silty, CLAYSTONE to clayey
SILTSTONE
> 16.25': Off-white, damp, veiy dense, silty, fine SANDSTONE
> 20': Off-white, damp, very dense, silty, fine SANDSTONE
I 25': Very light brown, moist, very dense, silty, fine to medium SANDSTONE
505A(11/77) LEIGHTON & ASSOCIATES
GEOTECHNICAL BORING LOG B-5
1-27-98 Date
Project
Drilling Co.
Hole Diameter
Elevation Top of Hole +/- 305 ft.
Poinsettia Village
Scott's Drilling Service
Sheet 2
Project No.
Type of Rig
of
980005-001
Sin. Drive Weight
Ref. or Datum
140 pounds
Mean Sea Level
Hollow-Stem Auger
Drop 30 in.
tu
a3
u
.n. 0) ao Ol-I c CD
Ifl Oi
a
E m cn
\ti/-\
CH-
a a
31 L Q
ai'5
w fc
o u
_cn
'oB
CO
GEOTECHNICAL DESCRIPTION
Logged By
Sampled By
KBC
KBC
275 30-
270-35—
265 40—
260 45-
255 50-
250 55-
ML
5Q/5" SM TERTIARY SCRIPPS FORMATION (Continued)
\@ 30': Very light brown, dry, very dense, silty, fine to medium SANDSTONE V
Total Depth = 30.5 Feet
No Ground Water Encountered at Time of Drilling
Hole Backfilled on January 27,1998
505A(11/77) LEIGHTON & ASSOCIATES
LOG OF TRENCH NO.: T-1
Project Name: Poinsettia Village
Project Number: 4980005-001
Equi pment: JD 710 4X4 Backhoe
Logged by:.
Elevation:.
Location:
KAB
+/-285'
Carlsbad
Ol
o
I
>
(0
o
GEOLOGIC
AHITUDES DATE: 1/27/98 DESCRIPTION:
GEOLOGIC
UNIT
ENGINEERING PROPERTIES
USCS
Sample
No.
Moist.
{%)
Density
(pcf)
TOPSOIL
A (a 0-1.5': Brown, damp, loose to soft, clayey, silty sand;
abundant organics; roots common
TERTIARY SCRIPPS FORMATION
Topsoi1
Tsc
SM
SM
@ 1.5'-5.75' Light orange-brown to yellow-brown, damp, dense
to very dense, slightly silty sandstone;
abundant iron-oxide staining and minor
manganese-oxide staining visible, massive to
weakly bedded, bedding discontinuous
Si
o
3
>
(0 Ot o o
»•
(0
GRAPHIC REPRESENTATION: N.W. Wall SCALE: 1" =5' SURFACE SLOPE: 15°NE TREND: N60°E
llll llll llll llll llll llll llll •4-4-4-
TOTAL DEPTH AT 5.75'
NO GROUND WATER
ENCOUNTERED
BACKFILLED: 1/27/98
LOG OF TRENCH NO.: T-2
o
I
>
<0
o
o
3
>
(0
(0 o o
»•
Project Name: Poinsettia Village Project Number: 4980005-001
Equi pment: JD 710 4X4 Backhoe
Logged by:.
Elevation:.
Location:
KAB
+/-285'
Carlsbad
GEOLOGIC
ATTITUDES DATE: 1/27/98 DESCRIPTION:
TOPSOIL
A @ 0-1.25' Brown, damp, soft, loose, slightly clayey silty,
fine to medium sand; abundant organics
TERTIARY SCRIPPS FORMATION
(a 1.25'-5.5' Very light greenish gray, damp, dense to very
dense, silty fine sand
GEOLOGIC
UNIT
Topsoi1
Tsc
ENGINEERING PROPERTIES
USCS
SM
SM
Sample
No. Moist. Density
(pcf)
GRAPHIC REPRESENTATION: N.W. Wall SCALE: 1" = 5' SURFACE SLOPE: 15°NE TREND: N80°E
llll llll llll llll llll llll llll llll
TOTAL DEPTH AT 5.5'
NO GROUND WATER
ENCOUNTERED
BACKFILLED: 1/27/98
LOG OF TRENCH NO.: T-3
Project Name: Poinsettia Village
Project Number:.
Equipment: 4980005-001
JD 710 4X4 Backhoe
Logged by:.
Elevation:.
Location:
KAB
+/-304'
Carlsbad
Ol
o
I
o
GEOLOGIC
ATTITUDES DATE: 1/27/98 DESCRIPTION:
GEOLOGIC
UNIT
ENGINEERING PROPERTIES
USCS
Sample
No. Moist.
{%)
Density
(pcf)
TOPSOIL Topsoi1 SM/SC
@ 0-1': Brown, damp, soft, slightly clayey to clayey,
•• sand with abundant organic debris fine to medium
(roots, leaves
silty
litter, etc.)
OUATERNARY TERRACE DEPOSITS Qt SM
B @ r-4': Orange-brown, damp, very dense, silty fine to coarse
sand, massive, abundant iron-oxide staining
throughout
zr
o
3
> 0) CO o o
a
CD CO
GRAPHIC REPRESENTATION: N.W. Wall SCALE: 1" =5' SURFACE SLOPE: 2°SE TREND: N85°E
llll llll llll llll llll llll 4-M-
TOTAL DEPTH AT 4'
NO GROUND WATER
ENCOUNTERED
BACKFILLED: 1/27/95
LOG OF TRENCH NO.: T-4
cn o
>
I
CO
o
Project Name: Poinsettia Village
Project Number:.
Equipment: 4980005-001
JD 710 4X4 Backhoe
Logged by:
Elevation:
Location:
KAB
+/-290'
Carlsbad
GEOLOGIC
ATTITUDES DATE: 1/27/98 DESCRIPTION:
GEOLOGIC
UNIT
ENGINEERING PROPERTIES
USCS
Sample
No.
Moist.
{%)
Density
(pcf)
(Q*
or
o
3
> CO CO o o
tt"
<-» (D CO
TOPSOIL
A (a 0-1': Dark brown, moist, soft, slightly clayey to clayey
silty fine sand; abundant organics
QUATERNARY COLLUVIUM
B @ r-5': Light brown, moist, soft to medium dense, slightly
clayey, silty. fine to medium sand; weakly visible
bedding
@ +5': Perched ground water
TERTIARY SCRIPPS FORMATION
C (a 5'-10': Light yellow-brown, moist, to slightly moist,
dense, silty, fine to medium sandstone
Topsoi1
Qcol
SM/CL
SM
T-4#l
@6'-8'
Tsc SM
GRAPHIC REPRESENTATION: E. Face SCALE: 1" =5' SURFACE SLOPE: 10°SE TREND: N.S.
LOG OF TRENCH NO.: T-5
Ol
o
I
>
CO
o
Project Name: Poinsettia Village
Project Number:.
Equipment: 4980005-001
JD 710 4X4 Backhoe
Logged by:
Elevation:
Location:
KAB
+/-285'
Carlsbad
GEOLOGIC
ATTITUDES DATE: 1/27/98 DESCRIPTION:
GEOLOGIC
UNIT
ENGINEERING PROPERTIES
USCS
Sample
No.
Moist.
{%)
Density
(pcf)
WEATHERED TERRACE
@ 0-r orange-brown, damp, soft to loose, clayey, silty,
to coarse sand with abundant organic material
Dark orange
fine
OUATERNARY TERRACE
Qt
Qt
SM-SC
SM-SC
(D
>
CO o o
5"
(D 0)
B (a r-7': Orange-brown, damp to moist, medium dense to dense.
clayey fine to coarse sand; massive scattered
manganese-oxide staining
TERTIARY SCRIPPS FORMATION
C (a 7'-9': Light brown to gray, damp, very dense, silty fine
to medium sand; massive with scattered manganese-
staining and nodules
T-5
#1 @
2'-4'
GRAPHIC REPRESENTATION: N.W. Wall SCALE: 1" =5' SURFACE SLOPE: 5°S TREND: N10°E
LOG OF TRENCH NO.: T-6
cn o
I
>
CO
o
Project Name: Poinsettia Village
Project Number: 4980005-001
Equi pment: JD 710 4X4 Backhoe
Logged by:.
Elevation:.
Location:
KAB
+/-298'
Carlsbad
GEOLOGIC
ATTITUDES DATE: 1/27/98 DESCRIPTION:
GEOLOGIC
UNIT
ENGINEERING PROPERTIES
USCS
Sample
No.
Moist.
{%)
Density
(pcf)
ARTIFICIAL FILL - UNDOCUMENTED
A @ 0-2': Light brown, moist, soft to loose, slightly clayey,
silty fine to medium sand
TERTIARY SCRIPPS FORMATION
B @ 2'-5': Light greenish gray, damp, very dense, slightly
silty fine to medium sandstone
Afu SM
Tsc SM
(0
(Q*
3"
o
3
>
CO 0> O -
o
tt'-CO CO
GRAPHIC REPRESENTATION: SCALE: 1" = 5' SURFACE SLOPE: 0° TREND: N80°W
llll llll llll UI-4-I I I I llll llll llll
TOTAL DEPTH AT 5'
NO GROUND WATER
ENCOUNTERED
BACKFILLED: 1/27/98
LOG OF TRENCH NO.: T-7
CJl o
I
>
CD O
Project Name: Poinsettia Village
Project Number:
Equipment: 4980005-001
JD 710 4X4 Backhoe
Logged by:.
Elevation:.
Location:
KAB.
+/-306'
Carlsbad
GEOLOGIC
AHITUDES DATE: 1/27/98 DESCRIPTION:
GEOLOGIC
UNIT
ENGINEERING PROPERTIES
USCS
Sample
No.
Moist.
{%)
Density
(pcf)
TOPSOIL
A (a 0'-2' Dark brown, damp to moist, loose to soft, slightly
clayey, silty, fine to medium sand
TERTIARY SCRIPPS FORMATION
B @ 2'-4': Light gray-green, damp, very dense, silty, fine to
medium sandstone; with abundant iron-oxide
staining, massive
Topsoi1
Tsc
SM-CL
SM
(D
3"
o
3
po
CO o o
a
CO Cli
GRAPHIC REPRESENTATION: N.W. Wall SCALE: 1" =5' SURFACE SLOPE: TREND: N80°E
llll llll llll llll llll llll llll
TOTAL DEPTH AT 4'
NO GROUND WATER
ENCOUNTERED
BACKFILLED: 1/27/98
LOG OF TRENCH NO.: T-8
CJl o
I
>
CO
o
Project Name: Poinsettia Village
Project Number: 4980005-001
Equi pment: JD 710 4X4 Backhoe
Logged by:.
Elevation:.
Location:
KAB
+/-290'
Carlsbad
GEOLOGIC
ATTITUDES DATE: 1/27/98 DESCRIPTION:
GEOLOGIC
UNIT
ENGINEERING PROPERTIES
USCS
Sample
No.
Moist.
{%)
Density
(pcf)
(D
ci'
3^
o
3
> 0) CO o o
»•
<D CO
TOPSOIL
A (a 0-1': Brown, moist, loose to soft, slightly clayey, silty,
fine to coarse sand
OUATERNARY TERRACE DEPOSITS
B (a r-4': Orange-brown, damp to moist, dense, slightly clayey,
silty. fine to coarse sand
TERTIARY SCRIPPS FORMATION
C (a 4'-5': Light greenish-gray, damp to moist, slightly clayey,
silty. fine to medium sandstone
Topsoi1
Qt
Tsc
SM-CL
SC-SM
SM
GRAPHIC REPRESENTATION: S.E. Wall SCALE: 1" = 5' SURFACE SLOPE: 10°NE TREND: N20°E
•4—^4-llll llll 4-M-•4-4-4-4-llll llll llll
TOTAL DEPTH AT 5'
NO GROUND WATER
ENCOUNTERED
BACKFILLED: 1/27/98
LOG OF TRENCH NO.: T-9
Project Name: Poinsettia Village
Project Number: 4980005-001
Equi pment: JD 710 4X4 Backhoe
Logged by:.
Elevation:.
Location:
KAB
-H/-237'
Carlsbad
CJl
p
>
CO
o
GEOLOGIC
ATTITUDES DATE: 1/27/98 DESCRIPTION:
GEOLOGIC
UNIT
ENGINEERING PROPERTIES
USCS
Sample
No.
Moist.
{%)
Density
(pcf)
QUATERNARY ALLUVIUM
A @ 0-2.5' Light brown, moist to wet. unconsolidated silty fine
to coarse sand; abundant roots and organic debris
ARTIFICIAL FILL (documented)
B (a 2.5'-15': Light brown to dark brown, damp to moist (wet at
contact with Qal), medium dense, slightly clayey,
silty, fine to medium sand; scattered organic
debris and moderate organic (decomposing) odor,
lifts vary in thickness, where visible, from
8"-10"
Qal
Afd
SM
SM
CD Si or
o
3
> OB CO O o 53'
CO 09
GRAPHIC REPRESENTATION: N.E. Wall SCALE: 1" = 5' SURFACE SLOPE: 2°S TREND: N°W
4980005-002
APPENDIX C
Laboratorv Testing Procedures and Test Results
Direct Shear Tests: Direct shear tests were performed on selected remolded and/or undisturbed samples
which were soaked for a minimum of 24 hours under a surcharge equal to the applied normal force during
testing. After transfer of the sample to the shear box, and reloading the sample, pore pressures set up in the
sample due to the transfer were allowed to dissipate for a period of approximately 1 hour prior to
application of shearing force. The samples were tested under various normal loads, a motor-driven, strain-
controlled, direct-shear testing apparatus at a strain rate of less than 0.001 to 0.5 inches per minute
(depending upon the soil type). The test results are presented in the test data.
Sample
Location
Sample Description Friction Angle
(degrees)
Apparent Cohesion
(psO
B-2, #2 Light brown, silty sand 37 580
B-2, #3 Light brown, silty sand 43 225
T-5,#l Reddish-brown, silty sand
(remolded)
36 150
Expansion Index Tests: The expansion potential of selected materials was evaluated by the Expansion
Index Test, U.B.C. Standard No. 18-2. Specimens are molded under a given compactive energy to
approximately the optimum moisture content and approximately 50 percent saturation or approximately 90
percent relative compaction. The prepared 1-inch thick by 4-inch diameter specimens are loaded to an
equivalent 144 psf surcharge and are inundated with tap water until volumetric equilibrium is reached. The
results of these tests are presented in the table below:
Sample
Location
Sample Description Expansion
Index
Expansion
Potential
T-4,#l Light brown, silty sand 0 Very low
T-5,#l Reddish-brown, silty sand 0 Very low
B-4, #5A Greenish gray, silty clay to clayey silt 102 High
B-5,#1A Greenish-gray, silty clay to clayey
silt
108 High
Moisture and Densitv Determination Tests: Moisture content and dry density determinations were
performed on relatively undisturbed samples obtained from the test borings and/or trenches. The results of
these tests are presented in the boring and/or trench logs. Where applicable, only moisture content was
determined from "undisturbed" or disturbed samples.
C-1
4980005-002
Laboratorv Testing Procedures (Continued)
Maximum Densitv Tests: The maximum dry density and optimum moisture content of typical materials
were determined in accordance with ASTM Test Method D1557. The results of these tests are presented in
the table below:
Sample Location Sample Description
Maximum Dry
Density (pcf)
Optimum Moisture
Content (%)
T-5,#l Reddish-brown, slightly clayey,
silty sand (Terrace Material)
126.5 9.6
Minimum Resistivitv and pH Tests: Minimum resistivity and pH tests were performed in general
accordance with Califomia Test Method 643. The results are presented in the table below:
Sample Location
Sample
Description pH Minimum Resistivity (ohms-cm)
B-4, #5 Olive-green, silty clay 6.3 2400
T-4,#l Light tan, silty sand 7.1 5100
T-5,#l Reddish-brown, silty sand 5.8 12,600
Soluble Sulfates: The soluble sulfate contents of selected samples were determined by standard
geochemical methods. The test results are presented in the table below:
Sample Location Sample Description
Sulfate Content
(ppm)
Potential Degree of
Sulfate Attack*
B-4, #5 Olive-green, silty clay 50 Negligible
T-4, #1 Light tan, silty sand 50 Negligible
T-5,#l Reddish-brown, silty sand <50 Negligible
* Based on the 1997 edition of the Uniform Building Code, Table No. 19-A-7, prepared by the
Intemational Conference of Building Officials (ICBO, 1997).
C-2
Leighton and Associates, Inc.
GENERAL EARTHWORKAND GRADING SPECIFlCAtiONS
Page 1 of 6
LEIGHTON AND ASSOCIATES, INC.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS FOR ROUGH GRADING
1.0 General
1.1 Intent These General Earthwork and Grading Specifications are for the grading and
eaithwork showTi on the approved grading plan(s) and/or indicated in the geotechnical
report(s). These Specifications are a part of the recommendations contained in the
geotechnical report(s). In case of conflict, the specific recommendations in the
geotechnical report shall supersede these more general Specifications. Observations of the
earthwork by the project Geotechnical Consultant during the course of grading may result
in new or revised recommendations that could supersede these specifications or the
recommendations in the geotechnical report(s).
1.2 The Geotechnical Consultant of Record: Prior to commencementofwork, the owner shall
employ the Geotechnical Consultant of Record (Geotechnical Consultant). The
Geotechnical Consultants shall be responsible for reviewing the approved geotechnical
report(s) and accepting the adequacy of the preliminary geotechnical findings, conclusions,
and recommendations prior to the commencementof the grading.
Prior to commencement of grading, the Geotechnical Consultant shall review the "work
plan" prepared by the Earthwork Contractor (Contractor) and schedule sufficient personnel
to perform the appropriate level of observation, mapping, and compaction testing.
During the grading and earthwork operations, the Geotechnical Consultant shall observe,
map, and document the subsurface exposures to verify the geotechnical design
assumptions. If the observed conditions are found to be significantly different than the
interpreted assumptions during the design phase, the Geotechnical Consultant shall inform
the owner, recommend appropriate changes in design to accommodate the observed
conditions, and notify the review agency where required. Subsurface areas to be
geotechnically observed, mapped, elevations recorded, and/or tested include natural ground
after it has been cleared for receiving fill but before fill is placed, bottoms of all "remedial
removal" areas, all key bottoms, and benches made on sloping ground to receive fill.
The Geotechnical Consultant shall observe the moisture-conditioningand processing of the
subgrade and fill materials and perform relative compaction testing of fill to determine the
attained level of compaction. The Geotechnical Consultant shall provide the test results to
the owner and the Contractor on a routine and frequent basis.
Leighton and Associates, Inc.
GENERAL EARTHWORKAND GRADING SPECIFICATIONS
Page 2 of 6
1.3 The Earthwork Contracton The Earthwork Contractor (Contractor) shall be qualified,
experienced, and knowledgeable in earthwork logistics, preparation and processing of
ground to receive fill, moisture-conditioningand processing of fill, and compacting fill.
The Contractor shall review and accept the plans, geotechnical report(s), and these
Specifications prior to commencement of grading. The Contractor shall be solely
responsible for performing the grading in accordance with the plans and specifications.
The Contractor shall prepare and submit to the owner and the Geotechnical Consultant a
work plan that indicates the sequence of earthwork grading, the number of "spreads" of
work and the estimated quantities of daily earthwork contemplated for the site prior to
commencement of grading. The Contractor shall inform the owner and the Geotechnical
Consultant of changes in work schedules and updates to the work plan at least 24 hours in
advance of such changes so that appropriate observations and tests can be planned and
accomplished. The Contractor shall not assume that the Geotechnical Consultant is aware
of all grading operations.
The Contractor shall have the sole responsibility to provide adequate equipment and
methods to accomplish the earthwork in accordance with the applicable grading codes and
agency ordinances, these Specifications, and the recommendations in the approved
geotechnical report(s) and grading plan(s). If, in the opinion of the Geotechnical
Consultant, unsatisfactory conditions, such as unsuitable soil, improper moisture condition,
inadequate compaction, insufficient buttress key size, adverse weather, etc., are resulting in
a qualify of work less than required in these specifications, the Geotechnical Consultant
shall reject the work and may recommend to the owner that constmction be stopped until
the conditions are rectified.
2.0 Preparation of Areas to be Filled
2.1 Clearing and Gmbbing: Vegetation, such as bmsh, grass, roots, and other deleterious
material shall be sufficiently removed and properly disposed of in a methcxl acceptable to
the owner, goveming agencies, and the Geotechnical Consultant.
The Geotechnical Consultant shall evaluate the extent of these removals depending on
specific site conditions. Earth fill material shall not contain more than 1 percent of organic
materials (by volume). No fill lift shall contain more than 5 percent of organic matter.
Nesting of the organic materials shall not be allowed.
If potentially hazardous materials are encountered, the Contractor shall stop work in the
affected area, and a hazardous material specialist shall be informed immediately for proper
evaluation and handling of these materials prior to continuing to work in that area.
As presently defined by the State of Califomia, most refined petroleum products (gasoline,
diesel fiiel, motor oil, grease, coolant, etc.) have chemical constituents that are considered
to be hazardous waste. As such, the indiscriminate dumping or spillage of these fluids
onto the ground may constitute a misdemeanor, punishable by fines and/or imprisonment,
and shall not be allowed.
Leighton and Associates, Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 3 of 6
2.2 Processing: Existing ground that has been declared satisfactory for support of fill by the
Geotechnical Consultant shall be scarified to a minimum depth of 6 inches. Existing
ground that is not satisfactory shall be overexcavated as specified in the following section.
Scarification shall continue until soils are broken down and free of large clay lumps or
clods and the working surface is reasonably uniform, flat, and free of uneven features that
would inhibit uniform compaction.
2.3 Overexcavation In addition to removals and overexcavations recommended in the
approved geotechnical report(s) and the grading plan, soft, loose, dry, saturated, spongy,
organic-rich, highly fractured or otherwise unsuitable ground shall be overexcavated to
competent ground as evaluated by the Geotechnical Consultant during grading.
2.4 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal
to vertical units), the ground shall be stepped or benched. Please see the Standard Details
for a graphic illustration. The lowest bench or key shall be a minimum of 15 feet wide and
at least 2 feet deep, into competent material as evaluated by the Geotechnical Consultant.
Other benches shall be excavated a minimum height of 4 feet into competent material or as
otherwise re(x>mmended by the Geotechnical Consultant. Fill placed on ground sloping
flatter than 5:1 shall also be benched or otherwise overexcavated to provide a flat subgrade
for the fill.
2.5 Evaluation/Acceptance of Fill Areas: All areas to receive fill, including removal and
processed areas, key bottoms, and benches, shall be observed, mapped, elevations recorded,
and/or tested prior to being accepted by the Geotechnical Consultant as suitable to receive
fill. The Contractor shall obtain a written acceptance fi-om the Geotechnical Consultant
prior to fill placement. A licensed surveyor shall provide the survey control for
determiningelevationsof processed areas, keys, and benches.
3.0 Fill Material
3.1 General: Material to be used as fill shall be essentially fi-ee of organic matter and other
deleterious substances evaluated and accepted by the Geotechnical Consultant prior to
placement. Soils of poor qualify, such as those with unacceptable gradation, high
expansion potential, or low strength shall be placed in areas acceptable to the Geotechnical
Consultant or mixed with other soils to achieve satisfactory fill material.
3.2 Oversize: Oversize material defined as rock, or other irreducible material with a maximum
dimension greater than 8 inches, shall not be buried or placed in fill unless location,
materials, and placement methods are specifically accepted by the Geotechnical Consultant.
Placement operations shall be such that nesting of oversized material does not occur and
such that oversize material is completely surrounded by compacted or densified fill.
Oversize material shall not be placed within 10 vertical feet of finish grade or within 2 feet
of fiiture utilities or underground constmction.
3.3 Import If importing of fill material is required for grading, proposed import material shall
meet the requirements of Section 3.1. The potential import source shall be given to the
3030.1094
Leighton and Associates, Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 4 of 6
Geotechnical Consultant at least 48 hours (2 working days) before importing begins so that
its suitabilify can be determined and appropriate tests performed.
4.0 Fill Placement and Compaction
4.1 Fill Layers: Approved fill material shall be placed in areas prepared to receive fill (per
Section3.0) in near-horizontal layers not exceeding 8 inches in loose thickness. The
Geotechnical Consultant may accept thicker layers if testing indicates the grading
procedures can adequately compact the thicker layers. Each layer shall be spread evenly
and mixed thoroughly to attain relative uniformifyof material and moisture throughout.
4.2 Fill Moisture Conditioning: Fill soils shall be watered, dried back, blended, and/or mixed,
as necessary to attain a relatively uniform moisture content at or slightly over optimum.
Maximum densify and optimum soil moisture content tests shall be performed in
accordance with the American Sociefy of Testing and Materials (ASTM Test Method
D1557-91).
4.3 Compaction of Fill: After each layer has been moistur6KX)nditioned, mixed, and evenly
spread, it shall be uniformly compacted to not less than 90 percent of maximum dry densify
(ASTM Test Method D1557-91). Compaction equipment shall be adequately sized and be
either specifically designed for soil compaction or of proven reliabilify to efficiently
achieve the specified level of compaction with uniformify.
4.4 Compaction of Fill Slopes: In addition to normal compaction procedures specified above,
compaction of slopes shall be accomplished by backrolling of slopes with sheepsfoot
rollers at increments of 3 to 4 feet in fill elevation, or by other methods producing
satisfactory results acceptable to the Geotechnical Consultant. Upon completion of
grading, relative compaction of the fill, out to the slope face, shall be at least 90 percent of
maximum densify per ASTM Test Method D1557-91.
4.5 Compaction Testing: Field tests for moisture content and relative compaction of the fill
soils shall be performed by the Geotechnical Consultant. Location and frequency of tests
shall be at the Consultant's discretion based on field conditions encountered. Compaction
test locations will not necessarily be selected on a random basis. Test locations shall be
selected to verify adequacy of compaction levels in areas that are judged to be prone to
inadequate compaction (such as close to slope faces and at the fill/bedrock benches).
4.6 Frequency of Compaction Testing: Tests shall be taken at intervals not exceeding 2 feet in
vertical rise and/or 1,000 cubic yards of compacted fill soils embankment. In addition, as a
guideline, at least one test shall be taken on slope faces for each 5,000 square feet of slope
face and/or each 10 feet of vertical height of slope. The Contractor shall assure that fill
constmction is such that the testing schedule can be accomplished by the Geotechnical
Consultant. The Contractor shall stop or slow down the earthwork constmction if these
minimum standards are not met.
3030.1094
Leighton and Associates, Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 5 of 6
4.7 Compaction Test Locations: The Geotechnical Consultant shall document the approximate
elevation and horizontal coordinates of each test location. The Contractor shall coordinate
with the project surveyor to assure that sufficient grade stakes are established so that the
Geotechnical Consultant can determine the test locations with sufficient accuracy. At a
minimum, two grade stakes within a horizontal distance of 100 feet and vertically less than
5 feet apart from potential test locations shall be provided.
5.0 Subdrain Installation
Subdrain systems shall be installed in accordance with the approved geotechnical report(s), the
grading plan, and the Standard Details. The Geotechnical Consultant may recommend additional
subdrains and/or changes in subdrain extent, location, grade, or material depending on conditions
encountered during grading. All subdrains shall be surveyed by a land surveyor/civil engineer for
line and grade after installation and prior to burial. Sufficient time should be allowed by the
Contractor for these surveys.
6.0 Excavation
Excavations, as well as over-excavation for remedial purposes, shall be evaluated by the
Geotechnical Consultant during grading. Remedial removal depths shown on geotechnical plans
are estimates only. The actual extent of removal shall be determined by the Geotechnical
Consultant based on the field evaluation of exposed conditions during grading. Where fill-over-cut
slopes are to be graded, the cut portion of the slope shall be made, evaluated, and accepted by the
Geotechnical Consultant prior to placement of materials for constmction of the fill portion of the
slope, unless otherwise recommended by the Geotechnical Consultant.
7.0 Trench Backfills
7.1 The Contractor shall follow all OHSA and Cal/OSHA requirements for safefy of trench
excavations.
7.2 All bedding and backfill of utilify trenches shall be done in accordsmce with the applicable
provisions of Standard Specifications of Public Works Constmction. Bedding material
shall have a Sand Equivalent greater than 30 (SE>30). The bedding shall be placed to 1
foot over the top of the conduit and densified by jetting. Backfill shall be placed and
densified to a minimum of 90 percent of maximum from 1 foot above the top of the conduit
to the surface.
7.3 The jetting of the bedding around the conduits shall be observed by the Geotechnical
Consultant.
7.4 The Geotechnical Consultant shall test the trench backfill for relative compaction. At least
one test should be made for evety 300 feet of trench and 2 feet of fill.
3030.1094
Leighton and Associates, Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 6 of 6
7.5 Lift thickness of trench backfill shall not exceed those allowed in the Standard
Specifications of Public Works Constmction unless the Contractor can demonstrate to the
Geotechnical Consultant that the fill lift can be compacted to the minimum relative
compaction by his altemative equipment and method.
3030.1094
I
I
PROJECrrED PtANC
1 TO 1 lylAXIMUM FROM TOE
OF SLOPE TO APPROVED GOOUND
NATURAL
GROUND
_ jrZ^X^MPACTED^Tir:
2'MIN.
KEY DEPTH
. MIN.-^~
U—15' MiN.
LOWEST BENCH
(KEY)
4'TYPK:AL
BENCHI t
-—— "^^r —' FILL SLOPE
REMOVE
UNSUITABLE
MATERIAL
BENCH
HEKSHT
??PMPACTEO~^^i:n FILL-OVER-CUT
SLOPE
NATURAL
GROUND
•ir MW.—H
LOWEST BENCH*
— 2'MIN.
KEY DEPTH
4'TYPK:AL
BENCH
HEK3HT
REMOVE
UNSUITABLE
MATERIAL
CUT FACE
SHALL BE CONSTRUCTS} PRK3R
TO FRJL PlACEMB4fT TO ASSURE
ADEQUATE (SEOLOOK CONOnXSNS
OUTFACE
TO BE CONSTRUCTED PRIOR
TO FILL PLACByiENr\
NATURAL
QROUND
OVERBUILT AND
TRIM BACK
PROJECTED PLANE
1 TOI MAXIMUM FROM
TOEOF8U3PETO
APPROVED GROUND^
DESK2N SLOPE REMOVE
NSUITABLE
MATERIAL
CUT-OVER-FILL
SLOPE
For Subdrains See
Standard Detail C
2' MIN.--J
KEY DEPTH
BENCH HEIGHT
I LOWEST BENCH
(Ken
Sa^GHINQ SHAa BE DONE WHEN SLOPES
ANGLE IS eOUAL TO OR GREATER THAN 5:1
MINMUM BB4CH HEIQHT SHALL BE 4 FEET
MINIMUM FNJ. WIDTH SHALL BE 9 FEET
KEYING AND BENCHING GENERAL EARTHWORK AND GRADING
SPECIFICATIONS
STANDARD DETAILS A
REV. 4^ 1/96
FINISH GRADE
SLOPE
FACE
-IO' MIN.^r~:COMPACTED FILL_---zr^
^^^^^^^
^5lHrEH*lWIN.2^
;£^?5--0VERSIZE --^-^-^-^-^-^-^-^
r-_rtr^IWINDROW
• Ovefsbe rock Is larger than 8 inches
In largest dimensioa
• Excavate a trench fti the compacted
fill deep enough to bury all the rock.
-^S• MIN.'
JETTED OR FLOODED
GRANULAR MATERIAL
• Backfin Wtth granular soil jetted or
fkxxled In place to fin all the vokls.
• Oo not bury rock within 10 feet of
finish grade.
• Windrow of buried rock shaH be
parallel to the fhished stope m. ELEVATION A-A'
PROFILE ALONG WINDROW
A
JETTED OR FLOODED
GRANULAR MATERIAL
OVERSIZE
ROCK DISPOSAL
GENERAL EARTHWORK AND GRADING
SPECIFICATIONS
STANDARD DETAILS B
4/95
NATURAL
GROUND
REMOVE
UNSUITABLE
MATERIAL
MIN. OVERLAP FROM THE TOP
HOG RING TIED EVERY 6 FEET
CALTRANS CLASS II
PERMEABLE OR #2 ROCK'
(9FT.»/FT.) WRAPPED IN
FILTER FABRIC
APPROVED
EQUIVALENT)
CANYON SUBDRAIN OUTLET DETAIL
FILTER FABRIC
(MIRAF1140 ORv
APPROVED \ COLLECTOR PIPE SHALL
DESIGN
FINISHED
GRADE
PERFORATED PIPE
6-<^ MIN.
BE MINIMUM 6* DIAMETER
SCHEDULE 40 PVC PERFORATED
PIPE. SEE STANDARD DETAIL D
FOR PIPE SPECIFICATION
20' MIN
.NON-PERFORATED
6-^ MIN. 5' MIN.
FILTER FABRIC
(MIRAFI 140 OR
APPROVED
EQUIVALENT)
#2 ROCK WRAPPED IN FILTER
FABRIC OR CALTRANS CLASS II
PERMEABLE.
CANYON SUBDRAINS GENERAL EARTHWORK AND GRADING
SPECIFICATIONS
STANDARD DETAILS C
4/95
OUTLET PIPES
4"<|> NON-PERFORATED PIPE,
100' MAX. O.C. HORIZONTALLY,
30' MAX. O.C. VERTICALLY BACKCUT 1:1
OR FLATTER
KEY j-
DEPTH 1
1
2' MIN
POSITIVE SEAL
SHOULD BE
PROVIDED AT
THE JOI
12- MIN. OVERLAP FROM THE TOP
HOG RING TIED EVERY 6 FEET
\
FILTER FABRIC
(MIRAF1140 OR
APPROVED
EQUIVALENT)
T-CONNECTION FOR
COLLECTOR PIPE TO
OUTLET PIPE
OUTLET PIPE
(NON-PERFORATED)
CALTRANS CLASS II
PERMEABLE OR #2 ROCK
(3FT.'/FT.) WRAPPED IN
FILTER FABRIC
• SUBDRAIN INSTALLATION • Subdrain collector pipe shall be instaiied with perforatkms down or,
unless otherwise designated by the geotechnteal consultant Outlet pipes shall be non-perforated
pipe. The subdrain pipe shall have at least 8 pe(fbratk)ns uniformly spaced per foot Perforatkxi sfiall
be y*' to %' If drilled holes are used. All subdrain pipes shall have a gradient at least 2% towards the
outlet
• SUBDRAIN PIPE - Subdrain pipe shall be ASTM D2751, SDR 23.5 or ASTM D1527, Scheduie 40, or
ASTM D3034, SDR 23.5, Schedule 40 Polyvinyl Chk>rkle Plastk; (PVC) pipe.
• All outlet pipe shall be placed in a trench no wider than twtoe the subdrain pipe. Pipe shall be in soil
of SE>,30 jetted or fiooded in place except for the outside 5 feet whteh shall be native soii backfill.
BUTTRESS OR
REPLACEMENT FILL
SUBDRAINS
GENERAL EARTHWORK AND GRADING
SPECIFICATIONS
STANDARD DETAILS D
4/95
RETAINING WALL DRAINAGE DETAIL
-SOIL BACKFILL, COMPACTED TO
90 PERCENT RELATIVE COMPACTION*
RETAINING WALL
WALL WATERPROOFING
PER ARCHITECf'S
SPECIFib ATIONS^
FINISH GRADE
"=ilHH:^^*OMPACTED FILL|:~~~-
0 6" MIN. P
PVE^RLAP
0 00/
0 «
1' MIN.
WALL FOOTING Ol
NOT TO SCALE
FILTER FABRIC ENVELOPE
(MIRAFI 140N OR APPROVED
EQUIVALENT)**
**
SPECIFICATIONS FOR CALTRANS
CLASS 2 PERMEABLE MATERIAL
U.S. Standard
Sieve Size % Passing
1" 100
3/4" 90-100
3/8" 40-100
No. 4 25-40
No. 8 18-33
No. 30 5-15
No. 50 0-7
No. 200 0-3
Sand Equivalent>75
-3/4'-1-1/2" CLEAN GRAVEL
4'<MIN.^PIAMETER PERFORATED
PVC PIPETSCHEDULE 40 OR
EQUIVALENT) WITH PERFORATIONS
ORIENTED DOWN AS DEPICTED
MINIMUM 1 PERCENT GRADIENT
TO SUITABLE OUTLET
3' MIN.
COMPEf^ENT BEDROCK OR MATERIAL
AS EVALUATED BY THE GEOTECHNICAL
CONSULTANT
•BASED ON ASTM D1557
**IF CALTRANS CLASS 2 PERMEABLE MATERIAL
(SEE GRADATION TO LEFT) IS USED IN PLACE OF
3/4'-1-1/2' GRAVEL, FILTER FABRIC MAY BE
DELETED. CALTRANS CLASS 2 PERMEABLE
MATERIAL SHOtH.D BE COMPACTED TO SQ
PERCENt?RELATlVE COMPACTION *
NOTE:COMPOSiTE DRAINAGE PRODUCTS SUCH AS MIRADRAIN
OR J-DRAIN MAY BE USED AS AN ALTERNATIVE TO GRAVEL OR
CLASS Z INSTALLATION SHOULD BE PSRFORMED IN ACCORDANCE
WITH MANUFACTURER'S SPECIRCATKDNa
4980005-001
APPENDIX E
STABILITY ANALYSIS FOR HOMOGENEOUS EARTH SLOPES
Design Parameters and Assumptions
Type of Slope: Cut slope
Type of Soil Materials: Terrace Deposits/Scripps Formation
H = Height of Slope = 25 feet
/3 = Angle of Slope = 26 degrees
7, = Total (wet) Unit Weight = 135 pcf
<t) = Angle of Internal Friction = 37 degrees
C = Cohesion = 225 psf
• No seepage forces
• Total shear strength parameters are used in lieu of effective strength
Analvsis
Y, • ^ • tan (j)
Dimensionless Parameters = X. = —^ =11
CJ y-l
Stability Number (from Figure 10 of Reference 2) = N , = 35
Minimum Factor of Safety = F.S. j = • —^ =2.3 (> 1.5 O.K.) C_
References
1. Bell, J.M., Dimensionless Parameters for Homogeneous Earth Slopes, Journal, Soil Mechanics
and Foundation Division, American Society of Civil Engineers, No. SMS, September
1966.
2. Janbu, N., Discussion for (Reference - 1), Joumal. Soil Mechanics and Foundation Division,
American Society of Civil Engineers, No. SSM6, November 1967.
4980005-001
STABILITY ANALYSIS FOR HOMOGENEOUS EARTH SLOPES (CONTINUED)
Design Parameters and Assumptions
Type of Slope: Fill Slope
Type of Soil Materials: Derived from Onsite Terrace/Scripps Formation
H = Height of Slope = 55 feet
/3 = Angle of Slope = 26 degrees
7, = Total (wet) Unit Weight = 135 pcf
</> = Angle of Internal Friction = 36 degrees
C = Cohesion = 150 psf
• No seepage forces
• Total shear strength parameters are used in lieu of effective strength
Analvsis
y-H-tan<\> Dimensionless Parameters = A. - = = 36 ^ C
Stability Number (from Figure 10 of Reference 2) = N^j. = 90
Minimum Factor of Safety = F.S. (^i„) = • —^ = 1.8 (> 1.5 O.K.) C_
References
1. Bell, J.M., Dimensionless Parameters for Homogeneous Earth Slopes, Joumal. Soil Mechanics and
Foundation Division, American Society of Civil Engineers, No. SM5, September 1966.
2. Janbu, N., Discussion for (Reference - 1), Journal. Soil Mechanics and Foundation Division,
American Society of Civil Engineers, No. SSM6, November 1967.
E-2
4980005-001
APPENDIX E (continued)
SURFICIAL SLOPE STABILITY ANALYSIS
Fill Slope
Derived from Terrace Deposits/Scripps Formation
ASSUMED PARAMETERS
Z = Depth of Saturation = 4 ft.
/ = Slope Angle = 26 degrees
7« = Unit Weight of Water = 62.4 pcf
7, = Saturated Unit Weight of Soil = 135 pcf
</) = Apparent Angle of Intemal Friction = 36 degrees
C = Apparent Cohesion =150 pcf
^ C + otan (j) ^ C +(Y, - yJZ cos'/ tan 4>
T Y, sin /• cos i
FS = 1.5 (>: 1.5, o.k.)
E-3
4980005-001
APPENDIX E (continued)
SURFICIAL SLOPE STABILITY ANALYSIS
• Cut Slope
• Terrace Deposits/Scripps Formation
ASSUMED PARAMETERS
Z = Depth of Saturation = 4 ft.
i = Slope Angle = 26 degrees
7^ = Unit Weight of Water = 62.4 pcf
7, = Saturated Unit Weight of Soil = 135 pcf
<f> = Apparent Angle of Intemal Friction = 37 degrees
C = Apparent Cohesion = 225 pcf
^ C + otan (j) ^ C +(Y, - Y cos'' tan <i>
T Y, sin i cos i
FS = 1.9 C> 1.5, o.k.)
E-4
DATE: Wednesday, November 10, 1999
*************************************
* *
* EQFAULT *
* *
* Ver. 2.20 *
* *
* *
*************************************
(Estimation of Peak Horizontal Acceleration
From Digitized California Faults)
SEARCH PERFORMED FOR: SAC
JOB NUMBER: 980005-002
JOB NAME: Poinsettia / Aviara
SITE COORDINATES:
LATITUDE: 33.111 N
LONGITUDE: 117.294 8 W
SEARCH RADIUS: 100 mi
ATTENUATION RELATION: 3) Boore et al. (1993a) Horiz. - Random - Site Class C
UNCERTAINTY (M=Mean, S=Mean+l-Sigma): S
SCOND: 0
COMPtTTE PEAK HORIZONTAL ACCELERATION
FAULT-DATA FILE USED: CDMGSCE.DAT
SOURCE OF DEPTH VALUES (A=Attenuation File, F=Fault Data File): A
DETERMINISTIC SITE PARAMETERS
Page
ABBREVIATED
FAULT NAME
APPROX.
DISTANCE
mi (km)
MAX. CREDIBLE EVENT
MAX.
CRED.
MAG.
PEAK
SITE
ACC. g
SITE
INTENS
MM
MAX. PROBABLE EVENT
MAX.
PROB.
MAG.
PEAK
SITE
ACC. g
SITE
INTENS
MM
SAN ANDREAS - Coachella 73 118) 7.10 0 . 096 VII
VII
7.10
7.30
0.096
0.115
VII
VII SAN ANDREAS - San Bernardi
SAN ANDREAS - Southern
66
66
107)
107)
7.30
7.40
0.115
0.121 VII
VII
7.30
7.10
0.115
0.086
VII
VII SAN ANDREAS - Mojave
SAN ANDREAS - 1857 Rupture
84
84
135)
135)
7.10
7.80
0.086
0.125 VII
VI
7.50
5.90
0.107
0.045
VII
VI SUPERSTITION HILLS (San Ja
SUPERSTITION MTN. (San Jac
85
80
136)
129)
6.60
6.60
0.066
0.069 VI
VII
6.10
6.10
0.053
0.063
VI
VI SAN JACINTO - BORREGO
SAN JACINTO-COYOTE CREEK
64
51
103)
83)
6.60
6.80
0.082
0.108 VII
VIII
6.20
6.90
0.078
0.121
VII
VII SAN JACINTO-ANZA
SAN JACINTO-SAN JACINTO VA
47
49
76)
78)
7.20
6 . 90
0.142
0.119 VII
VII
6.80
6.70
0.112
0.088
VII
VII SAN JACINTO-SAN BERNARDINO
LAGtlNA SALADA
62
86
100)
139)
6.70
7.00
0.088
0.080 VII
VII
6.30
6.20
0.055
0.074
VI
VII ELSINORE-COYOTE MOUNTAIN
ELSINORE-JULIAN
55
25
89)
39)
6.80
7.10
0.102
0.223 IX
VIII
6.40
6 .30
0.154
0.146
VIII
VIII ELSINORE-TEMECULA
ELSINORE-GLEN IVY
25
37
39)
59)
6.80
6.80
0.190
0.139 VIII
VII
6.30
5.90
0.107
0.064
VII
VI WHITTIER
BRAWLEY SEISMIC ZONE
55
93
88)
150)
6.80
6.40
0.102
0.055 VI
VII
6.40
5.50
0.055
0.065
VI
VI CHINO-CENTRAL AVE. (Elsino
EARTHQUAKE VALLEY
52
42
83)
67)
6 .70
6.50
0 .123
0.108 VII
VI
5.70
5.40
0.071
0.035
VI
V ELMORE RANCH
CORONADO BANK
84
21
135)
33)
6.60
7 .40
0.066
0.297 IX
X
X
6.30
5.80
5.70
0.166
0.245
0.319
VIII
IX
IX
NEWPORT-INGLEWOOD (Offshor
ROSE CANYON
13)
8)
6 .90
6.90
0.438
0.601
Page
DETERMINISTIC SITE PARAMETERS
ABBREVIATED
FAULT NAME
APPROX.
DISTANCE
km)
MAX. CREDIBLE EVENT
MAX.
CRED.
MAG.
PEAK
SITE
ACC. g
SITE
INTENS
MM
MAX. PROBABLE EVENT
MAX.
PROB.
MAG.
PEAK
SITE
ACC. g
SITE
INTENS
MM
CLAMSHELL-SAWPIT 84 135) 6.50 0.077 VII 5.00 0.035
CUCAMONGA 74 119) 7.00 0 .109 VII 6 .10 0.068 VI
HOLLYWOOD 88 141) 6.40 0 . 070 VI 5.30 0.039
MALIBU COAST 95 154) 6.70 0.077 VII 4.90 0.030
NEWPORT-INGLEWOOD (L.A.Bas 50 80) 6.90 0.116 VII 5.60 0.058 VI
PALOS VERDES 39 63) 7.10 0.156 VIII 6.20 0 . 097 VII
RAYMOND 83 134) 6.50 0 . 077 VII 5.00 0.035
SAN JOSE 72 115) 6.50 0.086 VII 5.00 0.039
SANTA MONICA 93 149) 6 .60 0.075 VII 5.50 0.042 VI
SIERRA MADRE (San Fernando 99 159) 6.70 0.075 VII 5.60 0.042 VI
SIERRA MADRE 74 119) 7.00 0.109 VII 6.20 0.072 VI
VERDUGO 86 138) 6.70 0.083 VII 5.20 0.038
COMPTON THRUST 59 96) 6.80 0.175 VIII 5.80 0.103 VII
ELYSIAN PARK THRUST 62 100) 6.70 0.161 VIII 5.80 0.100 VII
BURNT MTN. 78 126) 6 .40 0.063 VI 5.10 0.032
CLEGHORN 80 129) 6.50 0.065 VI 6.00 0.050 VI
EUREKA PEAK 81 130) 6.40 0.061 VI 5.10 0.031
HELENDALE - S. LOCKHARDT 90 145) 7.10 0.081 VII 5.40 0.033
JOHNSON VALLEY (Northern) 96 155) 6.70 0.063 VI 5.20 0.028
LANDERS 88 142) 7.30 0.092 VII 5.20 0.030
LENWOOD-LOCKHART-OLD WOMAN 94 151) 7.30 0.088 VII 5.50 0.034
NORTH FRONTAL FAULT ZONE ( 89 143) 6.70 0.081 VII 5 .20 0 . 037
NORTH FRONTAL FAULT ZONE ( 82 133) 7.00 0.101 VII 5.60 0.048 VI
PINTO MOUNTAIN 73 118) 7.00 0.091 VII 6 .10 0.057 VI
EMERSON So. - COPPER MTN. 96 (155) 6.90 0.070 VI 5.30 0.030
*****************************************************************************
Page
-END OF SEARCH- 50 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS.
THE ROSE CANYON FAULT IS CLOSEST TO THE SITE.
IT IS ABOUT 5.0 MILES AWAY.
LARGEST MAXIMUM-CREDIBLE SITE ACCELERATION: 0.601 g
LARGEST MAXIMUM-PROBABLE SITE ACCELERATION: 0.319 g
PROBABILITY OF EXCEEDANCE vs. ACCELERATION
100 I I I I I I I I I I I I I I I I I I I I I
0.1 0.4 0.5
EXPOSURE PERIODS:
25 years 75 years
50 years 100 years
0.2 0.3
ACCELERATION (g)
BOORE ET AL. (1997) SOIL (310)
JOB No.: 980005-002
PROBABILITY OF EXCEEDANCE vs. ACCELERATION
100
0.4 0.5
EXPOSURE PERIODS:
25 years 75 years
50 years 100 years
0.2 0.3
ACCELERATION (g)
BOORE ET AL. (1997) SOIL (310)
JOB No.: 980005-002
AVERAGE RETURN PERIOD vs. ACCELERATION
1000000
D
(21
o
100000
ZD t—
LJ
<
Ct:
LU
5
LL\ 10000
CL
1000
100
10 lllllllllllllllllllllllllini II llllllllll I IIIIIIIII
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5
ACCELERATION (g)
Poinsettia / Aviara
BOORE ET AL. (1997) SOIL (310) JOB No.: 980005-002
AVERAGE RETURN PERIOD vs. ACCELERATION
1000000
1-
D
Q
O
100000
Z) I— UJ
< cr
UJ
5
10000
CL
1000
100
10 IIIIIIIII IIIIIIIII llllllllll lllll I I
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5
ACCELERATION (g)
Poinsettia / Aviara
BOORE ET AL. (1997) SOIL (310) JOB No.: 980005-002
SAN FRANCISCO
SITE LOCATION (-I-):
Latitude - 33.1110 N
Longitude - 117.2948 W
Poinsettia / Aviara
FRISKSP FAULT MAP
JOB No.: 980005-002