HomeMy WebLinkAboutRP 89-08; Beverly Centre; Redevelopment Permits (RP) (3)CASE N#_jgP_S5rB
DATE: ^
ENVIRONMENTAL IMPACT ASSESSMENT FORM - PART I
(To be Completed by APPLICANT)
Applicant: Beverly Investment Group
Address of Applicant: P.O. Box 1787
Carlsbad, CA 92008
Phone Number^:/o( 619) 454-1051
Name, address and phone number of person to be contacted (if other than
Applicant): Same as above
GENERAL INFORMATION: (Please be specific)
Project Description: The project is proposed as a 26,869 S.F. mixed
use complex encompassing retail and office uses within a three story
structure" with two levels of subterranean parkinq.
Project Location/Address: Two parcels forming the edge of the block
between State Street and Laguna Drive.
Assessor Parcel Number: 203 - lOl - 32 & 33
General Plan/Zone of Subject Property: RS, RMH/O / v-R
Local Facilities Management Zone: zone 1
Is the site within Carlsbad's Coastal Zone? Yes
Please describe the area surrounding the site to the
North: T.aanna Drive East: T.ot 203-101 "30
South: Lots 29 & 31 West: State Streec
List all other applicable permits &; approvals related to this project
Coastal Major Development and Construction
(Please be Specifj^ Attach Additional Pages or Ej^bits, if necessary)
1. Please describe the,project site, including distinguishing natural and
manmade characteristics. Also provide precise slope analysis when a slope
of 15' or higher and 15% grade or greater is present on the site.
- The site consists of two parcels and is presently being used
as the parking area for the machinery and equipment Hawthorne
- There is no slope greater than 15%.
2. Please describe energy conservation measures incorporated into the design
and/or operation of the project.
The building will have a thermal isolation of the following
ratings: R-30 for the roof and R-19 for* the walls. Use of
dual glazed windows will be considered where required by
Title 24 calculations.
3. PLEASE AHACH A PROJECT SUMMARY SHEET WHICH SHOWS THE FOLLOWING:
a. If a residential project identify the number of units, type of units,
schedule of unit sizes, range of sale prices or rents, and type of
household size expected, average daily traffic generation (latest SANDAG
rates).
N/A
b. If a commercial project, indicate the exact type, activity(ies),
square footage of sales area, average daily traffic generation
(latest SANDAG rates), parking provided, and loading facilities.
Retail: 7,120:1000 x 40 = 285
Office: 368
Total: ADT 653
Total Parking provided 88
c. If an industrial project, indicate the exact type or industry(ies),
average daily traffic generation (latest SANDAG rates), estimated
employment per shift, time of shifts, and loading facilities.
N/A
d. If an institutional project, indicate the major project/site
function, estimated employment per shift, estimated occupancy,
loading facilities, and community benefits to be derived from the
project.
N/A
I. ENVIRONMENTAL IMPACT ANALYSIS
Please Answer each of the following questions by placing a check in the
appropriate space. Then, fully discuss and explain why each item was
checked yes or no. Provide supporting data if applicable. Attach
additional sheets as necessary.
YES NO
1) Could the project significantly impact or change
present or future land u^es in the vicinity of the
activity?
EXPLANATION: The project is compatible with
the designated uses in the qeneral plan.
2) Could the activity affect the use of a recreational
area, or area of aesthetic value? x_
EXPLANATION: The development is located in
the redevelopment area in downtown Carlsbad.
3) Could the activity affect the functioning of an
established community or neighborhood? x_
EXPLANATION: No N/A
4) Could the activity result in the displacement of
community residents?
EXPLANATION: None of the uses require any
specific minimum Or maximum distance for
the communitv residents. .
X
YES NO
5) Could the activity increase the number of low and
moderate cost housing units in the city? x_
EXPLANATION: Uses, location and the magnitude
of the project do not impose any need for
additional housing of any nature. It is
intended to serve the existing population.
6) Could the activity significantly affect existing
housing or create a demand for additional housing? ^
EXPLANATION: The activities created by the
proposed project are allowed by the general
plan and zoning land use.
7) Are any of the natural or man-made features in the
activity area unique, that is, not found in other
parts of the county, state or nation? x_
EXPLANATION: The proposed uses and architecture
of the proiect are compatible with the zoning
and respect the surrounding uses and architecture.
8) Could the activity significantly affect an
historical or archaeological site or its settings? x_
EXPLANATION: The proiect is proposed for the
site within the downtown area and is currently
being used for other purposes.
9) Could the activity significantly affect the
potential use, extraction, or conservation of a
scarce natural resource? x.
EXPLANATION: Same as above.
^ YES NO
10) Could the activity significantly affect fish,
wildlife or plant resources? * ^
EXPLANATION: The proiect i.s die;tant from
the Lagoon and Riperian area.
11) Are there any rare or endangered plant or animal
species in the activity area?
EXPLANATION: Same as above.
12) Could the activity change existing features of any
of the city's stream, lagoons, bays, tidelands
or beaches? 2-
EXPLANATION: The project is far away from
the Lagoon and Floodway.
13) Could the activity result' in the erosion or elimin-
ation of agricultural lands? x_
EXPLANATION: The proiect is proposed on a city
block and is far away from agricultural
lands.
14) Could the activity serve to encourage development
of presently undeveloped areas or intensify develop-
ment of already developed areas?
EXPLANATION: The proiect is designed to fit
well in the existing citv fabric and the
uses are all compatible with the surrounding
areas.
0 YES NO
15) Will the activity require a variance from estab-
lished environmental standards (air, water, noise,
etc.)? x
EXPLANATION: The proiect design is based on
the governing standards and will not
require any variance.
16) Is the activity carried out as part of a larger
project or series of projects?
EXPLANATION: N/A
X
17) Will the activity require certification, authoriza-
tion or issuance of a permit by any local, state
or federal environmental control agency? x
EXPLANATION: All the activity within the project
is compatible with the designated land
use.
18) Will the activity require issuance of a variance or
conditional use permit by the City? x
EXPLANATION: The project is designed and
will be built respecting the limitations
set by the ordinances.
19) Will the activity involve the application, use, or
disposal of potentially hazardous materials? x
EXPLANATION: None of the uses in the proposed
design a-re of the nature to create hazardous
waste.
^ ^ YI^ NO
20) Will the-activT^ involve construction of facilities
in a flood plain? x
EXPLANATION: N/A
21) Will the activity involve construction of facilities
in the area of an active fault? x
EXPLANATION:
N/A
22) Could the activity result in the generation of
significant amounts of dust? • x.
EXPLANATION: N/A
23) Will the activity involve the burning of brush,
trees, or other materials? ^
EXPLANATION: There is no vegetation on the
site.
24) Could the activity result in a significant change
in the quality of any portion of the region's air
or water resources? (Should note surface, ground
water, off-shore.) 2_
EXPLANATION: None of the proposed uses will
result in --a. change in the quality of the
region's resources.
YES NO
25) Will the project substantially increase fuel
consumption (electricity, oil, natural gas, etc.)? x_
EXPLANATION: All the uses and the project
itself are of a nature and a magnitude
which is allowed in the zoning and by the
growth management plan.
26) Will the activity involve construction of facilities
on a slope of 25 percent or greater? x^
EXPLANATION: There are no slopes greater
than 25% on this propertv.
27) Will there be a significant change to existing
land form? x
(a) Indicate estimated grading to be done in
cubic yards: 2,753 c.Y . .
(b) Percentage of alteration to the present
land form: N/A .
(c) Maximum height of cut or fill slopes:
N/A
EXPLANATION: The project requires excavation
for an average of 18'-0" to accommodate
a two story subterranean garaqe.
28) Will the activity result in substantial increases
in the use of utilities, sewers, drains or streets? x_
EXPLANATION: All the existing utilities and
facilities are sufficient to handle the
increases.
YES NO
29) Will the project significantly increase wind or
water erosion of soils? ^
EXPLANATION: The project is located in one
of the city blocks and will have no impact
in this regard.
30) Could the project significantly affect existing
fish or wildlife habitat? x
EXPLANATION: Answered before.
31) Will the project significantly produce new light
or glare?
EXPLANATION: None of the materials proposed
are of a nature that produces a glare or
ngw light,
10
II. STATEMENT OF N(^STnNTFTrANT ENVIRQNMFNTAI FFFF^
If you have answered, yes to any of the questions in Section I but think
the activity will have no significant environmental effects, indicate your
reasonsbelow:
III. COMMENTS OR ELABORATIONS TO ANY OF THE QUESTIONS IN SECTION I
(If additional space is needed for^ answering any questions, attach
additional sheets as needed.)
Signature
(Person CompIeti
Date Signed
rig Report)
Instruct.eia
LBS:lh
11
ENVIRONMENTAL IMPACT ASSESSMENT FORM - PART H
(TO BE COMPLETED BY THE PLANNING DEPARTMENT)
BACKGROUND
1. CASE NAME: Beverly Centre
CASE NO. RP 89-8
DATE: Julv 19. 1990
2. APPLICANT: Bev Southers
3. ADDRESS AND PHONE NUMBER OF APPLICANT:
4. DATE EIA FORM PART I SUBMITTED: December 6.1989. application complete June 1. 1990
5. PROJECT DESCRIPTION: Mixed use proiect (office/retaiD: 3 storv. 28.817 square foot
structure with underground parking.
ENVIRONMENTAL IMPACTS
STATE CEQA GUIDELINES, Chapter 3, Article 5, section 15063 requires that the City conduct an
Environmental Impact Assessment to determine if a project may have a significant effect on the enviroimient.
The Environmental Impact Assessment appears in the following pages in the form ofa checklist. This checklist
identifies any physical, biological and himian factors that might be impacted by the proposed project and
provides the City with information to use as the basis for deciding whether to prepare an Enviroimiental
Impact Report or Negative Declaration.
* A Negative Declaration may be prepared if the City perceives no substantial evidence that the project or
any of its aspects may cause a significant effect on the environment. On the checklist, "NO" will be checked
to indicate this detennination.
* An EIR must be prepared if the City determines that there is substantial evidence that any aspect of the
project may cause a significant effect on the environment. The project may qualify for a Negative
Declaration however, if adverse impacts are mitigated so that environmental effects can be deemed
insignificant. These findings are shown in the checklist under the headings "YES-sig" and "YES-insig"
respectively.
A discussion of potential impacts and the proposed mitigation measures appears at the end of the form under
DISCUSSION OF ENVIRONMENTAL EVALUATION. Particular attention should be given to discussing
mitigation for impacts which would otherwise be detennined significant.
PHYSICAL ENVIRONMENT
WILL THE PROPOSAL DIRECTLY OR INDIRECTLY: YES
(sig)
YES
(insig)
NO
1. Result in unstable earth conditions or
increase the exposure of people or property
to geologic hazards?
2. Appreciably change the topography or any
unique physical features?
3. Result in or be affected by erosion of soils
either on or off the site?
4. Result in changes in the deposition of beach
sands, or modification of the channel of a
river or stream or the bed of the ocean or
any bay, inlet or lake?
5. Result in substantial adverse effects on
ambient air quality?
6. Result in substantial changes in air
movement, odor, moisture, or temperature?
7. Substantially change the course or flow of
water (marine, fresh or flood waters)?
8. Affect the quantity or quality of surface
water, ground water or public water supply?
9. Substantially increase usage or cause
depletion of any natural resources?
10. Use substantial amounts of fuel or energy?
11. Alter a significant archeological,
paieontological or historical site,
structure or object?
X
X
X
X
X
X
X
X
-2-
BIOLOGICAL ENVIRONMENT
WILL THE PROPOSAL DIRECTLY OR INDIRECTLY: YES YES NO
(sig) (insig)
12. Affect the diversity of species, habitat
or numbers of any species of plants (including
trees, shrubs, grass, microflora and aquatic
plants)? _X
13. Introduce new species of plants into an area,
or a barrier to the normal replenishment of
existing species?
14. Reduce the amount of acreage of any
agricultural crop or affect prime, unique
or other farmland of state or local
importance? X
15. Affect the diversity of species, habitat
or numbers of any species of animals (birds,
land animals, all water dwelling organisms
and insects? X
16. Introduce new species of animals into an
area, or result in a barrier to the
migration or movement of animals? X
HUMAN ENVIRONMENT
WILL THE PROPOSAL DIRECTLY OR INDIRECTLY: YES YES NO
(sig) (insig)
17. Alter the present or planned land use
of an area? X
18. Substantially affect public utilities,
schools, police, fire, emergency or other
public services?
-3-
HUMAN ENVIRONMENT
WILL THE PROPOSAL DIRECTLY OR INDIRECTLY: YES
(sig)
YES
(insig)
NO
19. Result in the need for new or modified sewer
systems, solid waste or hazardous waste
control systems?
20. Increase existing noise levels?
21. Produce new light or glare?
22. Involve a sigmficant risk of an explosion
or the release of hazardous substances
(includuig, but not limited to, oil,
pesticides, chemicals or radiation)?
23. Substantially alter the density of the
human population of an area?
24. Affect existing housing, or create a demand
for additional housing?
25. Generate substantial additional traffic?
26. Affect existing parking facilities, or
create a large demand for new parking?
27. Impact existing transportation systems or
alter present pattems of circulation or
movement of people and/or goods?
28. Alter waterbome, rail or air traffic?
29. Increase traffic hazards to motor
vehicles, bicyclists or pedestrians?
30. Interfere with emergency response plans or
emergency evacuation plans?
31. Obstruct any scenic vista or create an
aesthetically offensive public view?
32. Affect the quaHty or quantity of
existing recreational opportunities?
X
X
X
X_
X_
x_
X
-4-
MANDATORY FINDINGS OF SIGNIFICANCE
WILL THE PROPOSAL DIRECTLY OR INDIRECTLY: YES YES NO
(sig) (insig)
33. Does the project have the potential
to substantially degrade the quality
of the environment, substantially
reduce the habitat of a fish or wild-
hfe species, cause a fish or wildlife
population to drop below self-sustaining
levels, threaten to eliminate a plant or
animal community, reduce the number or
restrict the range of a rare or en-
dangered plant or animal, or eliminate
important examples of the major periods
of Califomia history or prehistory. X
34. Does the project have the potential
to achieve short-term, to the dis-
advantage of long-term, environmental
goals? (A short-term impact on the
environment is one which occurs in a
relatively brief, definitive period of
time while long-term impacts will
endure well into the future.) X
35. Does the project have the possible
environmental effects which are in-
dividually limited but cumulatively
considerable? ("Cumulatively con-
siderable" means that the incremental
effects of an individual project are
considerable when viewed in connection
with the effects of past projects, the
effects of other current projects, and
the effects of probable future projects.) X
36. Does the project have environmental
effects which will cause substantial
adverse effects on human beings,
either directly or indirectly? X
-5-
DISCUSSION QF ENVIRONMENTAL EVALUATION
The project site is the abandoned Hawthorne Equipment Rentals and Sales Facility at the
southeast comer of the intersection of State Street and Laguna drive. The five
underground fuel and waste oil tanks have been removed. The remaining improvement
is a collapsing dilapidated wood and concrete block shack. There is a block wall and no
sidewalk along the Laguna Drive frontage, which presently makes for a hazardous situation
due to inadequate sight distance and separation for pedestrian and vehicular traffic.
The proposed project is a three story grey glass and taupe stucco intemationai style
architecture retail and office building with two levels of underground parking. The parking
will be loaded off State Street as far from the intersection as possible to minimize conflict
with ttiming movements. The project will improve the Laguna frontage through additional
dedication and constmction, thereby conecting the existing deficiency.
The underground parking will necessarily require excavation. Three impacts will result
from this action. First, the site has hydrocarbon fuel contaminated soil. The removal of
and contamination remedial program for the soil is being performed in accordance with the
requirements ofthe County of San Diego Department of Health Services and the San Diego
Regional Water Quality Control Board. Second, the excavation will encounter ground
water. The stmcture and excavation will be engineered to control this constraint. Third,
the development of the site for two levels of underground parking will encounter the
Eocene-aged Santiago Formation which has been identified as having a high probability for
fossil content. While preservation is the prefened altemative for most cultural resources,
paleontologists require excavation to realize their potential. The project will be required
to retain a paleontologist to monitor the grading, recover and curate fossil materials, and
report findings. This completes the discussion of potential adverse impacts identified.
The environmental evaluation also includes a number of areas where no potential adverse
impacts could be identified. Due to the sites previous use as a heavy equipment storage
yard almost any proposal improves the biological environment, and the projects 30%
landscaping certainly acts in this fashion.
The physical and human environment of the site will obviously be altered, but outside of
the previous discussion, not in a manner that may be constmed as adverse. The previous
use was noted for noise, odor, and traffic hazards. The proposed use v^l not generate
these impacts due to the retail and office nature of the businesses projected to occupy the
stmcture. The three story stmcture has been setback from the intersection of state Street
and Laguna Drive so as to not obstmct any public scenic vista or create an aesthetically
offensive public view. The architecture of the stmcture is an intemationai style which is
compatible with the eclectic nature of the redevelopment area.
-6-
ANALYSIS OF VIABLE ALTERNATIVES TO THE PROPOSED PROJECT SUCH AS:
a) Phased development of the project,
b) altemate site designs,
c) altemate scale of development,
d) altemate uses for the site,
e) development at some future time rather than now,
f) altemate sites for the proposed, and
g) no project altemative.
a) Phased development of the project would not alter the impacts identified, as they are not
phase specific.
b) The impacts identified that could be altered by altemate site design have to do with
excavation for the imderground parking. However if surface parking was used less
landscaping would result. In fact off-site parking would have to be created. These
would not be viable prefened altematives.
c) An altemate scale of development would not alter the impacts identified as the impacts
are based upon any development.
d) Altemate uses for the site would not alter the impacts identified as they are not use
oriented.
c) Development at some future time rather than now does not alter impacts. This is an infill
lot with previous development that has left an adverse environmental condition that
development will conect.
f) There are altemate sites for the proposed project which would be compatible with the
uses, but not the stmcture. The project has been designed to maximize this particular
sites potential aesthetically as well as commercially.
g) The no project altemative condemns this site to remain a hazardous waste issue, an
unattractive nuisance, and a bUght on the City.
-7-
DETERMINATION (To Be Completed By The Planning Department)
On the basis of this initial evaluation:
I find the proposed project COULD NOT have a significant effect on the environment, and a
NEGATIVE DECLARATION will be prepared.
_X I find that although the proposed project could have a significant effect on the environment, there
will not be a significant effect in this case because the mitigation measures described on an
attached
sheet have been added to the project. A Conditional Negative
Declaration will be proposed.
I find the proposed project MAY have a significant effect on the environment, and an
ENVIRONMENTAL IMPACT REPORT is required.
7/2^ hn 3/u,j^jid^
'Date / Signature
Date Planning Director L/
-8-
LIST MITIGATING MEASURES (IF APPLICABLE)
1. Excavations over 5 feet in depth from existing grade whould be shored or laid back to inclinations of
1:1, in accordance with OSHA requirements. Shoring design parameters shall be provided prior to
constmction to the satisfaction of the Building Official.
2. The removal of and contamination remedial program for the hydrocarbon fuel contaminated soil shall
be performed in accordance with the requirements of the Coimty of San Diego Department of Health
Services and the San Diego Regional Water Quality Control Board. Documentation of the successful
completion of this program shall be provided prior to issuance of a grading or building pennit.
3. A. Qualified consulting paleontologist shall be retained prior to the issuance of any pennits to grade
or begin constmction of any part of the proposed project.
B. The consulting paleontologist shall attend at least one pregrading meeting to consult with the
grading and excavation contractors.
C. The consulting paleontologist shall be kept informed of the grading schedule and shall perform
periodic inspections of grading and constmction. When grading affects the Santiago Formation,
full-time monitoring may be necessary.
D. In the event that fossils are discovered, the consulting paleontologist shall be allowed to
temporarily halt, direct, or divert grading to allow recovery of fossil material in a timely marmer.
E. Any fossil materials collected from the site shall be cleaned, sorted, and cataloged and then
donated to an institution with a research interest in the materisl, such as the San Diego Natural
History Museum.
F. Within six weeks of the completion of grading for the project, the consulting paleontologist shall
prepare a report of findings, even if negative, and submit it to the City of Carl;sbad Planning
Department and the San Diego Natural History Museum.
APPLICANT CONCURRENCE WITH MITIGATING MEASURES
THIS IS TO CERTIFY THAT I HAVE REVIEWED THE ABOVE MITIGATING MEASURES
AND CONCUR WITH THE ADDITION OF THESE MEASURES TO THE PROJECT.
Dat& feijmature \
•9-
UIGHTON AND ASSOCIATES, INC
Geotechnical ond Environmental Engineering Consultants
PRELIMINARY GEOTECHNICAL INVESTIGATION,
PROPOSED BEVERLY CENTRE,
2530 STATE STREET,
CARLSBAD, CALIFORNIA
April 27, 1990
Project No. 8900136-01
Prepared For:
BEVERLY INVESTMENT GROUP
P.O. Box 1787
Carlsbad, California 92008
5421 AVENIDA ENCINAS, SUITE C, CARLSBAD, CALIFORNIA 92008 (619) 931-9953
FAX (619) 931-9326
UICHTON AND ASSOCIATES, INC
Geotechnical and Environmental Engineering Consultants
April 27, 1990
Project No. 8900136-01
To: Beverly Investment Group
P.O. Box 1787
Carlsbad, California 92008
Attention: Mrs. Beverly Southers:
Subject: Preliminary Geotechnical Investigation, Proposed Beverly Centre,
2530 State Street, Carlsbad, California
In accordance with your request and authorization, we have conducted a
prel iminary geotechnical investigation ofthe subject property. The accompanying
report presents a summary of our investigation and provides conclusions and
recommendations relative to the proposed site development.
If you have any questions regarding this report, please do not hesitate to
contact this office. We appreciate this opportunity to be of service.
Respectfully submitted,
LEIGHTON AND ASSOCIATES, INC.
Robert F. Riha
Senior Staff Geologist
Michael R. Stewart, CEG 1349 (Exp. 6/30/90)
Chief Geologist
Stan Helenschmidt, GE 2064 (Exp. 6/30/92)
Chief Engineer/Manager
RFR/MRS/SRH/bje
Distribution: (6) Addressee
5421 AVENIDA ENCINAS, SUITE C, CARLSBAD, CALIFORNIA 92008 (619) 931-9953
FAX (619) 931-9326
8900136-01
TABLE OF CONTENTS
Section Page
1.0 INTRODUCTION 1
1.1 Purpose and Scope 1
1.2 Site Location and Description 1
1.3 Proposed Development 2
2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING 3
3.0 SUMMARY OF GEOTECHNICAL CONDITIONS 4
3.1 Geologic Setting 4
3.2 Site-Specific Geology 4
3.2.1 Santiago Formation (Map Symbol - Ts) 4
3.2.2 Terrace Deposits (Map Symbol - Qt) 4
3.2.3 Undocumented Fills (Map Symbol - Afu) 5
3.3 Geologic Structure 5
3.4 Ground Water 5
4.0 FAULTING AND SEISMICITY 6
4.1 Faulting 6
4.2 Seismicity 6
4.2.1 Lurching and Shallow Ground Rupture 7
4.2.2 Liquefaction and Dynamic Settlement 7
4.2.3 Tsunamis and Seiches 7
5.0 CONCLUSIONS 8
6.0 RECOMMENDATIONS 9
6.1 Earthwork 9
6.1.1 Site Preparation 9
6.1.2 Excavations 9
6.1.3 Fill Placement and Compaction 9
6.1.4 Removal of Compressible Soils 10
6.1.5 Subdrainage 10
6.2 Temporary Excavation Slope Stability 10
6.2.1 Cut Slope Stability 10
LEIGHTON AND ASSOCIATES, INC.
8900136-01
TABLE OF CONTENTS (Cont'd.)
6.3 Surface Drainage and Erosion 11
6.4 Foundation and Slab Design Considerations 11
6.5 Lateral Earth Pressures and Resistance 12
6.6 Type of Cement for Construction 13
6.7 Corrosion Potential 13
6.8 Pavement Sections 13
6.9 Construction Observation and Foundation/Grading Plan Review 13
Appendices
Appendix A
Appendix B
Appendix C
Appendix D
References
Boring Logs
Laboratory Testing Procedures and Test Results
General Earthwork and Grading Specifications
Tables
Table 1 - Seismic Parameter for Active and Potentially Active Faults 14
Fiqures
Figure 1 - Site Location Map
Figure 2 - Geotechnical Map
15
16
n -
8900136-01
1.0 INTRODUCTION
1.1 Purpose and Scope
This report presents the results of our preliminary geotechnical
investigation at the site. The purpose of our investigation was to identify
and evaluate the existing geotechnical conditions present at the site and
to provide preliminary conclusions and geotechnical recommendations relative
to the proposed development. Please note that additional analysis may be
warranted when specific foundation design plans are developed. Our scope
of services included:
• Review of available pertinent, published and unpublished geotechnical
literature and maps (Appendix A).
• Aerial photographic analysis to assess the general geology of the site
and the possible presence of faulting and landsliding (Appendix A).
• Subsurface exploration consisting of the excavation, logging, and
sampling of three small-diameter borings. The logs of the borings are
presented in Appendix B. Approximate borehole locations are presented
on Figure 2.
• Laboratory testing of representative soil samples obtained from the
subsurface exploration program. Results of these tests are presented in
Appendix C and on the boring logs (Appendix B).
• Compilation and analysis of the geotechnical data obtained from our field
investigation and laboratory testing program.
• Preparation of this report presenting our findings, conclusions, and
geotechnical recommendations with respect to site grading and general
construction considerations.
1.2 Site Location and Description
The site of the proposed development encompasses approximately 0.44 acres
of predominantly vacant land previously occupied by Hawthorne Equipment
Rental Co. The rectangular-shaped site is bounded on the north by Laguna
Drive, on the west by State Street, on the east by vacant land, and on the
south by a developed lot with four wood-framed structures. The subject site
is located approximately 300 feet south of the Buena Vista Lagoon.
Prior to this investigation, hydrocarbon fuel contamination was detected by
Hekimian and Associates, Inc. (Hekimian 1989) during removal of five
underground fuel and waste oil storage tanks. The removal and contamination
remedial program was performed by Hekimian and Associates, Inc. under
contract to Hawthorne Rental. We understand that the contaminated soils
have been removed and/or are being properly treated in accordance with the
requirements of the County of San Diego Department of Health Services and
the San Diego Regional Water Control Board and, therefore, determination of
hydrocarbon presence was not within the scope of this investigation.
1 -
LEIGHTON AND ASSOCIATES, INC.
8900136-01
1.3 Proposed Development
As indicated on the site development plan, we understand that the subject
site will be developed as a three-story commercial building with two levels
of underground parking. We anticipate proposed grading will consist of
excavation for the subsurface parking and backfill of subsurface retaining
walls. In addition, we understand that the proposed structure will be
founded on conventional spread footings. Anticipated column loads were not
provided at the time of this study.
LEIGHTON AND ASSOCIATES, INC
8900136-01
2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING
Our subsurface exploration consisted of the excavation of three 8-inch diameter
hollow-stem borings to a maximum depth of 42 feet. The purpose of these
excavations was to help evaluate the physical characteristics of the onsite soils
pertinent to the proposed development.
The exploratory excavations were surface logged by a geologist from our firm.
Representative bulk and undisturbed (drive cylinder) samples were obtained for
laboratory testing. The approximate locations of the borings are shown on
Figure 2. Logs of the borings are presented in Appendix B. Subsequent to
logging and sampling, all borings were backfilled.
Laboratory testing was performed on representative samples to evaluate the
density and strength characteristics of the subsurface soils. A discussion of
the laboratory tests performed and a summary of the laboratory test results are
presented in Appendix C. In-situ moisture and density test results are provided
on the boring logs (Appendix B).
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LEIGHTON AND ASSOCIATES, INC
8900136-01
3.0 SUMMARY OF GEOTECHNICAL CONDITIONS
3.1 Geoloqic Settinq
The subject site is situated in the coastal section of the Peninsular Range
Province, a geomorphic province with a long and active geologic history
throughout southern California. Throughout the last 54 million years, the
area known as the "San Diego Embayment" has undergone several episodes of
marine inundation and subsequent marine regression, resulting in the
deposition of a thick sequence of marine and nonmarine sedimentary rocks on
the basement rock of the southern California batholith.
Gradual emergence of the region from the sea occurred in Pleistocene time,
and numerous wave-cut platforms, most of which were covered by relatively
thin marine and nonmarine terrace deposits, formed as the sea receded from
the land. Accelerated fluvial erosion during periods of heavy rainfall,
coupled with the lowering of the base sea level during Quaternary times,
resulted in the rolling hills, mesas, and deeply incised canyons which
characterize the landforms of the area.
3.2 Site-Specific Geology
Based on our subsurface exploration (Appendix B), aerial photographic
analysis, and review of pertinent geologic literature and maps (Appendix A),
the bedrock units underlying the site consist of the Eocene-aged Santiago
Formation and the Quaternary-aged terrace deposits. Surficial units noted
mantling these bedrock units include existing undocumented fill soils. The
approximate areal distribution of these units is depicted on the
Geotechnical Map (Figure 2). A brief description of the geologic units
(oldest to youngest) encountered on the site is presented below.
3.2.1 Santiago Formation (Map Symbol - Ts)
The Eocene-aged Santiago Formation as observed on the site consists
of very dense, clean to silty, locally slightly clayey, fine- to
coarse-grained sandstone.
3.2.2 Terrace Deposits (Map Svmbol - Ot)
The entire site is mantled by Quaternary-aged Marine Terrace
Deposits. This sedimentary unit is predominantly comprised of red-
brown, dense to very dense, fine to medium sand with scattered to
locally abundant gravel and cobbles. The upper 1 to 2 feet of these
terrace deposits are highly weathered and disturbed in areas.
LEIGHTON AND ASSOCIATES, INC.
8900136-01
3.2.3 Undocumented Fills (Map Symbol - Afu)
Undocumented fills are present on the site as fills associated with
construction of the existing parking lot and backfill of existing
retaining walls and the fuel tank removal excavations. These soils
are considered potentially compressible and will require removal and
recompaction. It is possible that fill soils placed on site after
recent removal of the fuel tanks may have been documented by others.
However, no documentation for these fill soils has been reviewed by
this firm. As a result, these soils were considered to be
uncompacted.
3.3 Geologic Structure
The terrace deposits in the vicinity are generally massive with no well-
defined bedding or structure. The contact between the terrace deposits and
underlying Santiago Formation undulates slightly, but is generally
horizontal.
Based on our review of geologic literature, the geologic structure within
the Santiago Formation is generally controlled by a gentle, westerly to
northwesterly dip component.
3.4 Ground Water
As encountered in our exploratory borings, the depth to the ground water
table varied from 21 to 23 feet below existing grade. The depths to ground
water are summarized below:
Boring Approximate Depth to Water Table (feet)
B-1
B-2
B-3
21
23
23
Ground water levels are affected by seasonal fluctuations in rainfall and
irrigation practices in the area of the site. Therefore, some minor
deviation from the above depths to ground water may be anticipated at future
dates.
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LEIGHTON AND ASSOCIATES, INC
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4.0 FAULTING AND SEISMICITY
4.1 Faulting
Our review of available geologic literature (Appendix A>, indicates that
there are no known major or active faults on or in the immediate vicinity
of the site. The nearest active regional faults are the Coronado Banks
fault zone, located offshore approximately 21 miles southwest of the site
and the Elsinore fault zone, located approximately 23 miles northeast of
the site.
The Rose Canyon fault is approximately 4.5 miles west of the site. Since
definitive geologic evidence for active faulting on the Rose Canyon fault
is not known, the Rose Canyon fault in the San Diego area has been
classified as potentially active based on the criteria set forth by the
California Division of Mines and Geology (CDMG 1985). However, some
geologists consider the Rose Canyon fault zone to be active. Recent studies
in the downtown area of San Diego and seismic events during June 1985 in the
vicinity of the southern, off-shore extension of the Rose Canyon fault
(approximately 4.5 miles southwest of the site) may indicate activity on
that section of the Rose Canyon fault. However, conclusive data to
reclassify the fault as active, based on California Division of Mines and
Geology (CDMG) guidelines (CDMG 1985), have not been developed.
4.2 Seismicity
The subject site can be considered to lie within a seismically active
region, as can all of southern California. Table 1 (rear of text) indicates
potential seismic events that could be produced by maximum probable
earthquakes. A maximum probable earthquake is the maximum expectable
earthquake produced from a causative fault during a lOO-year interval.
Site-specific seismic parameters included in Table 1 are the distance to
the causative faults, Richter earthquake magnitudes, expected
peak/repeatable high ground accelerations (RHGA), and estimated period and
duration of ground shaking.
As indicated in Table 1, the Elsinore fault is considered to have the most
significant effect at the site from a design standpoint. A maximum probable
earthquake of Richter Magnitude 7.3 on the fault could produce a peak
repeatable horizontal bedrock acceleration of approximately 0.24g. The
effect of seismic shaking may be mitigated by adhering to the current
Uniform Building Code or state-of-the-art seismic design parameters of the
Structural Engineers Association of California.
Secondary effects associated with severe ground shaking following a
relatively large earthquake which may affect the site include ground
lurching and shallow ground rupture, soil liquefaction and dynamic
settlement, seiches and tsunamis. These secondary effects of seismic
shaking are discussed below.
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LEIGHTON AND ASSOCIATES, INC.
8900136-01
4.2.1 Lurching and Shallow Ground Rupture
Soil lurching refers to the rolling motion on the surface by the
passage of seismic surface waves. Effects of this nature are likely
to be significant where the thickness of soft sediments vary
appreciably under structure. Damage to the proposed development
should not be significant if the potentially compressible soils
present on the site are properly densified in accordance with the
recommendations of this report (Section 6.0).
Breaking of the ground because of active faulting is not likely to
occur on site due to the absence of active faults. Cracking due to
shaking from distant seismic events is not considered a significant
hazard, although it is a possibility at any site.
4.2.2 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 silty
clays and clays is not adversely affected by vibratory motion.
Liquefaction is typified by a total loss of shear strength in the
affected soil layer, thereby causing the soil to flow as a liquid.
This effect may be manifested by excessive settlements and sand boils
at the ground surface.
The onsite materials below the ground water table are not considered
liquefiable due to their high density characteristics.
4.2.3 Tsunamis and Seiches
Tsunamis and seiches are seismically induced waves created in oceans
and closed bodies of water, respectively. 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.
LEIGHTON AND ASSOCIATES, INC.
8900136-01
5.0 CONCLUSIONS
Based on the results of our preliminary geotechnical investigation of the site,
it is our opinion that the proposed development is feasible from a geotechnical
standpoint provided the following conclusions and recommendations are
incorporated into the project plans and specifications.
The following is a summary of the geotechnical factors which may affect
development of the site.
• Active faults are not known to exist on or in the immediate vicinity of the
site. However, some minor inactive faulting or subfaults may be encountered
during grading. If encountered, these faults should be evaluated at that
time.
• The maximum anticipated repeatable bedrock acceleration on the site due to a
probable earthquake on the Elsinore fault zone of Richter Magnitude 7.3 is
estimated to be approximately 0.24g.
• Based on subsurface exploration of the formational materials and surficial
soils present on the site, we anticipate that these materials should be
generally rippable with conventional heavy-duty earthwork equipment.
• Based on our field observations, subsurface exploration and laboratory
testing, highly weathered and disturbed portions of the terrace deposits (1
to 2 feet), and undocumented fill soils may be potentially compressible.
These soils are not considered suitable for support of structural loads and/or
additional fill soils in their present condition. Remedial grading measures
such as removal and recompaction in the area proposed for development will be
necessary to mitigate this condition (Section 6.1.4).
• Based on visual classification, materials derived from the Santiago Formation
and Terrace Deposits on the site generally possess a low expansion potential.
• The existing onsite soils appear to be suitable material for fill construction
provided they are relatively free of organic material, debris, and rock
fragments larger that 6 inches in dimension.
• Ground water was encountered in the borings drilled on site and may be a
constraint to the development of the site. Recommendations for the control
•^ana/or dewatering of the site can be provided by this office prior to
construction.
• Based on the site development plan, excavations on the order of 25 feet deep
are proposed adjacent to existing property boundaries. Vertical excavations
in the sandy terrace materials may not be stable. We recommend that
excavations over 5 feet deep be laid back at inclinations of 1:1 (horizontal
to vertical), or be supported byshoring.
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LEIGHTON AND ASSOCIATES, INC
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6.0 RECOMMENDATIONS
6.1 Earthwork
We anticipate that earthwork at the site will consist of site preparation,
excavation, and backfill. We recommend that earthwork on the site be
6.1.1 Site Preparation
Prior to grading, all areas to receive structural fill or engineered
structures should be cleared of surface and subsurface obstructions,
including any existing debris 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
obstructions which extend below finish 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 conditions, and
recompacted to at least 90 percent relative compaction (based on ASTM
Test Method 01557-78).
6.1.2 Excavations
Excavations of the onsite materials may generally be accomplished
with conventional heavy-duty earthwork equipment. Due to the high
density characteristics of the onsite Terrace Deposits, temporary
excavations at street level such as utility trenches with vertical
sides in this unit should remain stable for the period required to
construct the utility, provided they are free of adverse geologic
conditions. However, excavations over 5-feet deep, in accordance
with OSHA requirements, should be shored or laid back to 1:1
(horizontal to vertical) if workers are to enter such excavations.
At finished grade at basement level, excavations over 3 feet in depth
should be shored or laid back to inclinations of 1:1 (horizontal to
vertical) due to potential hydrostatic pressure.
6.1.3 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 dimension. All fill soils should be brought
to near-optimum moisture conditions and compacted in uniform lifts
to at least 90 percent relative compaction based on laboratory
standard ASTM Test Method 01557-78. 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.
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LEIGHTON AND ASSOCIATES, INC
8900136-01
Please note that the Terrace Deposits typically possess a moisture
content below optimum and may require moisture conditioning prior to
use as compacted fill. Fills placed on slopes steeper than 5:1
(horizontal to vertical) should be keyed and benched into competent
formational soils as indicated in the General Earthwork and Grading
Specifications presented in Appendix D.
Placement and compaction of fill should be performed in general
accordance with the current City of Carlsbad grading ordinances,
sound construction practice, and the General Earthwork and Grading
Specifications presented in Appendix D.
6.1.4 Removal of Compressible Soils
Undocumented fill soils are located in several areas of the site.
These soils and highly weathered or disturbed portions of the terrace
deposits should be removed to firm formational materials in the areas
of proposed grading or support of foundations. Based on our
knowledge of the site, undocumented fill soils may be up to ±20 feet
in thickness. Disturbed portions of the terrace deposits are
anticipated to be 1 to 2 feet in thickness. Localized deeper
removals as determined during grading may be necessary. The actual
depths and extent of required removals should be evaluated by the
geotechnical consultant during grading. After removals, the base of
the resulting excavations should then be scarified to a depth of at
least 6 inches, moisture-conditioned to near-optimum moisture
content, and recompacted to at least 90 percent of the maximum dry
density as determined in accordance with ASTM Test Method 01557-78.
6.1.5 Subdrainage
Based on the proposed development plan, portions of the proposed
structure will be below the existing water table. Basement walls
should be water-proofed per the recommendations of the civil
engineer. Walls should be provided with an appropriate backdrain as
detailed in Appendix D. Wall backdrains should be directed to a
sump/pump system below the subgrade elevation at the lowermost floor
level.
6.2 Temporary Excavation Slope Stability
6.2.1 Cut Slope Stability
Based on our analysis of the geotechnical conditions encountered
during our investigation, it is our opinion that excavations steeper
that 1:1 (horizontal to vertical) into the terrace materials and
Santiago Formation may not be stable. We recommend that shoring be
provided for all excavations steeper than 1:1 (horizontal to
vertical) exceeding 5 feet in depth. Shoring design parameters may
be provided by this office prior to construction.
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LEIGHTON AND ASSOCIATES, INC
8900136-01
6.3 Surface Drainage and Erosion
Surface drainage should be controlled at all times. The proposed structure
should have appropriate drainage systems to collect roof runoff. Positive
surface drainage should be provided to direct surface water away from the
structure toward the street or suitable drainage facilities. Positive
drainage may be accomplished by providing a minimum 2 percent gradient from
the structure. Planters should not be designed below grade adjacent to
structure unless provisions for drainage such as catch basins and pipe
drains are made. In general, ponding of water should be avoided adjacent
to the structure.
Protective measures to mitigate excessive site erosion during construction
should also be implemented in accordance with the latest City of Carlsbad
grading ordinances.
6.4 Foundation and Slab Design Considerations
Foundations and slabs should be designed in accordance with structural
considerations and the following recommendations. These recommendations
assume that the soils encountered within 4 feet of pad grade have a very low
potential for expansion.
As noted above, we understand that the proposed structure will consisted of
a three-story commercial building with two levels of underground parking
and will be founded on conventional continuous or isolated spread footings.
Footings bearing in firm, formational soils should extend a minimum of
24 inches below finished grade. At this depth, footings founded in firm,
formational soils with a minimum width of 3 feet may be designed for an
allowable bearing capacity of 4,500 psf. Allowable bearing capacity may be
increased by one-third for loads of short duration, including wind or
seismic forces. We recommend that both types of footings be reinforced with
a minimum of four No. 4 rebars, two top and two bottom.
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LEIGHTON AND ASSOCIATES, INC
8900136-01
Floor slabs (for very low expansive soils) should be at least 4 inches in
thickness and be provided with a minimum reinforcement of 6x6-10/10 wire
mesh. Care should be taken by the contractor to insure that the wire mesh
is placed at slab midheight. Slabs should be underlain by a 2-inch layer
of clean sand over a 6-mil Visqueen moisture barrier. In order to help
mitigate perforation, we recommend that a 2-inch layer of clean sand be
placed beneath the Visqueen.
The potential for slab cracking may be reduced by careful control of
water/cement ratios. The contractor should take appropriate curing
precautions during the pouring of concrete in hot weather to minimize
cracking of slabs. We recommend that a slipsheet be utilized if grouted
tile, marble tile, or other crack-sensitive floor covering is planned
directly on concrete slabs. All slabs should be designed in accordance with
structural considerations.
6.5 Lateral Earth Pressures and Resistance
Embedded structural walls should be designed for lateral earth pressures
exerted on them. The magnitude of these pressures depends on the amount of
deformation that the walls can yield under load. If walls can yield enough
to mobilize the full shear strength of the soil, they can be designed for
"active" pressure. If walls 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
structure 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
nonexpansive soils is provided below. Based on our investigation, the
sandier soils of the Santiago Formation and Terrace Deposits may provide
nonexpansive backfill material. If selective grading or stockpiling of
these soils is not feasible, walls should be backfilled with suitable
nonexpansive import soils approved by the geotechnical consultant.
Equivalent Fluid Weight (pcf)
Condition Level 2:1 Slope
Active 35 50
At-Rest 50
Passive 350
All retaining wall structures should be provided with appropriate drainage,
typical drainage design as described in Appendix D.
Wall backfill should be compacted by mechanical methods to at least
90 percent relative compaction (based on ASTM Test Method D1557-78). Should
structures be planned adjacent to the top of retaining walls, the
geotechnical consultant should be advised so further recommendations may be
provided.
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LEIGHTON AND ASSOCIATES, INC
8900136-01
Wall footings should be designed in accordance with the foundation design
recommendations (Section 6.4) and reinforced in accordance with structural
considerations.
Soil resistance developed against lateral structural movement can be
obtained from the passive pressure value provided above. Further, for
sliding resistance, a friction coefficient of 0.35 ma^ 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 that the passive portion does not exceed two-thirds of
the total resistance.
6.6 Type of Cement for Construction
Concrete in direct contact with soil or water that contains a high
concentration of soluble sulfates can be subject to chemical deterioration
known as "sulfate attack." Based on samples collected during our
investigation, the subsurface soils have a low potential for sulfate attack.
6.7 Corrosion Potential
Based on laboratory test results for pH and minimum resistivity (Appendix
C), the site soils above the ground water table have a "mild" potential for
corrosion. Because of the brackish ground water, structures below the
ground water table should be designed for high potential for corrosion.
6.8 Pavement Sections
Design of pavement sections was not included within the scope of this
report. Pavement sections will depend largely on the subgrade soil
conditions after grading. Pavement sections in accordance with City of
Carlsbad criteria can be provided upon completion of rough grading based on
laboratory R-value testing of subgrade soils.
6.9 Construction Observation and Foundation/Grading Plan Review
The recommendations provided in this report are based on preliminary design
information and subsurface conditions disclosed by widely spaced borings.
The interpolated subsurface conditions should be checked in the field during
construction. Construction observation of all onsite excavations and field
density testing of all compacted fill should be performed by representatives
of this office so that construction is in accordance with the
recommendations of this report. We recommend that excavations be
geologically mapped by the geotechnical consultant during grading for the
presence of potentially adverse geologic conditions.
Project grading foundation plans should be geotechnically reviewed by
Leighton and Associates to see that the recommendations provided in this
report are incorporated in project plans prior to site development.
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LEIGHTON AND ASSOCIATES, INC
8900020-01
TABLE 1
SEISMIC PARAMETERS FOR ACTIVE AND POTENTIALLY ACTIVE FAULTS
Beverly Centre
MAXIMUM PROBABLE 1
(Functional Basis
EARTHQUAKE
larthcuake)
Potential
Causative
Fault
Distance
From Fault
To Site
(Miles)
Richter
Magnitude
Peak Bedrock/
Repeatable
Horizontal
Ground Acceleration**
(Gravity)
Predominant
Period at
Site in
Seconds
Duration of
Strong
Shaking at
Site in
Seconds
Coronado Banks
(offshore)
21 6.0 0.10 0.26 6
Elsinore 23 7.3 0.24 0.35 25
La Nacion* 31.5 N.A. — —
Newport-
Inglewood 19.5 6.5 0.16 (.10) 0.30 14
Rose Canyon*
(offshore)
4.5 6.2 0.41 (.27) 0.28 18
San Andreas 65 8.3 0.09 0.62 5
San Jacinto 47.5 7.3 0.11 0.45 12
San Clemente 54.5 7.0 0.05 0.44 7
* This fault is considered "potentially active," based on our current knowledge of the geologic
conditions of the San Diego County area.
** For design purposes, the repeatable horizontal ground acceleration may be taken as 65 percent
of the peak acceleration for the site within approximately 20 miles of the epicenter (after
Ploessel and Slosson, 1974).
BASE MAP : Aerial Foto-Map Book Pg. 7D
0
scale
2000 4000
feet
I Project No. 8900136-01
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LEIGHTON AND ASSOCIATES
SITE LOCATION MAP
BEVERLY CENTRE
CARLSBAD, CALFORNIA
FIGURE 1
page 16
APPENDIX A
LEIGHTON AND ASSOCIATES, INC
8900136-01
APPENDIX A
REFERENCES
Albee, A.L., and Smith, J.L., 1966, Earthquake Characteristics and Fault Activity
Southern California in Lung, R., and Proctor, R., Eds., Engineering
Geology in Southern California, Association of Engineering Geologists,
Special Publication, dated October 1966.
Allen, C.R., Amand, P., Richter, C.F., and Nordquist, J.M., 1965, Relationship
Between Seismicity and Geologic Structure in Southern California,
Seismological Society of America Bulletin, Vol. 55, No. 4,
pp. 753-797.
Anderson, J.G., Rockwell, T., and Agnew, D.C, 1987, A Study of the Seismic
Hazard in San Diego: Preliminary Draft Submitted to Earthquake
Spectra, dated November 17, 1987.
ARK Architecture and Planning, 1989, Major Development Package, Beverly Centre,
Carlsbad, California, dated November 23, 1989.
Association of Engineering Geologists, 1973, Geology and Earthquake Hazards,
Planners Guide to the Seismic Safety Element: Southern California
Section A.E.G., Spec. Pub., July 1973, 44p.
Bell, J.M., 1966, Dimensionless Parameters for Homogeneous Earth Slopes, Journal,
Soil Mechanics and Foundations Division, American Society of Civil
Engineers, No. SMS, dated September 1966.
Bolt, B.A., 1973, Duration of Strong Ground Motion, Proc. Fifth World Conference
on Earthquake Engineering, Rome, Paper No. 292, pp. 1304-1313, dated
June 1973.
Bonilla, M.J., 1970, Surface Faulting and Related Effects, in Wiegel, R., Ed.,
Earthquake Engineering, New Jersey, Prentice-Hall, Inc., pp. 47-74.
Greensfelder, R.W., 1974, Maximum Credible Rock Acceleration From Earthquakes
in Cal ifornia, Cal ifornia Division of Mines and Geology, Map Sheet 23.
Hannan, D.L., 1975, Faulting in the Oceanside, Carlsbad, and Vista Areas,
Northern San Diego County, California in Ross, A. and Dowlen, R.J.,
eds.. Studies on the Geology of Camp Pendleton and Western San Diego
County, California, San Diego Association of Geologists Field Trip
Guidebook, pp. 56-60.
Hart, 1985, Fault-Rupture Hazard Zones In California, 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.
Hekimian and Associates, Inc., 1990, Site Assessment Report and Remedial Action
Plan for Hawthorne Rent-It Service, 2530 State Street, Carlsbad,
California, dated January 15, 1990.
A-l
8900136-01
REFERENCES (Continued)
International Conference of Building Officials, 1985, Uniform Building Code.
Jennings, C.W., 1975, Fault Map of California, Scale 1:750,000, California
Division of Mines and Geology, Geologic Map No. 1.
Lamar, D.L., Merifield, P.M., and Proctor, R.J., 1973, Earthquake Recurrence
Intervals on Major Faults in Southern California, in Moran, D.E.,
Slosson, J.E., Stone, R.O., and Yelverton, C.A., Eds., 1973, Geology,
Seismicity, and Environmental Impact, Association of Engineering
Geologists, Special Publication.
Leighton and Associates, Inc., Unpublished In-House Geotechnical Data.
Ploessel, M.R., and Slosson, J.E., 1974, Repeatable High Ground Accelerations
From Earthquakes -- Important Design Criteria, California Geology,
V. 27, No. 9.
Power, M.S., Dawson, A.W., et. al., 1982, Evaluation of Liquefaction
Susceptibility in the San Diego, California Urban Area, Final
Technical Report, Volumes I and II, Sponsored by the U.S. Geological
Survey.
Real, C.R., Toppazada, T.R., and Parke, D.L., 1978, Earthquake Epicenter Map of
California, California Division of Mines and Geology, Map Sheet 39.
Schnabel, R., and Seed, H.B., 1974, Accelerations in Rock for Earthquakes in
the Western United States, Bulletin of the Seismological Society of
America, V. 63, No. 2, pp. 501-516.
Seed, H.B., 1979, Soil Liquefaction and Cyclic Mobility Evaluation for Level
Ground During Earthquakes, ASCE GT2, p. 201, February 1979.
Seed, H.B., Idriss, I.M., and Arango, Ignacio, 1983, Evaluation of Liquefaction
Potential Using Field Performance Data, ASCE JGE, Vol. 109, No. 3,
p. 458, dated March 1983.
Seed, H.B., and Idriss, I.M., and Kiefer, F.W., 1969, Characteristics of Rock
Motions During Earthquakes, Journal of Soil Mechanics and Foundations
Division, ASCE, V. 95, No. SMS, Proc. Paper 6783, pp. 1199-1218, dated
September 1969.
A-2
8900136-01
REFERENCES (Continued)
Weber, F. Harold, Jr., 1982, Recent Slope Failures, Ancient Landslides and
Related Geology of the North-Central Coastal Area, San Diego County,
California, California Division of Mines and Geology, Open File Report
82-12, LA.
AERIAL PHOTOGRAPHS
Date Source Flight Photo No.
5/02/53 San Diego County AXN-14M 20, 21
A-3
APPENDIX B
LEIGHTON AND ASSOCIATES, INC
April 11, 1990 Date
Project Beverly Centre
GEOTECHNICAL BORING LOG
Drill Hole No. B-1
Drilling Co.
Hole Diameter 8 in.
F&C Drilling
Project No.
Type of Rig
Sheet 1 of 2
8900136-01
Hollow Stem Auger
Drive Weight 140 pounds Drop 30 11:,.
Elevation Top of Hole ±41' Ref. or Datum See Geotechnical Map
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I 4 • 52/6" 113.5 17.8 SP
I 5 •50/4" 123.0 13.1
I 6 •50/4" 121.2 12.5
ASPHALTIC CONCRETE:
@ 0 - 0.5' Asphaltic concrete
CONCRETE:
@ 0.5 to 1.5' Concrete
TERRACE DEPOSITS:
Red-brown, slightly moist, dense to very
dense, medium to fine, silty sand (slightly
silty)
I
i
t
t
0 12' Brown to tan, slightly moist to
moist; very dense, medium to fine,
silty sand; slightly silty with
scattered gravels; slightly micaceous
@ 16' Tan-gray, wet to saturated, very
dense, fine sand; highly micaceous
with rounded gravels
SANTIAGO FORMATION:
Light tan, saturated, very dense, coarse to
fine, silty sand with some subrounded gravels
j
Leighton and Associates, Inc.
Date April IK 1990
GEOTECHNICAL BORING LOG
Drill Hole No. B-1 Sheet 2 of 2
Project Beverly Centre
Drilling Co.
Hole Diameter
F&C Drilling
Project No.
Type of Rig
8900136-01
8 in. Drive Weight 140 pounds
Hollow Stem Auger
Drop 30 in
Elevation Top of Hole ±41' Ref. or Datum See Geotechnical Map
4-> o. <u
o.
•r" x: cn
Q. o
&-
CO
CO
O)
"O
3 •M 3 r—
h- Q.
E ea
00
o o
Ll.
Q.
>> 4J •r"
<A ^
C 4-
<u o
O Q.
$- •<
3 +J
+J C
(/) <U
•1-o c s: o o
tA
oo
GEOTECHNICAL DESCRIPTION
Logged by
Sampled by
JF
JF
30
35—
40-
0 30' Same as above with green, slightly
clayey interiayers
I 7| 50/4" 125.1 12.1
SKIP
9 150/5" 122.4 13.5
45-
50-
55-
60-
Total Depth = 43 Feet
Brackish Ground Water Encountered at 21 Feet
Backfilled 4/11/90
Leighton and Associates, Inc.
April 11, 1990 Date
Project Beverly Centre
GEOTECHNICAL BORING LOG
Drill Hole No. B-2
Drilling Co. F&C Drilling
Project No.
Type of Rig
Hole Diameter 8 in. Drive Weight 140 pounds
Sheet 1 of 2
8900136-01
Hollow Stem Auger
Drop 30 in.
Elevation Top of Hole ±41' Ref. or Datum See Geotechnical Map
JZ
Q.
O.
JZ O)
Q. O ea _J
to
(U "XD <u
3 r—
I— CL E ra oo
tA s c <+-<u o o a.
>>'
L.
O
i. H
3 4->
4J C
tA OJ
•I- +J
o c
S O
O
tA
ea
o
oo
oo
o,
oo
GEOTECHNICAL DESCRIPTION
Logged by
Sampled by
JF
JF
5-
10-
15-
''.0.
O •.
20-
25-
30
SM
® I 1 ^67 123.1 7.7
SM/SP
I 2^39 98.4 3.6
NR
SW-SM
N.R.
5|50/3^.. 127.8 11.0
ASPHALTIC CONCRETE:
0 0- 0.5' Asphaltic concrete
TERRACE DEPOSITS:
Red-brown, slightly moist, dense, medium to
fine, silty sand; slightly silty
11.5' Tan-gray, damp to slightly moist,
medium dense, fine, silty sand;
slightly silty, sTightTy micaceous,
orange, oxidized inter!ayers
@ 17' Abundant rounded coarse gravels in
cuttings
SANTIAGO FORMATION:
Light tan, wet to saturated, very dense, well
graded, silty sand with slightly silty
horizons
Leighton and Associates, Inc.
Date April 11, 1990
GEOTECHNICAL BORING LOG
Drill Hole No. B-2 Sheet 2 of 2
Project Beverly Centre
Drilling Co.
Hole Diameter
F&C Drilling
Project No.
Type of Rig
8900136-01
8 in. Drive Weight 140 pounds
Hollow Stem Auger
Drop 30 in
Elevation Top of Hole ±41' Ref. or Datum See Geotechnical Map
Q.
o
JZ cn Q. O ea _J
C3
to <u T3 3 •4->
<
jQ QJ
3 I—
}- CL. E ea oo
CQ QJ
OL.
tA <
C 4-
QJ U
Q Q.
>>^
Q
QJ
L. •
3 4->
•*-> C to Q)
•r- +J o c s: o o
tA
r— ^
CO
GEOTECHNICAL DESCRIPTION
Logged by
Sampled by
JF
JF
30
35-
40-
@ 30' Same as above
I 6 •50/ 4k" 124.8 11.5
I 7 150/5" 123.5 12.9
8 150/4" 122.5 11.7
45-
50-
55-
60.
Total Depth = 43 Feet
Ground Water Encountered at ±23 Feet
Backfilled 4/11/90
Leighton and Associates, Inc.
April 11, 1990 Oate
Project Beverly Centre
GEOTECHNICAL BORING LOG
Drill Hole No.
Drilling Co. F & C Drilling
Hole Diameter 8 in.
B-3 Sheet 1 of 2
Project No. 8900136-01
Type of Rig Hollow Stem Auger
Drive Weight 140 pounds Drop 30 in.
Elevation Top of Hole ±41' Ref. or Datum See Geotechnical Map
JC '
a.
QJ
Q,
JZ cn a. o ea ..J s.
to
QJ •a
3 Ji QJ
3 f— I— Q. E <a oo
o o u.
c; a.
to
c «*-
QJ U
O Q.
o
QJ
S- •«
3 +J
+J C
to QJ
•r- +J
O C
s o
GEOTECHNICAL DESCRIPTION
Logged by
Sampled by
JF
JF
• . a a
10-
15-
20-
25-
30
®
I 1 • 51 113.1 6.0
I 77 112.0 5.4
3 150/4" 119.8 13.4
118.8 12.5
5 150/^ 122.5 11.2
SM
SP
SM
ASPHALTIC CONCRETE:
0 0- 0.5' Asphaltic concrete
TERRACE DEPOSITS:
Red-brown, damp to slightly moist, medium
dense, medium to fine, slightly silty sand
0 5' Clayey interiayer in cuttings with
some rounded gravels
0 7' Red-brown, damp to slightly moist,
medium dense, medium to fine sand;
very slightly silty
0 12' As above; weakly micaceous with
petrochemical odor
.SANTIAGO FORMATION:
Tan, moist to wet, dense to very dense, well
graded, silty sand; some slightly clayey
horizons
Leighton and Associates, Inc.
April 11, 1990 Date
Project Beverly Centre
GEOTECHNICAL BORING LOG
Drill Hole No. B-3 Sheet 2 of 2
Project No. 8900136-01
F&C Drilling Drilling Co.
Hole Diameter
Elevation Top of Hole ±41'
8 in. Drive Weight _
Ref. or Datum
140 pounds
See Geotechnical Map
Type of Rig Hollow Stem Auger
Drop 30 in
Q.
x: cn Q. o ea _J u
to
QJ
•o
3 QJ
3 I—
i— CL E ea oo
to -—• c u-
QJ U
o a.
Q
tA
G«-J
I— ^
oo
GEOTECHNICAL DESCRIPTION
Logged by
Sampled by
JF
JF
30 SM 0 30' Same as above
I 6150/ 115.2 11.6
35-
40-
45-
50-
55-
60-
Total Depth = 33 Feet
Ground Water Encountered at ±23 Feet
Backfilled 4/11/90
Leighton and Associates, inc.
APPENDIX C
LEIGHTON AND ASSOCIATES, INC
8900136-01
APPENDIX C
LABORATORY TESTING PROCEDURES AND TEST RESULTS
Moisture and Density 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.
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 0.05 inches per minute. After a
travel of 0.300 inches of the direct shear machine, the motor was stopped and
the sample was allowed to "relax" for approximately 15 minutes. The "relaxed"
and "peak" shear values were recorded. It is anticipated that, in a majority
of samples tested, the 15 minutes relaxing of the sample is sufficient to allow
dissipation of pore pressures set up in the samples due to application of
shearing force. The relaxed values are therefore judged to be a good estimation
of effective strength parameters. The test results were plotted on the "Direct
Shear Summary".
For residual direct shear test, the samples were sheared, as described in the
preceding paragraph, with the rate of shearing of 0.001 inches per minute. The
upper portion of the specimen was pulled back to the original position and the
shearing process was repeated until no further decrease in shear strength was
observed with continued shearing (at least three times resheared). There are
two methods to obtain the shear values: (a) the shearing process was repeated
for each normal load applied and the shear value for each normal load was
recorded. One or more than one specimen can be used in this method; (b) only
one specimen was needed, and a very high normal load (approximately 9000 psf)
was applied from the beginning of the shearing process. After the equilibrium
state was reached (after "relaxed"), the shear value for that normal load was
recorded. The normal loads were then reduced gradually without shearing the
sample (the motor was stopped). The shear values were recorded for different
normal loads after they were reduced and the sample was "relaxed".
Soluble Sulfates: The soluble sulfate contents of selected samples were
determined by the California Materials Method No. 417.
C-1
3000-
2500
i
2000
€0
5
1000
600
8di DMcrtoOon: Brown, Tan.Fine Sand
Type of Sainple: •Rewx
Rela
3<ded to 1 1
n
Type of Sainple: •Rewx
Rela live Compaction
1
n
nriUndtoturted
Uwdina Rate: .005 kUiHrv
H
•
-i
1 1
1 1
1 1 1 1 1
1 j 1 1 1 1
1 1 1 1 •
1 j 1 1 j V 1 1 1 1 1 1 1
1 1 ^y
j 1
1 rf) y^ 1 t
kf 1 y 1 \ A 1
1
T
• ^y 1 j 1
1 1
1 1 1 1
600
Sample Location Symbol
B-1; #3 0 12'
1000 1500 2000
NORMAL STRESS, paf
Avaraga
Moisture ContaiHa
Befora Aftar Friction Angia
33'
2500 SOOO
Cohaaion Ramarlis
188
DIRECT SHEAR TEST RESULTS
Projaet No. 8900136-01
Projaet Naaia Beverly Center
Data 4/19/90 HO. ^ ma 3016 1088
3000-
2500
CO
5
2000
1600
1000
600
Soi Daacrip<
TVpa of Saxr
•M- Tan, Silty Sand
1
n
Soi Daacrip<
TVpa of Saxr ipla: nRamokiad to 1 1
n Ralativa Compactkx
1
n
rxlUndtotut>ad
Loadina Rata: 005
• 1 1
1 1 /
1 1 /
1 1 \ /
1 1 T /
1 j y
i A 1 1 / 1
1 1 /
j 1 /
1 } / 1 1 j / 1 1 ! y
1 1 / 1 1 /
1 1/
1 \
T
\ / 1
1 / 1 y 1
/ 1 1
/ 1
• / 1 j / 1
1
/ 1 1 1 Jl
600
Sample Location Symbol
B-3; #4 0.22'
1000 1500 2000 2500
NORMAL STRESS, paf
Avaraga
Moiatura Contanta
Befora Aftar Friction Angia
44° 138
SOOO
Cohaaion Remarks
DIRECT SHEAR TEST RESULTS
Proiact Mo. 8900136-01
Projaet Maaia Beverly Center
Data JZgg/9Q, Figure No. m 3015 1088
pH AND MINIMUM RESISTIVITY TEST RESULTS
SAMPLE NUMBER pH MINIMUM RESISTIVITY
(ohm-cm)
B-1; #2 0 13' 7.8 20,000
Project No:
8900136-01
LEIGHTON AND ASSOCIATES
BEVERLY CENTER
SOLUBLE SULFATES
SAMPLE *
B-1; #2
B-3; #5
DILUTION
3:1
3:1
READING PPM
3 X 50 = 150
3 X 50 = 150
% SULFATES
.0150
.0150
POTENTIAL DEGREE
OF SULFATE ATTACK
low
low
Ptoject No.
8900136-01
BEVERLY CENTER
Rjure^^C^
APPENDIX D
LEIGHTON AND ASSOCIATES, INC
8900136-01
APPENDIX D
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
1.0 General Intent
These specifications are presented as general procedures and recommendations
for grading and earthwork to be utilized in conjunction with the approved
grading plans. These general earthwork and grading specifications are a
part of the recommendations contained in the geotechnical report and shall
be superseded by the recommendations in the geotechnical report in the case
of conflict. Evaluations performed by the consultant during the course of
grading may result in new recommendations which could supersede these
specifications or the recommendations of the geotechnical report. It shall
be the responsibility of the contractor to read and understand these
specifications as well as the geotechnical report and approved grading
plans.
2.0 Earthwork Observation and Testing
Prior to the commencement of grading, a qualified geotechnical consultant
should be employed for the purpose of observing earthwork procedures and
testing the fills for conformance with the recommendations of the
geotechnical report and these specifications. It shall be the
responsibility of the contractor to assist the consultant and keep him
apprised of work schedules and changes, at least 24 hours in advance, so
that he may schedule his personnel accordingly. No grading operations
should be performed without the knowledge of the geotechnical consultant.
The contractor shall not assume that the geotechnical consultant is aware
of all grading operations.
It shall be the sole responsibility of the contractor to provide adequate
equipment and methods to accomplish the work in accordance with applicable
grading codes and agency ordinances, recommendations in the geotechnical
report and the approved grading plans not withstanding the testing and
observation of the geotechnical consultant. If, in the opinion of the
consultant, unsatisfactory conditions, such as unsuitable soil, poor
moisture condition, inadequate compaction, adverse weather, etc., are
resulting in a quality of work less than recommended in the opinion of the
consultant, unsatisfactory conditions, such as unsuitable soil, poor
moisture condition, inadequate compaction, adverse weather, etc., are
resulting in a quality of work less than recommended in the geotechnical
report and the specifications, the consultant will be empowered to reject
the work and recommend that construction be stopped until the conditions
are rectified.
Maximum dry density tests used to evaluate the degree of compaction should
be performed in general accordance with the latest version of the American
Society for Testing and Materials test Method ASTM D1557.
3.0 Preparation of Areas to be Filled
3.1 Clearing and Grubbinq: Sufficient brush, vegetation, roots, and all
other deleterious material should be removed or properly disposed of
in a method acceptable to the owner, design engineer, governing
agencies, and the geotechnical consultant.
D-1
8900136-01
SENERAL EARTHWORK AND GRADING SPECIFICATIONS (Cont'd.)
The geotechnical consultant should evaluate the extent of these
removals depending on specific site conditions. In general, no more
than 1 percent (by volume) of the fill material should consist of these
materials and nesting of these materials should not be allowed.
3.2 Processinq: The existing ground which has been evaluated by the
geotechnical consultant to be satisfactory for support of fill, should
be scarified to a minimum depth of 6 inches. Existing ground which
is not satisfactory should be overexcavated as specified in the
following section, scarification should continue until the soils are
broken down and free of large clay Tumps or cTods and until the working
surface is reasonably uniform, flat, and free of uneven features which
would inhibit uniform compaction.
3.3 Overexcavation: Soft, dry, organic-rich, spongy, highly fractured,
or otherwise unsuitable ground, extending to such a depth that surface
processing cannot adequately improve the condition, should be
overexcavated down to competent ground, as evaluated by the
geotechnical consultant. For purposes of determining quantities of
materials overexcavated, a licensed Tand surveyor/civiT engineer should
be utilized.
3.4 Moisture Conditioninq: Overexcavated and processed soils should be
watered, dried-back, blended, and/or mixed, as necessary to attain a
uniform moisture content near optimum.
3.5 Recompaction: Overexcavated and processed soils which have been
properly mixed, screened of deleterious material, and moisture-
conditioned should be recompacted to a minimum relative compaction of
90 percent or as otherwise recommended by the geotechnical consultant.
3.6 Benching: Where fills are to be placed on ground with slopes steeper
than 5:1 (horizontal to vertical), the ground should be stepped or
benched. The lowest bench should be a minimum of 15 feet wide, at
least 2 feet into competent material as evaluated by the geotechnical
consultant. Other benches should be excavated into competent material
as evaluated by the geotechnical consultant. Ground sloping flatter
than 5:1 should be benched or otherwise overexcavated when recommended
by the geotechnical consultant.
3.7 Evaluation of Fill Areas: All areas to receive fill, including
processed areas, removal areas, and toe-of-fill benches, should be
evaluated by the geotechnical consultant prior to fill placement.
4.0 Fill Material
4.1 General: Material to be placed as fill should be sufficiently free
of organic matter and other deleterious substances, and should be
evaluated by the geotechnical consultant prior to placement. Soils
of poor gradation, expansion, or strength characteristics should be
placed as recommended by the geotechnical consultant or mixed with
other soils to achieve satisfactory fill material.
D-2
8900136-01
GENERAL EARTHWORK AND GRADING SPECIFICATIONS (Cont'd.)
4.2 Oversize: Oversize material, defined as rock or other irreducible
material with a maximum dimension greater than 6 inches, should not
be buried or placed in fills, unless the location, materials, and
disposal methods are specifically recommended by the geotechnical
consultant. Oversize disposal operations should be such that nesting
of oversize material does not occur, and such that the oversize
material is completely surrounded by compacted or densified fill.
Oversize materials should not be placed within 10 feet vertically of
finish grade, within 2 feet of future utilities or underground
construction, or within 15 feet horizontally of slope faces, in
accordance with the attached detail.
4.3 Import: If importing of fill material is required for grading, the
import material should meet the requirements of Section 4.1.
Sufficient time should be given to allow the geotechnical consultant
to observe (and test, if necessary) the proposed import materials.
5.0 FiTT Placement and Compaction
5.1 Fill Lifts: Fill material should be placed in areas prepared and
previously evaluated to receive fill, in near-horizontal layers
approximately 6 inches in compacted thickness. Each layer should be
spread evenly and thoroughly mixed to attain uniformity of material
and moisture throughout.
5.2 Moisture Conditioning: Fill soils should be watered, dried-back,
blended, and/or mixed, as necessary to attain a uniform moisture
content near optimum.
5.3 Compaction of Fill: After each layer has been evenly spread, moisture-
conditioned, and mixed, it should be uniformly compacted to not less
than 90 percent of maximum dry density (unless otherwise specified).
Compaction equipment should be adequately sized and be either
specifically designed for soil compaction or of proven reliability,
to efficiently achieve the specified degree and uniformity of
compaction.
5.4 Fill Slopes: Compacting of slopes should be accomplished, in
additional to normal compacting procedures, by backrolling of slopes
with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation
gain, or by other methods producing satisfactory results. At the
completion of grading, the relative compaction of the fill out to the
slope face should be at least 90 percent.
5.5 Compaction Testing: Field tests of the moisture content and degree
of compaction of the fill soils should be performed by the geotechnical
consultant. The location and frequency of tests should be at the
consultant's discretion based on field conditions encountered. In
general, the tests should be taken at approximate intervals of 2 feet
in vertical rise and/or 1,000 cubic yards of compacted fill soils.
In addition, on slope faces, as a guideline approximately one test
should be taken for each 5,000 square feet of slope face and/or each
10 feet of vertical height of the slope.
D-3
8900136-01
GENERAL EARTHWORK AND GRADING SPECIFICATIONS (Cont'd.)
6.0 Subdrain Installation
Subdrain systems, if recommended should be installed in areas previously
evaluated for suitability by the geotechnical consultant, to conform to the
approximate alignment and details shown on the plans or herein. The
subdrain location or materials should not be changed or modified unless
recommended by the geotechnical consultant. The consultant, however, may
recommend changes in subdrain line or grade depending on conditions
encountered. All subdrains should be surveyed by a licensed land
surveyor/civil engineer for line and grade after installation. Sufficient
time shall be allowed for the surveys, prior to commencement of filling over
the subdrains.
7.0 Excavation
Excavations and cut slopes should be evaluated by a representative of the
geotechnical consultant (as necessary) during grading. If directed by the
geotechnical consultant, further excavation, overexcavation, and refilling
of cut areas and/or remedial grading of cut slopes (i.e., stability fiTTs
or slope buttresses) may be recommended.
8.0 Quantity Determination
For purposes of determining quantities of materials excavated during grading
and/or determining the Timits of overexcavation, a licensed Tand
surveyor/civiT engineer shouTd be utilized.
D-4
STABILITY FILL / BUTTRESS DETAIL
OUTLET PIPES
4' 0 NONPERFORATED PiPE.
100* MAX. O.C. HORIZONTALLY,
30' MAX. O.C. VERTICALLY BACK CUT
i. 1:1 OR FLATTER
SEE SUBDRAIN TRENCH
DETAIL
LOWEST SUBDRAIN SHOULD
BE SITUATED AS LOW AS
POSSIBLE TO ALLOW
SUITABLE OUTLET
KEY WIDTH
AS NOTED ON QRADINQ PLANS
15' MIN.
PERFORATED
PIPE
MIN.
EACH SIDE
NON-PERFORATED
OUTLET PIPE
T-COMNECTION DETAIL
6' MIN.
OVERLAP
3/4'-1-1/2'
CLEAN QRAVEL
(3ft.3/ft. MIN.)
4- 0-
NON-PERFORATED
PIPE>^
FILTER FABRIC
ENVELOPE (MIRAFI
140N OR APPROVED
EQUIVALENT)*
SEE T-CONNECTION
DETAIL
4- 0
PERFORATED
PIPE
MIN. }
4' MIN.
BEDDINQ
SUBDRAIN TRENCH DETAIL
*IF CALTRANS CLASS 2 PERMEABLE
MATERIAL IS USED IN PLACE OF
3/4"-1-1/2' QRAVEL, FILTER FABRIC
MAY BE DELETED
SPECIFICATIONS FOR CALTRANS
CLASS 2 PERMEABLE MATERIAL
.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
NOTES:
For buttress dimensions, see geotechnical report/plans. Actual dimensions of buttress and subdrain
may be changed by the geotechnical consultant based on field conditions.
SUBDRAIN INSTALLATION-Subdrain pipe should be installed with perforations down as depicted.
At locations recommended by the geotechnical. consultant, nonperforated pipe should be installed
SUBDRAIN TYPE-Subdrain type should be Acrylonitrile Butadiene Styrene (A.B.S.), Polyvinyl Chloride
(PVC) or approved equivalent. Class 125,SDR 32.5 should be used for maximum fill depths of 36 feet.
Claas 20Qi,8DR 21 should be used for maximum fill depths of ICQ feet.
KEY AND BENCHING DETAILS
FILL SLOPE PROJECT 1 TO 1 LINE
FROM TOE OF SLOPE
TO COMPETENT MATERIAL
EXISTINQ
QROUND SURFACE
REMOVE
UNSUITABLE
MATERIAL
BENCH
2' MIN.
KEY
DEPTH
-^15' MIN. H
LOWEST I LOWEST
BENCH
(KEY)
FiLL-OVER-CUT SLOPE
EXISTING
QROUND SURFACE
REMOVE
UNSUrrABLE
MATERIAL
CUT SLOPE
(TO BE EXCAVATED
PRIOR TO FILL
PLACEMENT)
EXISTINQ
QROUNO
SURFACE-
CUT-OVER-FILL SLOPE
CUT SLOPE
(TO BE EXCAVATED
PRIOR TO FILL
PLACEMENT)
PROJECT 1 TO 1
LINE FROM TOE
OF SLOPE TO
COMPETENT
MATERIAL
REMOVE
UNSUITABLE
MATERIAL
BENCH
MIN'
2' MIN.' l-OWMT
KEY DEPTH ^Jjg^"
NOTE: Back drain may be recommende(j by the geotechnical consultant based on
actual field conditions encountered. Bench dimension recommendations may
alao ba altered based on field conditions encountered.
SIDE HILL STABILITY FILL DETAIL
EXISTING GROUND
SURFACE.
FINISHED SLOPE FACE
PROJECT 1 TO 1 LINE
FROM TOP OF SLOPE TO
OUTSIDE EDGE OF KEY
OVERBURDEN OR
UNSUITABLE
MATERIAL
PAO OVEREXCAVATION DEPTH
AND RECOMPACTION MAY BE
RECOMMENDED BY THE
GEOTECHNICAL CONSULTANT
BASED ON ACTUAL FIELD
CONDITIONS ENCOUNTERED.
COMPETENT BEDROCK OR
MATERIAL AS EVALUATED
BY THE GEOTECHNICAL
CONSULTANT
NOTE: Subdrain details and key width recommendations to be provided based
on exposed subsurface conditions
TRANSITION LOT DETAILS
CUT-FILL LOT
EXISTINQ
QROUND SURFACE
OVEREXCAVATE
AND RECOMPACT
^ COMPETENT BEDROCK
^^OR MATERIAL EVALUATED
r BY THE GEOTECHNICAL
CONSULTANT
CUT LOT
-C^ REMOVE
^UNSUITABLE
MATERIAL
EXISTINQ
QROUND SURFACE
5'
MIN. i
36* MIN.*
AND RECOMPACT
COMPETENT BEDROCK
OR MATERIAL EVALUATED
BY THE QEOTECHNlCAL
CONSULTANT
*NOTE:
Deeper or laterally more extensive overexcavation and
recompaction may be recommended by the geotechnical
consultant based on actual field conditions encountered
and locations of proposad improvements
CANYON SUBDRAIN DETAILS
BENCHING
REMOVE
UNSUITABLE
MATERIAL
SUBDRAIN
TRENCH
SEE BELOW
SUBDRAIN TRENCH DETAILS
6* MIN. OVERLAP
FILTER FABRIC ENVELOPE
^(MIRAFI 140N OR APPROVED
EQUIVALENT)* A
6' MIN. OVERLAP
3/4'-1-1/2' CLEAN
GRAVEL (9ft.3/ft. MIN.)
6' 0 MIN.
PERFORATED
PIPE
3/4'-1-1/2' CLEAN
GRAVEL
(Oft.^/ft. MIN.)
•IF CALTRANS CLASS 2 PERMEABLE
MATERIAL IS USED IN PLACE OF
3/4-1-1/2' QRAVEL, FILTER FABRIC
MAY BE DELETED
DETAIL OF CANYON SUBDRAIN TERMINAL
DESIGN FINISH
GRADE SUBDRAIN
TRENCH
SEE ABOVE
PERFORATED
6' 0 MIN. PIPE
NONPERFORATED S' 0 MIN.
SPECIFICATIONS FOR CALTRANS
CLASS 2 PERMEABLE MATERIAL
U.S. Standard
Sieve Size % Passinq
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
Subdrain should be constructed only on competent material as evaluated by the geotechnical
conaultant.
SUBDRAIN INSTALLATION Subdrain pipe should be instailed with perforations down as depicted.
At locations recommended by the geotechnical consultant, nonperforated pipe shouid be installed.
SUBDRAIN TYPE-Subdrain type should be Acrylonitrile Butadiene Styrene (A.B.S.). Polyvinyl
Chloride (PVC) or approved equivalent. Class 125, SDR 32.5 should be used for maximum
flll depths of 35 feet. Class 200,SDR 21 should be used for maximum flli depths of 100 feet.
ROCK DISPOSAL DETAIL
FINISH GRADE
SLOPE FACE
GRANULAR SOIL <8-E-^ 12Jff^ DENSIFIED IN PLACE BY FLOODING DETAIL
TYPicAL PROFILE ALONG WINDROW
and 15 feet horizontally of slope facee.
2) Rocks with maximum dimensions greater than 4 feet should not be utilized in fills.
3) Rock placement, flooding of granular soil, and fill placement should be observed by thei
geotechnical consultant. I
A n# windrows Should be in accordance with the above details
4) Maximum size and apac ng of ^'"^'^ should be staggered
Width of windrow should not exceea looi. winuiuw-
vertically (aa depicted).
rocks.
RETAINING WALL DRAINAGE DETAIL
f SOIL BACKFILL. COMPACTED TO
90 PERCENT RELATIVE COMPACTION*
RETAINING WALL
WALL WATERPROOFING
PER ARCHITECT'S
SPECIFICATIONS
FILTER FABRIC ENVELOPE
(MIRAFI 140N OR APPROVEO
EQUIVALENT)**
3/4'-1-1/2' CLEAN GRAVEL**
4' (MIN.) DIAMETER PERFORATED
PVC PIPE (SCHEDULE 40 OR
EQUIVALENT) WITH PERFORATIONS
ORIENTED DOWN AS DEPICTED
MINIMUM 1 PERCENT GRADIENT
TO SUITABLE OUTLET
SPECIFICATIONS FOR CALTRANS
CUSS 2 PERMEABLE MATERIAL
U.S. Standard
Sieve Size X Passinq
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 Equiva1ent>75
3' MIN.
COMPETENT 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* QRAVEL. FILTER FABRIC MAY BE
DELETED. CALTRANS CLASS 2 PERMEABLE
MATERIAL SHOULD BE COMPACTED TO 90
PERCENT RELATIVE COMPACTION *
NOT TO SCALE