HomeMy WebLinkAbout; Vista/Carlsbad Interceptor Sewer/Oak Storm Dr; Vista/Carlsbad Interceptor Sewer/Oak Storm Dr; 1982-08-31SUPPLEMENTAL PRELIMINARY
GEOTECHNICAL INVESTIGATION
CARLSBAD RESEARCH CENTER
COLLEGE BOULEVARD AND
"D" STREET ALIGNMENTS
CARLSBAD, CALIFORNIA
PREPARED FOR
CARLSBAD RESEARCH CENTER
7330 ENGINEER ROAD
SAN DIEGO, CALIFORNIA 92111
PREPARED BY
SAN DIEGO SOILS ENGINEERING, INC,
4891 MERCURY STREET
SAN DIEGO, CALIFORNIA 92111
AUGUST 31, 1982
JOB NO: SD1163-00
LOG NO: SD2-2W
TABLE OF CONTENTS
Page
I. INTRODUCTION 1
II. SITE PEl/ELOPMENT 1
III. SCOPE OF SERVICES 2
It/. SITE DESCRIPTION 3
I/. FIELP INVESTIGATION 5
I/I. LABORATORY TESTING 6
VII. GEOLOGY 7
A. Regional Geology 7
B. Geologic Units 7
1. Santiago Peak Volcanics (map symbol.JsP) 7
2. Point Loma Formation (map symbol Kpl) . 8
3. Santiago Formation (map symbol-Tsa) . . 8
4. Quaternary Terrace Deposits (map
symbol Qt) 9
5. Alluvium (map symbol-Qal) 10
6. Landslide 10
7 Fill 11
C. Structural Geology 11
D. Ground Water 11
via. sEisMiciry 13
A. Regional Seismicity 13
B. Earthquake Effects 13
1. Earthquake Accelerations 13
2. Settlement of Soils 14
3. Liquefaction 14
4. Lurching and Shallow Ground Rupture . . 14
IX. ENGINEERING CONSIDERATIONS 15
A. General Description of Soils/Bedrock. ... 15
1. Santiago Peak Volcanics 15
2. Point Loma Formation 15
3. Santiago Formation 16
4. Topsoil 17
5. Alluvium 17
TABLE OF CONTENTS
(continued)
Page
B. Remedial Grading 18
1. Unsuitable Soils 18
2. Stabilization 18
3. Slopes 19
C. Expansive Soils 19
X. CONCLUSIONS ANP RECOMMEWPATIOWS 20
A. General 20
B. Slope Stability 20
1. Fill Slopes 20
2. Cut Slopes 21
a. Santiago Peak Volcanics 21
b. Point Loma Formation 22
c. Santiago Formation 23
d. Quaternary Terrace Deposits .... 24
3. Fill-Over-Cut Slopes 24
4. Stabilization/Buttress Fills 24
5. Construction Slopes 25
6. Natural Slopes 25
C. Treatment of Alluvium 25
D. Grading and Earthwork 26
1. Inspection 26
2. Clearing and Grubbing 27
3. Site Preparation 27
a. Treatment of Surface Soils 27
b. Existing Fill Soils 27
c. Treatment of Alluvium 28
d. Scarification and Processing of
Surface Soils 28
4. Compaction and Method of Filling. ... 28
5. Selective Grading 29
6. Import Fill Material 30
7. Shrinkage, Bulking and Subsidence ... 31
8. Transition Lots 31
TABLE OF CONTENTS
(continued)
Page
E. Restriction on Future Construction 32
F. Surface and Subsurface Drainage 33
G. Retaining Walls 34
H. Type of Cement for Construction 35
I. Pavements 35
J. Utility Trench Backfill 36
K. Grading Plan Review 36
L. Limitations of Investigation 37
APPENPIX A - REFERENCES
APPENDIX B - SUBSURFACE EXPLORATION
APPENPIX C - LABORATORY TESTING
APPENPIX V - SLOPE STABILITY ANALYSES
APPENPIX E - STANPARP GUIPELINES FOR GRAPING PROJECTS
PLATES T S 2 - GEOTECHNICAL MAPS
PLATE 3 - GEOLOGIC CORSS SECTIONS
SAN DIEGO SOILS ENGINEERING, INC.
SOIL ENGINEERING & ENGINEERING GEOLOGY
August 31, 1982
Carlsbad Research Center
7330 Engineer Road
San Diego, California 92111
Job No:
Log No:
SD1163-00
SD2-2484
Attention:
SUBJECT:
Mr. Michael J. Dunigan
SUPPLEMENTAL PRELIMINARY GEOTECHNICAL INVESTIGATION
Carlsbad Research Center
College Boulevard and "D" Street Alignments
Carlsbad, California
Gentlemen:
We are pleased to present the results of our Supplemental
Preliminary Geotechnical Investigation of College Boulevard
and "D" Street alignments, for the Carlsbad Research Center,
Carlsbad, California. The accompanying report presents the
results of our evaluation of the on-site geotechnical conditions
and recommendations for the development of the site.
The opportunity to be of service is sincerely appreciated. If
you have any questions, please contact this office.
Very truly yours,
SAN DIEGO SOILS ENGINEERING, INC.
Sj.
$Cw^<s
rv/fr. Stoney /
President
GFS: tin
SUBSIDIARY OF IRVINE CONSULTING GROUP, INC.
4891 MERCURY STREET.SAN DIEGO, CA 92111 .(714) 268-8266
SUPPLEMENT PRELIMINARY GEOTECHNICAL INVESTIGATION
CARLSBAD RESEARCH CENTER
COLLEGE BOULEVARD AND "D" STREET ALIGNMENTS
CARLSBAD, CALIFORNIA
I. INTRODUCTION
This report presents the results of our Supplemental Pre-
liminary Geotechnial Investigation of College Boulevard
and "D" Street alignments for the Carlsbad Research Center
development, located in Carlsbad, California. Our investi-
gation was performed to provide geotechnical data to aid
in the planning and development of College Boulevard in
Phase IV and "D" Street offsite, south of Phase III.
We were provided with 80 scale and 100 scale Grading Plans
prepared by Rick Engineering Company. These grading plans
were utilized as the base map for the attached Geotechnical
Maps, Plates 1 and 2. Our investigation was directed toward
development as shown on the grading plans.
II. SITE PEl/ELOPMENT
The proposed development consists of grading in the areas
of the street alignments, utilizing conventional cut and
fill grading techniques. The purpose of this grading is
to develop through streets to the north and south of
Carlsbad Research Center, Phase II and III. Several build-
ing pads in Phase IV will be partially graded in conjunction
with the northern extension of College Boulevard.
The locations of the proposed streets are shown on the
attached Geotechnical Maps, Plates 1 and 2, and Location
Map, Figure 1.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Two
III. SCOPE OF SERVICES
The scope of services provided during the preparation of
this Supplemental Preliminary Geotechnical Investigation
included:
A. Review of previous geologic, soils engineering and
seismological reports and maps pertinent to the pro-
ject area (See Appendix A);
B. Analysis of stereographic aerial photographs to evaluate
the topography and geologic structure of the area
(See Appendix A);
C. Geologic mapping of existing exposures and outcrops;
D. Subsurface exploration, including ten bucket auger
borings to a maximum depth of 70 feet, 35 backhoe
test pits excavated to a maximum depth of 15 feet and
three dozer pits;
E. Logging and sampling of exploratory excavations to
evaluate the geologic structure and to obtain ring
and bulk samples for laboratory testing;
F. Laboratory testing of samples representative of those
obtained during the field investigation;
G. Geologic and soils engineering analysis of field
and laboratory data which provide the basis for our
conclusions and recommendations;
H. Preparation of this report and accompanying maps, cross
sections and other graphics presenting our findings,
conclusions and recommendations.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Three
IV. SITE INSCRIPTION
The street alignments involved in this investigation consist
of two separate sites. The northern site is a portion of the
proposed Phase IV, Carlsbad Research Center. The southern
site is located south of the proposed Phase III, Carlsbad
Research Center and is a portion of the proposed Airport
Business Center. The approximate locations and topography
of the sites are shown on the attached Location Map,
Figure 1.
Topographically, the northern street alignment area consists
of a number of ridges with moderate, to steep relief near
the base of the ridges. Letterbox Canyon is the major
drainage course east of and adjacent to the ridges and
proposed street alignment. This canyon trends north-south,
draining towards El Camino Real to the north. Previous
brick manufacturing and clay mining have modified one of the
north-west ridges and left some concrete structures. Access
to this area is by dirt roads from El Camino Real near
Letterbox Canyon and by dirt roads from Carlsbad Research
Center, Phase I.
The southern street alignment topography consists of ridges
and relatively small canyons, with gently to moderately
sloping terrain. Locally steep terrain exists in the
canyon in the vicinity of "D" Street. Access to this area
is by dirt roads from Palomar Airport Road and from Carlsbad
Research Center, Phase I. Underground pipelines are present
in existing easements crossing the site.
4000 Adapted from U.S.Q.S. 7.5" Encinifas and San Luis Rey
Quadrangle, 1976
LOCATION MAP-COLLEGE BLVD. AND "D" STREET-CARLSBAD, CALIFORNIA
JOB NO.:SD1163-00 DATE:AUGUST 1982 FIGURE:
1
SAN DIEQO SOILS ENGINEERING. INC.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Four
At the time of our investigation, a heavy growth of tall
grasses and high weeds covered most of the northern site.
The southern site is covered by low grasses and chaparral.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
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I/. flELV IWl/ESTIGATIOW
The field investigation performed during the course of
this investigation consisted of geologic reconnaissance,
mapping and subsurface investigation consisting of ten
drilled bucket anger borings, thirty-five backhoe test
pits and three bulldozer trenches. The field investigation
was conducted under the direct supervision of our Engineering
Geologist.
A truck-mounted bucket auger drill rig was used to drill
ten 24-inch diameter borings to a maximum depth of 70 feet.
The borings were sampled, downhole logged and back-filled,
with samples returned to the laboratory for testing. Logs
of the borings are presented in Appendix B.
A tractor-mounted backhoe and a bulldozer were used to
excavate thirty-five test pits and three dozer test
trenches respectively. The backhoe pits were excavated
to a maximum depth of fifteen feet and the dozer trenches
were excavated to a maximum depth of six feet and a max-
imum length of 240 feet. The backhoe pits and dozer
trenches were logged and the excavations were back-filled.
Logs of the excavations are presented in Appendix B.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Six
I/I. LABORATORV TESTING
Samples representative of the earth materials encountered
during our field investigation were returned to the labor-
atory for testing. The testing program consisted of mois-
ture-density determinations, direct shear testing of
ring and remolded samples, maximum density-optimum
moisture determinations, Atterberg Limits, expansion tests,
consolidation tests and particle size analyses.
Results and descriptions of the laboratory tests performed
are included in Appendix C.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Seven
VII . GEOLOGV
A. Regional Geology
The subject site is located in the Peninsular Ranges
Geomorphic Province of California near the western
margin of the Southern California Batholith. At the
edge of the batholith the topography changes from the
typically rugged landforms developed over the granitic
rocks to the flatter, more subdued landforms under-
lain by sedimentary bedrock associated with the coastal
plain.
The site is underlain by Jurassic metavolcanics and
Cretaceous, Eocene and Quaternary sediments. Alluvial
sediments are present in the canyon bottoms.
A brief description of the geologic units 'observed
within the site follows. The distribution of the
geologic units is shown on the attached Geotechnical
Maps, Plates 1 and 2.
B. Geologic Units
1. Santiago Peak Volcanics (map symbol-Jsp)
The Jurassic Age Santiago Peak Volcanics underlie
a portion of the southern site. The Santiago
Peak Volcanics are mildly metamorphosed volcanic,
or metavolcanic rocks. Regionally the Santiago
Peak Volcanics vary from basalt to rhyolite but
on-site they are predominantly andesite.
Carlsbad Research Center Job No: SD1163-00
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Page Eight
Excavation in the Santiago Peak Volcanics is
difficult. The weathered material within about
three feet of the existing ground surface can
generally be excavated with conventional heavy
earth-moving equipment. Below that depth heavy
ripping and blasting would be anticipated. Heavy
ripping or even blasting would generally produce
oversize materials which can be considered addi-
tional cost items because of difficulty in handling.
2. Point Loma Formation (map symbol-Kpl)
The Cretaceous Age Point Loma Formation consists
of a marine interbedded fossiliferous siltstone
and claystone with locally cemented sandstone
lenses. The Point Loma Formation observed on-site
is generally flat lying with local dips of up to
five degrees. The siltstone and claystone are
stiff to very stiff, but weather readily to a
loose mass. Point Loma Formation materials
underlie most of the northern street alignment area.
Excavation in the Point Loma Formation can be
accomplished with conventional heavy earth-moving
equipment. Heavy ripping may be required in some
of the very stiff materials at depth. The soils
produced are reusable as fill material and are
moderately to highly expansive.
3. Santiago Formation (map symbol-Tsa)
The Eocene Age Santiago Formation consists of
interbedded fine sandstone, siltstone and clay-
stone. It is generally stiff or dense and massive
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Nine
to poorly bedded. The Santiago Formation overlies
both the Point Loma Formation and the Santiago
Peak Volcanics. The contact with these units
appears to be irregular. The bedding is usually
horizontal with local dips as high as ten degrees.
In the southern street alignment area the fine
sandstone appears to be the predominant lithology,
with clayey and silty lenses. The northern exten-
sion of College Boulevard area contains Santiago
Formation that is predominantly a siltstone, with
clayey and sandy lenses.
Excavation in the Santiago Formation can be accom-
lished with conventional heavy earth-moving equip-
ment. No significant cemented zones were encountered
in the borings or test pits, therefore, heavy
ripping or blasting are not anticipated. When
utilized as fill materials, the expansion potential
will range from low to high.
4. Quaternary Terrace Deposits (map symbol-Qt)
Quaternary Terrace Deposits overlie the Santiago
Peak Volcanics and the Santiago Formation, on the
upper elevation ridges of the southern College
Boulevard and "D" Street area. The terrace deposits
are relatively thin and consist of a reddish sand
with cobbles.
Excavation in the terrace deposits can be accom-
plished with conventional heavy earth-moving equip-
ment.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Ten
5. Alluvium (map symbol-Qal)
Alluvium is present in the canyon areas of both
the northern and southern sites. The most exten-
sive alluvial area, Letterbox Canyon, is located
adjacent to the northern extension of College
Boulevard. Minor amounts of alluvium are located
in the small canyon in the vicinity of "D" Street,
in the southern site.
The alluvium in Letterbox Canyon and it's tribu-
taries consists of a moist, soft sandy and silty
clay, with saturation occuring just above the bed-
rock contact below. The alluvium was observed to
a maximum depth of 24 feet in Boring 7.
Landslide
A previous geotechnical investigation of the site
indicates a landslide in the vicinity of the north-
ern ridge, in the College Boulevard northern exten-
sion. Based on our geotechnical investigation,
we have concluded that a landslide does not exist
in that area, located along Cross Section A-A1
(Geotechnical Map, Plate 1) and Geologic Cross
Sections, Plate 3 . The conditions found in our
subsurface explorations indicate that the ridge is
underlain by the Santiago Formation and the Point
Loma Formation, with a fault trending northeast
across the ridgeline. Aerial photographs, taken
before the brick manufacturing had begun in the
area, show that some grading has taken place on
the ridge.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Eleven
7. Fill
Fill is present in the northern alignment at
College Boulevard. The fill is associated with
previous minor grading for structures and roads
used in a brick manufacturing operation.
C. Structural Geology
The predominant structural features within this portion
of the Peninsular Ranges Geomorphic Province are assoc-
iated with pre-Tertiary folding along north-south axes.
The post-Cretaceous sequences have been folded and
tilted generally to the west.
Discontinuous northeast trending faulting is associated
with the post-Cretaceous folding. Faulting has been
mapped in the north College Boulevard areas. The
faulting observed in our test pits does not offset
topsoil materials, and no topographic surface offsets
were observed. The faulting, as mapped by others and
ourselves, is considered inactive and does not pose a
significant hazard to the proposed development. The
closest active fault is the Elsinore Fault Zone located
22 miles to the northeast. Locations of the faulting
on-site are shown on the Geotechnical Map, Plate 1.
D. Ground Water
Ground water was encountered in alluvial areas and in the
bedrock. In the alluvial areas, specifically Letterbox
Canyon, ground water was encountered perched above the
bedrock contact. Borings into the bedrock encountered
ground water seepage perched above very massive,
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Twelve
unweathered strata. Both of these ground water
conditions represent locally perched conditions and
do not reflect regional ground water conditions.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Thirteen
l/III.SEISMICiry
A. Regional Seismicity
The site can be considered a seismically active area,
as can all of southern California. There are, however,
no active faults on or adjacent to the site. Seismic
risk is considered low, as compared to other areas of
southern California, due to the distance from active
faults.
Seismic hazards within the site can be attributed
to ground shaking resulting from events on distant
active faults. Listed on Table I are the active
faults which can significantly affect the site.
Figure 2 shows the geographic relationship of the site
to these faults.
B. Earthquake Effects
1. Earthquake Accelerations
We have analyzed the possible earthquake accel-
erations at the site and, in our opinion, for the
intended use, the most significant event is a
7.0 Magnitude earthquake located on the Elsinore
Fault Zone. The accelerations produced at the
site by such an event would exceed those events
which might occur on other known active faults.
A Magnitude 7.0 earthquake on the Elsinore Fault
Zone could produce a peak ground acceleration of
0.22g at the subject site with the duration of
strong shaking exceeding 30 seconds. Peak accel-
TABLE I
FAULT
Elsinore
Newport-Inglewood
San Jacinto
San Andreas
SEISMICITY
DISTANCE
FROM SITE
22 Miles NE
40 Miles NW
45 Miles NE
66 Miles NE
FOR MAJOR FAULTS
MAXIMUM PROBABLE,
EARTHQUAKE
7.0
6.5
7.5
8.0
ESTIMATED
PEAK BEDROCK,
ACCELERATION
0.22g
0.06g
O.llg
0.09g
1. Seismic Safety Study, City of San Diego (1974 and Bonilla 1970)
2. Schnabel and Seed (1973)
- —«B
Adapted from: Geology, Selsmlclty and
Environmental Impact, Special Publication
of the Association of Engineering
Geologist, 1973
MAJOR EARTHQUAKES AND RECENTLY ACTIVE FAULTS
IN THE SOUTHERN CALIFORNIA REGION
EXPLANATION"
ire
ACTIVE FAULTS EARTHQUAKE LOCATIONS
Approximate epicentral areo of earthquakes that
occurred I769-I933. Magnitudes not recorded
by instruments prior to 1906 were estimated
from damage reports assigned an Intensity VII
(Modified Mercali scale) or greater, this is roughly
equivalent to Richter M 6.0. 31 moderate"
earthquakes, 7 major and one great earthquake
(I857) were reported in the 164-year period
1769-1933.
Total length of fault zone that breaks Holocene deposits
or that has had seismic activity
Fault segment with surface rupture during on historic
earthquake, or with aseismic fault creep.
Earthquake epicenters since 1933, plotted from
improved instruments 29 moderate** and three
major earthquakes were recorded in the 40-year
period 1933-1973.
Holocene volcanic activity
(Amboy, Pngah, Cerro Prieto and Solton Buttes)REGIONAL FAULT MAP
SAN DIEGO SOILS ENGINEERING. INC.
• SM Lomor, Ntrrfiild, Proctor poptr htnin ftr iMillonol liplonalion of mop.
•• Codt rtcoMiufldations bi KM Structural Enginiori Association of California 4ttini a frtal oarthquokt as ana tkathat a Rlcktar Mooml,d, at 7% or >riot«: a naior nnhayaki 7 to 7% ; a Mdarali aartk«M>a 6 to 7.
Compiled by Riclwd J Proctor moinli from published and unpublished data of ttw Ca/ifoma Dirnan of Mines and Gtotogjr, California Dtportmtft
of Hater Resa/ms Bulletin 116-2 \ 1964): selections from bulletins of tt« geological and Seamologial Societies of America; from t F. Richltr,
Seisnotofr(\95a); and the HatioialMhs p.66.JOB NO.: IOATE: FIGURE NO.:
SD1163-OO JULY 1882 2
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Fourteen
erations are not, however, representative of the
accelerations for which structures are actually
designed. Design of structures should be com-
pleted in compliance with the requirements of
the governing jurisdictions and standard practices
of the Structural Engineers Association of
California.
2. Settlement of Soils
The earth materials underlying the site consist
primarily of firm sedimentary bedrock which should
not be subject to seismically induced settlement.
Topsoil and areas of uncompacted fill will be
removed and compacted during grading. Remedial
treatment of alluvial soils will also be recom-
mended .
3. Liquefaction
The bedrock materials underlying the site have a
very low to non-existent potential for lique-
faction. Alluvial areas will be treated during
grading.
4. Lurching and Shallow Ground Rupture
Breaking of the ground because of active faulting
is not likely to occur on the site due to the
absence of active faults. Cracking due to shaking
from distant events is not considered a significant
hazard, although it is a possibility at any site.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Fifteen
IX. ENGINEERING CONSIDERATIONS
A. General Description of Soils/Bedrock
Our investigation indicates that materials at the
subject site consist of Santiago Peak Volcanics,
Point Loma Formation and Santiago Formation bedrock
overlain with clayey topsoil or alluvium. Fill
derived from the Point Loma Formation and Santiago
Formation bedrock will be the predominant materials
encountered during grading. Brief discussions of
the significant engineering characteristics of the
various material types are presented below:
1. Santiago Peak Volcanics
Santiago Peak Volcanics underlying the site
consist of hard, non-rippable rock. However,
the Santiago Peak Volcanics are located in
proposed fill areas and rock hardness should not
significantly effect grading operations.
2. Point Loma Formation
The Point Loma Formation bedrock consists pre-
dominantly of interbedded siltstone and clay-
stone. Typical index and engineering properties
are presented in Table 2. Remolded Point Loma
Formation bedrock typically has a high expansion
index and low shear strength parameters. The
engineering characteristics of this material will
result in flatter slopes and heavy pavement
sections.
TABLE 2
Typical Index and Engineering Properties
of Point Loma Formation Siltstone/Claystone
Index Properties
Natural Total Unit Weight (pcf)
Natural Dry Density (pcf)
Water Content (%)
Unified Soil Classification
(Remolded Siltstone)
125 - 5
105 - 5
20-2
Clay of Low Plasticity
(CL)
Engineering Properties
Remolded Drained Shear Strength
(Siltstone)*
Cohesion (psf)
Friction Angle
(degrees)
c =400
24
Intact Shear Strength
(siltstone/claystone)
Cohesion (psf) c = 400
Friction Angle 0 = 32
(degrees)
Expansion Potential
(Remolded Siltstone)High
* Applicable to normal stress range of 1000-4000 psf and
remolded at 90% maximum dry density.
Carlsbad Research Center Job No: SD1163-00
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Page Sixteen
It is expected that Point Loma Formation bedrock
may be excavated utilizing conventional equip-
ment. The fill material derived from excavation
should be generally blocky requiring considerable
effort to break the material down into a uniform
compacted fill. During grading of the first
phase of the Carlsbad Research Center project,
a Cat-825 steel-wheel compactor or a D8 dozer
and 5x5 sheepsfoot, in combination with rubber
tire earth-moving equipment, worked reasonably
well in breaking down the blocky material and
creating a relatively uniform compacted fill
condition.
3. Santiago Formation
As mentioned, the Santiago Formation overlies
both the Point Loma Formation and the Santiago
Peak Volcanics. The Santiago Formation consists
of interbedded fine sandstone, siltstone and
claystone. Along the "D" street alignment, the
exposed material is anticipated to be predominantly
fine sandstone. In the northern extension of
College Boulevard, the exposed material is
anticipated to be predominantly siltstone.
Typical grain size curves for the Santiago Clay-
stone and Sandstone are shown in Figures C-l and
C-2 (Appendix C) respectively. Index and Engi-
neering properties of the Santiago Formation bed-
rock are presented in Table 3. Remolded Santiago
Formation siltstone/claystone typically has a
high expansion potential and low shear strength,
TABLE 3
Typical Index and Engineering Properties
of Santiago Formation
Index Properties
Natural Total Unit Weight (pcf)
Natural Dry Density (pcf)
Water Content (%)
Unified Soil Classification
Remolded Sandstone
Remolded Claystone
124 - 5
110 - 5
13 ± 2
Silty Fine Sand (SM)
Clay of High Plasticity (CH)
Engineering Properties
Peak Shear Strength
(Intact Sandstone)
Remolded Drained Shear
Strength (Sandstone) *
Remolded Shear Strength
(Claystone) *
Expansion Potential
Cohesion (psf)
Friction Angle
Cohesion (psf)
Friction Angle
Cohesion (psf)
Friction Angle
c = 650
0 = 31°
c = 200
$ = 32°
c = 850
0 = 17°
Remolded Claystone/Siltstone High
Remolded Sandstone Low-Medium
*Applicable to normal stress range of 1000-4000 psf and
remolded to 90% maximum dry density.
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Page Seventeen
parameters which will result in flatter slopes
and heavy pavement sections. Remolded Santiago
Formation sandstone typically has a low to
medium expansion potential and higher shear
strength. It is expected that thinner pavement
sections will be needed for those portions of
the roads constructed in the sandstone.
4. Topsoil
Overlying the bedrock is typically a two to five
foot thick layer of clayey topsoil. The top-
soil is generally loose or soft in the upper two
(-) feet and becomes firmer with depth. The
topsoil is classified as a clay of high plasticity
(CH), with low shear strength and a very high
expansion potential. Topsoil material is con-
sidered an undesirable bearing material due to
its engineering properties. Recommendations for
remedial grading of the topsoil will be provided.
5. Alluvium
At some locations, especially in the canyon areas,
alluvium overlies bedrock. A typical grain size
curve for alluvium is presented in Figure C-4
(Appendix C) and the material is classified as
a clay of low plasticity (CL). Two consolidation
tests performed on alluvium (Figures C-8 and
C-9) indicate that it is highly compressible.
The alluvium is considered an undesirable material
requiring remedial grading. Removal of alluvium
will be recommended except for the alluvium
Carlsbad Research Center Job No: SD1163-00
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Page Eighteen
located in a portion of Letterbox Canyon. One
method to improve the engineering performance of
the in-place alluvium would be to surcharge it.
The surcharge would compress the alluvium and
mitigate the potential for future settlements
resulting from foundation loads.
B. Remedial Grading
1. Unsuitable Soils
With the exception of the alluvium in Letterbox
Canyon, topsoil and alluvium will have over-
excavation recommended, along with selective
replacement as compacted fill. Alluvium materials
were encountered during our field exploration
and are approximately delineated on the accompanying
plan. The depths of the alluvium are indicated
in the excavation logs. Moist to saturated con-
ditions were encountered within the alluvial soils
and may be expected during grading. Moisture
conditioning of wet alluvium and/or dry topsoil
may require special equipment and can be expected
to slow production in the early stages of grading.
2. Stabilization Fills
Stabilization fills are typically recommended to
enhance the stability of locally adverse geologic
conditions. Stabilization consists of overex-
cavating the slope face and replacement with a
uniform compacted fill. Stabilization recommenda-
tions can be expected for cuts within the Point
Loma Formation and Santiago Formation.
Carlsbad Research Center Job No: SD1163-00
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Page Nineteen
3. Slopes
Slope stability analyses were performed for the
proposed cut and fill slopes. Results of slope
stability analyses (Appendix D) indicate that
2:1 (horizontal:vertical) slopes would possess
an acceptable factor of safety against gross
instability. However, 2:1 (horizontal:vertical)
slopes comprised of Point Loma Formation silt-
stone or Santiago Formation siltstone/claystone
would not possess an acceptable factor of safety
against surficial instability. Options to
improve the surficial stability include laying
the slope back to a flatter slope ratio (i.e. 2.5:1)
or facing the outer portion of slopes (i.e. 12
feet) with select materials. The suitability of
individual sources of proposed select material
would require evaluation. Suitable sources are
expected to be comprised of predominantly granular
soil with minor fractions of silt and clay. The
Santiago Formation sandstone or D.G. would be
appropriate.
C. Expansive Soils
Results of expansion tests indicate that fill derived
from the on-site materials could cause heaving/cracking
of concrete walks, driveways, roads, etc. The pre-
dominance of expansive soils will result in heavy
pavement sections in most areas.
Carlsbad Research Center Job No: SD1163-00
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Page Twenty
X. CONCLUSIONS ANP RECOMMENDATIONS
A. General
Based on the results of our Supplemental Preliminary
Geotechnical Investigation, we conclude that the
project is feasible from a geotechnical standpoint.
There are, however, two salient geotechnical conditions
which will require special treatment: stability of
proposed cut and fill slopes and the presence of
deep alluvial deposits in the canyon bottoms. Although
these conditions will necessitate special remedial
measures, they can be sucessfully treated during the
mass grading of the site. We conclude that the
proposed development is feasible, from a geotechnical
standpoint, provided the following conclusions and
recommendations are incorporated into the project
plans and specifications.
B. Slope Stability
1. Fill Slopes
Permanent fill slopes are proposed on-site to
a maximum height of about 55 feet. A fifty-
five foot high fill slope constructed at a slope
ratio of 2:1 (horizontal:vertical) should
posses gross stability in excess of the generally
accepted minimum engineering criteria. 2:1
(horizontal:vertical) fill slopes constructed
of predominantly Point Loma Formation derived
fill material will be subject to surficial
instability. Fill slopes in excess of ten feet
in height should be provided with at least ten
Carlsbad Research Center Job No: SD1163-00
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Page Twenty-One
feet of select material on the slope face or
laid back to 2.5:1 (horizontal;vertical) or
flatter to enhance surficial slope stability.
Proposed slopes subject to this recommendation
are indicated on the attached Figure 3 & 3A.
Fill slopes more than thirty feet in height
shall have drainage terraces provided at vertical
intervals not exceeding twenty-five (25) feet.
For fill slopes in excess of one hundred (100)
feet, a terrace drain not less than twenty (20)
feet wide shall be required near mid-height.
Temporary fill slopes at 3:1 (horizontal:
vertical) are proposed along the extension of
"D" Street. Because these temporary slopes may
be subjected to several winters before grading
is completed, they should be built to the same
standards as permanent slopes.
Fill slopes should be constructed in accordance
with the recommendations herein and the Standard
Guidelines for Grading Projects which are
attached as Appendix E. It is recommended that
fill slopes at 2:1 (horizontal:vertical) less
than ten (10) feet in height be constructed by
overfilling and cutting back to the compacted core.
2. Cut Slopes
a. Santiago Peak Volcanics
No significant cut-slopes are proposed in
the Santiago Peak Volcanics.
Approximate scale 1* : 325'
o Slopes subject to surficial
stabilization or 2.5:1 layback
AREAS SUBJECT TO SURFICIAL STABILIZATION OR LAYBACK
JOB NO.:1163-00 DATE:AUGUST 1982 FIGURE:
SAN DIEGO SOILS ENGINEERING, INC.
Slopes subject to surficial
stabilization or 2.5:1 layback
AREAS SUBJECT TO SURFICIAL STABILIZATION OR LAYBACK
JOB NO.:1163-00 DATE:AUGUST 1982 FIGURE;
3A
SAN DIEGO SOILS ENGINEERING. INC.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Twenty-Two
Point Loma Formation
The orientations of proposed cut-slopes in
the Point Loma Formation are generally
favorable with respect to the geologic
structure and bedding planes. It is antic-
ipated that ground water conditions will,
however, necessitate remedial grading in
the form of stabilization fills for most
cut-slopes in Point Loma Formation materials.
Final determination of the need for stabili-
zation will be made by the Geotechnical
Consultant during grading. Continuous
observation of the cuts in progress is
essential. The stabilization fills will
be constructed with a key width equal to
one-half of the slope height. Drainage
devices will be required behind the stabili-
zation fills. Typical details for stabili-
zation fills and drainage devices are
presented in the attached Appendix E,
Standard Guidelines for Geotechnical Projects.
Weathering characteristics of the Point
Loma Formation materials will necessitate
special treatment to mitigate surficial
stability concerns on cut-slopes. The Point
Loma Formation materials weather or slake
rapidly, generally loosing integrity when
exposed in excavations. The rapid deteri-
oration of the cut-slope face will necessitate
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Twenty-Three
mitigation measures identical to those
previously recommended for fill slopes
made of Point Loma Formation materials,
(e.g. blanket stabilization fills of select
materials or reduced slope ratios).
c. Santiago Formation
Subsurface exploration indicates that the
proposed one hundred (100) foot high cut-
slope near the intersection of College
Boulevard and El Camino Real will expose
materials which are considered unsuitable
from a long term slope stability standpoint.
It is anticipated that a stabilization fill
with a key width equal to one-half the slope
height will be recommended at this location.
The stabilization fill should be constructed
with backdrains in accordance with the
typical details in the attached Appendix E,
Standard Guidelines for Geotechnical Pro-
jects. Final determination of the require-
ment for stabilization will be made by the
Geotechnical Consultant during grading.
Continuous geologic observation of the cuts
in progress is essential.
Minor cut-slopes in Santiago Formation
materials are proposed along the southerly
extension of College Boulevard and "D"
Street. It is not anticipated that these
slopes will need any type of stabilization.
Final determination of the requirement for
stabilization will be made during grading.
Carlsbad Research Center Job No: SD1163-00
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Page Twenty-Four
d. Quaternary Terrace Deposits
The Quaternary Terrace Deposits will be
exposed in the upper portion of slopes
proposed along the extension of "D" Street.
It is not anticipated that stabilization
measures will be required in these areas.
Final determination of the need for stabili-
zation will be made in the field by the
Geotechnical Consultant during grading.
3. Fill-Over-Cut Slopes
Where fill-over-cut slopes are proposed, it is
recommended that the cut portion be completed
prior to fill placement. An equipment width
minimum key should be constructed at the cut/fill
contact. A typical fill-over-cut detail is
presented in the Standard Guidelines for Grading
Projects which accompany this report as Appendix E,
4. Stabilization/Buttress Fills
Blanket stabilization fills are recommended for
cut and fill slopes over 10 feet in height con-
structed of Point Loma Formation and of Santiago
Formation siltstones and claystones where
laying-back the slopes to 2.5:1 is not adopted.
It should be noted that the wide stabilization
fills recommended to mitigate seepage on unsuit-
able geologic conditions will also receive the
equipment width cap of select material to min-
imize future surficial stability problems.
Anticipated buttresses and stabilization fills
are indicated on the attached Figure 4.
Approximate scale 1* : 325"
Anticipated areas of buttressing
and stabilization
ANTICIPATED LOCATION OF BUTTRESS AND STABILIZATION FILLS
JOB NO.:1163-00 DATE:AUGUST 1982 FIGURE:
SAN DIEGO SOILS ENGINEERING. INC.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Twenty-Five
5. Construction Slopes
Construction slopes in the Point Loma Formation
and Santiago Formation are recommended at slope
ratios of 1.5:1 to heights up to 30 feet. Above
that height, construction slopes are recommended
at slope ratios of 2:1 (horizontal:vertical).
These recommended ratios can be steepened if the
possibility of construction sliding is acceptable.
6. Natural Slopes
The proposed grading virtually eliminates natural
slopes adjacent to College Boulevard and "D"
Street.
C. Treatment of Alluvium
Alluvium is present in the canyon bottom areas on-site
and will require remedial treatment prior to fill
placement. In the canyons along College Boulevard
and "D" Street south of Carlsbad Research Center and
in the tributaries of Letterbox Canyon along the
northern extension of College Boulevard, it is recom-
mended that loose, porous or saturated alluvium be
removed to firm ground prior to fill placement. For
budgeting purposes, it should be considered that all
alluvium will be removed to bedrock.
Alluvium was observed to depths of about 25 feet in
the major northern thread of Letterbox Canyon. If
a delay between the completion of grading and future
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Twenty-Six
construction is acceptable, surcharging is an
acceptable alternative to alluvial removal in this
area. Our analysis indicates that a surcharge of
about 15 feet would result in about six months of
delay after grading before construction of buildings
could proceed.
The surcharge operation will require fill placement
to an elevation of 15 feet above proposed finished
grade. The surcharge fill should be compacted to
two (2) feet above proposed finish grade and then
placed as stockpile. Settlement markers should be
installed for monitoring after grading.
Our preliminary calculations indicate that enough
consolidation should occur within six months of
the end of grading to allow construction to proceed
in the surcharge area. Final determination of the
settlement period will, of course, be determined by
analysis of the settlement.
The limits of anticipated alluvial removals and area
of proposed surcharging are indicated on the attached
Figure 5.
D. Grading and Earthwork
1. Inspection
Continuous inspection by a geotechnical team
(Soil Engineer and Engineering Geologist) during
grading is essential to confirm conditions
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
NoSm
Approximate scale 1" : 325'
o
Proposed surcharge area
Anticipated areas of alluvial removals
AREAS OF ANTICIPATED ALLUVIUM AND RECOMMENDED TREATMENT
JOB NO.:1163-00 DATE:AUGUST 1982 FIGURE:
SAN DIEGO SOILS ENGINEERING. INC.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Twenty-Seven
anticipated by the preliminary investigation
and to provide data to adjust designs to actual
conditions encountered during grading.
2. Clearing and Grubbing
Prior to grading, the site should be cleared
of surface obstructions and stripped of brush
and vegetation. Vegetation from the clearing
operations should be removed from the site. Ob-
structions extending below finish grade should
be removed and replaced with compacted fill.
3. Site Preparation
a. Treatment of Surface Soils
Test excavations indicate that three to
four feet of surficial soils are present
on-site. The upper portions of the surface
soils are generally dry and porous.
It is recommended that in fill areas flatter
than 5:1 (horizontal:vertical) the
upper two feet of surface soils be over-
excavated in areas to receive fill. In
areas steeper than 5:1 (horizontal:
vertical) all topsoil will be removed during
the benching operation. Final determination
of removal depths will be made by the Geo-
technial Consultant during grading.
b. Existing Fill Soils
It is recommended that all areas of uncon-
trolled fill be overexcavated in areas to
receive fill.
Carlsbad Research Center Job No: SD1163-00
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Page Twenty-Eight
c. Treatment of Alluvium
It is recommended that alluvium be removed
or surcharged in accordance with the afore-
mentioned recommendations.
d. Scarification and Processing of Surface
Soils
Following overexcavation of unsuitable
materials, areas to receive fill and/or
other improvements should be scarified to
a depth of 6 to 8-inches, brought to near
optimum moisture conditions and compacted
to at least ninety percent relative com-
paction.
4. Compaction and Method of Filling
Fill placed at the site should be compacted to
a minimum relative compaction of 90 percent,
based on ASTM Laboratory Test Designation D 1557-70.
Fill should be compacted by mechanical means in
uniform lifts of 6 to 8-inches in thickness.
Fills constructed on natural slopes steeper than
5:1 (horizontal:vertical) should be keyed and
benched into bedrock or competent natural ground.
Compaction of slopes should be achieved by
overbuilding the slopes laterally and then
cutting back to the compacted core at design
line and grade. Although overbuilding and
cutting back is the preferred method, fill slopes
may be back rolled at intervals not greater than
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Twenty-Nine
four feet as the fill is placed, followed by
final compaction of the entire slopes. Feathering
of fill over the tops of slopes should not be
permitted.
Fills should also be placed and all grading per-
formed in accordance with the City of Carlsbad's
Grading Ordinance and the requirements of the
Uniform Building Code.
5. Selective Grading
As an alternative to laying-back slopes to a
ratio of 2.5:1, slope faces may be constructed
with select materials at a ratio of 2:1. Select
materials should consist of generally well-graded
granular materials with minor silt and clay
fractions. Select materials should be nonexpansive,
Suitability of proposed select material sources
should be determined upon evaluation of the
engineering properties of the materials. Some
select material is located off-site along the
alignment of "D" Street. The material consists
of a silty fine sand generated from the Quaternary
Terrace deposits.
In facing slopes with select material, it is
recommended that a width of not less than 10 feet
be maintained. Unless the minimum width is
increased to provide working area for conventional
slope compaction equipment, it is recommended
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Thirty
that the slopes be overfilled and cut-back to
the compacted inner core. If the source of
silty fine sand to the south is utilized for
facing of slopes, overfilling and cutting-back
is strongly recommended.
From discussions with the Project Civil Engineer,
it is our understanding that some slopes will be
laid back to 2.5:1 in lieu of utilizing select
material. A few slopes in more favorable material
types in the southern portion of the project are
not anticipated to be affected by the selective
grading recommendations. Also, the selective
grading recommendations should not be considered
applicable to slopes of ten feet in height or less.
Slopes presently anticipated to be affected by
this selective grading recommendations have been
indicated on the accompanying Figure 3.
Due to the undesirable engineering properties of
topsoil and alluvial soils, placement on the
interior of fill masses is recommended rather
than placement near slope faces.
6. Import Fill Material
Presently it is anticipated that import fill
materials may be required for selective grading
operations. The type of material considered
most desirable for import is a nonexpansive well-
graded granular material with minor silt and
clay fractions. The Geotechnical Consultant
Carlsbad Research Center Job No: SD1163-00
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Page Thirty-One
should be contacted for evaluation of individual
import sources well in advance of planned import
operations.
7. Shrinkage, Bulking and Subsidence
Volumetric shrinkage for the topsoil is estimated
to be from 15 to 20 percent. Shrinkage in the
alluvium is estimated to be from 10 to 15 per-
cent. Bulking in the Point Loma Formation
materials is expected to be from 5 to 10 percent.
Bulking in the Santiago Peak Volcanics is esti-
mated to be from 15 to 20 percent. Santiago
Formation bedrock is expected to bulk from 0 to
5 percent.
Because alluvium and porous topsoil are being
removed in most of the canyon areas, subsidence
there due to equipment will be negligible. Sub-
sidence will occur in the surcharge area, and
adjustments will be made during future grading.
Due to the fact that shrinkage and subsidence
can vary with many factors, it is recommended
that the above values only be used for preliminary
planning purposes. To provide for unforeseen
variations in actual quantities a "balance area"
should be designated by the Project Civil Engineer.
8. Transition Lots
Several building pads in Phase IV will be par-
tially graded in conjunction with the northern
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August 31, 1982 Log No: SD2-2484
Page Thirty-Two
extension of College Boulevard. Because the
grading will not reach finish grade elevations
at this time, and because the pads are large
industrial and commercial sites with building
locations as yet undetermined, no overexcavation
of transition lots is required. Overexcavation
to eliminate the cut/fill transition may be a
future recommendation when building location
and foundation designs are known.
E. Restriction on Future Construction
An eight (8)-inch diameter, high pressure petroleum
line located along El Camino Real may create a
restriction on future construction on a portion of
Carlsbad Research Center, Phase IV. The petroleum
pipeline is located in fill placed during the con-
struction of El Camino Real. Typically, recommendations
for placing fill adjacent to off-site road fills
include heavy benching into the road fills, which
sometimes results in minor disturbance to the pave-
ment surface. Discussion with the pipeline company
indicates that the high pressure pipeline will not
tolerate any disturbance. Due to the generally non-
uniform condition of the existing roadway fill, any
grading in the immediate area of the pipeline will
cause some disturbance. It is our opinon that the
only practical way to avoid disturbance at the pipe-
line is to minimize or avoid grading near the
petroleum pipeline.
More detailed analysis of this condition is recommended
when grading plans are finalized. The additional
Carlsbad Research Center Job No: SD1163-00
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Page Thirty-Three
analysis should help determine the solution which
will least impact the future building pad areas. No
other significant geotechnical restrictions are
anticipated on future construction if grading is
performed in accordance with the recommendations
presented herein. These recommendations will not,
however, preclude set-backs from buried utilities,
easements, etc.
F. Surface and Subsurface Drainage
Surface run-off into downslope natural areas and
graded areas should be minimized. Where possible,
drainage should be directed to suitable disposal
areas via non-erodible devices (e.g. paved swales
and storm drains).
Subdrains should be placed under all fills placed in
drainage courses and at identified or potential seep-
age areas. Their specific locations will be deter-
mined in the field during grading. General subdrain
locations will be indicated on the approved grading
plan. The subdrain installation should be reviewed
by the Engineering Geologist prior to fill placement.
Typical subdrain details are presented in Apprendix
E, Standard Guidelines for Grading Projects. Sub-
drain pipe may be coated metal, P.V.C., or approved
equivalent (crush strength of 1000 pounds/foot or
greater).
Drainage devices will be recommended behind buttresses
and/or stabilization fills to minimize the build-up
Carlsbad Research Center Job No: SD1163-00
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Page Thirty-Four
of hydrostatic and/or seepage forces. The details
and recommended locations of these back drains are
presented in Appendix E, Standard Guidelines for
Grading Projects. Depending on slope height, more
than one tier of drains may be required. Drains may
also be recommended at contacts between permeable
and nonpermeable formations.
G. Retaining Walls
The development of geotechnical design criteria for
retaining walls can be best developed following
review of the proposed wall configurations and review
of the site specific geotechnical conditions. Over
most of the site, however, the following criteria
may be utilized for preliminary design purposes.
Where free-standing walls are proposed to retain
granular backfill, equivalent fluid weight for static
active lateral earth loadings of 45, 70 and 90
pounds per cubic foot may be utilized for walls
retaining level, 2.5:1 and 2:1 backfill conditions
respectively. Appropriate allowances should be made
for anticipated surcharge conditions, unless walls
are also designed to resist seepage and/or hydro-
static forces. Walls should be provided with designed
drainage systems.
It should be noted that the use of heavy compaction
equipment in close proximity to retaining walls can
result in excess wall movement (strains greater than
those normally associated with the development of
active conditions) and/or soil pressures exceeding
Carlsbad Research Center Job No: SD1163-00
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Page Thirty-Five
design values. In this regard, care should be taken
during back-filling operations.
H. Type of Cement for Construction
Evaluation of soluable sulfate content of samples
considered representative of the predominate material
types on site suggest that Type V concrete is not
a requirement for use in construction. Type I or II
cement should be utilized. Cement type recommendations
should be verified following site specific investi-
gations on individual streets.
I. Pavements
Due to generally poor subgrade characteristics of
the predominant soil types, generally heavy pavement
sections can be anticipated. For traffic index
values of 7.0, 8.0 and 8.5 which are expected for the
street areas, the following preliminary pavement
sections can be utilized for planning purposes.
Traffic Index 7.0 8.0 8.5
R-Value 7.0 7.0 7.0
Pavement Thickness 4" 4" 5"
Aggregate Base 15" 18" 19"
Total Thickness 19" 22" 24"
From review of the above sections, it is apparent that
street areas during rough grading should be kept about
two feet low to accomodate the pavement sections.
Pavement recommendations should be reviewed as final
grades are achieved.
Carlsbad Research Center Job No: SD1163-00
August 31, 1982 Log No: SD2-2484
Page Thirty-Six
If practical, selective grading in street areas may be
considered for the purpose of reducing pavement
section requirements. If it is considered practical to
place about one-foot of good granular material in
street subgrade areas, the required aggregate base
material section could be reduced substantially.
J. Utility Trench Backfill
Utility trench backfill should, unless otherwise
recommended, be compacted by mechanical means. Unless
otherwise recommended, the degree of compaction should
be a minimum of 90% of the laboratory maximum density.
As an alternative, granular material (Sand Equivalent
greater than 30) may be thoroughly jetted in-place.
Jetting should only be considered to apply to trenches
no greater than two-feet in width and four-feet in
depth. Following jetting operations, trench backfill
should be thoroughly mechanically compacted and/or
wheel rolled from the surface.
K. Grading Plan Review
When final grading plans for the proposed development
are completed, the plans should be reviewed by the
Geotechnical Consultant to determine compliance with
the recommendations presented herein. Substantial
changes from the present plan may necessitate additional
investigation and analyses.
Carlsbad Research Center Job No: SD1163-00
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Page Thirty-Seven
L. Limitations of Investigation
Our investigation was performed using the degree of
care and skill ordinarily exercised, under similar
circumstances, by reputable Soils Engineers and Geo-
logists practicing in this or similar localities. No
other warranty, express or implied, is made as to the
conclusions and professional advice included in this
report.
The samples taken and used for testing and the obser-
vations made are believed representative of the entire
area. However, soil and geologic conditions can
vary significantly between borings, test pits and
surface outcrops.
As in most major grading projects, conditions revealed
by excavation may be at variance with preliminary
findings. If this occurs, the changed conditions must
be evaluated by the Geotechnical Consultant and designs
adjusted or alternate designs recommended.
Very truly yours,
SAN DIBGO SOILS ENGINEERING, INC.
n, R.C.E. 26098 Stephen W. \JTensen, C.E.G. 1074
Chielf Eng-inesr Manager, Geologic Services
GWA:SWJ:tm
APPENDIX A
REFERENCES
1. "Eocene and Related Geology of a Portion of the San Luis
Rey and Encinitas Quadrangles, San Diego County," December
1972: University of California, Revierside, Masters
Thesis prepared by K. L. Wilson;
2. Mines and Mineral Resources of San Diego County, 1963:
California Division of Mines and Geology, County Report 3;
3. Crustal Strain and Fault Movement Investigation, January
1964: California Department of Water Resources Bulletin
No. 116-2;
4. "Accelerations in Rocks for Earthquakes in the Western
United Stages," Bulletin of the Seismological Society of
America, Vol. 63, No. 2, Schnabel and Seed, April 1973;
5. Fault Hazard Zones in California, Revised January 1977:
California Division of Mines and Geology, Special Publi-
cation 42;
6. "Fault Map of California," 1975: California Division of
Mines and Geology, Geologic Data Map No. 1;
7. "Repeatable High Ground Accelerations from Earthquakes,"
California Geology, California Division of Mines and
Geology, Ploessel and Slosson, September 1974;
8. Clay Mineralogy and Slope Stability, Special Report 133,
California Division of Mines and Geology, 1977;
9. Seismicity of the Southern California Region 1932-1972,
1973;California Institute of Technology, Seismological
Laboratory;
10. "Preliminary Soil and Geologic Investigation, Carlsbad
Research Center, Carlsbad,California" April 1981, Woodward-
Clyde Consultants;
11. "Additional Studies, Carlsbad Research Center, Carlsbad,
California" August 1981, Woodward-Clyde Consultants;
12. "Addendum to Additional Studies, Carlbad Research Center,
Carlsbad, California" September 1981, Woodward-Clyde
Consultants;
13. "Aerial Photographs," USDA Flight AXN-8M, 1953, Photo
Nos. 71-73, 99-101.
APPENDIX B
SUBSURFACE EXPLORATION
The subsurface exploration consisted of 10 borings to a maximum
depth of 70 feet, 35 backhoe test pits excavated to a maximum
depth of 15 feet and three bulldozer trenches excavated to a
maximum depth of 6 feet and maximum length of 240 feet. The
borings were drilled with a truck-mounted bucket auger drill
rig, the test pits were excavated with a tractor-mounted back-
hoe and the dozer trenches were excavated with a D-8 bulldozer.
The subsurface exploration was conducted under the direction of
the Engineering Geologist. The borings and pits were logged,
sampled and backfilled. Samples of the materials encountered
were returned to the laboratory for testing.
Logs of our borings are presented as Figures B-2 through B-19.
The logs of test pits are presented as Figures B-20 through
B-55. The logs of the three dozer trenches are presented as
Figures B-56 through B-59. The locations of the borings,
pits and trenches included in this appendix are shown on the
attached Geotechnical Maps, Plates 1 and 2.
California Sampler blow counts were obtained by driving a 2.625
inch, inside diameter sampler with a hammer dropping through a
12-inch free fall. A 1600 pound hammer was used at depths less
than 25 feet and an 800 pound hammer was used at depths greater
than 25 feet. Unless otherwise shown, the blows per foot
recorded on the Boring Logs represent the number of blows used
to drive the sampler 12 inches. Samples shown on the Boring
Logs as "UNDISTURBED SAMPLES" were obtained with the California
Sampler.
PRIMARY DIVISIONS GROUP
SYMBOL SECONDARY DIVISIONS
GRAVELS
MORE THAN HALF
OF COARSE
FRACTION IS
LARGER THAN
NO 4 SIEVE
SANDS
MORE THAN HALF
Of COARSE
FRACTION IS
SMALLER THAN
NO 4 SIEVE
CLEAN
GRAVELS
(LESS 1HAN
5N, FINES)
GW Well graded gravels gravel-sand nu>:uie-.. lit tie or no
tines
GP Poorly graded gravels or gravel-sand matures little or
no fines
GRAVEL
WITH
FINES
GM Silly gravels, gravel-sand-silt mixtures non-plastic fines
GC Clayey gravels, gravel-sand-clay mixtures, plastic lines
CLEAN
SANDS
(LESS THAN
5% FINES)
SW Well graded sands, gravelly sands little or no lines
SP Poorly graded sands or gravelly sands, little or no fire*
SANDS
WITH
FINES
SM Silly sands, sand-silt mixtures, non-plait* fines.
SC Clayey sands, sand-clay mixtures, plastic firm.
&§ «SILTS AND CLAYS
LIQUID LIMIT IS
LESS THAN 50%
Inorganic silts and very fine sands, rock flour, si'ty orclayey fine sands or clayey silts with slight plast*ity.
CL Inorganic clays of low to medium plasticity, gravellyclays, sandy clays, silly clays, lean clays
OL Organic silts and organic silty clays of low plasticity
SILTS AND CLAYS
LIQUID LIMIT IS
GREATER THAN 50%
MH Inorganic silts micaceous or diaiomaceou* fine sandy orsilly soils, elastic silts
CH Inorganic clays of high plasticity, fat clays.
OH Organic clays of medium to high plasticity, organic silts.
HIGHLY ORGANIC SOILS Pt Peat and Other highly organic soils
200
DEFINITION OF TERMS
U.S. STANDARD SERIES SIEVE
40 10
CLEAR SQUARE SIEVE OPENINGS
3/»" 3" 12"
SILTS AND CLAYS
SAND
FINE MEDIUM COARSE
GRAVEL
FINE COARSE
COBBLES BOULDERS
GRAIN SIZES
VERY LOOSE
LOOSE
MEDIUM DENSE
DENSE
VERY DENSE
0-4
4 -tO
tO -30
30-50
OVER SO
VERY SOFT
SOFT
FIRM
STIFF
VERY STIFF
HARD
0 - 1/4
\A — 1/5
V2 - 1
1 - 2
2-4
OVER 4
0-2
2-4
4-8
8 -16
16-32
OVER 32
RELATIVE DENSITY CONSISTENCY
Number of blows of 140 pound hammer falling 30 inches to drive • 2 inch O D (1-3/8 men ID.)
split spoon (ASTM 0-1586).
tUnconfmed compressive strength in tons/sq. ft as determined by laboratory testing or approximated
by the standard penetration lest (ASTM D-1586). pocket penetrometer. torvane. or visual observation.
KEY TO EXPLORATORY BORINQ LOGS
Unified Soil Classification System (ASTM D-2487)
J°B Na: SD1163-00 °ATE: August 1982 FIGURE:B-l
SAN DIEGO SOILS ENGINEERING. INC.
DATE OBSERVED-. 4-12-82 METHOD OF DRILLING- 24" Bucket Auger
LOGGED BY: KS GROUND ELEVATION- 252' - LOCATION: See MaP
Ul
Ul
1^
x
a.Ula
-
6-
"
1Q
16-
20-
25-
30-
35-
40-
z
!Z
COco<
o
Hoou.
CO*o
CD
3
q
8
0Ul
DUJCC_|
3CL
S3a coz
x
x
x
Ul
a.
CO
CO
x
x
s£
co|
Oz20u
24
??
18
>-C
^^
1«o-z
SQ
97
ins
109
RORIMtt NO 1
DESCRIPTION
TOPSOIL: Brown CLAY, Moist to
Wet, Firm
BEDROCK: POINT LOMA FORMATION;
Green Gray Clayey SILTSTONE,
Moist, Stiff to Very Stiff, with
Orange Staining, Fractured and
Weathered to 5 ' Jointed
@7'-10' Joints with Minor Slicks
N35°W, 35°NE; N54°E, 75°SE;
E-W, 62°S; N10°E, 80°E;
N5°W, 90°; N70°E, 35 N
@13' Joints, N-S, 65 E; N40°E,
18 NW
@14' Less Jointed, More Massive
@17' Cemented Layer, 2" Thick,
Horizontal
@18' Joint, N80°E, 62°N
@20' Cemented Layer, 8" Thick
Siltstone Fractured above
20', More Massive Below
@20'-31' Seepage of Ground Water
§26 '-30' Increasing Seepage in
Joints
§29' Joints, N20°E, 42°W; N20°E,
5°W
Black Grey Clayey SILTSTONE,
Moist, Very Stiff to Hard,
Massive
SOIL TEST
DIRECT SHEAR
ATTERBERG LIMIT!
EXPANSION TEST
DIRECT SHEAR
JOBNO.: SD1163_00 LOG OF BORING FIGURE: B-2
SAN DIEGO SOILS ENGINEERING. INC.
DATE OBSERV
LOGGED BY:.I DEPTH (FEET)+9
56-
60-
65-
70-
75-
80-1 CLASSIFICATION]BLOWS/FOOT!,pn- 4-12-82 METHOD OF DRILLING: 24" Bucket Auaer
KS GROUND ELEVATION: 252' - LOCATION- See Map
UNDISTURBED 1SAMPLE |BULK SAMPLE IX
X
JOBNO.:SD1163_00 MOISTURECONTENT (%)IN PLACE DRYDENSITY (PCF)RORINCS NO 1
(CONTINUED)
DESCRIPTION
Total Depth 50'
Water at 20 '-31'
No Caving
SOIL TEST
LOG OF BORING FIGURE: B 3
c»u nicnrt <5nn <s PNOINPFRING. INC.
DATE OBSERV
LOGGED BY:_' DEPTH (FEET)6-
4A_
16-
4U
25-
36-
*V CLASSIFICATION!•MHMH BLOWS/FOOT |3
11
8
15
ED- 4-13-82 METHOD OF DRILLING- 24" Bucket Auaer
-i-
KS GROUND ELEVATION! 234 ' ~ LOCATION: See Map
UNDISTURBED 1SAMPLE |X
X
X
X BULK SAMPLE 1X
X MOISTURE . 1CONTENT (%)12
9
16
18 IN PLACE DRY 1DENSITY (PCF)112
124
112
RORING NO 2
DESCRIPTION
TOPSOIL: Brown CLAY, Moist to
Wet, Soft with Organics.
BEDROCK: SANTIAGO FORMATION:
White Grey Sandy CLAYSTONE/Claye
SANDSTONE, Moist, Very Stiff,
Massive, with Reddish Staining.
Light Green CLAYSTONE, Moist,
Stiff, Red Staining, Jointed and
Slightly Fractured.
@18' Joint N63°E, 90°
@ 25' Green Remolded CLAY Seam,
1" Thick, N30 E, 15° W,
Wet and Soft.
POINT LOMA FORMATION: Green Gre?
Clayey SILTSTONE, Moist, Very
Stiff, Jointed
@ 28' Joints N30 W. 40 N; E-W,
85 S, E-W, 68 N.
@ 29' Cemented Layer, 6" Thick
@ 32' Joint N70 E, 62 S
@ 34' Less Jointing More Massive,
Gypsum Seams
SOIL TEST
ATTERBERG LIMITS
CXPANSION TEST
5IEVE ANALYSIS
IYDROMETER TEST
1AXIMUM DENSITY
:ONSOLIDATION
DIRECT SHEAR
(Remolded)
JOBNO.:SD1163_00 LOG OF BORING FIGURE: B- 4
SAN DIFQO SOILS ENGINEERING. INC.
DATE nuRPBwei* 4-13-82 METHOD OF DRILLING- 24" Bucket Aucrer
LOGGED BY- KS GROUND ELEVATION- 234 ' - LOCATION- See Map
i DEPTH (FEET)-
46-
-
56-
60-
65-
70-
80-CLASSIFICATION!BLOWS/FOOT]15 UNDISTURBED 1SAMPLE |x BULK SAMPLEX
X
JOBNOJ SD1163-0 MOISTURECONTENT (%)15 IN PLACE DRY 1DENSITY (PCF) 1106
RORINR NO 2
(CONTINUED)
DESCRIPTION
Black Grey Clayey SILTSTONE,
Moist, Very Stiff Massive
@ 42' Joints with Gypsum N8° E,
45 E; N15° W, 56 E
@ 45' Cemented Layer, 3" Thick
Horizontal
Total Depth 51'
No Water
No Caving
SOIL TEST
0 LOG OF BORING FIQUR*. B_5
Q»U nicnrt cnu <5 INC
HATF OHRERVED- 4-14-82 METHOD OF DRILLING: 24" Bucket AUQSr
LOGGED BY: KS GROUND El EVATION- 308' - LOCATION-. See Map
P
UlUlu.
X
0.Ul0
5-
-
_
-
10
15-
20-
25—
30-
35-
4O
o
5o
ttoo>
.jo
Koou.
0)a»$
O_»
0
18
12
9
15
oUlDUItt «j
-2
SCOz
3
X
x
X
x
Ul
0.
n
3m
x
><^
^
UJ*
3»Ssllo
10
7
13
9
>C
5°OQ.
Ul**3E
s!S2^J
109
110
L13
IOS
BORING NO 3
DESCRIPTION
TOPSOIL: Light Brown Clayey
VSAND, Dry, Loose
BEDROCK: SANTIAGO FORMATION:
Light Yellow-Green Fine-Medium
SANDSTONE, Moist, Medium Dense
with Orange Staining.
@6.5' Green Clay Seam, 1/4" Thicl
Horizontal, Not Continuous
@10' Cross Bedding Approximately
Horizontal
@21' Clayey Layer, 2" Thick,
Undulates
324' Clayey Layer, 8" Thick,
Undulates
Light Green CLAYSTONE, Moist,
Very Stiff, Massive
SOIL TEST
EXPANSION TEST
SIEVE ANALYSIS
DIRECT SHEAR
DIRECT SHEAR
MAXIMUM DENSITY
CONSOLIDATION
DIRECT SHEAR
(Remolded)
DIRECT SHEAR
DIRECT SHEAR
JOBNO.:SD1163-00 LOG OF BORING FIQURE:B-6
SAN DIEQO SOILS ENGINEERING. INC.
DATE OBSERV
LOGGED BY:_» DEPTH (FEET)45-
IE ft
60-
65-
70-
75-
80-CLASSIFICATION!BLOWS/FOOT 116
16
en- 4-14-82 MPTHOO OF DRILLING- 24" Bucket Auqer
KS GROUND ELEVATION: 308'- LOCATION- See Map
UNDISTURBED 1SAMPLE 1x
X BULK SAMPLE 1X MOISTURE 1CONTENT (%)13
8
>C£0Qo.
ui~St*2*%
110
109
FtnRINfi NO 3
(CONTINUED)
DESCRIPTION
@42' Green CLAYSTONE Layer,
1' Thick, Approximately
Horizontal, Massive
@43.5' Bedding N-S, 8°W
@44' Green CLAYSTONE Layer, 1'
Thick, Massive, N-S, 8°W
Total Depth 55'
No Water
No Caving
SOIL TEST
JOBNO.SDH63-00 LOG OF BORING FIGURE.- B_7
e*u nicnrt orui «INC.
HATP OBSERVED- 4-15-82 METHOD OP nHiitiNfl- 2 4 " Bucket Auger
-i-
LOGGED BY- RS GROUND ELEVATION- 182< ~ LOCATION- Offslte
> DEPTH (FEET)6-
10-
20-
OK—
30-
40-CLASSIFICATION!BLOWS/FOOT I15
8
L6 UNDISTURBED 1SAMPLE 1H
X
X BULK SAMPLE 1X MOISTURE ICONTENT (%)11
12
18 IN PLACE DRY IDENSITY (PCF) |110
111
110
BORING NO.__1_
DESCRIPTION
BEDROCK: SANTIAGO FORMATION;
White-Light Green Silty, Fine
SANDSTONE, Moist, Medium Dense
Massive, with Red Staining
@ 8 '-9' Light Green Silty CLAY-
STONE, Moist, Very Stiff
@13'-14' Light Green Clayey SILT-
STONE, Moist, Hard
323' Green Clay Seam, 1/2" Thick,
Horizontal
@27' Horizontal Bedding
928 '-30' Green Brown Silty CLAY-
STONE
jight Green Silty CLAYSTONE, with
fine Sand Lenses, Moist, Very
Stiff, Occasional Fractures with
Small Slicks, Massive
SOIL TEST
JOBNO.:SD1163_00 LOG OF BORING FIGURE: B_8
SAN DIEGO SOILS ENGINEERING. INC.
DATE OBSERV
LOGGED BY:_) DEPTH (FEET)46-
Rf\
66-
76-
80-CLASSIFICATION!BLOWS/FOOT |15
16
pn- 4-15-82 METHOD OP DRILLING- 24" Bucket Auaer
KS GROUND ELEVATION: 182' - LOCATION- Offsite
UNDISTURBED 1SAMPLE 1X
X BULK SAMPLE IX
JOBNO.: SD1163-0 MOISTURECONTENT (%)10
10
>Cocooo.
Ul~
St
5!z
£g
109
L19
RORINtt NO 4
(CONTINUED)
DESCRIPTION
Light Green Medium SANDSTONE,
Moist, Medium Dense, Massive
@53'&55' Cemented Zones, 6* Thick
Horizontal, with Gypsum Seams
Blue Grey Silty Fine-Medium SAND-
STONE, Moist, Medium Dense,
Passive
Total Depth 70'
No Water
No Caving
SOIL TEST
0 LOG OF BORING f\Qu*t: B-9
«nii
DATE OBSERV
LOGGED BY:.> DEPTH (FEET)-
16-
26-
Qft_
38-
40-CLASSIFICATION!BLOWS/FOOT |6
5
14
16
,fn. 4-16-82 METHOD OP DRILLING- 24" Bucket Auger
i.
RG OPOUNO ELEVATION- 180' ~ LOCATION- See Map
UNDISTURBED 1SAMPLE |X
X
X
X BULK SAMPLE 1X MOISTURE 1CONTENT (%)18
27
12
12
>CSE«OO.
"CStiS
SS
106
95
120
105
RORING NO 5
DESCRIPTION
BEDROCK: SANTIAGO FORMATION;
White to Light Yellow SANDSTONE,
Mottled, Moist, Medium Dense
Grey SILTSTONE, Moist, Soft,
Fractured
Dark Reddish Brown CLAYSTONE,
Moist to Wet, Firm to Stiff,
Fractured, with slight Seepage
k in Fractures
POINT LOMA FORMATION; Green-
Yellow Gray SILTSTONE, Moist to
Wet, Stiff, Massive @ 13' Contact
yN69 E, 5°SE
Gray CLAYSTONE, Moist to Wet,
Stiff, Fractured with Seepage in
Fractures, Gypsum Seams
@22' Color grades to Purple and
Grey, Seepage Confined to
North Side of Hole
@30' Seepage Ends
1338' Grey Sandy SILTSTONE, Joint,
N65°W, 24°NE
SOIL TEST
DIRECT SHEAR
JOBNO.:SD1163_00 LOG OF BORING JFIGURE: B-10
SAN DIFOO SOILS ENGINEERING. INC.
OATP OBSEBVPO- 4~lb-«2 METHOD OF DRILLING- 2 4 " Bucket Auqer
LOGGED BY: RG GROUND EL
DEPTH (FEET)-
45-
-
-
RO-
SS-
.0,
66-
70-
76-
80-LASSIFICATION!u BLOWS/FOOT 118
.
14 UNDISTURBED 1SAMPLE |XI
X
X BULK SAMPLE 1X MOISTURECONTENT (*)17
14
14
>CSoOQ.
Sis109°-z
SB
in
102
107
EVATION: ! 8 ° ' ~ LOCATION: See Map
RORINfi NO 5
(CONTINUED)
DESCRIPTION
Dark Grey to Black SILTSTONE,
foist, Hard, Massive.
:ontact E-W 4 N; Seepage at Con-
:act.
Foint N20 W, 90°
Total Depth 58'
Seepage at 10I-30'&431
No Caving
SOIL TEST
DIRECT SHEAR
JOB NO.:SD1163-00 LOG OF BORING FIGURE: B-ll
HATE OBRPHvPn- 4-16-82 MPTHOH OP DRILLING- 24" Bucket Auger
LOGGED BY- KS GROUND ELEVATION: 16 ° ' ~ LOCATION- See Map
DEPTH (FEET)8
—
W
_
15-
25-
36-
40-
2
LASSIFICATIOv BLOWS/FOOT7
10
L6
23 UNDISTURBEDSAMPLEX
X
X
X BULK SAMPLEJOB NO^ SD1163-0 MOISTURECONTENT (%)19
18
18
18
°t
106
10
1 11
105
RORINR NO 6
DESCRIPTION
BEDROCK: POINT LOMA FORMATION;
Green Grey Clayey SILTSTONE,
Moist, Stiff to Very Stiff, with
Orange Staining, Slightly
Fractured
@7' Joint N15°E, 58°E
68' Joint N22°W, 58°NE
@10' Gypsum Seam N70°E, 65°W
@13' Gypsum Seam V Thick
Horizontal
@17' More Massive, Very Stiff
@23'-26' Many Gyosum Seams 1/8"
to 1/2"
>
SOIL TEST
SIEVE ANALYSES
HYDROMETER TEST
ATTERBERG LIMITS
DIRECT SHEAR
3 LOG OF BORING ftou** B_12
nipnn smi A PNntNPPRiNO INC
DATE OBSERVED:4-16-82 MPTHOO OF DRILLING- 24" Bucket Auger
LOGGED BY- KS GROUND ELEVATION: 160' - LOCATION: See Map
> DEPTH (FEET)45-
50-
55-
60-
65-
70-
76-
80-CLASSIFICATION!BLOWS/FOOT I23 UNDISTURBED 1SAMPLE 1X BULK SAMPLEMOISTURECONTENT (%)18 IN PLACE DRYDENSITY (PCF)109
BORING NO 6
(CONTINUED)
DESCRIPTION
@43'-47' Seepage in Joints to
Contact @ 47'
Grey Black SILTSTONE, Moist,
Hard, Massive
Total Depth 51'
Seepage at 43 '-47'
No Caving
SOIL TEST
DIRECT SHEAR
jOBNO.:SDn63_oo LOG OF BORING FIGURE: B-13
DATE OBSERV
LOGGED BY:_' DEPTH (FEET)4A—
1R—
onZU
25-
4fl
35-
40-CLASSIFICATION!CL BLOWS/FOOT I2
5
5
4
6
18
Pn. 6-7-82 METHOD OP DB.LL.MG- 2 4 " Bucket Auger
KS GROUND ELI
UNDISTURBED 1SAMPLE |X
X
x
X
X
X BULK SAMPLE 1X
x
X
JOB NO.: SD1163-0 MOISTURECONTENT (%)20
20
21
21
19
20 IN PLACE DRY 1DENSITY (PCF) |100
106
103
104
105
L02
-4- _ , .
CATION- 104' - LOCATION. See Map
BORING NO 7
DESCRIPTION
ALLUVIUM: Dark Olive Brown
Silty CLAY, Moist, Soft
Reddish Brown Silty CLAY, Moist
Soft
BEDROCK: POINT LOMA FORMATION:
Dark Grey Sandy SILTSTONE, Mottle
tfith Red-Brown Staining, Moist,
Firm to Stiff, Fractured.
927' Less Weathered
@38' Cemented Layer
/" Total Depth 39.'
No WaterNo Caving
SOIL TEST
MAXIMUM DENSITY
CONSOLIDATION
SIEVE ANALYSIS
HYDROMETER
ATTERBERG LIMITS
1
0 LOG OF BORING FIGURE: B_i4
SAN DIEGO SOILS ENGINEERING. INC.
HATF ORRFRVFD- 6~7~82 METHOD OF DRiL i iN<v 24" Bucket Auger
LOGGED BY: KS GROUND ELEVATION: 106' - LOCATION- See Map
EPTH (FEET)o
-
10-
20—
25-
30-
35-
40-ASSIFICATION9
CL
V
^™LOWS/FOOTCD
5
3
20 NOISTURBED 1SAMPLE |3
"V -X^s
X
X ULK SAMPLEa
X
X MOISTUREONTENT (%)u
18
24
15
°&
5ill
Q
101
93
110
BORING NO._§
DESCRIPTION
ALLUVIUM: Brown Silty CLAY, Moist
Soft
:ontact Approximately N65°E,10°NE
jight Olive Brown Silty CLAY,
lottled, Moist, Soft
5EDROCK: POINT LOMA FORMATION;
Dark Grey-Black Silty SANDSTONE,
toist, Medium Dense to Dense,
tfith Orange Staining
323' Cemented Lens, 3" Thick,
Dense Below
?30' Seepage begins
@36' Water Standing in Hole
SOIL TEST
CONSOLIDATION
JOBNO^ SD1163-00 LOG OF BORING FIGURE: B_15
RAN DIFOO SOUS ENGINEERING. INC.
DATE OBSERVED:
LOGGED BY: KS
! DEPTH (FEET)45-
-
.
50-
56-
60-
65-1
70-
75-
80-CLASSIFICATION!BLOWS/FOOT 1UNDISTURBED 1SAMPLE 16-7-82 METHOD OP DRILLING- 2 4 " Bucket Auqer
GROUND EIPVATION- 106' - LOCATION: See Map
BULK SAMPLE 1MOISTURE 1CONTENT (%)IN PLACE DRY 1DENSITY (PCF) |RORINtt NO 8
(CONTINUED)
DESCRIPTION
Dark Grey Black Silty SANDSTONE
Moist, Medium Dense to Dense
Total Depth 43'
Water at 30'
No Caving
SOIL TEST
JOBNo^sDll63-oo LOG OF BORING FIGURE: B- 16
CAM mcrsn QDII ft PMniNFPRiNG INC
DATE OBSERV
LOGGED BY:.» DEPTH (FEET)-
1X
20-
30-
35-
40-CLASSIFICATION!BLOWS/FOOT |3
6
6
rpn. b-a-«2 METHOD OF nmi i INQ. 2 4 " Bucket Auger
KS GROUND ELEVATION: 125' - LOCATION; See Map
UNDISTURBED 1SAMPLE 1X
x
X BULK SAMPLE 1X
JOBNO-SD1163-00 MOISTURECONTENT (%)20
21
19 IN PLACE DRY 1DENSITY (PCF) |105
103
106
ROBING NO 9
DESCRIPTION
ALLUVIUM: Brown Silty CLAY,
Moist, Soft
BEDROCK: POINT LOMA FORMATION;
Dark Green Brown Clayey SILT-
STONE, Moist, Stiff to Very Stif:
Fractured
(§11' Less Weathered
@15' Wet
Dark Grey Black SILTSTONE,
Saturated, Very Stiff, Fractured
Total Depth 25'
Water at 22'
No Caving
SOIL TEST
LOG OF BORING F\<M**. B-17
SAN DIEGO SOILS ENGINEERING, INC.
DATE OBSERVED: 6-10-82 METHOD OF DRILLING- 24" Bucket AUQer
IOGQED BY: SWJ GROUND ELEVATION: 180 ' - LOCATION: See Geo technical Map
p
Ul
It
> DEPTH (1-
5-
-
10-
15-
20-
25-
30-
35-
*o
zo
t<CLASSIFKH
O
u_BLOWS/0UlflD ujKj
UNDISTUSAMPUl
a.2
CO
_j
3ID
u£
2E ^-MOISTICONTEN>cr
£0Oo.IN PLACEDENSITYRORINR NO 10
DESCRIPTION
3 Feet of Topsoil and 3 Feet of
Bedrock Removed. Boring Drilled
in Bulldozer Excavation
BEDROCK: SANTIAGO FORMATION;
Yellow Brown to Rust Medium SAND-
STONE
@9' Abrupt Color Change to Grey
White
09.51 Brown Oxidized Bed N50°W,
10 SW
@10' Brown SANDSTONE
@11.5' Sheared Grey SILTSTONE
With Staining
BEDROCK: POINT LOMA FORMATION;
Grey CLAYSTONE With Yellow
Staining, Firm to Medium Stiff,
Moist
014' Brown Sheared CLAY, N35°W,
75°SW
017' Sheared CLAYSTONE, N30 W,
60 SW
Seepage on North Side of Boring
@27' Shear Surface E-W, 22°S
@28' Shear Surface N80 E, 42 S
§31' Bedding E-W, 38°S
@33'-39' Vertical Joint, E-W
@38' Seepaae
/ Dark Grey SILTSTONE, Massive
' Stiff to Very Stiff
SOIL TEST
joBNo.:SD1163_00 LOG OF BORING FIGURE: B-l 8
SAN DIEQO SOILS ENGINEERING. INC.
DATE OBSERVED:
LOGGED BY: SWJ
) DEPTH (FEET)45-
50-
55-
60-
65-
70-
75-
80-CLASSIFICATION!BLOWS/FOOTUNDISTURBED 1SAMPLE |6-10-82 MPTHOO OP npiiLiNft- 24" Bucket Auaer
GROUND ELEVATION: 180' - LOCATION: See Gf?Ol-efThni O3 1 M^P
BULK SAMPLE 1MOISTURE 1CONTENT (%)>cs°OO.*z5t*sz%
ROPING NO 10
(CONTINUED)
DESCRIPTION
Dark Grey SILTSTONE, Massive,
Stiff to Very Stiff
Total Depth 48'
Seepage 17' - 38'
No Caving
SOIL TEST
JOBNO.:SD1163_00| LOG OF BORING FIGURE: B- 19
pATF OBSERVED- 4~28~82 METHOD OF DRILLING- 24" Backhoe
LOGGED BY! KS GROUND ELEVATION- 204' - LOCATION: See Map
> DEPTH <FEET)5-
15-
20-
26-
30-
36^
40-CLASSIFICATION!BLOWS/FOOT 1UNDISTURBED 1SAMPLE jBULK SAMPLEX MOISTURECONTENT (%)IN PLACE DRY jDENSITY (PCF)JTEST PIT NO. 1
DESCRIPTION
BEDROCK: SANTIAGO FORMATION;
Brown Mottled SILTSTONE, Moist
Firm, Fractured, with Yellow
Staining and Gypsum Seams %-%" .
@5' Joint: N80°E, 85°S
@6' Black Organic Seams (2), with
Shell Debris, NS, 4°W
@7' Massive, Less Fractured, Stii
V
Total Depth 9.5'
No Water
No Caving
SOIL TEST
JOBNOJ SD1163_00| LOG OF TEST PIT F|Q"R* B-20
RAN DIEGO SOILS ENGINEERING. INC.
RATE OBSERVED: 4-28-82 METHOD OF DRILLING: 24" Backhoe
LOGGED BY: KS GROUND ELEVATION: 2 26 ' - LOCATION: See Map
EPTH (FEET)0
-
10-
15-
20-
25-
30-
36-
40-ASSIFICATION!-iu LOWS/FOOT 1ffl NDISTURBED ISAMPLE 1a ULK SAMPLE 1a
Sx'X^v MOISTURE 1ONTENT (%)O
Oo.
Z 4r
H
TEST PIT NO. 2
DESCRIPTION
TOPSOIL: Light Brown CLAY, Wet,
\ Soft
BEDROCK: SANTIAGO FORMATION;
Light Green Grey, with Yellow
^Staining, Clayey Sandy SILTSTONE,
* Moist, Stiff, Massive with
\ Fractures, and Gypsum Seams
Light Green White Fine Sandy
\SILTSTONE, Moist, Stiff, Massive
Total Depth 7'
No Water
No Caving
SOIL TEST
JOBNO.:SD1163_00 LOQ op TESJ p,j FIGURE: B-21
RAN DIEGO SOILS ENGINEERING. INC.
DATE OBSERVED! 4-28-82 METHOD OF DRILLING! 24" Backhoe
LOGGED BY! KS GROUND ELEVATION! 168' - LOCATION! See Map
PUJUJu.
I
0.UJ0
6-
16-
20-
26-
30-
35-
40-
z
FICATIOCOCO<
O S/FOOT£O_iCD TURBEDMPLE2<am
3 SAMPLEX_i3CD
X
x
Ifco>>>rHOz20U
UJ**
s!i
— S
TEST PIT NO. 3
DESCRIPTION
TOPSOIL: Red-Brown Silty CLAY,
v Moist, Soft
BEDROCK: SANTIAGO FORMATION;
Light Green Silty CLAYSTONE,
Moist to Wet, Firm to Stiff
*v Weathered with Brown Mottling
Light Green Clayey SILTSTONE;
Moist, Stiff to Very Stiff
\
Brown SILTSTONE, Moist to Wet,
Firm with Yellow Staining,
V Horizontally Bedded.
Total Depth 11'
No Water
No Caving
SOIL TEST
JOBNO-SDH63-oo| LOG OF TEST PIT F|GURE: B-22
SAN son s ENGINEERING. INC.
DATE OBSERVED: 4-28-82 METHOD OF DRILLING! 24" BackhOG
i.nnoEDBY KS GROUND ELEVATION- 160 ' - LOCATION- See Map
EPTH (FEET)O
-
-
5-
-
16-
20-
26-
30-
36-
40-ASSIFICATION]o LOWS/FOOT ICD NDISTURBED ISAMPLE I3 ULK SAMPLE Im MOISTURE IONTENT (%)u
>CSE°OQ.
8t3so-z-r 11125
TEST PIT NO. 4
DESCRIPTION
TOPSOIL: Brown CLAY, Wet, Soft
BEDROCK: SANTIAGO FORMATION;
Light Green Grey CLAYSTONE, with
Occasional Sand, Moist, Stiff,
Blocky, with Orange Staining
@7' Massive, Very Stiff
Total Depth 10'
No Water
No Caving
SOIL TEST
JOBNO-SD1163-001 LOG OF TEST PIT FIQURE: B-23
SAN DIEGO SOILS ENGINEERING. INC.
OATE OBSERVED! 4-28-82 METHOD OF DRILLING! 24" Backhoe
LOGGED BY- KS GROUND ELEVATION! 155' - LOCATION- See Map
EPTH (FEET)Q
10-
16-
20-
25-
30-
36-
40-ASSIFICATIONJ_iU LOWS/FOOT Ia NDISTURBED ISAMPLE I3 ULK SAMPLE ICO
x MOISTUREONTENT (%)u
QJh
z jy
TEST PIT NO. 5
DESCRIPTION
BEDROCK: POINT LOMA FORMATION;
Dark Green-Black Grey, Fine Sandy
SILTSTONE, Moist, Very Stiff to
Hard, Blocky with Dark Red
Staining and Gypsum Seains
@4' Joint: N72 E, 75 NW
Total Depth 5'
No Water
No Caving
SOIL TEST
JOBNO.:SD1163_00 LOG OF TEST PIT FIQURE: B-24
SAN DIEQO SOILS ENGINEERING. INC.
DATE OBSERVED:4-28-82 UFTHOO OF DRILLING- 24" Backhoe
LOGGED BY: KS GROUND ELEVATION: I78' ~ LOCATION: See Map
> DEPTH (FEET)5-
10-
15-
20-
25-
30-
35-
40-CLASSIFICATIONBLOWS/FOOT[UNDISTURBEDSAMPLE 1BULK SAMPLEMOISTURECONTENT (%)IN PLACE DRYDENSITY (PCF) |TEST PIT NO. 6
DESCRIPTION
BEDROCK: SANTIAGO FORMATION;
Light Green Grey, Sandy CLAY-
STONE, Moist, Very Stiff, Red
Stains, Massive
Total Depth 7 '
No Water
No Caving
SOIL TEST
JOBNO.: SD1163_00 LOG OF TEST PIT FIGURE: B-25
SAN DIEGO SOILS ENGINEERING. INC.
DATE OBSERVED:4-28-82 MPTHODOFnoiiiiNn- 24"Backhoe
lOfifSFDBY- KS GROUND PI PUATION- 115' - LOCATION- Sf*ft Map
» DEPTH (FEET)-
6-
16-
20-
85-
30-
35-
40-CLASSIFICATION!BLOWS/FOOT IUNDISTURBED ISAMPLE IBULK SAMPLE IX MOISTURECONTENT (%)IN PLACE DRY 1DENSITY <PCF)ITEST PIT NO. 7
DESCRIPTION
ALLUVIUM: Brown CLAY, Moist, .-'
Firm, with Organics and Root
Holes
BEDROCK: POINT LOMA FORMATION;
*yDark Brown SILTSTONE, Moist,
\Iard, Massive, Blocky
Total Depth 11'
No Water
No Caving
SOIL TEST
joBNo.:SD1163_00 LOG OF TEST PIT FIGURE: B-26
SAN DIEGO SOILS ENGINEERING. INC.
DATE OBSERVED:4-28-82 METHOD OF npii i INO. 24" Backhoe
LOGGED BY! KS GROUND ELEVATION: 106' - LOCATION- Sf><= Map
> DEPTH (FEET)-
6-
10-
20-
25-
30-
36-
40-CLASSIFICATIONBLOWS/FOOT 1UNDISTURBED 1SAMPLE ]BULK SAMPLE 1MOISTURECONTENT (%)IN PLACE DRY 1DENSITY (PCF)TEST PIT NO. 8
DESCRIPTION
ALLUVIUM: Brown Clayey Fine
SAND, Moist, Loose/Silty CLAY,
Moist, Soft to Firm.
Total Depth 15'
No Water
No Caving
SOIL TEST
JOBNO.: SD1163_00| LOG OF TEST PIT FIQURE: B-27
SAN DIEGO SOILS ENGINEERING. INC.
DATE OBSERVED:4-28-R2 uPTHon OP DRILLING- 24" Backhoe
LOGGED BY: KS GROUND ELEVATION? 128' - LOCATION: See Map
> DEPTH (FEET)5-
15-
™
^
-
20-
25-
30-
35-
40-CLASSIFICATIONBLOWS/FOOT!UNDISTURBEDSAMPLE |BULK SAMPLEMOISTURE ICONTENT (%)il
Si*ssg
TEST PIT NO. 9
DESCRIPTION
ALLUVIUM: Grey Brown Silty CLAY,
Moist to Wet, Soft
LEATHERED BEDROCK: POINT LOMA
FORMATION; Brown Grey SILTSTONE,
^Moist, Soft
^BEDROCK: POINT LOMA FORMATION;
Wey SILTSTONE, Moist, Hard
Total Depth 11'
Cemented, Refusal
No Water
No Caving
SOIL TEST
JOBNO^ SD1163_0o| LOG OF TEST PIT (FIGURE: B-28
SAN DIEGO SOILS ENGINEERING. INC.
DATE OBSERVED:4-28-82 METHOO OF DRILLING- 24" Backhoe
LOGGED BY KS GROUND ELEVATION; 118 ' - LOCATION: See Map
> DEPTH (FEET)5-
10-
15-
20-
26-
30-
35-
40-CLASSIFICATION!BLOWS/FOOT 1UNDISTURBED 1SAMPLE |BULK SAMPLE 1X MOISTURE 1CONTENT (%) J£c
£uQQ.
ut
<&*zz%
TEST PIT NO. 10
DESCRIPTION
ALLUVIUM: Brown Grey Silty CLAY,
Moist to Wet, Soft to Firm
Total Depth 14'
No Water
No Caving
SOIL TEST
JOBNO.:SD1163_00| LOG OF TEST PIT FIGURE: B- 2 9
SAN DIEGO SOILS ENGINEERING. INC.
DATE OBSERVED! 4-28-82 METHOD OF DRILLING- 24" Backhoe
LOGGED BY! KS GROUND ELEVATION! 153' - LOCATION! See Map
PIUIUL.
X
&IU
0
-
6-
10-
16-
20-
25-
30-
38-
40-
z
ASSIFICATIO_j
U LOWS/FOOTCO NDISTURBEDSAMPLE3 ULK SAMPLECO MOISTUREONTENT (%)U
°S
Z JrU
TEST PIT NO. 11
DESCRIPTION
ALLUVIUM: Grey Brown Silty CLAY,
Moist, Soft
@11' Seepage
Total Depth 12'
Seepage @ 11 '-12'
No Caving
SOIL TEST
JOBNO.:SD1163_00| LOG OF TEST PIT | FIGURE.- B- 30
SAN DIEQO SOILS ENGINEERING. INC.
OATF ORSFRUFD- 4-28-82 METHOD OF DRILLING^ 24" Backhoe
lOGGEDBYr KS GROUND ELEVATION- 165' - LOCATION- See Map
EPTH (FEET)a
-
5-
15-
20-
25-
30-
35-
40-ASSIFICATIONJ_iU LOWS/FOOT 10 NDISTURBED 1SAMPLE |3 ULK SAMPLE 1m MOISTUREONTENT (%)u
Qi
« rt
TEST PIT NO. 12
DESCRIPTION
ALLUVIUM: Grey Brown Silty CLAY
Moist, Soft
BEDROCK: POINT LOMA FORMATION;
y Grey SILTSTONE, Wet, Stiff,
\Blocky @6" Seepage
t
Total Depth 7.5'
Water @ 6 '-7. 5'
No Caving
SOIL TEST
JOBNO.: SD1163_00| LOG OF TEST PIT F'QURE: B-31
SAN DIEGO SOILS ENGINEERING. INC.
r>ATF ORRFRVFD- 4-28-82 METHOD OF DRILLING: 24" Backhoe
LOGGED BY: KS GROUND ELEVATION: 165 ' - LOCATION! See Map
> DEPTH (FEET)10-
15-
20-
25-
30-
35-
40-CLASSIFICATION!BLOWS/FOOT IUNDISTURBED ISAMPLEBULK SAMPLE IMOISTURECONTENT (%)IN PLACE DRY IDENSITY (PCF) |TEST PIT NO. 13
DESCRIPTION
ALLUVIUM: Brown Grey Silty
s^CLAY, Moist, Soft
BEDROCK: Green Grey SILTSTONE;
Moist, Stiff, Blocky
\
Total Depth 3'
No Water
No Caving
SOIL TEST
JOBNO.:SD1163_00J LOG OF TEST PIT FIGURE: B- 3 2
SAN DIEGO SOILS ENGINEERING. INC.
OAJF oRSPowpn- 4-28-82 METHOD OF DRILLING: 24" Backhoe
LOGGED BY: KS GROUND ELEVATION: 168' - LOCATION: See Map
EPTH (FEET)O
-
5-
10-
15-
20-
26-
30-
38-
40-ASSIFICATION^O LOWS/FOOT!CO NDISTURBED 1SAMPLE |3 ULK SAMPLE 1a MOISTUREONTENT (%)u
aooo.^
^ h^etz
Z JJr
TEST PIT NO. 14
DESCRIPTION
ALLUVIUM: Brown Silty CLAY, Mois
Firm
BEDROCK: POINT LOMA FORMATION;
I Black Grey SILTSTONE, Moist,
\Hard , Cemented
Total Depth 12'
Refusal
No Water
No Caving
SOIL TEST
JOBNO"SDll63-oo| LOG OF TEST PIT | FIGURE: B- 3 3
SAN DIEGO SOILS ENGINEERING. INC.
pATF nPSFRVFH- 4-28-82 METHOD OF DRILLING- 24" Backhoe
LOGGED BY! KS GROUND ELEVATION! 192' - LOCATION! See Map
PUlUl
z
0.Ulo
_
-_
5 —
-
10-
15-
20-
25-
30-
36-
40-
o
ASSIFIC_»O
ooIL
LOWS/Io
ou
r_i
NDISTUSAMP3
Ul
o.
(0
3CD
I*
«u
|z50O
OQ.
•J CO
« o
TEST PIT NO. 15
DESCRIPTION
TOPSOIL: Brown CLAY, Moist, Soft
V
BEDROCK: POINT LOMA FORMATION;
Green Grey SILTSTONE, Moist, Ver?
Stiff, Blocky, Jointed
@3' Joints: N35 E, 80 E; N70 W,
75 W
, Gypsum Seams %" Thick
\@5' Joint: N60 E, 15 W
Total Depth 7'
No Water
No Caving
SOIL TEST
JOBNO-SDll63-oo| LOG OF TEST PIT | FIGURE: B- 3 4
SAN DIEQO SOILS ENGINEERING. INC.
a
i
ij
d
on
PROJFCT UAUF. Car Isbad Research Center TnEH«u un . 16
JOB MO- SD1163-00 nA-rr. 4_?9_R?
EQUIPMENT:
LOeQED BY:
24" Backhoe B1 BUATI/>M. 212' -
KS LOCATION- See Map
DESCRIPTION
Tsa - BEDROCK: SANTIAGO FORMATION;
Light Green Grey CLAYSTONE, Moist To Wet, Firm to Stiff, Fractured.
Orange Staining, Most Common North of Fault.
Fault: N50°E, 72°NW, l/8"-l/4" Brown Remolded Clay and Gypsum in
Fault Zone.
ENGINEERING PROPERTIES
A88IFICATIONU.8.C.8.0
HI
a.
< .
i•
X NOI8TURBEDSAMPLEa
@5'IOI8TURE (%)*EN8ITY (PCF)0
SCALE: 1" = 1' TOPOGRAPHY: TRENCH ORIENTATION: N10°W
till 1 l I l 1 1 1 1 I 1 1 1
V"\
\^
Fauttl l i\ l
T8« \
i i i iJ— L-l-M
T» /:
\ I
\/
m
m
m
•
.
—
TRENCH LOO SAN OIESO SOILS EfMUMEERINe
HATP OBSERVED- 4-29-82 MPTHOD OF DRILLING- 24" Backhoe
IOGGEDBY- KS GROUND ELEVATIONr 260' - LOCATION! Offsitg
P
UlUlu.^^
X1-Q.Ul
O
15--
20-
26-
30-
36-
40-ASSIFICATION!_iu LOWS/FOOT |ffl NDISTURBED ISAMPLE I3 ULK SAMPLE IO
X
JOBNO, SD1163_0 MOISTUREONTENT (%)u
Do."C
§5
2 2*
TEST PIT NO. 17
DESCRIPTION
FILL: Brown Fine-Medium SAND,
Moist to Wet, Moderately Com-
pact, Some Gravel
TOPSOIL: Dark Brown CLAY, Moist,
\Stiff, Roots in Place
Total Depth 10'
No Water
No Caving
SOIL TEST
0 LOG OF TEST PIT FIQURE: B-36
SAN DIEGO SOILS ENGINEERING. INC
DATE OBSERVED:
LOGGED BY: KS
» DEPTH (FEET)5-
-
10-
16-
20-
28-
30-
35-
40-CLASSIFICATION!BLOWS/FOOT IUNDISTURBED ISAMPLE4-29-82 METHOD OP DRILLING- 24" Backhoe
GROUND EL PWATION- 240* - LOCATION- See Map
BULK SAMPLE IJOBNO^SD1163_0(MOISTURE ICONTENT (%)IN PLACE DRYDENSITY (PCF)TEST PIT NO. 18
DESCRIPTION
TOPSOIL: Brown SAND, Dry, Loose
\
BEDROCK: SANTIAGO PEAK VOLCANICS
\Dark Green Metavolcanic, Very
\iard
Total Depth 2'
Refusal
No Water
No Caving
SOIL TEST
} LOG OF TEST PIT FIQURE: B-37
RAN DIFOO SOILS ENGINEERING. INC.
DATE OBSERVED: 4-29-82 METHOD OF DRILLING: 24" Backhoe
LOGGED BY: KS GROUND ELEVATION: 305 ' " LOCATION: See Map
EPTH (FEET)O
-
-
-
5-
~
10-
15-
20-
26-
30-
36-
40-ASSIFICATION!_iu LOWS/FOOT |a NDISTURBED ISAMPLE I3 ULK SAMPLE ICD MOISTUREONTENT (%)u
°s
§i
— inu
TEST PIT NO. 19
DESCRIPTION
TOPSOIL: Brown Sandy CLAY, Moist
k Firm, Blocky
\
BEDROCK: SANTIAGO FORMATION;
Light Green Yellow, Fine-Medium
SANDSTONE, Moist, Medium Dense,
Massive
@5' Bedding: N-S, 2%°W
Light Gre"erT Sandy SILTSTONE,
i Moist, Very Stiff, Massive
Total Depth 81
No Water
No Caving
SOIL TEST
JOBNO-tjD1163_00 LOG OF TEST PIT FIGURE: B- 3 8
SAN DIEQO SOILS ENGINEERING. INC.
DATE OBSERV
LOGGED BY:.> DEPTH (FEET)5-
10-
15-
20-
25-
30-
35-
40-CLASSIFICATION!BLOWS/FOOT Itfo- 4-29-82 MFTwon OF noil i iwn- 24" Backhoe
KS GROUND ELEVATION: 314 '•- LOCATION- See Map
UNDISTURBED 1SAMPLE 1BULK SAMPLE 1MOISTURECONTENT (%)IN PLACE DRYDENSITY (PCF)TEST PIT NO. 20
DESCRIPTION
TOPSOIL: Brown sandy CLAY, Dry
to Moist, Firm, Organics
BEDROCK: SANTIAGO FORMATION;
Yellow White, Fine-Medium SAND-
STONE, Moist, Medium Dense, Cros
Bedded
@6' Bedding Horizontal
Total Depth 9'
No Water
No Caving
SOIL TEST
s
JOBNO.:SD1163_0() | LOG OF TESJ p,T (FIGURE: B-39
SAN DIEGO SOILS ENGINEERING, INC.
DATE OBSERV
LOGGED BY:.> DEPTH (FEET)10-
16-
20-
26-
30-
35^
40-CLASSIFICATION!BLOWS/FOOT,fn- 4-29-82 METHOD OF DRILLING: 24" Backhoe
KS GROUND ELEVATION: 240' - LOCATION: See Map
UNDISTURBEDSAMPLEBULK SAMPLEJOBNO-SD1163-00 MOISTURECONTENT (%)>££2
S>
Iso-z
5g
TEST PIT NO. 21
DESCRIPTION
TOPSOIL: Brown Silty SAND, Dry
to Moist, Loose
BEDROCK: SANTIAGO PEAK VOLCANICS;
Jrown Green Metavolcanic, Very
Hard, Jointed
Total Depth 3'
Refusal
No Water
No Caving
SOIL TEST
LOG OF TEST PIT F'GURE:
B-40
SAN DIEGO SOILS ENGINEERING, INC.
HATE OBSERVED- 4-29-82 METHOD OF DRILLING: 24" Backhoe
LOGGED BY: KS GROUND ELEVATION: 185' - LOCATION: Offsite
P111UJL.^*
Z
0.illo
-
-
-
~
-
-
10-
15-
20-
25-
30-
36-
40-ASSIFICATION!_iu LOWS/FOOT ICO NDISTURBED ISAMPLE I3 ULK SAMPLE ICD MOISTUREONTENT (%)u
°s
z ™
TEST PIT NO. 22
DESCRIPTION
TOPSOIL: Brown Silty Sandy CLAY,
Moist, Firm
X
BEDROCK: SANTIAGO FORMATION;
Light Yellow Green, Fine-Medium
SANDSTONE, Moist, Medium Dense
V Massive\
Green CLAYSTONE, Moist, Stiff,
^Massive, Fractured. Contact
\Horizontal
Total Depth 8 '
No Water
No Caving
SOIL TEST
JOBNOJSD1163_00 LOG OF TEST PIT FIGURE: B-4l
SAN DIEGO SOILS ENGINEERING. INC.
HATE OBSERVED- 4~29~82 METHOD OF DRILLING- 24" Backhoe
LOGGED BY: KS GROUND ELEVATION- 172' - LOCATION- Offsite
^
UlUlL.
Z1-Q.
Ulo
-
-
-
6-
"
-
10-
16-
20-
25-
30-
36-
40-
•z.n
ASSIFICATK_iU
H
LOWS/FOOm
a
NDISTURBESAMPLE3
Ul
a.
<CO
X_)
3a MOISTUREONTENT (%u
>c0=0OQ.
^Si
z ™
TEST PIT NO. 23
DESCRIPTION
TOPSOIL: Light Brown Sandy CLAY,
,Dry, Firm
BEDROCK: SANTIAGO FORMATION;
Light Green Fine Sandy SILTSTONE,
Morst, Stiff /Light Yellow Fine-
Medium SANDSTONE, Moist Medium
Dense, Massive
.^'-8' Fault: N10 E,70 W; %"
stone West of Fault and
\ Silstone East of Fault
Total Depth 8'
No Water
No Caving
SOIL TEST
JOBNO-SDll63-Oo| LOG OF TEST PIT JFIGURE: B-42
SAN DIEQO SOILS ENGINEERING. INC.
DATE OBSERVED:4-29-82 METHOD OF DRILLING- 24" Backhoe
LOGGED BY: KS GROUND ELEVATION: 162' - LOCATION: Offsite
> DEPTH (FEET)5-
10-
-
_
15-
20-
25-
30-
35-
40-CLASSIFICATION!BLOWS/FOOT IUNDISTURBEDSAMPLEBULK SAMPLEJOBNO,SD1163_OC MOISTURECONTENT (%)fcc
£oQo.
w'?&
*2
5g
TEST PIT NO. 24
DESCRIPTION
TOPSOIL: Dark Brown Silty SAND
Moist, Loose
BEDROCK: SANTIAGO FORMATION;
White Fine-Medium SANDSTONE,
Moist, Medium Dense, Massive,
Cross Bedding (0 -20 )
Total Depth 8'
No Water
No Caving
SOIL TEST
) LOG OF TEST PIT FIQURE: B-43
SAN DIEGO SOILS ENGINEERING. INC.
HATF OBSERVED- 4-29-82 METHOD OF nRii L ING- 24" Backhoe
LOGGED BY: KS GROUND ELEVATION: 122' - LOCATION- Off Site
EPTH (FEET)O
-
5-
-
-
-
10-
15-
20-
25-
30-
36-
40-ASSIFICATION!.ju LOWS/FOOT ICD NDISTURBED ISAMPLE |3 ULK SAMPLE ICO MOISTURE IONTENT (%)u
°S
— o
TEST PIT NO. 25
DESCRIPTION
ALLUVIUM: Dark Brown Clayey SAND
Sandy CLAY, Moist, Soft, Organic
in Top 1'
BEDROCK: SANTIAGO FORMATION;
Light Brown Yellow Clayey Silty
^ANDSTONE, Moist, Medium Dense,
\Massive
Total Depth 7'
No Water
No Caving
SOIL TEST
JOBNO-SD1163-00 LOG OF TEST PIT FIGURE: B- 4 4
SAN DIEGO SOILS ENGINEERING. INC.
PROJECT MAUP? Carlsbad Research Center TR
JOB MO- SD1163-00 PA
CMCH yo.; 26
rr. 6-23-82
EQUIPMENT: 24" Backhoe B1 BUATIrtil. 176' - - 224' ±
LOQQED BY:JFK See Map, Located in Dozer
LOCATiow- Pit 1
DESCRIPTION
Tsa - BEDROCK:SANTIAGO FORMATION;
Green and Greenish-Brown Clayey SILTSTONE, Slightly Moist, Stiff,
Yellow Staining, Slightly Fractured, Slightly Undulating Bedding'
Brown, Light Brown and Yellow Silty SANDSTONE/SANDSTONE, Slicrhtly
Moist to Moist, Dense, Massive to Poorly Bedded
SCALE: 1" = 20'
till
• Match
- Line
1 I
'.
TOPOGRAPHY:
1
?sasir
.1111
:stone
^
1 1 1 1
^Fossilif«
-<^T . „
1 1 1 1
rous Zone
— ' ' __' — -
'.
ENQINEERINa PROPERTIES
CLASSIFICATIONU.S.C.S.HI
a.
\
•UNDISTURBEDSAMPLEMOISTURE (%>DENSITY (PCF)TRENCH ORIENTATION: H82°E
till
'sa Sands
-Bedding:
N10°E,1(
>^-' ••••••••-•
I I I I
•
.one
!f Badi
^ Nea]
»
i I I i
K
ft
ing:
Horizont;1
1 1 1 1
-
TRENCH LOO SAN ME»0 SOILS EIMNEEIIINO
PROJECT MAME* Carlsbad Research Center TRENCH
JOB *M»- RD1 1 fi?-nn _ PAT*- 6-23-82
26 (Continued)
EQUIPMENT:.24" Backhoe
BY:JFK
ELEVATION:.
LOCATION:.
176' - - 224' -
See Map
DESCRIPTION
ENONMEERINO PROPERTIES
is
o
3
s<so «
MlO
See Trench Log 26
SCALE: 1"= 20 TOPOQRAPHY:TRENCH ORIENTATION: N82 E
Tsa
Siltstonb
TRI Loa SAN MESO SOILS ENSUKCRINS
PROJECT MAUE. Carlsbad Research Center TREN<
,oBWn- SD1163-00 «A«.
EQUIPMENT:
LOGGED BY:
24" Backhoe
JFK
EL
LO
EVA
CAT
!M Mft- 27
6-23-82
riAu. 174' -
inij. See Map
DESCRIPTION
TOPSOIL: Dark Brown Silty CLAY, Moist, Soft
Tsa - BEDROCK: SANTIAGO FORMATION; Light Brown-Yellow Brown SANDSTONE,
Slightly Moist, Dense, Massive to Poorly Bedded
Kpl - BEDROCK: POINT LOMA FORMATION; Light Grey Clayey SILTSTONE, Slightly
Moist, Firm to Stiff, Fractured, Massive
Mottled Grey, Red, Brown and Light Grey Silty CLAYSTONE,
Moist, Soft, Very Weathered, Plastic
SCALE: 1" = 2 0 ' TOPOGRAPHY:
I I I I I I I Li
Contact:
N5°W,5°-3
Tsa
•ilvl-U.-.-,
— " h*0°SW Kp3
Si]
-dl-vj '-'•'-•
tstone
=*
Kl
C]
ENQINEERINQ PROPERTIES
CLASSIFICATIONU.8.C.S.BULK SAMPLEUNDISTURBEDSAMPLETRENCH ORIENTATION: Ng 2 °W
BfcsMa
>i
.aystone
.-L^db^.
Fault:
N10°E,80
Top sol
°SE ;
*
^.1^41^.1^
•^ \
Kpl
Clayst
i 1 1 1 1
one MOISTURE (%)DENSITY (PCF)III)
-
-
TRENCH LOO SAN DIE0O SOILS DMINeERINC
DATE OBSERVED: 6-23-82 METHOD OF DRILLING: 24" Backhoe
L
LOGGED BY: RS GROUND El OVATION: 172> ~ LOCATION: SeS MaP
DEPTH (FEET)-
5-
-
10-
-
.
-
15-
20-
25-
30-
35-
40-CLASSIFICATIONBLOWS/FOOTUNDISTURBEDSAMPLE ]BULK SAMPLEMOISTURECONTENT (%)IN PLACE DRYDENSITY (PCF) 1TEST PIT NO. 28
DESCRIPTION
TOPSOIL: Brown Silty CLAY, Moist
Soft
BEDROCK: POINT LOMA FORMATION;
Mottled Light Grey Green and Red
Silty CLAYSTONE, Moist, Soft to
Firm, Massive, Weathered
Total Depth 7'
No Water
No Caving
SOIL TEST
JOBNO.^D1163_00 | LOG OF TEST PIT (FIGURE: B-48
SAN DIEGO SOILS ENGINEERING. INC.
DATE OBSERV
LOGGED BY:_> DEPTH (FEET)6-
10-
16-
20-
25-
30-
36-
40-CLASSIFICATION!BLOWS/FOOTrpo- 6-23-82 MfTHon OF DRILLING- 24" Backhoe
JFK QROUND ELEVATION! 167' - LOCATION! See Map
UNDISTURBED 1SAMPLEBULK SAMPLE 1MOISTURE 1CONTENT (%)IN PLACE DRY 1DENSITY (PCF) |TEST PIT NO. 29
DESCRIPTION
TOPSOIL: Brown Clayey SILT,
Moist, Soft
BEDROCK: POINT LOMA FORMATION;
Grey Clayey SILTSTONE, Slightly
Moist, Stiff to Hard, Upper 4'
Mottled and Weathered, Harder
Fractured and Massive Below
Total Depth 9'
No Water
No Caving
SOIL TEST
JOB NO.: SD1163_oo| LOG OF TEST PIT FIGURE-. B-49
SAN DIEGO SOILS ENGINEERING. INC
DATE OBSERVED:6-23-82 MPTHon OP DRILLING- 24" Backhoe
LOGGED BY: JFK GROUND ELEVATION- 164' - LOCATION: See Map
• DEPTH (FEET)6-
10-
16-
20-
26-
30-
36-
40^CLASSIFICATION!BLOWS/FOOT |UNDISTURBED ISAMPLE |BULK SAMPLEMOISTURE 1CONTENT (%)°&TEST PIT NO. 30
DESCRIPTION
BEDROCK: POINT LOMA FORMATION;
Dark Grey SILTSTONE, Slightly
Moist, Hard, Fractured, Massive
Total Depth 6'
No Water
No Caving
SOIL TEST
JOBNOJSD1163_00| LOQ OF T£ST p|T FIGURE: B_50
SAN DIEGO SOILS ENGINEERING. INC.
DATE OBSERVED:6-23-82 METHOD OF DRILLING: 24" Rackhop
ICGGEDBV: JFK GROUND ELEVATION: 155' - LOCATION: See Map
> DEPTH (FEET)5-
10-
15-
20-
26-
30-
35-
40-CLASSIFICATION!BLOWS/FOOT IUNDISTURBED 1SAMPLE |BULK SAMPLE 1JOB NOJSD1163_OQ MOISTURE 1CONTENT (%)>-cKOOCL
^&
*2z%
TEST PIT NO. 31
DESCRIPTION
TOPSOIL: Brown Silty SAND,
Slightly Moist, Loose
BEDROCK: SANTIAGO FORMATION;
Brown SANDSTONE, Slightly Moist,
Dense, Massive
Total Depth 12'
No Water
No Caving
SOIL TEST
LOG OF TEST PIT FIQURE: B-51
SAN DIEGO SOILS ENGINEERING. INC.
DATE OBSERV
LOGGED BY:.> DEPTH (FEET)5-
m—
20-
26-
30-
36-
40-CLASSIFICATION|BLOWS/FOOT |PO- 6-23-82 METHOD OP DRILLING- 24" Barkhnp>
JFK GROUND ELEVATION: 142' - LOCATION: See Map
UNDISTURBED 1SAMPLE |BULK SAMPLE 1JOBNO.:SD1163_0 MOISTURECONTENT (%)IN PLACE DRYDENSITY (PCF)TEST PIT NO. 32
DESCRIPTION
''ILL; Brown Silty CLAY, Moist
firm
Greenish Brown CLAY, Moist to Wet
Soft to Firm, Chunks of Green
Siltstone Interbedded.
JEDROCK: SANTIAGO FORMATION;
Brown SANDSTONE, Slightly Moist,
)ense
Total Depth 15'
No Water
No Caving
SOIL TEST
3 LOG OF TEST PIT FIQURE: B-52
SAN DIEGO SOILS ENGINEERING. INC.
DATE OBSERVED:6-23-82 METHOD OF DRILLING- 24"Backhoe
LOGGED BY: JFK GROUND fl PVATION- 124' - LOCATION: See Map
> DEPTH (FEET)-
10-
15-
20-
26-
30-
36-
40-CLASSIFICATIONBLOWS/FOOTUNDISTURBEDSAMPLEBULK SAMPLEMOISTURECONTENT (%)IN PLACE DRYDENSITY (PCF)TEST PIT NO. 33
DESCRIPTION
TOPSOIL: Brown sandy CLAY, Moist
Firm, Porous
BEDROCK: SANTIAGO FORMATION;
Brown SANDSTONE, Moist, Dense
Massive
Contact N5°E, 5°NW
POINT LOMA FORMATION; Green
Clayey SILTSTONE, Moist, Firm to
Stiff
Total Depth 12'
No Water
No Caving
SOIL TEST
JOBNO^ SD1163-00| LOG OF TEST PIT [FIGURE: B-53
SAN DIEGO SOILS ENGINEERING. INC.
PATF OBSERVED- 6-23-82 METHOD OF DRILLING- 24" BaCkhOG
LOGGED BY: JFK GROUND ELEVATION: 104' - LOCATION: See Map
> DEPTH (FEET)5-
15-
20-
26-
30-
35-
40-CLASSIFICATION!BLOWS/FOOT II UNDISTURBED ISAMPLE IBULK SAMPLE IMOISTURE ICONTENT (%)IN PLACE DRYDENSITY (PCF)TEST PIT NO. 34
DESCRIPTION
ROAD FILL: El Camino Real; Brown
Silty SAND, Moist Moderately
Compact. Contact Free of
s. Vegetation
X
ALLUVIUM: Grey Silty CLAY, Moist
Firm
Total Depth 10'
No Water
No Caving
SOIL TEST
JOBNO.:SD1163_00| LOG op TEST p,T FIGURE: B-54
QAM nicAn <$nn <t PNniMPrniNn inc.
PATE OBSERVED: 6-23-82 MPTHon OP non i iwft- 24" Rsckhop
lOeGEDBY: JFK GROUND ELEVATION: 173' - LOCATION- See Map
EPTH (FEET)O
5-
-
.
15-
•
-
-
20-
25-
30-
35-
40-
0
oiZ
COCO<_iu LOWS/FOOT Iffl NDISTURBED ISAMPLE |3 ULK SAMPLE Ia MOISTUREONTENT (%)u
da.
UI*"*o>
Z •£a
TEST PIT NO. 35
DESCRIPTION
TOPSOIL: Brown Sandy SILT,
\Slightly Moist, Soft
BEDROCK: SANTIAGO FORMATION;
I Yellow Brown and Light Brown
\SANDSTONE, Slightly Moist, Mediu
\ Dense, Massive to Poorly Bedded
\ Contact: N4°E, 10°NW
POINT LOMA FORMATION; Light Grey
Clayey SILTSTONE, Slightly Moist
i Firm, Fractured, Massive
Total Depth 10'
No Water
No Caving
SOIL TEST
JOBNO.-SD1163_00 LOG OF TEST PIT FIGURE: B_55
SAN DIEGO SOILS ENGINEERING. INC.
M«JMT MAU* Carlsbad Research Center TRPHrH Mrt. 1
JOB MO, SD1163-00 nATB. 6-2-82
EQUIPMENT:.D-8 Bulldozer F) FVATU>M. 178' - - 224' -
LQflHIED PV- KS tOGATinM> See MaP
DESCRIPTION
TOPSOIL: Light Brown Silty CLAY, Moist, Firm
Tsa- BEDROCK: SANTIAGO FORMATION;
Green and Brown SILTSTONE/Clayey SILTSTONE, Moist, Stiff,
Fractured with Orange Staining
Brown with Green, Silty Fine-Medium SANDSTONE, Moist, Medium
Dense, Fractured with Black Organic Seams, Gypsum Zones and
Red Staining.
ENQINEERINQ PROPERTIES
I
Srf
gSIk •
*%»*
<
JO
HI
a.
<
_i
3•
oin
ISs<0«z3
I
HI
H
Co
>i*
5zino
SCALE: 1"= 20' TOPOGRAPHY: TRENCH ORIENTATION: N82UE
•
I I I I 1 1 1 1 1 1 1 1
Tsa
Gre
O -i 1oil
1 1 1 1
xS^^^«
_stone j/
l 1 1 A
Tsar
Brown
Clayey
Silstone
/Topsoil
r^F^?^
Tsa-
Green
Silston
'"•Tirrj—t- 1 i 1
Tsa X^^^^i^^-^
2 Brownl ^ ~"
Sils€
Horiz
•
ane
sntal
.^Sops
*=C^i=T±=rr— .
^^^ — i=:
•
Dil
^rr-^T^d
^^^
•
TREi LOO SAN DIEM SOILS DMNECRUM
PROJECT MAug;Carlsbad Research Center TRENCH MO? 1 (Continued)
SD1163-00 *^m. 6-2-82JOS NOJ
EQUIPMENT:.
LOOMED §V:.
DATE:.
D-8 Bulldozer
KS
ELEVATION:.
LOCATION: _
178' - - 224' -
See Map
DESCRIPTION
ENGINEERING PROPERTIES
<
u
Ul
a.
QIII
o «
UlQ
See Trench Log 1
SCALE: 1" =TOPOGRAPHY:TRENCH ORIENTATION:
I I I I I I I I I I I I I I I
il
Tsa
Light-f ~i-* Ts£Sandy SiJJtstone fir<.wn Sandstc ne_
TRENCH LOG SAN DIEGO SOILS CNGJNEERINO
PROJECT JIAUB? Carlsbad Research Center TR
jrtaMo. SD1163-00 nA
§ HCH MQ.; 2
6-2-82
EQUIPMENT: D~8 Bulldozer KI BUATIAM. 210' - - 214' -
LOMEO BY:KS i oGATinit* See Map
DESCRIPTION
TOPSOIL: Mottled
Tsa - BEDROCK: SANTIAG(
Brown Silty CLAY, 'Moist to Wet, Soft
D FORMATION;
Light Pale Green Fine Sandy Clayey SILTSTONE, Moist,
Very Stiff, Massive with Red-Orange Staining in Fractures
Light Blue Green Silty CLAYSTONE, Moist to Wet, Firm to
Stiff
SCALE: 1M = 20'
N^
ENGINEERING PROPERTIES
CLASSIFICATIONU.8.C.8.BULK SAMPLEUNDISTURBEDSAMPLEMOISTURE (%)DENSITY (PCF)TOPOORAPHY: TRENCH ORIENTATION: N52°W
Topsoil '
•
«
V
1 1 J 1
" .
- Tsa
. Siltsto]
— 1 1 1 h
- — .
FSLU.
le N50*'£,80°^
JTopsoil•^1 f I 1
•
—
Tsa
Claystone
•
—7
•-
TftlNCMLOa SAN DICOO SOILS EN01NCERIN0
DATE OBSERVED:6-2-82 UPTHOD OF DRILLING- D- 8 Bulldozer
i
LOGGED BY: KS OPOIIND Fl FVATION- 170' - LOCATION: See MaP
> DEPTH (FEET)5-
10-
-
15-
20-
26-
30-
35-
40-CLASSIFICATION!BLOWS/FOOT IUNDISTURBED ISAMPLE |BULK SAMPLE IMOISTURECONTENT (%)IS
On."CStis
sg
TRENCH NO. : 3
DESCRIPTION
TOPSOIL: Dark Brown CLAY, Wet
Firm
BEDROCK: SANTIAGO FORMATION;
Green with Red Brown Mottling
.CLAY, Moist, Firm-Stiff
Total Depth 6'
No Water
No Caving
SOIL TEST
JOB NO.:SD1163_00 LOG OF TEST PIT FIGURE: B-59
SAN DIEQO SOILS ENGINEERING. INC.
APPENDIX C
LABORATORY TESTING
A. Index Tests
Moisture content and dry density determinations were made
for most ring samples. Results of moisture-density deter-
minations are shown on the Logs of Borings, included in
Appendix B of this report.
Results of Hydrometer Tests and Sieve Analyses performed
in accordance with ASTM: D 422-72, on portions of repre-
sentative samples are presented in Figures C-l through C-4.
Results of Atterberg Limits, consisting of both liquid
limit and plastic limit analyses are plotted on the Plas-
ticity Chart in Figure C-5. Atterberg Limits were performed
in accordance with ASTM: D 423-72. The test results are
also recorded on the grain size curves.
B. Consolidation Tests
Consolidation tests were performed on remolded claystone
(Figure C-6), remolded Sandstone (Figure C-7), and alluvium
(Figures C-8 and C-9). Water was added to the apparatus
at the load indicated on the consolidation curves. The
consolidation test results are presented on Figures C-6
through C-9.
C. Direct Shear Tests
Direct shear strength tests were performed on selected
intact ring and remolded samples. Test results for intact
siltstone/claystone and intact sandstone are presented in
Figures C-10 and C-ll respectively. Remolded siltstone,
claystone and sandstone direct shear tests are presented
in Figures C-12, C-13 and C-14. Remolded samples were
compacted to 90% maximum dry density at optimum moisture
content. Direct shear samples were inundated with water
and allowed to come to equilibrium prior to shearing.
D. Expansion
Expansion tests were performed on representative samples
of the on-site soils remolded and tested under a surcharge
of 144 pounds per square foot in accordance with the Uni-
form Building Code Standard No. 29-2. The test results
are summarized on Table 1, Figure C-15.
E. Maximum Density/Optimum Moisture Content
The maximum dry density/optimum moisture content relation-
ship was determined for typical samples of the on-site
soils. The laboratory standard used was ASTM: D 1557-78.
The test results are summarized on Table 2, Figure C-15.
IJOB NO.:I SD1163-00PARTICLE SIZE ANALYSISFIGURE: 1C-1 |3t
100
00
80
70
m 60aomzH 60•o
CO
CO
Z 4O
O
3O
2O
g
GRAVEL SAND
COARSE
f4" 1/2" 1/4" 4 '
MEDIUM
10
10.0
BORING N(
2
D. DEPTH (FEET)
20
J
20 <
AM
FINE
JIEVE 8IZES-
0 1C
A A
SI
J.8. 8u
3VE
TAI
2
=cy• i
SILT CLAY
YDARD
00
f-
\
•^
VL.X"»
Sc ^O^^
\
XV7v
" \
V
^X.I•H
\
rDE
v
^M
OMEr
\
\
'ER
v\\
Q>
100
BO
80
PERCENT PASSINGO O O O O O nK«to«e)M?c1.0 0.1 .01 .001
PARTICLE SIZE-MILLIMETERS
SYMBOL LI
0 A
QUID LIMC
—
r PLASTICITY INDEX
_
CLASSIFICATION
Santiago Formation
REMOLDED CLAYSTONE (CH)
CO>z
omoo
COO
FCO
ENGINEERING. INC.IJOB NO.:SD1163-00PARTICLE SIZE ANALYSIS(FIGURE: 11 C-2 13)
100
90
AA
3 «om CO
9
Om
H tenou•o>CO
CO
Z 40o
ZU
Q
GRAVEL SAND
COARSE
'4" 1/2" 1/4" 4 '
1O.O
BORING NC
3
i
I DEPTH (FEET)
3
MEDIUM | FINE
SILT CLAY
SIEVE SIZE8-U.S. STANDARD
> 20 40 100 200
a -.
1.0
SYMBOL LIC
A
*s
\
\
\ 1
\
\
1/t^-J
\\
\
\
::r.
\
\N
\
A
i
v
0.1 .(
PARTICLE SIZE-MILLIMETERS
)UID LIMI1
-
T PLASTICITY INDEX
—
1 .0(
CLASSIFICATION
Santiago Formation
REMOLDED SILTY FINE SANDSTONE (SM)
100
90
80
70
•oeo jj
om
60 "*•o
CO
CO
40 Z0
30
20
10
0
)1
(JOB NO.:I SD1163-00PARTICLE SIZE ANALYSISFIGURE: 1C-3 |» 0 0 0 O 0 0 0 0 tOe»«OK«tf>*C»CPERCENT PASSING*V
1U
f%
GRAVEL SAND
COARSE
f4" 1/2" 1/4" 4
10.0
BORING N(
6
f
S —•— .
MEDIUM FINE SILT CLAY
SIEVE 8IZE8-U.S. STANDARD
10 20 40 100 200
^
5. DEPTH (FEET)
10
^ =
1.0
SYMBOL LI
O A
\ !r «.•>,•/,-G
*>x
IEV
'S
^t
SJ
LXi
^
>
N
\
\
si.
y^\•v /^i\°\%
\
\
•I
^
^M
YI
V
)R(
\
DME
\
r
TER
\
o'.i .01 .0!
PARTICLE SIZE-MILLIMETERS
QUID LIMC
_
T PLASTICITY INDEX
_
CLASSIFICATION
Point Loma Formation
REMOLDED SILTSTONE (CD
ion
00
60
70
•o60 23)om
Z
60 -••o>m09
40 z0
30
20
10
0
)1
SAN DIEGO SOILS(•NGINFPRINO INCIJOB NO.:SD1163-00PARTICLE SIZE ANALYSIS1 FIGURE:C-4"S S 8 2 S 8 S SPERCENT PASSINGGRAVEL
f4" 1/2" 1/4" j
SAND
COARSE
V 1
•it.
10.0
BORING NO.
7
DEPTH (FEET)
5
MEDIUM |FINE SILT CLAY
SIEVE 8IZE8-U.8. STANDARD
0 20 40 100 200
^~^~1
1.0
SYMBOL LI
0 A
! s-
I
«.•-.•v -s
*^>
:EVE
\
^
^N'\
s5)\
O Al^-HYDRO
v
^<
0.1 .(
PARTICLE SIZE-MILLIMETERS
QUID LIMIT
42
PLASTICITY INDEX
30
o.E
f ^
. j
T
s,
*
K
f*^^^
^X
1 .0(
CLASSIFICATION
Alluvium (CD
100
00
80
70
60 "I9
Omz
60 H
•D
CO
CO
40 zO
30
20
10
0
)1
PLASTICITY INDEX (%)o*>. 8 § g £ g gSYMBOL
A
O
V
O
PLASTICITY CHART
CL-ML '///
ML
CL
0/Asr
\
S
S
MLo
™^*1 Y^" f
S
/
r OL
/
CH
^
^f
MH
OH
4
f
/
) 10 20 30 40 50 60 70 80 90 100
LIQUID LIMIT (%)
BORING
NO.:
1
2
6
7
SAMPLE
DEPTH
(feet)
10
10
20
5
NATURAL
WATER
CONTENT
%
22
9
18
20
LIQUID
LIMIT
%
43
21
46
42
PLAS-
TICITY
INDEX
%
31
9
31
30
PASSING
NO.: 200
SIEVE
%
82
LIQUIDITY
INDEX
%
32
-33
10
27
UNIFIED
C|CAT%rK/A 1 HJIM
SYMBOL
CL
CL
CL
CL
JOB NO: SD1163-00 1 DATE: Auqust, 1982 IFIGURE: C-5
SAN niprso «sr»n
SANTIAGO FORMAT I ON- REMOLDED CLAYSTONE
Sample compacted at 90% maximum dry density at optimum
moisture content.EXPANSION (%)j b3 0 O O O 0,-• w « « e(%) NOiivanosNOOBORINQ NO.
2
--^
VN
QS
^
DEPTH (FEET)
20
\\
\
>
^
\
X
s
s
s
\
^
SYMBOL
O
£ Vv' X\\^
c \\
")"'WATEI
ADDEI
EXPLANATION
FIEL
)
\
\
\
X
\
-<)
8 OOOO O O O O Oo o o o o oooo•» a « « u> o oooo*• N n « 10
NORMAL LOAD (PSF)
JOB NO.:
SD1163-00
RtB
D MOISTURE
PLE SATURATED
OUND
§0000 oOOOO OSO O O O OOOOO ON 0) * IO O
LOAD CONSOLIDATION TEST FIGURE:
C-6
SAN DIEGO SOILS ENGINEERING. INC.
SANTIAGO FORMAT ION- REMOLDED SANDSTONE
Sample compacted to 90% maximum dry density at optimum
moisture content.EXPANSION (%)•^> bCONSOLIDATION (%)f» .*• f» !« r*oo b b P tBORING NO.
3
"• —^f • J
XX
DEPTH (FEET)
20
^
"?>
^
*"S,
*•*•*
"*\
^
SYMBOL
O
N WATEXvx
X —
EXPLANATION
FIEl
1 AD
)
"^,
•- ••
DE
1*
)
)
o o o o o o oooo5 oooo o oooo•" cv e» « u> o oooo^ W » * IO
NORMAL LOAD (P3F)
JOB NO.:
SD1163-00
REB
D MOISTURE
PLE SATURATED
OUND
O OOOO OO OOOO O§0000 ooooo o*• en o * 10 o
LOAD CONSOLIDATION TEST FIGURE:
C-7
SAN DIEGO SOILS ENGINEERING. INC.
ALLUVIUM
EXPANSION (%)> bCONSOLIDATION (%)P ^ « !» ."b b b b o cBORING NO.
7
^^•\
\
DEPTH (FEET)
5
N
\
^^I
\
^
^
s
\
\
s
\
SYMBOL
O
ta.
(
\.
\\\
C\(
EXPLANATION
FIEl
Xs I
)WA
V
k
Vi
TF,
^
^
D
\
\
^
~]
\
»\
j^ t
\
f^; §§§§ § | 1 | § ~
NORMAL LOAD (PSF)
JOB NO.:
SD1163-00
RtB
.D MOISTURE
IPLE SATURATED
OUND
i I 11! I
LOAD CONSOLIDATION TEST FIGURE:
C-8
SAN DIEGO SOILS ENGINEERING. INC.
ALLUVIUM
EXPANSION (%)> bCONSOLIDATION (%)P ^ >»!».-*0 O OOP CBORINQ NO.
8
^—•»,
DEPTH (FEET)
15
X
\
"vc
V
\
\
\
w
^\
\s
SYMBOL
O
)\,,v\ix
EXPLANATION
FIEl
u REB
\
)-vV
V
V
AT I
x
1
\,\
•^
D
Vi
D3
\
t ,
8 OOOO O OOOOO O O O O OOOO"• N a « u> o oooo*• w o •* 10
NORMAL LOAD (PSF)
JOB NO.:
SD1163-00
)
.D MOISTURE
IPLE SATURATED
OUND
O OOOOO OOOOSO O 0 Oo o o o*• w o •» 10
LOAD CONSOLIDATION TEST 100000FIGURE:
C-9
SAN DIEQO SOILS ENGINEERING. INC.
3000
2000
ena
enena)
en
<u
1000
BORING
NO.
DEPTH
(FEET)COHESION.(PSF)
400
\j
ANGLE OF
FRICTION.0
32
SAMPLE DESCRIPTION
LOMA FORMATION
INTACT SILTSTONE/CLAYSTQNE
7
A -Peak
Shear
Stress
O -Ultimat
Shear
Stress
1000 2000
Normal Stress (psf)
3000 4000
OB NO.:nn-00 DATE:
August, 1982 I FIGURE;C-10
SAN DIEGO SOILS ENGINEERING. INC.
3000
2000
u-iw
enw
-p
CO
0)
1000
BORINQ
NO.
DEPTH
(FEET)
3-30
COHESION.(P3F)
650
ANGLE OF
FRICTION.0
31
SAMPLE DESCRIPTION
SANTIAGO FORMATION
INTACT SANDSTONE
Peak
0=31° C=6
Ultimate
0=32° C=0
0 psf
1000 2000
Normal Stress (psf)
3000 4000
OB NO.:SD1163-00 DATE:August, 1982 FIGURE:C-ll
SAN DIEGO SOILS ENGINEERING. INC.
3000
2000
4-4
(0
to
(0
OJ^•<jen
0).cCO
id
0)
1000
BORINGNO.DEPTH(FEET)COHESION.(PSF)
400
ANGLE OF
FRICTION.0
24
SAMPLE DESCRIPTION
POINT LOMA FORMATION
REMOLDED SILTSTONE_
1000 2000
Normal Stress (psf)
3000 4000
OB NO.:SD1163-00 DATE:August, 1982 FIGURE:C-12
SAN DIEGO SOILS ENGINEERING. INC.
3000
2000
toa
U)w
Q)
^-U
CO
Q)
Q)0,
1000
BORINGNO.DEPTH(FEET)
20
COHESION.
(P8F)
850
ANGLE OFFRICTION.0
17
SAMPLE DESCRIPTION
SANTIAGO FORMATION
REMOLDED CLAYSTONE
1000 2000
Normal Stress (psf)
3000 4000
OB NO.:SD1163-00 DATE:August, 1982 FIGURE:C-13
SAN DIEGO SOILS ENGINEERING. INC.
3000
2000
to
CO
W
S-l(0
0)
1000
BORINQ
NO.
DEPTH
(FEET)
20
COHESION.
(PSF)
200
ANGLE OF
FRICTION.0
32
SAMPLE DESCRIPTION
SANTIAGO FORMATION
REMOLDED SANDSTONE
1000 2000
Normal Stress (psf)
3000 4000
OB NO.:SD1163-00 DATE:
August. 1982
FIGURE:
C-14
SAN DIEGO SOILS ENGINEERING. INC.
TABLE 1
RESULTS OF EXPANSION TESTS
(U.B.C. STANDARD 29-2)
TEST
LOCATION
B-l at 10'
B-2 at 20'
B-3 at 3'
SOIL
TYPE
Remolded
Siltstone
Remolded
Claystone
Remolded
Silty Sandstone
EXPANSION
INDEX
103
66
48
POTENTIAL
EXPANSION
High
Medium-High
Low- Medium
TABLE 2
MAXIMUM DENSITY/OPTIMUM MOISTURE TESTS
(A.S.T.M. TEST PROCEDURE D 1557-78)
TEST
LOCATION
SOIL
TYPE
MAXIMUM DRY
DENSITY (pcf)
OPTIMUM MOISTURE
CONTENT (%)
B-2 at 20'
B-3 at 20'
B-7 at 5'
Remolded
Claystone
Remolded
Silty Sandstone
Remolded
Alluvium
112
114
117
12
16
15
JOB NO: SD1163-00 DATE: August 1982 FIGURE: C-15
APPENDIX D
SLOPE STABILITY ANALYSES
Appendix D summarizes results of slope stability analyses.
Gross stability analyses were performed for compacted slopes
(maximum height of 80 feet) using Janbu's stability chart and
the shear strength parameters for remolded siltstone presented
in Figure C-12. Gross stability analyses were also performed
for cut-slopes (maximum height of 80 feet) in siltstone using
the shear strength parameters for intact siltstone presented
in Figure C-10. Stability analyses are presented in Figures
D-l and D-2.
Surficial stability analyses were performed assuming an infinite
slope with seepage parallel to the slope face. To determine
the shear strength for surficial stability analyses, drained
Direct Shear tests were performed on remolded siltstone samples
(compacted at 90% dry density) at low normal loads (75-150 psf)
and the samples were permitted to swell prior to shearing.
Shearing of samples provided at a strain rate of on the order
of 7 percent/hour. The surficial stability analysis for a
2:1 slope with three feet of seepage is presented in Figure D-3
and the factor of safety versus depth of seepage for different
slope ratios are presented in Figure D-4.
10 15 20 25 30
SLOPE •< (DECREES)
35 40 45
SLOPE DATA:
Slope Height (H) 80 feet Friction Angle (0) 24 degrees
Slope Ratio H) (2;1) 26. Degrees Cohesion (C) 400 psf
Unit Weight (J)120 pcf
FACTOR'OF SAFETY (F.S.):
F.S.N, C
10.7 N, =from chart
1.54 Fill Slope (Remolded Siltstone)
GROSS STABILITY ANALYSIS (JANBU'S CHART)
JOB NO.:SD1163-00 IDATE:August ,1982 FIGURE:D-l
10 15 20 25 30
SLOPE «c (DEGREES)
35 40
SLOPE DATA:
Slope Height (H) 80 feet Friction Angle (0) 32 degrees
Slope Ratio (•<) (2;1) 26. Degrees Cohesion (C) 400 psf
Unit Weight (*)125 pcf
FACTOR'OF SAFETY (F.S.)
F.S.
yHtan0 _
r C
15.6 N. =49 from chart
H 1.96 Cut Slope (Siltstone/Claystone)
GROSS STABILITY ANALYSIS (JANBU'S CHART)
JOB NO.:
SD1163-00
JOATE:
August,1982 FIGURE:D-2
1
200
to(X
S 150
COCO
CO
« 100
3 JXCO
spa04 50
0
' SURFICAL
~— — -
--..: :rt
»
-*H
r-t-
-* --rr• • - t rm
^-—• - 'r4-
^^
0
STAB
: ::: r.'::: : '::
: H.f:4:Sf :rH
^iplfi
*• ; rr i -*-• t : - T*• f-r * • -r •»••»• r-*- •i ci'" T; t : :tzrr
• «fc£*i5 ^
H "--^ T ^ TT- T
1:|:::|: :i3
50
ILITY DAI
•_:. ::;TT J
:i:r:;^--.
T!.- ; t- :•;;
srtH^ltT-l
>-{jr -i:irtr
1 -, [ 1 t 1 | ' j :
. XL . . -J_|- 1 - ; 1
1
NORMAL
'A:
. j _
-^[-,':;'
^
•"frr
4-
•H-
00
SI
. * <
...q
— M
-t--
— i—
1?RE
Slope Ratio H) (2:1) ;
Total Unit Weight <
- • t
- T
: : r
^
| 1 t |
l i .
n
•44
ss
>6.(
i ijii
, -4_i
^A f.± rlrJ
ff- -I-T---I— H-f^j- 4J i i i ,
_i|j- -U-M- +li-r-
tl h-r-H-rr
j-— , — i t-j- .~;_i-..
-i— i- -(-i-rj- J---T
mma
150
(ii) psf
5 degn
JTt) 120 pcf
-:,:::-:::^,-
-r {-:: -.'::
PPSflllllhi -ill4- 4. -44— -rJ-L
4i... .-44- 4-f--'
sfcpB^;:-i
--H-- --f-H
. — . j. 44. J
|:: :::: S:
200
sea
:•. .
.Ut— .
i^- ,
4_i_! —
— L—
:-<-
——j-L-
::..;:;.:
— r-j- -H-A -
; t-T1*- T-*-"f
, j
— ri-i- 4 «--i
250
Bouyant Unit Weight <yv) 57.6 pcf
Depth of Seepage Plow (D)
FACTOR OF SAFETY (F.S.)
l« * Y DD
F <3 •=
Q\
3 . 0 feet
COS 2o£ - 138 psf S =
*~
S
D COS of sin <<
«
153 from above chart
t
1.06 Fill Slope (Remolded
Siltstone)
SURFICAL STABILITY ANALYSIS
JOB NOu IDATE:SD1163-00 | August, 1982 FIQURE:D-3
2.5
W
w
en
fa 1-5
0
o
1.0
0.5
SURFICI
'." .1
- i—
+— j
0
AL ST
. - l
.::!-:•:
- . i
_; : • " : . ' u
i ' i 'i . • j
,-; i , i.H
-j — _
^
•i-H-i
4-1. : *
AB:
• -4
-j — -E
;i* rr
r— 4:
,rr i.j.1 • i \ t
ELI
— r.... I .
kr*!•—
'1— r
fl-+~
•*-H"*
•t [ '-r
3*t
TH+-
~" ITT
-Lf4~
1
TY
Slope Ratio (»*)
. i i i
-Sr
— — f-
n
.jili.
4-T"
DE
DA
• — i
.. .. ;. .
...,.,..
•••l--.-
"FF
PN
Ls
H
rirr
•i-tr
PTI
TA
2.5:
• •
•trr
5:
J
S
s
_ ~j
1
»»
1
\,
IP
f-r
3
-H-
LjJ.
0
Total Unit Weight ( Yr )
. . \
' • | - -•
rrrrHT^
... .)...,_.
rftrt -pH-
-i-i.-'- : -L _L_.^-r<-. ^p—
iTjx,'i i .^
jlijl! i:ftfrfcir
itt:^:^
*p-rTTH-
2
F SEE
2:1
. :]•- -
4-TtC«,*.t-l....r. i.
1.1-1
-*-^rr,.j ...»
-^
PA<
1.
fc:
^i j i ;
i ! ^^
-^^.i-,-i
•K^
5E
5:
:::j-;
; • ; r • •
+4+--
ta
ar*-Lr "T1
44 =trf4-J
++rj---
3
(fee
1
r ; •;:
• ;
it
ttfFff
i i i • •-i-t- TJ-«-
•H 5^;
t -T-
^t^
i 4r-H" ; :4 *•
!t)
.:.:
•4-t-1--ttf
::r
^£
.!'...!-•!.
.1 t . . -
-f~ — ^
-I--H — -
1, '' . ,
• . '
4
• • i
i
- - 1
i ; i .
J-^T
"!~H —
' ::
*
F
-y-LJ-
J-.
120 pcf
Soil Type Remolded Siltstone
FACTOR OF
F.S. =
F.S. =
F.S. =
F.S. =
SAFETY (F.S.) :
2.41
1.59
1.27
1.13
(2.5:1)
SURFICIAL
JOB NOu
SD1163-00
1.98
1.32
1.06
0.93
(2:1)
1.59 (D = 1
1.08 (D = 2
0.86 (D = 3
0.75 (D = 4
(1.5:1)
foot)
feet)
feet)
feet)
STABILITY ANALYSIS: SUMMARY
IDATE:August, 1982 FIGURE:D-4
APPENDIX E
STANDARD GUIDELINES FOR GRADING PROJECTS
TABLE OF CONTENTS
1. GENERAL 1
2. DEFINITION OF TERMS 1
3. OBLIGATIONS OF PARTIES 5
4. SITE PREPARATION 5
5. SITE PROTECTION 6
6. EXCAVATIONS 8
6.1 UNSUITABLE MATERIALS 8
6.2 CUT SLOPES 8
6.3 PAD AREAS 9
7. COMPACTED FILL 9
7.1 PLACEMENT 10
7.2 MOISTURE . . 11
7.3 FILL MATERIAL 12
7.4 FILL SLOPES • 14
7.5 OFF-SITE FILL 16
8. DRAINAGE 16
9. STAKING 17
10. SLOPE MAINTENANCE 17
10.1 LANDSCAPE PLANTS 17
10.2 IRRIGATION 17
10.3 MAINTENANCE 18
10.4 REPAIRS 18
11. TRENCH BACKFILL 19
12. STATUS OF GRADING 20
STANDARD GUIDELINES FOR GRADING PROJECTS
1. GENERAL
1.1 The guidelines contained herein and the standard
details attached hereto represent this firm's stan-
dard recommendations for grading and other associated
operations on construction projects. These guide-
lines should be considered a portion of the project
specifications.
1.2 All plates attached hereto shall be considered as
part of these guidelines.
1.3 The Contractor should not vary from these guidelines
without prior recommendation by the Geotechnical Con-
sultant and the approval of the Client or his auth-
orized representative. Recommendation by the Geo-
technical Consultant and/or Client should not be
considered to preclude requirements for approval by
the controlling agency prior to the execution of any
changes.
1.4 These Standard Grading Guidelines and Standard De-
tails may be modified and/or superseded by recommen-
dations contained in the text of the preliminary
geotechnical report and/or subsequent reports.
1.5 If disputes arise out of the interpretation of these
grading guidelines or standard details, the Geotech-
nical Consultant shall provide the governing inter-
pretation.
2. DEFINITIONS OF TERMS
2.1 ALLUVIUM - unconsolidated detrital deposits resulting
from flow of water, including sediments deposited in
river beds, canyons, flood plains, lakes, fans at the
foot of slopes and estuaries.
2.2 AS-GRADED (AS-BUILT) - the surface and subsurface con-
ditions at completion of grading.
2.3 BACKCUT - a temporary construction slope at the rear
of "earth retaining structures such as buttresses,
shear keys, stabilization fills or retaining walls.
2.4 BACKDRAIN - generally a pipe and gravel or similar
drainage system placed behind earth retaining struc-
tures such as buttresses, stabilization fills and
retaining walls.
Page Two
2.5 BEDROCK - a more or less solid, relatively undis-
turbed rock in place either at the surface or be-
neath superficial deposits of soil.
2.6 BENCH - a relatively level step and near vertical
rise excavated into sloping ground on which fill is
to be placed.
2.7 BORROW (fmpbrt) - any fill material hauled to the
project site from off-site areas.
2.8 BUTTRESS FILL - a fill mass, the configuration of
which is designed by engineering calculations to
retain slope conditions containing adverse geologic
features. A buttress is generally specified by min-
imum key width and depth and by maximum backcut angle.
A buttress normally contains a backdrainage system.
2.9 CIVIL ENGINEER - the Registered Civil Engineer or
consulting firm responsible for preparation of the
grading plans, surveying and verifying as-graded
topographic conditions.
2.10 CLIENT - the Developer or his authorized representa-
tive who is chiefly in charge of the project. He
shall have the responsibility of reviewing the find-
ings and recommendations made by the Geotechnical
Consultant and shall authorize the Contractor and/or
other consultants to perform work and/or provide
services.
2.11 COLLUVIUM - generally loose deposits usually found
near the base of slopes and brought there chiefly by
gravity through slow continuous downhill creep (also
see Slope Wash).
2.12 COMPACTION - is the densification of a fill by mech-
anical means.
2.13 CONTRACTOR - a person or company under contract or
otherwise retained by the Client to perform demoli-
tion, grading and other site improvements.
2.14 DEBRIS - all products of clearing, grubbing, demoli-
tion, contaminated soil material unsuitable for reuse
as compacted fill and/or any other material so desig-
nated by the Geotechnical Consultant.
2.15 ENGINEERING GEOLOGIST - a Geologist holding a valid
certificate of registration in the specialty of
Engineering Geology.
Page Three
2.16 ENGINEERED FILL - a fill of which the Geotechnical
Consultant or his representative, during grading,
has made sufficient tests to enable him to conclude
that the fill has been placed in substantial com-
pliance with the recommendations of the Geotechnical
Consultant and the governing agency requirements.
2.17 EROSION - the wearing away of the ground surface as
a result of the movement of wind, water and/or ice.
2.18 EXCAVATION - the mechanical removal of earth materials.
2.19 EXISTING GRADE - the ground surface configuration
prior to grading.
2.20 FILL - any deposits of soil, rock, soil-rock blends
or other similar materials placed by man.
2.21 FINISH GRADE - the ground surface configuration at
which time the surface elevations conform to the
approved plan.
2.22 GEOFABRIC - any engineering textile utilized in geo-
technical applications including subgrade stabiliza-
tion and filtering.
2.23 GEOLOGIST - a representative of the Geotechnical Con-
sultant educated and trained in the field of geology.
2.24 GEOTECHNICAL CONSULTANT - the Geotechnical Engineering
and Engineering Geology consulting firm retained to
provide technical services for the project. For the
purpose of these specifications, observations by the
Geotechnical Consultant include observations by the
Soil Engineer, Geotechnical Engineer, Engineering
Geologist and those performed by persons employed by
and responsible to the Geotechnical Consultants.
2.25 GEOTECHNICAL ENGINEER - a licensed Civil Engineer who
applies scientific methods, engineering principles and
professional experience to the acquisition, interpre-
tation and use of knowledge of materials of the earth's
crust for the evaluation of engineering problems. Geo-
technical Engineering encompasses many of the engi-
neering aspects of soil mechanics, rock mechanics,
geology, geophysics, hydrology and related sciences.
2.26 GRADING - any operation consisting of excavation,
filling or combinations thereof and associated opera-
tions.
2.27 LANDSLIDE DEBRIS - material, generally porous and of
low density, produced from instability of natural or
man-made slopes.
2.28 MAXIMUM DENSITY - standard laboratory test for maximum
dry unit weight. Unless otherwise specified, the
maximum rirv unit wpiahi-. shall h*» rl (=1- fir-mi nor? in
Page Four
2.29 OPTIMUM MOISTURE - test moisture content at the
maximum density.
2.30 RELATIVE COMPACTION - the degree of compaction
(expressed as a percentage) of dry unit weight of
a material as compared to the maximum dry unit weight
of the material.
2.31 ROUGH GRADE - the ground surface configuration at which
time the surface elevations approximately conform to
the approved plan.
2.32 SITE - the particular parcel of land where grading
is being performed.
2.33 SHEAR KEY - similar to buttress, however, it is gen-
erally constructed by excavating a slot within a
natural slope in order to stabilize the upper por-
tion of the slope without grading encroaching into
the lower portion of the slope.
2.34 SLOPE - is an inclined ground surface the steepness
of which is generally specified as a ratio of hori-
zontal: vertical (e.g.,2:l).
2.35 SLOPE WASH - soil and/or rock material that has been
transported down a slope by mass wasting assisted by
runoff water not confined by channels (also see
Colluvium).
2.36 SOIL - naturally occurring deposits of sand, silt,
clay, etc. or combinations thereof.
2.37 SOIL ENGINEER - licensed Civil Engineer experienced
in soil mechanics (also see Geotechnical Engineer).
2.38 STABILIZATION FILL - a fill mass, the configuration
of which is typically related to slope height and is
specified by the standards of practice for enhancing
the stability of locally adverse conditions. A sta-
bilization fill is normally specified by minimum key
width and depth and by maximum backcut angle. A
stabilization fill may or may not have a backdrainage
system specified.
2. 39 | SUBDRAIN - generally a pipe and gravel or similar
drainage system placed beneath a fill in the align-
ment of canyons or former drainage channels.
2.40 SLOUGH - loose, noncompacted fill material generated
during grading operations.
2.41 TAILINGS - nonengineered fill which accumulates on
or adjacent to equipment haul-roads.
2.42 TERRACE - relatively level step constructed in the
face of a graded slope surface for drainage control
Page Five
2.43 TOPSOIL - the presumably fertile upper zone of soil
which is usually darker in color and loose.
2.44 WINDROW - a string of large rock buried within en-
gineered fill in accordance with guidelines set forth
by the Geotechnical Consultant.
3. OBLIGATIONS OF PARTIES
3.1 The Geotechnical Consultant should provide observa-
tion and testing services and should make evalua-
tions in order to advise the Client on geotechnical
matters. The Geotechnical Consultant should report
his findings and recommendations to the Client or
his authorized representative.
3.2 The Client should be chiefly responsible for all
aspects of the project. He or his authorized rep-
resentative has the responsibility of reviewing the
findings and recommendations of the Geotechnical
Consultant. He shall authorize or cause to have
authorized the Contractor and/or other consultants
to perform work and/or provide services. During
grading the Client or his authorized representative
should remain on-site or should remain reasonably
accessible to all concerned parties in order to make
decisions necessary to maintain the flow of the
project.
3.3 The Contractor should be responsible for the safety
of the project and satisfactory completion of all
grading and other associated operations on construc-
tion projects, including, but not limited to, earth
work in accordance with the project plans, specifi-
cations and controlling agency requirements. During
grading^ the Contractor or his authorized represen-
tative should remain on-site. Overnight and on days
off, the Contractor should remain accessible.
4. SITE PREPARATION
4.1 The Client, prior to any site preparation or grading,
should arrange and attend a meeting among the Grading
Contractor, the Design Engineer, the Geotechnical Con-
sultant, representatives of the appropriate governing
authorities as well as any other concerned parties.
All parties should be given at least 48 hours notice.
4.2 Clearing and grubbing should consist of the removal of
vegetation such as brush, grass, woods, stumps, trees,
roots of trees and otherwise deleterious natural mater-
ials from the areas to be graded. Clearing and grub-
bing should extend to the outside of all proposed
excavation and fill areas.
Page Six
4.3 Demolition should include removal of buildings,
structures, foundations, reservoirs, utilities (in-
cluding underground pipelines, septic tanks, leach
fields, seepage pits, cisterns, mining shafts, tun-
nels, etc.) and other man-made surface and sub-
surface improvements from the areas to be graded.
Demolition of utilities should include proper cap-
ping and/or rerouting pipelines at the project per-
imeter ana cutoff and capping of wells in accordance
with the requirements of the governing authorities
and the recommendations of the Geotechnical Consul-
tant at the time of demolition.
4.4 Trees, plants or man-made improvements not planned
to be removed or demolished should be protected by
the Contractor from damage or injury.
4.5 Debris generated during clearing, grubbing and/or
demolition operations should be wasted from areas
to be graded and disposed off-site. Clearing, grub-
bing and demolition operations should be performed
under the observation of the Geotechnical Consultant.
4.6 The Client or Contractor should obtain the required
approvals from the controlling authorities for the
project prior, during and/or after demolition, site
preparation and removals, etc. The appropriate ap-
provals should be obtained prior to proceeding with
grading operations.
5. SITE PROTECTION
5.1 Protection of the site during the period of grading
should be the responsibility of the Contractor. Un-
less other provisions are made in writing and agreed
upon among the concerned parties, completion of a
portion of the project should not be considered to
preclude that portion or adjacent areas from the
requirements for site protection until such time as
the entire project is complete as identified by the
Geotechnical Consultant, the Client and the regu-
lating agencies.
5.2 The Contractor should be responsible for the stability
of all temporary excavations. Recommendations by the
Geotechnical Consultant pertaining to temporary exca-
vations (e.g., backcuts) are made in consideration of
stability of the completed project and, therefore,
should not be considered to preclude the responsi-
bilities of the Contractor. Recommendations by the
Geotechnical Consultant should not be considered to
preclude more restrictive requirements by the regu-
lating agencies.
Page Seven
5.3 Precautions should be taken during the performance
of site clearing, excavations and grading to protect
the work site from flooding, ponding or inundation by
poor or improper surface drainage. Temporary provi-
sions should be made during the rainy season to ade-
quately direct surface drainage away from and off the
work site. Where low areas cannot be avoided, pumps
should be v*»pt on hand to continually remove water
during periods of rainfall.
5.4 During periods of rainfall, plastic sheeting should
be kept reasonably accessible to prevent unprotected
slopes from becoming saturated. Where necessary dur-
ing periods of rainfall, the Contractor should install
checkdams, desilting basins, rip-rap, sand bags or other
devices or methods necessary to control erosion and
provide safe conditions.
5.5 During periods of rainfall, the Geotechnical Consultant
should be kept informed by the Contractor as to the
nature of remedial or preventative work being performed
(e.g., pumping, placement of sandbags or plastic sheet-
ing, other labor, dozing, etc.).
5.6 Following periods of rainfall, the Contractor should
contact the Geotechnical Consultant and arrange a walk-
over of the site in order to visually assess rain re-
lated damage. The Geotechnical Consultant may also
recommend excavations and testing in order to aid in
his assessments. At the request of the Geotechnical
Consultant, the Contractor shall make excavations in
order to evaluate the extent of rain related-damage.
5.7 Rain-related damage should be considered to include,
but may not be limited to, erosion, silting, saturation,
swelling, structural distress and other adverse condi-
tions identified by the Geotechnical Consultant. Soil
adversely affected should be classified as Unsuitable
Materials and should be subject to overexcavation and
replacement with compacted fill or other remedial grad-
ing as recommended by the Geotechnical Consultant.
5.8 Relatively level areas, where saturated soils and/or
erosion gullies exist to depths of greater than 1.0
foot, should be overexcavated to unaffected, compe-
tent material. Where less than 1.0 foot in depth, un-
suitable materials may be processed in-place to achieve
near-optimum moisture conditions, then thoroughly re-
compacted in accordance with the applicable specifica-
tions. If the desired results are not achieved, the
affected materials should be overexcavated, then re-
placed in accordance with the applicable specifications.
Page Eight
5.9 In slope areas, where saturated soil and/or erosion
gullies exist to depths of greater than 1.0 foot,
they should be overexcavated and replaced as compacted
fill in accordance with the applicable specifications.
Where affected materials exist to depths of 1.0 foot
or less below proposed finished grade, remedial grad-
ing by moisture conditioning in-place, followed by
thorough recompaction in accordance with the applic-
able gradffag" guidelines herein may be attempted. If
the desired results are not achieved, all affected
materials should be overexcavated and replaced as
compacted fill in accordance with the slope repair
recommendations herein. As field conditions dictate,
other slope repair procedures may be recommended by
the Geotechnical Consultant.
6. EXCAVATIONS
6.1 UNSUITABLE MATERIALS
6.1.1 Materials which are unsuitable should be exca-
vated under observation and recommendations of
the Geotechnical Consultant. Unsuitable mater-
ials include, but may not be limited to, dry,
loose, soft, wet, organic compressible natural
soils and fractured, weathered, soft bedrock
and nonengineered or otherwise deleterious
fill materials.
6.1.2 Material identified by the Geotechnical Consul-
tant as unsatisfactory due to it's moisture
conditions should be overexcavated, watered or
dried, as needed, and thoroughly blended to a
uniform near optimum moisture condition (as per
guidelines reference 7.2.1) prior to placement
as compacted fill.
6.2 CUT SLOPES
6.2.1 Unless otherwise recommended by the Geotechnical
Consultant and approved by the regulating agen-
cies, permanent cut slopes should not be steeper
than 2:1 (horizontal:vertical).
6.2.2 If excavations for cut elopes expose loose, co-
hesionless, significantly fractured or otherwise
unsuitable material, overexcavation and replace-
ment of the unsuitable materials with a compacted
stabilization fill should be accomplished as
"~* recommended by the Geotechnical Consultant.
Unless otherwise specified by the Geotechncial
Consultant, stabilization fill construction
should conform to the requirements of the Stan-
dard Details.
Page Nine
6.2.3 The Geotechnical Consultant should review cut
slopes during excavation. The Geotechnical
Consultant should be notified by the contractor
prior to beginning slope excavations.
6.2.4 If, during the course of grading, adverse or
potentially adverse geotechnical conditions are
encountered which were not anticipated in the
preliminary report, the Geotechnical Consultant
should explore, analyze and make recommenda-
tions to treat these problems.
6.2.5 When cut slopes are made in the direction of
the prevailing drainage, a non-erodible diver-
sion swale (brow ditch) should be provided at
the top-of-cut.
6.3 PAD AREAS
6.3.1 All lot pad areas, including side yard terraces,
above stabilization fills or buttresses should
be overexcavated to provide for a minimum of
3 feet (refer to Standard Details) of compacted
fill over the entire pad area. Pad areas with
both fill and cut materials exposed and pad
areas containing both very shallow (less than
3 feet) and deeper fill should be overexcavated
to provide for a uniform compacted fill blanket
with a minimum of 3 feet in thickness (refer to
Standard Details). Cut areas exposing signi-
ficantly varying material types should also be
overexcavated to provide for at least a 3-foot
thick compacted fill blanket. Geotechnical
conditions may require greater depth of over-
excavation. The actual depth should be de-
lineated by the Geotechnical Consultant during
grading.
6.3.2 For pad areas created above cut or natural
slopes, positive drainage should be established
away from the top-of-slope. This may be accom-
plished utilizing a berm and/or an appropriate
pad gradient. A gradient in soil areas away
from the top-of-slopes of 2 percent or greater
is recommended.
7. COMPACTED FILL
All fill^materials should be compacted as specified below
or by other methods specifically recommended by the Geotech-
nical Consultant. Unless otherwise specified, the minimum
degree of compaction (relative compaction) should be 90
percent of the laboratory maximum density.
Page Ten
7.1 PLACEMENT
7.1.1 Prior to placement of compacted fill, the Con-
tractor should request a review by the Geotech-
nical Consultant of the exposed ground surface.
Unless otherwise recommended, the exposed ground
surface should then be scarified (six inches mini-
mum) , watered or dried as needed, thoroughly
bfended to achieve near optimum moisture condi-
tions, then thoroughly compacted to a minimum
of 90 percent of the maximum density. The re-
view by the Geotechnical Consultant should not
be considered to preclude requirement of inspec-
tion and approval by the governing agency.
7.1.2 Compacted fill should be placed in thin hori-
zontal lifts not exceeding eight inches in loose
thickness prior to compaction. Each lift
should be watered or dried as needed, thoroughly
blended to achieve near optimum moisture condi-
tions then thoroughly compacted by mechanical
methods to a minimum of 90 percent of laboratory
maximum dry density. Each lift should be treated
in a like manner until the desired finished
grades are achieved.
7.1.3 The Contractor should have suitable and suffi-
cient mechanical compaction equipment and water-
ing apparatus on the job site to handle the
amount of fill being placed in consideration
of moisture retention properties of the mater-
ials. If necessary, excavation equipment should
be "shut down" temporarily in order to permit
proper compaction of fills. Earth moving equip-
ment should only be considered a supplement and
not substituted for conventional compaction
equipment.
7.1.4 When placing fill in horizontal lifts adjacent
to areas sloping steeper than 5:1 (horizontal:
vertical), horizontal keys and vertical benches
should be excavated into the adjacent slope area.
Keying and benching should be sufficient to pro-
vide at least six-foot wide benches and a mini-
mum of four feet of vertical bench height within
the firm natural ground, firm bedrock or engi-
neered compacted fill. No compacted fill should
be placed in an area subsequent to keying and
benching until the area has been reviewed by
the Geotechnical Consultant. Material generated
by the benching operation should be moved suf-
ficiently away from the bench area to allow for
the recommended review of the horizontal bench
prior to placement of fill. Typical keying and
benching details have been included within the
accompanying Standard Details.
Page Eleven
7.1.5 Within a single fill area where grading proce-
dures dictate two or more separate fills, tem-
porary slopes (false slopes) may be created.
When placing fill adjacent to a false slope,
benching should be conducted in the same man-
ner as above described. At least a 3-foot
vertical bench should be established within
the firm core of adjacent approved compacted
fiat!— prior to placement of additional fill.
Benching should proceed in at least 3-foot
vertical increments until the desired finished
grades are achieved.
7.1.6 Fill should be tested for compliance with the
recommended relative compaction and moisture
conditions. Field density testing should con-
form to ASTM Method of Test D 1556-64, D 2922-78
and/or D 2937-71. Tests should be provided for
about every two vertical feet or 1,000 cubic
yards of fill placed. Actual test interval
may vary as field conditions dictate. Fill
found not to be in conformance with the grad-
ing recommendations should be removed or other-
wise handled as recommended by the Geotechnical
Consultant.
7.1.7 The Contractor should assist the Geotechnical
Consultant and/or his representative by digging
test pits for removal determinations and/or for
testing compacted fill.
7.1.8 As recommended by the Geotechnical Consultant,
the Contractor should "shut down" or remove
grading equipment from an area being tested.
7.1.9 The Geotechnical Consultant should maintain a
plan with estimated locations of field tests.
Unless the client provides for actual surveying
of test locations, the estimated locations by
the Geotechnical Consultant should only be con-
sidered rough estimates and should not be uti-
lized for the purpose of preparing cross sec-
tions showing test locations or in any case for
the purpose of after-the-fact evaluating of the
sequence of fill placement.
7.2 MOISTURE
7.2.1 For field testing purposes, "near optimum" mois-
ture will vary with material type and other
factors including compaction procedure. "Near
optimum" may be specifically recommended in
Preliminary Investigation Reports and/or may
be evaluated during grading.
Page Twelve
7.2.2 Prior to placement of additional compacted
fill following an overnight or other grading
delay/ the exposed surface or previously com-
pacted fill should be processed by scarifica-
tion, watered or dried as needed, thoroughly
blended to near-optimum moisture conditions,
then recompacted to a minimum of 90 percent
ofcaJLaboratory maximum dry density. Where wet
or other dry or other unsuitable materials
exist to depths of greater than one foot, the
unsuitable materials should be overexcavated.
7.2.3 Following a period of flooding, rainfall or
overwatering by other means, no additional
fill should be placed until damage assess-
ments have been made and remedial grading
performed as described under Section 5.6
herein.
7. 3 FILL MATERIAL
7.3.1 Excavated on-site materials which are accept-
able to the Geotechnical consultant may be
utilized as compacted fill, provided trash,
vegetation and other deleterious materials
are removed prior to placement.
7.3.2 Where import materials are required for use .
on-site, the Geotechnical Consultant should be
notified at least 72 hours in advance of im-
porting, in order to sample and test materials
from proposed borrow sites. No import mater-
ials should be delivered for use on-site with-
out prior sampling and testing by GJeotechnical
Consultant.
7.3.3 Where oversized rock or similar irreducible ma-
terial is generated during grading, it is rec-
ommended, where practical, to waste such mater-
ial off-site or on-site in areas designated as
"nonstructural rock disposal areas". Rock
placed in disposal areas should be placed with
sufficient fines to fill voids. The rock should
be compacted in lifts to an unyielding condi-
tion. The disposal area should be covered with
at least three feet of compacted fill which is
free of oversized material. The upper three
feet should be placed in accordance with the
guidelines for compacted fill herein.
Page Thirteen
7.3.4 Rocks 12 inches in maximum dimension and smal-
ler may be utilized within the compacted fill,
provided they are placed in such a manner that
nesting of the rock is avoided. Fill should
be placed and thoroughly compacted over and
around all rock. The amount of rock should
not exceed 40 percent by dry weight passing
thg 3/4-inch sieve size. The 12-inch and 40
percent recommendations herein may vary as
field conditions dictate.
7.3.5 During the course of grading operations, rocks
or similar irreducible materials greater than
12 inches maximum dimension (oversized material),
may be generated. These rocks should not be
placed within the compacted fill unless placed
as recommended by the Geotechnical Consultant.
7.3.6 Where rocks or similar irreducible materials of
greater than 12 inches but less than four feet of
maximum dimension are generated during grading,
or otherwise desired to be placed within an
engineered fill, special handling in accord-
ance with the accompanying Standard Details is
recommended. Rocks greater than four feet should
be broken down or disposed off-site. Rocks
up to four feet maximum dimension should be placed
below the upper 10 feet of any fill and should
not be closer than 20 feet to any slope face.
These recommendations could vary as locations
of improvements dictate. Where practical, over-
sized material should not be placed below areas
where structures or deep utilities are proposed.
Oversized material should be placed in windrows
on a clean, overexcavated or unyielding com-
pacted fill or firm natural ground surface.
Select native or imported granular soil (S.E. 30
or higher) should be placed and thoroughly
flooded over and around all windrowed rock, such
that voids are filled. Windrows of oversized
material should be staggered so that successive
strata of oversized material are not in the
same vertical plane.
7.3.7 It may be possible to dispose of individual
larger rock as field conditions dictate and as
recommended by the Geotechnical Consultant at
the time of placement.
7.3.8 Material that is considered unsuitable by the
Geotechnical Consultant should not be utilized
in the compacted fill.
Page Fourteen
7.3.9 During grading operations, placing and mixing
the materials from the cut and/or borrow areas
may result in soil mixtures which possess
unique physical properties. Testing may be
required of samples obtained directly from the
fill areas in order to verify conformance with
the specifications. Processing of these ad-
d^£ional samples may take two or more working
days. The Contractor may elect to move the
operation to other areas within the project,
or may continue placing compacted fill pending
laboratory and field test results. Should he
elect the second alternative, fill placed is
done so at the Contractor's risk.
7.3.10 Any fill placed in areas not previously re-
viewed and evaluated by the Geotechnical Con-
sultant, and/or in other areas, without prior
notification to the Geotechnical Consultant may
require removal and recompaction at the Con-
tractor's expense. Determination of overex-
cavations should be made upon review of field
conditions by the Geotechnical Consultant.
7.4 FILL SLOPES
7.4.1 Unless otherwise recommended by the Geotechnical
Consultant and approved by the regulating agen-
cies, permanent fill slopes should not be
steeper than 2:1 (horizontal:vertical).
7.4.2 Except as specifically recommended otherwise
or as otherwise provided for in these grading
guidelines (Reference 7.4.3), compacted fill
slopes should be overbuilt and cut back to
grade, exposing the firm, compacted fill inner
core. The actual amount of overbuilding may
vary as field conditions dictate. If the de-
sired results are not achieved, the existing
slopes should be overexcavated and reconstructed
under the guidelines of the Geotechnical Consul-
tant. The degree of overbuilding shall be in-
creased until the desired compacted slope sur-
face condition is achieved. Care should be
taken by the Contractor to provide thorough
mechanical compaction to the outer edge of the
overbuilt slope surface.
7.4^3 Although no construction procedure produces a
slope free from risk of future movement, over-
filling and cutting back of slope to a compacted
inner core is, given no other constraints, the
most desirable procedure. Other constraints,
however, must often be considered. These con-
straints may include property line situations,
Page Fifteen
access, the critical nature of the development
and cost. Where such constraints are identi-
fied, slope face compaction may be attempted
by conventional construction procedures includ-
ing backrolling techniques upon specific recom-
mendation by the Geotechnical Consultant.
Asa_second best alternative for slopes of 2:1
(horizontal:vertical) or flatter, slope con-
struction may be attempted as outlined herein.
Fill placement should proceed in thin lifts, i.e.,
six to eight inch loose thickness). Each lift
should be moisture conditioned and thoroughly
compacted. The desired moisture condition
should be maintained and/or re-established,
where necessary, during the period between
successive lifts. Selected lifts should be
tested to ascertain that desired compaction is
being achieved. Care should be taken to ex-
tend compactive effort to the outer edge of
the slope. Each lift should extend horizontally
to the desired finished slope surface or more
as needed to ultimately establish desired grades.
Grade during construction should not be allowed
to roll off at the edge of the slope. It may
be helpful to elevate slightly the outer edge
of the slope. Slough resulting from the place-
ment of individual lifts should not be allowed
to drift down over previous lifts. At intervals
not exceeding four feet in vertical slope height
or the capability of available equipment, which-
ever is less, fill slopes should be thoroughly
backrolled utilizing a conventional sheepsfoot-
type roller. Care should be taken to maintain
the desired moisture conditions and/or re-
establishing same as needed prior to backrolling.
Upon achieving final grade, the slopes should
again be moisture conditioned and thoroughly
backrolled. The use of a side-boom roller will
probably be necessary and vibratory methods are
strongly recommended. Without delay, so as to
avoid (if possible) further moisture conditioning,
the slopes should then be grid-rolled to achieve
a relatively smooth surface and uniformly com-
pact condition.
In order to monitor slope construction proce-
dures, moisture and density tests will be taken
at regular intervals. Failure to achieve the
desired results will likely result in a recom-
mendation by the Geotechnical consultant to
Page Sixteen
overexcavate the slope surfaces followed by
reconstruction of the slopes utilizing over-
filling and cutting back procedures and/or
further attempt at the conventional back-
rolling approach. Other recommendaitons may
also be provided which would be commensurate
with field conditions.
7.4.4 Wllere placement of fill above a natural slope
or above a cut slope is proposed, the fill
slope configuration as presented in the ac-
companying Standard Details should be adopted.
7.4.5 For pad areas above fill slopes, positive drain-
age should be established away from the top-
of-slope. This may be accomplished utilizing
a berm and pad gradients of at least 2 percent
in soil areas.
7.5 OFF-SITE FILL
7.5.1 Off-site fill should be treated in the same
manner as recommended in these specifications
for site preparation, excavation, drains, com-
paction, etc.
7.5.2 Off-site canyon fill should be placed in prep-
aration for future additional fill, as shown
in the accompanying Standard Details.
7.5.3 Off-site fill subdrains temporarily terminated
(up canyon) should be surveyed for future re-
location and connection.
8. DRAINAGE
8.1 Canyon subdrain systems specified by the Geotechnical
Consultant should be installed in accordance with the
Standard Details.
8.2 Typical subdrains for compacted fill buttresses, slope
stabilizations.or sidehill masses, should be installed
in accordance with the specifications of the accompany-
ing Standard Details.
8.3 Roof, pad and slope drainage should be directed away
from slopes and areas of structures to suitable dis-
posal areas via non-erodible devices (i.e., gutters,
downspouts, concrete swales).
8.4 For drainage over soil areas immediately away from
structures, (Le. , within four feet) a minimum of 4 percent
gradient should be maintained. Pad drainage of at
least 2 percent should be maintained over soil areas.
Pad drainage may be reduced to at least 1 percent for
Page Seventeen
projects where no slopes exist, either natural or man-
made, of greater than 10 feet in height and where no
slopes are planned, either natural or man-made,
steeper than 2:1 (horizontal:vertical slope ratio).
8.5 Drainage patterns established at the time of fine grad-
ing should be maintained throughout the life of the
project, property owners should be made aware that
altering drainage patterns can be detrimental to slope
stability and foundation performance.
9. STAKING
9.1 In all fill areas, the fill should be compacted prior
to the placement of the stakes. This particularly is
important on fill slopes. Slope stakes should not be
placed until the slope is thoroughly compacted (back-
rolled) . If stakes must be placed prior to the com-
pletion of compaction procedures, it must be recognized
that they will be removed and/or demolished at such
time as compaction procedures resume.
9.2 In order to allow for remedial grading operations,
which could include overexcavations or slope stabili-
zation, appropriate staking offsets should be provided.
For finished slope and stabilization backcut areas, we
recommend at least a 10-foot setback from proposed
toes and tops-of-cut.
10. SLOPE MAINTENANCE
10.1 LANDSCAPE PLANTS
In order to enhance surficial slope stability, slope
planting should be accomplished at the completion of
grading. Slope planting should consist of deep-rooting
vegetation requiring little watering. Plants native to
the southern California area and plants relative to
native plants are generally desirable. Plants native
to other semi-arid and arid areas may also be appro-
priate. A Landscape Architect would be the best party
to consult regarding actual types of plants and plant-
ing configuration.
10.2 IRRIGATION
10.2.1 Irrigation pipes should be anchored to slope
faces, not placed in trenches excavated into
slope faces.
10.2.2 Slope irrigation should be minimized. If auto-
matic timing devices are utilized on irrigation
systems, provisions should be made for inter-
rupting normal irrigation during periods of
rainfall.
Page Eighteen
10.2.3 Though not a requirement, consideration should
be given to the installation of near-surface
moisture monitoring control devices. Such de-
vices can aid in the maintenance of relatively
uniform and reasonably constant moisture
conditions.
10.2.4 Property owners should be made aware that over-
watering of slopes is detrimental to slope
stability.
10.3 MAINTENANCE
10.3.1 Periodic inspections of landscaped slope areas
should be planned and appropriate measures
should be taken to control weeds and enhance
growth of the landscape plants. Some areas
may require occasional replanting and/or
reseeding.
10.3.2 Terrace drains and downdrains should be period-
ically inspected and maintained free of debris.
Damage to drainage improvements should be re-
paired immediately.
10.3.3 Property owners should be made aware that bur-
rowing animals can be detrimental to slope sta-
bility, A preventative program should be esta-
blished to control burrowing animals.
10.3.4 As a precautionary measure, plastic sheeting
should be readily available, or kept on hand,
to protect all slope areas from saturation by
periods of heavy or prolonged rainfall. This
measure is strongly recommended, beginning with
the period of time prior to landscape planting.
10.4 REPAIRS
10.4.1 If slope failures occur, the Geotechnical Con-
sultant should be contacted for a field review
of site conditions and development of recommen-
dations for evaluation and repair.
10.4.2 If slope failures occur as a result of exposure
to periods of heavy rainfall, the failure area
and currently unaffected areas should be covered
with plastic sheeting to protect against addi-
tional saturation.
10.4.3 In the accompanying Standard Details, appro-
priate repair procedures are illustrated for
superficial slope failures (i.e., occuring typi-
cally within the outer one foot to three feet±
of a slope face).
Page Nineteen
11. TRENCH BACKFILL
11.1 Utility trench backfill should, unless otherwise
recommended, be compacted by mechanical means. Unless
otherwise recommended, the degree of compaction should
be a minimum of 90 percent of the laboratory maximum
density.
11.2 As an alternative, granular material (sand equivalent
greater than 30) may be thoroughly jetted in-place.
Jetting should only be considered to apply to trenches
no greater than two feet in width and four feet in depth.
Following jetting operations, trench backfill should
be thoroughly mechanically compacted and/or wheel-
rolled from the surface.
11.3 Backfill of exterior and interior trenches extending
below a 1:1 projection from the outer edge of founda-
tions should be mechanically compacted to a minimum
of 90 percent of the laboratory maximum density.
11.4 Within slab areas, but outside the influence of foun-
dations, trenches up to one foot wide and two feet deep
may be backfilled with sand and consolidated by jet-
ting, flooding or by mechanical means. If on-site
materials are utilized, they should be wheel-rolled,
tamped or otherwise compacted to a firm condition.
For minor interior trenches, density testing may be
deleted or spot testing may be elected if deemed
necessary, based on review of backfill operations
during construction.
11.5 If utility contractors indicate that it is undesirable
to use compaction equipment in close proximity to a
buried conduit, the Contractor may elect the utiliza-
tion of light weight mechanical compaction equipment
and/or shading of the conduit with clean, granular
material, which should be thoroughly jetted in-place
above the conduit, prior to initiating mechanical com-
paction procedures. Other methods of utility trench
compaction may also be appropriate, upon review by the
Geotechnical Consultant at the time of construction.
11.6 In cases where clean granular materials are proposed
for use in lieu of native materials or where flooding
or jetting is proposed, the procedures should be con-
sidered subject to review by the Geotechnical
Consultant.
^-*- %
11.7 Clean granular backfill and/or bedding are not recom-
mended in slope areas unless provisions are made for
a drainage system to mitigate the potential build-up
of seepage forces.
Page Twenty
12. STATUS OF GRADING
Prior to proceeding with any grading operation, the Geotech-
nical Consultant should be notified at least two working days
in advance in order to schedule the necessary observation
and testing services.
12.1 Prior to any__significant expansion or cut back in the
grading operation, the Geotechnical Consultant should
be provided with adequate notice (i.e., two days) in
order to make appropriate adjustments in observation
and testing services.
12.2 Following completion of grading operations and/or be-
tween phases of a grading operation, the Geotechnical
Consultant should be provided with at least two working
days notice in advance of commencement of additional
grading operations.
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