HomeMy WebLinkAboutCT 73-29; Carrillo Estates; Soils Report; 1981-05-05GEOLOGIC INVESTIGATION UPDATE SOIL AND
CARRILLO ESTATES, CARLSBAD,
Prepared For
11300 Sorrento Valley Road Ponderosa Homes, Inc.
San Diego, California 92121
BLOC -CT 73-27
I' *i San Diego. Cal~lorn~a 92110
?A67 KurtzSlreel
714-224-2911
..
Telex 697-841
May 5, 1981 Project No. 51142W-UDO1
WoodwardlClyde Consultants
Ponderosa Homes, Inc.
11300 Sorrento Valley Road San Diego, California 92121
Attention: Mr. Ken Cook
UPDATE SOIL AND GEOLOGIC INVESTIGATION CARRILLO ESTATES, UNIT 2 CARLSBAD. CALIFORNIA
Gentlemen:
We are pleased to present the results of our update soil and geological investigation for the subject site. This study was performed in accordance with our agreement dated May 1, 1981. This report presents our conclusions and recommendations per- taining to the project as well as the results of our field investigation.
If you should have any questions concerning this report, please give us a call.
Very truly yours,
WOODWARD-CLYDE CONSULTANTS
Robert J. Dowlen C.E.G. 1011
RJD/RPW/RJD/mm
Attachments
(4) Ponderosa Homes, Inc. (4) Rick Engineering Company
Richard P. While R.E. 21992
Consulllng Engineers. Geoloq~sts
and Environmental Scientists
OHtceS In Other Prlnclpal Ci1:es
Project No. 511 4-UDO1 ", ' f il c
t 1,
I
TABLE-OF CONTENTS
.
d odward-Clyde Consultants
PURPOSE OF INVESTIGATION
BACKGROUND INFORMATION AND PROJECT DESCRIPTION
FIELD AND LABORATORY INVESTIGATION
SITE, SOIL AND GEOLOGIC CONDITIONS
Geologic Setting Site Conditions Subsurface Conditions
Structure and Faulting Landslides Ground Water
DISCUSSIONS, CONCLUSIONS, AND RECOMMENDATIONS
Potential Geologic Hazards
Faulting and Ground Breakage Liquefaction Landslides
RISK AND OTHER CONSIDERATIONS
FIGURE 1 - SITE PLAN AND GEOLOGIC MAP
APPENDIX A - FIELD INVESTIGATION
Page
1
2
3
3
3 3
4
4 4 5 5 5 5
5
6
6
6
6
6
7 7
7
8
10
11 13
13
A-1
ii
Project No. 51
1 I, 3,
I k.)
d adward-Clyde Consultants
TABLE OF CONTENTS (Continued)
TABLE A-1 - SUMMARY OF ENGINEERING SEISMOGRAPH TRAVERSES
FIGURE A-1 - KEY TO LOGS
FIGURES A-2 THROUGH A-4 - LOGS OF TEST BORINGS
APPENDIX B - SOIL INVESTIGATION FOR THE PROPOSED
CARILLO ESTATES, CARLSBAD, CALIFORNIA SEPTEMBER 6, 1973, PROJECT NO. 73-203
APPENDIX C - SLOPE STABILITY ANALYSIS
APPENDIX D - SPECIFICATIONS FOR CONTROLLED FILL
APPENDIX E - OVERSIZE ROCK PLACEMENT AREAS
Page
c-1
D-1
E-1
iii
6 Jdward-Clyde Consultants
UPDATE SOIL AND GEOLOGIC INVESTIGATION
CARRILLO ESTATES, UNIT 2
CARLSBAD, CALIFORNIA
This report presents the results of our update soil and
geological investigation for the proposed Carrillo Estates
Unit 2 residential subdivision. The site encompasses a pre-
viously graded site extending westerly from the intersection
of Flamenco Street and La Golondrina Street in the City of
Carlsbad, California (Fig. 1). The property is bordered on
the south and east by the previously developed Carrillo
Estates, Unit 1 subdivision.
PURPOSE OF INVESTIGATION
The purpose of our investigation is to assist Ponderosa
Homes, Inc., and their consultants in further development of
the site. Our report includes conclusions and recommendations
regarding:
0 Existing (current) surface soil conditions,
0 Potential geologic hazards,
0 General extent of existing fill soils,
0 Conditions of areas to receive fill,
0 Characteristics of proposed fill material,
0 Presence and effect of expansive soils,
0 Stability of proposed cut and fill slopes,
0 Grading and earthwork specifications,
0 Allowable soil bearing pressures, and
Types and depth of foundations. 0
I Project No. 511. c .d-UDOl I?
I. i.
The investigation also consisted of evaluating the rip-
pability characteristics of the rock material in probable cut
areas.
BACKGROUND INFORMATION AND PROJECT DESCRIPTION
For our study we have discussed the proposed project with
Mr. Ken Cook of Ponderosa Homes, Inc., and Mr. Mick Ratican of
Rick Engineering Company and we have been provided with
undated preliminary grading plans entitled "Carlsbad Tract
No. 73-29 (Carrillo Estates) Unit No. 2," prepared by Rick
Engineering Company (scale 1" = 30' ) .
In addition, we have reviewed the following reports and
photographs:
0 "Soil Investigation for the Proposed Carrillo
Estates, Carlsbad, California, prepared by Woodward-Gizenski & Associates, dated September 6, 1973.
0
by Cartwright Aerial Surveys for USDA, 1964. Stereographic aerial photographs, AXN Series, flown
We understand that the proposed project will include
grading the site into approximately 111 lots with connecting
roadways. In addition, a northwesterly extension of El Fuerte
Street is proposed in the canyon along the northern boundary
(Fig. 1). We understand that the proposed construction will
be limited to one- and two-story, wood frame and stucco resi-
dential structures, supported on continuous footings and
having concrete slab-on-grade floors.
The grading plans indicate that within the subdivision
proper, proposed cut and composite cut/fill slopes will have
maximum inclinations of 1-1/2 to 1 (horizontal to vertical)
and have heights of up to 15 feet. Also, cut and fill slopes
2
with maximum inclinations of 2 to 1 and maximum heights of
approximately 40 and 120 feet respectively, are proposed. Cut
slopes proposed along the El Fuerte Street alignment will have
maximum inclinations of 2 to 1 to heights of up to 65 feet.
FIELD AND LABORATORY INVESTIGATION
Our field investigation was conducted between Mary 3 and
April 16, 1981 and included making a visual reconnaissance of
existing surface conditions, drilling two bucket auger borings
and obtaining representative soil samples. Two shallow
refraction seismic traverses were also made in a suspected
rock cut. The borings were drilled to depths of 70 feet and
38 feet, and the seismic traverses were 100 feet in length The
locations of the test explorations and seismic traverses are
shown on Fig. 1.
A Key to Logs is presented in Appendix A as Fig. A-1.
Simplified logs of the test borings are presented in Appen-
dix A as Figs. A-2 through A-4. The descriptions on the logs
are based on field logs and on sample inspection. The results
and interpretation of the seismic traverses are presented on
Table A-1. Laboratory test data, including fill suitability
test results, are given in the aforementioned report which is
attached as Appendix B.
SITE, SOIL AND GEOLOGIC CONDITIONS
Geologic Setting
The site is in an area characterized by erosional rem-
nants of Tertiary age sedimentary deposits lying on an older,
irregular surface of Jurassic age metavolcanic rock.
Site Conditions
The site is located on a generally northwesterly trending
ridge, whose upper surface was significantly lowered by pre-
vious grading operations in the southern and central parts.
3
Project No. 511.. ( -d-UDOl
It 'I
" ,
k.:odward-Clyde Consultants
This grading has produced a generally flattened area, with cut
slopes ranging in inclination from 1-1/2 to 1 to 5 to 1 with
heights of up to approximately 26 feet. The area has subse-
quently been used extensively as a dumping area for oversize
rock, construction debris and end-dumped fill soils.
Vegetation ranges from a sparse growth of weeds in the
disturbed section to dense chaparral on the natural hillsides.
A concrete storm drain is present along the La Golondrina
Street easement from Unit 1. This drain turns northward
between Lots 144 and 145 and empties into the canyon.
Subsurface Conditions
The site is underlain by both compacted and undocumented
fill soils, surficial topsoils, Quaternary age alluvium, the
Eocene age Delmar Formation and the Jurassic age Santiago Peak
Volcanics. These units are described below; their areal
extent, with the exception of the undocumented fill soils and
the surficial topsoils, are approximately shown on Fig. 1.
The geologic map symbol for each unit is given after the
formal name for the unit.
Undocumented Fill (unmapped) - Undocumented fill soils,
consisting of variable soil types, cover much of the eastern
half of the site. These soils are mixed with variable amounts
of oversize rock, concrete, and asphalt. Most of the fill
remains piled in 2- to 4-foot high mounds although it has been
leveled in areas along the alignment of La Golondrina Street.
Compacted Fill (Qaf) - Fill soils were placed and com-
pacted on the site in conjunction with the grading of Carrillo
Estates, Unit 1 in March through July of 1977. Placement of
these soils was observed by personnel from our firm and com-
paction tests were taken. The data pertaining to this fill
are on file and will be included with the final report of
grading and compaction testing for the site.
4
- , Project No. 511 c . ,i-UDOl 1, ., Jdward-Clyde Consultants
Topsoils (unmapped) - A topsoil layer, composed of porous
silty sand to silty clay, is present on the natural hillside
on the site. We estimate these soils to range from 1 to
3 feet in thickness.
Alluvium (Qal) - Alluvial deposits are confined to the
natural drainage channels in the "open space" areas of the
site, and along the proposed extension of El Fuerte Street.
The alluvial materials consist generally of silty to clayey
sands with varying amounts of gravels. It is estimated that
these deposits are on the order of 10 feet in maximum
thickness.
Delmar Formation (Td) - The area of the lots to be devel-
oped is entirely underlain by dense silty to clayey sands of
the Delmar Formation. Zones of very cemented sand layers are
randomly present within the formation that may be encountered
during grading. These cemented layers were observed to be up
to approximately 3 feet in thickness.
A review of the previous and present test boring data
indicate that the claystone portion of the Delmar Formation,
which underlies the landslide-prone hillsides along the
northern boundary, are located below approximately 310 feet in
elevation.
Santiago Peak Volcanics (JSP~ - Very dense, highly frac-
tured, irregularly weathered metavolcanic rock of the Santiago
Peak Volcanics is present in the northeastern portion of the
site along the El Fuerte Street easement.
Structure and Faulting
In general, the Tertiary age sediments in the study area
are essentially horizontally stratified or dip very slightly
to the south and west (usually less than 4 degrees).
During our site reconnaissance, no faults or indications
of faults were observed. No faults are mapped on the site.
5
C'Jdward-Clyde Consultants
Landslides
Our previous study indicated the presence of several
ancient landslides on the flanks of the canyon along the
northern property line. Subsurface exploration indicates that
these landslides are both shallow and deep-seated in nature.
No indication of landsliding was found to be present
within the subdivision boundary of the lots to be developed.
Ground Water
No ground water seeps, springs, or abnormally wet areas
were observed during our visual reconnaissance or in the test
excavations. Surface waters, from storm drains of the adja-
cent subdivision, flow intermittently in the canyon along the
El Fuerte Street easement.
DISCUSSIONS, CONCLUSIONS, AND RECOMMENDATIONS
The discussions, conclusions, and recommendations pre-
sented in this report are based on the results of our field
and laboratory studies, analyses, and professional judgment.
Potential Geologic Hazards
Faulting and Ground Breakage - Our reconnaissance, lit-
erature review, and subsurface explorations did not reveal the
presence of any faulting on the site.
The nearest known active fault along which earthquakes of
magnitude 4 or greater have occurred is in the Elsinore Fault
zone, mapped some 22 miles northeast of the site.
The closest significant faulting is the northern exten-
sion of the Rose Canyon Fault zone, which is mapped offshore
approximately 9 miles southwest of the site. No magnitude 4
or larger earthquakes have been recorded on the Rose Canyon
Fault zone.
6
.- G Project No. 51 1. { odward-Clyde Consultants
Liquefaction - The formational soils on the site are
dense to very dense, and there is no apparent permanent ground
water table within expected grading limits. In our opinion,
the formational soils do not have a potential for liquefac-
tion. The loose alluvial soils have a potential for liquefac-
tion in a saturated state. In our opinion, this potential can
be substantially reduced by over-excavation and recompaction
as recommended under "Grading. 'I
Landslides - Ancient landslides are present along the
flanks of the canyon to the north of the site. Significant
portions of these landslide masses extend onto the northern
areas of the site, but appear to remain topographically below
and removed from any proposed lot areas on the subdivision.
However, we recommend that keys made for the proposed side-
hill fill slopes be inspected by an engineering geologist from
our firm prior to placing fill in these areas to verify actual
subsurface conditions. If landslide materials are found to
extend within the areas of proposed development, it will be
necessary to remove them down to competent formational soils
prior to construction of fill slopes.
Grading plans indicate that the El Fuerte Street exten-
sion will traverse portions of the landslide masses along the
bottom of the canyon to the north of the site. Proposed
grading in this area will generally involve filling of the
canyon, which in our opinion, will tend to increase the fac-
tors of safety in the toe area of the landslide masses. No
evidence of recent slope failure were observed in the land-
slide masses.
Ground Water
We do not expect that a shallow permanent ground water
table is present within the proposed grading limits. Our
field investigation did not reveal any ground water seeps,
springs, or abnormally wet areas.
( odward-Clyde Consultants
We recommend that positive measures be taken to properly
finish grade each lot after the residential structures and
other improvements are in place, so that drainage waters from
the lots and adjacent properties are directed off the lots and
away from house foundations, floor slabs, and slopes. Even
with these provisions, experience has shown that a shallow
ground water or surface water condition can and may develop in
areas where no such water condition existed prior to site
development; this is particularly true in years of heavy rain-
fall and in residential subdivisions where a substantial
increase in surface water infiltration results from landscape
irrigation.
General Soil and Excavation Characteristics
In our opinion, the fill and natural surficial soils on
the site can be excavated with light to moderate effort with
heavy-duty grading equipment. Excavation of the Delmar Forma-
tion may require moderate to heavy ripping; excavation of
localized cemented zones in the Delmar Formation may require
heavier ripping, and may result in the generation of oversize
material.
Soils suitable for use at finish grade are present in the
Delmar Formation; however, clayey strata were present in the
recent test borings and have previously been identified in
borings. The clay portions of the formational soils are
estimated to be moderately to highly expansive and unsuitable
for use at finish grade.
The excavation of the Santiago Peak Volcanics along El
Fuerte Street between approximately Station 125 and Sta-
tion 132 will generally depend on the type of material, the
degree of weathering and decomposition, and the spacing and
orientation of the fractures. For this investigation, we have
used engineering seismograph traverses to aid in evaluating
the rippability characteristics of the hard rock.
8
- 1 , Project NO. I, d Jdward-Clyde Consultants
Excavations made in similar formational materials in
other areas of San Diego County indicate that the results of
seismic traverses can generally be correlated in relation to
rippability with a D-9 caterpillar tractor with single shank
ripper as follows:
Apparent Seismic Velocity (fps)
(4,500
4,500 to 5,500
>5,500
Estimated Rippability
Materials can generally be ripped with conventional heavy-duty equipment; how- ever, rocks exhibiting velocities as low as 4,000 fps are sometimes very hard on
blasted rock with these velocities and equipment, and some contractors have
have found it desirable to preblast prior to excavation.
Material within this range appear to be marginally rippable; the success of the excavation operation often depends on equipment performance and operator tech- nique.
Materials normally require blasting prior to excavation.
Based on the results of our seismic traverses, we inter-
pret that nonrippable conditions may be encountered along the
alignment at a vertical depth of approximately 10 feet below
existing grade. For budgeting purposes, we estimate that
approximately 4,000 cubic yards of blasting will be required.
In addition, blasting is also expected for utility trenches
along El Fuerte Street excavated to depths greater than on the
order of 5 feet into the metavolcanic material.
Throughout the alignment, local exceptions such as hard
dikes, sills, large boulders or other zones that have resisted
chemical and physical disintegration, may require blasting to
facilitate grading.
9
- , , Project No. 51( IW-UDO~
I/ { ~ odwardClyde Consultants
Slope Stability
We have performed stability analyses for the proposed
slopes using the Janbu method of analysis for deep-seated
stability. Strength parameters are based on those used for
the Carrillo Estates Unit 1 soil investigation, our work with
similar formations in nearby areas, and our professional judg-
ment. The soil parameters used are:
B C' Y
Undisturbed Materials 35 500 psf 125 pcf (Del Mar Formation)
Compacted Soil 30 450 psf 125 pcf
The results of those analyses indicate that the proposed
cut and fill slopes within the Delmar Formation have calcu-
lated factors of safety against deep-seated slope failure in
excess of 1.5 for static conditions. Stability analyses
require using parameters selected from a range of possible
values. There is a finite possibility that slopes having cal-
culated factors of safety, as indicated, could become
unstable. In our opinion, the probability of slopes becoming
unstable is low, and it is our professional judgment that the
proposed slopes can be constructed as proposed. Slope stabil-
ity calculations are attached (Appendix C).
We recommend that all slopes be properly constructed in
accordance with the project plans and specifications, and that
all slopes be drained, planted, and maintained to help control
erosion and surface sloughing.
Our experience indicates that slopes constructed at in-
clinations steeper than 2 to 1 are particularly susceptible to
10
, Project No. 51i ' W-UDO1
C~
-
,I (- jdward-Clyde Consultants
surficial sloughing in periods of rainfall, heavy irrigation,
or upslope surface runoff. Periodic slope maintenance, in-
cluding rebuilding the outer 18 to 36 inches, may be required.
Sloughing of fill slopes can be reduced by overbuilding the
slopes by at least 3 feet and cutting back to the desired
slope.
We recommend that the proposed fill slopes be backrolled
at maximum &foot fill height intervals: 1-1/2 to 1 fill
slopes should be overbuilt 3 feet and cut back to desired
slope; 2 to 1 fill slopes should be trackwalked upon
completion.
No specific analyses of cut slopes in the metavolcanic
rock was done. It has been our experience that cut slopes in
such materials typically have low probabilities of deep-seated
failure, and the stability of such slopes is dependent upon
the orientation and spacing of fractures.
We recommend that an engineering geologist from our firm
inspect all cut slopes during grading to verify actual geo-
logic conditions and to provide design modifications, if
needed. If adverse conditions, such as clay seams or ground
water seepage, are encountered during inspection, slope but-
tressing may be required. Buttress recommendations will be
given during grading, if necessary.
Grading
We recommend that all earthwork be done in accordance
what the attached Specifications for Controlled Fill (Appen-
dix D). Woodward-Clyde Consultants should observe the grading
and test compacted fills.
We recommend that a pre-construction conference be held
at the site with the developer, civil engineer, contractor,
and geotechnical engineer in attendance. Special soil
handling and the grading plans can be discussed at that time.
11
Project No. 51( .W-UDO1 - I/ .. ( Jdward-Clyde Consultants
We recommend that the undocumented fill soils on the site
be excavated and have any oversize and deleterious materials
extracted prior to their use as recompacted fill. We recom-
mend that all trash, construction debris, and waste materials
be removed from the site before grading. We recommend that
oversize materials (between 2 and 4 feet) be placed in accor-
dance with the attached Oversize Rock Placement Areas (Appen-
dix E). We recommend that no rock fragments larger than
4 feet in size be used in fills.
We recommend that all porous topsoils, alluvium, and
other loose soils not removed by planned grading be excavated
or scarified as required, watered, and then recompacted prior
to placing any additional fill. We recommend that the soil
engineer evaluate the actual depth and extent of excavation in
the field at the time of grading.
Highly expansive clayey soils could be encountered at
grade in areas of shallow cuts and fills (daylight areas), or
in deeper cuts. We recommend that these clayey soils be exca-
vated, where encountered, over the entire level lot area to a
minimum of 2 feet below finish grade, and then be replaced
with properly compacted, nonexpansive soils or slightly expan-
sive soils available on the site. The more clayey soils can
be placed and properly compacted in the deeper fill areas.
We recommend that the upper 2 feet of materials in the
fill areas be composed of finish grade, granular soils.
Finish grade soils are defined as granular soils that have a
potential swell of less than 6 percent when recompacted to
90 percent of maximum laboratory density at optimum moisture
content, placed under an axial load of 160 psf, and soaked in
water.
We recommend slightly to moderately expansive soils, that
is, soils swelling between 3 and 6 percent, be compacted at
12
< Jdward-Clyde Consultants
moisture contents of 3 to 5 percent over optimum water content
when they are used within 2 feet of finish grade.
Foundations
We recommend that foundations for structures founded in
natural or properly compacted, finish grade soils be designed
for an allowable soil bearing pressure of 2,000 psf (dead plus
live load). In our opinion, this bearing pressure can be
increased by up to one-third for transient loads caused by
wind or seismic forces. For these bearing pressures, we rec-
ommend that all footings be founded a minimum of 12 inches
below compacted fill or undisturbed cut lot grade, be a mini-
mum of 12 inches wide, and be founded a minimum horizontal
distance of 8 feet from slope faces.
We recommend that foundations founded in slightly expan-
sive material (3 to 6 percent swell) be reinforced top and
bottom with at least one No. 4 steel bar, and that the con-
crete slabs-on-grade be a minimum 4 inches thick and be under-
lain by 4 inches of coarse, clean sand and reinforced hy
6 x 6, 10/10 welded wire mesh. A plastic membrane should also
be provided under slabs.
RISK AND OTHER CONSIDERATIONS
We have observed only a small portion of the pertinent
soil and ground water conditions. The recommendations made
herein are based on the asssumption that rock and soil condi-
tions do not deviate appreciably from those found during our
field investigation. If the plans for site development are
changed, or if variations or undesirable geotechnical condi-
tions are encountered during construction, the geotechnical
consultant should be consulted for further recommendations.
We recommend that the geotechnical consultant review the
foundation and grading plans to verify that the intent of the
13
Project No. 511 .W-UDOl - ,I ', ( Jdward-Clyde Consultants
recommendations presented herein has been properly interpreted
and incorporated into the contract documents. We further rec-
ommend that the geotechnical consultant observe the site
grading, subgrade preparation under concrete slabs and paved
areas, and foundation excavations.
It should also be understood that California, including
San Diego, is an area of high seismic risk. It is generally
considered economically unfeasible to build totally
earthquake-resistant structures; therefore, it is possible
that a large or nearby earthquake could cause damage at the
site.
Professional judgments presented herein are based partly
on our evaluations of the technical information gathered,
partly on our understanding of the proposed construction, and
partly on our general experience in the geotechnical field.
Our engineering work and judgments rendered meet current pro-
fessional standards. We do not guarantee the performance of
the project in any respect.
This firm does not practice or consult in the field of
safety engineering. We do not direct the contractor's opera-
tions, and we cannot be responsible for the safety of other
than our own personnel on the site; therefore, the safety of
others is the responsibility of the contractor. The contrac-
tor should notify the owner if he considers any of the recom-
mended actions presented herein to be unsafe.
14
Subdivision
LEGEND:
Unicornio Street + Indicates approximate location of Test Eoring.
Indicates approxinate location of Seismic Traverse.
Indicates approximate location of existing ground surface contour.
ltidicates approximate limits of existing Carrillo Estates Unit 1.
Indicates approximate limits of existing landslide.
Indicates approximate limits of existing fill slope.
Indicates approximate limits of compacted fill.
Indicates approximate limits of Alluvium.
Indicates approxinate limits of Delmar Formation.
Indicates approximate limits of Santiago Peak Volcanics.
SITE PLAN AND GEOLOGIC MAP
CARRILLO ESTATES UNIT 2
Dn*)*NnV: mrk I CHLCKEDBY:$& 1 PRWECTNO 51142\f/-UD01 1 DATE: 4-24-81 FIGURE m): 1 " WOOOWARO-CLYOE CONSULTANTS
d,dward.Clyde Consultants
APPENDIX A
FIELD INVESTIGATION
For our current investigation, two exploratory borings
were drilled at the approximate locations shown on Fig. 1.
The test excavations were made with a truck-mounted, 30-inch
diameter bucket auger, and down-hole logged by an engineering
geologist from our firm. Representative samples of the sub-
surface materials were obtained from the test explorations.
The seismic traverses were performed with a Nimbus ES-125 Sig-
nal Enhancement Seismograph.
The locations of the test borings and seismic traverses
were estimated from aforementioned grading plans prepared by
Rick Engineering Company.
A- 1
- I , Project No. 51
3, d ddward-Clyde Consultants
TABLE A-1
SUMMARY OF ENGINEERING SEISMOGRAPH TRAVERSES
Traverse
Number Velocity Depth Interpretation (ft/sec) (feet) of Rippability
s-1
s-2
1,290 0 - 12
5,100 Rippable
1,200
6,000
12+ Marginally rippable
0- 9 Rippable
9+ Nonrippable
c
1 1 12 110
Location
DEPTH TEST OA
Boring Number Elevation
ITHER SAMPLE Em NUMBER SOIL DESCRIPTION
21 i L WATER LEVEL A
SOIL CLASSIFICATION
At time of drilling or as indicated.
Soil Classifications are baed on the Unified Sail Clauiliation System
and induds mlor. mowwe and EomistenLy. Field deVriPtlonr have
kn modified to reflect results of laboratw analyscs where
wproprste.
2
DISTURBED SAMPLE LOCATION Obtamed by collecting the auger cuttings in a plastic or do* bag.
DRIVE SAMPLE LOCATION MODIFIED CALIFORNIA SAMPLER
Sample With recorded blows per foot was obtained with a Modified
California drive ramnlar 12” inside diamter. 2.5 outside diamterl
INDICATESSAMPLE TESTED FOR OTHER PROPERTIES GS- Gram Size Dirtr~but!on CT - Conrol~datton T-1
LC - Laboratory Compaction UCS - Unconfined Compression Test
ST - Loaded Swell Test
PI - Atletberg Lmitr Test DS - Direct Shear Test
CC-Confmed Compression ‘R’- value
TX- Trmr~al Compression Tell
NOTE: In thll column the re~lts of rhea test1 may bs recorded
Test SDS - Slaw Direct Shear Test
TBII
where appltcabh.
BLOW COUNT
DRY DENSITY
MOISTURE CONTENT
Pounds per Cub$= Foot
Number of blows needed 10 advance sampler one foot or as mdlcated.
Percent 01 Dry Weqht
KEY TO LOGS
CARRILM ESTATES UNIT 2
DRAWN BY: mrk 1 MECKED BY:$^ 1 PROJECT No: 51142W-UDO1 1 DATE: 4-24-81 I FIGURE NO: A-1
WOODWARD-CLYDE CONSULTANTS
7;
'For descriptmn of symbols. see Figure A-1 I MG OF TEST BORING 1
CARRILLO ESTATES UNIT 2
WOODWARD-CLYDE CONSULTANTS
ji+ DEPTH
, 50 45r
65
70
75 3
c'
Boring 1 (Continued)
SOIL DESCRIPTION I Dense to very dense, damp, light yellow
brown silty fine sand (SM)
DELMAR FORMATION
Hard, damp, light gray silty claystone (cL)
DELMAR FORMATION
Dense, damp, red brown silty sand (SM)
DELMAR FORMATION
\ Hard, damp, gray silty claystone (CL)
DELMAR FORMATION L" - gradational contact - - - -
Hard, damp, gray, very fine clayey to sandy
siltstone (MI,) DELMAR FORMATION
Cemented zone
Hard, damp, gray silty to sandy clay (CL)
DELMAR FORMATION
Very dense, damp, light gray silty fine
sand (SM) DELMAR FORMATION
Near horizontal bedding at 58'
\ Dense. moist, red to yellow, silty sand
(SM) DELMAR FORMATION
Dense, damp, light gray silty fine sand
(SM) DELMAR FORMATION
Bottolr of Hole
'For description of symbolr. SI). Figrre A-1
LOG OF TEST BORING 1 (Cont'd)
CARRILLO ESTATES UNIT 2
DRAWNEV mrk I CHECKEDEY:@ I PRWECTNO: 511421.1-UW1 I DATE 4-24-81 I flGURENO:A-3
WOODWARD-CLYD€ CONSULTANTS
Boring 2
DELMAR FORMATION
Cemented concretion
Cemented concretion
Near horizontal bedding
'For darCriDtian of symbols. see Figure A-1 I LOG OF TEST BORING 2 1 I CARRILM ESTATES UNIT 2 I
DRAWNEV mrk 1 CHECKEDBV#(j I PROJECTNO:51142W-UDOl I DATE: 4-24-81 I FIGURE NO:A-4
WOODWARO-CLYDE CONSULTANTS
3. 1, Project No. .'
/
Us, Jward-Clyde Consultants
APPENDIX B
SOIL INVESTIGATION FOR THE PROPOSED
CARILLO ESTATES
CARLSBAD. CALIFORNIA
September 6, 1973
Project No. 73-203
7.'
~ 8, b . . Project NO. 51 I 42W-LID01 <'
. SOIL INVESTIGATLON FOR THE PROPOSED ..
CAR'ILLO' ESTATES .. ..
CAKLSBAD, CALIFORXl'A
PONDEROSA HONES 2082 Business Center Drive
Irvine, California 92664 .Suite 100
WOOO!lARD-GIZIENSKI & ASSOCIATES Consulting Soil and Foundation Engineers and Geologists
(An Affiliate of Woodward-Clyde Consultants)
.*I I' L
: . Project No.
TABLE OF CONTENTS
LElTER OF TRANSMITTAL
SCOPE
FIELD INVESTIGATION
LABOPATDRY TESTS
SITE, GEOLOGIC AND SOIL CONDITIONS
CONCLUSIONS AND RECON4ENDATIONS
LIMITATIONS
TABLE I .- SUMMARY OF SEISMIC TRAVERSES
FIGURE 1 - SITE PLAN
FIGURES 2 THROUGH 12 - LOGS OF TEST BORINGS
Page
1
2
3
3
5
10
FIGURES 13 THROUGH 15 - LOGS OF TEST TRENCHES
.F.IGURES 1.6 .AND 17 - FILL SUITABILITY TESTS
FIGURES 18 THROUGH 21 - DIRECT SHEAR TESTS
B-2 WOODWARD - CIZIENSKI & ASSOCIATES
C0"I"L.I". *a. ."0 .OUO.IoI <.C(",I.* ..DC,OIOS,,.,
a, .. , Project No. ,
September 6, 1973' Project No. 73-203
.+
Ponderosa Homes ' 2032 Business Center Drive Suite 100 Irvine, California" 92664
Attention: Mr. Donald W. Gales
c
In accordance with our asreements dated June 8, 1
..
.... .. ..
973 and Jul~ . 1973, we have made an investigation of the underlying soil conditions at the
California. site of the proposed subdivision to be known as Carillo Estates in Carlsbad,
The results of our studies indicate that the ,site is generally suitable. for the proposed development; however, there is some hard rock that may require blasting and existing "old" landslides in the northeastern canyon may require special treatment or real'ignment of the proposed el Fuerte Street. The extent of the existing landslides are not anticipated to be within the proposed lot areas and are not expected to pose construction
expansive and it appears that selective grading will be necessary to problems in these areas. Much of the on site material is potentially
provide nonexpansive soils in the upper portions of level lot pads.
The accompanying report presents our conclusions and recommendations, as well as the results of the subsurface exploration and laboratory tests upon which these recommendations are based.
The engineer assigned to this project was Joseph G. Kocherhans. If you . have any questions, please call at your convenience.
WOODI~lkRD-GIZIE[.ISY,I & ASSOC!ATES
L'dwis J. Lee ' R.E. 14129
LJL/JGK/mf
Attachments
(2) Ponderosa Homes (4) Rick Engineering Company
fl
B-3
-. (- -.i
I. . Project NO. 5 .-;2N-UDOl c
w v
SCOPE
This report describes an investigation of the underlying soil ..
and geologic conditions at the site of the proposed subdivision to be
known as Carillo Estates. The site is located approximately 1 mile
east of El Camino Real and 1 mile south of'Palomar Airport Road in Carlsbad,
California. The purpose of the investigation is to make a geological
and soil investigation of the,site that will provide a basis for conclusions
and recommendations regarding the stability of the proposed cut and
fill slopes; any required fill foundation treatments and special provisions
that are necessary in the earthwork specifications; the most suitable
type and depth of foundation and allowable soil bearing pressures for
foundations on compacted fill or natural ground; and provide conclusions
I. \
-
and recommendations regarding the relative stability and the necessary
measures to improve the stability of exi.sting "old" landslides. The
results of our engineering geological reconnaissance have been presented
in our letter dated June 4, 1973. Preliminary results of our investigation
have been presented to the subdivision engineer, Rick Engineering Company,
to assist them in developing plans for the subdivision.
It is our understanding that the proposed area is to be developed
. into lots for single family housing which will consist of one and two-story
structures, of wood frame construction. It is anticipated that the
residential structures will be supported on continuous footings or on
a pier and grade beam foundation and that house floors will either be
raised wooden floors or concrete slabs-on-grade.
The specific plan and tentative map of Carillo Estates. prepared
Project No. 51 IZW-UDO1 -
I. .. . t
i s by Rick Engiwiing Company and dated May 7, 1973, indicates that maximum
cut slope heights of approximatly 40 feet at maximum slope inclinations
of 1-1/2 to 1 and maximum fill slope heights of 110 feet at an inclination
of 2 to 1 and less than 30 fe'et at inclinations of 1-1/2 to 1 are proposed.
FIELD INVESTIGATION
Ten test borings were made with a 6-in. diameter truck-mounted
power auger, four test borings were made with a 30-in. diameter bucket
rig and seven test trenches were excavated with a caterpillar D-8 dozer.
The approximate locations of the test borings and test trenches are
shown on the Site Plan, Fig. 1. The drilling of borings and trench
excavations were done between June 5 and June 11, 1973 under the supervision
of a project engineering geologist. Field logs were prepared by the
geologist on the basis of an inspection of the samples secured and of
the excavated material. The Logs of Test Boring and Test Trenches,
shown on Figs. 2 through 15 are based on an inspection of the samples,
the laboratory test results, and on the field logs. The vertical position
of each sample is shown on the Logs of Test Borings and Test Trenches.
..
In addition to the test borings and excavations, three engineering
seismograph traverses were made on June 11, 1973 at the approximate
locations shown on Fig. 1. Our interpretation of the results of the
traverses is presented on Table 1.. . '
The test excavations and seismograph traverses were located
in the field with the aid of.an undated, untitled 1"=100' scale topographic
map submitted to us by Rick Engineering Company.
a-5 WOODWARD - GlZlENSKl 6 ASSOCIATES
"",I," sal, ..e .(11"0.1,01 .W*,.ma UD "-.I.
Project No.
' LAGORATORY TESTS
The soils encountered were visually classified and evaluated
with respect to strength, swelling and compressibility characteristics,
dry density and moisture content. The classification was substantiated
by grain size analyses and determination of plasticity characteristics I
'of representative samples .of the soils. Fill suitability tests, including
laboratory compaction tests, direct shear tests, loaded swell tests, plasticity
characteristics and grain size^ analyses, were performed on samples of
the basic materials. encountered and expected to be used as fill. The
-
strength of soils was evaluated by consideration of the density and mositure
content of the samples and the penetration resistance of the sampler,.
The results of tests on relatively undisturbed drive samples
are shown with the penetration- resistance of the sampler at the corresponding
sample locations on the Logs of Test Borings. The fill suitability test
results, except direct shear tests on compacted samples, are reported
on Figs. 16 and 17. The resu'lts of the direct shear tests are reported
on Figs. 18 through 21. ,,.
SITE, GEOLOGIC AND SOIL CONDITIONS
The site is located on a northwesterly trending ridge with a
high elevation of this ridge, at the southeastern corner of the property,
of approximately 480 ft. The upper portion of the ridge extends downward
to the northwest to an elevation of approximately 325 ft near the northwestern
corner of the property. A canyon exists on the northern and eastern side
of the site that extends down to elevation of approximately 150 ft. The
side slopes of this canyon are relatively steep ranging between approximately
1.3 to 1 (horizontal to vertical) to approximately 4 to 1. The side slopes
B-6 WOODWARD - GlZlENSKl b ASSOCIATES
C"II"0 l0.L mco IOU.0A.L I".".. YO UODCI.,.
Project No. 5 142W-UD01 4- rage 4
- t. ..
*a '' on the western side of the ridge are at an inclination of generally'about "
6 to 1. At the present time the site is covered with mall weeds and has
sparse coverages of small brush with locally dense growth. A- small fill
that appears to be uncompacted exists near the end of Flamingo Street.
Our investigation reveals that there are four distinct geologic
units present on the property. These. units are from youngest to oldest:
Alluvium, a late Pleistocene Terrace deposit, Tertiary sediments, and
Santiago Peak volcanics. A general description of each of these units
is given below:
natural drainage channels on the site. The alluvial materials consist, for the most part, of silty and clayey sands with minor amounts of scattered'gravels in thicknesses up to approximately 6 ft, as exposed in the test trenches.
Alluvium - The alluvium deposits are mainly confined to the
Terrace Deposits - These deposits exist in a limited amount on the surface of the northernmost portion of the main ridge traversing the site. These deposits generally consist of silty clay materials
and were obserGed to be less than 2 ft in thickness.
Tertiary Marine Sediments - Materials.of this fortnation make
grading. The soils within this unit consist of interbedded friable up the bulk of the material requiring excavation for the proposed
sandstones and poorly indurated claystones. The majority of materials above an approximate elevation of 403 ft are generally interbedded sandy clays and silty clays.
Jurastic Santiaro Peak Volcanics - These metavolcanic rocks occur at the surface within 2 areas on the property, at the approximate locations indicated on the Site Plan. These rocks typically have large variations in decomposition and fracturing in short surface distances; that is, some areas are expected to be excavated fairly easily, whereas an area just a few feet away may require blasting for economical removal of the materials.
The near surface soils. as encountered in the test borings,
generally consist of 1 to 2 ft of silty sand that is porous. This topsoil
is generally underlain by a layer of residual silty and sandy clay ranging
in thickness from absent to 3 ft. ..
B-7
Page 5
n Test Borings 4 and 5 were dug in an area of existing landslides.
A slide plane was encountered at a depth of approximately 6-1/2 ft in
Boring 4, but none was encountered in Boring 5. The materials observed in
Boring 5 appeared to be slide debris for the entire depth of the boring.
It was also noted that the bedding of the material at depths of 24 ft
and 30 ft was approximately 30 degrees out of the slope. Refusal was
encountered on very hard cemented sand in Boring 5 at a depth of 34 ft.
No g?oundxater was encountered in the test borings at the time
of our investigation.
' 'CONCLUSIONS AND RECOM!~lENDATIONS
(1) The results of our investigation indicate that there are
several "old" landslides on the property, that much of the soil within the
anticipated depths of grading is potentially expansive and that there is
some "hard" rock within proposed cut areas. It is our opinion that select
grading and special inspection will be required in order to provide the
most suitable end product. It should be anticipated that special foundation
designs may be required for structures on potentially expansive soils.
(2) The ground which will receive fill and/or residential structures
will, in our opinion, have an adequate bearing value to safely support
the proposed loads when treated as described in the following paragraphs
and in the attached "Specifications for Controlled Fill". Footings for
residential structures placed on nonexpansive undisturbed soils or properly
compacted nonexpansive soil may be designed for a soil bearing pressure
of 2000 psf at a depth of 12 in. below rough lot grade. Footings should
have a minimum width of 12 in.
Project No. 51 42W-UD01
<',.
(,- \
Page 6
(3) The upper zones of th? Santiago Peak Volcanics, the residual
clay below the topsoils, the terrace clays and the sandy and si1 ty clay
strata in the Del Mar Formation, have been classed by laboratory tests
as being potentially expansive to varying degrees. Our studies indicate
that the bulk of the material excavated from above the approximate elevation
of 400 ft will be of the potentially expansive nature. Where these soils
are used within 2 ft of finish grade in either cut or fill pads, special
foundation treatment will be necessary. For your convenience and consideration,
the following two preliminary foundation designs are presented for soils
having 3 to.6 percent swell potential and for soils having 6 to 9 percent
swell potential :
B-9 WOODWARD - CIZIENSKI & ASSOCIATES
CO..lnI6.. so$, .lo fMD1IIDI .".."*'". ..O U",.
Project No. 5 - L
‘i The above footings may be designed for a soil bearing pressure of 2000
psf. Soils having a potential swell in excess of approximately 9 percent
should not be used within the upper 2 ft of rough lot grade. Potentially
expansive soils encountered may be spread and compacted throughout the
lower portions of fills, but should not be used in the outer zones of
fill slope faces, as will be discussed in the paragraph under slope stability
-
-
bel ow.
(4) The results of our investigation indicate that the bulk
of the select materials not requiring special foundations will generally
be encountered below the approximate elevation 400 ft. Because of this, ,
it may be desirable for this office to review the proposed grading plan
when completed and possibly make additional studies in order to evaluate
the availability of select material for capping the upper 2 ft of all
lots founded in potentially expansive-materials. The final result of
this may enable us to delinate areas and volumes where the select materials
are available and estimate where the potentially expansive soils will
require undercutting and thereby provide a basis for selective gradi.ng.
(5) Kesults of our geological reconnaissance, the test borings
and test excavations, and the engineering seismograph traverses indicate
that the materials on the site can generally be excavated by normal heavy
grading equipment, except in the Santiago Peak formation. Within this
formation, it is anticipated that blasting will generally be required to
achieve final grades in areas where cuts are in excess of approximately
5 to 15 ft. In those areas where outcrops exist, blasting will be required
at the surface. It is recommended that areas requiring blasting be overexcavated
to a minimum depth of 2 ft below the proposed rough grade and that the
-
B-10
Project No.
(. *
Page a
excavation be backfilled with the more select materials available on the
site. I.le have discussed the general anticipated areas of blasting with Rick
Engineering Company and suggested that raising grades in certain areas may
be helpful to minimize the amount of blasting required.
It should be anticipated that some oversized rock will be generated
in areas that are blasted. .Material in excess of 2 ft in least dimension
will require special handling to place and use in the deeper portions
of fill; that is, when larger rock fragments are used in fills they should.
be completely isolated, such that there is at least the width of the compaction
equipment between rocks in order to allow for adequate compaction of the
soils around the rock.
- (6) It is recommended that loose and/or porous surface soils
which are not removed by the grading operations be excavated or scarified
as required, replaced and compacted before fill, footings or slabs are
constructed. These materials range in depth from approximately l-l/Z
to about 3 ft on the ridge and side slopes up to approximately 6 ft in
the bottoms of the natural drainage channels. Because of the variations
in thickness of the loose and/or porous surface soils, their excavation
and compaction should be controlled in the field by Woodward-Gizienski &
Associates upon visual examination of the exposed soils.
(7) The proposed cut and fill slopes having inclinations of
1-1/2 to 1 (l-l/Z horizontal to 1 vertical) and maximum unsupported heights
of less than 50 ft will, in our opinion, have an adequate safety factor
against slope failure if constructed in accordance with the plans and
specifications. Fill slopes in excess of 50 ft in height.but.less than
115 ft in height.may be constructed at overall slope ratios of 2 to 1.
.. Page 9 Project No. 51142W-UD01
It is recommended that the lower portions of the fill in those areas where
the slope exceeds 50 ft in height be constructed of materials similar
to samples 3-3 and 14-1 in the outer 60 ft of slope face. As grading
progresses, strength tests on newly exposed soils combined with other
slope stability analyses may show that these newly exposed soils may also
be used within this zone. . .
(8) As previously noted there are existing old landslides along
the northern side slopes of the major ridge of the site. Although these
slides appear to be below'the toes of proposed fills, it is recommended
that the keys made for these proposed fills be inspected by a geologist
from our firm prior to placing fill in these areas in order to verify-actual
.' subsurface conditions. This recommendation is made for the purpose of
inspecting the area for possible slide debris that could not be delineated
from the field reconnaissance. Should such materials be encountered,
it will be necessary to remove them down to competent formational materials
prior to construction of fill slopes.
(9) As presently proposed on the tentative map, by Rick Engineering
Company, el Fuerte Drive is planned such that' relatively high cuts would
be made on the western side of the proposed alignment. , Results of our
studies indicate that landslide masses exist in this area and that extensive
buttresses would be required to stabilize these cuts. We have therefore
recommended to Rick Engineering Company that the proposed alignment of
el Fuerte Drive be moved farther to the east in order to fill the canyon
bottom and make no cuts on the side slopes on the west side of the proposed
street. They have indicated that this alignment change is possible.
It is recommended that final plans in this regard be reviewed by this office
B-12 WOODWARD - ClZlENSKl b ASSOCIATES
LO..YLII.s .p, 110 m""D..W. '.C,.,l.. 1.D 'IOIOC.',.
Project No. 5 "425J-UD0l I. c Page 10
in order to determine the relative stability of this area and provide any
additional recommendations that may be required.
(10) A set of 'Specifications for Controlled Fil1"'is attached.
Recommendations made as a part of this report shall become a part of these
specifications. It is recommended that all .grading operations be observed
and compacted fi1,ls be tested by Woodward-Gizienski & Associates.
LIMIATIONS
The conclusions and recommendations made in this report are
based on the assumption that the soil conditions do not deviate appreciably
from those disclosed by the test borings. If variations are encountered
during constuction, we should be notified so that we may make supplemental
reccmmendations, if this should be required.
..
Evaluation and utilization of soil materials for support of
structures.includes investigation of the subsurface conditions, analysis,
formulation of recommendations, and inspection during grading. The soil
investigation is not completed until the soil engineer has been able to
examine the soil in excavations or cut slopes so that'he can make the
necessary modifications, if needed. We emphasize the importance of the ' .
soil engineer continuing his services through the inspection of grading,
including construction of fills, and foundation excavations.
B-13 WOODWARD. GIZIENSKI & ASSOCIATES
co...u.mo .oI 1.0 .OY.PIIO. '"L'.,I., .I. UOLOU.,.
. Project No. 5(' 42W-UDOl
i
i \
SUMI4ARY OF SEISMIC TRAVERSES
Traverse Velocity (ft/sec) Depth' (ft)
TR-1 2750 0-2
3900 2 - 14
13000 . 14 - 31
20000 31+
' TR-1R -
.TR-2
TR-2R
TR-3
TR-3R
20cc
10000
2200
6500
20000
2400
7200
12000
0 - 50
55+
0-7
7 - 40
40+
0-7
7 - 31
31 +
2250 0-5
4300 5+
1600
2600
0-4
4 - 17
7000 17+
..
a-14 lVOODYlARD - ClZlENSKl & ASSOCIATES
CO.(.YLI,.. 9o.L YO ,OU.D..*l I".. ..* U"""
Project No.
3
150
..
4 Indicates approximate location .
of test boring-(30" bucket).
Indicates approximate I imi ts of ' of test trench.
Indicates approximate location
,." Indicates approximate existing
,' ;!/*' v ground surface contour.
Indicates approximate limits
exposed at ground surface.
Indicates approximate
f location of seismic traverse.
SI TE PLAN @ of Santiago Peak Volcanics CARRILLO ESTATES
LKKICdARD - GIZIENSKI 6 ASSGCIATES
COWSULTIYG SOIL UD FOUNOATIOY EXGIWEECS AND GEOLOCISTS
S~Y nIm. cLLlfo;irlA
02. BY:' LIS zpwnt. SC~~E: I* = COV~ m.1, m: 71.7~
Ry:CJ'r-zl OITF: E-15-73 LFJQI;.E.&A """-
n 7r
Project No. 5I$42:+UDOl
0-
5-
IO -
I5 -
20 -
30
33
BC = 20
Bc= 27
WC = 16
BC = 92 DD = 110
c
bring I
Y
For Legmd, see Figure 4.
LOG OF TEST BORING I
CARR I LLO ESTATES
bring 2
0- Loose, dry, tan si 1 ty sand [SI) .
Hard, damp, brown sandy clay (U) BC = 18 Porous
5- Hard, mist, gray to yellowbrown clayey si 1 t to fine sandy clay (ML-
wc = -16 DO 107 BC = 65 ,
Hard, moist, interbcdded gray-bmm sandy clay and olive silty clay (U-
WC = 22 OD = 102 BC = 63 15 -
20 -
Very dense, damp, gray-brown clayey
szid (3.4-SC) with shells
cmen ted BC = 84 ,. .
25 - .,
For Legend, see FigJre k
LOG OF TEST BORING 2
CARR I LLO ESTATSS
1- (OYSULTIqG SOIL LUD FOUYDATIC!I ENCIYEERS AND GEOLOGISTS LfXXLiRD - GIZIENSKI 6 ASSOCIATES
Project NO. (:
bring 3
Stiff, mist, red-brown sandy clay
Hard, mist,. brown sandy clay (a)
knse to very dense, mist, gray-
clayey sand (SC) . '
EC = 72
<... .. ..,.
,<. ,., ,.::.,. ,9 . ,., . ... ,:
.j'. :i:
:. .: .. ..
.. , ., .. ...,~
.,...._,
.$_I. .. . , ... .. ..... ..., :.. I
I . 2. , ..
Refusal
LEGEHD
WC = Water Content in percent of dry weight.
DD = Dry Density in pcf.
8C = Number of blows by I40 ound hammer falling
Sampler Data: ID = 2.0". OD 3 2.5": 35 inches to drive sampyer 12 inches
(SH) = Grou classification symbol in accordance with the [nified Soil Classification System. 4 = Sample Number.
Refusal = Unable to extend excavation, practically, with equipment being used in the exploration.
r
LOG OF TEST BORING 3
CARgILLO ESTATES
i
Project No. 51142IV-UDO1
{~
0
5
IO
15
20
25
33
'. * ..
. :
Y
ar
For Legend, see Figure 4.
I LOG OF TEST GORING 4
CARklLLO ESTATES
Project NO. 5c'2W-UD01
For Lcgcnd, see Figure 4. LOG OF TEST BORING 5
CARR I LLO ESTATES
Project No. (
0
5
m 8
't a 15
"0 c z W
33
35
40
bring 6
- I-ledium dense, dry, brow si Ity sand \ Irn) Porous
.. kse to very dense, damp, light
.. .'.; brown silty fine sand (s)
.. ..
j *
,: . .. .. .
. .., .. .,
: , ....
1, : :;i
. .. .
,<."
. ...
: (a) with cemented layers and fossils .. .
Very dense, damp, brcwn si Ity sand
..
3 ':. 1 .1 ~ . ,... .. . ,.. ,.: .L ..I .. .,
..
Refusal
bring 6
- I-ledium dense, dry, brow si Ity sand \ Irn) Porous
.. kse to very dense, damp, light
.. .'.; brown silty fine sand (s)
.. ..
j *
,: . .. .. .
. .., .. ., , .... : . .. .
1, : :;i
,<."
. ...
(a) with cemented layers and fossils : Very dense, damp, brcwn si Ity sand
.. .
..
3 ':. 1 .1 ~ . ,... .. . ,.. ,.: .L ..I .. .,
..
Refusal
For Legend, stx Figure 4.
.-
Project No.
0
5
IO
15
.x)
25
30'
35 '
40-
43-
bring 7
t
Porws
(CH) with thin interbeds of clayey
silt (M)
dmp, gray-brow clayey
Very dense, danp, light gray silty
fine sand (34)
br Legend, see Fi gure 4.
LOG OF TEST BORING 7
CARR I LLO ESTATES
Project-No. S~"2W-UDOl
5
9 I
0
5
IO
OI 9 5
(.. ' ,
bring 8
BC =
BC =
BC =
21
95
59
Loose, dry, br0v.n silty sand (34)
Dense, danp, gray-bran clayey sand
Porous
(SC) SI ightly Porous
Dense to very dense, mist, yellow-
" brow silty fine sand (%)
bring 9
BC= 13 ..! Medium dense? dry to dmp, brm
silty sand (34) powus
BC = 18 Hard, moist, bmhn sandy clay (CL)
b\\\l
silty fine sand (N)
Very dense, mist., yellow-brohn
ec= 56 ..
bring IO
Ckdium dense, dry, brown silty sand
Porous
mist, brwn sandy clay (CL) Wc = 13 OD = ICa BC = 33
Very. dense, mist, yello-w-bmwn
8C -- :I clayey sand (SC)
i -I
I
" """"_
cuntinued on next page
For Legend, see Figure 4.
LOG OF TEST 60RIHG II
CARR I LLO ESTATES
MXWARD -GIZI€NSKI & ASSCIATES COW9JLTIHt SOIL MD FWWDiTlC4 EXCIMEEES AllD CECLOGISTS
-
*
C~J. w: 727n1
nrii: 8-1b73 FIr'?!iw. Io CY'D _."" EY: ,!+&I d""- ... .: - .. -..
i
Project No.
30
35
40
44
0
5
IO
13
"(' 2'rJ-UDo1
ec =
6C =
- 2
bring II continued
l-"""""" ard, mist, gray silty clay (CL)
Very dense, mist, yellow-brcm clayey sand (SC)
with fossi Is
Very dense, mist, olive clayey
silt (hL)
Very dense, moist, gray-brown clayey
bring 12
Hard, dry, bladc sandy cky (Ci)
knse to very dense, mist, yellow-
brown silty fine sand (%)
:..I ..
..
For Legend, see Figure I).
Project No. 5p42W-UDOl /,
n, bring 13 H,. I sand ($!.f)
Mi urn dense, dry, grapbrom si 1 ty
Porous
Hard, mist, red-brown sandy clay
Hard, mist, gray-brow sandy clay
(U-W
( cL-ai )
Hard, mist to Mt, dive silty clay
Bc= 53
15 dense, mist,' grzy-brom silty
,: j :, to clayey sand (X-SC) I 6C = 4516"
For Legend, see Figure 4.
LOG OF TEST BORING 13
CARRILLO ESTATES
CCU%JLTIYG SOIL US FOUYOATICX f.NGII(EERS AND GEOLOGISTS LCSWGRD - GIZIENSKI 6 ASSCIATES
SAM DIEU. ChLliO3lA
Project No. 5 22iJ-UDO1 t ('
0
5
13
15
20
5
9 I
bring I4
Losse, dry, brown silty sand (a)
Dmse, dmp, gray-brow si 1 ty fine
Porous
i '. ,{ ! :' .::,
,! '. . .
1 .: ;, ..,
!.
wc = IO OD = 100 . . ... BC = 2316'
.:.:
wc = II DD = 105 BC = 44
Trench 15
Lcoso, dry, dark brw clayey fine
sand [SC) Porous
V'di urn dense, dmp, brown si 1 ty to
clayey sand (SMC) with fossi 1 s
Hari, mist, gray-brohn silty clay (a)
V'di urn dense, dmp, brown si 1 ty to
clayey sand (SMC) with fossi 1 s
(IxH)
Hari, mist, gray-brohn silty clay
For Legend, see Figure 4.
LOGS OF TEST BORING 14 AND TEST TRENCH 15
CARRILLO ESTATES
Project No. 5 42X-UD01 r
5
7 O1
0
5
IO I
5
6
Trench I6
Hard, moist, brow sandy clay (Cl)
Dense to very dense, danp, gray-
brown silty fine sand (Sf)
.'. <'?.. i
'.
.. .
.,
.. . .. .. . .. : ...
..
,, .;i.
Trench 17
e, dry, light brown silty
, dark brown si 1 ty sand
Porous --:::'::. Medium dense, damp, brown clayey
-\ sand (SC) Porous
'...!... Dxtse to very dense, danp, 1 ignt
': gray-brown si1 ty sand (SA) .
,.
.. .,
". . .: i:i
,, .~.. '.... c
~. .
...
.',: >> '1
Trench 18 4 Lase, dry, dsrk brown silty smd
f2.1) Porous'
Hard, damp, dark brow sandy clay
Dense to very dense, danp, gray-
brm si 1 ty sand (2.1)
.For Legend, see Figure 4.
LOGS OF TEST TRENCHES '16, 17 AND 18
CARRI LLO ESTATES
J
Project No.
6
a
5
7 OI
(c
I
Trench 19
Loose, dry, dark brown clayey sand
2 (XSSC)
: Dense to very dense, damp, gray-
:. brorn clayey sand {SC)
Very dmse, danp, gray-brmn clayey
sand [SC)
.. ,
Trench 20
' , .. w ' - .': $.
.., . ,, ..: .. ... . .. . ,. . . . . ,..... .
Trench 21
Very dense, dmp, gray-brow silty
sand (34)
For Legend, see Figure 4.
r -
LOGS OF TEST TRENCHES 19, 20 AND 21
CARRILLO ESTATES
~~
Project No. 5114 v (~ .2-J-UDo 1: r \ .
G4AlH SIZE lil MILLllfTERS
PUSTICIW C%!RACTERISTICS 1 2 3
Liquid Limit. %
Plasticity Index. % 24 a so
Classification by Unified soil
Classification Systnn CL CL CL
SWELL TEST DATA I 2 3
Initial Dry Density. pcf IC7 I12 105
Initial Water Content. 5 m a 14
160 16C 150
' 9.8 4.7 12.5 Percent Swl I ' -
2.60 SPECIFIC GRAYITY
ZERO AIR VOIDS CUSVES
HOTE:' Spccimen I = S~nple 2-5
Specimen 2 = Sample 3-3
Spcciwn 3 = Smnp~? 11-2
Project 110. 51c Td-UDOl
1000 IW IO 1.0 0.1 0.01 0.m1
GRAIH SIZE IN MILLIMETERS
PLASTICIT/ CHARACTERISTICS I 2 3
Liquid Limit, Hon
Plasticity Index. ;S Plasti :
classification by Unified Soil
Classification System SM
2.60 SPECIFIC GRAVITY
ZERO AIR VOIDS WWES
NOTE: Specimen
Spec inen
Specimcn
%ELL TEST DATA I 2 3
Percent Swell I I
I = Sanple IY-l
2-
3-
.02 .09 a06 -06 0.10 0.12
SHEAR DISPLACWEHT. inches
Keight. inches
Dimeter. inches
0.807
I .9Y
Initial Conditions:
Dry Density. pcf 107.0
Moisture Content. % 13.7
After baking:
I
Dry Density, pcf
bisture Content. %
IC7.8
Surcharge during soaking:
tonslsq.ft.
TEST DATC,
Angle of Friction. degrees
Cohesion. psf 350
I CARRILLO ESTATES t hO0Ch’AX - GIZIENSKI b ASSOCIATES
Height. inches
Diameter. inches
I 0.807
1.99
Initial Ccnditionr:
Dry Dcnsity. pcf
t4oisture Content. 5
I 11.6
9.0
After Soaking:
Dry Density. pcf
Hoisture Content. f
Surcharge during so-k' ~ng:
tons/sq.ft.
114.3,
TEST DATA
Angle of Friction. degrces
Cohesion. psf
NOSHAL STRESS. tonslso. f t .~_~ .. I DIRECT SHEAR TEST
Project NO. 51142N-UD01 f f \
I SWPLE DATA I I Szm2le no: , I1 - 7. 1
Classification:
Height. inches
Dimeter. inches
Initial Conditions:
Dry Density. pcf
Moisture Content. 5
After %?king:
Dry Density. pcf
kisture Content. i,
Surcharge during soaking:
tons/sq.ft.
TEST DATA
Angle of Friction. degrees
Cohesion. psf
Project 140. 5154-2W-UD01
I SbXPLE DATA ~1 1 Sample go: ' 14 - I 1
Classification:
Height. inches I 0.807
Diameter. inches 1.94
Initial Conditions:
Dry Dcnsity. pcf 100.9
Moisture Content. X
After kaking:
Dry Density. pcf
Moisture Content. %
103.3
13.0
Surcharge during soakin3:
tons/sq.ft.
TEST OAT&
Angle of Friction. degre?s
Cohesion. psf 0 -02 -04 .CS .08 .IO .I2 .I4
SHEAR DISPLACWEWT. inches
HORKLL STRESS. tanr/sq.ft. r DIRECT SHEAR TEST
CARR I LLO ESTATES
LUXWARD - GI 2 I &SKI b ASSOCl ATES
COtISULTI!IG %OIL IKD FOUYOATICN ENGISEERS AND GEOLOGISTS 53 DIE,X. CALIFCRWIA
Project NO. 51142W-UD01
Carrillo Estates Units
Slope Stability Analysis
Fill Slope (2 to 1)
Assumptions:
(1) Maximum height of slopes
(3) Unit weight of soil (2) Maximum slope inclination
(4) Apparent angle of internal friction (5) Apparent cohesion
(6) No seepage forces
References :
.~
= 100 ft
c= 450 psf
(1) Janbu, N., Itstability Analysis of Slopes with Dimensionless Parameters,I' Harvard Soil Mechanics Series No. 46, 1954.
(2) Janbu, N., I1Dimensionless Parameters for
November 1967.
Homogeneous Earth Slopes,'1 JSMFD, NO. SM6,
Analyses :
Safety Factor, F.S. = - C Ncf yH Where 'cf is the stability
both c and$. number for slopes with
From Fig. 10 of Reference (2) Ncf = 48
F.S. = 1.7
c-1
..,
Project No. 51142W-UD01
Cut Slope
Assumptions:
11) Maximum height of slopes
12) Maximum slope inclination
:3) Unit weight of soil 14) Apparent angle of internal friction : 5 ) Apparent cohesion
16) No seepage forces
References:
H = 40'
2 to 1
Y = 125 pcf
C = 500 psf
4 = 350
(1) Janbu, N., "Stability Analysis of Slopes with Dimensionless Parameters," Harvard Soil Mechanics Series No. 46, 1954.
(2) Janbu, N., "Dimensionless Parameters for Homogeneous Earth Slopes," JSMFD, NO. SM6, November 1967.
Analyses :
Safety Factor, F.S. = Ncf yH
C Where 'cf is the stability
both c and$.
number for slopes with
From Fig. 10 of Reference (2) Ncf = 22
F.S. = 2.2
c-2
-
. . .. - .. ..
< *' Project No. 51142W-SI01
APPENDIX C
Carrillo Estates Unit 2
Slope Stability Analysis
Cut and Composite Cut/Fill Slopes
(1-1/2 to 1)
Assumptions:
(1) Maximum height of slopes (2) Maximum slope inclination (3) Unit weight of soil (4) Apparent angle of internal friction
(5 ) Apparent cohesion
(6) No seepage forces
References:
~.. ~
H = 20 ft
Y = 125 pcf
C = 300 psf
1-1/2 to 1
0 = 350
(1) Janbu, N., llStability Analysis of Slopes with Dimensionless Parameters,lI Harvard Soil Mechanics Series No. 46, 1954.
(2) Janbu, N., I1Dimensionless Parameters for Homogeneous Earth Slopes," JSMFD, NO. SM6, November 1967.
Analyses :
Safety Factor, F.S. = Ncf- C
YH
From Fig. 10 of Reference (2) Ncf =
F.S. = 2.6
Where 'cf is the stability number for slopes with both c and$.
13
c-3
Project NO. 5~'ZW-UDOl
.- 1.
I, . APPENDIX D
SPECIFICATIONS FOR CONTROLLED FILL
I. GENERAL
These specifications cover preparation of existing surfaces to receive fills, the type of soil suitable for use in fills, the control of compaction, and the methods of testing compac- ted fills. It shall be the contractor's responsibility to place, spread, water, and compact the fill in strict accord-
owner's representative to inspect the construction of fills. ance with these specifications. A soil engineer shall be the
Excavation and the placing of fill shall be under the direct inspection of the soil engineer, and he shall give written notice of conformance with the specifications upon completion
permitted only upon written authorization from the soil of grading. Deviations from these specifications will be
engineer. A soil investigation has been made for this pro- ject; any recommendations made in the report of the soil investigation or subsequent reports shall become an addendum to these specifications.
11. SCOPE
The placement of controlled fill by the contractor shall
isfactory material, preparation of the areas to be filled, include all clearing and grubbing, removal of existing unsat-
spreading and compaction of fill in the areas to be filled, and all other work necessary to complete the grading of the filled areas.
111. MATERIALS
1. Materials for compacted fill shall consist of any mater- ial imported or excavated from the cut areas that, in the opinion of the soil engineer, is suitable for use in con- structing fills. The material shall contain no rocks or hard lumps greater than 24 inches in size and shall contain at least 40% of material smaller than 1/4 inch in size. (Mater- ials greater than 6 inches in size shall be placed by the contractor so that they are surrounded by compacted fines; no nesting of rocks shall be permitted.) No material of a perishable, spongy, or otherwise improper nature shall be used in filling.
2. Material placed within 24 inches of rough grade shall be select material that contains no rocks or hard lumps greater than 6 inches in size and that swells less than 6% when compacted as hereinafter specified for compacted fill and soaked under an axial pressure of 160 psf.
D- 1
Project No. . I, 'd
* *I
3. Representative samples of material to shall be tested in the laboratory by the order to determine the maximum density, content, and classification of the soil.
be used for fill soil engineer in optimum moisture In addition, the soil engineer shall determine the approximate bearing value
other tests applicable to the particular soil. of a recompacted, saturated sample by direct shear tests or
4. During grading operations, soil types other than those analyzed in the report of the soil investigation may be
consulted to determine the suitability of these soils. encountered by the contractor. The soil engineer shall be
COMPACTED FILLS
General
Unless otherwise specified, fill material shall be compacted by the contractor while at a moisture content near the optimum moisture content and to a density that is not less than 90% of the maximum dry density deter- mined in accordance with ASTM Test No. D1557-70, or other density test methods that will obtain equivalent results.
Potentially expansive soils may be used in fills below a
content greater than the optimum moisture content for depth of 24 inches and shall be compacted at a moisture
the material.
Clearing and Preparing Areas to be Filled
All trees, brush, grass, and other objectionable mater- ial shall be collected, piled, and burned or otherwise disposed of by the contractor so as to leave the areas that have been cleared with a neat and finished appear- ance free from unsightly debris.
All vegetable matter and objectionable material shall be removed by the contractor from the surface upon which the fill is to be placed, and any loose or porous soils
plans. The surface shall then be plowed or scarified to shall be removed or compacted to the depth shown on the
a minimum depth of 6 inches until the surface is free from uneven features that would tend to prevent uniform compaction by the equipment to be used.
Where fills are constructed on hillsides or slopes, the
placed shall be stepped or keyed by the contractor as slope of the original ground on which the fill is to be
The steps shall extend completely through the soil shown on the figure on Page 4 of these specifications.
mantle and into the underlying formational materials.
9-2
Project No. 51 2W-UDO1
-4 4, - 1 r
c (d) After the foundation for the fill has been cleared, plowed, or scarified, it shall be disced or bladed by the contractor until it is uniform and free from large clods, brought to the proper moisture content, and compacted as specified for fill.
3. Placing, Spreading, and Compaction of Fill Material
(a) The fill material shall be placed by the contractor in
Each layer shall be spread evenly and shall be thorough- layers that, when compacted, shall not exceed 6 inches.
ly mixed during the spreading to obtain uniformity of material in each layer.
(b) When the moisture content of the fill material is below that specified by the soil engineer, water shall be added by the contractor until the moisture content is as specified.
(c) When the moisture content of the fill material is above that specified by the soil engineer, the fill mat=
or other satisfactory methods until the moisture content shall be aerated by the contractor by blading, mixing,
is as specified.
(d) After each layer has been placed, mixed, and spread evenly, it shall be thoroughly compacted by the contrac- tor to the specified density. Compaction shall be
multiple-wheel pneumatic-tired rollers, or other types accomplished by sheepsfoot rollers, vibratory rollers,
of acceptable compacting equipment. Equipment shall be of such design that it will be able to compact the fill to the specified density. Compaction shall be continu- ous over the entire area, and the equipment shall make
been obtained throughout the entire fill. sufficient trips to insure that the desired density has
(e) The surface of fill slopes shall be compacted and there shall be no excess loose soil on the slopes.
V. INSPECTION
1. Observation and compaction tests shall be made by the
that he can state his opinion that the fill was constructed soil engineer during the filling and compacting operations so
in accordance with the specifications.
2. The soil engineer shall make field density tests in accordance with ASTM Test No. D1556-64. Density tests shall be made in the compacted materials below the surface where
density of any layer of fill or portion thereof is below the the surface is disturbed. When these tests indicate that the
reworked until the specified density has been obtained. specified density, the particular layer or portion shall be
D-3
0 ,,.; Project NO.
- .I
c. C'
I VI. PROTECTION OF WORK
1. Durinq construction the contractor shall properly grade
prevent ponding of water. He shall control surface water to all excavated surfaces to provide positive drainage and
avoid damage to adjoining properties or to finished work on
prevent erosion of freshly graded areas and until such time the site. The contractor shall take remedial measures to
installed. as permanent drainage and erosion control features have been
has finished his observation of the work, no further excava- 2. After completion of grading and when the soil engineer
tion or filling shall be done except under the observation of the soil engineer.
note
NOTES :
The minimum width of 'IB" key shall be 2 feet wider than the compaction equipment, and not less than 10 feet.
The outside edge of bottom key shall be below topsoil or loose surface material.
Keys are required where the natural slope is steeper than 6 horizontal to 1 vertical, or where specified by the soil engineer.
D-4
Project No.
- 1 ' -4 *
APPENDIX E
OVERSIZE ROCK PLACEMENT AREAS (No Scale)
0 Place no oversize rocks in this area.
Oversize rock can be placed in this area.
NOTES
(1) Oversize rocks are those rock fragments between 2 feet and 4 feet in maximum dimension.
(2) Rocks between 2 feet and 4 feet in size should be pro- perly isolated and completely surrounded by properly compacted soil.
(3) No rocks greater than 4 feet in maximum dimension can be used in fills.
(4) The oversize rock should be surrounded by sufficient fines to obtain proper compaction.
(5) No oversize rock can be placed within 4 feet of finish lot grade or within expected depth of utilities, which- ever is deeper.
E- 1