HomeMy WebLinkAboutCT 73-24; CARLSBAD LAKE COMMUNITY; SOILS REPORT; 1981-01-21 (2)•
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Woodward· Clyde Consultants
UPDATE GEOTECHNICAL-INVESTIGATION
CARLSBAD LAKE COMMUNITY
(CARLSBAD TRACT NO. 73-24)
CARLSBAD, CALIFORNIA
prepared for:
piaza ~uilders, Inc.
16800 Devonshire Street
Granada Hilla., California 91344
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3467 Kurtz Street
San Diego, California 92110
714-224-2911
Telex 697-841
January 21, 1981
Project No. 50316W~UDOI
Plaza Builders, Inc.
16800 Devonshire street
Woodward-Clyde Consultants
Granada Hills, California 91344
Attention: Mr. Ed Hamner
UPDATE GEOTECHNICAL INVESTIGATION
CARLSBAD LAKE COMMUNITY
(CARLSBAD TRACT NO. 73-24)
CARLSBAD, CALIFORNIA
Gentlemen:
In accordance with your request and our proposal dated
December 2, 1980, we have prepared an update report of the
soil and geologic conditions on the subject site. This
conforms to Phase I of the studies presented in our pro-
posal.
SCOPE AND PURPOSE OF STUDY
Our study consisted of reviewing our ~iles concerning
the site, making a field reconnaissance and reviewing up to
date applicable geologic literature. The purpose of this
work was to provide a basis for our report and to provide
cr i teria for development of the site i.ncluding-conclusions
and recommendations regarding:
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The possible presence of geologic hazards on the
site,
The stability of proposed cut and ~'ill slopes,
Foundation design, including allowable soil
bearing pressures in natural ground and compacted
fill, and,
EarthWork and grading specifications.
Consulting Engineers. Geologists
and Environmental Scientists
Offices in Other Principal Cities
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Plaza Builders, Inc_
January 21, 1981 '. ,
project No. 50316W-UDOl
Page 2
PREVIOUS SOIL STUDIES
AO'
Woodward· Clyde Consultants
A preliminary soil investiga,tion of the site was
prepared by Woodward-Gizienski and ,A.~sociates. The results.
of that study were issued in a report entitled "Soil Investi-
gation for the Proposed' Carlsbad Lake Community, Carlsbad,
California," dated July 30, 1973. A. copy of that report is
attached (Appendix A) .
DESCRIPTION OF PROPOSED PROJECT
The subject site is east of Interstate 5 and south of
Poinsettia Lane in Carlsbad, California. For our study, we
were provided a copy of "Plot ana Grading Plan, Carlsbad
Tract No. 73-24," prepared by Lawrence R. Williams Consulting
Civil Engineer dated August 5, 1974 with latest revision
dated June 14, 1976. Except for minor changes this plan is
essentially the same as that studied for the 1973 Woodward-
Gizienski & Associates investigation.
The plan indicates that the site will be graded to form
building pads for construction of 67 multi-story condominium
type structures. The plans also indicate that cut slopes
will have maximum heights on the order of 15 feet and slope
inclinations of 2 to 1 and that fill slopes will have maxi-
mum heights on the order of 25 feet and 15 feet with slope
inclinations of 2 to 1 and 1-1/2 to 1, r.espectively.' The
1-1/2 to 1 inclined fill slope is proposed along the western
property line approximately 30 feet east of the top of an
existing 2 to 1 inclined cut slope extending down to Inter-
state 5. This existing cut slope has a m,aximum height on
the order of 30 to 40 feet.
The plans also indicate that two shallow, on the order
of 4 feet deep decorative ponds will be constructed in the
central portion of the site.
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Plaza Builders, Inc.
January 21, 1981
project No. 503l6W-UDOl
Page 3
CURRENT SITE CONDITIONS
. Woodward· Clyde CQnsultants
The site is located on a r'elatively flat north-south
trending ridge. The ridge top slopes gently to the west.
The major portion of the site has been cultivated to depths'
of 1 to 2 feet sometime in the past. These cultivated
topsoils consist of silty to clayey sands. Underlying' the
topsoils are the Quaternary age L,indavista Forma.tion a.nd the
Eocene age Santiago Formation. A review' of the' g'rading
plans and our field reconnaissance indicates that all pro-
posed cuts will be in the Lindavista Formation. These
materials are dense to very dense silty to clayey sands.
As noted in the 1973 report,a small area of uncompacted
fill was found in the west-central portion of the site.
This fill extended to a depth of 13 feet and consists of
silty to clayey sand. No new fill was noted on the site.
Man-made structures on the site consist of a waterline
(shown on the plans) present along the eastern site boundary
and a sewerline (not shown on the plans) present along the
western site boundary. Although· not observed during our
site reconnaissance, abandoned irrigation lines may be
present.
Vegetation consists of a dense growth of native weeds
and grasses.
GEOLOGIC HAZARDS
Faulting
For this study we have reviewed our files and published
literature including the "Geology of the Encinita.s Quadrangle,"
prepared by Kenneth Wilson in, 1972. The review' did not
indicate the presence of any known faults on the site, nor
was any surface evidence of faulting noted on the ~ite or
the ridge side slopes during our site visit.
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Plaza Builders, Inc.
January 21, 1981
Project No. ·S03l6W-UDOl
Page 4
Woodward-Clyde Consultants
The nearest known active fault along which seismic
events of Richter Magnitude 4.0 or greater have been re-
corded is the Elsinore Fault zone, mapped approximately 25
miles northeast of the site. The hypothesised northern
extension of the Rose Canyon Fault zone is located approxi-
mately 5 miles west of the site. No earthquakes greater
than Richter Magnitude 4 have been recorded for this fault.
Landslides
In addition to other work previously mentioned, our
evaluation of the potential for landslides included re-
viewing aerial photographs and general topography of t4e
site. No landslides or landforms that could be construed as
landslides were noted.
Ground Water
No water seeps or springs were noted during our recent
site visit. No ground water was encountered in the test
borings made for the 1973 investigation. We do not expect
that a ground water table is present within proposed grading
depths.
DISCUSSIONS, CONCLUSIONS, AND RECOMMENDATIONS
The discussions, conclusions, and recommendations
presented in this report are based on results of our field
studies, analyses and professional judgment.
The results of our field reconnaissance, made by a
senior staff geologist of our firm on January 7, 1981,
indicates that the site is in essentially the same condition
as it was for the 1973 field investigation, although no
actual surveying was done.
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Plaza Builders, Inc.
January 21, 1981
Project No. 50316W-UDOl
page 5
Potential Geologic Hazards
Wf?odward-Clyde C~nsultants
Faulting -Our investigation identified no faults
crossing the site.
Seismicity -All faults have a potential for earth-
quake activity. The fault zone closest to the site along
which earthquakes of Richter Magnitude 4 or greater have
been recorded is approximately 25 miles from the site,
whereas the closest significant faulting to the site is
approximately 5 miles from the site but this fault has not
exhibited earthquakes greater than Richter Magnitude 4.
Liquefaction Potential -We estimate that the depth to
the regional ground water table is in excess of 50 feet. In
our opinion, this depth, together with the dense nature of
the soils on the site generally precludes the possibiiity of
liquefaction.
Landslides -Our field investigation and review of maps
and vertical'aerial photographs disclosed no evidence of
landslides on the site.
Ground Water
In our opinion, no shallow permanent ground water table
exists on the site and the conditions of the proposed
development indicate a low probability of ground water seepage
problems resulting from existing subsurface water.
We recommend that positive measures be taken to prop-
erly finish grade the building areas after structures and
other improvements are in place so that'drainage water from
lots is directed off the lots to the street and away from
foundations, floor slabs, and slope tops. Even with these
provisions, experience has shown that a shallow ground water
or surface water condition can and may exist in areas where
no such ground water condition existed prior to site develop-
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plaza Builders, Inc.
January 21, 1981
Project No. 50316W-UDOI
page 6
W~odward.~IYde -Consultants
ment. This is particularly true where a substantial in-
crease in surface water infiltration results from landscape
irrigation.
Slope Stabil·ity
For the proposed slopes we have performed stability
analyses using the Janbu method of analyses and the follow-
ing soil strength parameters:
Area %' :, C" :(p's:f) y,(pc:f}
Cut Slopes
Fill Slopes
300
250
125
120
These parameters are based on laboratory tests per-
formed for the 1973 field investigation report and our
experience with similar soils in nearby areas.
Our analyses indicates the proposed slopes w.ill have
calculated factors of safety in excess of 1.5 under static
conditions for both deep-seated and shallow sloughing.
Stability analyses require the use of soil parameters
selected from a range of possible values, thus, there is a
finite possibility that slopes having calculated factors of
safety as indicated above could become unstable. In our
opinion, the probability of the slopes becoming unstable is
low and it is our professional judgment that the slopes can
be constructed as planned.
He recommend that all slopes be planted, dra.ined and
properly maintained to help control erosion. Our expe~ience
indicates that slopes constructed at steeper than 2 to 1 are
particularly susceptible to shallow slope sloughing during
periods of heavy rainfall, heavy irrigation or. upslope
surface runoff. Periodic maintenance, including the re-
building of the outer 18 to 36 inches of the slope, may be
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Plaza Builders, Inc.
January 21, 1981
Project No. 50316N-UDOl·
Page 7
Woodward· Clyde Consultants . . .
required. Sloughing of fill slopes' can be reduced by
overbuilding the slope by at least 3 feet a.nd cutting ba.ck
to the desired slope inclination.
Sloughing can also be reduced by backrolling slopes at
frequent intervals. We recommend' that a.ll fill slopes be
backrolled at least every 4 f'eet of f'ill heig'ht a.nd tha.t. 2
to 1 inclined fill slopes be trackwalked upon completion.
Earthwork
We recommend that the site be graded in a.ccordance with
the attached Specifications for Controlled Fill (Appendix
B). 1;\Te also recommend that the grading be observed by and
compacted fills be tested by Woodward-Clyde Consultants.
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.
We recommend, in areas to receive new fill or structures,
that the existing fill and underlying porous topsoil in the
west-central part of the site be excavated, watered as
required and compacted. The 1973 repor.t indicates the maxi-
mum combined depth of exis.ting fill and por.ous topsoil is
on the order of 13 feet, however, we recommend that the
actual depth and extent be evaluated in the field at the
time of grading.
We recommend that all other loose a.nd/or cultivated
topsoils not removed by planned grading operations be ex-
cavated, watered as required, and compacted prior to placing
additional fill or structures.
Although no expansive soil were noted during either the
1973 or current investigations, our experience in nearby
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Plaza Builders, Inc.
January 21, 1981
Project No. 503l6W-UDOI
Page 8
Woodward·Clyde Consultants
areas indicates that residual clayeY. soils may be ·en-
countered locally beneath the topsoils. If expansive clay
soils are found during grading, we recommend that they be
excavated where encountered, a. minimum depth "of 2 feet beTow
rough grade in building areas and 1 foot in pavement areas.
The building area is defined a.s the area of the building
plus 5 feet beyond the building limits. The clay soils can
be replaced with properly compacted nonexpansive g"rgnular
soils available on the site.
We recommend that the upper 2 feet of fill in building
areas and I foot in pavement areas be composed of properly
compacted nonexpansive granular soil available ·on the site.
We recommend that all cut areas be examined by our
firm during grading to evaluate actual geologic conditions.
Foundations
He recommend that foundations for the proposed build-
ings founded in either undisturbed or properly compacted
nonexpansive materials be designed for an allowable soil
bearing presure not exceeding 2,000 psf (dead pluS live
loads) at 12 inches below compacted fill or undisturbed cut
lot grade. In our opinion, this soil bearing pressure can
be increased by no more than one-third for loads that in-
clude wind or seismic forces. We recommend that all con-
tinuous footings have minimum widths of 12 inches.
We recommend that structures that cannot tolerate
differential settlements (foundations, floor slabs, decks,
etc.l not be located within 8 feet of the f"ace of a slope.
For structures located in this zone we recommend the ~oot
ings be extended in depth until the outer bottom edge of" the
footing is at least 8 feet from the face of the slope.
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Plaza Builders,. Inc.
January 21, 198·1
project No. 503l6W-UDOl-
Page 9
Woodward·Clyde Consultants
Recommendations for pond construction are not within the
scope of this report. Recommendationa in this regard can be
presented in an addendum report upon request.
RISK AND OTHER CONSIDERATIONS
We have only observed a small portion of the pertinent
soil, and ground water conditions. The recommendations made
herein are based on the assumption that soil conditions 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 recommendations presented herein has been properly
interpreted and incorporated into the contract documents.
We further recommend that the geotechnical consultant
observe the site grading, subgrade preparation under con-
crete slabs and paved areas, and foundation excavations.
It should also be understood that California, including
San Diego, is an area of high seismic risk. rt is generally
considered economically unfeasible to build totally earth-
quake-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 con-
struction, and partly on our general experience in the
geotechnical field. Our engineering work and judgments
rendered meet current professional standards. We do not
guarantee the performance of the project in any respect.
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Plaza Builders, Inc.
January '21, 1981
Project No. 503l6W-UDOl
Page 10
Woodward· Clyde Consultants
This firm does not practice or consult in the field of
safety engineering. We do not direct the contractor's
operations, and we cannot be responsible for the sqfety of
other than our own personnel on the site; therefore, the
safety of others is the responsibility of the contractor.
The contractor should notify the owner if he considers any
of the recommended actions presented herein to pe unsafe.
If you have any questions, or if we can be of further
service:;, plea:se g'tive us ,a call.
Very truly yours,
WOODWARD-CLYDE CONSULTANTS
Richard P. While
R.E. 21992
RPW/DS/MRR/rs
Attachments
(4) Plaza Builders, Inc.
(4) Lawrence R. Williams Consulting
Civil Engineer
~~ paryl S.treiff
C.E.G. 1033
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APPENDIX A
REPORT DATED
JULY 30, 1973
Woodward· Clyde Consultants
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July 27, 1973
Project No. 73-222
Covington Brothers .
2451 E. Orangethorpe
Fullerton, California 92634
Attentioil: ~1r. Mike Ryan
CARLSBAD LAKE Cm{li~UN lTY
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In accordance with your request we have provided geologic and engineering
services for the proposed Carlsbad Lake Community in Carlsbad, California.
The services provided incl~de subsurface borings and a geologic reconnais-
sance, and a review of available literature pertaining to possible geologic
hazards which may occur in the vicinity of the subject site. A report of
the field investigation is forthcoming.
Our field investigation and review of pertinent 1iterature indicate there
are no active faults within the subject site and that no major adverse
geologic conditions exist which would preclude further development of the
site.
If you have any questions in this regard, please call or write at your
convenience.
I>JOom'IARD-GIZIENSKI & ASSOCIATES
-f2.1-/} ~-J_/. f!. ~Vk/.1.--z.""-<1 .e~ if"l·,...·.t1 l/\>~~..:.A:.....
Stanley F. G7zienski, R.E6I10352
SFG/f·1RR/mf
(4)
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SOIL INVESTiGATION FO~ THE PROPOSED
CARLSBAD LAKE. COMMUN DY'
CARLSBAD, CALIfORNIA
for
Covington Brothers
2451 t. 'Ora.ngethorpe .
Full erton; '~a li'forn ia 92634
by .
WOOD~·jARD-GIZlENSKI & ASSOCIATES
Consulting Soil and Foundation Engineers and Geolpgist . ."
(An Affiliate of Hood~·rard-Clyde Consu'1tants)
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TRANsr·1ITTAL LETTER
SCOPE
FIELD INVESTIGATION
LABORATORY TESTS
TABLE OF CONTENTS
SITE AND SOIL CONDITIONS
CONCLUSIONS AND RECO~1MENDATIONS'
L UlITATI ONS
FIGURE 1 ~ SITE PLAN
FIGURE 2 -LOG OF TEST BORING l'
FIGURE 3 -LOG OF TEST BORING 2
FIGURE 4 -LOG OF TEST BORING 3
FIGURE 5 -LOGS OF TEST BORINGS 4 & 5
FIGURE 6 -LOG OF TEST BORING 6
FIGURE 7 -LOG OF TEST BORING 7
FIGURE 8 -LOGS OF TEST BORINGS 8 & 9
FIGURE 9 -LOGS OF TEST BORINGS 10 & 11
FIGURE 10.-LOGS OF TEST BORINGS 12 & 13
FIGURE 11 -LOG OF CUT SLOPE
FIGURE 12 -GRAIN SIZE DISTRIBUTION CURVES
FIGURE 13 -RESULTS OF CONFINED COMPRESSION TESTS
FIGURE 14 -FILL SUITABILITY TESTS
ATTACH1·1ENT I -SPECIFICATIONS FOR CONTROLLED FILL
ATTACHMENT II -FILL SLOPES: STABILITY ANALYSIS
ATTACHr~ENT III -CUT SLOPE: STABILITY ANALYSIS
PAGE
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WOODWARD· GIZIENSKI & ASSOCIATES
COHSUl:TlHQ SOfL AND fOUNOATlON [N<;'H[tltS AND CE:9LOCISTS
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July 30, 1973
Project No. 73-222
Covington Brothers
2451 E. Orangethorpe
Fullerton, California 92634
Attention: Mr. Mike Ryan
In accordance with your Purchase Order Number 15290 and our proposal dated
June 4, 1973, we have conducted an investigation of the underlying soil
conditions at the site of the proposed Carlsbad Lake Communjtysubdivis.i6n
in Carlsbad, California.' '.' '0
Results of our studies indicate that the site is suitable for the proposed
construction. There are hov-Jever, existjng.fills, porous soils, and cultivate.d
soils existing on the site that will require special treatment during grading.
The accompanying report presents our conclusions and recommendations, as well
as the results of the subsurface exploration and the laboratory tests upon
which these recommendations are based.
The engineer assigned to this project was Joseph G. Kocherhans of our firm.
WOOm,jARO-GIZI ENSKI & ASSOCIATES
~,dt~"F~~
Stanley F. Gyzi.enski, R.V' 10352
SFG/JGK/ls
(6)
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Project No. 73-222
SCOPE
This report describes an inves~igation of, the underlying soil and
geological conditions at the site of the proposed Carlsbad Lake communi"ty 'to
be located east of Interstate 5 and south of Poinsettia Lane, in Carlsbad,
California. The purpose of the investigation is to determine the general
geology and subsurface conditions" including the presence and effect of
existing fills, loose or porous soils, and potentially expansive soils; the
embankment shrinkage facto~; the relative stability of cut and fill slopes;
the availability of,select fill materials; recommendations regarding allowable
bearing pressures fo~ deSign of foundations' in natural ,undisturb~d soil and
in compacted fill; the most suitable type and required depth of foundations.
for use at the site; and, t~e depth to water, if significant.
It is our linderstanding the dev~lopment will consist of approximately
300 one to two-story wood-frame condominiums utilizing concrete slab-on-grade
constructi on.: ,We also understand that a shallow 1 ake wi 11 be excavated at
the central portion of the site. It is our further understandin~ that grading
will be performed in general, in accordance with the TentatiVe Tract 73-24
plan dated May 1973, prepared by Lawrence R. Williams, Tustin, California,
Consulting Civil Engineer.
FIELD INVESTIGATION
Thirteen test borings were made by a truck mounted, ,continuous
flight, 6-in. diameter power auger and one existin~ cut slope was logged at
the approximate locations shown on the Site Plan, Fig. 1. Field and sub-
surface exploration was done on July 5 and 7, 1973, under the supervision of
a staff engineer from our firm. Field logs were prepared by the engineer on
the basis of an inspection of, the samples secured, the materials excavated,
and the soils exposed in the eXisting cut bank along Poinsettia Lane.
WOO D \'I A RD· G I Z IHI SKI & ASS 0 CI ATE S
CONSULTING SOIL AND rOUNOATlOH [NGIN((Pt$ AHD G(OlOCISrs
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Project No. 73-222 P.age 2,
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The. ~~gs of the Test Borings are shown on Figs. 2 ·through 10 and are
based on an inspection of the samples taken, the laboratory test results
and field logs. Test Boring locations were· plotted in the field on a Site
Pl an enti tl ed IITentative Tract 73-24 Carl sbad Lake Communityll dated May T~73,
and prepared by Lawrence R. vJilliams of Tustin, California.
LABORATORY TESTS
The soils encountered were visually classified and evaluated with
respect to strength, swelling and compressibility characteristics, dry
density and moisture content .. These classifications were SUbstantiated by
moisture content and dry density, ·plasticity, grain size analysis, direct
sh.ear and confined compression tests on representive samples of the soils.
Results of the moisture content, dry density, plast.icity and direct shear
tests are shown at the corresponding sample location on the Log of Test
Borings. Results of the grain size analyses and confined compression tests
are shown on Figs. 12 and 13, respectively.
Fill suitability tests, including compaction, grain size analysis,
and direct shear tests have been performed on the probable fill soils •.
Results of the fill suitability tests were utilized to arrive at the conclusions
and recommendations contained herein and are presented on Fig. 14.
SITE AND SOIL CONDITIONS
The site is located south and east of the intersection of Interstate 5
and Poinsettia Lane and west of Bataquitos Lane in Carlsbad, California. The
site consists of a relatively flat north-south trending ancient IIbeach ridgell
sloping gently to the west with changes in elevation from approximately 150 ft
in the east down to approximately 110 ft near 1-5. A relatively steep
(approximately 2 to 1, horizontal to vertical) somewhat eroded slope exists
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near the eas tern boundary. The Tentat; ve Tract Pl an ; ndi cates that cons tructi on
WOODWARD· GIZIEr-ISKI & ASSOCltHES
C.oNSOLTlHG SOil AND FOUNDATIOH (NGIN(~R!. AND GEOLOG.ISTS
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will be limited to the gently sloping western portion of the site. At the
time of our investigation the major portion of the site was under cultivation.
A row of large eucalyptus trees trending north-south exists in the north-
western portion of the site.
Results of the test borings made at the site indicate the presence
of the following materials which are described in their general order of
occurrence with depth and increasing geological age.
Fill. Damp to moist, brown silty sand with a trace of clay.
The fill was encountered in the west-central portion of the site
in Boring 7 extending to a depth of 13 ft. Piles of loose fill
have been placed along ~he top of the ridge near the eastern
boundary of the site. Some rubble and organic materials were
observed in the scattered piles of fill in this area .
. T.opsoi 1. Loose to medium dense, genera'lly porous, damp to
moist, dark brown silty sand. This material was encountered in
borings located in the western portion of the site, Borings 1,2, and
8 to 13, ranges from one to six ft in thickness. These topsoils
exhibit low potential expansibility characteristics~
Terrace t1aterials. Medium to very dense, damp, red brown to
grey brown silty to clayey sands. These materials were encountered
in all borings and extend to the depths explored, a maximum of 30 ft.
They comprise the basic formational soil at the site, and relatively
competent foundation material and exhibit a low potential for
ex~ansion when wetted.
Below the fill found in Boring 7 abo~t 4 ft of porous c'ayey sand
"old topsoil" was encountered.
No hard rock or ground water was encountered in the test borings
at the time of excavation .
WOODWARD· GIZIENSKI & ASSOCIATES
CONSULTING $OIL ANO fOUNDATION ( .... CUU(~5 AND C{OlOClSTS
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Project No.'73-2g~ " P,age 4
CONCLUSIONS AND RECOMMENDATIONS
(1) It is our opinion no'major/soil conditions exist at the site
which would preclude the devel~pment of the proposed one to two-story
condominiums. The presence of existing fills, old porous topsoil, and loose
piles of trashy fill will require special treatment du~ing grading.
(2) The' ground whi ch will rec~ive fill and/or one and two-story
condominiums will have an adequat~ bearing value to safely support the
proposed loads when treated as described fn the following paragraphs and
in the attached "S pecifications for Control1ed Fill". Footings for
residential structures placed on nonexpansive, non-porous ,native soils or
properly compacted nonexpansive fi 11 soil s may be desi gned for a soi 1
bearing pressure of 2000 psf (total dead plus live load) at a,depth of'12
inches below rough lot grade. Footings should have a minimum width of
12 inches. The above soil bearing pressure may be increased bY,one-third
for loads that include wind or seismic forces.
(3) Cut and fill slopes having an inclination of 2:1 (horizontal
to vertical) and maximum unsupported heights of less than 25 feet will in
our opinion have adequate safety factors against deep s·eated slope failures
if cons tructed in accordance Itli th the plans and the attached "S peci fi cat; ons
for Controlled Fill". Typical stability calculations for cut and fill
slopes are attached for your information to support our conclusions.
(4) Results of our field investigation indicate that soils
expected to be used in fills are basi~ally nonexpans;ve. Though no potential
expansive soils were encountered, it has been our experience, that thin
(1 to 2-ft) residual clayey soils could be encountered between the topsoils
and formational soils in localized areas. Should any potentially expansive
soils be encountered they should be excavated and spread and compacted in
WOODWARD· GIZIENSKJ & ASSOCIATES
CetdUl TlHQ SOli .. ANO rOUNDA nON lHGU'~£lIt' AHO C[OLOGIS'TS,
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fills below a depth of 2 ft bel<M rough lot grade. Potentia1lyexpansive
soils, if encountered within 2 ft of finish grade in cut areas should
be undercut and be replaced with properly compacted nonexpansive ~oils
available on the site.
(5) Results of our field exploration indicate that all materials
encountered can be excavated with normal heavy grading equipment. No
extensive cemented zones nor hard rock are expected. '
(6) , In order to express a meaningful estimate of the embankment
shrinkage-swell factor, the results of labor,atory compaction tests need
to be compared to the density in the natural state in borrow. We, wish
to emphasize that variations in soil d~nsity in the natural state, as w£11
as, in the fill, make cal cul ated values of, shri nkage at best very approximate.
A major factor is that relatively few tests are made of on-site materials
as compared to the mass of material moved'during grading plus the inSUffi-
cient knowledge regarding the actual densities in ex.cess of minimum require-
ments to which the contractor will compact the fill. Based on the limited
work done to date and considering the above factors the following shrinkage
values for preliminary estimating may be used: Topsoil, approximately
, 8% + 2%; the underlying formational soils approximately + 2%; existing
loose fills, 10 to 20%.
(7) O~r experience with soils similar to those encountered
on the site indicates that they could have relatively high permeability
rates. Therefore the water loss through seepage of the proposed lakes
could be high, could cause marshy areas at lower elevations, or could show
as slope seepage. It is therefore recommended that adequate steps be taken
to seal the lake areas or to intercept the seepage so that no harmful
effects resul t.
WOODWARD" GIZIEHSKI. & ASSOCIAT[S
CONSULTING SOIt .. AND 'OUNOAT!OH [NCIN{[Jt, AND CLOlOCIS1J.-
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(8)
~ , : ' ' ~ .. : i (. : ... • • ~I ... •• ': "'-1 •
, '. " '. '" '.0", , " J
Soils similar to those encountered ·on this site ar.e subject
to extreme erosion by uncontrolled action of water. Therefore, it is
recommended that all cut and fill slopes be planted and be provided with
adequate surface drainage in accordance with the City of Carlsbad standards.
(9)· It is recommended that loose and/or porous soils as well as
existing fill soils that are not removed,by grading operations be excavated
or scarified, as required, replaced and compacted before fill or structures
are constructed. Iri general the loose and/or poro~s su~face soils average
approximately 3 ft in thickness where encountered: The maximum thickness of
existing fill encountered was approximately 13 ft at Boring 7. Since the fill
soils on the site have the same general appearance as the formational soils
and the area is used for plant growth, it is difficult to define exact limits
of existing fills for this report. The former erosional patterns are not
known by us. nor is the extent.of filling to make grade for the present
farming oper~tion. Because of these factors it is recommended that several
inspection pits be made with grading equipment at the time of grading in
proposed fill areas to ascertain the extent of existing fills.
(lor It is recommended that all existing potentially compressible
soils be excavated, as required, and compacted prior to placing fill soils
or structures. This recommendation includes the area of porous old topsoil
in the vicinity of Boring 7. The excavation is expected to extend to
approximately 16 ft in depth (the depth to the ba~e of the porous soils in
Boring 7). Since there has been some filling on the site in the past, the
actual extent of porous soils that will require treatment should be controlled
in the field by the soil engineer during grading upon visual examination of
the exposed soil.
WOODWARD· GIZIENSKI & ASSOCIATES
COI-ISUlTlNG SOIL ANO rOUNOATIOH (N(;,f'4[[ltS AND G(OLOGISTS
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(11) It is recommended that all grading operations be observed
and compacted fills tested by Woodward-Gizienski & Associates. Organic
material and debris should not be permitted in compacted fill. A set of
"Speci fi cati ons for Contra 11 ed Fi 11" is attached. The recommendations
made as a part of this report shall become a part of the "Specifications
·for Controlled Fill".
LHlITATIONS
The conclusions and recommendations made in this report are
based on the ~ssumption that the soil and geol~gical conditions do not
deviate appreciably from those disclosed by the test borings. If
variations are encountered during construction, we should. be notified so
that we may make supplemental recommendations, if this should be required.
Evaluation and utilization of soil materials and geological
formations 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 excavati~ns or cut slopes so that he
can make the necessary modifications, if needed. We emphasize the im-
portance of the soil engineer continuing his services through the inspection
of grading, including construction of fills, and foundation excavations.
WOOD VI A R D ·G I Zl ENS K I & ASSOCIATES
CONSULTlHG sOll;-AND fOUrtOAT10H tNGIH([KS ANQ I?£OI..O<;'ISTS
• • • • • • • •
;~)~~
r',"'"",:",\'::'~~~--
/ J " '. , ~ 1211 "" """ -,\---, ''------,-'--",----
. :~
~. i.
f
~ 'M'
I;
"
!
\
~' "", " " ~~
lZ -3-'\>\' '----'~.------:.:~=~----~=~~-,oo S-I~ ,q.,, __ \,,-,_--:-__________ . ________ :'~r-~_,.o
1 • ,-' -----______ ~--_ '-'-___ ---, , ~property i:' -------/50 -______ ,-~~~-:_ ~ ---.---------"<~-__ ",1 -------------------------------_ .. __ ... ' "'-1"10 ~ -'~i' Ii
t.j· ,i ...... ~: ~!II " -------________ _
1 " 100 F---,-90
................. '---., ;.-I;;, ____ ----~----,-'---:-------;,/',-".:.,-,~-\-'_____ -'-,-----------------... -..../ Vs '--__ -,-__ ---' ~---:----,---___ "'..' ... ,
"r /; "'" ""':: ~," ',--, ''', >, ----,,"-----,", ,," --, "--""_,:"" _______ ,, ,,',' __ ---->'''''~:: ,:_''' ___ :'~>:~~:-:?~"<>'\ ~J'----'"0", __________ " ~/q'l.~:O-:---:..---:------~: ... ---=.','----:::;...-~--___ "::
t ' '[' ~13.' ' _____ :-_ "", ' ___ ,,\ ',~, " --y ~ 12 -.', \ \ \ --------y 411 ", \ \ \60 n~, _ -------------------------______________ "\ \,\/So
, 2:::~1,'k ~ --------:~---""----'~;~:~~ __ ,~:~~:~;::~~:::~~:=:::--~:;:----,--~~ {> ):::~
;-;:::: ---->-------:7~-!-o~~~~:a-t~-:-------------~:~--:i-e-g~---:~::ay
LEGE,~D:
-1-Indicates approximate location of Test Boring.
"Ir.;jjcates api'roximate location of Cut Slopeo
.... ··-···.lndicates approximate ground surface contour&o ri Indicate. approximate ! I~ita of fill and porous L~'~Jnaterial.
Graphic Scale (feet) ,
250 0 250 500 750 ~ • .. ---====s
SITE PLAN
CARLSBAD LAKE COMMUNITY
hQODt~ARD -G 1Z /Et;$K 1 & !ISS:;;: I n ~ES
CONSULTING SOIL ANO rOUN~ATION E~3INEEoS AhD G£CLO:;ISTS S~N DIEGO. CALIfORNIA
'"' I ,0· 7~222
". 0 BY' :-: ;.'1:: Iit.~:
1".:.:-
, ~! i~ ~·f .
.... " :~
I
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1
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•
•
•
•
•
•
•
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•
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ll .... ~A., .... ,,' -----", ...... ~
if
/ ,I I
tamn ...• II':; :
f
j
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:1 ;:
'I • j
~ II ~ ~ ~ ~ ~ ;j
OJ I" I~ ;J ~ ~,
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d l
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~ ~ ~ 3 ~ 'I ~ ~ 1
·1 • 'J ~ 1 ~ ~ 4 ~ " ,J
,1
1
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(!) co
0-
5-
10-
15-
20 -
Bor i ng
------~-~~r_------------------------__ ___
\','C = 5 l-!-J I Medi urn dense to dense, damp, bro..,,, ~g ~ I ~6 J 3 Ii' s i Jty sand (~,i)
we = 9
DD = 120
Be::: 32
n... _ "'" -
_.
}1r-",: t,iedi urn dense to dense, damp, red-
brown c J ayey sand ( SC)
~: .-.:
ye J J ow-brol'/il s i J ty sand
damp, red-bro\\'11 S i 1 ty
.; "
,:.::::";':: ...... :: ....... ' .. -.:.: . ...... :
I~" Be = 4D/SII C':::::' :~------------------------------
For Legend, see Fig. 3 LOG OF TEST BORI NG I
1 CARlSBAD LAKE COMMUUITY 11 , 1 ~.C'()Dt-JARD -GIZI8JSKI & ASSJCIATES I
J CO:IWLHWG SOIL I...~O rOU:iD.HlC:1 E}:GIt:E~i\,S A.1l0 G£OLOulSTS I
l S,~:l 01 ECD. CALI FO,\,iIA . ,. 1
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Q) cc
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+J
0-
Q) o
0-
5-
10 -
15-
Bori ng 2
Loose, damp, bro\,111 si lty sand (SM)
Be =
Be= 68J·j0L·I----------~----------
LEGEND ..
WC = water Content in percent o~ dry weight"
DD = Dry Density in pcf"
BC = Humber of blows by 1'40-lb" hammer fall ing
30 inches to drive sampler 12 incheso
Sampler Data: ID = 2.0", 00 = 2.5"
OS = Direct Shear Test Data:
¢ = Angle of Apparent Friction in ~egreeso
C = Apparent Cohesi6n in psf"
(SM) = Group classification symbol in accordance with the
Unified Soi I Classification System"
Sample Humber
=r . .
J i
t i I I 1 I
I, ,
f
I I r t !
! i f \-
I
I' ,I 'I I, ·1
II
/' d Ii .I I -,
I 'I
II
I, I! I i
•
•
•
•
•
•
•
•
•
•
•
<:J c:
:J o L-a
3: o
C) co
o
5
10
15
20
25
30
I '. Be = 34/6" !
3 . ~
..... 'Ii
Bor i ng 3
Very dense, damp, red-brown clayey
sand (SC)
}
I' Slightly Porous ~g ~ II ~ 2 n :'.-'
Be = 327ft [I'
,_ .' ~,~c' Very dense, da"p, red-brewn to ~g ;; III ~r ':."." yellow-brown si ltt sand (S,1)
Be = 38/6" .. : .... : '.:.,:'':: ,. ...... ,~.
we = 3 DD = 97 BC = 35/6" 5 DS: ~ = 36 C := 200
BC = 68
...... :
.. ::.::.:.
.~----------------------------" .. :~. Very dense, damp, gray-brO\"ffi si lty
<,} sand (SM)
. ~:
Be = 66 B" ~~--------------------------------
For Legend, sec Fi g. 3 LOG OF TEST BORING 3
CARLSBAD LAKE CQ·I/,lUNITY
, '"' I
I
I'
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•
•
•
•
•
•
iJ .:
'\ ~ • I ,
~
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3: o
Q)
CO
eM ln PH'
'0 -
5 -
10 -,
15 -
o -
5 -
10 -
15 -
Bor i ng lJ.
IIC = ~ I I [)ense to very dense, damp, red-bro..." gg~ 14~ ' .. clayey sand (SC)
'. ~ S1 ightly Porous
DD = III ,'. VlC= n2 .
BC = 35 ,., : ....
BC = 7¥tJlJ
gray-brol"n s i 1 ty
BC= 6~ I~'_":~~ ______________________ ~~ __ _
Bor i ng 5
WC =!Jl 51::: '::,' Dense, damp, red-brol-'.'fl clayey sand
DD = 109 I . (SC) BC = 24-"
I-Sl i ght 1 y Porous
tiC = 6Ull DD = 117 ..
BC = ~I DS: {) = 29
C = 320 :.:
BC = 50~
BC= !j.2Jr-~-L __________________________ __
For Legend, sec Fig. 3
I f i
I I I
II
I
•
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•
•
•
•
•
•
(!)
CD
..c: +'
0-
(!)
Q
o
5
10
13
; ~I.:. ..' ......
'" -
Bor i ng 6
we = ~ .... . DD = 126 I ... .
Be = 35 t-
. .':-. :~
;:.':.:.:
Be =
--::"'.'
Dense to very dense, damp, red-bro~m
clayey sand (SC)
I I·
•
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•
•
•
•
•
•
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•
•
+' Q)
Q)
l.J...
3: o
(j)
In
..c
+' 0.. (j)
Cl
0-
5 -
10 -
15 -
20 -
Bor i ng 7
we = 7 ~ Damp, dark bro~1n silty sand Fi 11 DD = I Ill-~-+-_-=-=.:.:L..I.--=-~--'-:"":":"--'--=--~--,--,-_--=--,--_
Be = Ill-Damp, red-brown si lty sand Fi 11
-3 --\'Ie = 8 2
DD = 106 I--
Be = 12
-
. -we = II lI-
DD = 112 f--
Be = 37
-
-
Darnp to moist, ye110l·;-bro.:Jn to
red-brOi'lTl silty fine sand
Fi 11
~~dium d~nse, da71p, red-brown clayey
sand (SC) Porous (Appears to be topsoil)
For Legend~ see Fig. 3 LOG OF TEST BOR I NG 7
CARLSBAD LAKE CO~MUNITY
~I:X:)[:'4,·,'~RD -G! Z I ENSK I & ASSOCl'.lHES 1
1
'
COilSULTING SOIL AXD FCUriDATlC;t D:GINEEi\S A)lD GEOLO~IS:rS
SA.1j 0 lEG:). Cl.LI FO,~:l1 A
D":::_!lY: GLI,,J PDP()~:,.l~.E.:..._~.:"':L-,! "':':":':L~.z.::.::.:~~? __ ) j"""-~-~''':~~~~-'M __ .. __________ .. ~.~:,~,57..; ,,:.~=J D:.,~~.;.~.,~.Zj L~ L?,1,~,v~~"A'" L ~ ',-I" '::~., ~\I2~ .. ,~ Z"'''o-::: . .H
•
• ~ ~ ~ ~ ~ ~ ~ " j
~ ~ •
n
H ~ ~ +' ~ (!)
s (!)
lL.
~ I • ~ (!)
§ u ro ~ '+-L
::J
g U)
-0 ~ C
::J ~ 0
~ L . , <D n
•
H :;::
~ 0 a ...-
1\ (!) lJ co II fi ..c:
I +' Co
(!)
0
1 ,1
•
l! g
:J
~l •• ~ ij
i ~ ~ •
! , •
• I
• J~
o -
5-
10 -
15 -
18 -
0-
5 -
10 -
15 -
Bor i ng 8
WC = =;-I
DD = 108 t--BC = 9
.. '.
Loose, damp, dark brown si lty sand .(SM)
-
BC = 2¥' . tlredium dense, damp, red-brown clayey
...... ':, sand (SC)
BC =
.' ':':':.,:
,:.::::::
:,-"; ,'.
,;.-.... ....
-.:-::::' " '.: , ... : ....
Bor i ng 9
we = In I I";' Loose, rno i st, dark brown silty sand
DD = 120 r' ('1'1) BC = 5 '.:...,' .~-----------------------------
. · .. ::ri.edium dense, damp to moist, yellow-
:J1...J":: brown to red-brcmn cl ayey sand (SC) Be = 221," .
BC =
" ,,::-'
2~1_'-f---_----'--r Dense, damp, gray-brcwn si lty sand
(~H)
BC= ~~~J-__________________________ __
LOGS OF TEST BORIHGS 8 & 9 '/
CARLSBAD LAKE C a,fl,WNI TY ~--------------------------------------------.! W)JL'WARD - G I Z I ENSK I & ASSOCI ATES i
CO)(SULTII<G SOIL AXD FOU;W.HlClI 8lGlliEERS "HD GEOLOGISTS I
SAJl 0 I ECD. CAll FOR1i I A I ~--------~--~~--~--------r----------~--p~. BY: GS J._~:..~0\LE: In = S' uE:~:l.~:.?2L"""'!1
CX'O BY: i;-; ..... ?fOATE: 7/19/71. FIP'~F iiI)· '3 t .--.,~ ____ ~.c.::_n. ... _~ •• ...:.~~~ .. ..,... .. , ........ __ ... )!;; _ .~:... ..... 6'. '-",,;: ~L"':;-,.~·,Il""~:'~ •• J
I
f I
•
•
•
•
•
•
•
•
•
•
•
3: o
..c::
+' c:..
C) c
o -
5-
10 -
15 -
18 -
0-
5 -
10 -
15 -
Bar i ng 8
we = f,
DO = 108 r--,:', Be = 9
Loose, damp, dark brown si lty sand ,(SM)
-
,.=.:.'':'
.'-;'-:':: , ,
:':" .. ::::'::
Bori ng 9
damp, red-brown clayey
we = 'n' I'" ,: Loose, mo i st 1 dark brown s i 1 ty sand
OD = J~2' "(<::'1) Be = 5 ':.' VI'
--~-----------------------------',:':.:i, tJ.edium dense, damp to moist, yellaw-
Be = 23 2 ,'," brown to red-brCfflTI cl ayey sand (SC)
. ',' . " .. :'
Be = 2~
Dense, damp, gray-br~~ silty sand
( ~H)
Be= ~~~ __________________________ __
LOGS OF TEST BORIHGS 8 &9
CARLSBAD LAKE C C·!:,iUH I TY
kCOL'WARb - G I Z I ENSKI & ASSDC I ATES • . '/
COXSULTII(G SOIL AXD FOU;iD.l.TIC;1 EHGlIiEE!\$ AHD GEOLOGISTS "
SA}j DIEeD. CALlFOR:iIA ,I
! 1 I
•
.'
•
•
•
•
•
•
•
•
I
I.
..c
+-' D-
O)
C
0-
.5-
10-
15-
0-·
5-
10 -
13-.
.. . . ." ... :; ,.,~. -. ,:-,-... '"; ......
Boring 10
-WC = lj. 1 DD = 106 f---:--BC = 16
~led i urn dense, damp, .1 i ght .br:~n silty
.' fi ne sand (SM)
-..... I-----~----------
BC = 28~ .: ..... ~ l'I.edium dense, to very dense, damp, J-i -red-brown clayey sand (SC)
,: .:: ....
BC =
~;.~----------~-~-----..... : .... ,:' ' .. :: .. ' Dense, damp, gray-brown si 1 ty sand
• ..., lj.; ... .'<~:. (SN) BC= 37~~"'~<~~ ________________ _
Bor i ng II
." "',: Loose, damp, 1 ight brOiffi si 1 ty sand
" (SM)
---~------~--------------.:' .. :; Medi urn dense, damp, yellow-brown to
.. :'. red-bra-..n clayey sand (SC)
Dense, damp, red-brOtJn silty sand (&vI)
For Legend, see Fig, 3 LOGS OF TEST BORINGS 10 & II
CARLSBAD LAKE CO~MU~ITY
1,..coC',·JARD -GIZIENSKI & ASSOCIATES ,,:/
COUSULTIIrG SOIL J...~D rOUiiC.HlC:~ 8lGlti::E~S AHD G[CL03ISTS 'i
SA!l DIEm, CALlFO:::HA !I
~R, BY: Gs __ J ArDOn'!:, SCAIJ: I" = 5' ! 1>01)..'1.":";. 73:]21-.1/ ------.~ ....... .......",....4=_ _____ S~~~;,,-,.~d .. 2_~!.~:.!. ....... ..zlt9J1.L__.~I~L~· ·:~ .. :~.i:r.~~r?'~~A<~' U
•
•
•
•
•
•
•
•
•
•
•
I I ~ 1 ~ ~ ~~ ." ~ n ~ .
~ ~
H a
a ~ ~ ]
!l ~ ~
:J ~ ~ ,1
1 ~ ~ ~ ~ ~ ~ j
~ ~ ~ ~ ~
! I ~ ~ ~
::;: o
(j) co
0-
5-
10 -
13 -
0-
5 -
10 -
15 -
. ,. . .... -.. .
Bar i ng 12
Loose, damp, 1 ight brown silty
. .. sand (Sf·f.)
. ,..-"... "
---~----------------------------
H8dium dense, damp, brol-In to red-
.. brown clayey sand (SC)
--.:."
:-. ':.( :: . ~
-.,-:
...... :.
., Dense, damp, brov,'ll to yeJ low-brOtm
~t::;\;::: s i 1 ty sand (SM)
F';',::',
Bar i ng 13
we = II ~,~ Loose, damp, dark brOtin silty sand (S1~)
DD = 118 . '. 1\ 8C = 5 .1 \'--______________________ --,._
.'<'::' Medium dense, damp, red-brown clayey = \'Ie = II 2 DD = 119 f--BC = 25
-
Be = 27~
. :~. sand (SC)
_._+--------------------------
Very dense, damp, red-br~~n silty
sand (S~)
BC= 70~L-,~----------------------------
For Legend, see Fig. 3
'; .
::
i ~.coCW,QRD -GIZI8~SKI & ASSOCIATES il ~ CD:iSULTIIlG S.Oll !..XD rCU:WATlC?l OlGIHEEflS AllD G£OLOG.lSTS 1,'1
LDGS OF TEST BORINGS 12 & 13
CARLSBAD LAKE CO~MUNltY
~ SA)! DIEW. CALI ro;:'lI A
~ l'R. BY: GS' ~~!.~: I" ,; S:"'IJ ~"..:ll...!'f)j T~.:??L .. .J
J ___ -.......,... _____ =r::::_~""""=====~~:::.:.:~~~~.B~:::::~V-.:.:::~:'!::?'::!.==~:.::D~::=l:::~.~~:.~-:::7~/~::.=11::::;/,=~l::!!.-..-=::=~w .. ~::.:f.=-~.r_ol-=.,.,.r:..::!J=.:!:f.::;0,;,,=:-~ ... -,.-,:::::.I.~~ ••. :.!.:,..,.:3~:.:;.I.1
•
•
•
•
•
•
•
•
•
•
•
u
+' 0>
0> L1...
-0 C
::::J o I....
<.!J
3: o
0> a::\
..c: +'
C>-
O>
Cl
0-
5-
10-
l.5 -
18 -
Cut Slope 14-
Loose to rr:edium dense, dry, red-bro.·r.1
si lty sand (St,1) 51 ightly porous
.... Dense, darnp, red-brown c1 ayey sand
(SC)
e •.
! I I
f
I I
Ii
... ------------------------------------~.~. -----_.-
•
•
• I 1 1 ,1 II ,1
II
II
Cl :;z: -CI)
CI) II « C>..
•
I ~ :z: w
I <-> "'" !u I 0-J ! • I
I ! I i I •
I ,
•
•
•
•
•
SIlT and CLAY
GRAVeL SAUD COBBLES I---=:.:.:..:..=-=----lf__~_r_ I-.--:.~-r-----I
Ct.::'1rse Fine Co3rsd Hedium Fine
I
100 7 6
90 I I
~~sh O~nin~" ~-~i~n~s.~~----~S~i~ev~e~Si~z~e~s----_.----~H~yd~r~oo~~~t~er~M~a~l~y~si~s~_, ,-I I I
3 2 If .L 10 16 20 30 4-0 60 80 IlJ.O ?OO r--------r--.....,...---~ " ~'\ l.
\ .
80~:~---~~~-+4--+4--+4--~1--~~~\--+-.~~~-+-------+---+------~
\ ,,:
. \ \ '.
lJ.OHI~-44~+-4-+-~+-+-~-~-+-+-+-+r~\r'-~_+~--4-1 --+---+----~
I t, H-~-~~r-~--~~~----~_+_+_+-r-'r\ITi\-+~,~\'-r-+---/~ ---~
/ H-~--~~r_~--~-~----~_+_+_+_+-4.~.+-~~-.. ~.~~-,~~----3M 2
~~~-~~~~--~-~---4__+_+_+_+--*~I-+'~f--~~~~~'~·~------~--+-------~ H-~-,H_+__l-+_+-+_+-+_+---~_+,. '., --.......:----...L
3-6·~~~~~~~-~~·~·~~======~ ~. -----'-", -3-l~ -+1"---=-..1.=---=:::-"':-:--1 , --:
o
10
20
30
c u.J
lJ.O:: « I-LU
0::
~ &'Jz -w <-> c=: u.J
0-
60
70
80
so
~~~I-Jf~4-~+-~-H-~H----~-+~+-~+-~~~·~f--+-------T--_+--~~ a 100
100 50 10.0 5.0 1.0 0.1 0.05 0.01 0.005 0.001
GRAIN SIZE IH MllL!~IETERS
SA;I.PLE CLASSIFICi\TI~~ AND S,{}::BOL *LL *PI
~~3--~2--~~Cl~a~ye~~(~.t~~)------------------+_------+_--~-~~
3 -lj. S i 1 tv sand (S)·O
3 - 6 Silty sand (S,~)
lj. -I Clayey sand (SC)
* LL = L i qui d Lim i t
*PI = Plasticity Index
GRAIN SIZE DISTRIBUTION CURVES
CARLSBAD lAKE COMMUNITY
.' :
!
I I' I
I
I I I
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•
•
•
•
•
•
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; -. -, ,---:~:~. ~ . ,,~~.~~;: !,~ .. __ -=-~~.~~~~~:~~~~ __ ~'.~ ~~.: ~~~.=~~.~ .. ~ :~·~=~~r·7-' --~::.~~.~
: _ I .' , } r . . . [~',. I.....:· .: . i •. ..
.... --~ J
I
Sa.;;p 1 e
iJurr.)er
7 - 6
13 - 2
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""--------
RESULTS OF CONFINED CrudPRESSIOW TESTS
Initial Final
Dry \v'~ter Dry Water
Density ContentSai:uration Density C.ontent 3aturation, Pressure Co.7i-?reSS ion
pcf -
110
112
% aI 10 pcf
T
---
12 60 116
II 65 117
500
.. % %
15 .90
IIJ. 90
PRESSURE -psf
750
psf
1000
1000
1000
~ Sampl, ~:_:~""l Mol,t"e Coote, V
'7..}-=::--h )
% of Initial Hei grrt -
1t.8 I
3.3
IJ. ~--~----4-----~---+----~----~---+----~--__ .~---+----~
6 ~---+----~----~---+----~----~ __ -+ ____ ~ ____ ~ __ -+ ____ ~
RESULTS OF COIIF IIIED C011PRESS I 011 TESTS
CARLSBAD LAK E CCf.lI·lUN ITY
~----~----------------------------~' ("''COD,!£\RD - G I Z I EN SK I. & ASSO C I A TES
COHSULHIoiG SOIL MID FG[;~iDhTlO~ ENGIN~ERS AND GEOLOGISTS
S~" DIEGO. CALIFO~NI4
OR. BY: GS 1 ~?p:;>ox. 5C'\Lt: - - - -PDOJ. !-{o: 73-2.3.U1
('I('D !W: >'/-,..-z.. i O.\,TE: 7/23/73 ] fJ\IJl<E I-iO: 13 . ij
I I I I
I
II
. "' 'lIN • •
DIRECT SHE.t,R TEST DATA 2
Dry Density. pcf 118 II
• Initial Water Content. "/. 9 8
Final riater Content. % 13 15
Apparent Cohesion. psf 600 360
Apparent Friction Angle. 0 26 18
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3
100
80
CI) ~ 60
0...
I-ffilJO c..:> cr: w no
" MECHJ,,'iICAL t.NALYSI S . :: ..
3 4 ~ 10 lI0 200
I~" \~ !\
1\ \ \\-<:.. f-2
j;1
1-r+\\
I ~;..
~~--'
I I "'"-=
20
I o 1000
I I
PLASTIClll' C-HARACTERISTICS
Liq\Jid Limit. %
I I I I
2 3
22
Plasticity Index. % 7 --~--------+-----~~-+----~
Classification by Unified Soil
Classification System
SV,ELL TEST DATA
SM sc
? v
Initial Dry Density. pcf I:T---~~------+-~~~~-r----~
Initial Water Content. % --~~~----+-----~---+----4
Load. psf
Percen t S~..e I I
SPECIFIC GRAVITY
Specimen I = I - 3
Specimen 2 = 3 - 3
Specimen 3 =
L 1/ I
I I II II I I
I
I I I ,I
I I
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Assumptions:
..... , -~ ,.,.... . . -........ -.~ ....... ,
SLOPE STABILITY
CUT SLOPE "
(1) Maximum height of slopes,
(2) Maximum"slope inclination,
(3) Unit weight of soil,
(4) Apparent angle" of interna] friction,
(5) Apparent cohesion,
(6) No seepage forces.
References: .
H = 40 2 • 1 "D "";'; • 26~ • , f.)
y. = 130
~ = 35().
C = 200
(1) Janbu, N., flStability Analysis of Slopes with Dimensionless
Parameters l', Harvard Soil Mech~nics Series No. 46, 1954.
(2) Janbu, N., IIDim~nsionless Parameters for Homogeneous Earth
S.l opes II, JSt·1FD, No. Si~6, November, 1967.
Analysis: "
Safety Factor, F.S.
)' H tan <t>
c =
Where Ncf is the stability No.
for slopes with both c and ¢.
130x40x.700 = 18.21 200
From Fi gure 10 0+ Reference 2
51x200 F • S. = 130x40 = 1. 96
N = 51 cf
O.K. FOR SEISMIC
" WOO D \It A RD· G I Z I £ N SKI &. AS S 0 CI ~ IE S
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APPENDIX B
t?LOPE STABILITY
CUT SLOPE
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 = 15'
2 to 1
y = 125 pef
cj> = 30°
c = 300 psf
(1) Janbu, N., "Stability Analysis of Slopes with
Dimensionless Parameters,1I Harvard Soil Mechanics
Series No. 46, 1954.
(2) Janbu, N., IIDimensionless Parameters for Homogeneous
Earth Slopes,1I JSMFD, No. SM6, November 1967.
AniJ.lyses:
SiJ.fety Factor, F.S. = c
yH Where Ncf is the stability
number for slopes with
both c and <p.
). cf = XI:! tan 1 = 3.6 c
From Fig. 10 of Reference ( 2) N = 16 cf·
)' F.S. = 2.5
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APPENDIX B
SLOPE STABILITY
FILL SLOPE
Assumptions:
(1) Maximum height of slopes
(2) Maximum slope inclination
(3) Unit weight of soil
H = 25'
2 to 1
(4) Apparent angle of internal friction
(5) Apparent cohesion
y = 120 pef
<p = 25°
c = 250 psf
(6) No seepage forces.
References: .
(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. =
Acf = XII tan 1 = 5.6 c
From Fig. 10 of Reference
F. s. = 1. 75
c
yH
( 2) N 8f' '-
Where Ncf is the stability
number for slopes with
both c and ¢.
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APPENDIX B
SLOPE STABILITY
FILL SLOPE
Assumptions:
( 1) Maximum height of slopes H = 15'
( 2 ) Maximum slope inclination 1-1/2 to 1
( 3) Unit weight of soil y = 120 pef
( 4 ) Apparent angle of internal friction cf> = 25°
( 5) Apparent cohesion d 250 psf
( 6) No seepage forces.
References: .
(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, Nove)11ber 1967.
Analyses:
Safety Factor, F.S.
. 1. cf = yll tan 1
c
=
= 3.4
c
yH Where Ncf is the stability
number for slopes with
both c and 4> •
From Fig. 10 of Reference (2) Ncf '= 14
P.S. = 1.9
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APPENDIX B
SLOPE STABILITY
SURFICIAL SLOUGHING
SEEPAGE PARALLEL TO SLOPE
------
-- - - --"---Failure Surface -
F .. S. = C I + ( if -~'" ) d COS2 i tan ¢ I
<I'd sin i cos i
j\SSUf.1PTIONS:
1) Depth to failure surface
2) Unit weight of soil
3) Unit weight of water
4) Slope inclination angle
5) Soil effective cohesion
6) Soil effective friction angle
P.S. Safety Pactor 1.84
d = 3'
5 = 120 pef
~III -= 62.4 pef
i = 33.7°
c'= 250 psf
¢'= 25°
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APPENDIX C. -
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-
ance with these specifications. A soil engineer shall be the
m-mer I s representative to inspect the construction of fills.
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
of grading. Deviations from these' specifications will be
permitted only upon written authorization from the soil
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.
II. SCOPE
The placement of controlled fill by the contractor shall
include all clearing and grubbing, removal of existing unsat-
isfactory material, preparation of the areas to be filled,
spreading and compaction of fill in the areas to be filled,
and all other work necessary to complete the grading of the
filled areas.
III. 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 sui "table 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 ma-terial of a
perishable, spongy, or otherwise improper nature shall be
used in filling.
2. Material placed within 24 inches of ro~gh"grade shall be
select material tha-t contains no rocks or hard lumps greater
than 6 inches in size and that swells less than 3% when
compacted as hereinafter specified for compacted fill and
soaked under an axial pressure of 160 psf.
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APPENDIX C
3 . Representative samples of material to be used for fill
shall be tested ~in the laboratory by the soil engineer in
order to determine the maximum density, optimum moisture
content, and classification of the soil. In addition, the
soil engineer shall determine the approximate bearing value
of a recompacted, saturated sample by direct shear tests or
other tests applicable to the particular soil.
4. During grading operations, soil types other than those
analyzed in the report of the soil investigation may be
encountered by the contractor. The soil engineer shall be
consulted to determine the suitability of these soils.
IV. COMPACTED FILLS
1. General
(a) 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.
(b) Potentially expansive soils may be used in fills below a
depth of 24 inches and shall be compacted at a moisture
content greater than the optimum moisture content for
the ma·terial.
2. Clearing and Preparing Areas to be Filled
(a) 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.
(b) 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
shall be removed or compacted ·to the depth shoW11 on the
plans. The surface shall then be plowed or scarified to
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.
(c) Where fills are constructed on hillsides or slopesJ the
slope of the original ground on which the fill is ,to be
placed shall be stepped or keyed by the contractor as
shown on the figure on Page 4 of these specifications.
The steps shall extend completely through the soil
mantle and into the underlying formational materials.
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APPENDIX 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
layers that, when compacted, shall not exceed 6 inches.
Each layer shall be spread evenly and shall be thorough-
ly mixed during the spreading to obtain uniformity of
material in each layer.
(b)
(c)
(d)
(e)
v.
When the moisture content of
that specified by the s,oil
added by the contractor until
specified.
the fill mat~rial is below
engineer, water shall be
the moisture content 1S as
When the moisture content of the fill material is above
that specified by the soil engineer, the fill material
shall be aerated by the contractor by blading, mixing I
or other satisfactory methods until the moisture content
is as specified.
After each layer has been .placed, mixed, and spread
evenly, it shall be thoroughly compacted by the contrac-
tor to the specified dens tty . Compaction shall be
accomplished by sheepsfoot rollers, vibratory rollers,
mul tiple-wheel pneumatic-tired rollers, or other types
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
sufficient trips to insure that the desired density has
been obtained throughout the entire fill.
The surface of fill slopes shall be compacted and there
shall be no excess loose soil on the slopes.
INSPECTION
1. Observation and compaction tests shall be made by the
soil engineer during the filling and compacting operations so
thut he can state his opinion that the fill was constructed
in uccordance with the specifications.
2. The soil engineer shall make field density tests in
uccordance with AS'l'M Test No. D 155664. Density tests shall
be made in 'the compacted materials below the surface where
the surface is disturbed. When these tests indicate that the
density of any layer of fill or portion thereof is below the
.specified density, the particular layer or portion shall be
reworked until the specified density has been obtained.
0(".
• .. APPENDIX 'C
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VI. PROTECTION OF WORK
1. During construction the contractor $hall properly grade
all excavated surfaces to provide positive drainage and
prevent ponding of water. He shall control surface water to
avoid damage to adjoining properties or to finished work on
the site. The contractor shall take remedial measures to
prevent erosion of freshly graded a~eas and until such time
as permanent drainage and erosion control features have been installed.
2. After comI21etion of grading and when the soil engineer
has finished hls observation of the vlOrk, no further excava-
tion or filling shall be done except under the observation of
the soil engineer.
Strip as specified
0:r:iginal ground
'Slope ratio = N
.M
Fill
R:.:ro~le all to~)<"o J'l / .. ' .... ~;: ...... > >.:;: .. ,.0 .. -J ~
J~ 13 }-/.~;. -,.t
VaJ;'ics J..<-'" :~ See
Sec nOlci
NOTES:
The minimum Hidth "B II of key shall be 2 feet wider than the
compaction equipment, and not less than 10 feet.
The outside edge of bottom key shall be belm., 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 .
note