HomeMy WebLinkAboutCT 73-39; Spinnaker Hills; Preliminary Soils Report; 1973-09-25PREPARED FOR:
Staixiarci Facific Corporation
7570 Clairemonl: Mesa Boulevard
San Diego, California 32111
PREPARED BY:
Soui.hern California Testing Labora.tory, Inc. 6280 Rivcrda1.e Street
San Diego, Cslifornia 92120
Post Dfiice Eox 20627
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Standard Pacific Corporation
San Diego, California 92111
7670 Clairemont Mesa Boulevard SCT 312503
Report No. 1
Attention: Mr. Bob Allen
SUBJECT: Preliminary Soil Investigation for the Proposed 80 Acre
Sea Ranch Residential Site, Lagoon Lane, Carlsbad,
California.
- Ger?tlemen:
In accordance with your request, we have performed an^ investigation of the soil conditions at the subject site. We are transmitting
herewith a report of this investigation.
The analysis of our findings is intended to provide the required information to design the foundation and grading plans for the
proposed development.
The major adverse soil conditions are as follows: loose, highly compressible, silty sands (alluvial deposits Qal-cl geologic classi-
also west of Boring No. 5 in the vicinity of the existing earth dam; fication), which are located along the western edge of the site and
and potentially highly expansive, intcrbedded, slightly clayey silt layers (of the Es geologic classification), which were encountered
in the eastern portion of the site above the approximate elevation of 245 msl.
Recommendations are contained in the body of this report for the disposal of the above-mentioned potentially detrimental soils.
SCT 312503 September 25, 1973 Page Two
~f you have any questions after reviewing our report, please do not
hesitate to contact this office.
This opportunity to be of service is sincerely appreciated.
Respectfully submitted,
SOUTHERN CALIFORNIA TESTING LAB., INC.
R. Douglas Hamilton, R. C. E. .(A”
RDH:bjl
cc: (12)
( 1)
( 1)
Geologist -
Submitted
R. M. Galloway & Assoc.
SCTL, Escondido
Attn: Jerry Bryant
$q;CTION
1
2
2.1
2.2
2.3
3
3.1
3.11
3.12
3.13
3.2
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~ 3.3
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4
~ 4.1
4.2
4.3
4.4
5
6
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TABLE 0 F CONTENTS
- ITEM PAGE NO. ”
Project Description and Scope . . . . . . . . . . . 1
Findings. . . . . . . . . . . . . . . . . . . . . . 2
Site Description. . . . . . . . . . . . . . . . . 2
General Soils Description . . . . . .. . . . . . . 3
Geology. . . . . . . . . . . . . . . . . . . . . 4
Recommendations . . . . . . . . . . . . . . . . , . 4
Foundations . . . . . . . . . . . . . . . . . . . 4
General . . . . . . . . . . . . . . . . . . . . 4
Expansive Characteristics . . . . . . . . . . . 5
1
Settlement Characteristics. . . . . . . . . . . 5
Slope Stability . . . . . . . . . . . . . . . . . 6
Earth Retaining Structures. . . . . . . . . . . . 7
Earthwork.... ................. 7
General . . . . . . . . . . . . . . . . . . . . . 7
Trnasition Lots . . . . . . . . . . . . . . . . . 7
Disposal of Nonselect Soils . . . . . . . . . . . 7
Compressible Soils. . . . . . . . . . . . . . . . 8
Field Explorations. . . . . . . . . . . . . . . I 8
Laboratory Testing. . . . . . . . . . . . . . . , 9
PLATE NOS,.
Plot Plan, Boring Logs, Trench Logs, Test Results. . . . . . . . . . . . . . . . . . 1 - 19
Recommended Grading Specifications, Special Provisions, Unified Soils Classification System. . . . . . . . . . . . . . . . . . . Appendices
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INSPECTION TESTING RESEARCH DEVELOPMENT
6280 Riverdale St. San Diego. California 92120 Phone 280-4321
REPORT OF PRELIMINARY SOIL 1NVESTI.GATION
PROPOSED 80 ACRE SEA RANCH RESIDENTIAL SITE
LAGOON LANE
CAFUSBAD, CALIFORNIA
1. PROJECT DESCRIPTION AND SCOPE
~ This report presents the results of our soil investigation for the
proposed residential development to be located southeast of the inter-
~ section of Poinsettia Lane and Lagoon Lane and approximately one-
i Aour-th mile north of Batiquitos Lagoon (see Plate No. 1). A brief
~ legal description of the site is the north 1/2 of the southeast 1/4
i of Section 28, T.12 S., R,.4 W. ,' S.B.B.M., City of Carlsbad, County of
~ San Diego, State of California. Tt is our understanding that one and/
~ or two story woodframe residential structures with slab-on-grade con-
j struction are planned for the site.
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~ It is further understood that maximum cuts and fills in the order
~ of 50 feet are anticipated. The site configuration, test boring. i
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and test trench locations are shown on Plate No. 2 of this report.
This soil investigation was undertaken to:
a) Determine the physical properties of the prevailing soils
including their supporting capacities and settlement charac- 1.- . teristics.
b) Provide design information regarding site preparation and
foundations.
SCT 312503 September 25, 1973
1
Page Two
2. FINDINGS -
! 2.1 Site Description
I The rectangular-shaped site ranges in elevation from 50 feet above
!,lean Sea Level in the southwest corner to approximately 300 feet in
tha southeast corner. Natural drainage is primarily westerly on mostly
gradual slopes, although steeper slopes of as much as 3:l are located
on the western side of the promontory situated near the site's eastern
boundary, A major ravine traverses the site from the northeast corner
to the the west, across which an earthfill dam has been constructed
i at approximate midpoint downstream. Adjacent to the drainage courses,
"tadland" type topography with near vertical slopes has resulted
from differential erosion of sandy soils. These features are most - terisive towards the westerly and southeasterly portion of the site
where deeper ravines have developed.
Vegetation consists of small stands of eucalyptus trees across the
western side of the site, with more extensive stands on the eastern
side, and scattered trees located along the ravines and behind the
earthfill dam. Various types of brush and shrubs line ravine bottoms
and other areas. The area bounded by Boring Nos. 5, 6, 8 and 11 have
been cleared for agriculture planting.
Prash, consisting of dumped car bodies, paper, plastic and metal containers,
litiers the site in canyon bottoms and other locations.
None of the subsurface explorations encountered ground water and
*?re was no further evidence of buildings or other manmade structures.
September 25, 1973 Pi
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?.2 General Soils Description
::. general, the majority of the site consists of dense silty sands
::ld clayey sands which are competent foundation materials for the
.:-oposed construction. A 4 to 5 foot layer of highly expansive clayey
:ilts (ESlt) was encountered at a depth of 8.5 feet: j.n Rorina N~. 7.
:C appears to be continuous throughout the 245 to 250 foot elevation.
.urficial exposures i.ndicate the presence of another layer of clayey
silt between the 280 to 290 foot contours. Because these materials
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:.;~ve high expansive potential and low shear strength characteristics,
.:;jccial measures with respect to selective grading (see Expansive
:i,aracteristics) and slope stability (see Slope Stability) may be
~ccessary.
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:icep compressible deposits Of alluvium (Qal) were in ~~~j~,,~
:.v. 1. The approximate lateral extent is shown on Plate No. 2, however,
:he depth to dense competent formational soil was not determined.
consolidation tests indicate that at least the upper 6 feet of alluvium
vi11 require recompaction prior to receiving additional fill and/or
structural loads. The actual depth and extent of recompadtion necessary
:,ay either be determined during grading or by an additional investigation
of this particular area.
-
The only other soil condition encountered which will require special
attentiun.is the small dam an& pond area underlying Lots 278 to 286.
, In this area, all man made fills and alluvial soils should be removed
to firm, natural ground and recompacted.
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i SCT 312503 September 25, 1973 Page Four
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2.3 Geology
! ' The entire site consists of sedimentary materials. A brief description ' of t.he geologic soil-rock units is presented on Plate No. 2 and a
\ geologic cross-section is shown on Plate No. 3. Bedding attitudes
taken in gulleys at the east end of the site were N40W5SW and N60W4SW;
1 essentially flat lying materials. AS a result, we Mould not anticipate
sl.ope stability problems to be aggrevated by adversely dipping beds.
~ Faulting was not observed in any of the gulley exposures or in subsurface
borings. A fault trace was suspected traversing the site in a north-south -
,' direction at approximate elevation 225. Ilowever, trenching of the
i area revealed the apparent faulting as an abutment unconformity between
! EGcfnc
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.- (Eslt-Ess) znd Quaternary (Qt2) materials, (i.c. ax? irregalarity
due to deposition of younger terrace sands over the older sands).
Landsliding was not directly observed on the site but is suspected.
ilnmediately adjacent to the easterly boundary. According to the
tentative grading plan, dated August 2, 1973, site girading above the
slide area will daylight in natural ground undisturbed by londsliding.
It. is our opinion that site grading will not adversely affect this
area. The removal of the elevation 300 hilltop should have a stabil-
j izing effect with regard to future sliding. 1 i - 3. RECOMMENDATIONS
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~ 3.1 Foundations I ' 3.11 General: Conventional spread footings founded in nonexpansive
- soil are recommended for the support of the proposed structure. Con- L
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I scr 312503 September 25, 1973 Page Five 1-
1 veritional spread footings should be founded a minimum of 12 inches
~
~ below the adjacent fi.nish grade, have a minimum width of 12 inches
~ aril may be desi.gned for an allowable soil hearing pressure of 2.0
j kips per square foot. The above allowable stresses may be increased
, by one-third for wind and/or seismic loading and should be decreased
~ by one-fourth for dead load only.
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~ Adjacent footings founded at different bearing levels should be so i located that the slope from bearing level to bearing level is flatter
' than one horizontal to one vertical. !
I 3.12 Expansive Charact:eristics: "" The expansive characteristics of
t.hc clayey sj.lty soils described previously will require special ! I .-
Jnsideration and/or design so that structural damage is not likely
to occur.
~
~ It is recommended that wherever expansive soils are used in fill, 1 it be placed a minimum of 2.5 feet belaw finish grade and wherever i it. occurs within 2.5 feet of finish grade, it be removed and replaced
~ with nonexpansive soils. Conventional footings may then be umed
1 for the proposed structure. i ;
The limits of the above recommendation shall apply to the area within
a perimeter of 5 feet outside of the proposed structujte.
3.13 Settlement Characteristics: Anticipated total and/or differential
settlement may be considered negligible ljrovided the following recommen-
-. L ations are used: The man made fills and compressible alluvium in the
3CT 312503 September 25, 1973
.-
',rea of the old reservoir and along Lagoon Lane are to be remCvC.
firm ground and recompacted in accordance with the attached Recox:::
Icd Grading Specifications and Special. Provisions.
3.2 Slope Stabili-ty "
;'he fill slopes as proposed on the grading plan presented by R. M.
,^allormy and Associates, Inc., dated August 2, 1973, were found to
be stable in relation to deep-seated failures.
The stability of cut slopes located in the eastern portion of the
site (i..e.) on higher elevations, will be depepdent on the size and
location of the weaker silt stratas wit.hin this formation. Based
: on strength parameters of these weaker soils, it is our opinion that
-, cut slopes within this unit wiil be stable with relati011 to deep-
seated failures if constructed at or flatter than the following recornell--
, ded slope ratios expressed in horizontal to vertical units for the
indicated heights :
j Cut Slopes to 30 Feet in Height: /' 1.5:l.O
to 60 Feet i.n Height: . 2.0:l.O
~ Cut slopes, in other areas of the site where the above-mentioned soil
i conditions are not encountered, will-be stable if constructed at or
I i flatter than 1.5:l for a maximum of 45 feet in height.
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I The above mentioned maximum heights were determined using a factor
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~ of safety of 1.5 and not considering seismic loading.
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~ sc'r 312503 September 25, 1573 Page Seven
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3.3 Earth Retaining Structures
!
!Active and passive soil pressures for the design of earth retaining
m structures will be dependent upon the particular soil conditions being
,considered. Should this information be necessary for design purposes,
i please provide this office with the location and type of wall proposed.
4. EARTHWORK -
1 4.1 General
~ Earthwork and grading contemplated for site preparation should be
!
accomplished in accordance with the attached Recommended Grading
~ Specifications and Special Provisions. Structural backfill should
be compacted to a minimum relative compaction of 90 percent as determined
/"
-.!)jr A.S.T.M. 1557-66T, Metho? A.
4.2 Transition Lots
_I
Foundations supported partially on cut and partially on fill are not
recommended. The tendency of cut and fill lots to compress differentially
will probably cause unequal support and consequential cracking of
foundations and floor slabs. Therefore, in transition areas, we recommend
that the entire area be undercut 1 foot below the base of proposed
footings and be replaced with soil compacted to minimum density mentioned i
I in Section 4.1. i I I 4.3 Disposal of Nonselect Soils I
~ ME recommend that all detrimentally expansive soils or soils with
j low strength parameters be placed in fill slopes at locations such
as that designated as "nonselect soi1.s" on the accompanying sheet
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! entitled "Special Grading Recommendations" (see Plate No. 20).
SCT 312503
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September 25, 1973 Page Eight
4.4 Compressible Soils
As previously recommended in Section 3.13, all loose, compressible
soils, such as those encountered in the vicinity of Boring No. 1,
should he removed down to fi.rm, natural ground and recompacted to
a minimum of 90 percent of maximum dry density as determined by A.S.T.M.
1557-70.
5. FIELD EXPLORATIONS
Eighteen subsurface explorations were made at the locations indicated
on the attached Plate No. 2 on August 29, 30, and Sept-ember 7, 1973.
These explorations consisted of eleven borings drilled by means of a
rotary auger drill rig and seven trenches dug by means of a backhoe.
- 'The expl.orations were conducted under the observation of our enginocriag
geology personnel.
The explorations were carefully logged when made. These logs are
presented on the following Plate Nos. 4 through 15. The soils are
described in accordance with the Unified Soils Classification System
CIS illustrated on the attached simplified chart, In addition, a verbal
textural description, the wet color, the apparent moisture, and the
density or consistency are given on the logs. Soil densities for
granular soils are given as either very loose, loose, medium dense,
dense or very dense. The consistency of silts or clays are given
as either very soft, soft, medium stiff, stiff, very stiff or hard.
i ' SCT 312503
J.
September 25, 1973 Page Nine
Representative core samples were obtained by means of a split tube
sampler driven into the soil by means of the "kelly bar" of the drill
rig. The energy required to drive the split tube sampler is indicated j
I on the boring logs as the "penetration resistance". The core samples
I were carefully removed, sealed, and returned to the laboratory for
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I ~ testing.
I I Disturbed samples of typical and representative soils were also obtained 1 and returned to the laboratory for testing.
6. LABORATORY TESTING __ -
i I Laboratory tests were performed in accordance with generally accepted
1 I American Society for Testing and Materials (A.S.T.M.) test methods 1 are presented on the boring logs.
I
or suggested procedures. Representative samples were tested for their
natural densities and moisture contents. The results of.these tests
The expansive potential of clayey soils was determined in accordance
with the following test procedure and the results of these tests appear
on Plate No. 16.
Allow the trimmed, undisturbed sample to air dry to a constant moisture content at a temperature of 100" E'. Place the dried sample in the consolidometer and allow to compress under a load
of 150 psf. Allow moisture to contact the sample and measure its expansion from an air dried to saturated condition.
I In addition, the gradations, maximum densities, and the angles of
internal friction and cohesion were determined for typical and represen-
tative samples. The results of the tests are presented on Plate Nos.
16 and 17 of this report.
1 SCT 312503
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September 25, 1973 Page Ten
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/Two consolidation tests were performed and the results of these tests
are presented in the form of curves on Plate Nos. 18 and 19.
SOUTHERN CALIFORNIA proposed EO Acre Sea Ranch Residential
-
TESTING LABORATORY, INC. Site
SAN DIEGO. CALIFORNIA 92120
6280 RIVEFiDA1.E STREET Lagoon Lane Carlsbad, California
Existing Elev. 70
Finish Grade 123. (J i I
BORIMG NUMEER 2
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E -
32
19
99.2 3.1
102.3 3.7
Existing Elev. 97
Finish Grade 106
0 .:
. :: .. .;. :: . S1-i Orange, ury, ~cnse, SIL'yY Sj\l>lu - "- .. " . , ., "A
(Brown)
(Whj t.e , Humid)
"_I "- .
&& 57 117.3 8.1
LEGEND : : Sample Location 1
E: Sampler Penetration Resistance (Ft. Kips/Ft. )
Y: Natural Dry Density (pcf) I
M: Natural b!oisture Content (R of Y) i
SOUTHERN CALIFORNIA Proposed 80 Acre Sea Ranch Residc:ntial. I
"I 5kJ - TESTING 6280 RIVERDALE LABORATORY, STREET INC. Lagoon Lane
Site
SAN DIEGO, CALIFORNIA 92120 Carlsbad, California
-
BORING LOGS I ay I) r3 DATE
JOB &O,
8/30/73 ""_ PLATE TIC. 4 312503
." -7
-I.- 1
~y Elev.
Grade
Y -
119.2
115.2
120.8
155
143 M -
9.5
6.9
10.7
FOR LEGEND SEE PLATE NO. 4 i 9, SOUTHERN CALIFORNIA Proposed 80 Acre Sea Ranch Residenti‘a!
Lagoon Lane
Carlsbad, California
I
t;$ TESTING LABORATORY, INC. Site ,+.. ;-*e+ - 6280 RIVERDALE STREET
SAN DIEGO. CALiFORNlA 92120
”
BORING LOG BY
JOB NO.
DH
312503 PLATE NO. 5 .!
DATE
”. 8/30/73
“A
S3OP.ING NUMBER 4 - Exis Ling Elev.
Fini.sh Grade DESCRIPTION
1
"_
- E
3rown, Dry, Loose, SILTY SAND -
(Moist and Denser) .-
;ray' (Mottl~ed), Moist, Dense,
SLAYEY SAND
Qtz I
34
Drange, Moi.st, Dense, SILTY CLAYEY
SAND
70
,..
Light Grey, Moist, Dense, SILTY 100 _I_
SAND
'.
FOR LEGEND SEE PLATE NO. 4
Y -
113.2
126.2
117.2
116 I 6
185
130
P1 -
10.6
7.2
6.1
1.0 * 0
A TESTING LABORATORY, INC. Site
SOUTHERN CALIFORNIA roposed SO Acre Sea Ranch Residenti::l
-
SAN DIEGO. CALIFORNIA 92120 arlsbad, California 6280 RIVERDALE STREET cgoon Lane
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DATE-
BORING LOG DII 8/30/73 "_ .. ."
31.2503 PLATE NO. 6
""
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BORING NUMBER 5 Existing Elecr. 196
Finish Grade 218 DFSCRIPTION E
Grey-Brown, Dry, Loose, SILTY SAND -
Qal-cl ” I
(Medium Dense)
CLAYEY SAND
Yellowish-Brown, Humid, Dense,
Orangish-Yellow, Moist, Dense,
SILTY CLAYEY SAND Qt.
66
FOR LEGEND SEE PLATE NO. 4
r
Y M - -
102.9 2.0
SOUTHERN CALIFORNIA
TESTING LABORATORY, INC.
Proposed 80 Acre Sea Ranch Residential
Site
, 8280 RIVERDALE STREET Lagoon Lane
SAN DIEGO, CALIFORNIA 92120 Carlsbad, California
BY
JOB NO.
DH DATE
BORING LOG 8/30/73
312503 PLATE NG. 7
BORING PIUMBER 6 Existing Elev. 225
Finish Grade 218
DESCRTPTION E
Brown, Dry, Dense, SILTY SAND -
- (Topsoil
(Orange, Ilumid) Qt, --
"""
- - I ..
(Yellow)
Light Gray, Humid, Very Dense, Fine -1
SILTY SAND 80
-
"
." €3 __
I
Mottled, Moist, Dense, SILTY SAND
(Interhedded Hard Silt Layers)
Eslt
"
"_ - -
Orangish-Yellov, Moist, Very Dense, SILTY SAiJD with 1nterbedde.d Siits.
-__ E s3" - I "- "-I
(Grayish)
(Yellow-Orange)
84
.,
FOR LEGEND SEE PLATE NO. 4
Y M - -
121.9 7.7
118.3 11.2
SOUTHERN CALIFORNIA Proposed 80 Acre Sea Ranch Residential
TESTING LABORATORY, INC. Site
6280 RIVERDALE STREET
SAN DIEGO, CALIFORNIA 92120
Lagoon Lane Carlsbad, California
BORING LOG BY DATE DII
JOB NO.
8/30/73
312503 PLATE NO. 8 .-
BORING NUMBEli 7 Existing Elev. 260
Finish Grade 246
- DESCRIPTION
Brown, DrynSlightly Clayey GRAVEL
Dark Brown, Moist, Stiff, IIiyhly
Plastic, CLAY (With Some Gravel)
Grown, CLAYEY SAND - " _" -
- 1
Olive-Gray, Moist, Hard, SILT "_ €SI t __ I -
(Light Green)
"-
"- "-
(Mottled)
Gray, Moist, Dense SILTY SAND
(Thin Interbeds of Silt)
(Light Brown)
(Very Dense, Slightly Cemented)
E -
50
50
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Y M - -
124.3 9.3
112.6 17.4
.
FOR LEGEND' .SEE PLATE NO. 4
SOUTHERN CALIFORNIA Proposed 80 Acre Sea Ranch Residential
TESTING LAEORATORY, INC.
6280 RIVERGALE STREET
SAN DIEGO. CALIFORNIA 02120
Site
Lagoon Lane
Carlsbad, California
- BY
JGB NO.
BORING LOG DH DATE 8/29/73
PLATE NO. 9 312503
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BORING NIJMBER a Existing Elev.
Finish Grade
Y -
"-
(Orange, Moist, Medium Dense)
Mottled Gray, Moist, Dense CLAYEY
"- "-
" 25 117.9
"""-
(Denser, Cleaner Sand)
9.
127.0
SILTY SAND
"""
12.5
10.1
FOR LEGEND SEE PLATE NO. 4 - i
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SOUTHERN CALIFORNIA
Site I TESTING LABORATORY, INC.
Proposed 80 Acre Sea Ranch Residentjhl I
6280 RIVERDALE STREET Lagoon Lane
SAN DIEGO, CALIFORNIA 82120 Carlsbad, California
BY
JOB NO. ""1 ""
DATE
BORING LOG DH a12917 3
312503 PLATE NO. 10
DESCRIPTION
Brown, DIT, Loose, SILTY SAiGD
(Orange, Humid) Qtz" __
(Gradational)
Orange, Moist, Slightly Clayey
SILTY SAND
Existing Elev. 153 Finish Grade 155
(Less Clay)
""
Yellow, Moist, STLTY SAND _.
(Denser) ""_ "
Ess -
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E Y M - - -
FOR LEGENU SEE PLhTU NO. 4
SOUTHERN CALIFORNIA Proposed 80 Acre Sea Ranch Kesident.fci' TESTING LABORATORY. INC. Site
6280 HIVERDALE STREET
SAN DIEGO. CALIFORNIA 92120
Lagoon Lane Carlsbad, California -
I " ""
29/73
BORING NUPlBCR 10 "-
DESCRIPTION
Orange, Dry, Dense, SILTY CLAYEY
SAND QJL "
(Humid )
Existing Elev. 134 i Finish Grade 122-116 !
(Moist)
(Moist, Wet)
Li.ght Gray, Moist, Dense SILTY SAND
E ss " - __
FOR LEGEND SEE PLATE NO. 4
.
- E Y M - -
SOUTHERN CALIFORNIA
Lagoon Lane
Proposed 80 Acre Sea Ranch Residentic1
TESTING LABORATORY, INC. Site
6280 RIVERDALE SlREET
SAN DIEGO, CALIFORNIA 92120 Carlsbact, California
BY
JOB NO.
D 14 DATE
BORIlJG LOG 8/29/73
312503 PLATE 110. 12 "_
Brown, Hoist, Medium Dense, SILTY
3LAYEY SA?!D (Topsoil) "- -
(Orange) ._ _. (32.
FOR LEGEND SEE PLATE l?O. 4
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SOUTHERN CALIFOKNIA
Lagoon Lane
Proposed 80 Acre Sea Ranch Residential
TESTING LABORATORY. INC. Site
6280 RIVERDALE STREET
SAN DIEGO, CALIFORNIA 92120 Carlsbad, California
" ~ -[a?- BORING LOG DEI -7;
JOB NO. 312503 PLATE NO.
TRENCH MUF!HCR 1
TRENCH NUMBER 2
- .
GM
Reddish-Brown, Humid, Dense, CLAYEY SC
Brown, Dry, Dense, SILTY GRAVEL
Dark Orange, Humid, Dense, SILTY SC/
SAND
SM CLAYEY SAND
., . . ..
',
..
8 ;. ; '.; '.." . ,: '.
.. .. .. . .. ..
FOR LEGEND SEE! PLATE NO. 4
c
SOUTHERN CALIFORNIA
TESTING LABORATGRY, INC.
Proposed 80 Acre Sea Ranch Residectic31 Site
SAN DIEGO, CALIFORNIA 92120 Carlsbad, California 6280 RIVERDALE STREET Lagoon Lane
BY
TRENCH LOGS
DATE DH
312503 PLATE PJO . 14 7OZITO.
9/7/73
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TRENCH NUMBER 3
Slightly SILTY CLAYEY SAND Reddish-Orange, Dry, Medium Dense,
(Humid, Dense)
(Moist, Very Dense)
(Slightly Cemented) (Gradational) """-
.. ..
. .''.:. SM (Gray, Moist, Dense, SILTY SAND .. .
TRENCH NUMBER 4
.: Light Yellow, Dry, Dense, Slightly SN '. I-..
3-
(Humid) .. ': 2-)':. Silty, Medium Grained SAND .. .'. .,
..
TRENCH NUMBERS 5, 6, Ei 7
0
Soils in these trenches were terraced materials (Qt2) at the surface changing to ESS materials with varying depth.
These shallow trenches were excavated to determine the boundary between geologic formations.
FOR LEGEND SEE PLATE NO. 4 -
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SOUTHERN CALIFORNIA Proposed 80 Acre Sea Ranch Resicientia
TESTING LABORATORY, INC. Site
6280 RIVERDALE STREET Lagoon Lar.e
SAN DIEGO, CALIFORNIA 82120 Carlsbad, California
BY
JOB NO. TRENCE LOGS GATE nH 9/1/73
312503 PLATE NO. 1.5
DIRECT SHEAR 7 EST RESULTS
-,
DESCRIPTION
B8 '3 5-6' Remolded to 90% 30 250
MAXIIV?UM DENSITY & OPTIPJUM MOISTURE CONTENT
A ST M METHOD
-
DESCRIPTION
EXPANSION TEST RESULTS
4 SOUTHERN CALIFORNIA TESTING
". ,. ,
'l..?? LADORATORY, INC. RDH DATE 9 /13 /73 1:
i '> ,. , -, ~~~I ~ ~
6280 RIVERDALE STREET SAN DIECO. CALIFORNIA 92120 714283.6134
.. :!
Ji
'OB ''O' 312503
,.
GRAIN SIZE ANALYSIS AND ATTEHEURG LIMITS
I I I I I
l%',
%''
99.6 #4
100.0
3, " .4
$8
46.6 96.8 45.2 54.7 $50
92.7 98.2 91.. 0 93.5 $30
99.8 99 .o 99.9 99.9 #I6
100.0 99.4 100.0 100.0
40.3 29 -3 91.. 6 15.7
"
- " - -__.
" -
- # 100
#zoo 12.7 88.2 19.9 30.1
._
- "
.05 mm
,005 mm
70.0
,001 mm
38.0
15.0
LIQUID LIMIT 61
38
23
-
PLASTIC LIMIT
PLASTICITY INDEX
I CLASSIFICATION
UNIFIED
SM/SC SM/SC MH SM/SC 1
LOAD klps/sq.ft.
5
0.1 0.5 1.0 5 10 50
LOAD kips/sq.ft.
'UIU
W D Q
(3
LT
// :e., S0LIII:ERN CALIFOR:!IA 1ESiI::S Proposed 80 Acre Sea Ranch Residential j
(, : :1 ',. LIICORllTO:fY, INC. - !. -*,,.)
p, \: 7'
\\ ,'
Site
' . I,. 6280 RIVCF!DP\LE STREET Lagoon Lane SAN il1EGO. Chl IFOiil4IA 512120
71rI.;'ii0-43?1 Carlsbad, California
" "- ! . ,
RDH DATE 9/25"" i
RECOMMENDED GRADING SPECTFICATIONS - GENERAL PROVISIONS
GENERAL INTENT
The intent of these specifications is to establish procedures for
clearing, compacting natural ground, preparing areas to be filled
and placing and compacting fill, soil to the lines and grades shown
on the accepted plans. The recommendations contained in the prelim-
inary soil investigation report and/or the attached Special Provi-
sions are a part of the Recommended Grading Specifi.cations and shall
supersede the provisions contained hereinafter i.n the case of conflict..
INSI?E:CTION AND ’J’CSTING
“ i
A qualified soil eng:’r,c:r shall be employed to inspect and test t.hs
” earthwork in accordance with these specificati.ons. It will be neces-
sary t.hat the soil engineer or his representative provide adequate
inspection so that he may certify tha.t: the work was or was not accom-
pl.ished as specified. It shall be the responsibility of the contractor
to assist the soil engineer and to keep hiln appraised of work schedules,
changes and new information and data so that he nay make these certi-
fications.
If, in the opinion of the soil engineer, substandard conditions .are
encounteted, such as questionable soil, poor moisture content, inade-
quate compaction, adverse weather, etc’., he will be empowered to
either stop construction until the conditions are remedied or correctd
or recommend rejection of the work. ,.
- Soil tests used to determine the degree of compaction will be perforlneii
in accordance with the following American Society for Testing and Mat-
erials test nwthods :
Maximum Density & Optimum Moisture Content - A.S.T.M. D-1.557-70
Density of Soil. In-Place - A.S.T.M. D-1556-Gd
mwAm'rroN OF AREAS TO - RECEIVF~ FILL
All vegetation, brush an? debris shal.1 be removed, piled and burned
or otherwise di-sposed of. After clearing, the natural gr0u11d shall he
scarified to a depth of 6 inches, brought to the proper moisture con-
tent, compac:t.ed and tested for the minimum density specified in the
Spxial Provi~sions or the recommendation contained in the preliminary
soil. inves-Ligati.on report. -
\\'hen the slope of the natural ground receiving fill exceeds 20% (5
horjzontal units to 1 vertical unit), the original ground shall he
stepped or benched. Benches shall. he cut to a firm competent soil
condition, The lower bench shall be at least 10 feet wide and all
other benches at least G feet wide. The horizental portien of each
bench shall bo compacted prior to receiving fill 8s specified herein-
before for compacted natural ground. Ground slopes flatter than 20% '
shall be enched when considered necessary by the soil engineer.
I?ILL MATERIAL
Materials placed in the fill shall be approved by the soil engineer
and shall be free of vegetable matter and other deleterious substances.
"
.- Granular soil shall contain sufficient fine material to fill the
- voids. The definition and disposition of oversized. rocks, expansive
and/or detrimental soi.ls are covered in the Special Provisions. Ex-
pansive soil.^, soils of posr gradation or strength characteristics may
he t.horoughly mi.xed wit.h other soil~s to provide satisfactory fill n?at-
erial~, but on1.y with the explicit consent of the soil engineer.
PLACIXG AND COMPACTTON OF FIIJ,
"" -
Approved fi1.1 material shall be placed in areas prepared to receive
fill in layers not to exceed 6 inches in compacted thickness. Each
layer shall have a uniform moisture content in the range that will
allox the coinpaction effort to he efficiently applied to achieve the
specj fied deqrce of compaction. Each layc~r shall be uniformly com-
~zctcd to 2. mj.nin!:~m spc:cifi,ed density with ndequate1.y sized erjuipnwl:t,
either specifically desi.<~ned for soil co~~~pacti.on or of proven relia-
bility. The minimum degree of compaction to be achieved is specified
in either the Special Provisions or the recommendations contained in
the preliminary soil investigation report.
-
Field tests'nnd inspections to check t.he degree of compaction of the
fill will be taken by the soil enqineer or his representative. The
location and frequency of the tests shall be at the soil engineer's
discretion. 1x1' general, the densi.ty tests will be made at an inter-
val not exceeding 2 feet in vertical rise and/or 500 cubic yards of
embankment.
. ..
APPENDIX A, PAGE 4
- SEASOY LIMITS -__
Fill shall not he placed during unfavorable weather conditions. When
work is interrupted by heavy rain, filling operations sha1.l not be
resumed until the proper moisture content and density of* the fill has
been achieved. Damage resulting from weather shali be repaired bc-
fore acceptance of work.
UNFORESEEN CONDI7.’l:G?IS
In the event that conditions are encountered during the site prepara-
tion and construction that were not encountered during the prel.imina~-y
soj.1 investigation, Sout-hcrn California Testing Laboratory, Inc. assu~c:~
no responsi.bili.ty for condit-ions encountered which differ from those
conditions found and dcscribed in tYle preliminary soil investigation.
-
Dct.ri.mcntza1J;r "_ .- expansive "- soi1.s is d-fined as soil which will swell
more than 3 paercent against a pressure of 150 pounds per square
foot from a condition of 90 percent density and optimum moisture
content to saturation.
OX-ey:.j.zcd Fill. _I_ matcri.al is defincd as xock~ or lumps over six
inches in diameter. At ].east 40 percent of the fill soil shall
pass tflro~agh a No. 4 U.S. Standard Sieve.
SOTL DESCRIPTION
UNIFIED SOIL CLASSIFICATION CHART
. COARSE GRAINED, More than
half of material is laroer
than No. 200 sieve-size.
;RAVELS
Lore thsn half of
:oarse fraction is .arger than No. 4
,ieve size but
CLEW GRAVELS "
maller than 3". GRAVELS WITH' FINES
of fines)
(Appreciable amount
'RNDS " CLEAN SANDS :ore than half of
lnaller than No. 4
oarse fraction is
ieve size. SANDS WITH FINES (Appreciablc aniount of fines)
-1. FINE GRAINED, More ,than
half of material is Emller than No. 200 sieve size.
SILTS AND CLAYS
Liquid Limit ' , less than 50
SILTS AND CLAYS
Liquid Limit greater than 50
HIGHLY ORGANIC SOILS
GROUP SYPIOL
,"
Gw
GP
GM
GC
sw
SP
SM
SC
.,
ML
CL
OL
MH
CH
on
PT
0 ,' TYPICAL NILhlES
Well graded gravels, gravel- sand mixtures, little or no
fines ;
sand mixtures, little or no Poorly graded gravels, gravel
fines.
Silty gravels, poorly graded
gravel-sand-silt mixtures.
Clayey gravels, poorly graded gravel-sand, clay
mixtures.
Well graded sand, gravelly sands, little or no fines.
Poorly graded sands,gravelly
Silty sands, poorly graded
sands, little or no fines.
sand and silt mixtures.
Clayey sanas, poorly graded
sand and clay mixtures.
Inorganic silts and very
fine sands, rock flour, sandy
mixtures with slight plast-
silt or clayey-silt-sand
icity
Inatganic clays of low to
medium plasticity,gravelly
clayk, lean c1ays. claya, sandy clays,silty
Organic! 5Slts and organic silty clays of low plasticity fnorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts.
plasticity, fat clays.
Inorganic clays of high
organic clays of rnadiurn to high plasticity.
Peat and other highly organic soils.
SOUTHERN CALIFORNIA
TESTING LABORATORY