HomeMy WebLinkAboutCT 71-03; RICHIE GLEN SUBDIVISION; PRELIMINARY SOIL INVESTIGATION; 1971-10-22c..f71-03
SOU THE R N CAL I F" 0 R N I ATE S TIN G LAB 0 RAT 0 R YIN COR ,p 0 RAT E 0
6280 RIVERDAL.E ST. SAN DIEGO, CAL.IF". 92120 • TEL.E 280-4321 • P.O. BOX 20627 SAN DIEGO, CAL.IF". 92120
73-038 HIGHWAY 111 PAL.M DESERT, CAL.IF". 92260. TEL.E 346-1078
678 ENTERPRISE ST. ESCONDIDO. CALIF". 92025. TEL.E 487-2662
Bee Cee Cempany
3095 State Street
Carlsbad, Califernia
Octeber 22, 1971
92008
seT 21258
Repert NO'. 1
Attentien: Mr. Leu Chase
SUBJECT: Preliminary Seil Investigatien fer Richie Glen Subdivisien,
Tamarack Avenue, Carlsbad, Califernia.
Gentlemen:
I-n 'ac'c'O'rdance with yeur request, we have perfermed an inve's,t'iga-
tien ef the seil cenditiens at the site ef the subject 'subdi visien.
We herewith submit a repert ef this investigatien.
The analysis ef eur findings is intended to' previde the required
infermatien fer the preparation, grading and develepment ef the
site and the design ef feundatiens thereen.
In,general, we feund faverable seil cenditiens and we recemIhend
that the previsiens centained in the bedy ef this repert be fellewed.
If yeu have any questiens after reviewing eur repert, please de not
hesitate to' centact this effice.
This eppertunity to' be ef service is sincerely appreciated.
Respectfully submitted, '
SOUTHERN CALIFORNIA TESTING LAB., INC.
IP: j Ie
cc: (5) Submitted
(2) SCTL, Escendide
'l
INSPECTION • TESTING • RESEARCH • DEVELOPMENT
6280 Riverdale st. • San Diego, California 92120 • Phone 280-4321
ALL REPORTS ARe: SUBMITTED AS THE CONFIDENTIAL PROPERTY OF CLIENTS. AUTHORIZATION ,.OR PUBLICATION OF OUR REPORTS, CONCLUSIONS, OR EXTRACTS
,.ltOM Olt REGARDING THEM IS RESERVED PENDING OUR WRITTEN APPROVAL AS A MUTUAL PROTECTION TO CLIENTS, THE PUBLIC AND OURSELVe:S.
REPORT OF SOIL INVESTIGATION
RICHIE GLEN SUBDIVISION
·T:A:M-:A:-RAGK AVENUE
CARLSBAD, CALIFORNIA
1. PROJECT DESCRIPTION AND SCOPE
This report presents the results of our soil investigation for the pro-
posed s-ite of Richie Glen Subdivision located at Tamarack Avenue within
the approximate boundaries ind~cated on the attached plot plan (Plqte No.
l}.
A brief legal description of the site is that portion of Tract 241 Thurn
Lands, in the County of San Diego, State of California, according to Map
thereof NQ. 1681 filed in the office of the County Recorder of San Diego
County, December 9, 1915.
It is our understanding that one and two story, woodframe structures are
planned for the site.
The investigation was undertaken to:
a) Determine the physical properties of the prevailing soils,
including their supporting capability" expans,ive potential
and settlement characteristics.
b) Provide design recommendations regarding site preparation
and foundations.
\
<. Sc!;T 21258 October 22, 1971 • Page Two
2. FINDINGS
The site is relatively flat with a gentle westerly slope. 'Three buildings
presently exist on the site; one in the southeastern portion and t.wo along
the western portion of the property. There are trees along the eastern
and southern limits of the property. The remaining portions of the site
have been disced and brushed.
The 's':tt'e -j:s 'unde-rlain wi'th silty -me'd-iumsa:nd. The 'sur'face one foot of the
sand is loose. Below this depth, the s'and is medium to very dense'.
3. RECOMMENDATIONS
3.1 Ea~thwork and Grading
All 'earthwork and grading anticipated for the site should be accomplished
in accordance with the attached Recommended Grading Specifications.
3.2 Slope Stability
Cut 'and fill slopes not exceeding total height of ten feet may be constructed
at or flatter than a slope ratio of 1.5 to 1.0 horizontal to vertical
units. ..
3.3 Foundations
3.31 General: We recommend conventional spread footings ,for the,support
of the proposed structures. Conventional spread footings should have a
minimum depths of 12 and 18 inches below 'the lowest adjacent finish grade
for one and two story structures, respectively. Continuous footings should
'have a minimum width of 12 inches; Square and circular footings should
have a minimum width or diameter of 24 inches so that the bottom of the
, footing excavations may be property cleaned.
·seT 21258 October 22, 1971 • Page Three
3.32 Allowable Bearing Pressures: Allowable bearing pressures of 1,500
and 2,000 psf may be utilized for footings founded 12 and 18 inches
deep, respectively. These pressures may be increased by one third for
wind and/or seismic loading and should be reduced one fourth for dead loads
only.
3.33 Lateral Resistance: The passive earth pressure and/or the coefficient
'of 'sl"irring i'ri'c"tion b'etweene-oncret'e ·al'lds·oil may be assume.d to resist
lateral movement.
Coefficient of sliding friction between soil and concrete may be assumed
to be 0.40. The passive pressure may be assumed to be equal to 200 psf
at the surface and to increase at a rate ·of 150 psf· per foot'of depth.
This value of passive resistance is computed assuming no surcharge and a
1,e:v;eJ. fini.s.h .grade adj.a.ce.nt tD t.he resist.ing .e.l.e,ment. Tf t.he ant,ic.ipated
conditions are otherwise, this office should be contacted for revise4
values.
3.4 Settlement Considerations
To avoid excessive differential settlements, it is recommended that adja-
cent footings founded at different bearing levels be locate.d such that the
slope from bearing level to bearing level be flatter than one horizontal
to one vertical. The above provision, along with the bearing value. re-
commendations of Section 3.32, limits total and differential settlements
to approximately 3/L~" and 1/4", respectively.
3.5 Expansive Soils Considerations
Since the prevailing soils are not detr~mentally expansive, no special
precaution with regard to expansive soils is required.
SCT 21258 October 22, 1971' Page Four
3.6 Retaining Structures
Lateral earth pressure on retaining structures. which are unrestraine.d at
the top may be assumed to be equivalent to that. of a fluid weighing 35 pef.
Lateral earth pressure on restrained retaining walls, such as basement
wall~, may be assumed to be equivalent to that of a fluid weighing 55 pcf.
4. FIELD EXPLORATIONS
Four subsurface explorations were made at the locations indicated on the
attached plot plan. The explorations were made. on October 12, 1971. They
consisted of trenches excavated by means of a backhoe operated under the.
direct supervision of our engineering geology personnel.
The explorations were carefully logged when made. The logs are presented
on Plate Nos .. 2, 3 and 4. The soils are described in accordance with the
Unified Soils Classification System as illustrated on the attached simpli-
fied chart; In addition, a verbal textural description, the wet C010T,
the apparent moisture and the density or consiste.ncy are given on the logs.
Soil dens~ties for granular soils are given as either very loose, loose,
medium dense, dense or very dense.
Representative chunk and bag samples of typical and representative soils
were obtained and returned to the laboratory for testing.
5. LABORATORY TESTING
Laboratory tests were performed in.accorqance with generally accepted
American Society for Testing and Materials (A.S.T.M.) test methods' or
suggested procedures. Representative samples were tested for' their gra-
dations, shear strength parameters and maximum densities. The results
of these tests are presented in tabular form on Plate Nos. 5 and 6.
Natural density and moisture contents were determined from undisturbed
chunk samples and are tabulated on the boring logs.
ADAMS
ST.
,
144
LOCATION MAP !
no scale. /
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HIGHLAND
ST.
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TAMARACK AVE.
a~test trench location
SOUTI-IERN CALIFORNIA TESTING
LABORATORY, INC.
6280 RIVERDALE STREET
SAN DIEGO. CALIFORNIA 92120
714-280-4321
PLOT PLAN
Richie Glen Su~division
Tamarack Avenue
Carlsbad; Caliornia
BY DATE 10-22-71
JOB NO," 212 8
1 I
, '
I
o
2
4
6
10
12
e • TRENCH NUMBER 1
CLASS DESCRIPTION
I . SM Dark Brown, Dry, Loose, SILTY
," ' ' ~ fJIedium SAND ' ..
" :' .: -;. ,
" ", -, " ,
t ~ ... -' " ' , I -' , ..
; 'I ',' -' , ' " ~
, " , -. '4
, " " \-.. , -. , ''', .. ',' , . , ' . . '--\ , .,", ' , " -, "
" , -, , , .
SM Brown,
T'-'Iedi um
Sand.
SM Brown,
Medium
Dry to Humid, Dense, SILT
SAND With Pockets of Clea
Roots to 3.5 feet.
Humid, Very Dense, SILTY
SAND
Y
n
, , . ~ , .. "
LEGEND:
~: Sample Location '
Y: Natural Dry Density (pcf)
M: Natural Moisture Content (% of Y)
SOUTHERN CALIFORNIA TESTING
LABORATORY, INC •.
,
Richie Glen,'Subdiv~sion
Tamarack Avenue
Carlsbad, ,California 6280 RIVERDALE STREET
SAN DIEGO, CALIFORNIA 92120
714-280,4321
TRENCH LOG BY r.1RF DATE 10-12-71
JOB NO, 21258 PLATE ' ?
I·, r
, I 1 II
I
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t
l t I f I·
t
t-
f
t I-,.
j
I I I
-I i I , -. '
I I
.'
2
4
6
8
10
o
2
4
6
8
10
titRENCH NUMBER 2
CLASS DESCRIPTTON -Y M
r" ." ' .. " Dark Brown, Dry, Loose, SILTY ~ , ' SM " I·: .' . " r~ Hedium SAND I" ,1
" ' .. · .O''' " , , " SM Brown, Humid, Dense SILTY Medium -" SAND ~"ith Clean Sand Pockets and
107.8 i.4
',' Roots -, .. •
f " ' " SM Reddish-Brown, Humid, Dense to ~ , .' I ' Very Dense, SILTY Medium SANP • eo ..
105.6 2.5
~ ':, " .. ;0 ..
to" • ~ -: ' , , ,
, ' , -, · , .', , ~ .
! "i
l. , ... ;
,\ J
~ , " , , t
TRENCH NUMBER 3
.... '. " , SM Dark Brown, Dry, Loose SILTY ." ". , ,
£ :' ' " I'" Medium SAND " .. ' . "
I ": ":, " SM Brown, Dry to Humid, Medium Dens : :'-
.. , " ~ " ''', e
SILTY He-dium SAND \-lith R'oot·s , ...... :': :" I -, ' " · . " SM Brmvn, Humid, Dense to Very Dens e -, SILTY Medium SAND " . , Ed ..
, ' -' .. " I . ,
-, , -.:. ~ , ,
' : " . -: " :
" • I,
SOUTHERN CALIFORNIA TESTING
LABORATORY, INC:
6280 RIVERDALE STREET
SAN DIEGO. CALIFORNIA 92120
714,280,4321
115.4
Richie Gle~ ,Subdivision
Tamarack Aye-nue
Carlsbad, California
7.1
TRENCH LOGS BY rllRF DATE 10-12-71
JOB NO, 21258 PLATE NO.' 3
OJ'
I ,I
'0
2
4
6
8
10
-TRENCH Nm.mER 4
CLASS DESCRIPTION Y
':, •• 0' • o' -. . " SILTY " ., " SM Dark Brown, Dry, Loose ~ ,I .' .; Medium SAND : ", ", : . . ".°,
r .. ,
Dense .. , SM Brown, Humid, , . I:~ , , ' " Dense, SILTY r1edium ,. "~
" " , . , , -" [.>' • .. .. ' -. ! . , , . I , -~ ,I. :.
~ " , -" ... , .. -.
-
.~' ~ . , ". ,.
SOUTHERN CALIFORNIA TESTING
LABORATORY, INC.
6280 RIVERDALE STREET
SAN DIEGO. CALIFORNIA 92120
714-280-4321
to Very
SAND 117.5
"
Richie Glen Subdivision
Tamarack Avenue
Carlsbad, Californ~~
7.2
TRENCH LOG 'BY MRF DATE 10-12-1
JOB NO. 21258 PLATE NO. 4
. I
,
. DIRECT SHEAR 1ST RESULTS
..
Angle of Cohesion SAMPLE DESCRIPT ION inte rna I int~rcept
frict ione 0) (pst) ,
T2 .@5-6' Sample Remolded to Natural Density 29 1.20·
T2· @5-6'f Sample Remolded to 90% of Maximum 37 24.0
-
... --.,
. .
,
MAXIMUM DENSITY & OPTIMUM MOISTURE CONTENT
AST M15.5J ....... METHOD; .... A .......
" 'Maximum optimu m SAMPLE DESeR/PT JON DC'ns ity Moistu re (pet.) ContC%) ..
T2 @5-6' Reddish-Brown, Silty Meqium Sand 132.5 8.5
'" ..
. .
SOUTHERN CALIFORNIA TESTING
LABORATORY, INC. Richie Glen Subdivision
6280 RIVERDALE STREET Tamarack Avenue ..
SAN DIEGO. CALIFORNIA 92120 Carlsbad, California· 714·283·6134
TABLES OF TEST RESULTS BY DG DATE 10-19-71
JOB NO. 21658 PLATE NO. 5
. GR,AIN SIZE ~ALYS IS +'ATTE~RG 'L 11\11 I,T5 <
-( U.S. Std Si ev.es)
T2 @ T3 @
SAMPLE 1.5-2.5' 1.5-2.0'
.,.,...=wn'yft'''''''''''
6 11
3/1 , '
1/
'1 1/2
3/4 11
1/ 3;1~5 100;0 100,0
'Z #4 99.7 98.8 4J c
98.7 il:-#B ,99.5
..... '~ #16
u 99.3 98.5
(,.
~ #30 95.5 94.1
""
c #50
0 61.1 6 cr'. 3
+' #100 36.1 34.6 ro
1::l 'ro .... , ' , , --, '
(,. ::/1200 26.5 . <.9 27.3
.05 mm'
.005mm'
.001 mrfl
LiquJd ,Limit
Plast ic Limit
Plast i city Index NP NP -
CLASSI FfCATlON SM SM , '
"
, , .
, ,
SOUTHERN CALIFORNIA TESTING
LABORATORY, INC. Richie Glen Subdivision
6280 RIVERDALE STREET Tamarack Avenue
SAN DIEGO, CALIFORNIA 92120 Carlsbad, California 714-283-6134
TABLE OF TEST RESULTS BY DG DATE 10-19-:-71
JOB NO. 21258 P_LATE NO 6
, "
oL. ... _ .... ..-._1. • ..., _ .. <I.... •• " ... • .... __ .....
RBCOM~EP. ~RADnIP SP.E.CIF.I~T.IONS -. GENE,R1\L&OV,ISIONS
GENER1\L INTENT: ---... . . ---
If: .
The tntent of these specifications is to establish procedures, for clearing;
compactin'g natural ground, preparing areas to be filled' and placing and com-
pacting fill ,soil to the lines and grades shown on the accepted ,plans. ~he
recommendations contained in the preliminary soil investigation report and/o~
, ,
the attached special provisions are a part of the recommended grading speci-
fications and shall supersede the provisions contained hereinafter, in the
cg.s~ .of oQnf.li.ot,.
INSPECTION AND TESTING: ..-..... _. 1 * ........
A qualifie,d soil engineer shall be employed to inspect ahd test the earthwork
in accordance with these specifications. It will be necessa'ry that' the' soil
engineer.or his representative provide adequate inspection so that, he may
certify that the work was or was not accomplished as specified. It shall
be the re~ponsibility of the contractor to assist the soil· engineer and to'
keep him appraised of work schedules, changes and new information and data
so that he may make these certifications.
If, in the." opinion of the soil engineer, substandard conditions are encount-' .. -
ered, such as questionable soil, poor moisture control, inaq~quate compactj.on,
adverse weather, etc., he will be empowered to either stop construction until
the conditions are remedied or corrected or recommend rejection of the work.
Soil tests used to determine the degree of compaction will be performed in
accordance with the following American Society for Testing and Materials
test methods:
Maximum Density and Optimum Moisture Content. A.S.T.M. D~1557-70.
Density of Soil In-Place A.S.T.M. D-l556-64.
-.... ----.... ,--
--.
PREjPA.R'.lTION, ,OF ARE~U.Q..E.~--1:~
Al,l vegetation, brush and debris shall be removed, piled and ,burned or other-
wise disposed of. After clearing, the natural ground shall be scarified to a
depth 6f 6 inches, brought;. to the proper moisture content, compacted alld" tested
for the minimum density specified in the special provisions 'or the recommenda-
tions contained in the. preliminary soil inves,tigation report~ _
Wnen the slope of the natural ground receiving fill e~xceeds 20"10 (.5 ho.rizontal
to 1 vertical), the original ground shall be stepped or benched.,Benches:-
shall 'be cut to a firm competent s011 condition. The 'lower bench shall be at
least 10 feet wide and all other benches at least 6 feet wide. The horizontal
portion of each bench shall be compacted prior to receiving fil-l as specified
hereinbefore for compacted natural ground. Ground slopes flatter than 20%
shall be benched when considered necessary by the soil engineer.
FILL MATERIAL:
'Mat-e'ri-ai's placed intlle -fill shall-be 'approved by the sO'il engineer ~nd shall
be free of vegetable matter and other deleterious substances. Granular soil
shall contain sufficient fine material to fill the voids. T4e def~ition and
dispositior; of oversized ,rocks, expansive and/or detrimental soils are covered' ..
in the special provisions. Expansive soils, soils of poor gr~dation or
strength characteristics may be thoroughly mixed with otner soils. to. provide
satiSfactory fill material, but only with the explicit corisentof the soil
engineer .•
~~ING ANP COMPACT~ON pF FILL:
Approved fill material shall be placed in areas prepared to rec'eive fill in
laye;rs not to exceed 6 inches in compacted thickness. Each layer shal:l have
a uniform moisture content in the range' that will allow the compaction effort
, _.
.. . -..... --:;-;.;;-;;..;--;;";;-'.,--.,..--.-.. , ... -__ .o..J. L... -c.... :J __ • ' ..
to -be efficiently apPlieao achieve the specified egree of compaction,~
Each layer shall be uniformly compacted to a minimum speci!ied density
with 'adequately sized equipment, either specifically designed for soil
compaction or of proven reliability. The minimum degree of compaction
tob~ achieved is specified in either the special provisions or the re-
I-commendations contained in the preliminary soil investigation report.
Field tests and inspections to check the degree of compaction of thefili
will be taken by the soil engineer or his representative. The location
and frequency of the tests shall be at the soil engineer's discretion. In
general, the density tests will be made at an interval no·t 'exceeding 2' feet
in vertical rise and/or 500 cubic yards of embankment.
pEASO~ LJN~
Fill shall not be placed during unfavorable weather conditions. When work
," is interrupted by heavy rain, filling operations shall not be res.Ulned until
·the proper moisture content and density of the fill has been achieved. Dam-
age resulting from ''leather shall be repaired before· acceptance of work;
tr~ORESEEN CONTI !TIONS : _ _ .... 'Ii
• In the event that conditions are encountered during the site preparation
and construction that were not encountered during the preliminary soil iri ...
vestigation, Southern California Testing Laboratory, Inc. assumes no respon-
sibility for conditions encountered which differ from those conditions found
and described in the preliminary soil investigation ·report.
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