HomeMy WebLinkAboutCT 72-24; SPANISH VILLAGE WEST; SOILS INVESTIGATION; 1972-02-17. ,
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SOILS INVESTIGATION
, Proposed Borrow Area
Southeast Comer of the Intersection of
EI Camino Real and La Costa Avenue
~a Costa, California
for
La Costa Land Company
Proiect No. 72-1-11A
February 17, 1972
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BENTON ENGINEERING, INC.
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PHILIP HENKING BENTON
PRESIDENT .. CIVIL ENGI~EER
IntrC?duction
BENTON ENGINEERING. INC.
APPLIED SOIL MECHANICS -FOUNDATIONS
6741 EL 'C,AJON BOULEVARD
SAN DIEGO. CALIFORNIA 9.2115
. SOILS lNVESTIGATION
SAN DIEGO: 583"~t.'4
LA, MESA: 469-~~$"
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This is to present th6. re~vlts of a soils investigation conducfed at the proposed cut slope
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area located at the southeast comer of the intersection of EI Camino Real and La Costa Avenue,
La.Costa, California.
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It is understood th~f)th,prc>posed cut,slope was plannedodslnally to b, at 2hodzontal
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to 1.0 vertical slope up to 50 feet in heig'ht with a 1 o feet .wide' bench near midpOint •. The
... e~cavated materials will ~ ,~d as an imported fill for the.'con,struction use of th. P~PO$ed :
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Shopping Center Plaza sifu~l~d northerly of the ptop<)$ed cut aSw~1I as La Costa Av.enue.
The objectives of tJ~j ·investigation were to determine the ~xlsting soil cOr:i~itions in_.t~ . ..
proposed cut slope areas and their physical properties in order that recommendations could be pre-
~.nted, for ,0 stable cut slope .• AlsO: to determine the soi tcibi·li·ty· of, 'the soils for use as. compacted
·fUI. In or.der to accompli.tuth~.:ob:iectives,.three borrng' ~re.drilled along the~tOe of the· cut
slope areas and represel'):tOtt~e und.isturbed· and' loose bag samples were taken. for laboratory testing ..
Field Investigation
Three borrngs we"',.dtilled with a truck-mounted rotary buCket type drill rig at the approx!'"
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. 'imate location$shown on 'the·attachtd Drawing No.1; entitled'IILocatJon of Tesf-Borings.1l T.he
borings were drilled to.depth$.of 51.0 to 58.0 n.t below the existing ground surface. A contin-. , .. .
uous log of the soils encountered In the borings was recorded qt tbe time of drill ing and is shown
in detail on Drawing Nos.2to 10; Inclusiv8,e.ach entUledll$ummary Sheet.1I A field engineer
was lowered tnslde the -Open· holes to check the bedding and dip of contact surfaces betweenthe
t varous soil strata • ..-
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-2-• The soils were visually classified by field identification procedures in accordance with
the Unified Soil Classification Chart. A simplified d",cription of -this classification system is
• presented in the attached Appendix A at the end of this report.
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Undisturbed samples were obtained at frequent intervals, where possible, in the soils
a~eadof dri II tns. The drop weisht used for driving the sampl ins tube Into the soils was the
"Kelly" bar of the drill rig which weighs 2200 pounds, and the overage drop was 12 inches.
The general procedures used in fleJd .sampling are described under II SompUng li in AppendlxB.
Laboratory Tests
Laboratory tests were performed on all undisturbed sampl. of the solis in order to deter-
m~ne the dry density, moisture content, ands~rfng strength. The results of these tests are
• pr.sented on Drawing Nos, 2 to 10, inclusive.
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Consolidation tests were performed on represelitattvel~ bagsamp.leS compacted to 90
. * ptlJrcent of their maximum dry density In order to determine the compressible characteristics of the
remolded sampl:esand the "",suits of th~se tests are presented graphically on Drawing Nos. 11 to
13, inclusive,·each entitled "Consolidation CurVes."
The general.proc&du ... s u$8d for the laboratory tests are ~ctibed briefly In AppendiX B.
In addition to the above laboratory tests, expansion tests were performed on some ·of the
. claYEty $Oils, both undisturbed and remolded samples, encount~ to determine their volumetric
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,~hasige charaeterl$Hcs with qhange In1molsture content. The rec:o.rded expansions of the satnpl81
are p ... ented on the following page.
* It should be noted that when water was permlttecl to contact the remolded samples,
three ·of ,these were fourid to expand as indfcatedby the + symbols on Drawing Nos.
11 to 13, inclusive,. rather than consolidate.
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BENTON ENGINEERING. INC.
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eXPANSION TEST RESULTS
Percent Expan$ton
Under Unit Load of
Sample 60 Pounds per Square
,Boring or Bag Depth In Foot from Field
No. No. (Feet) Soil Description N.otsture to Saturation
(A) Undisturbed Samples
1 10 46.0 Silty clay, gray:tsh 7.15
{8) Remolded (Remolded. to 90 Percent f.Aaximum Dry Density
per A.S.T .M. 0 1557-66T Method)
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Boring
No.
SampJes
3
5
8
10
Bag
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39.0-40.0'
13.0-14.0
29.0-30.0
38~0-39.0
Depth in
(Feet)
Slightly clayey very fine
to finG sand .
Silty clay, light gray and
brownIsh or olive brown
Clayey very fine sand, light
gray and yellowish
Silty clay, greenish gray
Soil Description
Surcharge
(Pounds Per
Square Foot)
0.74
12.38
3.62
14.99
Percent Expansion
Under Surcharge
In 'the Water
(C) Re$ults of Expansion From ConsolidatiQn Tests of Remolded Samples
(Remolded to 90 Percent of Maximum Dry Denl~ity per A.S.T .M· •. b 1557-66T Nethod)
3 5 13.0-14.0 Sil ty clay, light gr9Y and 200 10.63
brownish or olive brown 600 9.83
1000 8.67
2000 5.69
4000 1.39
3 8 29.0-30.0 Clayey very fIne sand 200 2.51
light gray and yellowish 600 2.10
1000 1.50
2000 0.50
3 10 38.0-39.0 ,Silty clay, greenish 200 10.83
gray 600 10.08
1000 8.51
2000 5.01
4QOO 0.80
BENTON ENGINEERING, INC.
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• BENTON ENGINEERING. INC.
-5~ • SATURATED AND DRAINED DIRECT SHfAR TEST RESULTS
Direct shear tests Were also pes:fonned on both undisturbed sampleS and on the 100$~
• repr_ntatlve sampl. remolded to 90 percent of the maximum dry: density and saturated and
drained prior to testing, 'In order to obtcitn strength characteristIcs of the solis when reco~cted
and subfected to increased moistu .... content. Tne, results of these direct shear tests are presented
• as follows:
, (A) Undisturbed Samplel
• Angle of
Normal, Shearing Internal Apparent
Boring Sample Depth' Load , ' Resistance Friction CoheSion
No.,' No. (Feet).' Soil Description (kips/sq ft) . (ktps/sq ft) (Degree) lb/sq ft
• 2 -7 31.0 51,1 ty clay, grayish 0.5 0.93 35.5 660
'brown 1.0 1.47
2.0 1.92
2 10 46.6 Silty clay, greenish 0.5 1.25 29.5 970
'gray 1.0 0.81 • 2.0 2.10
2 11 51.0 ' Silty clay, greenish 0.5 0.61 40.5 150
gray 1.0 1.05
2.0 2.17
• 3 3 12.0 Clayey very fine 0.5 1.63 39.0 480
sand reddish brown 1.0 2.77
2.0 2.86
• 3 4 16.0 Si I ty clay, gr:ayish 0.5 1.49 14.0 1270
brown 1.0 2.58
2.0 2.17
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BENTON ENGINEERING. INC.
-6-'. ~ (8) Remolded Samples
Angle of
Normal' ,Shearing Infernal ,Apparent • ' "j80rtng Bag Depth Load ReSistance FrictJon Cohesion
No" No. (Feet) Soil Description , (kips/sq ft) : (kiPs/$q ft-) : (Degree) (Jb/sq ft)
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1 1 18-.0-19.0 Very fiRe sand 0.5 0.51 ,37.2 150
1.0 0.94
:. 2 •. 0 1.62
1 ' ' , 2 33.0-34.0 Clayey very fine 0.5 0.48 31.0 -40
sand I ight gray 1.0 0.59
2.0 1.27
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i 1 1.0-2.0, Clayey very fine, 0.5 0.54 22'~0 360
to fine sand, light 1.0 0.86
'gray and brown 2.'0 1.07
. ~"-2 3 39.0-40.0 51 ightly clayey very 0.5 0.46 38.0 93 • ~~ "'-fine to fine sand, light 1.0 0.90
9rQY and reddish brown 2.0 1.60.
a 3 4.5-5~5 , Clayey very fine sand 0.5 0.46 4O~() 40
light red and brown 1.0 0.88 • 2.0 1.74
3, 4 6.5-7.5 . Clayey very fine sand 0.5 0.52 37.0 150
light yellowish brown 1.0 1.00
2.0 2.00
• Silty clay, lightg,ray 3 5 13.0-14.0 0.5 0.61 9.0 540
and brown 1.0 0.71
2.0 0.85
• 3 8 29.0-30.0 Clayey very fine sand, 0.5 0.54 25.0 280
light gray with yellow 1.0 0.77
and red brown 2.0 1 ~31
3 10 38.0-39.0 Silty clay, greenish 0.5 0.61 9.0 550
gray with red 1.0 0.46 • 2.0 0.85:'
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BENTON ENGINEERING. INC.
-7-• UNCONFINED COMPRcESSION TESTS
Unconfined compression tesl$ were perfOrmed on selected samples of the residual soils
• of the claystone and sandstone in order. to determine the stren9~h chatactedstics of the forma-
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tions and to detect, if any, possible weakp!anes within the sompJes from interpretation of the
recorded stress-sttain relationships during te!its. The testing specimens had a I.,ngth 9f 5.0
• inches and a diameter of 2.5 Inches. AxiQI loads ~re applied in increments, and deflections
was recorded until the samples fQtled. The testing..-ults aresh()wn as follows:
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Unconfined
Compression' Strain At
Boring Sample Depth Strength Yield Point
. No. No • (fe$t) Soil Description (Ib/sq ft) (Percent)
'1 8 36.0 SUty clay, yellowish 12,420 1.6
brown
1 9 41.0 SU ty clay, greenIsh 8,290 • 1.5
S 6 24 O' .. gray
'SIIty clay, gray and 10,360 1.84
brown
TRIAXIAL COMPRESSION TESTS
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(Unconsolidated and Undratned~
TrtaxJal compressi9n tests were perfo~ on sel.cted samples of the grayish silty clay . ~. , .
:soi{~ derived from the san$::ioccil weathered mud$tone. Tn. $.qi)1pi:,., Were 5.0 inches high and
laterally loaded by glycetbte preS$ure against a membrqn~;: qxiaH~ were applied to the ends,
, .:Of t~~ samples in· Jncreasi:ng inorements until failure. Telts were performed unconsolidated and
'u!1drcdned condition. T~ PY'rpOse of this test is to determl;m~> theia~Qrent cohesion and the
.~gle ofintemal frIction :til the ~k.t planes of the $Oils whioh rn.ight h~e been caused by
previous l~ndJlide or earth movement In that area. T~ re5ulb.' of the hlSts are shown
011 .the following page.
BENTON ENGINEERING. INC.
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DeyiQtor Stre5$
Conf.inlng Dev·fetor Stress At Maxf.mumRatio
Bortng Sample Depth Pressure At Yield Point Of Principal Stresse$
No. No. (Feet) . (~i) {psi} (psi)
3 11 44 .. 0 33.6 36.2 43.2
3 13 53.0 40.4 89.4 94.0
3 14 58.0 44.2 36.1 80.4
The angle of Intemal friction and the apparent cohesion of the grayish ahc:J 9re~nish silty
clay soils tested are on the average of 7.5 degrees and 2845 pounds per square foot under field
• moisture condition.
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DISCUSSION, CONCLUSIONS AND R~COMMEN DATIONS
Soil Strata
"n general, the 5o~ls encountered in the three drilled hol~. are the residual soHs of local
, muddy sandstone and clays;fone which are described as slightly clayey to clayey Y~ry ,fine toftn.
• sand, and silty ~Iay tn engin(tering claS$ifications.
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In Boring 1, medi~in, loose to firm clayey very fine to ,fine sand was underl:ain at the~pth
'9f 9.5 feet by a firm slightly 'claye,y very fine sand to the depth ~f 20.S feet. F~ctures tn the'
formation were encounter,~.,:dt 2.5 feet. Between the depths of-20.8 feet and 34~5 feeti. the sotls
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consisted primarIly of fi"* clayey very fine sand with lenses of f~cturecf 'silty clay. containing
'I"9Otlets. Very fine to ftn.:.sand lenas. were found. at the depths:*f 14.5 feet arid 16.5 -feet., '
.CongioJn4trate 9 fnche$ thick, and 18 inches long was found-ot:tn. contact $Urfac~(;f 34.5 f.~.
'Below tht_ depth, Q firm slilY clay IlClaystonell wasencountj~ ',to Q ~th of 56~0 f"t,. the:
'Iimit of thfs :expJoratlon •. .the silty day layer was highly frQctured and contain.eeI fron ~tg'ffJ-loind
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gypSum ot the dep.ths beM_n 34~5 feet and 42.5 feet ,Approximately 1 in'ch thrck~ qf
cemented fine' sandy tenses were found at the depths of 45 .• S feet, 48.0 feet and 51 .5 feet.
Scattered Seq ~he.lls and sltck$mlded surfaces were also found at the.·depths between 48.Sfeet
and 51 .0 feet. Distlnctlv, beddfngplanes and incHnQt;ons of ~,tact iUrfac~ between two "
• different matedals were measured in the field and ore tabula.ted on .the foUowi.ng page .• ,
BENTON ENGINEERING. INC.
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Depth
(Feet)
9.0
-11.0
15,;,,5
20:.0
22.,0
,~4.5
Dipping Angle
(Degre.) ,
21.0
lO.O
7.0
6.0
86.0
6~0
No' ground water Wos encountered in' this hole.,
DIpping Direction
Soutli 75 Degrees Toward West
North 58 Degrees Toward East
North 86 Degrees Toward East
SO"'~ 80 Deg"'" Toward East
North 70 Degrees Toward i:ast
. North 47 Degrees 'Toward West
InBoring 2; Q firm clay~'Y very fine sand""with ~rCyish siltY clay lenses was underlain at
19.0 feet by 'a firm silty ciay with 'Ienses of clayey very fine san~ to the depth of 23.5 feet ..
Numerous frciCtu~s were ~~·counter.(nn the 'Clayey ~d formation between the depths of 4.0 . .
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:fQt and 19 .0 feet, CI'ld in the slhy clay between the depths of 20.9 feet and 23.5 feet. ~Iow
• 23 ",5 feet,the soll$ con$isted ptimqrilr. of intermittent layers of cl'~yey very fine sand, silty ~Iay,
and slightly clayey very fine sqnd of varyfng thickn:esseli to th~ end of the hole at 51.0 feet.
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The. s.ifty clay lay~r.below .25.5 feet w~ hiShly fractured wrth iron statns to the depth of
27 .Ofeet.qnd shCtQredJeoieJ Gf 'clayey very flrie sand wHh gypsum was' found hi the silty clay
laYer:at the dtpth of 31.5 ffAet. Numerous fr,actures were ClI50 found. in the silty clay lay~rs . "
bl8~n the depths of 42~:5 feet and 43.6 feet and below 43.6 feet to the end of the hole at
·5:1 .:0 feet.
Distinctive bedding, pJdn~sand inclinations of contact surfaces between two dr-fferent
• materials Qret9bula'ted as follows:
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o.pth
(Feet)
7.8'
11.0'
13.0
10;5
19.0
31.5
DipP.lng Angle
(Degree) "
15.0
81.0
Horizontal Bedding
Vertlccd Iy fractured "
Horizontal Bedding
7.0
No grouhd water was encountered In this hole ..
BENTON ENGINEERING. INc.
Dipping Direction
North 42 Degrees Toward Ealt
South 16 Degrees Toward West
South 60 Degrees Toward West
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In Boring 3, mediumi~e' to firm clayey very ,fine to fine ~qn~ was underlain at the
depth of 11,.7 feet by a silty clay layer to, the depth of 16.5 feet •. Below that depth, a 4.0
f~t' thickness of clayey very ',fine ~nd Was underlain, by fl~ snty,,~IQY wI th gypsu,m seams, and , -l'l.l:-!~. ~
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rost stained tracture$ to the depth of 28.6 feet. Lenses of grayish "II.t clay were found at the . " . ~ ~,' .
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~pth of 20.7. feet. Betwe~n, th. depths of 28.6' feet and 37~~' feet; ftrm clayey $dnd w,qI, '
encQ~ntered. This layer cQl'ltqin~: 14!1i1ses,~f grayish silty day qtth."~pth of 31.7 f.~t, thin,
par,tlngs of very fine to fine s~nd. at 32.5 feet, gypsum ~mj~ ... n 34.5 feet and 34.8 feet
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aod Jtj,"s~ of ,gray silty clay at 36.P-fee't. &.lOw 37.5 fef,: flrm,~ilty clay wi.th gyp$upt seams
,'~d;;r~ri'$iPJ~,~re' en,COVJt.~~'·tethe en~ ~F,~ hOl.',(rt ?$.,Q~:~ .. ~t., tens .. of SCindy ,clay ~nd
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clayey very fine sand werC[l' fourid at'the depthef 46.0 feat. ·:Oistinc:.t.ive bedding planes and
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::: ~tri~liilgtioli', of QQntqct, Sv.i~.'~betw.,n, two d!ff.rtm t 'm9t'rt~&;:wtte~JTI,asured in ,tn.' fl.ld arid:
qte tClbuI dtedas follows:
belj.th
tF~.t~
21.7 eS .. t>
37w:S
Qlpplng Ans1le
:r~re~s)
'l,O,'O,
2.0
22.0
':OIS,cussions and. Conclustof~:" ",
. -, ~<l >" ;
. ::prpptng Dfr~ctfpl'l,
':$~~'t~(~P Dtsr~S:'Towaf~ W,n:
,,:Sq,,~~;~~ ~rees To~t~:r,:t.t: ~,l,I,tH~~O Degr~" Tow<iid:, West . .. ·t, " .
"It is concluded f~;:bur ,fIeld Invest1gation,laborC;ItQrf,tijts and englneer.~tiS,:Qnaly5ti$~
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Ih~t the .fduol spils of ~C;aF,tdstone and claystone do not hqve"~,~~sh strength to s}~nd on a cut
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:$,lop8 50,~O feet In h~Jght!~"(I' ratio of 2 horixotltal to 1 vertfccil. ,:lThe sandstone fOnnati,on which
,i;ittl'l the. form Qf claye.y ;d.'Wos htghly fracti,lred. Th~ sIlty c:I~~materrals derJV~ fFo.m theclay-
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stone have very high expansion potentials and quickly lose strength ,upOn intrQduction of water
.trito the materials even th:$ugn these exhibit a high unconfined 6rxnpressive strength ,(uld cohe$ion . -'. . 'r . . ~ . .
at the present field moistO'r~ contents. The weathered claystone is characteristically light gray to
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gray or greenish gray in c~',~r and contains marty Iron:~,tclthi"dn,d:9y'p$UI'n precIpitates in th.
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fractures. There are innumerable fractures and fissu..escrQaSirtg, th'. beddings In these solis, and
BENTON ENGINEERING, INC.
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they eire frequently slickensided. Many of these structural hnperfectiens are not revealed
until 'the materials a~ falled iii unconfined compressive strength tests and triaxial compressIon
• tests. In the malority of the tested samples, failures foHowed a lagged diagonal Hne through
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the samples on irregular fractures and slickensided planes. The recorded stress-strain curves
indicate a low strain ratio of yield point and relatively flat stress ... strain (:urves beyond that
point. This indicates that thesampl. failed along their weakest planes either along bedding
planes or slickensided surfaces, and therefore, no incred .. in stress wosattc:dned even through
,the loading strain was being increased. An examination of' the faUed samp'les, revealed .the fail-
lire's did occur in these weakest .pIQnes. Some' of the failed samples were immersed in, water I and
were found to disintegrate lnto fragments or soil particl~ in a few minutes. From our previous
• Attethers Limit Tests performed on the similar materials in the vi'crnUy 01 the borrow area, the
liquid limits of these materials far exceedthei'r present moisture content and the materiaJs have
high pladicity indices ranging. from 37.6 percent to 40.4 perc~'"t. This indicates that the • materials are overconsolidated in nature and tend to swell and release abundant energy upon
removal of overburden and introduction of water into the $Qils when excavation is made. The
• energy was pressed into the materials in the post due to overburden, or old tectonic d!sturbances
or'd_icatioil. Upon introduction of water and swellins, the silty clay materials' wHlloose con-
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iiderable -cohesion. In addition, some unfavorable oriemtation of-bedding planes will cause an
·addltional hazard to the slope stability.
Recommendotions
1. C\lt SI3'es
It Is recommended tbclt a 4 horizontQl to 1 vertIcal c::ut slope may be made to a h$ight of
20 feet, and then changed to' 2 horIzontal to 1 vertIcal slope to the top of cut slope to ~ total
height of 50 feet. It is also recommended that a bench 1 0 feet wide be provided in the area
wh.re thesJope changes.
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'A straight slo". of-4 hQri~ontal to 1 vertical with one 10 feet wide bench maybe used,
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in lieu of the cOmbined slQpej des.cribed above, up to a maximum height of 50 f~t.
Th~se recommended dastg" slopes include a fOetor of saf.ty on the order of 1.15,'
:lnci,udJng a seismic factor of o. lEJ.
It is recommended that-paved drainage ditches be provided above the top of slope, at
'. th. insido 9f the:bench and at the, toe,of slope to coUect all surfac.runoff and .conduct fhis
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in watertight drainage pipes aWay from the cut slope. It is recommended that watertight doWn' , .
dJ'ClJns ,be pl'Oyjded throughout to prevent tbe surface water from running over the expOseq slopes.
21' 'The clayey sand soils from the sandstone fonnf;ltion may be satisfactorily used as struc-
turg.1 fills provided the excavated material are properly compacted. The expansive, silty clay.:
• Spils, Qnd green-ish.gray clo)'Stone con 0150 be used as compacted fill but these are not recommended
for structural support iothe compact~ filled ground areas. It would be desirable to place th.,·
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exPansiv~ soil$hi parking are9S only, at 3 feet Qr mo", below:fhe bottom-of pavement.
'The previous reco!TIm~mdations for the proposed Shopping Center present~ in out reporl$
under P~Iect,No. 67-2-17A, and dated April 26, 1967, andlmder Profect No. 69o:-12-23D dated
Octo,ber 14, 1971 will apply.
Respectfully submitted,
BENTON ENGINEERING, INC.
BY~~
S. H. Shu, Civil Engineer
P.viewed G4 '*
Philip H. Benton, Civil Engineer
Dish': (4) Addressee
(2) Attention: Mr" Burton L. Kramer
(2) Rick engineering Company I Carlsbad
BENTON E~GINEERING. INC.
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DATE; i?-/f-72.
PROJECT NO.
72-1-IIA
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f'ROPOS£IJ
BORROW AREA
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.~. Indicates Approximate Location of, Test Boring
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LOCATION OF TEST BORINGS
BORROW AREA
LA COSTA PLAZA SHOPPING CENTER
SAN DIEGO COUNTY, CALIFORNIA
BENTON ENGINEERING, INC •
SCALE: /"= 100'
DRAWING NO.
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o .... . ·s .u. • '. '.;3 , • •
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t-l1li: ,III .. III ... III, II. Do • ...... % aa t-4(=» Do ., z· III a
II» ... II» -c 0 ...
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SUMMARY SHEET
BORING NO.---.l -..-
ELEVATION .JJ4.0' *
. -~. -~ ... Brown, Moist, Loose, Rootlets -.. ..
1 . . . . Firm .
2 , ._' .. .. .. '.' ,
.. .. . 3 ': ~: ; :. light Brown and Light Brown-Red,
, . {,\ :':': :-.: Slightly Moist, Fractured; Layer
4. 0 : ::'; .. :. of Very Fine Sand ....... '\ ' , ......... .. .. .. .. ..
5 ~~:: :.:' Light Gray with Red .... ".' .. .. .. .. .. -", 6 .. " .. " .......... .. .. .. .. '"
CD · ...... . : 2 ., .... . 7 ..... ~ ..........
,.-... '"0'"
8 .;-.. .. ~ ... .. ... . -,,-
.. ! ',,"-,'
9 : ~~: Bedding Dips 21° S 75° W .
10 : : : :: light Yellow-light Brown,
(;;\ ::.:: : Slightly Moist, Compact
11 ~I:!S~----------::,-----l
.. :: : ::: Bedding Dips 10° N 58° E
.......... 12 •• > .......
.. " .... -. .. ...... .. 1-3 ...... " " .. --' ..... .. .. .. .. ..
.. .. .. /-, ,-...... -....
.. .. ~ '. f' ",
1'5 .:. ' .. , Light Gray, Layer of Very Fine
.: .:'-: ... ;.: to Fine'Sand
!. ••••
CLAYEY VERY
FINE TO FINE
SAND
SLIGHTLY
CLAYEY VERY
FINE
30.8.8.3 100.4 0.46
63.8' 9.4 113.8 3. 11
37.4.' 6.5 108.8 1.86
35.2 : 4.2 108.0 3. 35
Layer of Very Fine Sand 1
Continued on Drawing No.3 o -Indicates undisturbed drive sample
. -
PROJECT' NO.
72 .. 1 .. llA
0-Indicates loose bag sample . ,.
'" -The elevations shown wereobtafned by interpolcitf~n of co"tour
lines on Ric.k Engineering Company Drawing 3915-1, dated 8-20-71.
BENTON ENGINEERING, INC.
DRAWING NO.
2
'.
~. , '
• l
, ~, .. • c8
.2 8 u
" • ' " .":f
•
'.
I,. t'
f
I
!,. ... i
~
•
SUMMARY SHEET
BORING NO. 1 (Cont.)
1'27~ .....
,,; .. ,--'-"
' ...
>: ' " .' .,'
-I'nt.l. ',,',," I ~o-'.. , ,.' .'. ",'
" , " '. r" • ,
, : 29~j':~:'--': ",' : .:
, '. ,'::;,,' ~:' "" ;
, ''In'' ,',' " .' " 'ov" ' •• ,.,;
n·I:At~: : l:~ . ",'
" ,;0. ' r;,'.. • "" " •
Llg,ht Gray''QnQ:~~, Sllghtl¥
Moist '
I)" ,',. f-~"::"~'=J---------~--'----1 ,w.r.-1"-' " ••
>, ,: ;, • , :light Gr9)', MO,', '1st
, ,;. " . " "f:;33l~:": ':">':';' , 'c',,' ,"
, '~_' ',0 ..
,~, ,.:" ":'"
, 'i:, :,' 0
'351;,,'<-\' Brown Wlfh Rekl and Yellow,
SLIGHTLY
CLAYEY VERY
FINE SAND
CLAYEY VERY
FINE SAND
\
44.0 11.31110.2 4.59
99.0 9.21114.7 4.55
" .. 71.5 20.31108.4 3.96 :",,~}~ , MoI$t, FJrm, Highly Fractured,
~ .;1\,1I'\9J With h'9n'Stal~ god GyPJum
SILTY CLAy
~ '1\ 1035 . .5 Feet, 9 by 18 Inch
3"} ,,''iIi C;:ement BoO u Id6·~ aNt C4~tWact, . '~ Contact ips , ' I ,
~ , ,
Green-gray with Red
, , Continued on'Drawina No.4
PROJECT NO. I
72-1 ... 11 A ,BENTON ENGINEERING, INC.
DRAWING NO,
3
•
•
•
•
•
•
•
•
•
... , , 'III
III ... SUMMARY SHEET'·
....... z ... Ao III
C
BORING NO. 1 (Cont.)
38-. :, ':Green-gray WHh Red, Moist,
, . Firm, Fractured, With Iron
: 1.1.:1':1' Sta.ins and Gypsum
41 ®g"1
42
, 43-
44-
,',
. "-',
.' ",. Brown with Reel, Mottled,
,; :" Beddlng Highly Fractured,
N.:arae Amount of GVD5um
Grav-black
, 45-:, ,: Gray
46-@ ':' ',' ± 1 Inch Thick Cemented
47
AS-
49--
50-
mm Layer
, ""',,
Lenses'of Light Gray, Clayey
" ,. VerY Fine to Fine Sand,
Scattered Sea Shens and
, , S,Jjck~sides to 5Q.8 Feet
51@' " ± 1 Inch Lenses of Cemented
52
53
54
,': 1\ FIne Sand
.. ',' ' ± linch Thick Cemented Layer
SilTY CLAY
117.7i 19.5 110.5 3.41
123.2 13.6 ~ 15.2 3.~2
119.7 15.7 118.5 3.43
"
$ ~IL ______________ JL~------~~~~~~-J 56 @~ ,~ 86.9 11.9 h17.9 5.63
-
-
PIlQJECT NO.
72-1-11A BENTON ENGINEERING, INC.
DRAWING NO.
4
•• ! f
•
•
•
•
•
•
•
•
•
J
0 ~
~, e ... c&
.2
S u .s
SUMMARY SHEET
, .-
BORING NO. __ ~ .... ·2___.
ELEVATION _ 85 QJ
·
., ...... : : :: Light Gray and Light Brown
· , . " With White, Moist, Firm, , 1,W ~,~ ~'~' Lenses of Gray Silty Clay
2-.. ,e" ••
to ......
0: ...... ,
3 : : ~ : , Light Red Light Brown and
CD ::: :: Light Gray, Slightly Moist,
4 1 ' , ' . '\~ayer of Very Fine to Fine
: : : : : ,,,,,and ..
5-:: : : ~ Zon'e of Hrghly Fractured
: : : : : Materiar to 19 Feet
6 : L-ightGray With Yellow and
" ., Red brown .. CV'~: ::.:--l
7 ', .. " '
,
9
1().
.... IO" .. .......... ..... .. ~'-· , .-. : : : : : Bedding Dips 15° N 42°, E
.......... ........
.. .. "II ~ -. ..........
'':.'' .. , ...
~ .. ~.. .. ":."
• (";;"\ . l' • •
11 '.Vt:::j:~: ::j: ---'--------~ · ,\", .
· ..•. : Fracture Dip 81~ 5 l~.o W
12
13
14-
15
16 Q
17
·
1~
........ ........
.. '" .... .. .. .. ..
....... ~'
Bedding Horizontal ........ .. .... .. ........
.. 10 "" ........ .. .. .. ..
.. t' ...... .. ~ -...
" .......
, ,I' .
.. .. .. .. $
,: : :, :, Rootlets in Fractures ± 1/4
: : :: Inch Wtd~1 Vertical Fracture
~: :: Strike S 30° W
, .... · ...
' ... -~
CLAYEY VERY
FINE TO FINE
SAND
1.76 11.5 106.0
8.8 6. 5 102.0
8.6 6.4 102.8
19.8 9.0 111.9 4.23
;'~"~'~~~~~~~ __ ~(~~~~~~~jes~)~ ~~~--t--r--t-II~-j 19 ~ . '. ~ , ~
,~ Light Gray With Rei d, Iv\oist, SILTY CLAY~
20 Firm, L1tns.s of C ayey Very ~
t$$. ~$SS~: I~tne Sand
21. @~= Highly Fractured With Rust
Stains
PROJECT NO,
72-1-11 A
Continued on Drawing No.6
BENTON ENGINEERING, INC.
35.2 15.8 104.5 4.36
DRAWING NO.
5
•
•
•
•
... ... ' .. GIl: ~...... fA' ........ CL .... ~.IG :z: •• -c. ... II(:J' 0 ... >-:; "'Z ~ U·~·
SUMMARY SHEET
BORING NO. 2 (Cont.)
.:II
22
23-
-'. Light Gray With Red, NIois~,
, ~. :. :, Fi 1m, lense$ of Clayey Very
· .. ~ -Fine ,Sand., Highly Fractured
. , . " WtthRust Stains
'.. '\
"",-,
.. ~"': (:' 'light Gray Wi.th Red, SI jghtly
: ::~; : Moist, Firm, Contact Dips 6° .. ' .. " .. '. :25 "".;,,' ..
.. :~~ -! ,-•.
,26 ~) ~~_-i~":~,~ . Gray With Red-broWn, Moist,
. ' ' ',~ Firm, Highly Fractured, With
27 ' ' , Iron Stains, Contact Horizontal
. ': :,'" ~rown With Gray-and Red-brown
SILTY CLAY
CLAYEY VERY
FINE SAND
(Merge.s)
• '0 ~
28
, :29
•
•
•
'.
\
,I
Ii. If -:!
I
Ii'
;.
, .
~ " g -f..1, 30 c8 ' , . ,
, . ,
,,<.
, , ~ 31 CU",
u . t$$.I7'~"~· ·-:7":-,:~--:-.....o.--:-1 SILTY CLAY
32 1!liotIotl .... '~ Gray W,i th Red-brown, Lens of
~,
, ... • ~
33-
34
'35
1I1IlI!oiI~ Clayey Very Fine Sand, Large
=~ Amount of Gypsum, Beddi ngs
....... ~ Dip 70° S 00° W.
': 36-Q >: -, Brown Wi th Gray and Red-brown
-
37-
'38-
,. 39GJ
40
,41"0
" .
~ ..
-.. ' ...
.. 01 ..... , .-.• -. ,. .. ...... · . · . · ... ., , ... · . -.. · ...
· . '-.. ' ... , ' .... ·,-·0-
Light Gray With Red-brown,
Slightly Ntoist, Compact SLiGHTL YCLAYEY
VERY FINE TO
FINE SAND
~ 42 Continued on Drawing No.7
PROJECT NO.
72;..1-llA BENTON ENGINEERING" INC.
24.2 18.7 102.8 4.18
51.7 24.0 97.0 -
42.9 19.5102.2 2.59
92.4 7.3 ~ 11.0 6.88
DRAWING NO.
6
I I
•
•
•
•
• .2
8. u . .s
•
'.
•
• III • tC Z
~.
•
SUMMARY . SHEET
BORING NO. -2 (Cont.)
:':"::':_~:' Light Gray with .Red-brown, SLI G HT L Y C LA YEY!-----.,.-1----+----4---------1-'---1
43 ~~.:0!1·1\1,Sli9htIY Moist, Compact
. -: ::: Brown With Gray and Red-
: : : : ;I\brown, N\oi$t, .Firm, Highly .. ~ l \ Frachtrftd With Rust Stains
VERY FINE TO
FINE :SAND
SILTY CLAY
u_ @ -.. ' Slightly Moist Firm VERY FINE TO . It l9ht Brown and Reel LIght Brown, CLAYEY
"1V-~~. I FIN E SAN D
47
48
49
50
·
·
·
·
-
-
.
.
~mJ Green and Gray With Yellow,
~~ Wtoist, Ftrm, Highly Fractured,
. ':. WI th Gypsum
SILTY CLAY
..
'IOJECT NO.
72-1-11A BENTON. ENGINEERING, INC.
JJ-.-.....+.-.,.---I--....j.----,--j---I
I)----!---+--~
/36.3 21.3 105.0
OIAWINGNO.
7
•
•
•
•
•• . '0
~.
!
• .2
~ .s
••
••
•
I •
SUMMARY SHeET
BORING NO •.. ....-..;:;;3 ...... __
ELEVATION 91 • O·
EU ~ ~ ::: Gray-brown, Moist, Loose to
1 . . . .. N\edium Firm, Rootlets,
· .. ~. Sliohtlv Mi tIC:' · . 2 ..: :: Light Grpy and LIght Brown
. m.:::~·: With Rust Spots, Slightly N\oist,
3 : : : :: :' ·F.irm, Slightly Micaceous ........... -fj\::' ..
4-\..V : : : : .:
5 W ~ ~ ...
.. "" ...... .. -. ~-:. .. 6 .......... ... . ~'.. .. .. ..
7 r:iI :: ... t.=!.J .. . CV .... .
8 2 ::: .. .
," 'If. ~ .. .. .......... . .. ........
9 .. .. .. .. .. .. -....... .. .. .. .. .. · . , .10" .' ...... ' ... .......... .. ........
.. .. .. ~ -.
... .. .. " ....
Light Red Light Brown With Gray
Interbedded Layers of LIght
Red-brown Clayey Very Fine to
Fine Sand
Light Yellow-Light Brown With
Gray and Brown and Red-brown
Light Gray and Yellow
CLAYEY VERY
. FINE TO FINE
SAND
CLAYEY VERY
FINE SAND
SILTY CLAY
CLAYEY VERY
FINE SAND
Continued on Drawing No.9
PROJECT NO.
72-1-11A BENTON ENGINEERING, INC.
17.6 4.1 ~03.2 1.35
22.0 10.0 ~01.1 1.80
33.022 .• 2. 97.1 . 2.6:
26.4 13.8 99.4 4.09
DRAWING NO.
8
------......... ---------._...,..----.,.-"------/....,...' -------~~--~-~" =,-~,-,~, =,--~~--~,--, --,
•
:.
•
'. g
-<
• i
.2 ~
~
•
•
•
• III ~ ·z
~
.... III ' ••. III ... III •
!!:' 'A. III ---'C .. 'III .. = ~; O~~ ~"" Zlll U III
SUMMARY SHEET
BORING NO. 3 (Cont.)
4=11
.:~: ,:: Light Gray With Light Brown and CLAYEY VE'RY
21 ' '. ' Red-brown, Slightly Ntoist, Firm, FI NE SAND . [I] . ': '. 1\ Slightly Micaceous, Lenses of I
22' "'-I \Gray I MQist SI I ty Clay .
-, ~. C;;;ray-brown With Yellow ·and
23-',:_ ':-: ,':Brown, Ntoist,Ftrm, With
, ,: .. Gypsum Seams and Rust Stained
24-0 ~. ,_: ,'~ -Fractu.~, Contact Dips l()O 26.4 27.2 94.5 2.48
'. S 200W,
25
26;
-~ -,' -"
", >-'.. • '. 27~
-, .' -,,"~
SILTY CLAY
39.6 23.,4 ~Ol.0 3.72 ·2~::.Ci) : :.'. :. '.
'.29;:[§]J$·:_$::.:~:=;,lL....,...i9..!..<h,..;-t-G-ra-y-,W~ith-.. -Ye-I-Io-w-a--'n--d-~--"------l--+--+-+-+~
,.' ... :: _: Red-brown, Slightly Ntoist,
.' 30 ;.; ~ .. Slightl'y Mic~ceous, Contact
~: :: :: Dips 2° S 72f? E
, • -e::. io'. . • .31" ...
'. '_ .• !-.
32 G:) .~~ ~i,~:~,~ Lenses of .Gray"SfltyClay " . ~ II'·.,' ••• ", 1;::; •. ~~ ;::':. . :t-:-:-:--:-~~. 7:' '''-:---:----:-:-____ -1 ,~., ::3a:.· .:,': .:.:::: ;. Li~~t Broytl'f brtd Red-Light Brown, [1J ::' ::::: Layer of Very Fine to F~ne Sand
34. " ... :: "
".: " ~ ... .
'-, '35 . :: ~ ; : Brown, Larg!l Arno~.mt of , ~' ... ·,1\ ·Gvosum SeamS:'. " .
:,: .'3(1:.CD ~'~::~ '~~ Light Gra~ with, '~-btown
" ;:~ :.':.: Lenses of Gray,'Sihy Clay
,37-. 'l~: '.~-1 1/2 Inches Th1ck
.38, : -:. ' G~y-g.-ay \yith, Red-brown,
11:0·1 ., : " MoUlt, Firm, Gypsum Seams
3n ' '.' .: and lro~ StainSi"Contact .Dlps
:' ~7 , , 220 S 200 W
40 @ ,,',',' ,
__ ,1
CLAYEY VERY
FINE SAND
SILTY CLAY
Contlnu~ Qn Drawing No. 10
, PROJECT NO.
72-1 ... 11A BENTON·" ENGINEE'RING, INC.
74.8 18.0 110.2 5.00
41.8 12 .2110~9 6~47
63.E 18.8 109.8 2.92
DRAWING NO.
9
••
•
•
•
•
\ ' ,
•
' •. oS
•
••
•
.'
t-.. -SUMMARY SHEEr 'III III ;.Alii '" . ... A.-"-.... "' .. ~ (Cgnt.) z -~ !"'C~ BORING NO., t-~!:) 0 .... >-~z A. III a
42
43
"'U'"
'. Green-gray With Red .. brown,
MQ,ist, Flrm, Gyp$um Seams and
IrQn Stain.
44-GJ)' ~:
45
'Blue-gray, L.nses 'of Sandy
47 Clay and Light G~y Clayey
Very Ftl1e' Sand 4S@. "
49
50
55
56
57
5S@:'
.
-
Inter~dded Ce.mented Layer
18 Inches Thick
Interbedded, Cemented Layers
". '. ± 1 Inch Thick'
.'
SILTY CLAY
PROJECT NO,
12-1-11A BENTON ENGINEERING, INC.
)..
(!) t;:' '" ~ ~ t;:' '" J.: m ' .::.. in' . U I&. Z ;;;-a::t ~ Z :) • Z !, ,
'" ......... )0 '" U ceO -"''''. a __ "'t-v. '" ~. - --::-:c'''' ..... > ..: ",oa >-:a "'V;f ' .... ~~..... "'-a . 0 .~
31.9 1'S.2 ~ 10.9 -
59.4 14.9 115 .. 0 '3.75 .
91. S 18.2 112.9 3.99
170&5 17.3 112 1
DRAWING ""0,
10
•
•
•
•
•
•
.,
•
•
•
•
11.1
=-c ~
ID o '.,
QlJ
. .
.' . o ' I
n-
1
"
2 . ' ..
" .
., ., . ' . ,11.1 z O(~ ..
~
2 :z: ... H 11.1 .... IlL. =-c 2 II)
" . ,
II. . " , 0
+3 ... z 11.1 C,,) g: 11.1+2 IlL.
~+l
-4 ------tc 0 :;
0 0 II) ~ t> ! C,,)
1
2
PROJECT NO,
72-1-llA
CONSOLIDATION CURVES
LOAD IN KIPS PER SQUARE FOOT
0.4 0.6 0~8 1.0 2 ,4 6 8 10 16
: ': t . , · . . . . · .' . . ' . .' Boring No. 1 . . · · . , . .' ~ " . " .. . . . . · . Jklg No. 1 . . · ~ , . . , " .. '.
" .Depth: 181-191
Remolded to 900k of
\ Maximum Dry Density 1"'-_
1-_ -, IJ..
t----r--, h --r--r---......
1"""""
" . ... . . .' . ~ . " . .' . . . '. ., . . . " " . ., . · " '. 0.,' " .' . . . '. , , , " .' . . :" .' , . .
. . . ' . .' . · " " " I; • Boring No.1 . ' . .' . • , .' . .~ . .' Bdg No • 3 ; . '. .' , " . . . '. .' Depth: 39-40' , . .
Remolded to 90010 of . Maximum Dry Density
""1 il-
-~ h f-....... -r--'-....... ..,. . .' . ., .
.·0·"' . " . .
I . · " , , . " .' . .' . " . ': . . '. . ,
Boring No • 3
Bag No. 8 r-----. .. ,Depth: 29-30'
' ,...""" ........ Remolded to 90010 of '1 ~ Maximum Dry Density
~ 1---... ~ t---1---l-t--"" ~ r----. ' ~ '--1---_ . --, . , -1--_ ...... ~' t--~t
,~
0 INorCATES PERCENT CONSOLIDATION AT FIELD NOISTUR,E
• INDICATES PERCENTCONSO LIDATION AFTER SATURATION
DRAWING NO.
BENTON ENGINEERING, INC. 11
. -, .
• CONSOLIDATION CURVES
LOAD IN KIPS PER SQUARE FOOT
•
•
•
,. .-.
•
+lp2 0.4 0.6 0.8 1.0 .2 4 6 8 10 16 .. Boring 3 --r---B'ag No.5
+10 r-....' Depth 13-14'
.~ ~ Remolded to 90%
r--... of Maximum
+9 ~ Dr" Den~;it..,
i) ~ +8 \ +7 \ ., .,
11.1 ~6 I~ 2~
:z: ...
+5
11.1 \ ..J Q.
:II :r4 \ .... ,.
0 ~
~ t: ~ • 0 . .... , s u
0 ...... '. ,
•
0 1\ +3 ... \ z
11.1 u ':51-2
Q. \.
~1 1\
~ \ e, ~ ~ ~ 0 .,' ,r----. ........ ! ( ~ ~ ~ u r--..... :1 1--'
....... r--.. \ i"-~~
"2 ~ '. ...... \ r---~
·.3 I-----.. \ ...... r-...... ~, i'-
:4
• III :II C ~ 0 INDICATES PERCENT CONSOl.lDATION AT FIELD MOISTURE
• 0 • INDICAtES PERCENT CONSOLIDATION AFTER SATURATION ., ,
• PROJECT NO. DRAWING NO.
72-1-11A BENTON ENGINEERING, INC. 12
-
• CONSOLIDATION CURVES
LOAD IN KIPS PElt iQUAITE FOOT •
•
•
•
•
+1 'R2 0.4 0.6 0.8 1.0 2 .4 6 " .8 . _.10 16
. -.. SoHng 3 . r--~ Bag No. 10
+10 ~ . Depth 38-39'
.......... " . Retno Ided to 90 % .. '. ;'1
"'-of Maximum
+9 Dr Den:,itv
I') ~ +8 \ +7 \ ., > • .,
iii z+ 6 ~ , \ ~
% ...
+5
iii \ ...J 0. 2 ~+ 4 \ l&. 0
+3 ... \
·0
! « • ~ g
c&
0' .... lit 0 U
0 • -'
•
z 1\ iii (,)
ffi+ 2 0. \ ~+ 1-l .
ij ~ ~.
0 "' ........ 1\ :::; s-:-0c ~ .......... r---....... \ ! r-.... (,) i"-1 t-....
ro ... ~" \ ,2 ........ ~ ........... ~ r-.......... :3 ....... " ...... " ~. ". ;·4 1 . '
I-.... a -: 5
c z 0 INDICATES PERCENT CONS01.IDATION AT FIELD f!lOISTURE ..
0 • INDICATES PERCENT CONSOLIDATION AFTER SATURATION ., i. PRO".EC,:r NO. . . BENTON
DRAWING NO.
72-1-11A ENGINEERING. INC. 13
•
•
•
•
•
•
•
I I.
•
BENTON ENGINEERING. INC.
APPLIED SOIL MECHANICS -FOUNDATIONS
6717 CONVOY COURT
SAN DIEGO, CALIFORNIA 92111
,PHILIP HENKING BENTON
",UE.,DIENT • CIVIL ENGINEER
APPENDIX A
TELEPHONE (714) 156!!-1915!!'
Unified Soil Classification Chart*
, SOil DESCRIPTION GROUP
I. COARSE GRAINED, More than half of
material is larger than No. 200 sieve
size. **
GRAVELS
More than half of
coarse fraction is
larger than No. 4
CLEAN GRAVELS
sieve size but smaller GRAVELS WITH FINES
than 3 inches (Appreciable amount
of fines)
SANDS C LEAN SANDS
, , More than half of
coarse fraction is
, smaller than No.4
sieve size SANDS WITH FINES
(Appreciable amount
of fines)
II. FINE GRAINED, More than half of
material is smaller than No. 200
sieve size.** SilTS AND CLAYS
liquid limit
less than 50
SILTS AND CLAYS
liquid limit
Greater than 50
HIGHLY ORGANIC SOILS
SYMBOL
GW
GP
GM
GC
SW
SP
SM
SC
Ml
CL
OL
MH
CH
OH
PT
TYPICAL
NAMES
Well graded' gravels, gravel-sand mixtures,
little or no fines. '
Poorly graded gravels, gravel-sand
mixtures, .little or no 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 sands,
little or no fines.
Silty sands, poorly graded sand-silt
mixtures.
:Clayey sands, poorly graded sand-clay
mixtures.
InorganiC silts and very fine sands, rock
flour, sandy silt or clayey-silt-sand
mixtures with sl ight pla~ticity.
Inorganic clays of low to medium plas-
ticity, gravel'ly clays, sandy clays,
silty c lays, lean clays.
Organic silts and organic si.lty-clays of
low plasticity. ,
Inorganic silts, micaceous or diatomaceous
fine sandy or silty soils, elastic silts.
Inorganic clays of high plasticity, fat
clays.
Organic clays of medium to high ','
plasticity
Peat and other highly organiC soils.
,Adopted by the Corps of Engineers and Bureau of Reclamation in January, 1952.
* ,All sieve sizes on this chart are U. S. Standard. ,
.... -------------------------------------~-----~--~-
•
•
•
•
•
•
•
•
•
•
PHILIP HENKING BENTON
.. /lEal DENT • CIVIL ENGINEER
Sampling
BENTON ENGINEERING. INC.
APPLIED SOIL MECHANICS -FOUNDATIONS
6717 CONVOY COURT
SAN DIEGO, CALIFORNIA 92111
TELEPHONE (714) 565·191515 .
APPENDIX B
The undisturbed soil samples are obtained by forcing a special sampling tube into the
undisturbed soils at the bottom of the boring, at frequent intervals below the ground surface.
'The sampling tube consists of a steel barrel 3.0 inches outside diameter, with a special cutting'
tip on one end and a double ball valve on the other, and with a lining of twelve thin brass
rings, each one inch long by 2.42 inches inside diameter. The sampler, connected to a twelve
inch long waste barrel, is either pushed or driven approximately 18 inches into the soil and a
six inch section of the center portion of the sample is taken for laboratory tests, the soil being
stili confined in the brass rings, after extraction from the sampler tube. The samples are taken
to the laboratory in close fitting waterproof containers in order to retain the fie·ld'.moisture until
completion of the tests. The driving energy is calculated as the average energy in foot-kips
required to force the sampling tube through one foot of soil at the depth at which the sample is
obtained.
Shear Tests
The shear tests are run using a direct shear machine of the strain control type. in which'
the rate of deformation is approximately 0.05 inch per minute. The machine 'is so designed that
the tests are mad~ without removing the samples from the brass liner rings in which they are
secured. Each sample is sheared under a normal load equivalent to the weight of the soil above
the point of sampl ing. In some instances, samples are sheared under various normal loads in
order to obtain the internal angle of friction and cohesion .• Where considered necessary, samples
are saturated and drained before shearing in order to simulate extreme field moist~re conditions.
Consolidation Tests
The apparatus used for the consolidation tests is de.signed to. receive one of the one inch
high rings of soil as it comes from the field. Loads are applied in' several increments to the upper
surface of the test specimen and the resulting deformations are recorded at selected time intervals
for each Increment. Generally, each increment of load is maintained on the sample until the rate
of deformation is equal to or less than 1/10000 inch per hour. Porous stones are placed in contact
wrth the top and bottom of each specimen to permit the ready addition or release of water.
Expansion Tests
One inch high samples confined in the brass rings are permitted to'air dry at 1050 F for
at least 48 hours prior to placing into the expansion apparatus. A unit load of -sao pounds per
·square foot is then applied to the upper porous stone in contact with the top of each ·sample·. Water
. is permitted to contact both the top and bottom of each sample through porous stones. Continu~us ..
observations are made until downward movement stops. The dial reading is recorded .and expansion'
is recorded until the rate of upward movement is less tha~ ]/10000 inch·per.hour. . .