HomeMy WebLinkAboutCT 73-45; Loma Laguna II; Soils Report; 1973-01-02WILLIAM S. KROOSKOS ii ASSOCIATES
Vr. ii’. Al lan Kelly .Tob 140. 73-4s ne
Rancho Agua Hedionca
;,,~ P.O. Eox 463 a,.. bG>' Carlsbad, California 92nr\E Cr 7,345- I.
5, SUBJECT : Report of Soil Investigation 17, .!,A .: 1 $ Lorna Laguna II ii,, East of Park Drive g; Carlsbad, California
2, ;::< Dear Xi-. Kelly:
:' In accordance with your request our firm has performed a soil ; investigation of the subject property located immediately east of
:_~' the eastern terminus of Park Drive, ant: scuth of El Caminn Xeal in
$c the City of Carlsbad, California.
? [~j The soil investigation consisted of advancing several boring
F excavations at random locations on the subdivision site in order :; 1 to visiially classify the underlying bearing soils and to obtain @$t:: typical samples to be tested in t~he laboratory. Laboratory tests
ii%& were performed on these soils in order to determine their physical FT,?
it, :: and s!iec!ianical characteristics.
@>:The enclosed report sii;rs2rizes the result.5 of the soil investigation
and includes our findings arJd recommendations. The enclosed 8.recoaxlendations for the proper de17elopment of the site to receive
$;:the one and two stoq, structures and other improvements were nade
p,with t?,e intent to satisfy @the governing agencies. t‘ne soil invrstigation requirencnts of
c&x;; :;$$
phe predominant natural ground bearing soils on this site consist of @ayey silts and sands. A small amount of unconpacted fill exists ;m ~the northwest ccrncr of the prcperty.
popsoils consist of
In addition, the underlying
brown sandy clays which possess expansive
;$aracteristics. It is our opinion, if the recoxnendations suxmari7e
3 this report are followed for the proper treatment of these @compacted and expansive soils, the proposed structures will be
safely founded on these prepared soils and will not suffer detrir,enta
I"age. jl, ., 2.
$is opportunity to be of service is sincerely appreciated.
Very truly yours,
i:I iL IA!? S . K~oosKos & ASSOCI.?.TES
l.;i?li~am S. Krooskos, President-
RCE 11318
d
1
?ac;p 2
1 Investigatic~n Jrl-, !i@. 73-2108
prr;lu,q:cd cuts on the site k:ill be a maxi:num of 30 feet !<:ith sut 'IT,',- "f 2 r: i *:i p t ir. Ileisht. 'OBSCL5.= mai:'. 2";' Feet ir?'~.:;ei"ht. !4axir,un fill slopes will be
~f.4”cxlmate~Y ,*~mt~or fili.
Most pro,r!osed lots will I'? Fnt~irel;; Ap;.roxinatcly 29 oi the Cl prc2psed lots will
-rain da);liqhi ?Sri-;iS. ,A11 slopes, accordix; to the Tentati'Je '.:a;;,
:, kf,fJ be constructe2 at inclinations of 2.n l:orizontal to 1.n vertjcal.
,~~,~.~(~Tz'~C')NDITIO~~:$ :
"!T!i'gils +n!~the site consist of j~nterheddc,d clayey sand, cla.vev silt,
,,,:>;kSi'x~y sandy clay an:! silty sands. The clayey sar.ds and silts p 0 .Y s e s 5 $p&&un-expansive Char,3cteristics, while the Clays, W]>iCh cor);:risp
,+jc~ &ly~ a:small percent of total xaterials to i)e riovf*, ,;':hj+ expanSiVe cjlaracteristics. Daylicfit
possess 3ec?iur: to
areas will expose ion-
.jI:&ansive to highly expansive topsoil materials and will have to be
~,, jnspccted during grading operations. ,-,,p 15~,foot thick bed of IIoYing Iju;.bers 7 throuch Q dcf~ine
'-~rhterial. b:cll (iradcd sane !:.!iich can he used as car);.inry The a:lpro;:ix;rie ?irjts oi ti:C: sand hed are showr! or, Figure !jo. I. 'i'i..e C:C:pth of 100s~ alluv:' UE in the canyon bottom rar.qes
from t;;o to iive fr-et. ,,, ,.,,
FTELD IWESTIGA'IO.ZS:
k total of 12 bGri!!qcs xere &~~ivar:ccc! on the site. vcrc located in the ?heir positions
ficl? by our enqineerinq qfolcgist rcicrri!;q t-r "a '?entativc Xap of Carlshai! 'Tract Xc. 73-45, Loma Lac:ur.a 11, pre!,arcd
by Rick Enginccri~r:q Co:rpany.
“~“The test hor.i nqs V:CTP asvanccd on D~ccrbbr 17, and Dece~hcr 14, 1073, by our track no\;ntcc'. ail<:r:r drill workir,n
~,Our eqirecril;g qeolo$ist. under the supervision 0'
~.,~."'?$T~c encountered soi 1s
~'.?::'~identifiec! *"rink were examined continuously and visually
,,,, the CiL?ld cpcraticn i:y our enaineering ceoloaist.
~;~Test Earing Logs were prepared on the basis of an inspection of t!;e -:~.~~~,?~borinqs and t!le results obtained are sunmarized on the attached fiq-res.
i-;!S.~,:lUndisturbed core samples were obtained of the natural qrcuxd OX,; ;':?uSinq d two inch diameter "split tube sarpler" . soils The sampler is drivfr: .lntO the soil uti1izir.q a 30 inch droD of a 14f1 pound hammer. A TfCG.‘c! :,;~i~:of the blow cour?t is made and after the sarpler is removed from the
.,.:,,. :~.?round the brass rinos containinq the sampled soi'ls are sealed iz I~>, air ,+:?tight plastic containers and transported to the laboratory for testinq. ??%The aforementioned rr.ethod of sappier penetration is known-as '+".;stdndard Fenptratioc Test the
...'~:i!%The nomenclature i;sed in tiescribing the soils is outlined in acccrdacce with the Unified soii~ Classification System as illustrated or t:rc
.; attached chart ir, the rear oi this re;xort. ;:., A.l-l::'cSOil densitit:: crrc sj-ver: zs .;cry :oosc ~~.E;.*..: very dense , loose for silts a-d sands ;:ith , medi.u:i dcnsc, cZcr~i‘f, or
co;bbles; and as harti, :-i-n a.rd '~~.;p:w 'j ,,Z..~..< i;; 5:::
* +Q.,., , <~,:<,:T: REPCRT Ci‘ c‘ OiL '[:iVi.CTIGA'~iO:J
i.iXQ LAGi;:Jn i I
ias5’ o!‘ “ARFC i)Rl’.‘I:
.., CARL.SI-:dI"iD , CAL T!W!?:: IA
e: ’ ,~ . yhps ,report presents t!-.c findil:gs and results of our scil investigation ,at tj>~ site of the prO;iosed sJ!xiivision and other contemplated
,,~~~pzovencnts . It is our understandinc that the site is being ir!provcd
'yule& ypaacive approxinatel:: 61 sii:;qlc> fani];, dvellinqs a naximur;: of two ~~ g*ries in heig!~:t, t0 i::e Constructed of conventional type foundatior,s, spread $ootings, and nF Standar-d t;lpe building materials.
~?;;nth the ~above in rii;i , this soil investigation was undertaken in
j ;; :~j+3e' :+o :
,,$.~;I~;~ tlaassify the undnrlyi::(~: soils and depths to the various stratas :,i ., from existing top of grcund.
,';~2; Determine the allo~wahlc coil hearing pressures for the natural ground and these sar:c ~,;lttrials used in the co;!pacted fill, based on analvsis <.f s!:car and consolidation tests of the encountered underlying soils.
3. Detemine th!: :,ri;sencc and effect of any expansive soils and tHYCompacted fill soils that would cause detrimental damage to
proposed Structures and other appurtenances.
4. Predict the si~ttlczent oi the natural. ground and compacted fill of tlie same mtc-7~ ial under the proposed structural loads.
5. Recorwnend trca+xcnt for areas containing expansive soils and mcompactcd f i 11 soi 1:;.
'+:6. .Determine ', any construction prohler!s that --of the soil characteristics encountered. nay develop as a result
'~',_
,&I ;<:: ~~'~..~~~~;~+ ,i
'..,?k+%ite; consisting of 21.72 + acres, Ehe existing Lona Laguna I subZivision, is located immediately east of east and south of ~1 Car.ino Real. of the Park Drive terminus
~+JPerty is bounded on in the City of Carlsbad, California. The
the southern edge by hillsides sloping down to
.the. upper flats of ~gua kiedionda Lagoon.
~-,,The'property is Situated on southerly draining hills rising frorr, 10 to +o feet in eler1atjon. Veqetaticn consists, of noderatc. grass and low ,kkush covering roost of the Site.
the site. At present no structures exist on A 14 inc!: xater ‘main which will be abandcned parall.els the northwestern prcprt:- lint. %feet i An existing cut slope ranging frorl !i to n height pa!:al:ils t!tti western during the gratiirq property line and was CoInStruCted for Lcxta Laguna 1. &ring the grading ror Loza ~aguna II. T!iiS slope will be elininated
.,~',Z
UNIFIED SOIL CLASSIFICATION CHART
SOIL DESCRIPTIOK GROUP SYiYBOL TYPICAL NAMES ,',
COARSE GRAINED Kore than I~ '., au. .ri half of material iS larger
., -: " than a No. 200 sieve. ,. ,,:.:;;;:; GRAVELS CLEAN GRAVELS
More than half of Coarse
fraction is larger than
NO. 4 sieve size but ,':>jlY
GIL’
GP
smaller than 3".
*,,s ., GRAVELS &ITH FINES
,JAppreciable amount)
GH
$'J ,, GC
sz; ';‘ ;: ( ;, @:;.sA*Ds CLEAX SANDS ':, :-More than half of coarse ,, fraction is smaller than
4 sieve SANDS WITH FINES eciable amount)
SW
SP
SN
SC
FINE GRAINED More than
Well graded gravels, gravel and sand mixtures, little or no fines.
Poorly graded gravels, gravel and 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 sanc?s, gravelly
sands, little or no fines.
Silty sands, poorly graded
sand and silty mixtures.
Clayey sands, poorly graded sand and clay mixtures.
half of material is
smaller than a No. 200
SILTS AND CLAYS sieve.
::, ,,I ,,
a-,:.:..* Li uid Limit :'F$.,;:r .~I IeZs than 5o -
CL
OL
MH
quid Limit
qreater than 50 -
Inorganic silts and very
fine sands, rock flour, sandy silt or clayey-silt sand mixtures with slight
plasticity.
Inorganic clays of lot to
Medium plasticity, gravelly
clays, sandy clays, silty
clays, lean clays.
Organic silts and organic
silty clays of 10~:
plasticity.
Inoroanic silts, micaceous
or diatomaceous fine sandy
or silty soils, elastic
silts.
Cli
OH
"T
Inorganic clays of high plasticity, fat clays. Organic clays of mecium to
high plasticity.
Peat and other highly organic scils.
WILLIAM S. KROOSKOS & hSSOCITiT:S
Soil and Foundations Engineers
Attachment 1
Page 1
GRADING SPECIFICATIONS
GENE.RAL: The intent of this item is to for: properly establish procedures clearing, compacting natural ground, preparing areas to be filled, and placing and compacting fill.material to the grades and slopes as shown on the approxzed plans. \
CLEARING: All vegetation, brush and debris shall be removed, piled and burned or otherwise disposed of to give the surface a neat and finished appearance.
COW'ACTING EATURAL GROUND: After clearing, the natural ground shall
be scarified to a depth of at least 12 inches, watered to optimum
requirements and compacted to not less than 90 percent of maximum dry density, according to A.S.T.M. Test Method D 1557 in,a four inch dia-
meter cylindrical mold of 1/30th cubic foot volume. Field density tests
shall be taken in the natural ground in accordance with A.S.T.M. Test Method'D 1556.
FILL MATERIALS: Materials for the fill shall be approved by the soils engineer and shall be free from vegetable matter and other deleterious
Substances. In the event that expansive materials are encountered
within two feet of finish grade they shall be either entirely removed or thorouohly mixed them in fills. with good granular material before incorporating
No foctinq shail be allowed to bear on soils which in the opinion of the soils enqineer are detrimentally expansive, unless designed for this cla'<ey condition.
,PLACING AND COWACTING FILL MATERIAL: After preparing the areas to
be filled, the fill materials shall be placed in layers not to exceed
six inches in compacted thickness. Each layer shall be watered to
optimum requirements and compacted to not less than 90 percent of maximum dry density in accordance with A.S.T.M. Test Method D 1557.
Compaction of the fill shall then proceed in the specified manner
to the qrades as shown on the approved plans.
Khen the slope ratio of the oricinal ground is steeper than five hor- izontal to one vertical, the oriqinal ground shall be steeped or benched. Ground slopes flatter than five horizontal to one vertical
shall be benched when considered necessary by the Soils Engineer. Fill slopes shall be compacted by means of sheepsfoot roller or other suitable equipment. Slope compaction shall be continued until the
slopes are stable, but not too dense for plantinq.
Field density tests shall be taken when cons,idered necessary by the
soils engineer in accordance with A.S.T.M. Test Method D 1556 and shall
be made not exceeding two feet in vertical heiqht, providing each layer is tested.
SUPERVISION: Continuous supervision of the fill shall be made by the representative of :;'illiam S. Xrooskos & Associates during the
grading operation so that he can certify that the fill was placed
in accordance with these specifications.
& ;,
‘k.!:.i Previouslv snecjfj eo.
SEASON LIXITS: NO fill material shall be placed, spread or rolled durin
unfavorable weather conditions. When the work is interrupted by heavy
rain, the filling operation shall not be resumed until field tests
indicate that the moisture content -and density of the fill are as
Page 3
:;;, ,,;,~ ,,.,~r ;: ~_i
f$f.
.:;i
~~,~~~~!~~
‘.G ,c., _ ->I
'., Mechanical Analvsis: A mechanical analysis was performed on each soil type to determine the percentage of grain size.
according to A.S.T.M. 422-54T. The analysis was A Unified Soil Classification ,Triangular Chart was then utilized to classify the soils.
,,, ~~
Swell Tests: To predict potential soil swell, the clay samples (contained in the brass rings previously described) were properly Prepared and were allowed to air dry for at least two to three days. They were then placed in the consolidometers under a normal load Of one Fsi. Water was then added allowinrl the samples to become saturated and swell. Dial'readings were performed at the start and during,the progress of the expansion test until the readings were
less than 0.0001 inch per hour. These test results are noted on the enclosed Figures.
DkeCt Shear Tests on Remolded Samples: Direct shear tests perfOXed on remolded samples of the natural ground soils. These tests were
,.. &.+rt of Soil.Inx.estiqztion
t-~-Laguna 11
,East,if P~ark Driver
carlshad, California
~Joh No. 73-dir.:
$oft for clays. Soil moistures 'are dcscrik,ed from a range of dry,
&mtp, moist, wet or saturated.
LABQRATORY TESTS:
&oratory tests were performed on the encountered soils to aid in t&&rsclassification 2s well as to determine their physical and ,*ha,pical+~characteristics. ,,&jg r,+ z: >>g$
Th+&;eJcpected~soils to be used in the structural fills, as well as the &i+sed~cut soils, were all tested to determine their suitability for
supporting the proposed dwellings and other appurtenances. The soils
were tested with respect to potential expansivity, maximum drv density aG56ptim'um moisture 'content. Direct shear tests were performed on
r&noldedsamples of the proposed fill materials. Consolidation tests
tiere:performed where possible on undisturbed samples of the natural ground.soils to determine the settlement under varying normal loads.
;,~;:,~
The,swelling potential of the existing clay soils was determined by lbaded swell tests on recompacted samples. As noted in t!:e rear of this report some of the encountered soils do have potential swell.
Swell Classifications are as follows:
Swell Expansivity
0 to 2 Percent Considered Non-Expansive
2 to 6 Percent Medium
6 to 10 Percent ; ,:.a+;,~,, (_;::: ,,_, . . . ,‘, , ._ ,. ;,,y<,“. .,b ,~ ." Above 10 Percent
.,::~ITEST,PROCEDURES: ;;;~~;~~~* ++ ~::,, : -, ,~ 1
!!igh
Critical
Page 4
Job :10. 73-41n1: .~ _! .~\’ :_
Rc$SOXt Of'Soil Investigation
~-a Laguna 11 ;.,$&t of: Park Drive
.:;'T:!~&xlsbad, California ~.~ ~.
":
~xfoxmed in order to dcterminc the strenqths and supportinc
&qpacities Of these existing natural (;round soils compacted to at
~least go percent of masimum dry density. me s!?ear tests k:i‘rc r.ndc
with a direct shear machine of the constant strain type. ?!1e rate-!
,~-of;,strain was apprcqiT?atCly Il.Onl inches per minute. The shear
,~_:.+&jne~ is so desic: *:d that the tests are performed without rer,cvin::
i::;;w&~: specimens from 1:if rincs in which they were remolded insurini: 'iY;a;~&in&um of sample disturbance. Drainago was permitted to porous
,, .&&ones ,above and below: the one inch high sample. The samples are
.' .~~~~~~~~:~~heared.under,varicus normal loads in order to obtain the anqle of
the amount of cohesion.
':~~,:'Consolidation Tests on Undisturbed Samples: Consolidation tests
%Lvcre performed to analvze the deformation of the sampled soi~ls ' ,~subjected to increased loads. The consolidometers like the direct
:sheax,,machine are desicned to receive the speciments in thr rinqs as
2 sampled, thus insuring a nini.-um of sample disturbance. Porous
stones placed at the top and bottom of each specimen, permit the
free flow of water into or fron the sample durinq the test.
nfter the specimen has been piJceG in the consolidomcter and allo~e< fo become complctel;. saturated, successive load increments to the
upper surface of thra soil specimen V;CTE applied and the resultinr: deformations were recorded at selected tir,e intervals, frr eaclh
increment of loadin?. The loading increment is naintained on th<~. test specimen until the rate of defornation is relatively const(ant >. ,and .less than O.Onnl inch per hour.
" ~'Compaction Tests: l'he laboratory compact~inn tests were :,criormcd in
accordance with A.S.T .P!. Test ?lethod D 1557 (tour inch meld, five
~,cE,-.. +v= I 25 blows each layer, 10 ~>our-,d hammer, 1F: inch drc? using: all .,-_~~l"~~,material passing' a :io. 4 si.cve) .
,:,.;,,
" ,$.:;The maximum densitv re-,resents the value to Which it is pcssiblc
.,&<~,t+oompact the soil in the field r,:ith the proper compactive effort. ~:'.: ~~&~.~&::,;': , ~
~,:ii%ri ~place densit\. and moisture content as well as shearinq resistance '.Z I --,,t@st results are noted on the Boring Loqs. Fill suitability tests ::_:~oonsisting ~0f maximum dry density, grain size analysis, direct shear
':~::~-:!-analYsis are noted in the enclosed Fiqures in the rear of tl?is report. "~:. .,“,',c?; :~
‘1’, ,X+SoIL BEARING “AL”E :
-+., :,
:,, ":;'?Results of direct shear tests on samples of :, ~:., the encountered bearin? :+SoilS .~ . indicate good shear resistance and cohesion properties whit'!
,: 1s a measure of good bearing support. of 28 degrees for the angle of Utilizlng the averac;e valur, ,' internal friction and Inn pounds :c:- sguaxe foot cohesion with the appropriate Terzaqhi Dquatirn, the n:aYiZ-;1~ '., allowable soil bearing value of these encountered zatural qrounci sr:i.ls ', and compacted fill soils O: tiese same materials is at least 2,Pcli ~, e,Pounus per square foot.
., ,. .: _, :1 II, ,:~,j.~l .,. a.
:;:.. ,’ ,, $
L ‘, .::,_, j..::,: .,
Page 5
i.So.il Investigation job No. 75-4109
.‘,: ,,$w&;;i;~ing factor to the ahove allow;ible soil hearinq value to hc;
'utilized in the desir;n of footitigs and ioundations of the proposed
Otrucc,ures is the consolidation o f these underlying beari:?o soils
'. ruder the StrUCtUral loads.
u; ., : +~nsOlidation test results of the undisturbed samples indicate that
:+earing soils will settle up to a maximum o f one-half inch under
eign rload Of 2,000 pounds per square foot.
urn allowable soil bearing value of the imported fill
,-(if,used) will be determined at the time of the fill
,~and when an approved borrow pit has been selected.
,,,~ @ *. r-, ;; ,:?$+ ""; d', --I,:""Phe-,following summarized findinqs and recommendations are based on .I~‘-, ',! '~ i' .+he:analysis. of all the data and information obtained from our soil : Znvestigation conducted on this si~te. ,* This includes our visualv ~ '(inspections of the site; field investiqations including the boring excavations advanced throughout this site; laboratory tests on 2xOil samples analysed, and our general knowledqe and experience with the encountered soil types.
1. The predominant bearing soils encountered durinq the investic:ation
consist of clayey silts and sands. 'These soils possess medium expansive characteristics and therc'orc possess : VC to six percent swell as measured by t!le .;fcr.-r.cntic ncd Test for
Expansive Soils.
Exposed at the surface and just belo!: are brcwn sandy clay soils
which possess medium to high expansive characteristics with
swells varyinq from three to ten percent as measured bv the
,aforemen~tioned Expansion 'Test.
A portion of the site underlying Via Hinton Street and several
:adjacent lots consist of compressible alluvial soils from twc
~t0 :fiVe feet in depth. It is our recommendation that these soils be excavated beneath the roa d fill and buildinq areas to a depth Of five feet below the existing ground grade, or to a depth
where firm soils are encountered as approved by the fieid soil
technician. The bottom of the excavation shall then be scarified
:tO a depth of 18 inches, watered to optimum moisture content, ,and.compacted to 90 percent of maximum dry density. All trash and Other debris shall be segregated fron the excavated fill soils
and,hauled from the site. The reusable fill soils shall then be replaced and compacted following the attached-Gradin? Specifications. .,~
We recommend that no low to medium expansive clay soils be pl:!ced within two feet of the finish ground grade throughout the building area.
feet of
Highly expansive soils should not be placed within three
finish ground grade. If non-expansive soils are to be:
L~O!~l !iO. 73-41ni:
,~i$p ‘~ ‘:“y:-< Page 6 : ,:,, ox;,;, yy< a ,::
,&&tof Soil Investigation
m~ Laguna 1: ,,,~sgcxof Park D1ix-z :', Car&bid , California
used in the structural iills.(loca?ed :,.i thin trio to th rc c f cc ::
of the finish ground grade), conv?nticlnal concrctc slsh ilocrs,
spread footir>gs and continuous concrete foundations may ho
utilized for the support of the proposed residential t~i)E dw, llir,c:s.
.,If potentially expansive clay soils are encountered at finish grade
:: ,,; one cut or natural Urrund , these soils shall he excavatrd and
: raoved a minimum depth of two to three feet beneath the prc~,oscd ,,.~~ %,'~ ,-:Cfi,uish ground grade. The undercut area shall then he backfilled
~$&+th non-expansive soils up to the finish ground trades. ::or;- I', ~1.&cpansive soils are those which have a liquid limit of less than ,,, ,', 30, percent, ,i ,. a plasticity index of less than 15 percent and a &well index less than two percent when remnldcd to at least '(0 ~.~+ercent of optimum dry densitv and subjected to a normal loa:i of
,',one:psi. I :. * __ _ ,,, .> .,; ,~i~ : 4:'Cbntinuous supervision shall be maintained by members of our firm during the grading operation, such that proper inspections and tests are cor.ducted to insure that no potentia1l.r exT:ansive clay
soils were placed within the top two to three feet of the finish
ground qrado. Fjrld density tests will also he taken as required, at lcast every two feet of compacted fill depth to certify that
the fill materials have: been properly placed and compacted.
5. If it is the intertion of constructirc structures on the existin<?
low to medi--:, expansive clay soils (:wc- to six percent swell),
then it is rccor..nen~irti th;it the follrs:ing work be performed.
a. The proocsed continucus foundations shall extend at least 18
inches into the firm natural ground soils or compacted fill soils.
.,. The foundations shall be reinforced with tL:o i!o. 3 steel bars, ~': ",' '~:, .:-;' :*placed continuous throughout the foundations _ ,:: &,: Oi>C bar Shall he ,'.' located three inches from thr? bottom of thcx foundation and the
.other shall be located three inches from tic top. : <- .,,~ ;::&& .,; ;;;& oposed spread footings and/or piers shall extend a ninim!um +depth of 18 inches into the firm natural ground or compacted fill.
_~~ :r .:_ k. The concrete floor slabs of the structure shall be founded on “;.jj, at least four inches thick of non-expansi17e soils (sand cr
,: ,Xk, ,! ,e equal) and be reinforced with Fxh - 10x10 steel wire mesh. x2; ,_, <ii;.,,~ -, ?$T:, :~ ', a.. d-':::All non-structural concrete slabs such as driveways, patios, etc.,
_ i r,-$- ~ 'shall be founded on at least four inches of non-expansive soils. ~.,. .,, T', _ _ '~';,~p.~ 6. If it i ,.., s the intention of building on highly cxpansil.-e soils (in excess of 6% swe:l), then it is recommended that the followinc ;:: .; work be done. ~-'-a '.?a$,?,: ;, ,, .,: . *5-; ^ '2;~~: :;;ig I : a.,.The continuous foundations shall be founded a minimum dept!i wy ,of 24 inches into the firm, ';! :{g ,; natural ground or compacted fill soils. These foundations shall be reinforced with at least
C.e,,r,,.~ two NO. ,*&$>~,~y 5 steel bars: one bar shall be located near the toi, of Q$ ,s*& $ .~~~ : ~:~~:..y>~ the foundation and the other bar shall be iocatcd near t'ic L:ottom.
~*$$$g
W‘S +-.~~crf; Soil InX'estiqation
?ac;e 7
;id; NO. 73-41n8
j Park Drive 'd;;California
y:,-:$,l,-, : ,,,,’ <
:i f,,” :; T:,‘,This continuous 24 inch foundation is also rfcnnmendfd aiozrr
the garage entrance. The footinq and concrete
slab at the garage entrance shall be poured in one operation shall be rlonolithic.
;$-$ :: :b$Spfead footings and Piers shall he founded a minimun depth &GL?:of',.~24 inches into the firm, natural ground soils.
tj.fbotings
Spread
shall be reinforced with steel hars following the ~:;$.recommendatjons of the engineer of the buildin? proaran. $?;5:r:1 ,$" 'T s$.* . . ,,,.. $ ,&e;The:concrete floor slabs of the structures shall be founded $gj: .;.~ V on 'at least six inches thick of non-expansive soils, such %?%'.as silts and sands, decomposed granite, crusher run base, I kg&&~, and shall be reinforced with either 6x6 - 6/fi steel g&&&i:,:wir;'mes.k. or No & :j&:,~,,;, . 3 steel bars placed 48 inches on centers
~:yboth waVS .
~:gg .: -
a"?"Nb&struc6ural concrete slabs such as patios and sidewalks '$:i,,shall be founded on at least four inches thick of non-expansi
,_:; $1;~ .‘I:, ,, ,;i, :;
: ;;j; ~< y;,::. CT;., _
e-i’- ,.;.a. ,~.,‘~ 2,~;.
eve
$ soils .
,,
e: Moisture shall be re-established a minimum of 12 inches below the
footing qradc such that it. exists at optimum moisture plus two percent. This moisture content shall be certified hy William S. Krooskos & Associates 24 hours in advance of the placement of concret~e.
+he natural grounci and the soils expected to he used in the com;;acted fill Chavinq been compacted to at least 00 percent of
maximum dry density), will have a safe bearing value of 2,OnO
Pounds Per square foot. This allowable soil hearing value nay be 'iricreased one-third for design loads that include wind or seismic
,dnalysis.
::, ; ,,,, ,, ,. Settl&ent of the natural ground and compacted fill soils under the
‘proposed structural loads will he neqliaible and should occur during the period of construction. ,*::; ./., :
&a&al ground cut and compacted fill slopes of maximum inclinations
,,?f 2.0 horizontal to 1.0 vertical are stable for materials native
.To this site providing they do not exceed 50 feet in height.
~&e,comPacted fill soils that will occur within five feet of the
Proposed fill slope will oossess poor lateral stability, even
CIOU~Y. they will be certified to a relative compaction 0: Qr) Percent of maximun dry density or hetter. When there is fill, Proposed structures and other improvements such as walls, fences, patios, sidewalks , swimming pool, driveways, asphalt pavement, etc.,
that are located within five feet of the face of compacted fill .slOPe could suffer differential movement as a result Of the poor
lateral stability of these soils.
1 Investigation
Page E
Job :,:o. 73-4!OP
..;,>!,‘;g$;~
,~ :;;;11. p,ny backfill soils placed in utility trenches or beliind rctaini~nc:
walls which support structur.Cs and other improvements such as
I..', ,,~ :?;. 'patios, sjdexalks, driveways. pa\rement, etc., (other than.land- /,$l I :~
.: 2" Scaping) shall bc compacted to at least sn percent of maxrcur; cr:. _: I*:,:~.,, density.
:+:., ',~,~~f&~~~:~&~ passive earth pressure : to he used for the design of foundations
.~ ,-and footings to resist the lateral :i : :A@:& forces (wind or seismic) shall
,&based on an equivalent fluid pressure of 35n pounds per cubic '::C&i;:& -foot .; y$;*,:, >:~ The active earth r>ressure for the use and design of foun- ~. ':'datlons, walls, Etc., shall be hased on an equivalent fluid pres,sure
0 pounds per cubic foot. (level backfill)
cicnt of friction may be used hetwecn the soil~s and the
foundations and floor slabs on a factor of n.4 times the
dead ,,.load. This value may be used in conjunction with the passive &rib pressure in determining the lateral resistance of the
eonpacted fill soils and the natural g:-run? soils.
Adequate measures shall be undertaker. to properly fini~sh grade each
building pad after the structures and other improvements are in
place, such that the drainage waters from the improved site and the adjacent properties are directed away from the foundations,
footings and float slabs via surface s!;ales and/or subsurface drains towards the lol<er level of the site or to the natural drain-
eye direction for this area. rroper drainage will insure that
no waters will seek the level of' the: bearing soils under thn
foundations, foo:ir.gs and floor slabs which could result in under-
mining and differential settlement or uplift to the structures and
other improvements.
Ho:swimmins pools and other subsurface structures shall be
constructed in the potentially expansive clay soils (if encountered) Unless the design reflects their expansive soil characteristics Snd~follows the recommendations of the Soil Engineer.
Ai&SlOpeS shall he planted with an erosion resistant plant as SoOn &Spbssible following the grading operation, to minimize the
anticipated erosion of these native soils. .,
Foundations and footings of the proposed dwelling and.walls, etc., wh&founded fix?e feet and further away from the top of compacted
fill slope may be of standard design meeting the requirements of
the governing agency. If proposed foundations and footings are 'located closer than five feet inside the top of compacted fill slope, they shall be deepened one foot below a 1.5 horizontal to 1.0 vertical line nrojected outward and downward from a point five
feet horizontally inside the top of compacted fill siope. (i?efe!-
to Figure :~o.
Wrere daylicht lines occur under under proposed structures and/or
through the-midst of lots, jt is recommended that the entire iGt
1 Investigation
Page 9
Job ?:o. 73-4inR
feet of compacted fill exists
grade elevation. An alternative to tk,e above
gs and foundations t!irough the fill into the
ation shall be performed in accordance with the above
the finish grades as shown on the approved Grading
cations", Attachment i; and the
Citv of Carl&ad.
care shall be undertaken that the existin
emoved and the natural ground shall bc and compacted to at least 90 percent of
the natural ground shall be properly
bond cf compacted fill materials.
,I: ~i;3Aintintfous inspection will he provided by ur firm during the grading
~,' oprrat1on, such that our Final Report of Certification of Compacted Fiil
.~:'~~ill be properly prepared and r,rill include the following statements. w; ::
1' -:-I. 'The building sites t!lave been properly graded and are clear and
free of expansive soils within two to three feet of the finish
ground gracic, Or special footings will be designed to reflect this '1:. ~~, Clay condition.
he fill materials have been properly placed, compacted and tested
:,kO at least 90 percent Of maximum dry density and will safely
upport the proposed residential type dwellings and the other template2 improvements.
grading work was performed in accordance with the recommendations
marized in this report, and meets the general requirements of &;:&$::,; iithe governing agencies. @g ::
%IWTATIO;JS: &-. ,,i~ S&e ;&aco nunendations summarised in this report are based on the evidence @$Obtained from the 12 boring excavations, ~2~+,&$;, laboratory test results of the
1:;i$F4;aOOuntered natural ground soils and these same ~011s to be utilised in :~%&%the compacted fill areas; examination 0,~ 6 the site by Our engineering $j?$&2OIOgist and soils engineer; and experience with the soi,ls native to ,;.>C$$; i&is s i te . Uniformitv Of the underlying bearing soi~ls is assumed %k&%?!bet~een boring excavations which were performed.
ing 'the grading operation, qualified personnel from our firm will form an inspection of the underlying soils to substantiate the
Page 10
<Jo!.> Xo . 73-4i08
kuxnarized in the report. If a:>;; pecific action will be undertaken to
'kesponsihility of the developcl- or owner to inqurc that tk,e
summarised in this report are carried ou: in the :jelG.
, ~inclutiinc; subsequent reports and addendums, autonaticall;
c the builJind specifications.
rninq this report, please do not t.esitate
F >rvicc is sincerely appreciated.
Respectfully submitted,
WILLIAM S. KR@OSKOS b ASSOCIATES
7.
I'm J&&.&J. /&&g ,. ,, !.:illiG S. Krooskos, President KCE 11318
1
,~I $i!ix: *kii i '. ~";+y ,F;,sI&15) Enclosures ,,,.
B-12 1
N 0 --
This Plot Plan not to be Use,
existing and finish gracies. : existing utilities and other "Ps Built";,Plan. and the appr
t E G E N .? -__---.~
property Line------L---------------------
Approximate Location of Test Boring------.
Natural Ground Contqur ------_-- --- ----__-_
Existing Alluvium---;---------------------.
P L 0 T pi P L
Approximate Scale: 1" = 200'
I
LEGAL
Portion of Lot I Ranch0 Aqua Hedionda Map Ko. 023. in the City of Carlsbad,
County of San Diego, State
of California.
N 0 T&
s Plot Plan not to be used for engineering purposes. For sting and finish grades, property dimensions, location of
sting utilities and other improvements, etc., refer to the Built" Plan.and the approved Grading Plans.
REFERE
Tentative Map pre Rick Engineering
Robert C. Ladwiy
Dated:~ g/4/73
Lona Laguna II East of Park Driv
Carlsbad Area, Sz
California
Jcb NO. 73-4108
Figure NO. I
:*
* 0 +
1 5 - ,*..
-1
- ;.,
pi
10
k. .’ .
:. ,
15. ._ -’ .,, i,, _2! “,
20- @
~or,ng “is r Elevol~on -
Med - dense, damp, brown, ciayey fine
sand (SC)
Decse, damp, green-brown, SligiiY~ly
clayey sl?:y sand (ZW-SC)
: ::. $ ;
Bottom Of HCie -~/
Boring No. 2 -
Firm, moist, Srcwr., sandy clay
I
(CL)
\ TOPSOIL----
~cnse, damp, liqi:r brown, clayey
silty sand ( c. c )
Blow z~;un: for 12” - 55
Dense, dry, tan, weli graded sand (SW) Blew <aunt for 12” - 48
Bo:tom C= Hole - .I
I
LEGEND
Undlsturbcd Samp!e f Water Tab;e
DlSfurbed Sample (SM I Unrfted Sorl
Closslflca’~on ~~~~~-
- I.2 UT
$5 r /- < ;‘1 ” urn c
k;;” -
-
*Air dried *Air dried
Job Ko. Job Ko. 7X-4128 7X-4128
Figure h'o. II Figure h'o. II I i
-
: BORING SUMMARY SHEET ;;: %3 8cr4rg idC 1_ Elevation _ $5 0
bled. dense, damp, !.rown, siity sand
$~, ;, Borxw No. 4
Med. dexse, damp, brown, silty sand
& pebbles (Sk!j
Dense, sligk.rly damp, brown, silty & De"'j!ec ,i - I 2v.i
Blow count for 1.L' - 50 Eense, damp, brown, silty slightly
clayey sand (:;M-:i‘)
Becomes more clayey
Blow count for 1::': - 45
Bottom of Hole
Boring IGo. 5
i
Med. dense, sligh?ly damp, trown, silty sane ( s I",)
.I f eyse. slu3htlY pm?. srray;bry;lSC)
sllghrly clayey silt & sana
- S:
:2, $2 L?. 52: -
*P.ir dried -
7.7
-
74 -8.
f
LEGEND I
Undtslurbed Sompie 5 Water Table Jcb NO. 7X-4108
DJSturbed Sample :SM ) ihfled Soti Figure No. il;
Closslflcotlon
i,
I
:?,a,:,: :i': 2 yy; .z -b ", BORING SUMMARY SHEET G= iTw ,. iif qo 2 $2
Bcr,:;g !GC a E!evot!in _~_ :l!
‘: 2 VJz z
:’ ,‘,’ I, :, Med. dense, slightly damp, brcwn,
-z\silty sand (3M) .
5 - Dense, damp, drown, clayey silt & sane /_ (ML-SC)
,,,'_I _ . Dense, Siistitly daxkp, qray-brown,
..kti . . ..: fine San* (52) Bc:tom of Hole
r:. .” ,;:$ gg. .,
$g?{ $$ 9~~~~ ,., i .,‘, ‘-/ : A ~~: y$‘:;;~ - c ,,‘;; ;,~I!, 5 f’$.~., : *,a: .’
~~
._ i$irJ i;
,.<. ‘. ., ‘.
@ ,",15
'I,
,I::. 3'
-
-i
Bar iny No. 7
Med. 2er.se, camp, silt.; fine sand
\
(r~j
DEPS~, damp. brcm, slightly clayey
to clayey siit & sar.d (SW-SC-ML)
Dense, damp, qray-brown, silt & fine
sand (XL-SF)
Dense, siiqkt!y damp, light brown,
fine Sandy ( :~' i' J BlOW zount for 12', - 43
Bcttm of Hole --
-
121
-
-
.5.c
-
2 I i
I
s i ” 3
I
~ 1 -
i
-
.-
-
Ijo U;d,sturbed s,,;,: G EN :
@ ~Islurbed S‘,mFie
Wafer Table
&j Unffred Soil 7 '.: ,., .~ Closs1ftc0110n
Job No. 73-4108
Figure NC. IV
;p,, !A, ‘,’ ..,
BORING SUMMARY SHEET
507ng ‘4c AL Elevot:on _
Ned . dense, slightly damp, dark brown
silty fine ti med. San@ (SP)
Cer,se, cry, light ijrown, s:~ty fine to med. sari?? (l;P)
Sample shows -lean well graced sand
(SW) BlcW ,:cunt for 12’ - 60
Very ciense, Aamp, brown, sandy clayey Silt (ML)
Becomes more clayey
Bottom cf Hole -2
16 .Bi
7 g ,. “-
” 1 : “s
? .p 0’
LEGEND
j@ tindisturbed Sampie * Water Tobie
i.@) Eisturbed Sample (SW ; ilnlfled SCII
Clos5lfliotlon
J@b NO. 73-410s
Figure LG. V
i i -; 1 ;: t ‘, 1 ‘Y,,: 1 ,x 1 ” ,“.
1 ‘~a 1 ::
! :’ of ~I / ; .:;,, I ~, ,.,,,.~ -,: ..~,S
BORIN8 SUMMARY SHEET
fiorllg NC a Elevotlcrl _
Med. dense, dry, brcwn, silty sand
iSMj
Dense, damp to moist, brown, clayey
silt (ML)
Less clay
. . Dense, slightly damp, can, clean fine
(SP)
Dense, moist, dark brow, clayey silt
5amp, dark brown, slity clay
.j&f’ . . Jo ,<A. . ^,. ..;~ . . . :/;,/_ jc. .::, : :& & ,;a I ,, I~
light qreen-bruwn, fine
Barton of Hole /
*.;ir driec!
LEGEND
:;;Q
Undisturbed Sample f Water Table
DIsturbed Sample
;& NO. 73-4108
(SM ) Un,fied SolI Fiqcre No. VI
+ Closs,flcotlon
..‘::i:.~
;,;&!i;: b-p .A.
.,, y.:.
-,.,5:,,
_ ., ‘2
g;
,4::
L .-
,t
ii::
w 0
5
30
15
LL
2 .’ -0 mz
- . . .
‘_
. . . .
.
‘.
2
?
:
I c
F
2
0
- 2-j
f
. j _.
’
BORINQ SUMMARY SHEET
Boring IJo ‘0. Elevcflon _
led. dense, damp, red-brown, fine to
ned. sand (SP)
lense, damp, tan ~'3 light green-brown, !lean fine sand (SP)
iard, mclst, brown-green, clay (CiJ
3cttcTn cf Hole -2
-
Boring NC. II
Med. dense, malts:, t;rown, silty sand
(94) 100 9.0
Dense, dry, trcwn-gray, silty San2
(SM)
BC:~OIG of Hc;le 7
Boring No. 12
bled. dense, s:iyk:iy aamp, brown, c1.a:
ey silky sand (C~,~-SXn.)
5
,:10
: Dense. dry, light grray-brown, silzy
fine sand (SF)
.
1~~~:. . .*.
-
Dense, damp, dark Srown, silty sand
T
; -.
5’
j= : P
-
? $
t
7 .
*Air dried
LEGEND
Ur.dlsturkec! Somp!e * Wafer Tabie
‘hsturbed Somp!e :shA 1 Unlfned So11
Ciosslflcotlc~
Job NC. 7X-4108 Fig;ure NC. Vii
FILL SUITABILITY TESTS 7 i t_ 8;” .‘
MECHANICAL ANALYSIS . 3,. ^ .^ -^ -^^
60
40
20
0
3.
s-
1000 100 IO ‘0 01 0 01 0001 GRAIN SIZE it; ItiILLIMETERS
GR4VEL 1 S&ND OBBLE ‘ ) F ICIM 1 F SILT 4 CLAY
I I I I I I I
MAxlMUM DRY
’ SPECIFIC GRAVIT’
IIIIIIIIIIIln IIIi I MOISTURE CONTENT “/o
0~ IO 20
LABORATORY COMPACTION T:OST
40
ZEP.0 AIR VOIDS CURVES
‘h;.’ ?$+$ &;: SO,L 1 *-I, ,-. ““^“,CAT,ON El”,‘t4: TRENCH
NO DECTH $; TYPE 1 zl”IL LLU>>IT
:..
;E:, R’P ;;:I~ 1 Clayey silty sand B-1 5’ BT2 2& ~2 &?’ { Silty fine sand IB-5 1 115 '
:I 1::3 I clavev silt .c sand 18-6 I I 2’ I
~:/.“WELL TEST DATA I1 12131
~~1NIlIh.L DRY DENSITY (PC,) 98 99 93
:INITIAL WATER CONTENT(%) 12.0 13.3 14.6
~3.OAD’ (p 8 ‘! 144 144 144
::PER:ENT SWELL * ,, 3. 0 *3.6 *6.8
.i r dr i :d
JOB NO: 73-4108
3 7 I
2
~ci.,. ;g+ ,‘~
,’
I40 FILL SUITABiLiTY TESTS Jo i’
Soil Type 4
Soil Type 5
MECHANICAL Ah
3 3/4 4 10 40
IALYSIS
7nn
/
C E !N t@ILLIMETERS
SPECIFIC GRAVITY
ZERO AIR VOIDS CURVES’
I--. ‘ig >; ~0
Li:ORATORY C02&ACTION T:sT 40
SOIL CLASS!FlCATlON
Clayey silt & sand
Clean well graded sand
Sandy clayey silt
BORING TRENCH DEriH NO. NO. r
B-7 3'
B-8 10 *
B-8 15'
SWELL TEST DATA 4 5 6
IN171AL DRY DENSITY IpcO 92 - 123
‘INITIAL WATER CONTENT to/J 11.4 10.8
.,LOAO (pa f! 144 144 *Air dried
PERCENT SWELL '2.2 %C. 0
JOR NC’ ?3-4108
FIGURE NO IS
4
6
5
g .
;:
,:”
do
3
i
:$
f
i”~
:$,::, z~.:
rr ::
.’ .~.
I
;: :‘;* ,.
‘<_
..,>
~!
,,
2
.- q
I40
130
120
110
100
90
$0
*.
FILL SUITABILITY TESTS FILL SUITABILITY TESTS
DIRECT *AR TEST DATA I
I APPA’RENT COHESION tosf, I I I I I APPARENT FRlCTlCN ANGLE I I I
SOi1 Type 8 -l+++wk JdiL Type 8 . . - Soil Type 7
MECHANICAL ANALYSIS
100 3 7; 4 13 40 200
80
60
40
20
I I II I I II J
1000 IO@ tc ‘0 01 0 01 0.001 GR4iN SIZE iii MILLIMETERs
t
SILT + CLAY
SPECIFIC GRAVITY
ZERO AIR VOIDS CURVES
10
LABORATORY C02&ACTION T:OST 40
1.
‘i ;9 SOIL TYPE SOIL CLASSlFlCATlON BWNG TRENCH DE-TH
NO. NO.
“; :, 7 i Sandy clayey silt B-8 il'
-. 8 Silty sand B-12 15 ' i. ,, :: 1 I 1 I I I
i:
L,’ ’ SWELL TEST DATA 7 ~8
INIT!AL DRY DENSITY (pcfl 104 -
‘; I%tTIAL WATER CONTENT (*‘d 12.1
:. t LOAD ipsf! 144
;; :; (j ,: PERCENT SWELL 1.7
,...~~. ;:
C’ ~’
*?.ir dried
~09 “JO’ 73-4108
FIG!JRF N0 X
9
Normal Pressure '- Lbs./Sa.Ft.
1
I
I
I I
I c I I
Ii I I
I I I i I
WILLIAM S. KROOSKOS & ASSOCIATES Job Ho.73-4108
Figure N~.xJ
concrete Floor Slab
‘I, 5'-0" ,
I- Compacted Fill Sl
Maximum Inclinati
1.5 : 1.0 Reinforcement of
Engineer -
Concrete Foundation A..
.0p
.on
Compacted Fill
\
TYPICAL SECTION
( Showing Proposed Foundation Located Within Five Feet of Top of Compacted Fill Slope)
Job No. 73-4108
Figure No. Xii