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Home My WebLink AboutCT 72-13; Carlsbad Condominium Villas; Soils Report; 1972-05-15- - - - - - - - - - - - - - - - May 15, 1972 cT7;;1-J3 Larry D. Hunts & Asso~.,-A.I,A. 3024 Fifth Avenue SCT 02081 San Die&a, California 22103 Report No. 1 SUBJECT:: Phase f Soil lnvestkigatlon for the Proposed Carlsbad ” Condominium Villas, Harbor DrI~ve and Carlsbad Lagoon, ‘; Carlabad, California. ,Centlomen: ‘, : ,, In accordan& With your request, tie have completed the initial phase of the soil investigation of the condltfons of the subject site. We are transmitting herewith a report of this investiga- tlon; 3ha, analysis of ‘our, findings is intended to provide the required information to determine the feasibility of developing,the pro- perty ad planned, In general, ” we found the questionable lagoonal soils to be com- prised mainly a”!’ exceptionally loose organic and silty sands. These soils will be subject to relatively-rapid consolldatfon, will provide adequate strength with respect to the static’,loads, but are highly susceptible to llquifaction when subjected to re- 1at:ively low seismic loads, If you ,have aiy questi.ons after reviewing our report, please do not ‘hesitate t.o contact this office, This opportunity to be of service ia sincerely appreciated. Respectfully subMl;ted, SOUTNERN CALIFORNIA TESTING LAB., INC. CHW: j le cc : (4) su\,llll~~cu SlOlO .9.37 INSPECTtON l TESTING l RESEARCM l bEVELOPMDlT - 6280 Riverdale St. l San Dlego, California 92120 . Phone 280.4321 . - REPORT OF PRELIMINARY SOIL INVESTIGATION - PIQJSE I - CARLSBAD CQNDOMINIUM VILLAS HARBOR DRIVE & ACUA IIEDIoNDA LAGOON - CARLSBAD; CALIFORNIA - I. PROJECT DESCRIPTION AND SCOPE This report presents the results of our preliminary soil investigation for - the proposed oondominium development. The development is to be located - south of the end of’ Harbor Drive and adjacent to the Carlsbad Lagoon (Agua Hed.ionde. Lagoon) in Catilsbad, California. - It ia our understanding that the proposed apartment development is to’coh- - sitit of about ‘66 two’story condominium structures. The site is planned to bt graded and dredged to provide a meandering. land line fronting on ,’ - the lagoon. It is further understood that it is planned to piace fills over the existing lagoon to heights in the order of 24 feet. This investigation was undertaken to determine the physical characteristics - of t&e lagoonal a&Is and to provide sufficient data to determine the - feasibility of developing the property. 2. - FINDINGS AN~C6~~MENDATIONS 2.1 gfTE CONDITiONS - The site 9s estj.matcd tb be about 18 acres In size. It circunlscribes. - . - May 15, 197% Page Two - two existing subclivlslona that iliclLdz Harbor Drive and Baldwin Lane. Its rertherly portions slope generally to the northwest while the highest point IS found in the’ southeilst portion of the site. A hQh bank 40 to - 60 feet -in height slopes down to the south into the Aqua llediona Lagoon. The natural slope of the south facing hill is approximately 2 : 1. The - Incoon has been dredged along the southerly propel-ty line with the dredg- ing beginhl.ng at the: property line, The bottom of the lagoon along the - southerly property line is exposed at very low tide. ’ - Several reoidcnces,exist on the property along with their accompahylng _ utilities, 2 9 2 SOILS DEtiCRIPl’IO~ - -, The hiliaidc’soilc or those on the site above elevation of approximately - 10 are comprised of competent marine terrace deposits. The soils are of high strehgth and possess low settlement characteristics in both their - natural and redompadted statee, - The lagoonal soils were found to be comprised of silty, organic sands to a depth of about 7 ‘feet, Below 7 feet and to a depth of about 18 feet, the sands were found to be interbedded with ;hin ‘strata of silt. Below _ 18 feet a relatively clean sand was encountered. All lagoonal soils were found to be excepifonally loose 2n their native state and therefore they - are highly susceptible to settlement or consolidation, After consolidating, th,e soils were found to have adequate strength. The depth of the laeonnal - SdlG \~ill. vary fr*orn 0 at tile edge of the hill, to about 35 feet at the - f’arthest dj::tanc.e Yrom the h1ll:;jde along the southerly property line. - -‘- SCT 02081. ‘May 15, 1972 Pa [y Three - If the loads, are slowly added to the lagoonal soils, they should possess adequate strengtb’L support the proposed fills. However, dynamic loads ‘- such as ‘seis,mic loada will.cauee liquifaction and large abrupt movements of any fil.l.o that they ,might support. We know of no practical met,hod of - treatment to prevent this condition. Kechanlcal densifichtion (remove .- and ‘recompact 1, ,will alleviate, this condition. However, this procedure will require cofferdams, SUrcharglng with excess fill will. result in the - consolidation of these, soils, However, surcharge fills in the order, of 40 to 60 feet would berequired to achieve the proper densfty of the lagoonal - soils, We there&e ‘recommend that special consideration he given to the .- placement of structuros~ so that they ~1’13. not be affected if the proposed fili~ does move with a seismic loading. With 24 feet of ,flll as planned,’ - the ‘safe distance should be approxfmately 20 feet to the north of the ex- ieting lo font contour, .- 2.3 P~UNDAT~~NS A 2.31’ Oeneral : The native dense terrace deposit soils should provide an ~_, allowable bearing value of 2,000 and I.,500 psf for their natural and re- compaoted, conditiona,’ respectively, Due to the depth of the proposed - fill., the settlement resulting from the addielonal footing ioads should be in the order of l/2, Inch and therefore, tolerable, - , 244 SI,OPES ~’ -- - The ,proposed fill slopes s,hould provide an adequate factor of safety if placed at a’ratg.0 of 2 horl%ontal, to I vertical. above the water line and - at a ratio ‘of 3 horizontaLl to 1 vertical below the water line (high tide - line). - - May 15, 1972 Page Four - 265 ~‘l’TLEMKN~__OF~ PROPOSED PILI, -~ The s,ettlement ‘of the proPosed 211 feet of fill is estimated to be in the order of 12 C&es’,. Ti?is settlement should be quite rapld and shoul.d be - complete in ap~p’raximhtely /I months after the fill has been placed. The settlement should ,be checked after p’laoement by both piezometers and - settlement monuments to,insura that the settlement processes are complete prior to continuin$ With construction. We also recommend that piezometers - be Installed prior to bl.acem&t of fill. They would be utlllzed to pre- - vent’ an e,xuessive .pore,,preseure’ htiiltliup due’ to the ,fill being placed too rapidly. From the preliminary data available, we estimate that fill ,, - can be placed at an average rate ofapproximately 1 foot per day without ’ e%cebsive pore pre’ssure bwildiup. ,. : 2 .S EARTHwo~~K ,’ - Any grading’or earthtiork contemplated for site preparation should be ~’ accomplished in’ ac’cordance with the attached Recommended Grading Specifi- - oations, ,)‘, ~, ,’ ,. ‘:,, - 3, FIEJD EXPLOtiAT?ONS - - Four subsurf'ack explorations were made at the’ locations indicated oq the attached Piate’ No,, 3-l during AprJ.1, 1972. These explorations consisted - ,I of borings drilled’ by means of a rotary bucket type drill rig and two - oontlnuous tube samples. The explorations were conducted under the, direct super.vfslon ‘of our englnecring personnel. The explorations were carefully logged when made. These logs are presen- - ted on the following Plate Nos.. 3-S through 3-11,, inclusive; The soils are described in accordance with the Unified Soils Classification System as illustrated on the attached ::J~mplIfied chart , In addition a verbal ‘. . - ,, “’ XT 02081 ,’ rely 15, 1972 Page Five textural description, the wet colon, the apparent moisture and tlie density . or oonslstency+ara given’on the logs. Sol1 densities far granular soils - are given as either very loose, loose; medium dense, dense or very dense, The consietenoy of eilta,or clays’are given ai either very soft, soft, - medium etiff,~ stiff, very stiff or hard. - Representative oore’samples were obtained by means of a ‘split tube sam- I pler driven into the soil by means of the “kelly bar” of the drill rig. Samples of soft or very soft soils were obtaIned by means of a Shelby - tuba aampler., The energy required to drive the split tube sampler is / indicated on the boring logs ai the “penetratzion resistance”, The core - samples were ‘darefully removed, sealed and returned to the laboratory for .testing. - Disturbed samples ‘of typical Andy repreaentatlve soils were also ,, obtained and,returned to the laboratory for testing. - ‘ ,” ,,~‘; 4. LABORATORY TESTING - Laboratory tests’ were performed In accordance with generally accepted American Society for,Teating~and Materials (A.S.T.M.) test methods or - suggested prodedures. Representative samples were tested for their pi natural density and moisture content. The results of’ these tests~ are presented on the boring ,logs. fn addition, the gradation, plasticj~ty - properties, maximum densities; angles of internal friction and cohesion, and potential expansion were determined for typical and representative - samples, The results ‘of these tests are presented 111 tabular form on the _ following Piate Nos. 4-l’ through 4-2, inclusive. Consolidation tests were performed on four samples. The results of these tests are presented - In the form’of ‘cur,v&s on tbf follotqing Pl.ate Nor. ‘1-3 through 4-5. , - SCALE ‘:‘:” ‘li’ ~~'L>'J///// I / , . ,, tiALbW/N i&JE ‘. -- I- I ” ,,:: ,, , y-Q ..,, 4, ; 1, ‘,i a’, ; ,- ;< \ If J STUBE LOCATION --L %$Wl~ki~~ ,Ct,LIFONN IA TESTING UxfMtlol;Y~ IliC. 6lnO hlk’CtUJE.Lt slit! tl t&d rttti:o. cawtitw, ~2120 PLCI!? J‘i A:! IJropo:;cxl Cnrlsl~ml Cti.ndom,fwl.um Villao Hart~or lw:tve & Carl.sbad ta~wcm Car*lsbat1, Culifnrwih rw x s !! -, ---..- -- I --.. -_ [,,,Tt h-~?h-‘/? e-_-e.. II,t: r,‘n -----j-Y~;. ‘, I,*inII’l 1 1 1 1 1 1 L’ 1. 1 1 1 1 1’ 1 1 1 BORING NUP?BER 1 I_- DRSCHI!'TIQN ~~3;-Browry1, Moist, Loose, SILTY T L-dcLIYd wet saturated '(Road Fi127) @ray4 Saturated, Very Loose, SILTY SAND (Slightly Organlc,~'Bey,Sediments) ., ,. ,,, Darlc Cfroy, Saturated, Very Lootie and Very Sdft, fnterlensed CQanbc SILT,AMD SILTY SAND ,(Bay ,Sediments) ,I : L. 'Oray, Saturated, Loose, SILTY SAND BBcomes More Dense With Depth (Natural Tewaae Deposits) ? FOR LEGEND S5? PLATE NO. 3-,3 - F .t 1.0 1.0 9166 30.0 1.1.0 ‘~ 160 2.7 34.0 97.8 2454 .u !! 107.5 17.0 1oi.3 22.2 ., .’ 98.0 24.6 93'66 28.6 WERN C~llFOANlA TESTiNC *yf:zFf Proposrd Carl~t:bad Condoxinium Villas Hnrbor Drive ,& Car&bad Lagoon 1 Ca1nl~cl,ad, Calif’ornia ,, SAN DIE 0. CAl.ltOHNIA 921X 1 DATE h-72 .I- I 1’1,11’11 NO. 3-2 . ‘BORING NUMBER 2 DESCRXPTION Dronn & Gray, Moist, Loose to Medium Dense, SILTY SAND (2! Colluvial) Gray,,Saturatcd, Sitf'f VERY CLAYEY Light Gray, $l.aturated, Very Dense, SfLTY'SAND (;;;kf;;zlons and Concretionary 80.0 101.2 21.3 LEGEND‘- ,",, ,' Sample Location c 4: Samples Penetration Reslntance (Ft,Kips/Ft.) i, ,'~ 1 Y; Natural. Dry Dennity,(paf) MI 14tiatural ,Mbisture*Content (56 of Y)_ , SOUfhEI?N CALIFORNIA YEStlNQ lABORATORY, INC. 6280 Rtv~lfa~if bTRttif : . SAN OIEGO. CALIFORNIA 92120 714.280.4321 Proposed Carlsbad Condomlnlum Vj.llat: HarborO Drive & Carlsbad Lagooq Carlshad, California 1 1 1 1 1 1 1 J 1 -I TURE NO.2 DESCRIPTION Graj; Saturated, Very Loose, SILTY SAND (Slightly Organic B@y 'Sediments) ,’ T'UBE Nb. 2 ,,i CLAS9 I DESCRIPTfON Oray, Saturated, Very Loose, SILTY,SAND (Slightly Organic ,Bay Sedlmont). * I . SOUTHERN CALIfORNlA TESTING lAt3ORATOAY, INC. 62RO RIV!!RDACE SrREEt BAN DIEGO. CALIFORNIA 92120 714~280.4321 TUHE: LOGS -m-m- Proposed Carlshad Condominium Villas Harbor Drive & Carlsbad Lagoon Carlsbad, CalSforniri BV MRP DATE 4-72 -- ml3 NO. 02OP1~ PLAlT J;O. 3-4 -.- I &WIN SIZF P,~\!/~,~_~S~~~&~~JATT~~ EURG LIMIT’S_ ,‘-,,-r,~-.-zL-.. (U.S. Std Sieves) ,-~ B18, SAMPL.E, Bl @ B1 -i- 15 - 15.5 20-20.5' 25,-25.5 3 -&ii'. 3_ _./" 1 l/2 _ 3/4 --- - 3/8 ; $4 I 100, -’ -..-- --. ;#8: i gg .! 100, 100 +I6 96 98 99 :. 91 ++30 94 95 +50 19 76 .; 81 ! #xl0 61, 52 58, 9 .-u *-200 29 31 25 ,05mr?i 22 22 20 ,005mm ‘,” l,O, 10 ‘8 - _( .00lmm . . -,i’ .,, 7 7~ Liquid Limit -32 Plastil Llmli - 26 _I Plsbt’iclty fi’tdax NP 6 ., NP - \ Unified CLASSIFICATION 'SM SM SM DATE 5-12-72 mw NO. 4-1 SAMPLE ~, ’ OESCHI FTION Bl elf?’ UndiBturbed Loose,, Silty Sand Bl &21’ .Uhiahurbed Loose, Silty sand Bl @2t” Uridititurbed Loose,, Silty Sand T2 @3’ Undiaturbcid Loose, Silty,Sand --- ,‘_ Tl @l+s’ Jh-idi~turbed Laos&, Silty Sand _‘I,;, Anglo al Cohesion intcri-ml friction( ‘1 iniercc t (pst P 42 210 43 210 ii 180 43 210 34 70 ,, --. . . , SOlJTHEtRN CALIFORNIA T!tStlNG LMKJRATORY, INC. RIVt’tbALE Sft?EFt’ UIiTGO, CALltOHNI~ 02120 734.2f3.6134 Proposed Carlshad Condominium Vlllgs Harbor Driv,e & Carlsbad Lagoon Carlobad, California I - TABLE OF’ TEST RESULTS h.n..-..mUICLU-.-m-“ev -. - - ..-.-L -_ i...-..L i.-LjY .j .i--.---_- . 1,... _.i... i ,_. -. _-_ -. _-_ -- -- -.-..-_ -.-..-_ e --= e --= E-j- ’ :y:::.- E-j- ’ :y:::.- I ~.,--_ I ~.,--_ i-J-t- i-J-t- L--J L--J - - _-_--. ._~~_I_-_.-..- _-_--. ._~~_I_-_.-..- - - ---.. ---.. -- . . -- . . _l.__--_.--_.-_.. ._ _. _l.__--_.--_.-_.. ._ _. -,_ -,_ ,I ,I 1 . -j-g il. +~I $ II- 1 . -j-g il. +~I $ II- lF?k-l lF?k-l I.:,‘,: i 4 1 I I I I I I I , I1111 I I I I I - - - I 07 LOS 40 SOWllW?~~ CALIFOENIA TESTING l.AuOHATORY, INC. k!SO RlVtlVJALE 5tREET SAN DIEQO. CAI.IFORNIA 92120 ,’ 714.m!~.3321 Proposed Cerslbad Condominium Villas Harbor Drive 8 Ckl.Bbad Lagoon Carlsbad, California' I ?i? COlI~~OT,IDA~'ION',vs LOO T'RESSURE a! CllbJ DATE 5-12-72 3 JO0 110. 02081 PLATE NO . 'l-3 ._. ._._~ ~.~ ~~~ -.. .----. -~-.-~.. .I..-...- ,-.... I-_l_----.._ *-I i (KIPS/SQ. Ft.) ’ I% / i+, SOUTHERN CALIFORNIA TESTING Propoaed Carlsbad Condominium Villas r( 'fffy j 3 LABORATOHY, IM. 4;;:,;i ;, $9 Harbor Drive & Car&bad Lagoon i hLj. 6280 RIVEHDAL~ $TREfT Carl.sbad, California' '. G.1,: 9 SAN DIEOO. CALIFORNIA 92120 714.zbo.4%!~ 3 i- 8Y ” CHW DATE ‘j-12-72 ; j: CONSOLILIAT~ON VY ,Lotf PRESSURE -I_ JOII NO. Lm.--.- ,020al. PLATE NO . 11 -'I --w.--.&dyI-...., a--- -, 1.~ I I- ) L I i I- L L t L L 1 1, L 1 -1 I I / --+ ; f I - .- --.-. I I ++=I - _- - i ~mvs~. Fr.) 1 .Q&\ SOUiHERN CALlFORNiA TESTING Proposed Carlsbad Cbndominium Villas ^'@jy UEJOKATORY, INC. /, Harhor Drive & Carlsbad Lagoon 62130 RlVfXdAtE STREET Carlshad, California 1 l $ ‘SAN DIEGO. CALIFORNIA 92120 714.280.4321 2- Z COMSOLILU'l'XON v:; I~OG PRES,~JJ~E BY CHW ', DATE [j-,12-72 .--- t ~00 NO. 0 : 0 8 1~ PI A'lT' El0 i I . II-< ,‘! 1’1; r:,?l n I x A, PACE 1 JOB NO, 02G”l _w-1~- DATEL, 5-1572 . . . ..----. RECOMMEI~DEU GHADIFlG SF’ECIPICATIONS - Glwm~~I, Pl~ovrSICNs _-- - GENERAL IWENT: , The intent of,these specifications is to dstablish procedures for clearing, cnmpacting natural ground, preparing aress to be filled und plncj.ng and com- - pacliinp, fill’ soil. to the Lines and grades shown on the accepted plans. The recommendations contained in the preliminary soil investlgatlon report and/or - the attach,ed special ~prbdsicms ares a~ part of the recommended, grading speci- - ficatlans alid shall, auljetisedcl ‘bhe provisions contained hereinafter ,in the . case,of’ conflidt. ., \.a ,. - : ~NSFECTIOld AND TES’?ING: ,’ ,’ Y .’ ‘- A qualified soil engineer ahail ‘be employed’to inspect and test the earthwork ,, in accordanc&with ghese,: spociiicntions. It, will be necessary that the. fioil - engineer or his representative provide adequate inspection ‘so that he mti.y - certify that the workwas or was not accomplished as spccif’led. It shall be the responsibility of the’contractor to assist the soil eng3,neer and to - keep him appraised o,f work soiiedules, changes and new iriformation and d’ata ,,., ” so, that he may make these oertificatlons. - ,,’ a : If, &r ,khe opinion of the ‘Soil engineer, suhatandard conditions are encount- L e&d; such asquest,ion’able soil, poor moisture control , Shadequat,e dompaction, - adverse vreathci~, et&. , he ~911 be empowered to ei’ther stop construction until , the conditions are ‘remedied or corrected or recbmmend,rejectSon of the work. soil tests usid to Betermine the degree of compaction wj.3.1 he perfh+med in - accordance with 'the following American Society for Testing and %terialc testmethods:,, ,” ~, . - - fSfaximUtd Density and Optimum TIoisture Content - A;S.T.M. D-1557-70. D$hitj/ of” Soi: In-i?lace i A.S.T,M. D-1556-64, - i’l’1:::nI.X p,, PACP ‘? JOB NC, _ I DA1.Y 0201 I 5-llkLL---_ ~liF,‘l’Ar),A’J’IO:I OF AREAS ,TO RECEIVr; FILL: ^- c--a. : A31 vegetatiion; brtitih and dcbrls shall be removed, piled and burned or other- - dsc dispcsed ,of’. .Aftcr ‘clearing; the natural ground shall be scarif’lcd to a ..~ lepth of 6”, brought to the proper moisture, content, compacted and tested for the minimum density specified ,ln the’ special provisions or the recommendations - :ontalned ln the prollmlnary s'oll investlgdtion report. -/hen the slope of,the natural ground receiving fill exceeds 20% (5 horieontal to 1 vertical), the ‘original ground ‘ahall be stepped or benched. Benches shall - )e cut .ta a firm corn&tent ‘soil condition, The lower bench shall be at least :‘, 40 feet wide ,,and all other benches at Least 6 feet wide. The horizontal por- tion of ka’& bench shall be com&ated prior to receiving fill. as speclf’led -1ereinbefore ~f'or compacted natural ground. Qrbund slopes flatter than 20% ’ shall be benched “ti,hen ,co’nsidorcd, necessary by’ the Soil engineer. FlLt MATP:RIA.LA ‘, i, ,. , - vlatwi,als pl‘aced in th,e fill’ shall be approved by the sol1 erglneer and shall. 4e free of vegetable matter and. other deleterious substances. Granular flail 8hall contain sufficierkfine material to fill the voids. The deplnltion and 3isposltlon of.‘oversized rocks,,expanslJe and/or detrimental soils are covered ,ln the special prbvlslons; Expansive soils, scxils of poor gq.datloi3 or - strength char&Cterlstlcs may be thoroughly mixed with other soils to brovide -sati~sfactary riil material, but only with the explicit consent of the soil engineer’. f - PLACE?0 ANI’I CONPACTICN OF FILL: ‘Approved ,filI material shall be placed in areas prepared to recelve’flI1 ln layers not to’:exceed 6 inches in compacted thickness. Each j.ayer shall have - e tinlform moisture, content in the’ range that will, allow the compaction effort ., - ,, ” ,’ I -,FPEidl.lTX A; PAti& 3 ‘, JOR NO, OXO& I DATE+- ri-lr;-y? ,o .be effic~icntl.~ ,apfill,ed to acliie’ve. the specified degree of compaction. Each layer shall be uniformly compaated to a minimum specified density - fith adequately si?~ed equipment, either specifically designed for soil, compaction or of praven’Peliability. The minimum degree of compacti.on L:~ be achieved s ,specified In el.ther the special provlsicns cr the re- -:ommendations cont&ined in the preliminary soil investigation report I “ield tests and lnspectiona’to check the degree of compaction of the fill. will be taken by the ,sbll ,engineer or his representative. The location -.nd frequency ‘of the test&hall.‘be at the sol1 kngineer’s discretion. In xeneral, the density test&will be made -n vertical rise and/or 560 cubic, yards at an interval not exceeding 2 feet of embankment. .. W&ON LIMITS’: -WI.1 shall not be plaokd during ‘unfavorable weather conditions. When ‘work 18 interrupt,ed’,by heavy, rain, filling operations shall not be resumed unt.il -:he :.proper moisttire, ‘,oontent and density of the fill has been hchicved, Dam- age resuI.ting:from weather shall be repaired before acceptance of work, - ,I,, ‘,,, ~2333l CdNllITION$: : ,’ : - :II the event that conditions are encountered during the site preparation ant3 ~constrhtition that were not encountered dur?ng the preliminary soil l.n- . festigatlon,’ Southern California Tefitlng Laboratory, Inc. assume5 no rcspon- -libility for cdnditians encountered which differ from those conditions found hnd descrided’in the prellm&ary soil investigation report, - - .- fWOPlkl~:M3~D GJJ&~ING SPEC~~TCATIQii~ - Provisions 6PEiXAQ - The minimum desroe of compaction to be obt&ined in compacting natural ground, in the compacted fiU., and in the compacted backfill sha1.1. be - 90 percant. &trimtifitailv axpacsive soil is defined as soil which &Cl swell - .- - - more than tihree percent against a pressure of 350 poui& per square foot fYom,a condition of 90 percent of maximum dry density and opthuii moieJcurs~ content eo sitturation. oversized.,fiJl,mater~ ie deftied as rocks or lumps over six inches in diameter. A'k least 40 percent of the fill soil shall pass through a NO, ‘4’U, ,S, gtanaara Sieva. ,~ ,Rnsi’ I, or{, &: Where transitions between cut and fill occur within the prapos&d building )jad the cut portion should'be undercut a mini- ,, - 1 mum o~?'one 'foot beltiw thhe base of the proposed footings and recompncted tie struatu&l backfill. - ,i.. . - ‘, C - . - -.. - - - - - - - - - - - - - - - ,,, UNIFIED SOIL CLASSIFICATION CHART SOXL ur3scRwJ?5org GROUP SYMROL 1. COARSE: GRAINE;D, More than half of mat~erisl'is larger than No. 200 sieve size. CLEANGRAVELS GRAVELS More than half'of coarse fractiori'ie larger thanNo. 4,: ', ", ~ eirvo size but emallar than 3":. .' GRAVELS"WITH (Appreciable :of fines) 1 ,, ,, ,, : qb&jg CLEAN Snwnd xe than half ,of, coarse fraction iB ,, omallet than No, 4 eieve rize. SANDS WITH PINES (Appreciable,amount ~of finks) ,, FINES ” amount 11." FINE GRAINED; More than ,' half of material is'smaller than Na.'ZdO Bleve'aize, SILTS AND CLAYS ML ,: Liquf~d Limit lees than 50 S.IlX'S AND CLAYS , Lfqtlid rimj.t greater than 50 HIGHLY ORGANIC SOILS GP GM GC SW SP SM SC CL" . . OL Mn CH OH Pl! ~I$& NAMES Well graded gravels, gravel- sand mixtures, little or no fines, Poorly graded gravels, gravel sand mixtures, little or no fines. Siltygravels, poorly graded gravel-sand-silt mixtures. Clayei gravels, poorly graded gravel-sand, clay mixtures. Well graded sand,gravelly sanda,~ little or no ffnee. Poorly graded sands,gravelly sands, little or no fines. Silty Bands, poorly graded sand andsilt mixturee. Clayey Bands, Band and clay poorly graded mixturoe. Inorganic silts and very fine sands, rock flour, sandy silt or clayey-silt-sand mixtures with slight plast- icity Inorganic clays of low to medium plasticity,gravelly clays, sandy clays,Bi.lty, clays, lean clays. Organic siltB and organic silty clays of lm,plaBticity Inorganic .slltB; micaceous or diatomaceoua fine sandy or silty soils, elastic e41ts. Inorganic clays of high plaStiCit Organic c aye of medium Y' fat clays., to high plasticity. Peat andother highly orgenie soils. ~'SOUTHERN CALIFORNIA TESTING LABORATORY