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Home My WebLink AboutCT 73-18; RANCHO DEL PONDEROSA UNIT 1; SOIL INVESTIGATION; 1973-09-13• • TABLE OF CONTENTS TRAIISMITIAL LEITER SCOPE fIELD INVESTIGATION LABORATORY TESTS SITE. SOIL AND GEOLOGIC CONDITIONS DISCUSSION CO~jCLUSIONS R£COItlEtlDATIONS LIMITATIONS FIGURE 1 -SITE PLAN FIGURES 2. THROUGH 2 THROUGH 8 -LOGS OF TEST BORINGS FIG~RE 9 -GRAIN SIZE ANALYSES AND PLASTICITY TESTS FIGURE 10 -CONFINED Cor1PRESSION TEST fIGURE 11 -LOG OF TEST TRENCH • Page 1 2 2 3 5 7 9 11 WOOOWARD • GIZIENSKI & ASSOCIATES CONIULnNG lOlL AND roUNOATION CNCINUas AHD QIEOlOQISTS ,,!:' . . "-.' '. 3467 Kurtz Street San Diego California 92110 (714) 224-2911 . e· .: .. ,. WOOD.WARD -'GIZIE'NSKI . & ASSOCIATES CONSULTING SOIL AND' FOUNDATION ENGINEERS AND GEOLOGISTS An affiliate of Woodward -Clyde Consultants· September 13, 1973 Project No. 72-253 Ponderosa Homes ~ 2082 Business Center Drive " Sufte 100 Irvine, California 92664 ,Attention: Mr: Donald Gayle In accordance with our authorized agreement dated June 12, 1973, we have ,made an investigation of the underlying soil and geologic cOnditions ' at the western half of the proposed Rancho del Ponderosa development (Weigand Property) located in the 01 ivenhain area of San Diego County" California. The resul ts of our study have reveal ed the presence of what appear~,_~ , this ,time to 'be a maj.o.r..-i:a.uJ:-t-Z.one trav.e..rsin.g_t./»e-sjl"e .•• =-~'f"au1t zone cuts tne southeast corneLQf_tb_e_P-rQ.~ty-an£C~~JAttds...J.nto_ the e,E,s1;,ern half of the {j~ve-~ which has previously been studied by our fjrm and. the---resurtS--;ssiTea-fii a report-dated NoVember\ 11; -1972,. ~I6~_pr~_~e .. , of thE!. f[iIl,~t-was not~p-p..a.r-ent-a;t-ctlre:...:.fjm~ ,QJ.;~f(~r.~,vi9US. investi gatfon.· ":~i;~' " ~~.~., The directionof-fl1e .fault and-tb~L...aP-p.r-0?limate: extent of .the·-@'f ~one"," .:-\,': "'.~; has Q,~en"aeterm·ine(l-;-h-oweve-rTrfO-dl~~ta11ed'5.tua : attnlS time has been .... ... made fri-:-r~gara-tOage or actlil ,.Qf-t Dau' . ~No ,Qfn:e.t:·~m~joraa'ier_se· , . soil and. geCirog-i~'-Eondltl:Ons-were. r.e):eale·d,by 'our investigation. . --------.~-'-- The accompanyi~g report presents our conclusions and recommendations per- taining to grading' of the site, as well as a preliminary discussion of the effects the ~t_zon>e~y~ .have on the __ d_e'yeJ_opment __ o_Lthe_p.r:op~~.ty .' . Also incl uded ar the results. of-'Ourstib-surface exploration and 1 aboratory . tests upon w_~i~Q ou.r,.!=o!1~}usions and recommendations_~r:~ ,bas.ed. , ,----, _. \-<' -, ' The ,engineer a~sign.ed t~_ th1s.,prQJ~!;t..J~_R~uJ our firm. WOODWARD-GIZIENSKI & ASSOCIATES ------- LJL/RPW/mf (4) Attachments I, . ') . ~ ".: !' . Project No. 72-253 'SCOPE' This report d~scribes an investigation C?f the ,underlying, 50;'1 and geologic conditions at the site of the western half of,the prQ~osed Ponderosa Homes deve10pm~nt located north and adjacent to the, 01ivenhain . ' Road,. approximately 1500 ft east of Jts ,jntersection with E1 Camino Real in the 01ivenhain area of San Diego County, California. , The purpose of the invest{gation is to determin'e the general , physical, characteristics of the subsurface soils and geologic 'units, ~~' "-~ , -._. --, -, ---- including general excavation characteristicso,f the formational materials' and the approximate depths and limits of potent~a11y compressible alluvial and potentially expansive clay soils, if any; the general recommendations for site grading and fill compaction; the most suitable depth and type , of foundation for us,e on the site; allowable soil bearing pressures for sO,ils in a natural ,undisturbed state, and as, compacted fill; and allowable " , heights al"!d inc1inati9ns for:-cut ,and' f{ll' slopes. ,,"--, . :'.''',:','.-'::.:)J/' . .., -~ , .~ It is 'our' understand,i og that the proposed construct; on will ~,~ , ,', be limited to residential wood frame structures with relatively l,ight loads. It is further anticipated that conventional shallow footings , , will be utilized for the support of structures and that concrete slabs- ,~n-grade will be utilized. The available tentative grading plan provided us entitled "Specific' , ' '---' Plan and Tentative Map of Rancho Del Ponderosa," dated May 8, 191'3 and, ----------------,_. -~." .. ,,, --.' --" '-. -', .. -.-. ....,.,~ -,~ prepared by Rick Engineering Company indicates that cut'?lnd fill slopes (for both western and eastern parts of the property) will have maximum heights' on the ~rder of 25 and 100 ft~-Iespective1y, and slope inclinations ranging . ~'- " -;. . ,":,-,: . 1 J. ,.'.-',. WOODWARD· GIZIENSKI & ASSOCIATES CONSULTING lOlL AND 'OUNDATI,ON ENGINEERS AND GEOLOGIS/:,)) , ",,~. r--~' --:'Pr=0:'je:-::c::t-:N7:0-. "":;7;:::'2--:2:;'5:"3 ---------~~--~--......... ....---..,.-----~. _ .. -. -, • ',from 3 to 2 to 1. Some 1-1/2 to 1 inclined slope~ are a.1.~R,p1anned with maximum heights of 47 and 27--it: respective1y .. 'seve;~l'~~~~~~-;~~~on cut --_..... --_ ....... -~.--~ ----------~-. --:....~-- -,---.~" -... ---.. ---' .--. .-~ , and fill slopes are ind~ca~~<!_~~vi~g ~n~linatio~~ _~!~~~~d maximum overall heights on ~he order of 45'ft.' ~ c FIELD INVESTIGATION The field investigation was performed at the site on August 23, 1973, and included a visual reconnaissance of the site, the dri1lin~ 'of 12 test borings and the excavation of 1 .test trench. All field work was done by or under the supervision of an engi~eering geologist from our o~' The 'test borings wer,e made wi~~~.-=in!-A1amE!-ter ... ~..911~tI']J!"0.Ys fli ght power a'uger and the test trench was made wi th a tractor mounted '--------.... 24-in. wide backhoe at the'approximate locations shown on the at~ache4 Site Plan and Geologic Plan, Fig. 1. Field boring logs were prepared , ___ _~ ____ -"'if-. • _' ___ • ,' ___ ~. '~ by the geologist on the basis of an examination of the samples secured , and the excavated material, as'well as the action of, the drilling equipment. "c' , .' The '1 ~gs of tes~}Oring'S ~p'r:s~~t~d_.· O~Fij~}_~hrOugh ~ ••• ~re bas:d_ 0"_' . . . •.... '.' ..,p~ ,:an inspection of the samples secured, laboratory test'results and the ~--------:---. ..--------.-------.------~, " . field boring logs. -----------Th~boringS w~re approxima~ely locat~din'the field with the ,aid of the aforementioned tentative grading plan and topographic maps on file.' .LABORATORY TESTS The soils encountered in the test borings were visually classified , and evaluated with respect to strength, compressibility characteristics" grain size, mois~ure content and dry density., The visual classification WOODWARD. GIZIENSKI ," ASSOCIATES COMSULTING lOlL AJIID 'OUNDATION·'NG1NUIIS AND G£OLOGISTS , e . ' .. ' . , J' " • '." • ~ ~ ,...' "', ," ,Project No. 72-253 Page 3 ' ' • was substantiated by gr:ains!~~_ ~nalyses __ ar1d d~_tJ~rmfl'}aj:t~mJlf _21a~ticity characteristics. 'Strength and compressibility ch!tra,cterl$:t:iC:$_W~r~( evaluated, '--,---.-~---.--'-----' -.' -------~, by a direct shear ~est and confined compressi~n t~_~s on selected samples -------~----------~'--~--' , and by con,sideration of the dry dens~ty and moisture content of the samples, ... -.--. __ ._.--------------._-- the penetration resistance of the sampler and the geologic' cha,racteristics' of the formations. Previous laboratory tests contained in the soiT investiga~' -------. ' tion report' for the eastern portion of the property. were also considered 1n this rega.rd. The results of the moisture content, dry density and direct shear test results are shown along with'the penetration resistance of the sampler at the corresponding sample location on the Logs of Test: Borings., The results of the 'grain size analyses and plasticity tests are found on Fig. 9. The confined compression·test results 'are shown' on Fig. 10 • . SITE,' SOIL AND GEOLOGIC CONDITIONS . " ',: -.. " . ~', , k·.' " -;. ... :. " " ' .. :. The subject site con,sists of an approxfmate 60 acre parceL . . ,"; .. " ." . .' ':-.,;' .; .. ~. ~;.\~ ,()f fand situated on the lower and middle "northerly s'lopes of a westerly' draining tributary' to Green Valley, northeast of E!l,~initas, CaliJornia'. The elevation of the site ranges from 95 to 225 ft' (USC and GS Datum).' ---....... -~ ------. Two major subtributaries drain the site at the north and south ,property boundaries and extend 'to'wards the. topographic high at the center of the ,site along the eastern boundary. In g~r1eral ~ the s,ite is co'(~ied ..RY. a moderate growth of brUsh, although some patches support no vegetation. . -'--' -" ---~ ----. ,. ------ .·An examination of County Topographic Survey Maps indicates that a ,poultry ranch formerly occupied a portion of the northern half of. the site and our visual inspection indicates that some shall,pw,cutting and filling' WOODWARD· GIZIENSI(I & ASS'OelATES COHIU~TINfI SOIL AND 'OUNDATION 'NGINEE!!S AND GEOLOGI'//) .' ~ " , ,~ . , ; ~." - -..... _ ' .' ·e'-. may be associated with this area. A fill pad has' been c.onstructed near . . the eastern boundaries, south of the. highest portion of the site. The ----........ -----....., , . fill is on the order of 20 ft in maximum thickness an~ an approximately , 8'f~high cut bank ~xists at the rear. A"s"!~ll earth dam was noted in' the subtributary in the southern portion of the ~ite. '---~ ~ --------~---.. -~ ---------.---. -----fhe natural subsurface soils an,d geolog;'c formations on the site. can genera~ly be divided into the following groups: (1) An overburden consisting of a mantle of residual soils (topsoil and underlying clay) over most of the site. (2) Alluvial-colluvial soils in the major subtributary draws which are recent soi1s~ usually reworked soil mantle, deposited by the action of water and wind, in the case of alluvial soi1s, and .gravity , in the case of co1luvial·soils •. . . . (3) Underlying the overburden and alluvial-colluvial soils are found massive poorly to moderately indurated sandstone, which appears 'to'be part ~f the .Torrey Formation o.!' ~ocene Age and a laminated. claystone-'. ' .. ? mudstone Unlt, WhlCh appears ·to be slmllar'to th~e1 Mar Form'atlon, ~ tJG.!.JS, a~e-:----" _. .' . . " .,...... .. The topsoil, where present, ranges frol1J. 0 to 4 ft in thiskness and' is composed of loose, dry, porous, sil ty fi ne sand., The re§.i dua 1 .. ~ .. :'. . : ---:-----~:::-~.-___ --'<-"" .. ,~":. .. ~ ~.' -~:" -:-',. -.. -~ '.---:~ ~:--;.,~-._., '.: . A • :~ •• _:>,;..:~' ~'.~ , ;" c1 ay beneath the __ tops oj l~ran:ges:"'i·n,~-th.i:ckness ,."~roin~~O ~to -5~:ft;,and-.:j.s, .. generally. '.~ .: :/~~:~; : ,,; . • ' ,-, ------.----~~ ,. ~ .' • _,_t ~~',: ".', a. ,si.1ty to sandy clay material •. The respective average thicknesses of . " .. ' the topsoil and. the clay is on the order of 1 and 1,-3/4 ft, respectively. ,The alluvial-colluvial soils are found on ·the bottoms of· the major'tributary . ,draws and,borings indicate that the materials consist of porous, sandy clay and silty to clayey sand, existing' in thicknesses ranging from 3 ---.-;.' _... -' to 8 ft. These potentially compressible soils are shown on the attache~ . ' Fig. 1. The formational ,soils are relatively competent materials and the sandstone will provide significant quantities of select material. . . . No groundwater was encountered in the test borings or test WOODWARD· GIZIENSKI & AS,SOCIATES CONSULTING $OIL AHD 'OUND"TI~ ENGINEElIS AHD GEOLOGISTS (j) . . ' "-. " t'age ::;" " e,' 'e' pits qt the time of drilling~ No marshy areas o'r, water seeps w~re noted 'on the site. During. our field inv~sti~ation, "a ~au.lt was ·discovered traversing~ , . the southeast corner of the site and extends into the eastern half of ,.------_._--.............. ------" ........ '.. ' ---the proposed subdivision. The fault was first suspected to exist du'e. to the difference in materials in two road cuts on either side of a·sma1l . ~-----._----------.-----'".-.-------------. ---'..~.....-draJ~age gully. The westernmost road cut exhibited Del Mar c1aystone- mudstone materials~ while across the gully in the eastern roadcut, sandstone , ' ---~ .. -~ -;------- , of the Torrey Formatl0n Was' ~~Ro .. ~!!~. A test trench' was excavated and' the fault zone was exposed in the trench. The zone appears to consist of numerous normal faults in a graben-like structure, is approximately 40 ft wide and generally strikes north 35° east to north 50° east with dips " of 49 to 80 degrees to the south and north. The thickness ,of the gouge within the fault trace ranges from essentially none to up to 12 i'n~ of crushed silty claystone. The approximate location of the'zone,based , , u_'~ ", on' our present knowledge" is cshown .. on" the, attache~ Fi g. 1. , ,'. ", .' ,/.\ .' ... '.' -:: • ~."" .-: J' '. ~, -': ..... , .... : •••••• ~'I. ,Y • ; -. . r ~ >. ' •• DISCUSSION ., -/. -," ~" .-:.: :"':.-". ,'~' ~ , • . >~'. .~.; " . '--;:' ~ .. ,' ", _ .. : -. .' ' ",', " Among the items which should b'e consider:-ed in the development ,of a subdivision are the stability of cut and 'fill slopes,; the vo1um~ . I change characteristics of the s6i1s, such as potentially compressibla , ---------.. -----------------~..-- , alluvium ,a~d' expansive clay_soils; the ease'o'f excavation 'of mate~l~ . "---------~ ---( in the cut are~ and the relative .coll1pacti9.~.1'.~g.ui.red in the fill,§..~ " In the past few years an added crlteria of increasing importance, is the occurrance nf faults and their effect on subdivision developments. A review oft.hg g,rading.·plan-i·nd·;'c::ates" .. that-cut_slo,p.es wou1 d' ~. _ .. -, ----. .......... --- generally be nominal in height and provided the material in the cut face ----,-~ ----------._.. __ :..-___ -_________ .. ",--1""-----..;' ... _ WOODWARD· GIZIENSKI & 'ASSOCIATES· CONIut.T1He lOll, AND FOUNDATI0f4 [NGINUIIS AND GEOLOGISTS ")., " , Project No. 73-253 ' Page 6 ,is competen~, unfractured materi,al, the stability of cut slopes should not be of great concern on this site. Several high fill slOpes are proposed and it may be necessary to build the outer zones of these materials out, -, of certain soils on site, such 'as sandstone in lieu of claystone,' tn order to maintain adequate factors of safety against deep-seated failure.", -- .Pote~tially compressible alluvial soils are generally minor in occurrance and should not require other than normal consideration. 'There are relatively thick clay soils in ,the lower elevations which may be exposed in areas ,', of shallow cut and fill and moderate undercutting and 'replacing with nonexpansive soils will be required in these lower elevation areas. We did not encounter any "difficult to excavate-rock" on the site and our experience ,in surrounding areas indicates that little or no heavy' .c:== ripping will be required. In regard'to the occurrance of faults across the property, one has been discovered and it has been described in a previous ,section;, in this regard; there ;-s als'o a possibility ,that other faults ,exist' and .<:' ',"" , . ~.-......' . .' ., . , ... . " . may be unc~vered during the g'rading of the, site. ,,: It ',1's, ,not known at :, ':: ":,: ,~ . . -' -. -, ' this, time whether the fault, observed 1'5' active in nature. If the site is to ' be developed; possible lines of action include: (l) 'A'statement could be included in the Real Estate Report r~garding the presence of the fault, with no explanation of activity Or possible re-occurance of movement.' " (2) Further investigation of the fault zone could be made by 'our firm in an attempt to determine its age and to outline in more detail the extent and offset within the zone and the presence and characteristics of gouge and weak ,materials. ' Following this investigation, conclusions, would be presented relati've', to .the activity or inactivity of the fault. If the' results of the investjga-' tion reveal that the fault has not moved in the las,t approximately 10,000 , ,,' WOODWARD· GIZIENS'K'J & ASSOCI,ArES , COICIUUINa' SOIL AND fOUNDATION t:NQIHlEIIS AND Q£OLOQISTI , ~ i; . . , P,roject No. 73-253 P,age 7 '. years it can generally be classed as inactive in::nature with, future movements very un1i~e1y. Some design and construction ,consideration for the ,weak, material in the zone may be necessary in cut slopes and for fill foundations , and in lots for house foundations. If the results of the investigation indicate that the fau'lt has moved in the last 10,000 years, it should "be classed as active. In this case, it may, be necessary to design a green belt or place a street system along, the zone ,such that the fault does not cross lots. CONCLUSIONS (1) The results of our investigation 'indicate the ,presence of a fault zone across the property which extends into the previously i-nvestigated eastern half of the subject site. The activity of the fault, is not known a1; this time and more study will be required in'this regard. , , Other than this, no other major adverse soil conditions were revealed that ~ , <. would preclude the developing of~lans for the'subdivi's;-on. ' , . { . , (2) the subsurfac~soils on the 'site can gen'erally b~ divided" \. \~nto f~ur groups:' "'-'''' '7 , " : :', ,,,, 'l -, ..£]" \ ,(a) Existing fill -no records are available'to, our knowledge .~ that would indicate whether the fills were compacted or placed under control- led conditions. They should therefore be considered unsuitable for the support of structures or any new fill. ' --' (b) An ,overburden consisting of residual soils composed of topsoil and clay covering most of the site. The topsoil is generally thin but the clay is irregular in occurrance with the thickest portions covering the lower elevations. , ' (e) Alluvial and colluvial soils occur on the bottoms of the draws and along the lower slopes of the tributaries. These materials consist of sandy clays and,siltY,to clayey sands. In general, only the alluvium on the bottom of the tributaries was noted to be porous in nature. , (d) Formational materials occur ,below the ov'erburden and alluvial-colluvial soils, consisting of massive poorly to moderately .' , WOODWARD. GIZIENSKI & ASSOCIATES COICIULnNQ lOlL AIIO FOUNDATION ENGINEEIIS AIID GEOLOGISTS , '. -,,- .:. .~ • " • ,J : -I-~ ..... ,. .' ;~. ~. ': • i· . Project No. 72-253 .indurated sandstone, above approximate elevation '·140 ft in the southwest corner and 160 ft along the northern boundary of the si.te, and laminated claystone and mudstone below these elevations. (3) The alluvial soils as indicated by confined compression. tests range from low to moderate in potential compressibility. ~xcessive differentia]' settlements could occur shou,ld these materials 'become saturated under load. (4) . The soils en~ountered on the site r~nge from high1yexpahsive :in the case of the residual 'clay soils at the lower elevations and the -, claystone-mudstone formational unit, to essentially nonexpansivein the case of the massive sandstone unit. Most of the excavation proposed . will be in this latter materiaL (5) Based on the results of the test borings and our previous experience in the. general· area, it is our opinion' that the 'formati'onal sandstone and claystone-mudstone materials on the site can be excavated by medium ripping with' heavy duty excavating equipment. :. -, -':. _. -', (6) , It -is' our opinion that-s1opesbu-ilt-jn 'accordance:'with ,'," .... ,:-:-":,- > ~ ",' .' • • ~ ,', • /. .' the plan's arid specifitations, the tabie be1~W, ·and:,;~he.fol10~in:~· 'recommendations',' -C" will have adequate factors of safety'against deep-seated slope failure.:, . -. The table is based on a minimum static fa~torof safety of 1.5. Type of Ha (a1lowab1e unsupported slopeheight)* ··Slope 3: 1 slopes** Cut Slopes ~- Fill Slopes 100 ** overall inclination 2-1/2:1 slopes 2:1 slopes 1-1/2:1 slbpeS' --70 60 75 55 40 *this criteria can be extended to the eastern half of Rancho del Ponderosa . - WOODWARD· GrZrENSKr & ASSOCIATES COIIIULTlNG lOlL AND FOUNDATION [NGINEERS AND GEOLOGISTS ,-- -., ", " ~age 9 e· Compacted fill slopes founded on the 'claystone-mudstone, unit will require, "special keys and inspection of keys:to determine actual geologic conditions' prior to placing compacted fill. In addition, the material that will compose both cut and fill slopes is highly susceptable to erosion ,and will" require careful planting. Fill slopes should be carefully compacted, . , by backrolli.ng with sheepsfoot during construction to help control erosion.' , RECOMMENDATIONS . ' (1J' The ground which will recei,ve fill and/or residential : structures will have an adequate bearing value to safely support the proposed loads when treated as described in the attached "Specifications 'for Controlled Fill" and the recommendations below. -It is recol1Jl1ended that conventional spr~ad or continuous foo"tfngs for residential one and· two- , story wood fraine stucco structures placed on nonexpansive undisturbed· ' native soils, or properly compacted nonexpansive fill, be designed for the following allowable soil bearing pressures. " . ,'" . ~-',; .. '. .. -,' .' ,,' , , Allowable Soil Bearing Pressure, psf ",;' . .' .. ~. , - ~ " ., , , Depth*· " . Natural Undisturhed Sandstone Compacted" Fill 12** 4000 2000 18*** 5000 2500, * Below lowest adjacent rough or compacted grade • . ** Minimum width should be 12 inches *** San Diego County minimum requires 18" depth and 15" minimum width for two-story structures. (2) It ts recommended that loose ~~(0t:' porous surface soils 'and porous, alluvial and all existing fill soils not, removed by grading ~-------. ~ WOODWARD· GIZIENSKI & ASSOCIATES CONSULTING lOlL AND FOUNDATION [NGINUIII AND GEOLOGISTS " '.~ -".' @ , . Project No. 72-253 ~age 10 .operations, .be excavated or scarified as required, replaced an~ c;:ompacted -before fi.ll, faatings 'Or slabs-an-grade are con·structed. Over most of the site these materials generally range in depth from 0 to 2ft; however, in the draina:ge channel s they may reach depths 'on the order of 8 ft.' The -fil 1 s appear ta have a maximum thi ckness of 20 ft. Because of the variati ons . in t~ickness 'Of these materials, the.actua1 excavatian and compaction should be controlled in the field by the sail engineer upon visual examination of the exposed soil. {3}' It is recommended that any potentially expansive soils encountered in daylight a'reas, in areas 'Of sha1law cu.t and ·fill or,-where . --. claystane-mudstane materials are exposed at .finish grade in. the deeper cut areas, be. removed to a depth of 2 ft within the entire level lat area' and replaced with properly compacted nonexpansivesoils available on site. Similarily it is recommended that the upper 3 ft of soil tn the' fill areas be composed of nonexpansive soil •. The claysoils may be spread .in the deeper. portion of the fi)ls.· ' .. : ':-.:.'-.' .-.. :.: ..... : .. ~ ".:,:, :.: ...... <' .... , ....... ,. , . . '. . .' . : . . . . ..~ : (4)·It·is recommertded,'tha't'k~ys'for:fills placed {n',the area'. of the claystone-mudstone materials '(Del Mar Formation) and all cut slopes ... be examined by Woadward-Gizienski & Associates·such that actual geologic conditions may be determined. Recommendations far deepening keys or but- . . '. t.ressing may"be presented at that time s~ould this be required •. {5}. A s'et of "Specificatians for Cantro11edFill ll is attached. Recommendations made as-a part of this.repart shall became a part of these specifications. All grading should be observed .and campact~d fill tested by Waadward-Gizienski & Associates. . WOODWARD· GIZIENSKI& ASSOCIATES .' .' , ~- " .... ~,~. "" M. _":""_ ._Ud M. _'®. ; '" ~age 11 Project No., 72-253 .. :e e .. UKIATIONS . The conc1u5ionsand recommendations made in this report are' based on the assumption that the soil conditions do not deviate appreciably fr~ those disclosed bythe'test borings. If variations are encountered during constuction, we s~ou1d be notified so that we may make supplemental recC\""Pendations, lf this should be required. Evaluation· and utilization of soil materials for support of $.t.ructures includes investigat.ion of the subsurface conditions, analysis,' fOr.f.ulation of reconmendatiorts, and inspection during grading. The soil, tn'icHigation is not completed until the soil engineer has been able to ex.a~1ne the, soil in excavations or cut ,slopes so' that he can make, ' , , the necessary 'modifications, if needed. We, emphasize ·the importance: of ~he soil engineer continuing his services th~ough the inspection of grading t incll,.1dingconstruction of fills, and foundation excavations. " " ,':.' . '\ I' "'.''-" ~ . --.z-. . . / " : ,.' .~. 'I: , , , , ' " .. , .' .-. , '. , :. " ", ~ . ~ ~'. .. WOODWARD· GIZIENS'KI & ASSOCIATES '"'. : A,) 1 '.. _en .. ~, __ ~ __ ,un ". "~~.~ --~ ,. .' .. I I \'IS' .,.0 •• ' . ,.~ ...... .. ", • , , ....... \ : ,.,' , ". ....... _:.",.----_ ... ., " . • , . .. .' ... \. , \ .. I "Z.OO I,.., ! .~ , , , , .. • . ~ :. .• ',-,.1---:" ... -----... -.,----. ... -.:~ .. .;. .. -,.~ ..... -. ..:.;-" A~prox. 1500' to E.l Cami no LEGEND: Real , ~ Indicates approximate location of Test Boringo , ...... -_. Indicates ground, surface contours. " ' ~-;l Indicates approximate limits of Del Mar Mudstone, Hard" t:;~ damp, 01 ive-gray si tty to sandy claystones. t=:.~7:1lndicates approximate limits of Recent Alluvium. t:;:;:-;J Porous clayey sand and sandy clayso . 2:2:lndicates approximate location of fa'ult trend. V' .. " ,.,' . " .". , ,> I .,.-'-' I~~ i~dicates ap'~r~ximate limi~s of ~,,~~:,~y~,~, f.ill. 'r---~~~----------------~------~I 81 TE PLAN AND GEOLOGI C MAP RANCHO DEL POND,EROSA . WJOOWARD - G I Z I ENSK I &: ASSOCI ATES CONSULTING SOIL AND FOUNDATION ENGINEERS AND GEOLOGISTS SAN 01 EG:l. CALI FORN I A DR. BY: GS APPROX. SCALE: I" = lIOO' CK'D BY: ft(~J) DATE: s/ls 73 ':.,'" o 5 10 15 20 . 25 28 " . : we = JI DD=.III . Be = ~/9· we = 'fO DO = III-Be =-103/.10" For Legend, see Fi g. 3 Boring ,;.:' .. ,..... Medi urn dense to dense, damp, li ght . . "::~~:, brown s i 1 ty med i um to fine sand (Sot)' 1-:.<~. Very dense, damp, "I i ght brown'silty /' ::'>. fine sand (9<1) with inclusions of gray cl aystone I - v . LOG OF TESTBOR ING I -- " RANCHO DEL PONDEROSA WJOOWARD -GI Zi ENSKI & ASSOCI ATES CONSULTING SOIL AND FOUNDATION· ENGINEERS AND GEOLOGISTS SAN 01 £00. I FORNI .:,-,' :". +I G,) Lf I Q) <J td .... L. ::J (I)' "0 C ::J o L. c::J ]:, o -Q) a:l J: :~':" ,Q) Q 0- 5- 10- , . 13- Boring 2 we = 13 I loose, damp, 1i~t broW'l. silty DD: 1·11 I--) Be = ' 6.... ' :./t;: sard (9.t Porous we = 6 -~~ DO: ~ 2 ~ Hard, damp, brenn sandy clay (CL) Be = flJ/3 n _ ,L::.:, Very dense, damp, 1i ght brenn-gray !:t~f!: silty fine sand (9.t) ._ ;:;':~:$ Very dense, damp, 1 ight gray si lty we = 13 l'l :":." fine, sand (s-i) DD = IOij """"-.:.<:. Be = 80/fl" ' <:'.:/: ~? U1~"~ ~~I:>-.. ,. , .. :;et'"·'··',--·j··"· .:". ,'" '.'!"" . ·we: Water Content in p~rcent of dry, weight. DO = Dry Density in pcf. Be = Number of blows by lijQ-lbo hammer falling .:' 30 inches to d rive sampler 12 Inches. . .- ',,': ,_. ,Sampler Data: ID = 2.0~, 00'= 2.5", ",;,:_~;: ::;.-,:;.: .. ~/~'"::c., . , .' 'OS =, Di rect Shea'r'-"Test ·Data: '. .'. ' " .. , '," . , • .~: ).... .~'. v :-:: , ..... ~ . ': _.= Angle of Apparent Friction-in degrees.' ';:' , :" : , -: ','.' < ,,:',C = ~p.r;arent ·Cohe.sj.o!l',.lp.::,~f.,\,:: .:~.o.",' "",' ': .... '. ' (SM)': Group classification symbol in ,accordance' with the Unified Soil Classification System. -. = Sample Humber LOG OF TEST BORI:NG 2 RANCHO DEL PONDEROSA L-OODWARD -GIZIENSKI & ASSOCIATES CONSULTING SOIL MID FOUNDATION ENGINEERS AND GEOLOGtSTS SAN DIEGO. CALIFORNIA . DR. BY: GS APPROX. SCALE: I" = 5' PROJ NO' 72-253 .·i CK'O BY: KI,i<lOATE: '9/-13/73 F' GIJRE 'NO' , . . . : GJ (J CIS .... '-::::I en "0 c ::::I e ca ~ o GJ G:l .&! +' 0.. GJ 10 0- 5 _ 10 - III-- o - . '.' Boring 3 !8 ~ 9f ...!.. .... qft. fill overlyi.ng this level . BC = 16· : ........ V~ry loosel twnedlum dense, dry silty ... .: fine sand l s.1J Porous . . ~ ~ I~~}~ Hard, d~, brcH1 sandy clay (a.) BC= ~ ~~. . . ~~.:. . . . '.'" ""':'. Very dense, danp, very 1 i ght gray si 1 ty very fi ne sand ($i) we,= III -IJ :%~~:', . gg~k~6"~~)-'~~;------------------------- -: .. . .. \::. .. .Borlng II- 11i::,:{ Very loose, dry si lty fine sand ($i) .. ,." \ Porous. . .. ' . .... {yeri deOse, danp, 1 i gtrt gray-brOWl . ':":f.~\ s i1 ty fine sand (g.{) : ~~{i~~ .. . ,'; T:. " : • :' ~ '.' •• '. '.' :", ' " j • " ~. ~ '.',:, ~ .: '.:'~ .... . ',' , '.:: " .. For legend, see Fi g. 3. LOGS OF TEST BORING 3 & q RANCHO DEL PONDEROSA l-..OODWARD - G 1 Z I ENSK I· & ASSOC I ATES . CONSULTING SOIL AHD FOUNDATION ENGINEERS AND GEOLOGISTS SAN DIEGO. CALIFORNIA ... O .... R'--.;BY..:.: ~Goi-:S ~ .... A~PP~R_OX_ .... S_CA_L_E ... : ... 1 "_=--.5_' -+-... PR .... O",-!J-.-HO..,.· ..... 7.;;;2-... 2-.53;;,.· -i : -. '." CK'O BY: l!?tV DA'TE: 9/13/73 FIGURE ItO-IJ. ~: . 1 :' ., .c +' a. (I) Q o 5 10 13 o .:.···.5'· 8 e . .~. ", For legend, see Fig. 3 e· Bori ng 5 ';'.~":'" loose, dCJllp, brohfl silty fine sand. (S-i) ~':'l." Hard,. damp, brown sandy clay (-CL) . :ra!.: Very dense, danp, light gray silty .' fine sa'ld. ,( S-i) . . .... . . . :f(l;::] . '. ,.: .' ... ' . . , :::i~:l~~ . i.-'::·:~~·: ;~;:\ '::~;~~:'l f~ Boring 6 ~~~{:i Loose, danp, brown si 1 ty fine sand ~;·:X;\; (S~) Pa-ous .' ..' Hard, damp, light brown sandy clay (Cl) ) Very' dense, danp, light gray ·silty fine sand (S-i) , ~ .-, . lOGS OF TEST BORI NGS 5 & 6. RANCHO DR PONDEROSA • i', L-OODWARD - G I Z I ENSK I & ASSOC I ATES . CONSULTING SOIL AND FOUNDATION ENGINEERS AND GEOLOGISTS SAN OIEOO. CALIFORNIA OR. BY: GS APPROX. SCALE: I" = 5' CK'D BY: ./;Ytd DATE: 9 13/73 5 . . ' . I . .. ! • (: , ' 5 8, ." . , " " " ," e "" . , .' For legend, "see Fi g. 3 Bori n9 7 Hard, damp, brown sandy clay "(Ol) , PorQJs ---~-,.... .... -" " " Hard, damp, 1 ight olive-gray silty clay (Oi) .~. . Bori ng 8 , "':.,. ." ... - .-; . ~:M"~ Loose, danp, brMl silty fine sand ::t::i~:i, "Il.,;;;;.Sw1-.:.-::..SC.::.J":....P:...;o:.;.r,;;..ou;;..;s_---, _____ _ , Dense" damp, light brown clayey fine kX/~: sand (Se) ::::: 'v·:·.~ Hard, damp, olive silty clay (CH) ! .. ~.'. : ... :." , '. '--", '. .' -.' . " ' <. , ,. " .... - LO GS 0 F TEST BO R I N as 7 & 8 RANCHO DEL PONDEROSA ~DWARD -GI ZI ENSKI & ASSOCI ATES' " CONSULTING SOIL AHD FOUNDATION ENGINEERS AND GEOLOGISTS SAN D LEGO. CAll FORM I A . DR. BY: GS APPROX. SCALE: i" = 5' PRO", II' 72-253 CK'D BY: O~tI DATE: 9 13 n 6 . I CD (J CIS .... 0- 5- .10 - ; 13-Cf.) '1:l C ::;J o ... c::J X o -cil ..c +' Q. CI) Q 0_ -:·5 - . 10 _ • .' Boring 9 ' (::.:' Loose, danp~ brC7t'«l si Ity fine sand ;·t::.>~~Jg.{) '. ~:~:~,::}. -f'Mi: . Dense, to very dense, damp, light ~~t brO\<f1 -gray • i 1 ty fine sand (a.tJ I Hard, dampt dark gray silty clay (CH) Boring 10 we: 5 ~ ;:::~;~:;~ Loose to med i urn dense, danp, gray-gg;; ~? _ ~l\brCN1 silty to clayey sand (9+S,C) po~o~~:,.-::.,:' .. , we,: 21 ~ 2 ~ Hard, danp, brClr'ln sandy ,clay (a.-Oi). '" ~ :' '.' _ DO -101. I-~ . .' '. " '. . ' . 8C = 1,7 ~ . :. ' .. ". . .,'::' .. ' . ~ ~ ..... '. . ~ . ~ Hard, danp, olive-gray. siltY·~l~y· . '\.:. we =. 17 3 ~ (CL-MH)' DO = 110 ~ .' ,Be= 22 ~~ .' '.' .' .' - For Legend, see Fi g. 3 LOGS OF TEST BORIHGS9 & 10,· RANCHO DEL PONDEROSA' WJODWARD -GIZ1ENSK1& ASsOCIATES CONSULTU4.G SOIL AND FOUNDATION ENGINEERS AND GEOLOGISTS SAN 0 I EeD. CALI FORN IA' . . DR. BY: GS APPROX. SCALE: I" = 5' PROJ. NO.' .121"253 J CK'.D BY: f~d1J DATE: . 9/13/73 . FIGURE NO' 1 ~ , 1 . ! . ;'~-:;:. f;:'· . " ;.., CI) CI) LJ., I CI) U as .... L. ~ (I) "a c ~ 0 L. <::J ~ 0 -CI) ell ,.,c ..... Q. CI) Q ,20- • • Boring ,II Stiff,-damp, light brown silty to fine sandy clay (CL-SC) . . 'Very dense, damp, very 1 ight gray silty to clayey fine sand (s.1-SC) I ·Hard, damp, olive-gray .si lty clay , (Oil wc= 17-~ ,DO = 121-I . Be = 161 t--p..~~ _____ .......-____ _ os: • = 32 C = 17110 25- 0- 28J ~ - Boring 12 ~& ~ 9~ ~~:;~~~:;1~ Very loose, d~, 1 ight gray-brOWl Be = ,l~... ~:;~;}~ si tty fine sa(ld (g~) Porous' WC = 8-'~ ~ Hard, damp, 1 i ght gray-brCWl sandy gg'~ y~ -~ day (el) ," ': Very dense, dampJ' 1 ight gray to" .light bra.-.n silty fine sand (S~), -'1 ~~------------------------- • , '. , ' .: : ~'; .. : For, Legend, see Fi g. 3 LOGS OF TEST BORI NGS II & 12 RANCHO. DE L PONDEROSA W)()OWARD - G I Z I ENSK I & ASSOCI ATES CONSULTI!CG SOIL AHD FOUNDATION ENGINEERS AND GEOLOGrSTS SAN DIEGO. CALIFORHIA ' ' DR. BY: GS APPROX. SCALE: t n = 5' PROJ. NO· 72-'253 CK'D BY: f");.}U DATE: 9/13/73 FIGURE HO· 8 , i I -. r.nRRI ~~ GRAVEL SAND ' , Coarse Fine CoarsJ Med i um Fine 51 LT and CLAY Mesh Opening -ins. Sieve Sizes j I I Hydrometer Analysis I .l :ill-,. , '100 76 3 2, I i 10 16 20 30 IW 60 80 IIW' 200 0 ...". " '\, I\. ,. 90 10' .\. \ .\, \ \ \ 80 , 20' \ --,70 1 30 .,\ I 11-/ ~ L., r \i,..o""" . \ ' \: ,0 c:s \ '\. W Z 60 JI.O~ -1\ '" I-q. .~ '" ~ , . ~ " UJ . 1 " . a:: ~ 50 L\ '\. ~ £5 '\ ' 50 ffi Co) .\ 3-2 . (.,) a:: a:: ~ \ w .\ .1 '\ Q,. -110 -, L 60 . / ., ..r \ ..... ' '. ,.0" .... '\ 00 ' . -". 70 '\ .... "-" .... '\: ...... ....... " "-~ 20 .:--" '" 80 .. ,.." . " ,', .::--.. . r-..... , -10 .. ~ ,90': . -.,.' a 1 100 . 100 50. IO.Q 5.0 .. l.O 0.1 0.05 0.01 0.005 0.001 .. G~I" SIZE IN MilliMETERS SAMPLE CLASS I FICATIOH AND S'tM30L *LL :*PI I -~ Si lty sand (SM) . Non Plastic 3 - 2 . Sand v cl a V (cL) 311-,17 II -I Silty clay (Cl) 39 18 ", *UL = Liquid Limit GRAIN SIZE DISTRIBUTION CURVES ·PI = P1asticity Index "RANCHO DEL PONDEROSA WOODWARD -GIZIENSKI & ASSOCIATES CONSULTING SOil AND FOUNDATION ENGINEERS AND GEOLOGISTS SAN DIEGO, CALIFORNIA " . DR. BY: GS APPROX. SCALE: ..N.A PROJ. NO: 72~253. CK'D BY: t:Z~ DATE: 9/13/73 FIGURE HO: 9 .j } • ..."i;';;;': " " •• .. .~. 1 . • RESULTS OF CONFINEQ COMPRESSION TESTS Initial Final " " ' , , , , Semple Dry Water, ,Dry ~later "lITter Density Content~3.turation Density Content Saturation Pressure +' -e. .-:! -C'\J' .-+' .-C ,- '0 ~ I ~ fa a:: B Ca!llress ion pef % ' % pef % % psf % of I niti~;l Height ' . . ' 3 -I 91 3 8 98-' 20 75 2000 " 7.5' ~ -7 - 2 106 .II 50 109 18 2000 , 2.~ , , 12 -1 93 5 18 99 ' 21 85 2000 5.~ " PRESSURE -psf o 500 1000 1500 2000 -, 5~--~---4--~+----r--~~--~---+----~---r----~--4 6,J---4----4----+---+---1f--+----f------lf----+-----11-----I ; 7~--~--~--~~--~----~--~--~----~--~----~--- RESULTS OF CONFINED COMPRESSION TESTS RANCHO DEL PONDEROSA WC()o..iARD ... G i Z IENSKI & ASSOC I ATES CONSULTING SOl L AHD FOUNDATIOH ENGINEERS AND GEOLOGI STS I ' SA~ DIEGO~,CALIFORHIA • DR. BY: GS APPROX. SCALE: HA PROJ. HO:, 72-.253 j CK'O pj'(:~J;';.!/ DATE: '9./1 3/73 FIGURE NO: 10 '{ ,~: j " • '--..,-,'4" ... :, .. ::.:. ;:.' . , ... ,', . " " " '. ". ' .: .' ,-~.. . ,', TE~T TRENCH CROSS 'SECTION RAt~CHO DEL PONDEROSA ~DWARD-GIZIENSKI & ASSOCIATES CONSULTING SOIL AHD FOUNDATION ENGINEERS AND GEOLOGISTS SAN DIEGO. CALIFORHIA OR. BY: GS APPROX. SCALE: I," = 10' CK'D BY: il?It) DATE: 9 1373 t'