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Home My WebLink About; Wilson Apartment Building; Soils Report; 1965-11-08II:\\l?IOXI) S0II.S E\GIxl~:F:RLNG ilr,/, U,hl.+~ (,,, ,.~ ,I,,I’i.,i*. n.. 101..:,*1 o., ,.L,Y/i r;t, COI.TtiOL 199 N, STATE COLLEGE BLVD, . ORANGE. CALIFOF1NIA November a, 1366 Job No. F65-151 SOIL STUDY Apartment building site located on the west side of Jefferson Avenue approximately 400 feet north of Euena Vista City of Carlsbad, California Owner: Mr. El Dean Wilson Introduction This report presents the results and recommendations of a soils study for the purpose of designing satisfactory foundations for the proposed three apartment buildings, each containing four units 0 Eearing values and settlement analysis will be presented in this report as well as recommendations for light grading operations to prepare the bullding pads and parking areas. Investigation Four borings or excavations were made over tne site in the proposed building areas for the purpose of classlfylng the -?ertIner.t fojndatlon soils as well as obtaining botn dis- turbjed and undisturbed samples for lsboratorg testing. The property faces a lagoon and has terraced slopes from about 2C$ to 3% moving downward towards thtlt wstnr on the west side of the property. The natural sed1:ner;t.s sre dascrited as Inter- bedded brown silty fine to medium sands an3 t,an and reddlah- brown sandstons with some dlalrtegrated granite. Tne facesof the existing terraces are quite loose due to weatherin,;: and insect boring, however stntle undlsturtsd sol1 was encour>tered at a depth of from one to tno feet. The moisture content of trie near surface soils was quite dry with a slight Increase noted with depth. The results of dlreot shear teets perf,>rmed on remol,led saturated samples of the typical tcarlnl; soil resulted in an angle of internal frlctlon of 320 with 120 p=s.f. allowable cohesion. The following table preser,ts the results of tile direct shear tests: tl4~lSloSI) SOI1.S ~s(.I\lc~I~IscG rRiL,M~h*il .,O,L, ,*.i5.~lilT,l:Y”. G”,~., .rto\ ,.,,I, 7,” CONTIOL I: Job No, F65-151 199 N STATE COLLEG BLYD, . ORANGE, CILlFORNi.4 November 8, 1965 -2- Water Content Normals Peak Shear Ultimate Shear Stress! 3tress Strain Stress Strain Natural Test Sample 6) (%) ( A-l 9-l 14.2 A-2 9,l 12.6 Bearing capacity baaed Terzaghi formula Is: t.sof.) (t.s.f,)[lnches) (t.s.f.)(inches) 0.6 ~ 0.50 -42 1,6 ~ l"O9 ::2 1.04 :E% on these values and caloulated by the Y = CN,~ + wDfNq + aEN, = 100[20) + 100(l) 18 + lOO(O.5) 16 = ZOOI) -f- 1800 -t- 000 = 4600 p.8.f. ultirmte) qa = 1506 p.s.f. (allowable for either square or continuous footlncs~placed at least 3.2 inches Into undisturbed natural ground oriaporoved compacted fill). Maximum density determination 1 were made on the typical native soil according to the A.A.E.H.1. Stenlari Test Method TltiO-57 modified to use 3 layers in lieu of 5, Soil A Prawn silty flnr: to coarse sad wit:; some sandstone fra,-ments and clly tln:!er; maxLr.um density 121.5 lts,,/cu.ft. at iJ-S$ optimum inolst.ire, An expansion t,,st was performed on a rerolded sample of this mtive soil an3 It coroacted to 93' ,. and unler optimum mols- turc usin:: a conflnln; lsad of 650 p,s,f, Ar expansion of 2*C$ !vas recorded lndloatlng that the natlvo soils are slightly expansive with respect to seasonal volume change, however with the heavier structural loads lrvclved, no problem is antici- pated as a result of seasowl vol.lme charge of the soils. A consolidation test was performed on an wdiatllrbed sample of the underlying natural ground which would be In the vlclnlty of the proposed foundations. Porous stone8 were placed at the top and bottom of each sample which permltted the free flow of water l!;to and from the soil during the test, Successive load Increments were applied to the top of t,he specimen by R lever-arm mechanism and progressive anr? final settlement under each 1ncremer.t was measured to an IIA\l\lOSI) 5OlI.S I~:.\(:IsKIIRLsC .: ../ *1 ,~-*, ,Fd/ ,UM,i.lil. (.r:L.i ,h.LSf in. ,o., io:,.,: a:,?., s,L:I L5 WiL <“-ilrlOL Job No, F65-151 199 N STATE COLLEGE BLVD . ORANGE. CALIFORNIA November 8, 1965 -;:- accuracy of .OOOl inches. The final settlements so obtained were plotted on semi-logarithmic graph paper and the results are shown graphically on figure 1. Settlement calculations lndlcete that under structural loads of 1500 p.9.f. a maximum ssttlemer,t of 2,O inches could occur if the foundatlors were placed In the loose top soil, Provided all of these loose soils are removed and tho footings are em- bedded at least 18 lcches lnto undisturbed natural ground or ap;,roved compacted fill, pest-construction differential settle- mer.t will be or the order of l/2 inch or less which 1s within design tolerances, Foundation Fiscomendatiors A safe Rllowakle sol1 bearIn pressure of 1500 p.3.f. has been d~etermlnnd wit,: a fa ,tor of safety of at Icast 3 against local or general shefir fallurl, Settlepent 7 ur,:!cr t,:ese loads with the proper gradlLng procedures, will be of no przylem for t:le type of structurps planned, namely one and ta0 story apartment builidlrq?. The Erading operqtlon shoul;l be corlducti:d in the f'ollowlng monnnr. The site nt t?e ?reser.t tllno 1; s terraced slope with some light v?gPtntion and looue surface soils. For the building arens, all of thl:l vegrtatlon should be stripped from the ground surface ar.d all of th e loose soil should be removed to expose firm undisturbed natural ground. If com- pacted fills are needed to raise the building pad to the desired fln.sl elevation, they should ke placei? In the following manner. Native soils may be tised for fill purposes provided they are free from vegetation and deleterious substances. They should be spread In thin lifts of 6 to e inches, watered and mixed to near optimum n:olsture and thoroughly compaoted to a minimum of SC@ rePatlve compaction by sheepsfoot rolling or pneumatic-wheel rolling. Maximum density determlnatlona for the fill soils should be In accordance with the A.A.S.H.O. Standard Test Vethod T180-57 (25 tloas on each of Z layera with a 10 lb. hammer falling 18 inches in a mold of l/30 cu. ft. volume). Most of the bulldings will have wood floors, however for the limited floor slabs involved It 1s recommended that 6x6/10x10 woven wire mesh be used and a polyethylene membrane be placed II,\ 11 \IOS I) so I I.\ 1,: \(;I SEER1 SG l~/*/~,IM,hll/” so:tr. ,N,iS1~Cl.,OV. iiillh_L>*i:o., s,,::,,ii Job No, F65-151 199 N STATE COLLEGE q LVD~ . ORANGE. CALIFORNIA November @# 1955 -4- beneath the slab to act as a moisture barrier. Garage slabs are not included in this recommendation, however good compaction should be achieved beneath all garage slab areas and if any utility trenches are involved beneath any slabs, they should be properly backfilled and compacted with clean soil. Respectfully submlttcd, HAMMOND SOILS ENGINEERING BY RH:mh Distribution: a-Mr. El Dean Wilson 2-C~ity of Cerlsbsd Building Dept. Revlewed by e I 1 1 r f i t d i 8 ’ ,$ . I j II ?\l\!sl\I) :5liil.‘~ ! \ , I -. 1,~ ! I ; ! ', 1 -ab.nY_*,-/l?l U..v-*Wm.rm..m 096 .94 .92 -90 .a0 .86 ,.. 025 0.5 I 2 4 0 I6 Pressure Tons/sqft .6 .0 ! 2 c 6 R 10 23 Pressure Tonr/spti ProicCf Apartment buildinn site _-_.- ;licnt El Dean Wilson 3or/Sample No. i/l IoePm-me* 1,5’ -'L-' 11/8/65 ---j CONSOLIDATION TEST- PRESSURE CURVES 5 FIGURE I HAMMOND SOILS ENGINL. .rNG 199 No. State College Blvd. Orange, California PH: 633-5610 I- :* ,c, “, ---.. I-... ‘.-. .~. ..~ A I: .\. i/’ /\it I,‘:. , i jY ;,~ ;;,1- J.k ; ,~;:.I.: r~, AL, ,~ ,: ,‘7 /__. ! L.::,, ,,_’ F. , ,L-=” ,,‘a: : ,I, /:,:-. A i : ‘. ., ! ,. <‘_ i,,L !~ I : ;:\.i. ‘. __‘. r- Lf~ *k~tli. -- -.--~-- % ic;,,7 ! ,.!l ‘~. * v ‘,L. ‘. ..~ ~~- ri ,,’ ! ,~‘L._.