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� <br />I <br />' <br />� <br />' <br />I <br />� <br />1 <br />January 22,2003 <br />I I W A Projeet Nu. 200L I R i <br />( without documcnt�tion of thc tiU placrmcnt .uid sur�cy dat:i Ihruuch timc sho�cing <br />consolidation progress. We undcrsland lhal Ihc silc ��;is rc,�ra�ird �•ia a bal;uicrd cul and <br />fill in June 2002. BascJ on lhc Cbnccptuul Gradiiig Plan by 1'riad Associalcs. stanipcd <br />5/I C/02. lhe cuts at thc cun•ently pre�puscd huilding p;id �ccrc lo bc un thc ordrr of I to ? <br />IeM ul lhc r,isl buildin� aiJ and 2.5 tu -! Icct ilI Illl' 1l'l'tiI l'111I. I IIL lIl'lfl'L' O� <br />preconsolidation (prcloading) gaincd bj� rcmo��al uf this till is unknown, duc tu thc lar.k <br />ofdocwnentation of till placa�mcnt. �4ithout Ihis intirrmation. hmcc�cr, and in <br />considcration of thc conditions rc��calcd in our borin��s, il is prudcnt to c.epcct turthcr <br />consulidation of lhe clay due �c� thc �eci�ht of the cxisting o� crlying lill, as such clays can <br />t.ikc many ycars lo consulida(c undcr IoaJ. If thc ci.ry nc�ually is in cquilibrium ��•ilh thc <br />present loads (c.g. lhe fill abovc il), turthcr cunsolidation sculcmcnl of a minimum of'/•_ <br />to I%: inchcs would be erpcctcd tu occur Juc to lhc ncl incrcasr i,fa I OU pst� Iluur load. <br />This rangc of valucs is bascd on thc assumption that a cuncrctr Iluor slab �eould bc <br />placcd �t�itii no nct incrcasc in dc�,rtiun uvcr prescnl ��radcs. Scl(Icmcnt ���ould alsu occur <br />d' f'f <br />I� <br />I <br />' <br />� <br />� <br />I■ <br />� <br />i crcnt�ally, and could bc up �u Ihc lolal anwunt ofsctUrmcnt. <br />Liyucliabic �uils wcrc cncuuntcrcd bcnccith Ihc d�iy in BI I-I, and ahu�c il in GCI'x <br />borings. Scismic liyucfaction of thc f31 I-I soils hcheccn Zti and 3 i icct is cstimalcJ tu br <br />accompanied by about a 5-percent vulumMric sU:iin, which �� utdd cause sclticmcnt on <br />thc ordcr ol'2 to 3 inchcs. 'I'hc cstcnt, lhickncss, .III(I (Il'�71I1 U���1li1CIllI:IIIy III�UI`I18IlIl' SOIIS <br />is expectcd to b� highly variablc m;d, lhcr�tiire, sc�llcment liont liyuclaction cl�iccts <br />would be dit%rclttial, causinl damagc lo struc�ures supportcd on sh,illuw Iuotin� <br />foundations and'concrcte slabs on �radc. � <br />In vie��� of thc high priibability of aJ��erse settlement eflccts on the propuscd su�ucture, <br />undcr bolh slalic an� scismic li�ading conJilions, wc rec�immcnd Ihat thc Iluur sL•ib and <br />lhe slnictur<d clemcnts ofthe shop building bc suppoiicJ oii piles. Such piles should bc <br />designed lo resist soil downdrag loadiug duc to potcnti�d srulcmcnt cf(ccts. <br />'I'hc I'ollowing scclions prescnt gcotcchnical rccunm�cndations li,r dcsign and <br />construction of Uic proposcd devclopmcnt. <br />1'll.� FOUNUA9'IUNS <br />Although drivcn pilc systems, cotuprisin� timbcr, concrctc, ur slcd scctiuiu, would bc <br />feasible, we recoi»mend lhat the piles should consist of concret� au�crcasl j�iles <br />extending into dense lo very dense native soils (encounlered below upproximatcly 30 to <br />35 fceQ, as indicated on lhe boring Iogs and dcpictcd ou I'igurc 3. f3ascd on thc cs�icctcd <br />building loads, which wc undcrstand may bc of the ordcr uf I� to 2U luns per column, <br />each coluntu could bc supportcJ by a singlc augcroast pilc. <br />The allowable capacily ofauger-cast concrete piles ���ill vary �vith pile Ieng(hs and <br />diatnctec Tliey typically range in size lirnn 13 �0 2� inches in diametcr, at Iengths up to <br />about 60 teet. Thc length of individual pilcs can be varicd �eithin thc capabilitics of thc <br />drilling cquipment. <br />2UO2-13t Suppl LR.doc i II\CA Gci,ticirnccs Inc. <br />r3 <br />