Laserfiche WebLink
ibundalion. lhcrcibrc. thc lill must bc rcmo��cd to;ally and thc cscavation coNinucd to a <br />minimum dcplh of G inchcs bclo�� Ihc contacl of thc till and thc dcnsc nalivc soil. 'I his <br />should bc at appro�imalcly �.� to G Icct bclow thc c�isting ground Ic��cl.'I�hc c�cavation <br />can thcn bc backlillcd with cumpactcd slruclural fill or crushcd rock to thc proposcd <br />lotmdation Ic��cl or thc fowidation can bc redcsigncd tu allo�� for a thickcr concrc�c pad. <br />l hcsc idcas arc discusscd in morc dctail bclo���. <br />Sitc Prcparation and Gr:�Jing Recommendatinns <br />Sitc Clcariny I)cmolition and Rcmoval <br />l�hcrc is mininud sitc cicaring ncccssar�. �fhc li�undatiun sitc is currcnU� ai�crcd ��ith <br />grass and topsoil, which �vill bc rcmuvcd us part ol� thc cxcavalion proccss. \1'c <br />rcconuncnd that any rcmoved matcrial �wt bc rcuscd dirccUy as structural lill. <br />Ovco-cscavatior /Sub¢radc Prcparation <br />'fhc follo��-ins arc rccommcndations fiir ovcr-cxca��ation and subgradc prcpar.uion: <br />L As diuusscd abovc. undocumcnicd �ills of ��ariahlc quality and consistcnc� <br />undcrlic Ihc proposcd foundation sitc. \Vc rccommcnd uvcr-c�cavnlinc .:nd <br />rcmoving soil in thc foundution arca to a mininium dcpth of OS fect bclow thc <br />conlact hch�ccn thc fill and thc nalivc soil, compacling Il�c o��cr-excavatcd <br />subgradc and rcplacing ���ith cotnpacted structural lill or crushcd rock. 'fhis is to <br />minimirc thc putcnti:d for sctllcmcnt and providc unilorm subgr,idc support. <br />?. If thc loundalion is rcdcsigncd lo incrcasc thc thickness of thc fooling Irom d I'cct <br />thick to approximatcly �.5 to G Icct thick, ihc ibwidation arca ,hould hc c�cavatcd <br />as dcscribcd ahovc. all loosc, disturbcd matcrial shoidd hc rcmovcd. and thcn thc <br />ibuting puurcd dircctl�� on thc undisturbed subgradc. <br />3. Subgradc conditions should hc cvaluat�•d by thc gcotcchnical ubscn cr using a'/ <br />inch diamctcr slccl ��robc. <br />Siruclw'al Pill Matcrials and Comnaclion <br />Por impurtcd soil lo hc uscd as gcncral slructural lill. ��c rcrommcnd using a cican. ��cll- <br />graded sand and gravcl such as Gravcl 13orrow. \1�SD0'I'� 9-03.14(I ) or a I'/, inch minus <br />crushcJ rock such as \1'SDOT 9-03.9(3). Crushed l3asc Coursc. as dcscribcd in thc <br />\VSDO"I Stundard Spccilications. <br />In gencral. thc structural fill should bc placcd in cight-inch horizontal lifls and compactcd <br />ta a mininuun of 9i perccnt of ils ma�imum dr�- dcnsity. as dcicrminccl b� tcst mclhod <br />AS'IT1 U 1i�7 (Modilicd Proctor) if thc Gra��cl 13orrow is uscd or by using a'/_ inch <br />diamctcr. 3 �i�ot long probc if thc crushcJ ruck is uscd. 'l�hc procedurc lo achicvc thc <br />spccilicd minimum rrlati��c compactiun Jcpends on ihc sizc and typc of compacling <br />cquipmcnL Ihc numbcr of passcs, lhickncss uf thc la� cr bcing compactcd. and ccrtain soil <br />propertics. 13c�brc lill control can bcgin. thc comp:iction charactcristics of thc fill <br />matcrial must bc dctcnnincd Gom rcprescnlati��c smnplcs of thc structural and drainagc <br />�ill. A sludy of compaclion charactcristics should includc dcicrmination uf optimum and <br />natural moisturc contents of thcsc soils at thc timc of placcmcnt. <br />' NSDO'I' i� thc \1'tishincton Slme DcP�h�»���I o(l�ransn�h:�tion <br />Gcotcdmir.d anA'I�unncl Comultams <br />IT_70lSondim:!!e.RcdmnnJ KJ. S�c 703 1'honr lJ'_SWSG-GSbI <br />\t'oodim Jlc. \1'n 9NnT 1'agc J fac (J25 � 4AS-2(a,U <br />