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Gcot�chnici�l Gnginecring E�n�uation <br /> 8310 Rim Drivc- Ryan <br /> Novemhcr R, 2004 <br /> Rlvlt filc No. 21 GOd <br /> Pagc 10 <br /> resislance acling on the bclo���-grade portion of thc loundation. Recommendatious (br frictionnl and <br /> passivc resistance to later.�l loads are presented in thc Foundations subscction ef this reporl <br /> Pcrnianent drainage systems should be instalicd for rctaining �,��alls (and subsurfnce ��alls). Nc <br /> rccoiiimend that these urninagc systems consist of an 18-inch �viJe zonc of dcan (less than 3 percent <br /> fines), frcadrnining granular mnterial placed along the back of the �sall. Pca grnve� is an ncceptaMe drain <br /> matcrial, or drainngc compusitc may bc uscd iu;tend. �1'c recommend thF�t wc he rztained to e��aluate thc <br /> proposed wall drain bnckfill matcrinl for its suitability. <br /> 'I'hc granulur matcrial should hc placcd up the back of thc �vall to within I foot of thc ground surf�c:. <br /> 'I'he top I-foot should 6c a Inycr of compacted, low-pernieability soil ro limit surface wnter infiltmtion <br /> and should be separated from the underlying �rce-druining material by a layer of plastic shceting or <br /> building paper. A rigid per(orvtcd or slnttcd PVC dra��ipipe, iitiving a minimum diameter of 4 inchcs, <br /> should be cmbeddcd in pci� gra��cl or somc other frcc-o,nining mutcrial and wrappcd in a non-o�oven <br /> liltcr fabric such as Miridi 140NS1_ at thc bnsc of thc wall along i!s cntirc �en�th. 'I�his dninpipc should <br /> discharge inlo tightlines Ieading to an npproprinte collection and disch�rg� puinL Surface water drains <br /> and mof dr.�ins should not be connected to �call nr footing drain, until tliere is at Ieast ! foot of elevntion <br /> diflcrcrcc belo�e ihc footing dr�ins. <br /> �VI �v�ll hnck�ill shi�uld bc �voll compactcd as outlincd in tltc Siruclural Fill subsection of ihis rcport. <br /> Care should he �aken tu prevent the buildup of c�cess lateral snil pressures, due to overcompaction of thc <br /> wall backfill. �'his can bc nccomplishcd b� placing ��,�u n���:rn in 8-inch thick loose lifis mid <br /> compacting it with small hand-operatcd cnntpnctors ��'ithin a distancc bchinJ �hc ��all cqunl to at Icast <br /> one-half dic hcigl�i of thc ��all. <br /> I)ischargc uf Runoff <br /> CurrenUy dischargc from the c�isting rooPs on thc housc and garage arc Icd to the edge of ihc slopc and <br /> aliowcd to Ilmr don n thc slopc. This siioidd bc chmiged ns follo�cs: <br /> ,,. Runofl�;�roiu the guttcrs surroundine thc roof of the house and garage �vill be Ied ihrough <br /> Ju��nspow, to catch hasins or cicanouts and by tighdinc pipe to a cntch basin Icading to <br /> RMI Associates, Ltd. <br />