2507 HOWARD AVE 2016-01-01 MF Import

Geotechnical Gn�:inccring Rep,n� I lausing Flope December 5, 200�3 RMI Pitc No.21704 Pagc 12 "Iliese recammended lateral earlh pressures fer levcl backfill are based on the assumption of a horizontnl ground surface adjacen[ to the wall for a distance o�at Icast the subsur��ace height of the wall, and do not accoun[ for surcharges. Additional lateral earth pressures ,hould be considercd for surchargc loads acting adjacen[to subsurface walls und within a distanee equal ro the subsurface height of die wall. This woidd include the effects of surcharges such as traCfic loads, iloor slab loads, slopcs or o[her sur�acc loads. Surcharge effects should bc considered, if appropriate. l'hc latcral pressures on walls ma)' be resisted by frictiun behvicen thc foundation and subgradc soil, and by passive resistance ac[ing on [he below-gr�de portion of the founda[ion. Recammendations for frictional and passive resistance to lateral louds are presented in the Fo�mdations subsection of this report. All �vall backlill should be well compac�ed as outlined in thc Structural Fill subsection of this report. Care should be taken to prevent the buildup oF excess lateral soil pressures, due to overcompaction of Ihe wall backfill. This can be accomplished by placing wall backfill in 8-inch loose IiRs and compnc[ing i[ with sntall, hand-operated compactors within a distance behind the wall cyual to at less[one-half tLo height of the wall. Permanent drainage systems should Uc installed for retaining �valls. We recommend t:iat these drainage systems consist of an 18-inch-�vide zone of clean (less than 3 percent fines), free- draining granular material placed along the back of the walls. Pea gravel is an acceptable drain material, or drainage composite may be used instead. We recommend that we be retained to evaluate the proposcd wall drain backtill material for i[s suitability. T hc eranular material should be placed up the back of the wall to widiin I foot of[he growid surface. The top 1-foot should be a layer of compacted, low permeability soil to limit surface «atcr infiltra[ian and should 6e separated from the underlying free-draining material b;,a laycr ol' vi;quecn or building papec A rigid, perforated or slotted PVC drainpipe, having a minimum diameter oC 4 inches, should be embedded in pea gr;ivel or some other free-d:aining material wrapped in tiller fabric at the base uf die w..��, a�o:.,, its entim leneth. This drainpipe should RMI ASSOCIATES, LTD. ,��::- c�x:,a :• - - — , ,� — - w.. � :� �.::�'�� ,