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IGcotcchnical Gnginecring L'•valuation <br /> 1625 Gn�land Avcnuc <br /> I Gvcrctt, \Vashington <br /> NGA filc No. 781G08 <br /> I�cbruaq�20, 2008 <br /> Pngc 4 <br /> IThc core of thc sitc slopc is infcrccd to consist of competcnt granular soil deposits. It is our opinion that <br /> I thcrc is not a significnnt potential for decp-scatcd slopc failures undcr currcnt sitc conditions. Rclntively <br /> shallow sloughing failures and crosion arc natural proccsses and should be expected on qie stecp slopc. <br /> Ilo�vcvcr, thcsc proccsscs could bc limitcd tl�rough thc maintcimncc of vcgetation on thc slopc and <br /> Iappropriate drainage systems. Proper sitc grading and drainagc as well as vegetation managcmcnt as <br /> rcconunendcd in this rcport should hclp maintain currcnt stability conditions. <br /> IScismic Hazard <br /> I \Vc revic�ved the 200G Intcrnational Duilding Codc (Ik3C) for scismic site dassification for this project. <br /> Sincc mcdium dcnse eranular soils were gcncrally cncountereJ midcrlying thc site at depth, thc sitc <br /> Iconditions bcst lit tl�c 113C dcscription for Sitc Class D. <br /> I liazards associatcd ���ith scismic activity includc liqucl�iclion potential and amplilication of ground <br /> motion by soli deposits. Liqucfaction is causcd by a rise in porc pressures in a loosc, fine sand dcposit <br /> bcncalh thc ground�vatcr table. It is our opinion that the competcnt gramdar soils inteq�reted to undcrlie <br /> ( thc sitc havc a lo�v potcntial for liqucfaction or mnplification of gromid motion. <br /> IThe competent granular soils inlerprcted ro form the corc of tlic site slopcs are considcrcd stable �viili <br /> respcct to dccp-scatcd slopc failures. liowcvcr, loosc surficial matcrials on tlic slopcs havc thc potcntinl <br /> � for shallow sloughing failures during scismic c�cnts. Tliis sliould no! affcct tlic planncd residcncc as loug <br /> as aIl of thc rccommendations presented o\in this report arc followcd. <br /> CONCLUSIONS AND RGC011�1MC;VllATIONS <br /> Gencral <br /> It is our opinion that �rom a ��cotcchnical standpoint thc sitc is compatible with devclopment as a <br /> residential lot, provided that our recommendations arc incorporated into tlte dcsign and construction of <br /> tliis projcct. Thc site slopc is wnsidcred slnblc �vith respect to dccp-scated failures. �Ve have provided <br /> rccommendations fur foundation embcdmcnt near thc slopc to Iesscn the impacts of the proposed <br /> devclopmcnt on thc slopc and to nlso rcducc the impacts of any potential slopc failures on thc structurc. <br /> Our subsurface c�plorations within thc site genenlly csposed medium dense or bettcr native sand. The <br /> mcdium dense or bctter nativc soils should provide adcquatc support for the planned residence. Ne <br /> I <br /> NELSON GEOTECHN/CAL ASSOC/ATES, /NC. <br /> I N� <br />