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Mr. James Gallo�vay <br />— Scpteiiiber G, 201 1 <br />'The project siEe is not mapped as a seisn�icJliquefaction hazard on either of the above referenced docun�ents. <br />Based on the results o1'our study. 1[I Ol]I' 0��1111(lil, there is no risk 1�or soil liquefaction to occur at Ihis site. <br />F3a�e:d on soiI condiiioiis observed at tl�e �ite and otir lcno�vle;d�e of ille area ceolo�y, per Cl�apter 16 of� tl�e 2009 <br />International Building Code (1BC'); site e1�ss "C� shouId be used in ,U�uctural design. Rased on this site cl�ss, in <br />�3ecordance "'iih t1�e 20()9 [I3t', tlie following parameters should be tised in computin� ;cismic forces: <br />Sersntic Desig�r Purr,rnerer,ti� (IBC 2009) <br />Spectral respt�ilse accelet-aiion (Shc,rt Peri��d), S,,,; 1.247 <br />Spcctral response acceleration (] - Sc�<�nd Period}, 5,,,� 0.(�02 <br />[�ive percent damped .2 sccond }�erio�i, S�� O.S32 <br />[� i� e pei�cent damped 1.0 seeond E�eric�d, S1,� — U.401 <br />Values detern�ined using thc; iJnited States Geological Su�ti�ey (tISGS) Groiind \lotioit Parameter Calculalor <br />accessed oil September 6. ZO 1 1 at the ���eb site http:/icarthc�uake.us��s.<�ov; researchiha-r.,ma�s/desia��Iindex.ph� <br />Slope Stabilitv <br />Cliapter 37 of� the Eh1C, catecori-r_es slopcs witli �,radients in excess of 40 percent as a landslide l�azar•d area. Tlie <br />code reqtlires that developt7ieiits adjacent the c�•est and/or toe ofa iaiidslide llazard area ha�e tfie setback buffer <br />establisheci in ac;cordance �aith standards contained in Chapter 1� of the h�tertlational Buildin� C:ode ([BC}, or as <br />tl�e IBC' i� u�dated and amended. I�I�e code allo�-� I��r setback I�ul�ters t}lal are less tllan those o�icained by <br />application oF the 1BC st�l11C{�1CCI5 provided it can be dcnic�nstrated the reduced buf�fer5 adequa�ely mitigate the <br />h�zard. <br />l�o c��aluatc ti�e irnpact ot� il�c plannc;d develc���ment �in the stahility of the south slope, we �ompleted stability <br />anal}�scs usin,� th� coiilputcr protrarz� WI1��S�I���I�L on a slope cross-scction as sli<��vn ��n I'i�Jtire l. �The analyses <br />�ere perfc�rrticd 1<�r ctisling and potit-c;c�nstruetioti �onditions. Con�iderins� iha� thc autaelave addition �vill be <br />sup�orted on a siructtiral sl��b, we m�deled thc; loading i�rlposcd as a uniti�rm sti�ess �qtiivaleiit to �}00 pounds per <br />syuare tnt�t (pst) over the entire ���idtkl ot llle additiori. �I�his stre�s irlcltides t11e equip�►ient ����ight and Ille <br />estimated ��eigllt of the slab and building. T�}ie post-constr-uction analvses also inciude pseudostatic or seismic <br />analysis using a llorizontal acceEeration value af� 0.17g to sin�ulate laadiiib durii7g a seismic evenE. The follo�+�in�� <br />tai�les summai�ize the i-esults ot�the analvses listin�� tlie 5afety factors for the �ritical failure surfaces generated b_y <br />the analyses. <br />I�he results of aur analyses demonslrate that loading eonditions impc�sed cm the siope by the addition �vill ha��e no <br />adverse impact on the slop� stabiiity. Slope stabiiity calculation sumniaries are included in Appciidix A. <br />F'roject No. "1�-547I -2 <br />. Page 1� o. 3 <br />