3121 8TH ST AB 2016-01-01 MF Import

Juncl,2008 Duplex Building L&A Job No. 8A0>5 Page 7 Scismic Iia�card and Ucsign Considcration The T•ugct 5u;:nd region is in an active seismic �one. 'fhe subject site is undcrlain at shallow depth by very-dense Gesh till soils of high shcar strengih. The site is mostly gently to moderately sloped. Thcre is a lack of continuous, ex[ensive groundwater table at shallow depth under thc sitc. "I'he combination of the �bove makes it rather unlikely for seismic t;azards, such as liquefaction or soil lateral sprcading, to occur on the site during strong carthquakes. Therefore, the scismic hazard of tlie site should bc also be minimaL Thc proposed duplex building should, however, be designed tu withstand scismic foroes induced by strong carthquaices. Based on ilie soil conditions encountered by the test pits, it is our opinion that Sei�mic Usc Group I and Site Class D should be used in the seismic dcsign of the proposed residences in accordance ��ith tt:e 2003 International 13uilding Code (!BC). SITG PRGPARATION AND GF,NERAL GRADING Site preparation should include clearing and grubbing within construction limits. Surlicial till, topsoil and �veathered soils should be stripped down to very-densc fresh till soils within the building pad of the duplex building, and thc fill, topsoil should be stripped do�*m to medium- dense weathercd soils within thc drivcway. 'fhe exposed ground should be compacled to a non- yiclding state with a vibratory roller compactor and proof-rolled with a fully loaded dump tn�ck or water truck. During construction, stomi runofC �id near-surface perched groundwater, if any, should be intercepted with d�tches or interceptor trench drains, as required, and conveyed into a nearby stomi inlet covered with a fi'tter fabric sock. The filter sock sltould be cleaned periodically to prevent clogging and should be removed after the completion of the construclion �vork. 'Che onsite sur�icial soils contain a high percentage of fines and are sensitive to mois[ure. A layer of clean quarry spa(ls placed over excavated areas and areu of frequent trat'fic may be required to LIU & ASSOCIATCS, INC.