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Subsurfacc Exploration, Geoingic Hanrd, and <br />Belvedrre :.ors Easr Preliminary Georechnical Enginerring Repon <br />Evereu Wnsdingmn Grologic Ha�ards and Mitigatiou <br />For th <br />. .. ... i " ___ .___� �_._�. TL.. <br />top of the slope is depicted on the Site and Exploration PI , Figure 2. Based on our anaiys�s, <br />we recommend that buildings be sited at or behind the to slope; however, special <br />foundation design criteria are recommended to mitigate landslide hazards where construction of <br />structures is planned within 40 feet o( the top of Ihe slope. Specifically, our analysis indicates <br />that under static conditions, theoretical failure sur(aces with (actors of safety of less than I.5 <br />could extend up to approximately 20 feet past the rop of the slope. Under seismic conditions, <br />theoretical failure surfaces associated with factors of safety less than 1.1 were calculated up to <br />approximately 40 feet back from the top of thc steep slope. The risk of damage to the <br />proposed strucmres by seismically induced landsliding is low, provided the recommendations <br />contained in this repon are properly followed. Our analysis also indicates tttat duwnslope <br />movement associated with landsliding under the design seismic conditions is relatively small <br />(approximately 0.5 inches or less) up to within approximately 20 feet from the top oi the slope. <br />Dased on these resul!s different foundation design criteria are recommended depending upon <br />building location rel;�tive to the top of the slopc. Pecommended landslide hazard mitigation, <br />based on building location relative to the top of the slope, is summarized below in Table 2. <br />Table 2 <br />Summary of Recommended L.andslide Hazard 119itigation <br />Specific recommendations regarding these options for mitigation are provided in the <br />Foundntrnns section of :his report. <br />7A I:KOSION HA7_ARDS AND D11T�IGATIONS <br />'I'he nativc sedimcnts underlying the site contain a high percentage of si:t and fine sand and arc <br />hichly scnsitive to erosion, particularly in sloping areas of the site. In order to control erosion <br />and reduce the amount o( sediment transport off the site during consvuction, the following <br />reaimmend:uions shnuld he fnlluu'ed. <br />,51�vr�h 5. '(Kw -� .1SSOCUTED E�RTH SGENCES. INC. <br />����,� �������„�, �-.,,,,.„u,�„i,,���k,. H:A Page8 <br />