1718 ENGLAND AVE 2016-01-01 MF Import

� Gcotcchnical Engincering Fvaluation EoalanJ Avenuc Lot � Junc 2, 2005 NGA Filc No.411805 Page 5 � Landslidc Hazard/Slopc Stability The criteria used for evalualion of IandsliJe hazards include soil typc, slope gradicnt, and groundwater Iconditions. A stcep north-facing slope with a gradicnt of up to approximately 50 degrces (I 19 percent) is located below the planned building arua. Preliminary plans indicate that much of this steep secticn of thc � slope will bc removed during grading for the driveway and residence. We did not observe evidence of significant slope instability during our im�estiaation, such as deep-seated landsliding. �Ve did not observe � scepage or significant crosion on thc slopes. I Our explorations indicate that the core of the steep slope consists primarily of inedium dense to very Jense sand. Inclin:uions of up to 5�)degrees on the slopc indicate high strength and internal friction angle I within the undcrlying, umveathc�nd soils. Rclatively sh:illow failures as well as surficial crosion are nawral proccsscs and should bc expccted on thcsc slopes. It is our opinion diat whilc therc is potential ibr crosion, soil crecp, and shallow failures within thc loosc surficial soils on the stcep slopc; thcn; is not a ( significant potential for decp-scated slope failure imder current site conditions. Proper site grading and drainagc as rccommcndcd in lhis report should help maint;�in current st;�bility conditions. I CONCLUSIONS AND R�COMNIGNDATIONS I Gencral t It is our opinion that from a gcotcchnic,d standpoint thc sitc is compatiblc with thc planned dcvclopmcnt. ( Our cxplorations indicated Ihat compclent sand dcposits underlie the sitc. These native soils should providc adcquatc support for the planncd foundations, slabs-on-grade, and pavemcnt. The residence could be supported on conventional spread footings, provideJ that the foimdation eacavations are ad��anced through any ropsoil or loose materinl and extended into meu. im dense or better native soils. We nnticipate that retaining/shoring walls will be used to support cuts and (ills for this project, however, I grading plans had not bcen completcd at the time this a;port w:�, �rznared. Preliminary pl:ms indicate that cuts up to 2S fee[ below the current grade .ve anticipated for the daylight b�sement of the proposed residencc. We have provided gencral recommendations for tcmporary gradina on the site and general design paramcters for rctaining walls. �Ve are a��ailablc to providc spccific retainina wall/shoring rccommcnJ:uions:�s thc projcct plans dcvelop. I NELSON GEOTECHNICAL ASSOClATES, INC. I