2710 VIEWCREST AVE 2016-01-01 MF Import

Thomas Kelly JN 95192 June 7, 1995 Page 3 � department states that it may be able to authorize slope buffer width averaging. The buffer may be decreased to 12.5 feet, if the buffer being increased in width lias similar or better vegetation than the bu(fer being decreased in width. The city also requires adequate protection for Powder Mill Gulch and a geotechnical engineering study that addresses the requirements of the Sensitive Areas Ordinance. As indicated on the test pit logs, the soils at the house site consist of fine- to medium- grained sands. These sands are loose to medium-dense. Sands are hfghly erodible, but they are not susceptible to deep sliding. If adequate erosion protection is provided and suHace water is properly disposed of, it is our opinion that the buHer can be reduced to a • minimum of 15 feet from the edge of the steep slope. We do not recommend placing fill on the slope, and any disturbed areas should be revegetated with native vegetation. The house may be supported on conventional foundations on the sands underlying ihe topsoil. We recommend wetting and recompact:ng the sands in footing trenches, as they are relatively loose. Footings should be founded a minimum of 2.5 feet below the existing ground surface. Eottv�nS�iaa�LF�undations The proposed structure can be supported on conventional continuous and spread footings bearing on undisturbed, native sand soils, or on structural fill placed above these competent, native soils. See the later sub-section entitled Gengr�L��rShx�Qf.k and $1[llCs�[�LF,II for recommandations regarding the placement and compaction of structural fill beneath structures. We recommend that continuous and individual spreud footir.gs have minimum widths of 16 and 24 inches, respectivety. They should be bottomed at least 12 inches below the lowest adJacent finish ground surface for frost prutectlon. The local building codes should be reviewed to determine if different footing widths or embedment depths are required. The footing may be designed for an allowable bearing pressure of 2,000 pounds per square foot (ps�. A one-third increase in this design bearing pressure may be used when considering short-term wind or seismic loads. Lateral ;oads due to wind or seismic forces may be resisted by friction between the founda- tions and the bear(ng sofis, or by passive earth pressure acting on the vertical, embedded portions of the foundations. For the latter condition, the foundations must be either poured directly against relatively level, undisturbed soil, or s�rrounded by level structural fill. We recommend usfng the following design values for the foundation's resistance to lateral load:ng: GfO'IliCll('ONtiUI:DAN'IS,Wt'.