4933 GLENWOOD AVE 2016-01-01 MF Import

� Jordan Construction � JN 00284 July 25, 2000 Page 4 overexcavation and ttie footing width. For example, an overexcavation extending 2 feet below the bottom of a 2-foot-wide footing must be at least 4 feet wide at the base of the excavation. If lean concrete is used, the overexcavation need only extend 6 inches beyond the edges of the footing. An allowable bearing pressure of 2,000 pounds per sauare foot (ps� is appropriate for footings supported on competent, native soil, imported structural fill, or lean mix concrete. A one-third increase in this design bearing pressure may be used when considering short-term wind or seismic loads. For the above design criteria, it is anticipated that the total post-construction settlement of footings founded on competent, native soil, or on structural fili up to 5 feet in thickness, will be about one-half inch, with differentiai settlements on the order of ona inch in a distance of 50 feet along a continuous footing with a uniform load. Lateral loads due to wind or seismic forces may be resisted by friction between the foundation and the bearing soil, or by passive earth pressura acting on the vertical, embedded portions of the foundation. For the latter condition, the foundation must be either poured directly against relatively level, undisturbed soil or be surrounded by level structural fill. We recommend using the following design values for the foundation's resistance to lateral loading: Coefficient of Friction 0.40 Passive EartY. Pressure 350 pcf Where:(I)pct Is pountls per cublc toot,�ntl(il)passlve earth pressure is computed using the equivatent fluid density. If the ground in front of a foundation is loose or slopir,g, the passive earth pressure given above will not be appropriate. We recommend a safety fuctor of at least 1.5 for the foundation's resistance to lateral loading, when using the above design values. SEISMIC CONS/DERATIONS The site is locateci within Seismic Zone 3, as illustrated on Figure No. 16-2 of the 1997 Uniform Building Code (UEC). In accordance with Table 16-J of the 1997 UBC, the site soil profile is best represented by Soil Profile Type S� (Very Dense Soil). The site soils are not subject to seismic liquefaction because of their dense nature and the absence of near-surface groundwater. SLABS-ON-GRADE The building floors may be constructed as slabs-on-grade atop medium-dense, weathered, gravelly sand overlying the dense till. The concrete slab couid be piaced on the existing fill if steps are taken to till up the existing fill soils, re-roll, and compact them according to the recommendations discussed later in the GENERAL EARTHWORK AND STRUCTURAL FILL section of this report. The subgrade soil must be in a firm, non-yielding condition at the time of sl�b construction or underslab fill placement. Any soft areas encountered should be excavated and replaced wth select, imported structural fill. �,� r � GEOTECH CONSULTANTS,INC. S