Shallow foundations consisting of strip footings or a perimeter turndown foundation are considered suitable for support of the proposed building and the adjacent 10-ft diameter raw water tank. Footings should be founded in competent residuum of Strata B2 and C; or on new Compacted Structural Fill. A design bearing pressure of 3,000 PSF (net allowable soil bearing pressure) is recommended for the footing design. Note the recommended bearing pressure may be increased by 33 percent for wind and seismic loads only when used in conjunction with load combinations defined in IBC Section 1605.3.2, Alternate Basic Load Combinations for use with allowable stress design or other applicable code exceptions. For conventional strip footings and turndowns, minimum footing widths of 16 inches and 12 inches, respectively, should be maintained for shear considerations. This bearing pressure provides a factor of safety of at least 3.0 against general shear failure. Compacted structural fill should meet the requirements outlined in Section 6.1.2 for Compacted Structural Fill...
