1136 GRAND AVE A&B 2016-01-01 MF Import

( � April 23, 2007 Mr. Scott Andcrson L&A Job No. GA126 Page 9 2,500 psf for footings poured on structural fill constructed on these competent basal soils. 'I'he footing bearing sc.ils should be verificd on-site by a geotechnical engineer after the footing trenches havc becn cxcavated and beforc the footings arc poured. • The minimum depth to bottom of perimeter footings below adjacenl final exterior grade should bc no Iess than I S inches. 'Che minimum depth to bottom of the interior footings bclow top of floor slab should bc no Icss than 12 inches. • The minimum width should bc no Icss than 16 inchcs for continuous footings, and no Icss than 24 inches f'or individuul footings, exccpt those footings supporting light-weight porches and wood deck. A one-third increase in the abovc rccommended allowable soil bearing pressure may bc used �vhen considering short-term, transitory,wind or seismic loads. Por footing foundations designed and consweted per recommendations above, we estimate that the maximum total post- construction settlement of the duplcx building should be 3/4 inch ot Icss and the differential settlement across building��idth should be 1/2 inch or Icss. Lateral loads on buildings can bc resisled by the friction force betwecn the foundations and the subgrade soils or the passive earth pressure acting on the below-grade portion of the foundations. �or the lattcr, thc foundations must be poured "ncat" against undisturbcd soils or backfilled wilh a clean, Gce-draining, compacted structural fill. We recommend that an equivalent lluid density (GPD) of 350 pcf (pounds per cubic fooQ for lhe passivic earth pressure be used for lateral resistance. The above passive pressure assumes thttt the backfill is level or inclines upwazd behind thc foundations for a horizontal distance at Ieast hvice the depth of thc foundations below final grade. A coefficicnt of friction of 0.60 behveen thc foundations and the subgrade soils may be uscd. 7'hese am unfactored values, and a proper factor of safety should be used in calculating thc resisting fi�rccs aguinsi latcral loads on thc buildings. L1U & ASSOCIATES, INC.