5109 SOUND AVE 2017-08-02 - Laserfiche WebLink

July 21, 2014 Two Single-Family residences L&A Job No. 14-065 Page 17 bearing soils should be verified by a geotechnical engineer after the footing trenches are excavated and before the footings poured. • The minimum depth to bottom of perimeter footings below adjacent final e�tcrior grade should be no less than l8 inches. The minimum depth to bottom of the interior footings below top of floor slab should be no less than 12 inches. • The minimum wridth should be no less than 16 inches for continuous footings, and no less than 24 inches for individual footings, except those footings supporting light-weight decks or porches. A one-third increase in the above recommended allowable soil bearing pressure may be used when considering short-term, transitory, wind ar seismic loads. Far footing foundations designed and constructed per recommendations above, we estimate that the maximum total post-construction settlement of the buildings should be 3/4 inch or less and the differential settlement across building width should be 1/2 inch or less. Lateral loads on proposed buildings may be resisted by the friction force between the foundations and the subgrade soils or the passive earth pressure acting on the below-grade portion of the foundations. For the latter, the foundations must be poured "neat" against undisturbed soils or backfilled with a clean, free-draining, compacted structural fill. We recommend that an equivalent fluid densiTy (EFD) of 275 pcf(pounds per cubic foot) for the passive earth pressure be used for lateral resistance. The above passive pressure assumes that the backfill is level or inclines upward away from the foundations for a horizontal distance at least ].5 times the depth of the foundations below the final grade. A coefficient of friction of 0.55 between the foundations and the subgr'ade soils may be LIU & ASSOCIATES, INC.