5109 SOUND AVE 2017-08-02 - Laserfiche WebLink

July 21, 2014 Two Single-Pamily residences L&A Job No. 14-065 Page 15 the angle above horizon in degrees of the hillside behind the wall. The active soil pressure may be countered by a passive soil pressure of 400 pcf EFD over pile toe embedment in hard clayey silt deposit. The above soil pressures are unfactored ultimate values. The active soil pressure should apply on one pile spacing over the unsupported wall height and one pile diameter below. The passive soil pressure should apply on the lesser of one pile spacing or two pile diameters for soldier pile toe embedment. The soldier pile wall should be designed for a factor of safety of at least 1.5 against sliding and overturning failures under static loading. The soldier pile wall should also be designed for an 100-year seismic event. We recoinmend a pseudo static loading be used for seismic loading design of the wall. The active soil pressure should be an invert triangular distribution pressure diagram, with the magnitude of pressure at the top io be l OH[(30H+0.75 (3)/30H] EFD, where (3 is the angle above horizon in degrees of the hillside behind the wall, and H the unsupported height of the wa1L The allowable stress of the soldier pile wall elements may be increased by one third for design of short-duration seismic loading. The soldier pile wall should be designed for a factor of safety of at least 1.15 against sliding failure and 1.2 against overturning failure under seismic loading. The soldier piles should be lagged with timber boards from the top of the wall to at least one foot below finish grade in front of the wall. The timber lagging boards should be of treated wood suitable for outdoor and soil contact use. Timber lagging boards may be designed for one half the above recommended active soil pressures for static and seismic loadings to account for soil arching effect between the soldier piles. LIU & ASSOCIATES, INC.