Seismic design factor for sliding of waterfront retaining wall

Abstract

A detailed methodology is presented for obtaining seismic design factors for sliding of a waterfront retaining wall using the pseudodynamic approach, which considers the effects of period of lateral shaking, shear and primary wave velocities, time, and seismic accelerations. Water is considered on both the upstream and downstream sides of the wall. Results are presented in terms of design factors for sliding: thrust factor FTwet, inertia factor FIwet, and the combined dynamic factor FWwet. Using FWwet, the weight of the wall needed to maintain stability against sliding under seismic conditions is obtained. The variation in upstream and downstream water heights seriously challenges the sliding stability of the wall. Variation in the horizontal and vertical seismic acceleration coefficients, soil and wall friction angles, and period of lateral shaking have a significant effect on the stability design factors, whereas the effect of pore pressure ratio was found to be a minimum. The weight of the wall needed for a kh of 0·3 is almost double what would be needed if kh were zero. Comparison of results shows a good match with an existing methodology, but for the dry backfill case with no upstream water. Results for the wet case are claimed to be unique.