Sliding stability and seismic design of retaining wall by pseudo-dynamic method for passive case

Abstract

Knowledge of the influence of soil inertia and wall inertia on the design of a retaining wall is very important and more so under earthquake conditions. In this paper, by using the pseudo-dynamic seismic forces acting both on the soil and the wall, the design weight of the wall required under seismic conditions is determined under passive earth pressure conditions. The present pseudo-dynamic method considers time, phase difference and effect of amplification in shear and primary waves traveling through both the backfill and the retaining wall due to seismic excitation. A model rigid vertical retaining wall under passive earth pressure conditions with cohesionless backfill material has been considered in the present analysis. Results in graphical form show the non-linear variations of the soil passive resistance factor ( F T), wall inertia factor ( F I) and combined dynamic factor ( F w) with respect to the horizontal seismic acceleration coefficient ( k h), required for the design of the wall. The effects of parameters such as wall friction angle, soil friction angle, shear wave velocity, primary wave velocity, period of lateral shaking, horizontal and vertical seismic accelerations and amplification factor on the sliding stability of the retaining wall have been studied. With the increase of seismic accelerations both in horizontal and vertical directions, the sliding stability of the retaining wall decreases significantly.