Seismic design of retaining wall by considering wall-soil inertia for active case.

Abstract

Effect of both the wall and soil inertia must be considered for the design of retaining wall under seismic conditions. In this paper, by considering pseudo-dynamic seismic forces acting on the soil wedge and the wall, the required weight of the wall under seismic conditions is determined for the design purpose of the retaining wall under active earth pressure condition. The method proposed considers the movement of both shear and primary waves through the backfill and the retaining wall due to seismic excitation. A rigid vertical retaining wall supporting cohesionless backfill with horizontal ground has been considered in the present analysis by considering planar rupture surface. Results in graphical form show the variations of proposed design factors viz. soil thrust factor (F_T), wall inertia factor (F_I) and combined dynamic factor (F_w) with respect to horizontal seismic acceleration coefficient (k_h), required for the design of the wall under seismic conditions. Also the effects of variation of parameters like soil friction angle, wall friction angle, vertical seismic acceleration, period of lateral shaking and amplification factor on combined dynamic factor have been studied. A comparative study between the present theory and available pseudo-static results has shown the merits of the present analysis.