Publication

Abstract : A theoretical model was developed to determine the seismic passive earth pressure on vertical cantilever retaining walls supporting a two-layered cohesionless backfill with a loose sand layer overlying a dense sand stratum. Seismic inertial forces were considered in the analysis by employing the classical pseudostatic approach. The theoretical formulation was developed based on the method of stress characteristics, which does not require any predefined failure mechanism to initiate the analysis. The charts are presented in terms of passive earth pressure coefficient, which includes the contribution of both the layers. In addition to the generation of the actual failure mechanism, rapid mobilization of stresses at the layer interface and at the wall backface is presented in the form of normalized stress contours. The failure surface and the passive earth pressure distribution behind the wall were found to be nonlinear, with different input parameters. The passive resistance of backfill soil decreased in the presence of the loose sand layer resting on the denser soil stratum.