Experimental and analytical study of passive earth pressure behind a vertical rigid retaining wall rotating about base

Abstract

This article investigates the passive earth pressure through the laboratory-scale test conducted on a 600 mm rigid retaining wall when rotated about its base. An advanced digital image processing technique such particle image velocimetry (PIV) is employed for monitoring of slip plane propagation. The test results show a nonlinear distribution of earth pressure and the failure occurs at a maximum top displacement of 0.1H. A failure surface emanating linearly from upper part of backfill propagates downward and becomes curved near bottom as per PIV results. Further, an analytical model is proposed to determine the passive earth pressure behind a vertical rigid retaining wall considering the key inferences drawn from the test results which are arching effect in soil, curvilinear failure surface and the magnitude of rotation at failure. Arching is incorporated in the model by considering three arch shapes (circular, parabola and catenary). The results of the mathematical model are corroborated with test results which establish a good agreement. All the arch shapes draw an agreeable prediction with test values whereas parabolic shape gives the most conservative value in this regard. Parametric studies have indicated pronounced arching occurrence for soil having ϕ > 35° and wall having δ > 0.67ϕ.