Analysis of the Active Earth Pressure of Sandy Soil under the Translational Failure Mode of Rigid Retaining Walls Near Slopes

To accurately obtain the active earth pressure of a limited-width sandy fill behind a rigid retaining wall under translational failure, finite element limit analysis (FELA) was used to simulate the failure mechanism of the limited-width sandy fill behind the wall under the translational failure mode of the rigid retaining wall. Based on the different development characteristics of the sliding surface, three kinds of failure mode characteristics were identified. Semianalytical expressions of the active earth pressure were obtained by using the limit equilibrium method and the finite difference method, introducing the horizontal differential element and considering the soil arching effect behind the wall. The parameter analysis shows that the width-to-height ratio of the fill and the slope angle play a controlling role in the failure mode and that the position of the resultant force corresponding to the active earth pressure under different failure modes also changes significantly. The active earth pressure exerted on the retaining wall is maximized at a particular threshold of the friction angle at the wall–fill interface, which varies according to the geometric shape of the backfill and its internal friction angle.