Seismic stability of expansive soil slopes reinforced by anchor cables using a modified horizontal slice method

Abstract

Earthquake-induced slope failures are common occurrences in engineering practice and pre-stressed anchor cables are an effective technique in maintaining slope stability, especially in areas that are prone to earthquakes. Furthermore, the soil at typical engineering sites also exhibit unsaturated features. Explicit considerations of these factors in slope stability estimations are crucial in producing accurate results. In this study, the seismic responses of expansive soil slopes stabilized by anchor cables is studied in the realm of kinematic limit analysis. A modified horizontal slice method is proposed to semi-analytically formulate the energy balance equation. An illustrative slope is studied to demonstrate the influences of suction, seismic excitations and anchor cables on the slope stability. The results indicate that the stabilizing effect of soil suction relates strongly to the seismic excitation and presents a sine shape as the seismic wave propagates. In higher and steeper slopes, the stabilizing effect of suction is more evident. The critical slip surface tends to be much more shallow as the seismic wave approaches the peak and vice versa.