Stability of Unsaturated Soil Slopes with Cracks under Steady-Infiltration Conditions

Abstract

Most classical approaches for evaluating the stability of soil slopes with tension cracks are performed under dry and/or saturated conditions. The suction-induced effect of unsaturated soils is generally neglected in assessing slope stability. This article presents an analytical framework for assessing the stability of unsaturated soil slopes with tension cracks under one-dimensional (1D) steady-infiltration conditions using the limit-analysis method. The boundary-value problem was formulated based on the log-spiral failure mechanism by taking the effects of suction stress, effective unit weight of soil, and tension cracks into account. A simplified method was developed to calculate the external work rate of unsaturated soil weight. Detailed investigations of the effects of suction, Poisson’s ratio, steady infiltration, and water in tension cracks on the slope stability are presented.