Three-dimensional stability analysis of unsaturated soil slopes with cracks under infiltration

Most classical approaches for evaluating the stability of soil slopes with cracks are performed under two-dimensional (2D) condition. Three-dimensional (3D) effect and suction-induced effect of unsaturated soils are generally ignored in assessing the slope stability. This paper develops a 3D limit analysis method to evaluate the stabilily of an unsaturated soil slope with tension cracks under steady infiltration. The boundary-value problem is formulated based on the 3D failure mechanism by taking the effects of suction, effective unit weight of soils and the tension crack into account. Examples are given to illustrate the 3D effect, the suction-induced effect as well as the effect of infiltration on the slope stability.