Probabilistic analysis of a cohesion-frictional slope using the slip-line field theory in a Monte-Carlo framework

A new instability criterion based on the slip-line field theory is proposed to conduct the probabilistic analysis of slope in a Monte-Carlo framework, and sensitivity studies were carried out to investigate the feasibility of the proposed criterion in deterministic and probabilistic analysis for a cohesion-frictional homogeneous slope. It is found that the slope is in the limiting equilibrium condition when the critical slope contour obtained from the slip-line field theory intersects with the slope at the toe of the slope. The proposed method makes no assumption about the critical failure surface in advance and can be used to quantify the stability of slopes. The factor of safety and critical failure surface agree well with those obtained from the Bishop's simplified method, and the probability of failure calculated by the proposed method is close to those obtained from Direct MCS based on the Bishop's simplified and the first-order reliability method (FORM). The proposed method does not need to calculate the factor of safety and critical failure surface for determining the probability of failure, which improves the computational efficiency.