The Location of Critical Reliability Slip Surface in Soil Slope Stability Analysis

This study aims to find the difference between the slip surface having minimum factor of safety(called critical slip surface in deterministic analysis of slopes) and the slip surface having minimum reliability index(called critical reliability slip surface). The performance function used in reliability analysis was formulated by unbalanced thrust force method and the value of reliability index regarding given potential slip surface was obtained by Rosenbleuth method. The harmony search algorithm was adopted to alter the potential slip surface in order to locate the critical reliability slip surface. One complicated soil slope was analyzed and the results have shown that the critical slip surface is considerably different from critical reliability slip surface for multi-layer slopes and the reliability index of critical slip surface is larger than that of critical reliability slip surface.