Stability Analysis of Three-Dimensional Slopes Considering the Earthquake Force Direction

摘要

Simplified 3D Spencer's method is proposed to evaluate the stability of slopes under earthquake force and a random search algorithm is used to determine the critical slip surface. A computer code was written in Matlab to determine the critical slip surface and calculate its safety factor and direction of sliding (DOS). The applicability of the presented code is verified by reanalyzing three slope stability problems. Then, a comparison is made to investigate the effects of the direction of earthquake force on the factor of safety and the DOS of the critical slip surface. Accounting for the effects of the direction of earthquake force, the difference in safety factors, and the DOS can be up to 40% and 40 degrees, respectively. Finally, a parametric study is also conducted to determine the effects of the soil strength parameters (c, phi). It is found that the effective cohesion c and friction angle phi of the soil have nearly no influence on the unique DOS of the critical surface. Application of the presented approach into 3D slopes under quasistatic load is straightforward.