Abstract: The adjustment of nonlinear stress is not taken into account in the limit equilibrium analysis of rigid body; and it is difficult to judge the convergence of the shear strength reduction method with FEM. To solve these problems, based on multi-grid method, structure grid for nonlinear FEM and sliding surface grid for calculating safety factor were established separately. So the sliding safety factor of arbitrary sliding surface or sliding blocks can be obtained. Thus limit equilibrium analysis can be integrated with nonlinear FEM. To increase calculating scale and speed, a 3-D parallel finite element code based on element-by-element method, TFINE.Pfem, is developed and used. The influence on result precision by grid were analyzed. Then it is applied to the stability analysis of Jinping high slope. The contrast analysis show that the safety factor obtained from the method proposed is larger than that of limit equilibrium analysis of rigid body because of considering of adjustment of nonlinear stress. The method porposed is accord with real conditions.

Key words: slope, stability, multi-grid method, finite element method, parallel computing