Abstract:Based on the theory of lower bound limit,finite element discreteness technique and nonlinear mathematical programming,the finite element plastic limit analysis method is used to evaluate the stability of rock slope. By using nonlinear Mohr-Coulomb yield condition,equilibrium condition,stress boundary condition and stress discontinuity equilibrium condition,the finite element modes of joint elements with zero thickness and equal thickness are proposed in the plastic limit analysis;and the nonlinear mathematical programming models of finite element plastic limit analysis,which contains joint elements,are established. Then,the optimization strategy of nonlinear mathematical programming problem is provided. At last,the stabilities of three 2D slopes are analyzed with the presented method. The results are compared with those obtained by other approaches. The feasibility of the method is verified.