Abstract: The rigid limit equilibrium method has been widely used to analyze the wedge stability.However,it does not satisfy equilibrium equations,and it still requires assumptions regarding the force reactions,which may result in false results.A new method based on the lower bound method to analyze the stability of wedge slopes is proposed.It does not require assumptions regarding the wedge failure mode,the force reactions or the number of slide planes.The block-structural plane model is used for constructing the statically admissible stress fields which satisfy the equilibrium conditions,boundary conditions and yield criteria.By using the idea of nonlinear programming,the lower bound limit analysis model of mathematical programming for wedge stability is established.Finally,three examples are used,and the results agree well with those from the finite element and the upper bound methods.