Abstract: Three-node triangular elements together with the linearized yield criterion are commonly used in the finite element upper bound limit analysis. Therefore, the method is of low calculation precision. Aiming at this problem, a method of upper bound limit analysis using six-node triangular elements and second-order cone programming is developed to investigate the slope stability subjected to pore water pressure and earthquake loads. The proposed method formulates the slope stability problem as a second-order cone programming with constraints based on the yield criterion, flow rule, boundary conditions, and the energy-work balance equation. The optimization problem is solved by a state-of-the-art interior-point method, and the strict upper bound solutions can be obtained. Finally, the results of two numerical examples are compared with published solutions, which demonstrate the validity of the proposed method. The results also indicate that the mesh-dependence phenomenon is overcome and the calculation precision is improved even for large internal friction angel of materials.

Key words: slope stability, limit analysis, upper bound theorem, second-order cone programming, finite element