Slope stability analysis based on the Coupled Eulerian-Lagrangian finite element method

Abstract

Slope stability analysis based on the finite element method (FEM) is a powerful tool compared with the limit equilibrium (LEM) methods. However, mesh distortion of the traditional Lagrangian FEM may result in convergence difficulty of numerical simulation, and the obtained factor of safety (FOS) of the slope is not reliable. In this study, a slope stability analysis method based on the Coupled Eulerian-Lagrangian (CEL) numerical strategy with an energy based criterion is proposed. For three examples (a gentle homogeneous slope, a steep homogeneous slope and a slope with thin soft band), the results of the proposed method, the traditional Lagrangian FEM based slope stability method and the LEM method are compared. For the gentle homogeneous slope, both the proposed method and the traditional Lagrangian FEM based slope stability method can obtain credible FOS values, and the shear bands are consistent with the critical slip surface of the LEM method. The FOS value of the steep homogeneous slope is underestimated by the traditional Lagrangian FEM based method as the extreme geometry of the slope amplifies the nonlinearity and causes early termination of finite element modeling. For a slope with a thin soft band, the FOS value obtained using the traditional Lagrangian FEM based method is not valid due to severe mesh distortion. The present method can obtain reliable results for both local failure and global failure for the slope with a thin soft band.