FEM Stability Analysis on Soil Slope with Different Constitutive Models

A typical channel crossing section of the South-North Water Diversion Project, in Shandong Province, China was chosen to carry out slope safety analysis using the finite element based strength reduction method. A revised anisotropic model was applied as a comparison to the original Duncan-Chang nonlinear constitutive models in the FEM analysis to simulate the stress and strain relationship of the soil. A displacement criterion was used to compute the factor of safety. The factor of safety calculated by the strength reduction method was verified by the Bishop method of slices which is one of the traditional limit equilibrium methods of slope stability analysis. The calculated displacements based on both models were compared with measured field displacements. It was found that although the factors of safety calculated through both models are the same, the displacement values calculated by the revised model and the Duncan-Chang models are different. It is suggested that the revised model should be applied in simulating the practical excavation stress path.