Slope failure criterion: A modification based on strength reduction technique

摘要

The FLAC method based on finite difference technique can simulate the behaviour of slopegeomaterials which undergo plastic flow when their yield limits are reached. Thus it can forecast the deformationafter slope failure,so it is widely used in slope stability analysis. This paper explored the exiting criteria of slopefailure and relevant limitations. Considering the fact that plastic shear strain catastrophe occurs when the pointsin the critical slice change from a limit equilibrium state to plastic flow after yielding,this paper focused on thechanging rate of plastic shear strain of crucial points in the critical slice with the strength reduction coefficientand made a modification for the slope failure criterion: when the catastrophe of the changing rate of plastic shearstrain occurs,the corresponding state is a critical instability state and the relevant strength reduction coefficientis a critical factor of safety of the slope. The case analysis in this paper validated that the modified slope failurecriterion is rational and feasible.