A new criterion for evaluating stability of slope in strength reduction FEM Based on plastic dissipation energy

Using the shear strength reduction (SSR) finite element method (FEM), the safety factor (SF) of a homogeneous slope was calculated, the results showed that the differences were inevitable because of the different adopted instability criteria and personal judgments, even if the same criterion was used. According to analyzing the characteristics of energy conversion during the slope deformation , an abrupt change of plastic dissipation energy (PDE) was found when the state of the slope changed from critical instability to the state of infinite plastic flow, this moment could be acted as the critical point for predicting the instability of a slope. Compared with the other criteria, the PDE instability criterion, to a certain degree, decreased the effects of human factor and software differences on the calculation results. The value of SF calculated using the PDE criterion was very close to the traditional limit equilibrium approach, which proved the new criterion was practical and reliable. The PDE criterion, therefore, can provide a powerful method for obtaining uniform results during slope stability analysis using the elastoplastic FEM based on the SSR technique.