Application of landslide progressive failure mechanical model based on the critical stress state

According to the physical significance of the slice method of slope, the strength softening behavior of the geo-material is characterized by strength reduction coefficient. The unbalanced thrust method hypothesis is generalized. And during the same state of peak shear stress and strain, the progressive failure process of landslide is simulated by using the perfect elastic-plastic model (PEPM) and the complete process shear stress-strain constitutive model (CPCM). Then, a determination method with critical stress state is proposed, and the partial strength reduction method (PSRM) is employed. The unbalance thrust force and driving sliding force become greater and greater, and the frictional resistance gets smaller and smaller during the deformation failure process. Taking the Daochicun landslide located in Enshi, Hubei Province as an example, the evolution characteristics in progressive failure process are revealed by the proposed method with three sorts of numerical simulations (PSRM, PEPM and CPCM). Results show that:the proposed generalized slice block method with the three numerical simulations can describe the progressive failure process of the landslide, the factor of safety of the PSRM and PEPM are more than that of the CPCM.