A nonlinear variation safety factor calculation method for slopes based on slide mass shear constitutive model and landslide displacement

Landslide displacement dynamically drives the evolution of slope stability, a critical phenomenon empirically demonstrated by numerous early-warning cases. Yet, conventional slope stability calculation methods fundamentally fail to capture this displacement-dependent behavior. Knowing the effect of landslide displacement on slope stability can greatly improve the efficiency of landslide warning and reduce the loss caused by landslide disaster. For this reason, this paper constructs a rock shear constitutive model based on damage mechanics. Considering the parameter differences between small-size specimens and large rock masses due to the size effect, the Hoek-Brown criterion is introduced. By the Hoek-Brown criterion, the rock shear constitutive model was successfully transformed into a slide mass shear constitutive model. Finally, the slide mass shear constitutive model was brought into the slope model and an expression for the dynamic calculation of slope safety factor based on landslide displacement was derived. In addition, Finite Difference Method (FDM) was used to verify the validity of the dynamic calculation expression of slope safety factor in this paper. The results show that each rock interface on the slip surface of the slope owns a different shear constitutive curve due to the different normal loads. The factor of safety of the slope will show a nonlinear variation with the increase of the landslide displacement.