Post-failure movement characteristics and parameter back-analysis for landslides considering effect of strength parameters

The dynamic characteristics of flow process of landslides such as the sliding distance and the expanding velocity are of great significance to the prevention and control of landslide hazards. The current studies on landslide simulations usually focus on the reappearance of flow process and the influence mechanism of parameters, and with the absence of parameter inversion analysis, they are insufficient to provide detailed data support for the prevention of landslide disasters. Based on the SPH method, the relationship between the strength parameters and the viscosity parameter is established using the equivalent viscosity and the Bingham fluid model so as to form the flow-process simulation method for landslides. The inversion analysis is realized by the combination of the strength reduction technique and the flow profile comparison. Through the simulation and comparison of the Fei Tsui Road landslide in the Hong Kong SAR, the applicability of the proposed method is validated. On this basis, taking the 7·19 landslide in the Boli Village, Yanyuan County of Sichuan Province as the study case, the sliding distance and the expanding velocity under different strength-reduction coefficients are analyzed, and the evolution law of dynamic characteristics such as the sliding distance and the peak velocity are discussed. Comparing with the survey data of topography after the landslide, the strength parameters in the flow process can be preliminaryly determined, which is beneficial to the prevention and control of landslide hazards.