Frictional rheology-based 3D SPH numerical method for simulating landslide dynamics of granular flow type

Granular-flow type landslides are a prevalent and intricate natural hazard that necessitates an appropriate numerical simulation method and a reasonable rheological model to accurately capture the intricate dynamic properties. Among them, the Smoothed Particle Hydrodynamics (SPH) method has proven to be an excellent way for modeling landslides, but most of them are based on Bingham and similar rheological models, and how to simulate the dynamic process of granular flows more reasonably is still controversial. This paper proposes a three-dimensional numerical method for simulating the dynamics of granular-flow type landslide based on the frictional rheology model, which takes into account inter-particle friction. This rheology model is linked to the local normal stress through the friction coefficient and can respond well to the complex flow of particles. The proposed method combines the Navier-Stokes equations with the frictional rheology model based on the continuous medium theory within the framework of the SPH method. To validate the efficiency of the simulation method, we conducted collapse experiments with the granular flow and performed an inversion analysis of the 2016 Yishui landslide event. The results indicate that the simulation outcomes are consistent with the experimental results and are better able to describe the dynamic process of granular flows.