SPH modeling of impact forces from heterogeneous soil-rock mixture landslides on a rigid obstruction

Abstract

Soil-rock mixture landslides frequently occur in steep mountainous regions, indicating enormous destructive potential. Consequently, these landslides have attracted much attention from researchers in recent years. This paper presents a simple and effective meshless numerical method based on Smoothed Particle Hydrodynamics (SPH) to simulate the movement and impact forces of heterogeneous soil-rock mixture landslides. In this method, soil and rock are discretized as SPH particles with different material properties and are modeled as elastoplastic and elastic materials, respectively. The ideal elastoplastic model with a nonassociated flow rule, combined with the Drucker-Prager (DP) yield criterion, is employed to describe the constitutive response. First, the paper validates the soil pressure exerted on the bottom wall of a stationary container. Second, the impact experiment of a single rock sample is verified, and the effects of the rock density, shape, and drop height are further analyzed. Last, the proposed method is employed to simulate and validate the movement and impact force of homogeneous soil landslides, followed by heterogeneous landslides. The results indicate that the proposed method is feasible for simulating the movement and impact forces of heterogeneous soil-rock mixture landslides. Additionally, this method is simple to implement, highly flexible, and capable of accommodating arbitrarily-shaped rocks. The presence of rocks alters the characteristics of the impact force and partly increases the peak impact force, particularly in steep slope scenarios. These findings enhance our understanding of the complex phenomena associated with heterogeneous landslides, including debris flows that involve multiple phases and scales, and offer significant guidance for disaster prevention and mitigation in geological engineering.