A two-fluid SPH model for landslides

A multi-fluid weakly compressible Smoothed Particle Hydrodynamics (SPH) method is used to model non-cohesive sediment transport. The present SPH model is based on Hu and Adam's (2006) multi-fluid formulation and Unified Semi-Analytical Wall (USAW) boundary conditions (Ferrand et al., 2013). It is then able to handle accurately density and viscosity discontinuities at the interface of two immiscible fluids, guaranteeing the continuity of velocity and shear-stress across the interface. On the other hand, the USAW boundary conditions ensure an accurate pressure and shear-stress treatment at the wall even for complex boundary geometries. In addition, a rheological model is used in order to take into account the non-Newtonian behavior of the sediment. The present work aims at modeling a submarine landslide. The collapsing mass of non-cohesive sediment (e.g. sand) is then modeled as a shear-thinning fluid using a Bingham rheological law. The proposed formulation as applied to Assier-Rzadkiewicz's landslide case (Assier-Rzadkiewicz et al., 1997). Results are compared with experimental data as well as numerical results (Capone et al., 2010) and a good agreement is obtained.