Soil-water strong coupled ISPH based on u−w−p formulation for large deformation problems

This paper is dedicated to the introduction of a strong coupled soil–water interaction formulation based on an incompressible smoothed particle hydrodynamics (ISPH) framework. The method is based on the u−w−p Biot's formulation and adapted to a semi-implicit projection method for incompressibility condition of pore water and soil grains. The SPH Lagrangian particles move according to the soil velocity, while water variables are embedded into such soil particles. This allows to solve the pressure Poisson equation in a strong coupling way, in addition to enable to update the Darcy's drag force implicitly. A simple boundary treatment on natural boundary conditions for soil particle is proposed to take into account both non-penetration and friction effects. The proposed method was verified and validated through a series of numerical tests resulting in good agreements with both theoretical and experimental results. Finally, we show the applicability of the proposed method in the famous Selborne experiment, a full-scale slope failure problem.