Multiphase smoothed particle hydrodynamics approach for modeling soil–water interactions

•A weakly compressible multiphase smoothed particle hydrodynamics model was developed to deal with soil-water interaction problems;•A Regularized Bingham Plastic/Mohr-Coulomb (RBPMC-) constitutive law was developed to model Soil, water and both in interaction;•Development of a new multiphase diffusive term to reduce the pressure oscillations;•Validations of the proposed SPH model through several benchmarks. In this work, a weakly compressible smoothed particle hydrodynamics (WCSPH) multiphase model is developed. The model is able to deal with soil-water interactions coupled in a strong and natural form. A Regularized Bingham Plastic constitutive law including a pressure-dependent Mohr-Coulomb yield criterion (RBPMC-αμ) is proposed to model fluids, soils and their interaction. Since the proposed rheology model is pressure-sensitive, we propose a multiphase diffusive term to reduce the spurious pressure resulting from the weakly compressible flow hypothesis. Several numerical benchmarks are investigated to assess the robustness and accuracy of the proposed multiphase SPH model.