A multi-layer SPH method to simulate water-soil coupling interaction-based on a new wall boundary model

Based on the smoothed particle hydrodynamics (SPH), a multi-layer particle method is established to accurately simulate the deformation and motion of the water-soil coupling interaction, considering the seepage process and the variation of the volume fractions of water and soil. The weakly compressible model is used for water, while the Drucker-Prager elastoplastic constitutive model is employed for soil. In this study, we have adopted a new wall boundary model for water-soil coupling, considering the physical relationship between boundary particles and internal particles, which improves the numerical stability of the SPH simulation. Three numerical examples are conducted to validate the accuracy of the SPH method and the new wall boundary model. The distribution of the saturated soil foundation stresses is simulated to validate the accuracy of the SPH method under static water conditions and the superiority of the new wall boundary model. The seepage process in a soil dam and the underwater landslide are simulated to validate the ability of the current SPH method for simulations of water-soil coupling interaction. These results confirm that the current SPH method has good stability and accuracy, making it suitable for simulating fundamental water-soil coupling processes.