Normalized correction of soil-water-coupled SPH model and its application

The smoothing approximation in the traditional smoothed particle hydrodynamics (SPH) method often leads to an unreasonable evaluation of field variables and their gradients in areas of boundary, free surface and interface of phases, called as the tensile instability that accounts for the fluctuations of pressure and stress. For the lack of researches on the accurate SPH model in geotechnical engineering, this research proposes a water-soil-coupled SPH model that is treated by the normalized correction and can avoid the tensile instability to some extent. In the proposed model, liquid phase (pore water) and solid phase (soil skeleton) are assigned to different layers according to the Biot’s theory of consolidation, the pressure of the liquid phase is calculated based on the equation of state, and the elastic model is used to describe the mechanical behavior of soil skeleton. The proposed SPH model is applied to the analysis of 3D dam-break case, geostatic stress states of a dike model without or with groundwater. By comparing the results of the corrected SPH model, uncorrected SPH model and FEM analysis, it has been proved that the corrected SPH model with good agreement with the FEM simulation has a better performance than the uncorrected model, and this research can provide several insights for the application of SPH method in geotechnical engineering.