Development of a newly coupled DSPH-DDA technique for coupling problems in geotechnical hazards

Abstract

Geotechnical hazards usually involve interactions between different materials or phases such as water-structure interaction, water–rock interaction, soil-structure interaction, or soil-rock interaction. Accurate and efficient simulation of such phenomenon can be challengeable due to the complex interactive mechanism and large deformation. A newly coupled DualSPHysics (an open-source Smoothed Particle Hydrodynamics solver platform) – Discontinuous Deformation Analysis (DSPH-DDA) technique is developed by combination of two- and three-dimensional DDA and DualSPHysics. DDA is executed in CPU with independent time step size, and a synchronizing technique is developed to maintain the pace between two systems. Besides, for describing soil behavior, an elastic–plastic soil constitutive model is also incorporated into DualSPHysics. The spring-dashpot contact model is adopted to idealize particle-block interactions. Five numerical examples are conducted to demonstrate the performance of the newly coupled DSPH-DDA technique, including the soil column collapse, the free surface flow impacting on an elastic structure, the dam break flow impacting on cubes, modular-block soil retaining wall collapse, and the tunnel face collapse with varied rock contents of soil-rock-mixture model ground. The simulation results are consistent with the experimental data. Conclusively, this newly coupled DSPH-DDA technique is applicable to describe large deformation and failure behavior of coupling problems in geotechnical hazards with high accuracy and calculation efficiency.