SPH-DEM Modeling of the Hydraulic Stability of 2D Blocks on a Slope

The numerical simulations of wave interactions with armor blocks on rubble-mound breakwaters will enable a stronger understanding of breakwater failure and therefore increased malfunction prevention. This paper presents a two-dimensional (2D) SPH-DEM model, which combines smoothed particle hydrodynamics (SPH) and the discrete-element method (DEM) to simulate the wave-structure interaction on a slope and predict the hydraulic stability of the 2D structure. A particle method combined with a Riemann solver evaluates the hydrodynamic loads on the discrete blocks, while a multisphereDEMdescribes the movement of the solids from the wave attacks. An interfacial force-balance condition enables coupling between the fluids and the solids. A series of experimental tests were conducted to validate the SPH model. The simulation of water entry of the wedge was compared with previous experiments. The wave interactions with massive cross-shaped blocks on a slope were also simulated in 2D. Numerical results are presented showing the details of large deformations of the free surface on the slope, the velocity field, and the hydraulic pressures on the armor units, and the nature of the changes in position of the blocks near the toe of the slope during the wave attack. These results facilitate an improved understanding of the interaction between waves and breakwaters. (C) 2014 American Society of Civil Engineers.