Seismic Response Analysis of Submerged Slopes Using Coupled SPH–DEM Scheme

Abstract In this study, the seismic response of submerged slopes is evaluated using a coupled smoothed particle hydrodynamics (SPH)–discrete-element method (DEM) framework. In this technique, DEM particles represent the soil grains and the fluid domain is idealized using SPH. The interaction forces between the two phases are estimated based on well-established semiempirical equations. The submerged slope was created utilizing the coupled scheme and subjected to a variety of base excitations with various amplitudes and frequencies. The results suggest that the stronger input motion generally induces larger displacements and shear strains. In addition, the frequency of the input motion can also have a significant effect on the level of deformation the system experiences. It was observed that the soil strength and stiffness can severely degrade due to pore pressure buildup, leading to excessive lateral deformations at input motion frequencies considerably lower than the initial fundamental frequency of the deposit. In contrast to the level parts of the model near the slope toe and crest, soil dilation close to the slope surface leads to a drop in the excess pore pressure and a temporary regain in soil strength and stiffness reflected by sharp acceleration spikes and asymmetrical shear stress–strain loops.