Numerical Study for Soil Response Around Submerged Breakwaters with Bragg Reflection

Abstract

A better understanding of soil behavior in a seabed foundation around submerged breakwaters under combined wave and current loadings has become crucial regarding the design and maintenance for such breakwaters. Bragg effect is considered in this study, which is one of the important factors that influence the flow field and soil response in the vicinity of multiple breakwaters. The wave-current induced dynamic soil response (effective stresses, pore pressures and displacements) and its resultant residual liquefaction in a loosely deposited seabed foundation around multiple breakwaters are investigated. In this study, the wave motion is governed by VARANS equation and the Biot’s [Formula: see text]–[Formula: see text] approximation is used to govern soil-fluid interactions in porous medium. The elasto-plastic constitutive model (PZIII) is used to reproduce the plastic soil behavior in seabed foundation under long-term cyclic ocean loading. Numerical results show that the flow motion can be largely changed due to Bragg effects. The construction of breakwaters significantly change the stress field in seabed foundation. Parametric study shows that, under the strongest Bragg effect, the presence of currents, soil properties and wave characteristics have great impact on the liquefaction potential.