Soil Response Induced by Wave Shoaling and Breaking on a Sloping Seabed

Abstract

This study investigates the seabed response induced by wave shoaling and breaking on a sloping seabed through numerical modeling. A coupled approach is employed, integrating a Reynolds-Averaged Navier–Stokes (RANS) wave model with a poro-elastic soil model based on Biot’s consolidation theory. The wave model incorporates a stress- (Formula presented.) turbulence model to mitigate the tendency to overestimate turbulence intensity during wave breaking. The numerical simulations capture key hydrodynamic processes such as wave transformation, breaking-induced turbulence, and the evolution of pore pressure and soil stress within the seabed. Model validation against analytical solutions and experimental data confirms the reliability of the numerical framework. The study simulates two types of breaking waves: spilling and plunging breakers. The results indicate that wave breaking significantly alters the spatial and temporal distribution of pore pressures and effective stresses in the seabed. In particular, the undertow generated by breaking waves plays an important role in modulating seabed responses by inducing asymmetric pore pressure and stress distributions. The influence of soil permeability and the degree of saturation on wave-induced responses is investigated, showing that higher permeability facilitates deeper pore pressure penetration, while under lower permeability conditions, a higher degree of saturation significantly enhances pore pressure transmission. Additionally, different breaker types exhibit distinct seabed response characteristics, with plunging breakers causing stronger nonlinear effects. These findings provide valuable insights for the design and stability assessment of marine and coastal infrastructure subjected to dynamic wave loading.