Beach stabilization by the laying of a drainage layer

Abstract

In the present study, the stabilization effects of the laying of a drainage layer in a sandy beach were analyzed. The numerical model developed by Hur et al. (2011) was used to examine the characteristics of wave-sandy beach interaction with/without a drainage layer. This numerical model directly simulates Wave-Structure-Seabed/Sandy (WASS) beach interaction by considering flow through a porous medium with inertia, laminar and turbulent resistances, and determines the eddy viscosity with the Large Eddy Simulation (LES) turbulent model in a 3-D wave field (LES-WASS-3D). Based on the numerical results, it appears that the installation of a drainage layer in the beach results in a decrease in both the mean groundwater level around the foreshore and the flow moving offshore on the beach surface. Spatial distributions of the mean groundwater level and wave setup around the foreshore with various arrangements of the drainage layer and conditions of the incident wave are also discussed in this paper.