A numerical analysis is performed to predict the actual beach profile change due to cross-shore sediment transport during severe storm. In the existing cross-shore beach erosion studies, the calculation of cross-shore sediment transport includes only continuous process of beach erosion but the stability of beach slope which expects the time of beach breakdown during erosion is not considered. In this study the process of cross-shore beach erosion and beach profile change are simulated, and the stability of beach slope using the critical equilibrium analysis is analyzed on every changing beach profile in every given time to predict the actual change of cross-shore beach profile. The measured cross-shore beach profile, storm surge level and wave height in Florida in U.S.A. are used in this study and various values of soil modulus based on the existing studies are applied in the stability analysis of beach slope.
Recently, Korea coastlines and profiles have been variously changed due to construction of harbors and coastal structures. Change of coastline and profile results in change of wave height, wave breaking, wave driven-current, etc., and it causes some coastal problems, such as coastal erosion and accretion, coastal structure damage, etc.. Since continuous retreat of coastal line and loss of beach sand due to coastal erosion causes geotechnical problems and eventually affects stability of coastal structures and houses adjacent to coastline, it is crucial to predict erosion process and stability of beach slope to protect coastal structures. Sediment transport, generally, is divided into the longshore sediment transport and the cross-shore sediment transport. The longshore sediment transport is driven primarily by an alongshore wave-induced current produced by waves approaching at an angle to the shore. The cross-shore sediment transport is considerably generated during storm. Dean(1977) introduced the equilibrium beach profile theory in his study of beach erosion.
