XBeach simulation of a hybrid coastal protection: A Galveston Seawall test case

Description

The City of Galveston is protected from extreme storm impact by a 17-km concrete seawall facing the Gulf of Mexico. Recent studies have shown that the seawall may not be sufficient to protect against a 100-year design storm. Since raising the seawall disconnects the city from the beach and may be very costly, a hybrid approach is explored in which the existing hard structure is fronted and covered by a layer of sand. By means of numerical simulations，the hydro- and morphodynamic effects of adding a sand cover to the Galveston Seawall under extreme storm conditions are further investigated. It was found that by adding a sand cover over the seawall, maximum dissipation is spread over a larger cross-shore extent. This led to the reduction of the wave height at the face of the hybrid structure, as well as the generation of more wave-induced setup. Different hybrid design configurations were simulated, which varied in sand cover dimensions. Differences in wave attenuation, wave-induced setup and required sand cover volumes are discussed. It was found that a hybrid measure shows potential in reducing wave impact during extreme storm events, thereby reducing the required elevation of the Galveston Seawall.

Period	30 Dec 2018
Event title	36th International Conference on Coastal Engineering, ICCE 2018
Event type	Conference
Conference number	36
Location	Baltimore, United States, MarylandShow on map