AbstractsPhysics

In a consortium Iv-Infra has made a proposal for a storm surge barrier to protect the city of New Orleans against hurricanes like Katrina. The design is a pile supported concrete structure with a considerable complex superstructure. The superstructure of the reference design consists of a perforated inclined wall and a vertical back wall. Since the hydraulic processes and variable wave pressures on the superstructure are not trivial and hard to predict more research is required to design similar structures in the future. The objective of this study is to get an understanding of the hydraulic processes and variable wave pressures on the reference structure. The research is divided in an analytical part and a part of physical model tests. The near shore wave conditions are calculated with SWAN. The design conditions are a storm surge of 6m, a wave height of 2,2m and a wave period of 5,25s. In order to obtain an understanding of the hydraulic processes and wave pressures on the reference structure first a simple and impermeable sloping structure is considered. It is found that for the local conditions in combination with steep sloping structures non-breaking wave conditions occur. Therefore it is assumed that the linear wave theory can be applied for determining the variable wave pressures. A model is made for the influence of a gap at the bottom of an inclined wall on wave reflection; wave run-up and wave transmission. In the physical model tests different experimental set-ups are tested. The expectations drawn on the basis of the results of the analytical part are verified by the results from the model tests.