Numerical model investigations on coastal structures with shallow foreshores : validation of numerical models based on physical model tests on the Petten Sea-defence

Within the framework of the European MAST-OPTICREST project prototype measurements, physical model investigations and numerical model investigations have been performed. This report describes comparisons between the test results of two-dimensional physical model investigations on the Petten Sea-defence ("Pettemer Zeewering") and numerical model computations.
Two numerical models have been applied to model wave propagation over the shallow foreshore and one numerical model has been applied to model wave motion on the structure. The models applied for wave propagation over the shallow foreshore are a spectra! wave model (SWAN) and a time-domain model (a preliminary version of the Boussinesq-type model TRITON). The model applied for modelling wave motion on the structure is a time-domain model based on the non-linear shallow-water wave equations (ODIFLOCS).
The complex shallow foreshore affects the waves considerably before they reach the toe of the dike. The severe wave breaking and surfbeat phenomena cause that wave propagation over the shallow foreshore is extremely complex, which is also the case for the wave motion on the complex structure. Therefore, this situation is considered as difficult to accurately model numerically. However, valuable predictions can already be obtained from the present versions of the models.