Nearshore Circulation at a Coastal Defence System in Sicily. Physical and Numerical Experiments.

In 2008, small scale physical model tests of a new coastal defence to be built along the Northwest coast of Sicily (Italy) have been conducted at 3D wave basin of the Dept. of Hydraulic, Geotechnical and Environmental Engineering (D.I.G.A) of the University of Naples ???Federico II???. The defence structure consisted of two detached low-crested breakwaters armored with the single layers systems ACCROPODETM II and ECOPODETM. The experiments were conducted under the supervision of Universities of Calabria and Salento and with the kind support of Concrete Layer Innovation (CLI). Originally, the scope of physical modeling was to check the hydraulic stability of the structures, which resulted in fact absolutely stable. Yet, it was emphasized that also the current regime induced by the breakwaters deserved to be analyzed. This because the new project is located at a site where the bathymetry is rather irregular, with the presence of a wide rip channel that extends orthogonally to the mean direction of the shoreline. Thus, a new set of experiments have been carried out at the DIGA wave basin; physical model tests have been combined with numerical simulations performed with the software MIKE 21. The paper discusses preliminary results of this investigation.