Physical model study of water piling-up behind low crested structures

In this paper the experimental results obtained through the physical model investigation performed in the flume of Padova University on a typical low crested structure is presented. Aim of the investigation was to evaluate the behaviour of this kind of structure in terms of reflection and transmission of incident waves, as well as the study of the wave overtopping phenomenon and the associated increase in the water levels behind the breakwater (water piling-up). The wave-structure interaction was examined by reproducing about 70 irregular wave attacks. In the first part of the study a rubble mound permeable breakwater was analysed, while in the second part of the research an impermeable plate was placed on the landward slope of the structure, in order to study in more details the complex phenomena of the wave overtopping over the structure and of the seepage through it, also related to the piling-up level at the back of the structure.