Hydraulic performance of berm breakwaters

Berm breakwater is formed by constructing traditional breakwaters with a berm around still water level at sea side. In this research cube blocks were used on armour of the lower slope and berm whereas rock were used in upper slope of the berm breakwater. Tests were perfomed and analyzed their hydraulic performance in various water depths such as berm at sea level, berm below sea level and berm above sea level. There four type of model that used in experiments. Firstly, two of them are traditional breakwater on which armour layers were placed by using double pyramid placement method with different packing density 67% and 59%, respectively. Other models were created with double pyramid method in berm and lower slope by 59% packing density, are berm breakwaters. At one of the berm breakwater, intersection area between lower slope and berm were touched in order to provide monolithic system behaviour. There is no any contact between berm and upper slope of cube blocks at another berm breakwater. The effects of these breakwater models on wave reflection, wave run up and wave overtopping were investigated in the experiments. Experiments were performed with three different water depths to simulate the change of berm level. Seven different irregular waves were used for different storm conditions. It has been determined from the model experiments that the berm and the packing density have significant effects on wave overtopping.