Armor Stability of Overtopped Breakwater

Model tests were performed to assist the selection of stable armor sizes for the Pilgrim Nuclear Power Station breakwaters. Tests were performed on typical breakwater trunk and head sections under breaking wave conditions. The study indicated that for each armor zone there is a particular water depth at which maximum damage to that armor zone will occur. For upper level armor this water depth was less than the maximum design water stage, indicating that maximum damage to the breakwater armor will not necessarily occur under the maximum wave heights possible. The slope of the leeside was also found to be of significance for stability of armor in upper levels. More comprehensive model investigations may show that it is possible to apply existing empirical formulas for nonovertopped breakwaters to overtopped conditions, provided that an appropriate critical still water depth is used for each armor zone, and consideration is given to the leeside slope.