Wave Transmission Through Submerged Rubble Mound Breakwater

The results of 30 laboratory tests on wave transmission through a permeable submerged rubble mound breakwater (SRMB) are analyzed and the available empirical equations for wave transmission coefficient (Kt) are critically evaluated. The design parameters varied systemically to investigate the impact of incident wave height (Hi), wave period (T), water depth (d), and submergence depth (ds) on the values of Kt. The ranges of variation were 0< ds /d<0.5, 0.05< Hi /(gT2) <0.02, 0.02< Hi /L<0.12, and 1.3<B/d<0.6 where B is the top width of the breakwater and L is the incident wave length. The tests were performed in a wave flume 23 m long and 2 m wide. The armor units were crushed stones with the relative density of 2.64, porosity of 41% and sieve diameter of 0.073 m. The results show that for various relative submergence depth, ds/d, (i) little correlation was found when Kt correlate with B/d. (ii) Kt correlates well with wave steepness Hi /L and with Hi /(gT2). Four commonly used predictors of Kt have been assessed against the new data among which the one is regarded to fit the data better.