Experimental Study on Effects of Initial Berm Width and Stone Grading on the Stability of Berm Breakwaters

The predominant principle included in the design of reshaping berm breakwaters is the supply of a wide berm at or nearby the water level with less armor stone size than that used in conventional design, which are allowed to reshape until an equilibrium slope is attained. In the present study, the recession of the berm due to wave and structure parameters has been investigated based on two dimensional experimental modeling in a wave flume. A series of 156 tests have beencarried out with irregular waves with JONSWAP spectrum to observe the behavior of the structure.To cover the effects of initial berm width and stone sizes on berm recession, several wave parameters such as wave height, wave period and storm duration have been considered. To analyze the results, the experimental data are presented together, leading to a formula for prediction of the berm recession considering foregoing parameters, i.e. wave and structural parameters.