INVESTIGATING OF WAVE PARAMETERS INFLUENCE ON WAVE REFLECTION FROM BERM BREAKWATER

In this research, the effects of wave parameters (wave period, wave height and storm duration) on wave reflecton from berm breakwaters have been investigated. The research has been performed using physical models (scale1:40) in the wave flume of soil Conservation and Watershed Managment Research Center (SCWMRC), the ministers of Jihad - e - Keshavarzi. To study the effects of the above mentioned parameters, totally 83 tests were performed using irregular waves. The JONSWAP spectrum was used in all tests. The significant wave heights in prototype scale varied from 1.5 to 4.5 meter and the significant wave periods were 7,8,9,10,12 and 14 seconds. The tests were carried out using first 1000 waves and then repeated second and third 1000 waves. The reflection coefficients were measured using three gauges method (Mansard, 1980). To show the effects of the wave parameters, the reflection coeffiicient have been determined as a function of the wave wteepness and a new parameter. The results of the experimental tests have shown that the reflection coefficient decrease with increasing the wave steepness and they increase with increasing. Besides, the experimental results have shown that the wave reflection coefficient decrease slightly with increasing the storm duration.