Majid Ehsani - Department of Civil Engineering, Isfahan University of Technology
Mohammad Navid Moghim - Department of Civil Engineering, Isfahan University of Technology
Mehdi Shafieefar - Department of Civil and Environmental Engineering, Tarbiat Modares University
Amir Mostaghiman - Department of Civil Engineering, Isfahan University of Technology

One of the issues that emerge from an efficacious design of berm breakwaters is an estimation of wave reflection. In the present study, the wave reflection of a multi-layer berm breakwater (MLBB) has been studied based on model experimentation. To gain this goal, two-dimensional model tests have been carried out in a wave flume at Tarbiat Modares University. Irregular waves were generated using the JONSWAP spectrum, under which the effect of various parameters like wave height, wave period, water depth, and berm elevation from still water level is investigated on the wave reflection. Achieved outcomes of this study propose a new formula estimating MLBBs wave reflection. Ultimately, the performance of the derived formula against the existing formulae proposed by other researchers is checked thoroughly. The results of the statistical evaluation indices divulge that the predicted wave reflection using the new formula is more accurate than the existing ones. Thus, it would be obvious that the present formula can provide a well-founded estimation of wave reflection on the MLBBs. Moreover, the new formula and those estimated by existing ones are validated by employing the data set exclusively used in drawing the comparison. This fair validation illustrates that the current formula is more accurate than the existing formulae.

Wave Reflection, Multi-layer berm breakwater, Experimental study, Prediction formula