The analysis of long wave diffractions due to offshore breakwater and seawall

The purpose of this study was to investigate the long wave-structure interaction that differs with varying incident wave period, length of offshore breakwater, and distance between offshore breakwater and seawall. The theoretical method was based upon the linear diffraction theory obtained by a pair of boundary integral approach. The water depth in the fluid region was assumed to be constant. To investigate the long wave interaction that was affected by offshore structure and seawall, a numerical program was developed, and the simulation was carried out by varying the conditions of the distance between two structures and length of offshore structures, and incident wave period. The results showed that various aspects of wave fields have been observed in accordance with conditions of geometric aspects. This study can effectively be utilized for safety assessment to various breakwater systems and layout of offshore breakwater in the ocean and coastal field. It can give safety information regarding the construction of offshore structure and seawall in coastal regions.   Key words: Long wave-structure interaction, boundary integral approach, offshore breakwater, seawall.