A new type of wave control structure is needed in response to the seas which have little influx of wave energy from the open seas, have the relatively short-term incident-period, and have the relatively deep water levels, because they are surrounded with other islands. We can say that the appropriate structure which fits these conditions is the floating structure among many other structures. The floating structure is not only eco-friendly but also economical and it has the following advantages over the gravity structure ; 1) The inflow and outflow of the seawater is smoothly. 2)It doesn’t need the soil improving. 3) It is almost non-affected by the landscape variation or benthos around the structure. 4) It dosen’t need to be constructed on-site and it is easy to install and move. 5) Its section shape is diversified according to the field conditions. In Korea, there are some examples of installing the floating breakwater in Tongyeong(2007) and Wonjun Port in Masan City(2008) and there are many planning to install the floating breakwater in many surrounding seas of Korea in the near future.
In this study, a new type floating breakwater was proposed to improve the capability of wave attenuation compared with the existing floating breakwater in Wonjun Port, which is located in Masan City, Korea. In order to develop the optimal design, many different configurations considering the shape and location of vertical barrier and horizontal plate were examined based on the shape of existing floating breakwaters in Wonjun and Tongyeong Port.
The focus on discussions of development are the decrease of Reflection Coefficient and Transmission Coefficient in the same period. Wave deformation coefficient is applied with Source Distribution Method(SDM), and Numerical analysis is applied with Damped Wave Theory that can evaluate effectively damping effect of wave energy caused by formation of the friction and eddy from structure to evaluate more exactly wave control function. Performance of wave decrease of new type floating breakwater obtained from the foregoing development process was compared to the floating breakwater in Wonjun Port on condition of the same position and same arrangement shape, the characteristics of the new type floating breakwater was investigated. At this time, the analysis condition is as in the following; attacking waves are one-way irregular wave, period of attacking waves are period of design wave and the cases of longer than design wave’s period. As a result, new type floating breakwater can be confirmed effective performance of wave decrease more than Wonjun floating breakwater.
Three-dimensional motion analysis is calculated in variation characteristics of 6 Degrees of Freedom with use of 3D-SDM to apply the complex shape floating breakwater. As a result of the calculation of 6 Degrees of Freedom, distance estimation method of each floating breakwaters is confirmed for variation characteristics of Swaying and Rolling. and it is confirmed that non-dimension wave height distribution with use of 3D wave deformation caused by period variation of incident wave.