PERFORMANCE OF CONCRETE PONTOON FLOATING BREAKWATER WITH DOUBLE CONFIGURATION

Abstract

Development of floating breakwater are increasing along with the rising interest of floating infrastructure. One of the applications is floating breakwater using concrete pontoon. Large and rigid structure are possible to construct with the usage of concrete. However, it still limited with the available construction and transportation method to handle such a large structure. Double configurations of floating breakwater proposed to increase the structure’s performance with the size limitation. The breakwater performance tested with physical model in laboratory by comparing performance of single pontoon with double pontoon for various structure spacing. Pontoon size are 1.2 m in length, 0.3 m in width, and 0.15 m in height and tested with many combination of irregular waves and for double configurations model, the spacing of 30 cm, 60 cm, and 90 cm are used. The structure works optimal in low range harmonic period. Performance of single configuration are in the range of Kt 0.6 up to 0.97, transmission increased along with the waves period. The Kt value of double configuration are around 0.45 up to 0.8. Performance of double configuration determined by ratio of structure spacing with wavelength. Larger ratio resulted a better performance in condition where the spacing did not exceed 0.65 length of wavelength.