Masaru Yamashiro, Akinori Yoshida, Yasuhiro Nishii


At Waku fishing port, facing to Japan Sea, in Yamaguchi prefecture, Japan, a vertical type breakwater was constructed in front of the mouth of the port to protect the inside against incoming waves about 10 years ago. Residents in the area have been troubled with heavy seawater spray and much smaller sea salt particles caused at the breakwater by sever waves and strong winds ever since. To reduce the generation of and the damage from the seawater spray and the sea salt particles, three different types of measures were proposed: (a) covering the breakwater with wave dissipating blocks, (b) construction of a low crested offshore breakwater some distance ahead of the breakwater, and (c) construction of an artificial reef some distance ahead of the breakwater. Laboratory experiments using a wave flume with a wind tunnel were conducted to compare the effects of suppressing the water spray generation. The results of the comparative experiments showed that the covering with the wave dissipating blocks (Plan (a)) is the most effective means.


vertical breakwater; seawater spray; splash; wave dissipating blocks

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