EXAMINATION OF DAMAGE MITIGATION EFFECT USING MOVABLE BREAKWATERS BY TYPHOONS

Abstract

 In this study, the effectiveness of the movable breakwaters for reducing the water level and preventing storm surge was investigated at Tokyo Bay under the worst-case scenario based on an empirical typhoon model. As a result, the water level reduction effect of the movable breakwaters at the harbor was 11.2-42.2 % for each installation and 27.4-45.7 % for multiple installations in the typhoon path where the maximum stormsurge was observed. In addition, it was found that the multiple installation of the system was effective for reducing the water level in the river, while the installation of the system only at the mouth of the river was sufficient to prevent stormsurge. In addition, a comparison the method of raising the levee, conventional strengthen-ing, and the movable breakwaters on the inundation control effect showed that the movable breakwaters was more effective than the method of raising the levee uniformly by 3.0 m in the case that install multiple breakwaters in the harbor and in the river.