Experimental study on breakwater against overflow and high waves

摘要

In 2011, big tsunamis caused by the East Japan Earthquake attacked coasts with serious harms. If big waves had compounded with such huge tsunamis, the damage must have been more terrible. And, in recently years, big storms increasingly occur with significant disasters due to the climate change. Such a complex disaster may damage unexpectedly to coastal structures; nevertheless, the detail of the mechanism has not been studied sufficiently. Thus, in this paper, we performed hydraulic experiments, which target on the horizontal wave forces acting on a caisson and the mechanism of the suffering process of the armoring units, which cover the mound behind the caisson. From the results of the experiments, it is shown that the horizontal wave forces by the mixture phenomena increased comparing with that by only overflow in spite of the similar overflowing depth, which is defined by the sum of the overflowing depth and the one side wave height of the mixture phenomena. In addition, the experiments show the deteriorated suffering process of armoring units.