2008 年 24 巻 p. 51-56
It is concerned that indirect damages due to tsunami like collisions of drifted objects such as boats, automobiles. containers, etc. are severe as well as direct damages. To predict and reduce these kinds of damages, the characteristics of drifted container are experimentally investigated with installing different types of structures on the apron. As a result, it is found that in case a sea wall is installed, drifted container has less possibility to collide sea wall because water between the container and sea wall is working as a buffer. On the other hand, there is good possibility for the container to be drifted to offshore and fall down. The wave force acting on the fixed container can explain well the mechanism of this phenomenon. Moreover, it is found that in case rectangular finite structure is installed, drifted container would flow away beyond the structure due to long period wave.