EXPERIMENTAL STUDY ON TSUNAMI COASTAL DIKE IN AIR BAG STRUCTURAL TYPE

In this study, tsunami resistance performance for a tsunami coastal dike of air bag structural type which can be stood with air expansion has been inspected through some experiments. Relatively small tsunami when flooding on the land is targeted, whereas full-scale experiments have been executed in an underground tank. The tank is separated by a wall on a reveal part of which test dike material is installed and water is poured in the front side of the test dike surface to exert the hydrodynamic pressure imitating the tsunami design pressure distribution and to measure strain, displacement and inner pressure change of the membrane surface. It is necessary to remark that air compression and inner pressure raise on tsunami may cause material deformation and back side membrane surface movement intermediated by air pressure change, and membrane strain variation with initial inner air pressure also cause material distortion. On the other hands, pressure raise inside the air bag mitigates membrane distortion in the front surface of the structure which will improve tsunami resistance performance of the proposed dike.