2012 Volume 68 Issue 2 Pages I_246-I_251
The flap-gate seawall usually lies down on ground surface and rises up in buoyancy against inundation due to tsunamis or storm surges. It needs neither power machineries nor human operations, and perfectly protects a target important area against the inundation. In the Tohoku earthquake tsunamis, serious damages were caused by inundation from mouths of outer walls in several large buildings. The present study verifies both capability of disaster prevention and characteristics of hydrodynamics of the wall-attached type flap-gate in a series of hydraulic model experiments employed in a 50m wave channel. The experimental results demonstrate that the flap-gate type seawalls rise up immediately and prevent the inundation from openings. Moreover, characteristics of wave pressure induced in bore-type tsunamis were evaluated and the data necessary for prototype design was obtained.
