AbstractA flap-gate type movable seawall, which usually lies down on the ground, rises up automatically by buoyancy during inundation by tsunamis or storm surges, and then it forms a continuous seawall. This structure keeps lying in usual time to secure traffic and landscape. In emergence time, it protects a target area against inundation without power machineries and human operation. It is named NEORISE which means No Energy and no Operation RIsing SEawall, as shown in Figure.1.(Kimura 2014) The NEORISE system is equipped with counterweights hung by wire ropes connected with pins set on both sides of the top of a gate, inserting grooves of side-walls installed on both sides of the gate, through a pulley, and the counterweights assist the gate in rising and standing.(Kimura 2015) The counterweight reaches the lowest location in the middle of the gate's motion from the lying state to the standing state, and it works as an offsets to weight of the lying gate and as a brake for the moving gate just before standing.
Kimura, Mase (2014): Numerical Simulation of a Rising Seawall for Coastal Flood Protection, Journal of Waterway, Port, Coastal, and Ocean Eng., ASCE, Vol. 140(3), 04014002.
Kimura, Wakunaga, Yasuda, Kimura, Kani, Mase (2015): Development and Verification of Wall-Flap-Gate as an Inundation Defence for Nuclear plants, 23rd Structural Mechanics in Reactor Technology, Manchester, U.K.
Hirano, Kimura, Mizutani, Hiraishi, Mase (2016): Experimental study for feasibility and Response of Long-Span Type Flap-Gate Seawall against Tsunami Wave, Journal of Japan Society of Civil Eng., Ser. B3 (Ocean Engineering) Vol. 72(2), 682-687 (in Japanese).