Numerical simulation of nonlinear interaction between floating thin-plates and surface waves has been performed to study the reduction of tsunami height due to propagation of tsunamis through very large floating structures (VLFS). When a solitary wave propagates through a floating thin-plate, wave disintegration occurs, resulting in generation of short floating-body waves, such that the wave height of the main wave is decreased. While the main wave is combined with the short waves after progressing through the thin-plates, the wave height of the main wave is increased. Once the main wave passes the short waves, its wave height decreases, which indicates that a VLFS is applicable to reduce tsunami height. The reduction effect depends on both the length of floating structures and the interval of the structures.
