It is important to evaluate the damage on structures due to the drifting bodies with tsunami. However drifting behavior is very sensitive to tsunami velocity and its force. The purpose of the present study is to investigate the variability in the drifting bodies due to tsunami. First, experimental tests are carried out. As a result, tsunami turbulent diffusivity that occurred by breaking waves was related to variability in drifting behavior. Second, calculation is carried out using the diffusion coefficient provided by the experiment. Finally, an evaluation method is proposed which can predict the behavior of drifting bodies by tsunami.
