Abstract
Concentrating on the Rikuzentakata area, which has suffered tremendous damages from Tsunami triggered by the Great East Japan Earthquake, the video and numerical analyses for simulation of tsunami have been conducted to understand the feature of tsunami including the wave type.
The tsunami wave running up the Kesen River was a bore wave with crest as around 2m; wherein, it is estimated that flow with the surface gradient in 1/100 primarily impacted on the superstructure of bridge after the wave crest went by. Further, the explanation for bridge outflow was succeeded by evaluating the tsunami impact force from the obtained flow velocity.
Additionally, via comparison to results of video analysis, it is concluded that good consistency occurred for the surface gradient of general wave shape. Whereas, the steep surface gradient has not been reappeared by numerical analysis for the reason that the ratio of flow velocity to wave velocity is not large enough during the raise of surface elevation.
