The video and numerical analyses were conducted to investigate the tsunami characteristics in Kamaishi Area, damaged by the tsunami due to Great East Japan Earthquake. From field survey, although the Yanoura Bridge girder was affected by tsunami, it was not washed away. The surviving reason was evaluated by the flow velocity obtained by numerical analysis. As a result, it was found that because the flow velocity acting on the bridge girder was relatively slow, which was 4.0m/s the bridge girder survived. Furthermore, the tsunami numerical analyses with or without coastal breakwater were conducted, and comparing their results, it was known that both of flow velocity and inundation height became small, because of the resistance of breakwater.
