抄録
This paper deals with how tsunami force acted on bridge girders when the Great East Japan Earthquake broke out on March 11, 2011. First of all, almost all data of bridge girders in the inundation area were collected. Satellite images in internet websites were introduced to make a quick survey on how many bridges were in the inundation area and how many of them were damaged. Detailed data on the bridges, such as dimensions and types, were obtained from authorities that have maintained those bridges. For damage analysis of bridge girders, Prof. Kosa's method was introduced to see whether bridges were washed away or not by tsunami. Motion pictures of the tsunami taken by residents when it happened were examined to evaluate the velocity and height of the tsunami. In order to examine how bridge girders were washed away, an experimental investigation was conducted using a big water channel. Hydrodynamic analysis was conducted to evaluate the test results. In addition, a new numerical simulation technique was developed to follow the movement of a bridge girder during the tsunami.
