抄録
More than 70 bridges were washed away by the Tsunami caused by the 2004 Off-Sumatra earthquake. 26 bridges were investigated and classified into three ranks as A, B, C according to the damage level.
In girder damage, 13 bridges (50%) were washed away by Tsunami, and the girder suffered the most extensive damaged member of among girder, substructure and embankment. Compared the damage rank with β value (the ratio between resistance of girder and tsunami force affected to the girder which assumed constant velocity (5.0m/s)), it was observed clear tendency between the damaged rank of girder and β value.
