It had been reported that many bridges in Sumatra island were suffered serious damages due to the 2004 Indian Ocean Tsunami event. We conducted the propagation and runup simulation of tsunami to clarify the external force acted on the bridges of the neighborhood of Banda Aceh. Numerical results showed that the horizontal tsunami force at Cut River Bridge and Lueng Ie Bridge were much larger than that of Kr. Ritting Bridge. A Safety Factor (S.F.), which could predict whether the girder slide occurred or not, was evaluated for the three bridges. The S.F. value was able to identify a clear difference in correspondence with the damage situation of each bridge. A present method is very simple, but it is applicable for the tsunami damage prediction of a bridge.
