抄録
Xiaoyudong Bridge, a RC rigid-frame arch bridge, suffered enormous damage during the Wenchuan earthquake which occurred in China, on May 12th, 2008. Based on the field damage survey, the bridge structure was briefly summarized, as well as the ranked damage condition. Furthermore, dynamic analysis for Span 1 & 2 and Span 3 & 4 was conducted separately by using both E-W and U-D seismic waves. The damage condition of Span 1 & 2 were roughly well reappeared, while the possible collapse reason of Span 3 & 4 was verified. It was found that the damage of local members reduced the degree of static indeterminacy, which caused the gradual loss of entire stability. Consequently, these two spans collapsed into the river finally.
