Seismic Response of Baihua Viaduct during the Wenchuan Earthquake and Methods of Reducing Seismic Damage

Baihua Viaduct which is an important transportation project of 213 National Highway was severely destroyed during the 512 Wenchuan earthquake. The fifth segment of the bridge suffered the most severe unrepairable damage, such as the rupture of the piers and falling of beams. It is worth to study the performance through the FEM dynamical analysis to explain the damage performance of Baihua Viaduct in the earthquake. The dynamical FE model of the Baihua Viaduct is established considering the non-liner properties of piers and bearings. Further the earthquake records of the nearest Wolong station is chosen to be as the earthquake excitation input to conduct the seismic analysis. The analysis shows that the results of damage position and damage degree of components of the bridge calculated by elastic-plastic dynamic analysis are close to the actual damage of Baihua Viaduct. The reinforcement ratio of piers is low, while there is not any shear failure on piers. The damage degree of elastic hinge is related with the arrangement of bearings. The girders’ displacement is much larger because there are not any anti-dropping devices on the bridge. Damage of the fifth segment of bridge may be caused by plasticity destroy of some piers.