The objective of this paper is to develop the fragility curves of a highway bridge through incremental dynamic analysis using ground motion data of near-fault and far-field earthquke. Both quasi-static and dynamic pushover analyses are performed to achieved capacity of the pier and the bridge. Near fault earthquake ground motion data from 1999 Chi-Chi earthquake and far field earthquake data from same sites are served as input ground excitations to evaluate the vulnerability of a typical five-span continous post-tension concrete box grider bridge in Taiwan..
The fragility curves with corresponding damage states of the bridge are related to the intensity measures of PGA. The comparison of fragility curves of this five-span continous post-tension concrete box grider bridge
in Taiwan and HWB20(conventional design) and HWB21 (seismic design) in HAZUS99 is also conducted.