Bài báo khoa học

The purpose of this paper is to investigate the influence of typical parameters on seismic fragility curves of reinforced concrete (RC) piers of continuous steel box girder bridges. Typical parameters considered include the pier heights, pier section types, and total length of bridges. Twenty recorded ground motions from historic seismic events are randomly selected for fragility analyses. The finite element analysis program, OpenSees, is employed to perform nonlinear dynamic analyses of the bridges. A set of damage states of bridge piers is proposed based on the damage index, which is based on the drift ratio of the pier. Fragility curves of piers are eventually generated using maximum likelihood estimation. The numerical analysis results show that the bridges with shorter piers are less vulnerable to earthquakes than those with higher piers. Moreover, the wall pier types have significantly improved seismic performance compared with the other types. The fragility analysis results also reveal that the total bridge length has notably affected to seismic response of bridges.