The present study investigates the seismic fragility of a six-tower cable-stayed bridge and delves into the influence of different structural system types on this bridge. SeismoStruct software is applied to establish the numerical model of a six-tower cable-stayed bridge, and its accuracy is verified through a shaking table test. Then, the seismic fragility curves of this bridge are generated through incremental dynamic analysis to assess its seismic performance under longitudinal earthquakes. Then, the impact of the different structural system types (the number of towers and the girder–pier connection form in the longitudinal direction) on the seismic fragility of the cable-stayed bridge is analysed. The results show that the fixed bearing is the most vulnerable component, and the middle pier is greatly threatened by earthquakes. With the decrease in the number of towers, there is a slight impact on the seismic fragility of the fixed bearing, and the middle pier is no longer the most vulnerable bridge pier. Moreover, the damage sequence of different components in the six-tower cable-stayed bridge is changed in the longitudinal consolidated structural system. The damage probability of the transition and the side piers is greater than that of the middle pier.
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