Seismic fragility assessment of a three-tower cable-stayed bridge based on OpenSees platform

With the upgrading of urban planning and construction, resilient city construction has gradually become an important proposition to promote urban sustainable development. Resilient disaster prevention is its main content, in which the seismic resilience of lifeline bridge is particularly important. This paper conducts the seismic fragility analysis of a three-tower cable-stayed bridge to assess its seismic performance and facilitate the subsequent seismic resilience evaluation of the cable-stayed bridge. The finite element model for the bridge is established using OpenSees platform. The fragility curves of the main components of the bridge are established by adopting the fragility model based on incremental dynamic analysis (IDA), and the fragility of the whole bridge is evaluated using the narrow bound method. The results show that the tower is the most fragile component, while the failure probability of the cable is relatively low. The failure of the whole bridge is mainly determined by the tower.