Seismic fragility and life‐cycle loss analyses of high‐speed railway bridges supported by segmentally assembled round‐end hollow piers

Abstract

The shortcomings of segmentally assembled round‐end hollow‐section piers (SRHPs), such as weak segment joints and poor energy‐dissipation capacity, have limited their application in high‐intensity earthquake regions. Therefore, this article particularly focuses on the seismic performance of SRHPs. Three high‐speed railway bridges are designed, which are equipped with three different types of round‐end hollow‐section piers (RHPs): cast‐in situ RHP (CRHP), segmentally assembled RHP with energy‐dissipation bar (E‐SRHP), and segmentally assembled RHP with low‐yield point steel connection buckles (L‐SRHP). Subsequently, three nonlinear finite element models of the corresponding bridges were established and validated by quasi‐static test results. Furthermore, compared to CRHP, the seismic performance of E‐SRHP and L‐SRHP was evaluated from the perspectives of seismic fragility and life‐cycle seismic loss. Research results revealed that the seismic fragility performance of the bridge with L‐SRHP is the best among all three bridges, followed by the bridge with E‐SRHP. Notably, the life‐cycle cost considering seismic loss for E‐SRHP is 83% of that for CRHP, whereas L‐SRHP is only 65% of that for CRHP. In general, the high‐speed railway bridge supported by L‐SRHP possesses the best seismic performance and economic benefits among the three bridges, which shows promising application prospects in high‐intensity earthquake‐prone regions.