Seismic fragility analysis of H shape pylon cable-stayed bridge considering soil-pile interaction

The current study is focused on seismic fragility analysis (SFA) to predict the seismic vulnerability of cable-stayed bridges (CSB) under uncertain seismic excitations considering soil-structure interaction (SSI). Seismic fragility curves (FC) exemplify the probable damage of CSB as a function of strong ground motions and can be used to evaluate the extent of damage probability for a certain ground motion index. This research utilised 25 ground motions to evaluate H-shaped pylon CSB in Indian Seismic Zone-V. The FCs have been developed using incremental dynamic analysis (IDA) for four performance criteria. The pylon DR and bearing displacement have been used to produce component FC. The traditional IDA approach is adopted, which involves linear regression. The bound limits have been derived using the first-order reliability theory. Analysis results prove that bearings are the most fragile component; their placements and hinge formulations significantly affect the system fragility.