Life-cycle seismic resilience assessment of highway bridges with fiber-reinforced concrete piers in the corrosive environment

摘要

The benefit of fiber-reinforced concrete (FRC) to the life-cycle seismic performance of the bridge has not yet been fully studied. A probabilistic methodology was proposed in this study for the life-cycle performance assessment of deteriorating bridges constructed with FRC piers. The effect of the corrosive environment on the seismic performance of FRC bridges was evaluated under uncertainty through the seismic resilience analysis. The time-variant seismic capacity from different limit states was employed to estimate the functionality loss before the occurrence of the seismic event in order to improve the estimate of seismic resilience. A method was proposed to improve the accuracy of Cloud Analysis for the seismic fragility analysis, which was validated by the results of Incremental Dynamic Analysis (IDA). Seismic fragility analysis was then conducted by the improved Cloud Analysis based on numerical finite element models for simulating the behavior of FRC to obtain the reliable fragility estimates. The whole methodology in this paper was illustrated using a two-span highway bridge with conventional RC and FRC piers considering both diffusion process and seismic hazards. It can be concluded from the results that the FRC can improve the life-cycle seismic performance and resilience of highway bridges by around 25%. The performance benefit from the FRC can be underestimated if not considering the life-cycle effect. The improved Cloud Analysis is proved to be efficient and reliable in the seismic fragility analysis of bridges.