Advancements in fragility analysis using numerical calibration methods for a horizontally curved RC bridge

Horizontally curved reinforced concrete (RC) bridge piers are subjected to combined actions of axial, shear, bending and torsion. The interaction between these combined forces in the highly inelastic range significantly influences the response of the bridge piers. In this paper, a three-dimensional fiber-based finite element model of a curved bridge is developed. The model is then calibrated based on experimental data. The calibration process is conducted with the objective of developing a computationally inexpensive model that can accurately mimic the response of bridge piers subjected to complex multi-directional earthquake loading conditions. An evaluation of the seismic fragility relationships of a curved bridge is undertaken using the initial (un-calibrated) and calibrated numerical models. The results from both models indicate that combined forces interaction significantly affect fragility relationships.