Reliably Predicting the Nonlinear Cyclic Response of RC Bridge Piers up to Complete Collapse

In this paper, an advanced modelling technique is developed to predict the nonlinear cyclic response of circular RC columns using a new phenomenological hysteretic model for reinforcing bars. The model has been implemented in OpenSees and is intended to be used in conjunction with a nonlinear fibre beam-column element. A comparison between different reinforcing steel models is made. Through a comprehensive parametric study, the influence of inelastic buckling of vertical reinforcement on the cyclic response of circular RC columns is investigated. The results have been compared and validated against a set of experimental datasets. The proposed calibrated model accounts for the influence of inelastic buckling of vertical reinforcement, stiffness of horizontal ties and their interaction with vertical reinforcement, and fracture of vertical bars due to low-cycle fatigue on cyclic degradation of circular RC columns.