Introducing a Hybrid Isolated-Rocking Precast Concrete Segmental Bridge Column: Quasi-Static Analysis and Performance Evaluation

This research introduces an innovative hybrid isolated-rocking (HIR) bridge column and investigates its performance using numerical simulations. The proposed column consists of precast concrete segments with end rocking joints, lead rubber bearings (LRBs) at intermediate joints, and internal unbonded post-tensioning tendons. Such a configuration is intended to provide HIR columns with low-damage energy dissipation and self-centering capabilities. An iterative displacement-based methodology is used for the seismic design of bridges with HIR columns. This method considers all design variables and directly incorporates the nonlinear response of the system. To evaluate the performance of HIR columns under monotonic and cyclic quasi-static loading, a nonlinear three-dimensional continuum-based finite-element (FE) model is developed in Abaqus. The modeling method is validated using the available experimental data for hybrid sliding–rocking (HSR) columns. The FE model is utilized to examine the potential effects of protective steel plates, initial post-tensioning force, and gravity loads on the response of HIR columns. The reference HIR column exhibits a stable hysteretic response with equivalent viscous damping ratios up to 17% for drifts below 4%. The residual drift of the examined HIR column remains below 0.7% and is reversible. This indicates the column’s strong self-centering capabilities. Due to the presence of bearings in the HIR column, rocking does not occur at low drift levels. As a result, the column remains practically undamaged even under the maximum considered earthquake (MCE) displacement demands.