Hysteretic modeling of unbonded posttensioned precast bridge columns with circular section based on cyclic loading test

The seismic performance of unbonded posttensioned (PT) precast segmental bridge columns (PSBCs) with circular sections was investigated. Two precast segmental columns with/without energy dissipation (ED) bars were tested under quasi-static cyclic loading. Their damage patterns and hysteretic curves were compared. Three single-degree-of-freedom hysteretic models were formulated with the key parameters identified from the tests. Cyclic loading analyses of the two tested specimens were conducted using these hysteretic models. Time history analyses were also conducted utilizing the proposed three hysteretic models to observe their applicability in modeling the dynamic responses of PSBCs. Finally, parametric analyses of PSBCs were performed under the excitation of an ensemble of 20 history ground motions to study the influences of relative yield force, elastic period, and energy dissipation coefficient on the earthquake responses of displacement ductility demand, maximum absolute acceleration, and maximum absorbed energy.