Experimental study and numerical model validation on seismic performance of self-centering precast segmental bridge columns

Self-centering precast segmental bridge columns (SC-PSBCs) have emerged as a promising solution for achieving rapid construction and post-earthquake reparability. However, experimental investigations identifying the key factors governing their seismic behavior remain limited. This study conducted a systematic experimental investigation on SC-PSBCs. Eight specimens, including one monolithic bridge column (MBC) and seven SC-PSBCs, were designed and tested under quasi-static cyclic loading to examine the effects of four parameters: structural type, energy-dissipating (ED) bar ratio, post-tensioned (PT) tendon ratio, and concrete strength. The MBC exhibited full hysteresis loops, indicating superior lateral load-bearing capacity and energy dissipation, although it experienced a residual displacement approximately 44.9 times that of the SC-PSBCs without ED bars. In contrast, the SC-PSBCs without ED bars showed a flag-shaped hysteresis, reflecting excellent self-centering capability but limited energy dissipation, about 93.4% lower than that of the MBC. Introducing ED bars effectively enhanced energy dissipation by 164.0% and lateral load capacity by 11.4% but increased residual displacement by 13.9 times when the ED bar ratio rose from 0% to 0.91%. Increasing the PT tendon ratio from 0.54% to 1.63% improved peak lateral load capacity by 34.1% but raised residual displacement by 66.8%. Employing higher-strength concrete elevated lateral capacity by 43.1% and energy dissipation by 149.7%, but led to an 80.6% increase in residual displacement as the strength rose from 40 MPa to 130 MPa. Furthermore, a refined finite element model was established and validated, providing a reliable basis for seismic performance prediction of SC-PSBCs.