Experimental and numerical investigation on post-tensioned prefabricated RC bridge column with replaceable buckling-restrained energy dissipaters

To achieve concentrated and easily repairable structural damage after earthquakes, the post-tensioned prefabricated RC bridge column with replaceable buckling-restrained energy dissipaters (PPBC-RBED) was proposed. The assembly connection between the prefabricated bridge column and foundation was achieved through post-tensioned unbonded prestressing and welding of replaceable buckling-restrained energy dissipaters (RBEDs). The square steel tube at the bottom of the pier effectively enhanced the vertical load-carrying capacity and prevented local crushing of concrete. The friction in the compressed area at the pier bottom and the additional raised limiting bars jointly resisted the horizontal shear force. Low-cycle reversed loading tests were conducted under various test conditions to investigate the seismic performance, including the hysteresis behavior, failure mode, energy dissipation capacity, and residual displacement, by varying the initial post-tensioned force and thickness of energy-dissipating plate (EP) in the RBED. The experimental results showed that the PPBC-RBED demonstrated excellent seismic performance and utilized the outstanding energy dissipation capability of the RBEDs. The damage of PPBC-RBED were mainly concentrated in the RBED. The seismic performance of the PPBC-RBED remained essentially consistent before and after replacement, validating the feasibility of post-earthquake repair. A refined finite element model (FEM) of the PPBC-RBED was established using ABAQUS. The hysteretic response and damage pattern obtained from the numerical simulations under various test conditions closely aligned with experimental results, verifying the accuracy of the FEM and confirming the deformation characteristics of damage concentration. Additionally, the hysteretic behavior, stress distribution, and buckling pattern of the EPs were analyzed. The yield section of EP exhibited a significant multi-wave buckling pattern, with the measured buckling waves closely matching the simulation results and theoretical values.