Precast concrete column base with replaceable energy dissipation connectors: Quasi‐static tests and numerical research

A type of precast concrete column base with replaceable energy dissipation connectors (REDCs) is proposed in this study. The bottom of the column is reinforced with a square steel tube. REDCs can transfer the bending moment of the column base during frequent earthquakes and yield to dissipate most of the inputted seismic energy during major earthquakes. Several raised steel stoppers are arranged around the sides of the column base to limit lateral slippage. The load-resisting mechanism, construction technology and post-earthquake repair methods of the column base are introduced. Five quasi-static tests were carried out on a full-scale test specimen, in which the experimental variables include the axial compression ratio of the column and the size of the REDCs. The test results show that the damage was concentrated in the REDCs while the precast column suffered minor damage. The REDCs fractured after dozens of cycles at large lateral drift ratios, effectively exerting their excellent low-cycle fatigue performance. Plump and stable hysteretic curves and bilinear skeleton curves were obtained in test results. The curves before and after seismic rehabilitation are similar. Furthermore, a simplified numerical analysis model of the column base is established using OpenSees. The hysteretic curves and skeleton curves obtained by simulation agree with the test results.