Experimental and numerical investigations of the seismic behavior of socket and hybrid connections for PCFT bridge columns

The present paper investigates an innovative seismic-resilient bridge column-footing socket connection (SC) for post-tensioned concrete-filled steel tube (PCFT) columns defined according to the Accelerated Bridge Construction (ABC) requirements. PCFT-SC column uses embedded dissipate seismic energy and unbonded (PT) bars improve self-centering capacity. Experimental tests were performed on a column, response was compared with PCFT hybrid (HC) previously investigated by authors. experimental confirmed that could develop large strength, stiffness, ductility capacity that, PCFT-HC its performance is competitive drifts up 2.8%. For larger drifts, performances are slightly reduced due local buckling resulting PT force loss. However, even in these cases, be preferred constructional advantages. Simplified models of SC HC developed OpenSees, including modeling details accounting effects numerical results, calibrated against data, showed importance considering loss cyclic load analysis columns.