Seismic performance of PS-CFST bridge piers with novel external replaceable energy dissipating devices

This study proposed a novel external replaceable energy-dissipating device (EREDD) to enhance the seismic performance of prefabricated segmental concrete filled steel tubular bridge piers (PS-CFST bridge piers), while maintaining the construction efficiency of conventional segmentally assembled prefabricated piers with dry joints. The effectiveness and applicability of EREDDs in improving the seismic performance of PS-CFST bridge piers were studied through the cyclic tests. The inelastic cyclic response of PS-CFST bridge pier specimens with different arrangements of EREDDs was experimentally examined. A detailed account of the test results was provided and discussed, including the stiffness and strength characteristics, strain distributions, residual displacements, failure patterns, as well as hysteretic response and energy dissipation capability. Particular attention was also given within the experimental assessment to investigating the effects of the inter-segmental joint opening positions for the different EREDD arrangements on the seismic response of PS-CFST bridge piers. Based on the experimental findings, an analytical approach was developed for determining the hysteretic response of the proposed PS-CFST bridge piers incorporating EREDDs, offering the basis for their design and assessment in practice. Finally, the results indicate that EREDDs could effectively improve the seismic performance of PS-CFST bridge piers and the hysteretic response could be accurately predicted by using the proposed analytical approach. In addition, EREDDs allow the damage of PS-CFST bridge piers to be concentrated within the easily replaceable component, and thereby facilitating the controlled damage. This study provides an effective method for the seismic design of PS-CFST bridge piers incorporating EREDDs.