Abstract

This paper aims to explore the seismic performance of a novel earthquake-resilient bridge column with replaceable elements, including external ultra-high-performance concrete (UHPC) cover plates and internal steel dissipaters, based on a numerical model including local and overall levels. The overall model was established to assess the seismic behavior of the bridge columns considering the buckling behavior of steel dissipaters adopting the modified material constitutive relationship, of which the parameters were determined according to the results of the local model. The numerical model was verified with reported experimental results. A parametric analysis was conducted to investigate the effects of three parameters. The results show that the numerical model can effectively evaluate the seismic performance of the bridge columns. The buckling behavior of steel dissipaters dominates lateral deformation capacity of the bridge columns. The steel dissipater's initial defect direction and gap gradient can accelerate the failure of cover plates. Reasonable upper and lower limits are required for the length-to-diameter ratio of the fuse part as well as the gap between the fuse part and surrounding concrete, while only a suitable lower limit is needed for the thickness of cover plate to ensure the superior seismic performance of the bridge columns.

摘要

本文旨在基于包括局部和整体水平的数值模型，探索具有可更换构件的新型抗震桥柱的抗震性能，包括外部超高性能混凝土 (UHPC) 盖板和内部钢耗能器。采用改进的材料本构关系，建立考虑钢耗能器屈曲行为的桥梁柱抗震性能评估整体模型，其参数根据局部模型的结果确定。数值模型用报告的实验结果进行了验证。进行参数分析以研究三个参数的影响。结果表明，该数值模型可以有效地评价桥柱的抗震性能。钢耗能器的屈曲行为支配着桥柱的横向变形能力。消能器的初始缺陷方向和间隙梯度会加速盖板的失效。熔断器的长径比以及熔断器与周围混凝土的间隙要求合理的上下限，而盖板的厚度只要有一个合适的下限，就可以保证优良的性能。桥梁柱的抗震性能。