外置连接钢板强度对节段拼装CFST桥墩抗震性能的影响试验研究

Experimental study on the seismic performance of precast segmental CFST piers considering the strength of external links

摘要:

为使桥梁下部结构在地震过程中减少损伤且震后可实现快速修复,基于可恢复功能结构设计理念,提出一种设置有外置耗能连接件（EREDL）的预制填充的钢筋混凝土（PSCFST）桥墩,并针对设置不同强度EREDL的PSCFST桥墩试件进行水平低周往复拟静力加载试验。试验结果表明,EREDL可实现预期的作用效果,且Q355强度的EREDL抵抗变形的能力更强;通过对比分析，两组桥墩的滞回性能、耗能能力、残余位移以及退化刚度,发现在5%的偏移率范围内EREDL强度的提升会降低桥墩的承载力,并增大桥墩的残余位移。研究成果可为节段预制拼装桥墩的设计和抗震性能优化提供重要参考。

Abstract:

To reduce the damage and loss of bridge substructure during earthquakes, avoid casualties, and achieve rapid repairs after earthquakes, this study proposes an external replaceable energy dissipating links (EREDL)-precast segmental concrete-filled steel tubular pier based on the structural design concept of resilience. EREDLs with different levels of strengths were set at the joints of two groups of piers, and quasi-static tests were conducted on the piers under horizontal low cyclic loadings. Upon comparing the deformation of the two groups of piers, the results show that EREDL with Q355 strength is more resistant to deformation. Furthermore, a comparative analysis of the hysteretic curves, energy dissipation capacity, residual displacement, and degradation stiffness of two groups of piers reveals that the increase of EREDL strength within the range of 5% offset rate reduces the bearing capacity and increases the residual displacement of the pier. Overall, the research results can provide an important reference for the design and seismic performance optimization of precast segmental bridge piers.