栓钉加强带脱空缺陷的钢管混凝土柱抗震性能试验研究

Test on seismic performance of concrete filled steel tube with circumferential gap reinforced by studs

为了研究环状脱空缺陷对钢管混凝土柱抗震性能的影响,设计制作3种不同内部构造的钢管混凝土柱,进行低周往复加载试验,研究环状脱空缺陷对钢管混凝土柱的破坏模式、滞回性能、水平承载力、转角延性系数、刚度和承载力退化以及耗能能力等的影响规律。结果表明:脱空缺陷显著降低了钢管对核心混凝土的约束效应,减弱了二者协同工作能力,致使柱的承载力和转角延性系数相较于无缺陷钢管混凝土柱分别降低了16.29%和33.03%;在钢管内布置栓钉能显著提高钢管对混凝土的约束效应,促进钢管与核心混凝土的协同工作,使具有脱空缺陷的钢管混凝土柱的承载力提高5.63%,而对转角延性系数的提高更为明显,达到了9.05%。同时,增设栓钉可以使环状脱空缺陷钢管混凝土柱的累积耗能提高15.19%。

In order to investigate the effect of circumferential gap on the seismic performance of concrete-filled steel tube(CFST)columns,three CFST column specimens with different internal configurations were designed.Low-cycle loading tests were conducted to study the influence of circumferential gap on the failure mode,hysteretic behavior,horizontal load-bearing capacity,rotation ductility factor,stiffness and strength degradation,and energy dissipation capacity of the CFST specimens.The results indicate that the gaps defect significantly diminish the constraining effect of the steel tube on the core concrete,weakening their collaborative capacity.Consequently,the bearing capacity and rotation ductility factor of the specimens decreased by 16.29%and 33.03%compared to concrete filled steel tube columns without gap,respectively;Studs inside the steel tube can significantly improve the constraining effect of the steel tube on the concrete,facilitating greater collaboration between the steel tube and the core concrete.This results in a 5.63%increase in the bearing capacity of CFST columns with circumferential gaps defects,while the enhancement in rotation ductility factor is more pronounced at 9.05%.Additionally,the incorporation of studs can contributes to a 15.19%improvement in the cumulative energy dissipation of the CFST column with circumferential gap defects.