不同构造多腔钢管混凝土巨型柱抗震性能试验研究

Seismic behavior of special-shaped multi-cell concrete-filled steel tubular mega-columns with different constructions

为研究不同构造的八边形钢管混凝土异形柱抗震性能,设计了4个1/30缩尺试件并进行低周反复荷载试验,从破坏特征、承载能力、滞回性能、刚度、延性以及耗能等方面分析其抗震性能。其中,四种截面构造包括13腔体基本构造、5腔体简化构造、角部角钢加强构造、角部圆钢管加强构造。试验结果表明：八边形异形截面钢管混凝土柱四种截面构造中,角部圆钢管加强试件抗震性能最好,角部角钢加强试件抗震性能其次,5腔体简化型试件和13腔体基本型试件承载力有较大差异,但5腔体简化型试件具有更好的延性,耗能能力差异不显著;试件屈服位移角均值为1/111,破坏时位移角均大于1/37,具有良好的延性。采用条带法计算试件承载力,计算值与试验值吻合良好。

In order to study the seismic behavior of special-shaped concrete-filled steel tubular （CFT） octagon section mega-columns with different configurations, four 1/30-scaled mega-column specimens were designed and tested under low-cycle reversal loading. Focus was given to their damage evolution behavior, hysteretic characteristics, bearing capacity, stiffness degradation, ductility, and energy dissipation. Four different section properties were considered, namely, basic configuration with 13 cells, simplified configuration with 5 cells, section strengthened with corner angle, and section strengthened with corner circular steel tube. The research shows that among the four different cross- section configurations, the one strengthened with comer circular steel tube shows the most favorable seismic performance, and the comer steel angle also leads to satisfactory behavior. The bearing capacity of the sections with 5 cells and 13 cells differs significantly, and the ductility of the former is better. In addition, the two configurations lead to similar energy dissipation. The average yielding drift ratio of specimens is 1/111, and the drift ratios at failure point of specimens are all larger than 1/37 indicating good ductility. The estimated load bearing capacity using strip method is shown to agree weli with the test results.