一种可更换消能摇摆钢柱柱脚节点性能研究

Investigation on behavior of a replaceable energy-dissipative rocking column-base joint

介绍一种适用于双肢消能摇摆钢柱的可更换铰接柱脚节点构造及其静力试验研究。双肢消能摇摆柱是一种由两个钢柱肢及连接两柱肢的软钢系杆构成的结构构件,能够有效控制结构在地震作用下的侧向变形模式防止发生"薄弱层"破坏,并利用软钢系杆屈服耗能,进而提升结构整体的抗震能力。所提出的柱脚节点具有转动及抗拔能力,防止柱脚在侧向作用下产生弯矩而屈服,并抵抗两柱肢在侧向力产生的倾覆作用下引起的拉力。基于屈服线理论推导该柱脚节点的抗拔承载力计算公式,设计柱脚节点试件并设置平行试件,通过单调静力加载试验研究其实际受力行为及破坏模式,并基于有限元分析,验证承载力计算公式的准确性。试验结果表明,所提出的柱脚节点构造具有良好的抗拔承载力和延性,是一种满足可更换要求的铰接抗拔柱脚形式。

In this work, a kind of replaceable hinged joint of column base was introduced and investigated in the static test. The double-leg energy-dissipative rocking column is composed of two steel column legs and the soft steel tie rod connecting the two column legs. Hence, it can effectively control the lateral deformation mode of the structure under strong earthquakes, and thus preventing the occurrence of “weak storey” damage and use the yielding of soft steel tie rod for energy dissipation, resulting in the improvement on the overall seismic capacity of the structure. The developed column base joint has the ability of rotation and the uplift resistance, which may prevent the column base from yielding under the bending moment produced by the lateral action and resist the tensile force caused by the overturning of the two column legs under the lateral force. Based on the yield line theory, the calculation formula for the uplift bearing capacity of the column base joint was derived, and the specimens of the column base joint were designed for parallel tests. The actual mechanical behavior and failure mode of the specimens were studied by monotonically static loading test, and the accuracy of the calculation formula was verified by finite element analysis. The test results indicate that the developed column base joint has good uplift bearing capacity and ductility, and it can meet the requirement of replacement as a hinged column base with good uplift capacity.