（1 湖南大学土木工程学院， 长沙 410000； 2 工程结构损伤诊断湖南省重点实验室， 长沙 410000）

［摘要］为提高钢管混凝土长柱的稳定承载能力以及抗震性能，采用在长柱周边增加分肢柱的组合结构形式，对比研究了轴压作用下的组合柱受力性能，完成了两个分肢组合柱试件的轴压试验，即灌混凝土组合长柱与未灌混凝土组合长柱试件。试验过程中主要获取了组合柱的承载能力、破坏形态、内力分布等数据。试验结果表明，采用分肢组合柱可以显著提高钢管混凝土长柱的稳定承载能力，其极限承载能力由强度控制，周边分肢柱分担了约50%的竖向荷载；灌混凝土组合长柱的整体受力特性显著改善，极限承载能力大幅提高，且在轴压作用下最终破坏由上部单柱控制。基于试验结果，结合稳定理论基本原理，将组合柱简化为一变截面柱进行稳定承载能力计算，并对上柱长度、下柱长度、下柱层数等因素对组合柱承载能力的影响进行了探讨。

［关键词］钢管混凝土； 长柱； 分肢组合柱； 轴压稳定性； 稳定计算

中图分类号：TU311-2, TU392文献标识码：A文章编号：1002-848X(2018)19-0065-06

Experimental study on axial compression stability performance of concrete filled steel tube columns

Yang Xiao1， He Qingfeng1，2， Liu Yiren1， Yi Weijian1，2

(1 Department of Civil Engineering, Hunan University, Changsha 410000, China；2 Hunan Key Laboratory of Engineering Structure Damage Diagnosis, Changsha 410000, China)

Abstract:In order to improve the stability bearing capacity  and seismic performance of concrete filled steel tubular long columns, a composite structure with splitting columns around the long column  was adopted.  The axial compression tests of two split combined columns were completed, including the steel tubular long column filled with concrete and the column without concrete. The load bearing capacity, failure mode and internal force distribution of the composite column were obtained in the experiment. Test results show that the split combined column proposed  can significantly improve the stability bearing capacity of concrete filled steel tubular long columns and its ultimate bearing capacity is controlled by the strength, and about half of the vertical load is shared by the peripheral limb columns. The overall mechanical performance of the combined long column filled with concrete is significantly improved and the ultimate bearing capacity is greatly improved. Besides, the ultimate failure of the composite columns under axial compression is controlled by the upper single column. Based on the experimental results, combined with the basic principle of stability theory, the composite column was simplified into a variablesection column for the calculation of the stability bearing capacity, and the influence of the factors such as the length of the upper column, the length of the lower column and the number of the lower column on the bearing capacity of the combined column were discussed.

Keywords:concrete filled steel tube; long column; split combined column; axial compression stability; stability calculation

*既有工业建筑非工业化改造技术研究（2016YFC0701308）,国家自然科学基金(51108170)，中央高校基本科研业务费资助。

通讯作者：何庆锋，博士，高级工程师，Email：5672101@qq.com。