内衬管螺纹连接中空圆钢管混凝土的轴压性能实验

Test on compressive performance of hollow concrete-filled circular steel tube connected by thread through lined tube

提出采用内衬管和螺纹连接方式连接长圆钢管混凝土。以螺纹的长度、深度和位置为基本参数设计12个内衬管螺纹连接中空圆钢管混凝土短柱,并进行轴压试验,分析不同参数对试件轴压承载力和刚度的影响。结果表明,试件的轴压力-纵向压缩量曲线可以划分为弹性阶段、弹塑性阶段和下降段。内衬管螺纹连接试件的承载力和刚度与无连接试件或者焊接试件基本持平。在本文的研究参数范围内,端截面内衬管螺纹连接试件的承载力和刚度均高于中截面内衬管螺纹连接试件,试件的承载力和刚度随着螺纹长度与深度的增加而增大。依据理论计算结果与实验结果的对比,给出内衬管螺纹连接圆中空钢管混凝土轴压承载力计算方法的建议。

A method of lengthening the steel tube of concrete-filled circular steel tube by lined tube and threaded connection is proposed.Taking the length,depth,and position of the thread as the basic parameters,12 hollow concrete-filled circular steel tube specimens connected by thread through lined tube are designed,and the axial compression test is carried out.The axial loading-displacement curves,axial loading-strain curves,and failure mode of the specimens are analyzed,and the effects of different parameters on the axial compressive bearing capacity and stiffness of the specimens are studied.The results show that the axial loading-displacement curves of the specimen can be divided into the linear elastic stage,plasto-elastic stage and descending stage.The bearing capacity and stiffness of the specimens connected by thread through lined tube are basically the same as those of the unconnected specimen or the specimen welded.In the range of parameters studied of this paper,the load capacity and stiffness of the specimens connected at the end section by thread through lined tube are higher than those of the specimens connected at the middle section by thread through lined tube,and the bearing capacity and stiffness of the specimen increase with the increase of thread length and depth.Based on the comparison between the calculation results calculated by existing formulas of the axial compressive bearing capacity of hollow concrete-filled circular steel tube and the test results of specimens connected by thread through lined tube,the suggestions on the calculation method of the load capacity of hollow concrete-filled circular steel tubes connected by thread through lined tube are proposed.