竖向荷载作用下插接式Y形钢管混凝土转换节点的承载力试验研究  

Experimental study on the bearing capacity of Y-shaped concrete-filled steel tubular joints with plug-in connection under vertical load

作　　者：赵小芹 左志亮[2] 陈庆军[2] 蔡健[2] 刘达鑫 ZHAO Xiaoqin;ZUO Zhiliang;CHEN Qingjun;CAI Jian;LIU Daxin(School of Civil Engineering,Guangzhou City University of Technology,Guangzhou 510800,China;School of Civil and Transportation Engineering,South China University of Technology,Guangzhou 510641,China;Guangzhou Design Institute Group CO.LTD.,Guangzhou 510620,China)

机构地区：[1]广州城市理工学院土木工程学院,广东广州510800 [2]华南理工大学土木与交通学院,广东广州510641 [3]广州市设计院集团有限公司,广东广州510620

出　　处：《建筑结构学报》2023年第2期16-26,共11页Journal of Building Structures

基　　金：国家自然科学基金项目(51408230);广东省自然科学基金项目(2022A1515011115);广东省普通高校青年创新人才项目自然科学类(2018KQNCX370);广州市科技计划项目(201610010077)。

摘　　要：为实现不同截面形式的斜柱与支柱的可靠连接,提出一种Y形钢管混凝土转换节点,其双斜柱和支柱采用插接式连接。以斜柱钢管壁厚、支柱直径、斜柱插入深度以及斜交区是否设置加劲肋为参数,设计8个双肢方形截面斜柱和圆形截面支柱转换节点,通过竖向荷载下的静力试验,研究其破坏模式、承载力、变形特点和受力机理。研究结果表明:在竖向荷载作用下,插接式节点的核心区能有效传力,其顶面承受局部压力作用,局部压力扩散范围延伸至支柱;斜交区混凝土受约束作用大,对该区域的变形和承载能力有利;斜柱插入深度是影响节点受力性能的关键参数,随着插入深度的增加,节点承载力最大提高18%,钢管首先达到屈服应变和发生局部屈曲的部位改变;斜交区设加劲肋能够提高斜交区的刚度和承载力,使薄弱位置转移。基于试验获得的节点各区域受力特征,提出适用于双肢方形截面斜柱与圆形截面支柱插接式Y形转换节点在对称竖向荷载作用下的承载力计算公式。承载力计算结果与试验结果之比的平均值为0.879,标准差为0.049,计算结果偏安全,离散性较小。To achieve a reliable connection between inclined columns and the supporting column with different cross-sections, a Y-shaped concrete-filled steel tubular(CFST) transfer joint was proposed, in which the double inclined columns and the supporting column were connected by a plug-in connection.Taking the steel tube thickness of the inclined columns, the diameter of the supporting column, the inserted depth of the inclined columns, and whether stiffening ribs were set in the intersection zone as parameters. Eight specimens of transfer joints with double square CFST inclined columns and a circular CFST supporting column were designed.The tests were conducted under vertical load.The failure modes, bearing capacity, deformation characteristics, and force mechanism were studied.The study results show that the core area of the joint with a plug-in connection scheme can effectively transfer the vertical load.The top surface of the core area is subjected to local pressure, and the diffusion region of the local pressure can extend to the supporting column.The lateral confinement effect of the core concrete in the intersection zone is significant to benefit the deformation and bearing capacity of this zone.The inserted depth of the inclined columns is the critical parameter affecting the mechanical properties.With the increased inserted depth, the bearing capacity of the joint represents a 18% growth in maximum, and the position where the steel tubes first reach the yield strain and where the local buckling first occurs can be changed.The stiffness and bearing capacity of the intersection zone can be increased by setting stiffening ribs.Then the failure position is shifted to other areas.The formulae for calculating the bearing capacity of Y-shaped transfer joints with double square inclined columns and a circular supporting column under symmetrical vertical load were proposed based on the mechanical characteristics of the joints obtained from the tests.The average ratio of the calculated results to the test results is 0.879

关 键 词：钢管混凝土柱 Y形节点 竖向荷载 静力试验 破坏模式 承载力计算 

分 类 号：TU398[建筑科学—结构工程] TU317.1