变截面圆钢管混凝土短柱轴心受压性能研究  

Axial compression performance of CFST short columns with variable circular cross sections

作　　者：龙刚[1,2] 刘永健 朱伟庆[1] 任鹏举[1,3] LONG Gang;LIU Yongjian;ZHU Weiqing;REN Pengju(School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China;Xi'an Huantong Municipal Engineering Project Management Co.,Ltd.,Xi'an 710038,Shaanxi,China;Key Laboratory of Road and Traffic Engineering of Ministry of Education,Tongji University,Shanghai 200092,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]西安环通市政工程项目管理有限公司,陕西西安710038 [3]同济大学道路与交通工程教育部重点实验室,上海200092

出　　处：《建筑科学与工程学报》2023年第6期45-57,共13页Journal of Architecture and Civil Engineering

基　　金：国家自然科学基金项目(51978061,51508027);陕西省高校科协青年人才托举计划项目(20180409)。

摘　　要：为研究变截面圆钢管混凝土短柱的轴压性能,开展6个变截面和2个等截面圆钢管混凝土短柱的轴压试验,试验参数包括变角度和套箍指标。从短柱整体轴压性能(破坏形态、荷载-位移曲线和变形能力)和截面轴压性能(钢管应变)两个层面对比分析变截面与等截面圆钢管混凝土短柱的异同,并得到各设计参数对整体和截面轴压性能的影响。在此基础上,建立了变截面圆钢管混凝土的截面轴压承载力计算方法,并通过对比所提计算方法和规范计算公式计算得到的轴压承载力与试验实测值,验证了计算方法的准确性。结果表明:试件上部截面的钢管纵向应变和环向应变发展较下部截面更快,弹塑性阶段和下降阶段试件整体的受力性能更多取决于试件的顶部区域和顶截面;相比于等截面短柱,在相同荷载作用下变截面圆钢管混凝土短柱中间截面的钢管纵向和环向应变更大;变截面圆钢管混凝土的钢-混相互作用非常明显;提出的计算方法不仅能考虑圆钢管与混凝土的相互作用,而且能合理考虑钢-混相互作用随变角度的增大而逐渐增强这一特性,计算得到的轴压承载力与试验值吻合较好;与其他规范相比,GB 50936—2014和CECS 28:2012中公式的计算结果更加准确,考虑到其简单实用,也可用来偏于安全地计算变截面钢管混凝土构件的截面轴压承载力。In order to study the axial compression performance of concrete filled steel tube(CFST)short columns with variable circular cross sections,six CFST short columns with variable circular cross sections and two CFST short columns with constant circular cross sections were tested under axial compression.The test parameters included variable angle and hoop index.Comparative analysis of the similarities and differences between CFST short columns with variable circular cross section and constant circular cross section was carried out from two aspects:the overall axial compression performance of the short column(failure mode,load-displacement curve,and deformation capacity)and the axial compression performance of the section(steel tube strain).The influence of various design parameters on the overall and cross section axial compression performance was obtained.On the basis,a calculation method for the axial compressive bearing capacity of CFST with with variable circular cross section was established.The accuracy of the proposed calculation method was verified by comparing the axial compression bearing capacity values calculated by the proposed calculation method and the standard calculation formula with the experimental measured values.The results show that the longitudinal and circumferential strains of the steel tube in the upper section of the specimen develop faster than those in the lower section.The overall stress performance of the specimen during the elastic-plastic and descending stages depends more on the top area and top section of the specimen.Compared to constant cross-section short columns,the longitudinal and circumferential stresses of the steel tube in the middle section of CFST short columns with variable circular cross sections is larger under the same load.The steel-concrete interaction of CFST with variable circular cross section is very obvious.The proposed calculation method can not only consider the interaction between circular steel tube and concrete,but also reasonably consider the characterist

关 键 词：桥梁工程 钢管混凝土短柱 试验研究 轴压性能 变截面 承载力 

分 类 号：U448.36[建筑科学—桥梁与隧道工程]