外套钢管夹层混凝土加固RC短柱轴压承载力统一计算方法研究  

Unified calculation model of axial compressive capacity of steel tube and sandwiched concrete jacketed RC stub columns

作　　者：卢亦焱[1] 赵晓博 李杉[1] 李伟捷[1] LU Yiyan;ZHAO Xiaobo;LI Shan;LI Weijie(School of Civil Engineering,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学土木建筑工程学院,湖北武汉430072

出　　处：《建筑结构学报》2022年第12期70-81,共12页Journal of Building Structures

基　　金：国家自然科学基金项目(52238006);湖北省技术创新专项重大项目(2019ACA142)。

摘　　要：外套钢管夹层混凝土加固法利用了钢管混凝土组合结构的优良受力特性,具有材料利用率高、截面增加少和施工简便等优点,然而,目前针对组合加固柱承载力计算方面的研究成果不具有统一性和广泛的适应性,制约了该加固技术的推广应用。为此,提出外套钢管夹层混凝土加固RC短柱轴压承载力统一计算方法。该方法首先考虑混凝土约束作用的差别及钢管屈曲特性的不同,将各种截面形式组合加固柱转化为外圆内圆的截面形式。然后从截面受力平衡、材料本构方程及不同材料之间的变形协调出发,推导出具有统一表达式的外套钢管夹层混凝土加固RC短柱轴压承载力计算方法。对已有的研究成果中共计81个不同截面形式组合加固轴压短柱承载力进行计算并与试验结果对比,计算结果与试验结果比值的平均值为0.947,标准差和变异系数分别为0.077和0.081,表明采用提出的计算模型可精确且偏于安全地计算外套钢管夹层混凝土加固RC短柱的轴压承载力。The method of strengthening RC columns with steel tube and sandwiched concrete jackets takes advantage of the excellent mechanical characteristics of concrete-filled steel tubes,and has the advantages of high material utilization rate,minimal increase in section dimensions and easy for construction.However,there is no widely recognized or applicable calculation methods for the load capacity of the strengthened columns,which restricts the applications of this strengthening technology.Therefore,a unified model for calculating the axial load capacity of the strengthened RC columns were proposed.Firstly,considering the difference in the confinement effect on the concrete and the buckling characteristics of the steel tube,the different sectional forms of composite columns were transformed into equivalent circular sections for both inner and outer parts.Then,a unified model for calculating the load capacity of the strengthened columns was derived using the section force equilibrium equation,material constitutive relationship and circumferential deformation compatibility condition.The load capacities of 81 specimens with different section forms under axial loading were calculated and compared with the experimental results.The average value of the ratios between the calculated and the tested results is 0.947,and the standard deviation and the coefficient of variation are 0.077 and 0.081,respectively,exhibiting the accuracy as well as the safety of the unified model.

关 键 词：RC短柱 外套钢管夹层混凝土 加固 统一计算模型 轴心受压承载力 

分 类 号：TU375.3[建筑科学—结构工程] TU312.1