基于“统一理论”的异形截面多腔钢管混凝土柱轴压承载力计算  

AXIAL COMPRESSIVE STRENGTH CALCULATION BASED ON THE ‘UNIFIED THEORY’ FOR SPECIAL-SHAPED CFT COLUMNS WITH MULTIPLE CAVITIES

作　　者：武海鹏 曹万林[1] 董宏英[1] WU Hai-peng;CAO Wan-lin;DONG Hong-ying(Key Laboratory of Urban Security and Disaster Engineering of China Ministry of Education,Beijing University of Technology,Beijing 100124,China;Postdoctoral Research Station of Mechanics,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124 [2]北京工业大学力学博士后流动站,北京100124

出　　处：《工程力学》2019年第8期114-121,共8页Engineering Mechanics

基　　金：国家自然科学基金青年科学基金项目(51808014);北京市博士后工作经费资助项目(2017-ZZ-055)

摘　　要：基于钢管混凝土“统一理论”成果及部分试验结果,研究钢管混凝土柱截面形状由三角形、正方形……正n边形到圆形变化时,钢管对混凝土约束效应的变化规律。通过划分混凝土有效与非有效约束区,引入形状效率的概念,对约束效应进行折减,采用统一的圆形截面计算公式进行计算,回归分析得到截面几何形状内角角度与混凝土约束区划分的关系;然后,以四边形截面为例,研究截面图形规则性与约束效应的关系,给出计算方法;最后,将异形截面多腔钢管混凝土截面按照腔体拆分为简单多边形截面,引入形状效率和规则性的影响,分别进行轴压承载力计算,叠加各腔体承载力后得到整个截面的轴压承载力。研究结果表明:正多边形截面钢管混凝土有效与非有效约束区边界二次曲线初始切线角度与正多边形内角呈线性关系;提出的基于“统一理论”的不规则异形截面多腔钢管混凝土柱轴压承载力计算方法可较好的反应其约束特征,计算结果与实测结果符合较好,满足工程设计要求。Based on the unified theory for concrete filled steel tubes(CFT)and the test results,the variation of the concrete confinement effect when the cross-sectional shapes change from triangle,square,regular polygon to circular is investigated.The concrete is divided into effective and ineffective confined regions.A cross-sectional efficiency coefficient is introduced to discount the confinement effect.The unified circular cross-sectional formula is applied to calculate the axial compressive strength.By regression analysis,the relationship between the cross-sectional interior angle and the confinement effect is found.Taking quadrangle sections for example,the relationship between the regularity and the confinement effect is investigated,and a calculation method is provided.By splitting a special-shaped cross-section with multiple cavities into separate polygons and considering the influence of the shape efficiency and regularity,the strength of each cavity CFT is calculated and summated to obtain the total axial compressive strength.The results show that in regular polygon steel tube confined concrete,a liner relationship is exhibited between the interior angle and the initial tangent line angle of the second-order curved boundary between the effective and ineffective confined concrete regions.The proposed axial compressive strength calculation method for special-shaped CFT columns with multiple cavities can well reflect the real confinement features.The calculation results match the test results well and the method can fulfil the engineering design requirements.

关 键 词：结构工程 钢管混凝土 轴压承载力 统一理论 异形截面 

分 类 号：TU398.9[建筑科学—结构工程]