圆形Q690高强钢管混凝土轴压短柱试验研究  

Experimental Investigation of Axial Compression Behaviour of Stub Circular Concrete-Filled Steel Tubes with Q690 High-Strength Steel

作　　者：门朋飞 何浩祥 钟国辉[1,2] Pengfei Men;Ho-Cheung Ho;Kwok-Fai Chung(Department of Civil and Environmental Engineering,The Hong Kong Polytechnic University,Hong Kong 999077,China;Chinese National Engineering Research Centre for Steel Construction(Hong Kong Branch),The Hong Kong Polytechnic University,Hong Kong 999077,China)

机构地区：[1]香港理工大学土木与环境工程学院,中国香港999077 [2]香港理工大学国家钢结构工程技术研究中心香港分中心,中国香港999077

出　　处：《钢结构（中英文）》2024年第5期41-48,共8页Steel Construction（Chinese & English）

基　　金：国家钢结构工程技术研究中心香港分中心项目(1-BBY3,BBT1);香港理工大学项目(BD6F)。

摘　　要：圆形钢管混凝土可以充分发挥钢管和混凝土的组合作用,使得钢管混凝土承载力和延性得到明显提升,因而广泛应用于工程结构中。将高强钢应用于钢管混凝土柱,可以减小构件尺寸和自重,使结构在节省材料用量的同时获得更大的可用空间,更加经济环保。然而,现行钢管混凝土设计规范主要是依据普通钢材强度等级的研究成果制定的,对采用高强钢的钢管混凝土的适用性尚未可知。此外,针对高强钢管混凝土短柱轴压性能,现有研究主要关注其在承载时的结构性能,而很少关注钢管和内填混凝土在不同变形阶段分别承担轴力的贡献。因此,基于试验对高强钢管混凝土短柱的轴压性能展开了研究。首先,对6个短柱进行了轴压试验,包括3个钢管混凝土试件和3个纯钢管试件。主要的试验参数为钢材强度等级,包括Q355,Q460和Q690。之后,基于试验结果,分析了试件的破坏形态、荷载-位移曲线、承载力以及钢管和内填混凝土的轴力贡献。最后,探讨了现行设计规范对圆形钢管混凝土轴压短柱承载力的适用性。试验结果表明:所有纯钢管和钢管混凝土试件均表现出了良好的延性;由于混凝土的存在,钢管混凝土的承载力比纯钢管的承载力提高了30%以上。基于纯钢管和钢管混凝土的应变分析结果,分离了钢管混凝土钢管和内填混凝土的轴力贡献。结果表明:钢管提供的约束作用使得混凝土所承担的轴力明显增加,且钢材强度等级越高,混凝土轴力提高效果越明显;尽管钢管提供了横向约束作用,但其轴力贡献与其屈服承载力相比未明显折减。试验结果和规范预测结果的对比分析表明:现行中国规范GB 50936—2014《钢管混凝土结构技术规范》可以有效预测采用普通强度钢材的钢管混凝土试件的承载力,但当钢管采用高强度钢材时,规范将给出过于保守或偏于危险的预测结果;现行欧Circular concrete-filled steel tubes(CFSTs)can fully utilize the composite action of the steel tube and infilled-concrete,and thus its load-bearing capacity and ductility can be significantly enhanced.Therefore,they are widely used in engineering structures.The application of high-strength steel(HSS)in CFST columns can reduce the size and self-weight of the members and allows structures to achieve greater usable space while saves material,which is more economical and environmentally friendly.However,the current design codes for CFSTs are primarily based on research achievements using ordinary steel strength grades,and whether the codes are still applicable to CFSTs with high-strength steel remains unknown.In addition,existing research on the axial compression behaviour of CFST stub columns with HSS mainly focuses on the structural behaviour at the ultimate load,while little attention is given to the axial force contributions of the steel tube and the infilled concrete at different deformation stages.Therefore,this paper experimentally investigated the axial compression behaviour of CFST stub columns with HSS.Firstly,axial compression tests were conducted on six stub columns,including three CFST columns and three pure steel tubes.The main test parameter was the steel grade,including Q355,Q460,and Q690.Subsequently,based on the test results,the failure states,load-deflections,load-bearing capacity,and axial force contributions of the steel tube and infilled concrete were analysed.Finally,the applicability of the current design codes in predicting the load-bearing capacity of circular stub CFST columns under compression was discussed.The test results indicate that all the pure steel tube and CFST specimens exhibited good ductility.Due to the presence of concrete,the load-bearing capacities of CFST columns were increased by more than 30%compared to these of pure steel tubes.Based on the strain gauges attached on the surface of the steel tube,the axial resistance contributions of the steel tube and infilled concrete o

关 键 词：钢管混凝土短柱 圆形截面 Q690高强钢 轴压承载力 轴力贡献 试验研究 

分 类 号：TU398.9[建筑科学—结构工程]