不同约束形式的薄壁钢管混凝土柱轴心受压试验及承载力计算  

Axial Compression Experiment and Bearing Capacity Calculation of Thin-walled Concrete Filled-steel Tube Columns with Different Restraint Forms

作　　者：王振山[1,2] 冯永建 卢俊龙[2] 李晓蕾[2] 田建勃[2] WANG Zhenshan;FENG Yongjian;LU Junlong;LI Xiaolei;TIAN Jianbo(State Key Lab.of Eco-hydraulics in Northwest Arid Region of China,Xi’an Univ.of Technol.,Xi’an 710048,China;School of Civil Eng.and Architecture,Xi’an Univ.of Technol.,Xi’an 710048,China)

机构地区：[1]西安理工大学西北旱区生态水利国家重点实验室,陕西西安710048 [2]西安理工大学土木建筑工程学院,陕西西安710048

出　　处：《工程科学与技术》2021年第1期18-28,共11页Advanced Engineering Sciences

基　　金：国家自然科学基金项目(51778527);陕西省自然科学基金项目(2020JQ-628)。

摘　　要：为了提高薄壁钢管混凝土柱的局部抗屈曲性能,改善变形能力较差的问题,提出一种约束形式螺旋加劲肋。通过对普通钢管、直肋、开孔直肋、内螺旋肋、外螺旋肋、外螺旋肋-钢筋等6种不同形式的薄壁钢管混凝土组合柱进行了轴心受压试验研究,对比分析了破坏过程、极限荷载、位移及应变等,得到了螺旋加劲型薄壁钢管混凝土柱的破坏模式及机理。研究结果表明:设置直肋、开孔直肋、螺旋肋均能提高试件的受力性能,但三者的约束机制差异较大。竖向加劲肋对提高承载力作用显著;螺旋肋主要通过约束钢管横向变形而发挥作用,其竖向刚度贡献较小。针对螺旋肋外置形式,由于外部混凝土变形缺少限制,导致其开裂严重,提前退出工作;当设置竖向钢筋后;钢筋与螺旋肋对混凝土形成“块状”约束,大大延缓了裂缝发展,可与核心构件较好协同工作,承载力与变形能力显著提升。提出的螺旋加劲肋可较好解决传统薄壁钢管混凝土变形能力差的问题,当螺旋肋外置后,可利用外部混凝土对钢管进行保护,免除防火与防腐处理,大大降低后期维护成本;该新型组合构件受力性能良好,可为其工程应用提供技术支持。In order to improve the local buckling resistance of thin-walled concrete filled-steel tube column,a type of restraint namely spiral stiffener was proposed.Through the axial compression experiments of the six kinds of the concrete filled-steel tube composite columns,i.e.,the common steel pipe,straight rib,built-in opening straight rib,inner spiral rib,spiral rib and external spiral rib-reinforced,the failure process,ultimate load,displacement and strain were compared and analyzed,and the failure mode and mechanism of the spiral stiffened thin-walled concretefilled steel tube column were obtained.The results show that,the bearing capacity of the thin-walled concrete-filled steel tubular can be effectively improved by setting straight rib,opening straight rib and internal spiral rib.However,their constraint mechanisms were quite different.The vertical stiffener played a significant role in improving the bearing capacity,while the spiral rib played a major role by restraining the transverse deformation of the steel tube,and its contribution to the vertical stiffness was small.For the spiral rib external form,due to the lack of restrictions on the external concrete deformation,the cracking of spiral rib was serious and the spiral rib quitted service in advance.When the vertical steel bar was set,the steel bar and spiral rib formed“block”constraints on the concrete,which delayed the development of cracks,worked well with the core members,and improved the bearing capacity and deformation capacity.The spiral stiffener proposed in this paper can better solve the problem of poor deformation capacity of traditional thin-walled concrete filled steel tube.When the spiral rib was placed outside,the steel pipe can be protected by external concrete,avoiding fire prevention and anticorrosion treatment,thus reducing the maintenance cost in the later stage.The new composite members have good mechanical performance,and the research work can provide technical support for the engineering application.

关 键 词：薄壁钢管混凝土 螺旋加劲肋 轴压试验 破坏模式 极限承载力 

分 类 号：TU528.572[建筑科学—建筑技术科学]