摘要
为分析环向钢管对核心混凝土受压承载性能的提高效果,对15个矩形开槽钢管混凝土柱进行轴压试验,研究倒角半径和钢管厚度对其受压性能的影响.基于圆形箍筋约束混凝土的极限应力计算模型,引入考虑截面形状的承载力折减系数,提出了矩形开槽钢管混凝土柱极限应力计算模型.结果表明,矩形开槽钢管约束混凝土柱的受压性能与钢管厚度及倒角半径密切相关,且钢管的开槽构造能够有效地避免钢管的纵向屈服.倒角半径越小,钢管约束效果越差,应力-应变曲线在屈服后会出现下降段,且钢管厚度越小,峰值后荷载下降越快.倒角半径越大,约束效率越高,应力-应变曲线在屈服后较平缓或出现上升段,但钢管厚度较大时,其环向约束效果下降,极限应力提高幅度也明显下降.
To analyze the improvement effects of hoop steel tubes on the compressive behaviors of core concrete, axial compression tests were carried out on fifteen rectangular concrete-filled slotted steel tubular columns. The effects of the chamfer radius and the thickness of the steel tube on the compressive behaviors of the rectangular concrete-filled slotted steel tubular columns were studied. Based on the calculation model of the ultimate stress of concrete confined by circular stirrups, the calculation model of the ultimate stress for rectangular concrete-filled slotted steel tubular columns was proposed by introducing the reduction coefficient of bearing capacity considering the section shape. The results show that the compressive behaviors of the rectangular concrete-filled slotted steel tubular columns are closely related to the thickness of the steel tube and the chamfer radius, and the slotted structure of the steel tube can avoid the longitudinal buckling of the steel tube. A smaller chamfer radius can induce worse confinement effects of the steel tube, accompanied by the appearance of a descending segment of the stress-strain curve after yielding. And with the decrease of the thickness of the steel tube, the load decreases with a faster speed after the peak stress. Besides, a higher confinement efficiency can be obtained with a larger chamfer radius, accompanied by the appearance of a horizontal or ascending segment of the stress-strain curve after yielding. But the effects of lateral confinement decreases when the thickness of steel tube is large, and the improvement of the ultimate stress also decreases obviously.
作者
魏洋
柏佳文
张依睿
丁明珉
李国芬
Wei Yang;Bai Jiawen;Zhang Yirui;Ding Mingmin;Li Guofen(School of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China)
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第2期237-243,共7页
Journal of Southeast University：Natural Science Edition
基金
国家自然科学基金资助项目(51778300)
江苏省自然科学基金资助项目(BK20191390)
江苏省“六大人才高峰”资助项目(JZ-017)
江苏省“333工程”资助项目(BRA2016421)
江苏省“青蓝工程”资助项目.
关键词
钢管混凝土
开槽
倒角半径
轴压性能
约束效率
concrete filled steel tube
slotting
chamfer radius
axial compressive behavior
confinement efficiency
作者简介
魏洋(1978-),男,博士,教授,博士生导师,wy78@njfu.edu.cn。
