摘要
为研究异形柱结构火灾后偏压性能,对7根L形钢管混凝土叠合短柱进行偏压试验,并按等强度原则将钢管替换成等强钢筋,设计4根L形等强钢筋混凝土短柱进行对比,研究受火时间、偏心率、内部构造对L形柱火灾后受力性能的影响。通过有限元分析软件ABAQUS建立有限元模型,在验证模型可靠性基础上对受火后不同偏心率、不同钢管强度、不同核心混凝土强度的构件进行承载力分析,提出火灾后L形钢管混凝土叠合短柱单向偏压承载力计算公式。结果表明:构件外部钢筋混凝土具有良好的隔火、绝热作用,受火120 min后钢管内部混凝土经历最高温度为240℃;构件火灾后承载力随受火时间增加而降低,L形等强钢筋短柱受火120 min后承载力较常温试件降低32%;L形钢管混凝土叠合短柱能有效降低试件火灾后承载力下降幅度,相同受火时间下钢筋构件下降幅度是钢管构件的1.4~3.3倍;有限元参数分析表明相较于其他参数受火时间、偏心率对构件承载力影响更加显著;简化公式的计算结果与试验结果、模拟结果吻合较好,误差在10%以内,能为火灾后钢管混凝土叠合柱损伤评估、修复加固提供参考。
In order to study the eccentric compression performance of special-shaped column structure after fire,seven L-shaped concrete-filled steel tube composite short columns were subjected to eccentric compression test.According to the principle of equal strength,the steel tube was replaced with equal strength steel bar,and four Lshaped equal strength reinforced concrete short columns were designed for comparison.The effects of fire time,eccentricity and internal structure on the mechanical properties of L-shaped columns after fire were studied.The finite element model was established by finite element analysis software ABAQUS.On the basis of verifying the reliability of the model,the bearing capacity of members with different eccentricity,different steel tube strength and different core concrete strength after fire was analyzed,and the calculation formula of unidirectional eccentric compression bearing capacity of L-shaped concrete-filled steel tube composite short column after fire was proposed.The results show that the reinforced concrete outside the member has good fire insulation and adiabatic effect.After 120 minutes of fire,the maximum temperature of the concrete inside the steel pipe is 240℃.The bearing capacity of the component after fire decreases with the increase of fire time.The bearing capacity of the L-shaped reinforced short column after 120 minutes of fire is 32%lower than that of the normal temperature specimen.The L-shaped concrete-filled steel tube composite short column can effectively reduce the decrease of the bearing capacity of the specimen after fire,and the decrease of the reinforcement member is 1.4~3.3 times that of the steel tube member under the same fire time.The finite element parameter analysis shows that the influence of the fire time and eccentricity on the bearing capacity of the component is more significant than that of other parameters.The calculation results of the simplified formula are in good agreement with the experimental results and simulation results,and the error is within 10%,which can provide reference for damage assessment,repair and reinforcement of concrete-filled steel tubular composite columns after fire.
作者
陈海彬
刘伟浩
张皓铭
赵寅鹏
周中一
CHEN Haibin;LIU Weihao;ZHANG Haoming;ZHAO Yinpeng;ZHOU Zhongyi(College of Civil and Architectural Engineering,North China University of Science and Technology,Tangshan 063210,China;Hebei Key Laboratory of Earthquake Engineering and Disaster Prevention,North China University of Science and Technology,Tangshan 063210;Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China)
出处
《建筑结构学报》
CSCD
北大核心
2024年第S2期147-158,共12页
Journal of Building Structures
基金
国家重点研发计划(2022YFF0608904)
国家自然科学基金项目(51478162,51608196)
唐山市科技局应用基础研究项目(23130213E)
关键词
火灾后
钢管混凝土
偏压性能
数值模拟
静力试验
after fire
concrete filled steel tube
eccentric compression performance
numerical simulation
static test
