摘要
为研究波形钢腹板PC组合箱梁抗火性能及抗火设计方法,采用ANSYS软件建立热-力耦合分析模型,分析了受火工况下组合箱梁的挠度、侧向位移、钢束张力以及抗弯承载能力的变化规律,并以组合箱梁的挠度和腹板侧向位移为判定指标,提出了一种关于波形钢腹板组合箱梁的抗火设计方法。结果表明:荷载比是影响组合箱梁挠度发展的关键因素;受火全过程中,钢束张力的变化对组合箱梁挠度、侧向位移以及承载能力的变化影响较大;组合箱梁受火初期挠度增长缓慢,在横隔板处形成塑性铰后,跨中挠度快速增大,然后在加载处形成塑性铰,随即组合箱梁因顶板被压碎而破坏;采用抗力准则判断组合箱梁的耐火极限偏于不安全;通过在组合箱梁的波形钢腹板转角处增设立柱,能够减缓组合箱梁挠度和腹板侧向位移的发展,有效提高该类组合箱梁的抗火性能,当无立柱组合箱梁达到耐火极限时,有立柱组合箱梁跨中挠度为无立柱组合箱梁跨中临界挠度的64.3%。研究成果可为该类型组合箱梁的抗火设计提供参考。
To study the fire resistance and design method of PC composite box girder with corrugated steel webs(CSWs),ANSYS software was used to establish a thermal-mechanical coupling analysis model.The variation laws of deflection,horizontal displacement,tendon tension and flexural bearing capacity of composite box girder under fire conditions were analyzed.The deflection and horizontal displacement of composite box girder was considered as the judgment indexes,and fire resistance design method of composite box girder with CSWs was proposed.The results show that the load ratio is a key factor affecting the deflection of composite box girder.The change of tendon tension has a large influence on the deflection,lateral displacement and bearing capacity of composite box girder.The deflection of composite box girder increases slowly at the initial stage of fire.After the plastic hinge is formed at the diaphragm,the mid-span deflection increases rapidly,and then the plastic hinge is formed at the loading position,and then the composite box girder fails due to the crush of the top plate.Using the resistance criterion to judge the fire resistance limit of composite box girder is unsafe.By adding columns at the corner of corrugated steel webs of composite box girders,the deflection of composite box girders and the lateral displacement of webs can be reduced,and the fire resistance of composite box girders can be effectively improved.When the composite box girder without columns reaches the fire resistance limit,the mid-span deflection of the composite box girder with columns is 64.3%of the mid-span critical deflection of the composite box girder without columns.The research results can provide a reference for fire resistancedesign of this type of compositebox girder.
作者
沈强
郑尚敏
程海根
沈磊
唐维胜
魏岑茜
SHEN Qiang;ZHENG Shangmin;CHENG Haigen;SHEN Lei;TANG Weisheng;WEI Cenxi(School of Civil Engineer and Architecture,East China Jiaotong University,Nanchang 330013,China;State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure,East China Jiaotong University,Nanchang 330013,China;College of Civil Engineering,Tongji University,Shanghai 200092,China)
出处
《建筑钢结构进展》
CSCD
北大核心
2023年第10期46-53,共8页
Progress in Steel Building Structures
基金
国家自然科学基金(52068025、51968024)
江西省研究生创新专项资金(YC2021-S438)。
关键词
抗火性能
抗火设计
温度场
波形钢腹板组合箱梁
fire resistance
fire resistant design
temperature field
composite box girder with corrugated steel webs
