摘要
为研究钢箱梁与钢-UHPC组合梁之间钢混结合段的力学性能,该文以主跨1 160 m的观音寺长江大桥为背景,通过精细化有限元建模,分析了钢混结合段在最不利荷载工况下的受力特点,揭示了钢混结合段的传力机理,并讨论了影响结合段受力的主要因素。结果表明:在最不利荷载工况下,钢混结合段各构件的应力均在160.4 MPa以内,低于材料强度设计值,具有充足的安全储备;在纵桥向,结合段对钢箱梁底板及中腹板的传力影响较小,应力从钢箱梁到组合梁方向总体呈下降趋势,变化幅度在20 MPa以内;钢格室顶板、腹板、底板应力水平在承压板附近分别下降了25.6%、73.3%、3.50%;剪力钉传力过程中,钢格室顶板剪力钉传力占比最多,且越靠近组合梁端比例越高,最高达到57%;增加结合段填充混凝土厚度可降低结构应力,取350~400 mm厚度能实现结构的最优受力;结合段越长,越有利于剪力钉的应力过渡。
To study the mechanical properties of the steel-concrete composite section between steel box girders and steel-ultra-high performance concrete(UHPC)composite girders,the Guanyinsi Yangtze River Bridge with a main span of 1160 m was used as the background.Through refined finite element modeling,the stress characteristics under the most unfavorable load conditions and transmission mechanism of the steel-concrete composite section were analyzed,and the main factors affecting the stress of the composite section were discussed.The results indicate that under the most unfavorable load conditions,the stress of each component in the steel-concrete composite section is within 160.4 MPa,which is lower than the material strength design value,and there is sufficient safety reserve.Along the longitudinal direction of the bridge,the influence of the composite section on the force transmission of the bottom plate and middle web of the steel box girder is relatively small,and the stress generally shows a downward trend from the steel box girder to the composite girder direction,with a variation amplitude within 20 MPa.The stress levels of the top plate,web plate,and bottom plate of the steel lattice chamber decrease by 25.6%,73.3%,and 35%near the bearing plate,respectively.In the process of transmission force through shear nails,the proportion of force transmitted by shear nails of the top plate in the steel lattice chamber is the highest,and a closer proximity to the end of the composite girder indicates a higher proportion,with a maximum of 57%.Increasing the thickness of concrete filled in the composite section can reduce the structural stress,and a thickness of 350 mm-400 mm can achieve the optimal stress of the structure.A longer composite section is more conducive to the stiffness transition of the shear nails.
作者
李秋
职海涛
彭彦庆
彭建新
袁勤
吴学伟
LI Qiu;ZHI Haitao;PENG Yanqing;PENG Jianxin;YUAN Qin;WU Xuewei(Bridge Design Institute,CCCC Second Highway Consultants Co.,Ltd.,Wuhan,Hubei 430000,China;School of Civil and Environmental Engineering,Changsha University of Science&Technology,Changsha,Hunan 410114,China;Hubei Communications Investment Co.,Ltd.,Wuhan,Hubei 430000,China)
出处
《中外公路》
2025年第6期119-126,共8页
Journal of China & Foreign Highway
基金
国家重点研发计划项目(编号:2021YFB2600900)
国家自然科学基金资助项目(编号:52078056,52378125)。
关键词
组合梁斜拉桥
钢混结合段
有限元模拟
传力机理
参数分析
cable-stayed bridge with composite girder
steel-concrete composite section
finite element simulation
force transmission mechanism
parameter analysis
