摘要
为了解提篮式拱梁组合体系桥梁拱梁结合段的受力特性,以福州至长乐机场城际铁路乌龙江大桥为背景,建立该桥拱梁结合段精细化有限元模型,考虑几何大变形、材料非线性等效应进行全过程非线性分析,得到不同荷载阶段下拱梁结合段的应力分布,研究拱梁结合段的破坏模式和受力特性。结果表明:随着荷载增加,中拱拱脚外侧加劲肋与底板交界处最先屈服,最不利截面位于拱肋壁板与拱脚横隔板交界处;拱梁结合段的弹性承载力系数为2.32,塑性承载力系数为4.71。当荷载达3.57倍最不利荷载组合时,最不利截面拱肋壁板与拱脚横隔板相交的角点先达到屈服;当荷载达4.25倍最不利荷载组合时,1/2最不利截面屈服,屈服区域由角点屈服向拱肋上部区域扩展;当荷载达4.71倍最不利荷载组合时,最不利截面大部分屈服,拱肋壁板屈服区域向整个截面扩展,拱肋因屈服区域过大而丧失承载力。拱肋壁板屈服区域扩展过程中,内、外侧加劲肋逐步屈服;设置外侧加劲肋有利于推迟拱肋壁板的屈服。
This study investigates the mechanical property of the knuckles of the arch bridge of combined basket-handle arch and continuous deck system,with the Wulongjiang River Bridge carrying a portion of the Fuzhou Metro Binhai Express as a case.A high-fidelity finite element model of the knuckle was established for whole-process nonlinear analysis,considering the effects of large deformation and material nonlinearity,to obtain the stress distributions in the knuckle at different load stages and to analyze the failure modes and mechanical property of the knuckle.It is shown that as the loads increase,the intersections of the outer stiffeners and bottom plates of the arch springings of the central arch were the first to yield,with the most unfavorable cross-section located at the intersection of the arch walls and diaphragm inside the arch springing.The elasticity and plasticity coefficients of the knuckle were 2.32 and 4.71,respectively.When the loads reached 3.57 times of the most unfavorable load combination,the corner of the intersection of the arch walls and diaphragm inside the arch springings in the most unfavorable cross-section yielded first.When the loads reached 4.71 times of the most unfavorable load combination,a large portion of the most unfavorable cross-section yielded,and the yielded zones in the arch walls spread towards the whole cross-section,as a result,the arch lost load bearing capacity due to the oversized yielding zone.During the spread of the yielding zone of the arch walls,the inner and outer stiffeners yielded one after another.It is concluded that adding external stiffeners can delay the yield of the arch walls.
作者
熊安书
肖锋
陈亮
蔡威
赵秋
XIONG Anshu;XIAO Feng;CHEN Liang;CAI Wei;ZHAO Qiu(Guangzhou Metro Design&Research Institute Co.,Ltd.,Guangzhou 510010,China;School of Civil Engineering,Fuzhou University,Fuzhou 350108,China)
出处
《世界桥梁》
北大核心
2024年第4期99-105,共7页
World Bridges
基金
国家重点研发计划项目(2017YFB1201204)。
关键词
提篮式钢箱拱
拱梁组合体系
拱梁结合段
应力分布
受力特性
有限元法
basket-handle steel box arch
combined arch and girder system
arch-deck knuckle
stress distribution
mechanical property
finite element method
