摘要
为研究混凝土徐变对桥梁结构成桥预拱度的影响,以国内高速铁路无砟轨道桥梁同类型结构跨度最大、桥墩最高的陕西省铜川市王家河特大桥为工程背景,采用Midas civil软件建立全桥有限元模型,使用正交设计法研究预应力、混凝土自重等参数对徐变变形和应力的敏感性程度,然后使用未知荷载系数法优化成桥吊杆力,并研究优化方案对后期徐变的影响规律,最后将考虑结构后期徐变的成桥预拱度与规范计算值进行对比分析。分析结果表明:当多参数共同作用时,预应力和混凝土自重对徐变变形影响显著;延长存梁时间和加载龄期使后期徐变变形小且慢,更有利于控制轨道平顺性;吊杆力优化能明显减小主梁和主拱的弯矩及变形,后期徐变也明显减小;考虑徐变作用时预拱度幅值明显减小,且使桥梁结构的线形更平顺。
In order to study the influence of concrete creep deformation on the pre-camber of the bridge structure,the Wangjiahe Bridge in Tongchuan City,Shaanxi Province,which has the largest structural span and the highest pier of the same type of high-speed railway ballastless track bridge in China,the finite element model of the full bridge was established by Midas civil software.The sensitivity of parameters of prestress and concrete self-weight on creep deformation and stress were studied by orthogonal design method.Then,the bridge suspender force was optimized by the unknown load coefficient method.The influence of the optimization plan on the later creep deformation was studied.Finally,the pre-camber of the completed bridge considering the late creep and the standard calculation value were compared and analyzed.The analysis results show that when multiple parameters work together,prestress and concrete self weight have a significant impact on creep deformation;That extending the beam storage time and loading age make the later creep deformation small and slow,which is more conducive to controlling the track smoothness;The optimized boom force can significantly reduce the bending moment and deformation of the main beam and main arch,and the late-creep is also significantly reduced;Considering the creep effect,the pre-camber amplitude significantly reduces,and the linear shape of the bridge structure is smoother.
作者
李贺明
穆鹏
李子奇
张蕾
Li Heming;Mu Peng;Li Ziqi;Zhang Lei(Civil Engineering College,Lanzhou Jiaotong University,Lanzhou 730070,China;Xicheng Railway Passenger Dedicated Line Shaanxi Co.,Ltd.,Xi’an 710000,China;China Railway First Survey and Design Institute Group Co.,Ltd.,Xi’an 710043,China)
出处
《市政技术》
2024年第6期99-104,共6页
Journal of Municipal Technology
基金
甘肃省自然科学基金资助项目(20JR10RA237)
甘肃省高等学校青年博士基金项目(2023QB-045)。
关键词
高速铁路桥梁
无砟轨道
徐变变形
参数敏感性
吊杆力优化
成桥预拱度
high-speed railway bridge
ballastless tracks
creep deformation
parameter sensitivity
the suspender force optimization
pre-camber of the completed bridge
