摘要
针对大跨度自锚式悬索桥跨越通航流域时不能采用常规支架法施工主跨钢箱梁的问题,提出了"先斜拉,后悬索"无支架法的总体施工方案,即先形成临时斜拉桥,再进行斜拉桥向悬索桥的体系转换。以600 m超大跨度的鹅公岩自锚式悬索桥为分析案例,采用无应力状态控制法实现了两种独立缆索支撑体系——临时斜拉桥和自锚式悬索桥共存。通过体系转换方案比选出推荐方案,表明临时斜拉桥成桥后可充分利用斜拉索的材料强度进行补张拉工作后再进行体系转换工作,可降低主缆与主梁的高差,从而减少了吊索张拉次数和接长杆长度,体系转换方案得以优化。经ANSYS有限元模拟由斜拉桥向悬索桥的体系转换过程,其结果与设计预期目标吻合较好,给出了该方案实施下主缆、主梁、临时钢塔、主塔、吊索和斜拉索在各施工步骤下的反应,并得到以下结论:(1)"先斜拉,后悬索"的总体施工方案可解决大跨度自锚式悬索桥无法使用支架法的施工问题;(2)通过调整体系转换前的主梁线形,可大幅度降低体系转换难度;(3)对于几何非线性显著的斜拉桥向悬索桥体系转换过程中,吊索张拉方案、斜拉索力调整和拆除时机顺序等问题的确定至关重要。
When the long-span self-anchored suspension bridge crossing navigable river basin,it could not use the general support method to install the steel box girder of main span. The "first cable-stayed,then suspension"overall construction scheme is adopted. The temporary cable-stayed bridge is formed at first,then the system transformation from temporary cable-stayed bridge to self-anchored suspension bridge is carried out. Taking the 600 m ultra long span Egongyan self-anchor suspension bridge for analysis case,2independent cable support structures, i. e., the temporary cable-stayed bridge and the self-anchored suspension bridge,are coexist using unstressed state control method. The final recommended scheme is selected through system transformation scheme. Before carrying out the system transformation operation,the temporary cables are tensioned additionally by full using of the material strength after the temporary cablestayed bridge is closure. The elevation difference from the main cable to steel box girder is reduced. The assistant hanger length and the number of tensioning of suspender cable are reduced. The system transformation process is optimized. Through the ANSYS finite element simulation of the system transformation process,the analysis result is in good agreement with the design target. The reflections of main cable,girder,temporary steel pylon,main pylon,suspender cable and stay cable in different construction steps of the scheme are given. It is concluded that( 1) the "first cable-stayed,second suspension"overall construction scheme can solve the construction problem of long span self-anchored suspension bridge cannot use support method;( 2) by adjusting the geometric shape of main girder before the system transformation,the difficulty of system transformation can be greatly reduced;( 3) for the system transformation from cable-stayed bridge which has remarkable geometric nonlinear character to suspension bridge,the suspender cable tensioning scheme,the suspension cable force adjustment and demolition timing are crucial.
作者
张海顺
王玉银
ZHANG Hai-shun;WANG Yu-yin(China Railway Bridge Engineering Bureau Group Co.,Ltd.,Tianjin 300300,China;Harbin Institute of Technology,Harbin Heilongjiang 150090,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2019年第1期78-86,共9页
Journal of Highway and Transportation Research and Development
基金
天津市企业博士后创新项目(TJQYBSH2017010)
中国铁建股份有限公司科技重大专项课题项目(A18-03)
关键词
桥梁工程
体系转换
无应力状态控制法
自锚式悬索桥
临时斜拉桥
吊索
降温法
bridge engineering
system transformation
unstressed state control method
self-anchored suspension bridge
temporary cable-stayed bridge
suspender cable
cooling method
作者简介
张海顺(1984-),男,天津人,博士,高级工程师.(zhangyibiao_0216@163.com).
