基于无应力状态法的大跨钢管混凝土拱桥拱肋线形控制方法  

Geometry Control Method Based on Stress-Free State Theory for Long-Span Concrete-Filled Steel Tube Arch Bridge

作　　者：吴海军[1] 何立 王邵锐[1] 李金权 陆萍[1] WU Hai-jun;HE Li;WANG Shao-rui;LI Jin-quan;LU Ping(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Sichuan Road&Bridge(Group)Co.,Ltd.,Chengdu 610041,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]四川公路桥梁建设集团有限公司,四川成都610041

出　　处：《桥梁建设》2020年第6期20-26,共7页Bridge Construction

基　　金：国家自然科学基金项目(51608080);重庆市教委科学技术研究项目(KJ1600507)。

摘　　要：钢管混凝土拱桥采用无支架缆索吊装斜拉扣挂法施工时,拱肋各节段的尾索、扣索索力和预抬高值是其成拱线形的关键影响因素,也是各节段精准定位的重要指标。针对实际工程在拱肋节段空间定位时可能存在的问题,提出动态修正节段控制点位置的拱肋节段定位方法,避免施工中不确定性因素对成拱线形造成偏差,使拱圈线形光滑平顺;针对目前计算方法的局限性,提出基于影响矩阵快速计算节段索力及预抬高值的方法,利用无应力状态法进行施工控制,实现成拱线形逼近目标线形;以车辋大桥为工程背景,利用MIDAS Civil有限元软件对该桥拱肋安装过程进行仿真模拟。结果表明:拱肋线形控制方法、索力及预抬值计算方法可行,且计算精度较高,实测拱肋线形和拱轴线偏位均满足规范要求。The arch ribs of concrete-filled steel tube(CFST)arch bridge are commonly constructed by using the cable-stayed cantilever assembly method,with no support of scaffoldings.The forces of anchor cables and fastening cables as well as the pre-raising values of each arch rib segment are the key influential factors of the geometry of the arch rib in complete state,and also the key indexes for accurate positioning of each segment.In view of the problems that may occur in the spatial positioning of arch rib segments in practical engineering,the positioning method which allows dynamical modification of the position of segment control points is proposed to avoid the deviation of the arch geometry caused by uncertain factors in construction and smooth the arch ring geometry.Moreover,to address the limitations of the existing calculation methods,a method based on influence matrix that can rapidly calculate the cable forces and pre-raising values of arch rib segments is proposed,based on which the stress-free state method can be used for construction control to make sure that the geometry of the arch ribs in complete state could meet the target level.The Chewang Bridge is applied as a case,the installation process of the arch ribs of which was numerically simulated by MIDAS Civil.The results show that the method used to control the arch rib geometry and the method used to calculate cable forces and pre-raising values of arch segments are feasible and of high calculation precision.The measured arch rib geometry and the deviation of the arch axis can meet the code requirements.

关 键 词：拱桥 钢管混凝土结构 线形 索力 预抬值 无应力状态法 有限元法 施工控制 

分 类 号：U448.22[建筑科学—桥梁与隧道工程] U445.4[交通运输工程—道路与铁道工程]