无应力长度正装迭代法在无背索斜拉桥工程中应用  

Application of Cable-stayed Bridge without Backstay of Forward Iterative Method Based on Unstressed Length

作　　者：马楠[1] 陈砚[1] 朱锋[2] MA Nan;CHEN Yan;ZHU Feng(CCCC First Highway Consultants Co. ,Ltd. ,Xi'an Shaanxi 710075 ,China;MIDAS Information Technology Co. ,Ltd. ,Beijing 100000,China)

机构地区：[1]中交第一公路勘察设计研究院有限公司,陕西西安710075 [2]北京迈达斯技术有限公司,北京100000

出　　处：《公路交通科技》2019年第5期64-68,共5页Journal of Highway and Transportation Research and Development

基　　金：国家科技支撑计划项目(2014BAG05B05)

摘　　要：在斜拉桥施工过程中,每次张拉的斜拉索都会对其他斜拉索产生复杂的影响,通常采用倒拆法、倒拆-正装法及无应力状态法均存在不同程度的不闭合问题,不容易求解到合理的施工过程索力。为研究确定无背索斜拉桥施工时合理施工状态的方法,以一座主跨180 m无背索斜塔单索面钢混组合斜拉桥为例,采用Midas Civil基于无应力长度结合正装迭代思路建立成桥阶段和施工阶段有限元分析模型。首先根据初始索力求解出无背索斜拉桥初始无应力长度,然后依据最小二乘原理通过多次正装迭代分析,使斜拉桥施工最终状态和成桥目标状态差异达到允许范围内,求解得斜拉桥合理施工状态的索力值。通过实例证明,基于无应力长度正装迭代法可以较好地解决无背索斜拉桥施工正装分析的不闭合问题,完成索力优化,满足工程精度要求。对无背索斜拉桥合理成桥状态索力及合理施工过程索力优化提供了一定参考,具有一定的推广价值。During the construction of cable-stayed bridge, tensioning stay-cable each time will produce complex influence to the other stay-cables, the results of back running method, forward-back optimization method, stress-free state method show various of non-close problems.It is uneasy to solve the reasonable cable force in construction process through these methods.To research the reasonable construction method of cable-stayed bridge without backstay, taking a cable-stayed bridge with 180 m main span without backstay for example, the Midas Civil program is used to establish the FE analysis models of bridge completion stage and construction stage based on unstressed length and forward iterative calculation.First, the initial stress-free length is solved according to the initial cable force.Then, through several forward iteration analysis by the principle of least squares, the difference between the final construction state and the target state of the completed bridge is controlled within the allowable range.Finally, the cable force value of the reasonable construction state is solved.It is proved by the example that the non-closed problem of forward calculation method for the cable-stayed bridge without backstay can be well solved by the forward iteration method based on unstressed length so as to complete cable tension optimization and satisfy the engineering demand.It provides a certain reference for the reasonable cable force of completion state and the optimization of the cable force in the construction process, and has certain promotion value.

关 键 词：桥梁工程 无应力长度 施工控制 无背索斜拉桥 正装迭代 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U445.1[交通运输工程—道路与铁道工程]