基于无应力长度目标的平行钢绞线斜拉索张拉方法

发布时间：2018-01-07 02:05

本文关键词：基于无应力长度目标的平行钢绞线斜拉索张拉方法　出处：《中国公路学报》2017年02期 　论文类型：期刊论文

【摘要】：为改善斜拉桥平行钢绞线拉索以索力控制张拉时需多次重复张拉的复杂操作工序,并减少由此产生的累计误差,同时使得张拉完成后每股钢绞线拉力分布更均匀,选择以钢绞线的无应力长度作为控制张拉的对象,设计了以无应力长度控制钢绞线逐根一次张拉到位的施工方案,并对其进行优化。考虑拉索的几何非线性,建立单根钢绞线的几何状态方程,确定其在目标索力下控制张拉的无应力长度;在实际施工中以该无应力长度控制张拉单根钢绞线,运用分阶段局部寻优的数值方法,考虑实际施工误差和塔、梁变形等因素,对实际施工索力与设计目标索力之间存在的误差进行修正,寻求对应实际工况的控制张拉无应力长度,以实现一次张拉到位、张拉完成后每根钢绞线拉力相等且成桥索力也更精确的目的;最后,通过计算机仿真算例模拟实际工况进行验证。结果表明:对给定的设计成桥目标索力,采用无应力长度控制张拉方案可一次张拉到位,考虑施工误差进行优化后控制张拉的无应力长度与对应实际工况的无应力长度相差较小,经过二次优化后,施工张拉索力与设计目标索力的相对误差为0.72%,且张拉完成后每根钢绞线拉力相等,满足施工要求;相关计算程序经固化后嵌入智能千斤顶可用于斜拉索张拉施工。
[Abstract]:In order to improve the complex operation procedure of cable tension control by cable force in cable-stayed bridge, the complex operation procedure of tension should be repeated many times, and the accumulative error caused by it should be reduced. At the same time, the tension distribution of steel strands per share is more uniform after the tensioning is completed, and the non-stress length of the strands is chosen as the object to control the tensioning. In this paper, the construction scheme is designed to control the length of the steel strand by one stretch to the end, and it is optimized. Considering the geometric nonlinearity of the cable, the geometric state equation of a single strand is established. The stress-free length of tension controlled by the target cable force is determined. In the actual construction, the unstressed length is used to control the tensioned steel strand, and the numerical method of local optimization is used to consider the actual construction error and the deformation of the tower and beam. The error between the actual construction cable force and the design objective cable force is corrected, and the control tensionless length corresponding to the actual working condition is sought in order to realize the primary tension in place. After the tensioning is completed, the tension of each strand is equal and the cable force of the bridge is more accurate; Finally, a computer simulation example is used to simulate the actual working conditions. The results show that the tension scheme can be used to control the tension in a single time for a given design of the bridge target cable force. The difference between the unstressed length of the control tension and the corresponding non-stress length of the actual working condition is small after the optimization of the construction error, after the secondary optimization. The relative error between the construction tension force and the design objective cable force is 0.72, and the tension of each strand is equal after the tension is completed, which meets the construction requirements. The relevant calculation program can be used in cable tension construction after solidification and embedded intelligent Jack.
【作者单位】：同济大学土木工程学院;上海市政工程设计研究总院(集团)有限公司;
【基金】：国家重点基础研究发展计划(“九七三”计划)项目(2013CB036303)
【分类号】：U445.4
【正文快照】： 0引言平行钢绞线斜拉索在国外大跨径斜拉桥中应用较广泛,如法国诺曼底大桥、西班牙卢纳桥等,都采用了平行钢绞线斜拉索;近年来,中国平行钢绞线斜拉索的应用也日益增多,如福建青州闽江大桥、芜湖长江大桥等。钢绞线拉索得以广泛应用在于其诸多优点:一方面,与平行钢丝索相比[1],

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