【作者】 蒋伟平；

【导师】 李亚东；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2003， 硕士

【摘要】 过去50年内，全世界修建了300余座斜拉桥，由于斜拉索的防护技术不尽完善，在运营若干年后，不可避免地会出现斜拉索腐蚀问题，国内外一些斜拉桥不得不面临换索的问题。因此，斜拉桥换索成为非常具有工程实践意义的课题。 通过换索对原桥的线形与内力进行改善，是换索设计主要目标，但换索设计如果未能准确地模拟换索前结构的线形与索力(内力)状态，就会导致换索完工后结构的线形与索力与设计目标值相差较远。本文首先以索力优化理论为基础，利用最小余能原理，建立了通过换索改善结构线形与内力的理论和方法。然后以四川犍为岷江大桥换索工程为背景，以换索前实测的索力和线形为换索设计基准，应用西南交通大学开发的桥梁结构分析软件BSAS建立换索分析模型，通过调索等技术手段使模型索力与换索前实测索力逼近，以此为换索的出发点，按原换索设计的方案与工序，对换索进行全过程分析，得到换索完工后的计算索力和线形。与原设计结果相比，本文得到的索力与线形更接近换索后实测的索力与线形，表明准确地模拟结构换索前的线形与索力(内力)状态对换索设计至关重要。最后，对换索工程的施工技术、工艺进行了总结与探讨。更多还原

【Abstract】 In the past 50 years, about 300 cable-stayed bridges have been built in the whole world. Owing to the imperfect cable protection technology, cable corrosion is unavoidable after the bridge served a few years. In the world, a few cable-stayed bridges have to face the problem of being cables replaced. So, the engineering significance of cable replacement is great.The main objective of cable replacement design is to improve bridge geometry and internal forces of primary bridge by replacing cables. If failed to simulate the actual status of primary bridge in the design, which will result in the bridge geometry and cable forces differ desired value greatly after cable replacement work is finished. In this thesis, based on cable forces optimization theory, utilizing minimal remnant energy principle, the theory how to improve bridge shape and internal forces of primary bridge by replacing cables is founded. And in combination with cable replacement engineering of Sichuan Qianwei Bridge, based on the bridge elevation and cable forces measured before cable replacement started, using finite element software BSAS developed by Southwest Jiaotong University build analysis modeling, by means of cable forces adjustment and so on to make the cable forces of modeling approach the cable forces measured before cable replacement started, according to the scheme of primary design, aimed at cable replacement process, simulation analysis is done and get the calculated results. Compared with the primary design results, the calculated results in this thesis coincide better with the measured results after cable replacement is finished, which demonstrates that simulating the actual status of primary bridge accurately is very important to cable replacement design. Finally, construction techniques and crafts for cable replacement arc summed up and discussed.更多还原