Abstract: The main cable state is an important control index in the construction process of suspension bridge, and it is the main factor influencing the accuracy of bridge alignment. Taking a highway-rail suspension bridge under construction as an example, five parameters during erection were selected, including main cable temperature, tower pre-lift value, elastic modulus of steel wire, diameter of steel wire, and weight error of steel truss beam. The influence of the above parameters on the main cable state was analyzed. The research results show that the main cable temperature, tower pre-lift value, elastic modulus of steel wire and weight error of steel truss beam during erection have a great impact on the empty cable alignment, which are highly sensitive factors. The elastic modulus of steel wire has a great influence on the unstressed length of the main cable, which is a highly sensitive factor. The diameter of steel wire has a certain impact on the empty cable alignment, which is a generally sensitive factor. The weight error of steel truss beam has a certain impact on the internal force of completed main cable bridge, which is a generally sensitive factor. In order to improve the erection accuracy of the main cable of suspension bridge, it is necessary to accurately obtain the relevant influencing parameters and feed them back to the monitoring work.

Key words: bridge engineering; road-rail suspension bridge; main cable status; parameter sensitivity; finite element analysis

摘要： 主缆状态是悬索桥建设过程的重要控制指标，是影响桥梁线形精度的主要因素。以一座在建的公轨两用悬索桥为例，选取架设时主缆温度、桥塔预抬值、钢丝弹性模量、钢丝直径、钢桁梁重量误差等5个参数，分析以上参数对主缆状态的影响。研究结果表明：主缆架设时主缆温度、桥塔预抬值、钢丝弹性模量、钢桁梁重量误差对空缆线形影响较大，为高敏感性因素；钢丝弹性模量对主缆无应力长度影响较大，为高敏感性因素；钢丝直径对空缆线形有一定影响，为一般敏感性因素；钢桁梁重量误差对主缆成桥内力有一定影响，为一般敏感性因素。为提高悬索桥主缆架设精度，需准确获取相关影响参数并反馈到监控工作中。

关键词: 桥梁工程；公轨两用悬索桥；主缆状态；参数敏感性；有限元分析