沙田大桥基索垂度调整及关键参数敏感性分析

Sag Adjustment of Datum Cable Strand of Shatian Bridge and Sensitivity Analysis of Key Parameters

基准索股垂度调整是悬索桥施工过程中的关键控制工序,本文以沙田大桥为工程背景,采用Midas/Civil有限元软件对全桥进行了仿真化建模,并据此对其基准索股架设过程中的垂度调整及其垂度调整过程中的相关参数进行了敏感性分析;根据基准索股无应力长度在施工过程中始终保持不变的原则及温度、跨度和塔高等关键性参数对基准索股垂度调整的影响规律推导出其垂度调整公式。经相关实测数据验证,该垂度调整公式具有较高的精度和可靠度,可用于大跨度悬索桥基准索股架设指导施工。同时在施工过程中需要时刻重点关注温度、跨度和塔高等关键性参数并做出及时调整,以确保基准索股的架设精度。

The sag adjustment of reference cable strand is the key control process in the construction of suspension bridge.Taking Shatin bridge as the engineering background,this paper uses Midas/civil finite element software to analyze the sensitivity of sag adjustment and relevant parameters in the process of sag adjustment during the erection of benchmark cable strand.Then,according to the principle that the unstressed length of the reference cable strand remains unchanged during the construction process and the influence law of the key parameters of temperature,span and tower height on the sag adjustment of the reference cable strand,the sag adjustment formula is deduced.Verified by the relevant measured data,the sag adjustment formula has high accuracy and reliability,and can be used to guide the construction.