哪吒大桥主缆架设施工影响因素分析

Analysis on the Influence Factors for the Main Cable Construction of Nazha Bridge

悬索桥主缆架设精度主要取决于正确的空缆状态确定和架设过程中准确的参数控制。通过计算哪吒大桥的主缆空缆线形,分析主缆无应力索长变化、温度变化、跨径变化和预抬高量等4种施工因素对哪吒大桥主缆各跨跨中标高的影响,得出结论:主缆架设的4种施工影响因素对主缆跨中标高的影响基本成线性关系;主缆架设的施工影响因素是相互作用且同时存在的,在主缆架设及空缆线形调整时应综合考虑上述因素的影响,进行必要的主缆空缆线形调整及修正工作。计算所得的空缆线形理论值及4种施工因素对主缆跨中标高的影响关系可用于指导哪吒大桥主缆架设的施工。

The construction accuracy of main cable of suspension bridge depends on the correct state of the stressless cable and the accurate parameters control under construction.Through calculation of the stressless main cable shape of Nazha Bridge with the finite element software,the authors analyze influences of the four main construction factors to the elevation of the middle span of the main cable.The factors include the change length change,temperature change,span change and pre-rising displacement of the stressless main cable.The calculation results show that the middle span’s elevation is liner with the four construction factors,and the four construction factors are interaction and simultaneous existence for each other.So those factors should be synthetically considered and necessarily modified under construction.The four construction factors and theoretical value of the stressless cable shape can guide construction of Nazha bridge’s main cable.