大跨度斜拉桥斜拉索无应力长度计算方法
Calculation Method for Unstressed Length of Stay Cables in Long-span Cable-stayed Bridges

通过对影响斜拉索无应力长度的施工阶段各种因素的敏感性参数进行分析，确定了影响斜拉索无应力长度的显著因素；综合各种影响因素，建立了斜拉索无应力长度精确计算方法。结果表明：主塔的预偏位、主塔的动态变位、主梁的预拱度、主梁的预抬高、主梁的动态变位、温差、斜拉索弹性模量误差以及计算斜拉索弹性伸长修正值所选用的荷载均为敏感性影响因素；建议的方法可以精确地计算斜拉索的无应力长度，避免出现长索无法调整索长的状况。
The sensitivity parameters of various factors that influenced unstressed length of stay cables in different construction stages were analyzed and the most important influence factors were confirmed. Considering various influence factors, the calculation method for unstressed length of stay cable was given. The results show that the pre-deviation and dynamic displacement of main towers, pre-camber, prearranged height and dynamic displacement of main girders, temperature difference, elastic modulus error of stay cables, the load values which are used to calculate modified elastic elongation of stay cables are all the most sensitive factors. The proposed method can accurately calculate the unstressed length of stay cables, and avoid the situation that the length of long cables cannot be adjusted