超大跨径悬索桥主缆刚度对成桥线形的影响

Impact of Bending Stiffness of Main Cables on Geometric Shape of Completed Bridge of Very Long Span Suspension Bridge

以主跨3 300 m的超大跨径公铁两用悬索桥的设计方案为研究对象,根据已有文献的研究成果得出了超大跨径悬索桥主缆截面实际抗弯刚度的取值区间,分别做了考虑主缆抗弯刚度的几何非线性有限元法和完全忽略抗弯刚度的悬链线解析法的找形计算。对比分析表明:完全忽略主缆抗弯刚度对其线形和轴力的计算结果影响甚微;主缆抗弯刚度对施工控制参数有显著影响,不容忽略。

Taking the proposed design of a very long span rail-cum-road suspension bridge with a main span 3 300 m as the research object and with reference to the research findings in the existing literatures,the authors arrive at the value selection range for the actual bending stiffness of main cable cross sections of such type of the bridge and respectively make the shape-finding calculation of main cables,using the geometric nonlinearity finite element method that takes into account of the bending stiffness of the cables and using the catenary solution method that completely neglects the bending stiffness.The comparative analysis of the calculation demonstrates that the impact of complete negligence of the bending stiffness on the calculation results of the geometric shape and axial force of the cables is quite slight,however the impact of the bending stiffness on the parameters of construction control is significant,which allows of no negligence.