城际轨道交通大跨度矮塔斜拉桥设计关键参数研究

Research on Key Design Parametrers for Extradosed Cable-stayed Bridge of Intercity Rail Transit

随着轨道交通建设区域的不断延伸,大跨度桥梁越来越多地应用于轨道交通领域。由于矮塔斜拉桥属于高次超静定复杂结构,刚度、温度耦合效应明显,控制设计参数多,同时轨道交通桥梁的荷载、刚度、变形等指标与公路桥梁有所不同。针对南京市宁句城际轨道交通大跨度矮塔斜拉桥,通过对各关键参数的比选分析,得出该桥的主要结构参数对结构力学性能的影响规律。研究结果表明:矮塔斜拉桥的受力性能受主梁刚度影响较大,而受桥塔的刚度影响较小,增大桥塔高度、拉索间距和塔根无索区长度将改善结构的受力性能。

With the continuous extension of the rail transit construction area,long span bridges are increasingly used in rail transit.Extradosed cable-stayed bridge is a complex indeterminate structure.Thus,the stiffness and temperature coupling effects are significant.There are many controlling design parameters.Also,the bridge of rail transit is different from that of road in terms of loads,stiffness and deformation.The extradosed cable-stayed bridge of Nanjing-Jurong intercity rail transit was studied in this paper.Through the comparison and analysis of the key parameters,the influences of the key structural parameters on the mechanical performance were studied.The results show that the performance of the extradosed cable-stayed bridge is influenced by the stiffness of the main girders rather than that of the bridge tower.The structural behavior may be improved through the increase of tower height,cable spacing and the length of non-cable area at the root of the tower.