隆叙铁路沱江特大桥主桥方案比选研究

Comparison and Selection of Main Bridge Schemes of Tuojiang River Bridge on Longchang-Xuyong Railway

隆叙铁路设计标准为客货共线单线铁路,沱江特大桥是本项目控制工程。主桥一次建成双线,引桥预留双线条件。桥梁受珍稀特有鱼类保护区环保要求、通航及行洪等因素控制。从通道选择、环保要求、站位条件、工程条件等各方面对桥位进行分析对比,得出并行高速公路方案最优的结论;从技术特点及施工难度、工程规模及经济性、工期、可维护性、环保、景观等各方面对桥式进行计算及分析对比,结果表明(146+292+146)m单索面矮塔斜拉桥最优。推荐方案采用的W形截面混凝土梁,具有传力构造简单合理、施工相对方便、经济性佳等优点,本桥建成后将成为国内首座采用W形梁部截面的铁路斜拉桥,也将是国内最大跨度的铁路单索面斜拉桥。

Longchang-Xuyong Railway is a mixed passenger and freight railway with single track.Tuojiang Bridge is the control project.The main bridge is built with double track at a time,and double track conditions are reserved for the approach bridge.Environmental protection requirements,navigation and flood discharge are the controlling factors of the bridge.The bridge site is analyzed and compared from the aspects of channel selection,environmental protection requirements,station conditions and engineering conditions,which draws the conclusion that the parallel expressway scheme is optimal.The bridge type is analyzed based on the calculation and comparison in terms of technical characteristics,construction difficulty,project scale and economy,construction period,maintainability,environmental protection and landscape.The results show that(146+292+146)m cable-stayed bridge with single cable plane is the best.The W-section concrete beam recommended in the scheme has the advantages of simple and reasonable transmission structure,relatively convenient construction and good economy.After completion,the bridge will become the first railway cable-stayed bridge with W-shaped beam section and also the largest span railway single cable-stayed bridge in China.