研究目的: 虎跳峡金沙江大桥为丽香铁路的重点控制性工程。大桥桥址位于环境敏感区、高烈度地震区 及断裂发育带,需要综合线路走线、环保、地形、地质情况及金沙江中游水电开发规划的影响,选择虎跳峡金沙 江大桥的合理桥位及桥式方案。
研究结论: (1)虎跳峡金沙江大桥的8号桥位416 m上承式钢桁拱桥是最优的工程方案,27号桥位(98 + 660 + 98) m钢桁梁悬索桥可以为规划中的水电开发预留条件,整体上经济、社会效应更好;(2)上承式钢桁拱 桥承载能力高、刚度大、造型优美,适用于高山峡谷地形,但其拱肋位于结构下方,影响桥下蓄水及通航;(3) 钢桁梁悬索桥抗震性能好,结构刚度能满足铁路列车的行车要求;(4)研究成果对于高山峡谷区大跨度铁路 桥梁的桥位桥式比选有较好的借鉴意义。
Research purposes:The Hutiaoxia Jinsha River Bridge is the key project of Lijiang - Xianggelila Railway and is located in the sensitive environmental and high seismic intensity region with the active fault. The reasonable bridge site and type should be selected for this bridge on consideration of the railway alignment, environment protection, topography,geological condition and the plan of hydraulic engineering on the midstream of the river.
Research conclusions:(1) Using the deck type steel braced arch at the No, 8 bridge site(416m) of the Hutaioxia Jinsha River Bridge is the best engineering plan. Using the steel truss suspension bridge at No. 27 bridge site (98 + 660 + 98 m) can remain the condition for the hydroelectric plan of river and can get the better economic and social benefits. The deck type steel braced arch has features of the good load bearing capacity, good rigidity and nice looking and is suitable for the high mountain and deep valley area,but it produces the impact on the water storage and shipping under bridge because the arch rib is installed on bottom of the structure. (3)The steel truss suspension bridge has the features of the fine anti - seismic performance and good rigidity to meet the train requirement. (4) The research result can provide the reference to the type selection of the large span railway bridge in mountain and deep valley area.