大瑞铁路澜沧江特大桥施工关键技术研究

Research on the Key Construction Technology of the Lancang River Super Major Bridge on Dali-Ruili Railway

澜沧江大桥为大理至瑞丽铁路跨越澜沧江的一座特大桥梁,桥梁位于澜沧江峡谷内,建设条件困难。结合地形、地质及交通条件,确定采用主跨为342 m的上承式钢筋混凝土拱桥桥式方案,通过计算分析和对既有技术的调研,提出并实施二次竖向转体的拱肋钢劲性骨架施工方案。通过有限元计算模拟拱肋外包混凝土的施工过程,对比多种外包混凝土分段浇筑方式后,最终采取受力最好的“四环多工作面”拱肋外包混凝土方案,成功解决了地形陡峭地区混凝土拱肋安装技术难题,进一步拓展了混凝土拱桥的适用范围。

The Lancang River is a super major bridge on Dali-Ruili Railway.The bridge is located in the valley of Lancang River with difficult construction conditions.According to the terrain,geological and traffic conditions,the bridge is designed as a reinforced concrete arch bridge with main span of 342 m.By calculation and investigation of existing technologies,the construction scheme of steel stiff skeleton of arch rib is proposed and implemented by secondary vertical rotation method.The construction process of arch rib concrete is simulated by finite element analysis method.The scheme of“four rings and multiple working faces”is adopted after comparing several methods of concrete segmental pouring.As a result of these construction methods,the construction problems of concrete arch bridges in difficult mountainous areas are solved and the application scope of concrete arch bridge is further extended.