玉蒙铁路曲江大桥简支钢桁梁架设方案分析

玉溪至蒙自铁路曲江大桥全桥孔跨布置为3×32m简支T梁＋3×96m下承式简支钢桁梁＋1×32m简支T梁＋2×24m简支T梁，主墩最高达92m，由于受桥位地形、主跨梁部结构形式、投资、工期等因素影响，不能采用常规的钢梁架设方案，如拖拉方案、单端大悬臂拼装等方案，必须研究新的架设方案。针对该桥的特点和实际情况，介绍几种主要的架设方案，通过对不同方案的施工过程计算、辅助设施的采用情况、经济性、安全性、优缺点等多方面的比较，优选出适合曲江大桥的架设方案。并结合该桥介绍了多跨简支钢桁粱在高墩情况下的不同施工方法及特点。

ERECTION SCHEME ANALYSIS OF SIMPLY-SUPPORTED STEEL TRUSS GIRDER OF QUJIANG MAJOR BRIDGE OVER YUXI TO MENGZI RAILWAY

Piers for Qujiang Major Bridge over Yuxi to Mengzi Railway are arranged as follows: 3×32 m simply-supported T-beams ,3×96 m through-bridge simply-supported steel trussed girders,1×32 m simply-supported T-beam and 2×24 m simply-supported T-beams. The main pier is up to 92 m. Some factors such as bridge site, main span beam structure, investment and construction period make conventional steel girder erection schemes (such as launching method and single-end large cantilevered assembling construction method) impossible, so new erection schemes must be taken into consideration.Several erection schemes are introduced based on characteristics and actual conditions of the bridge, and by comparing these schemes in terms of construction calculation, use of auxiliary facilities, economy, safety, advantages and disadvantages, etc, an erection scheme suitable for Qujiang Major Bridge is chosen,and then different construction methods and characteristics of multi-span simply-supported steel trussed girder under high pier conditions based on this bridge are introduced.