新白沙沱长江六线特大桥桥面布置方案研究

Study on Arrangement Scheme of New Baishatuo Six Lines Yangtze River Bridge of Chongqing-Guiyang Railway

研究目的:渝黔铁路新白沙沱长江六线特大桥受控于地形、通航、行洪、环保、桥位等诸多因素,主桥采用(81+162+432+162+81)m六线桥跨越长江。在世界范围内,目前还没有六线Ⅰ级铁路大跨度桥建成的实例,结合线路条件、桥梁工程的情况,进行桥面布置方案研究。研究结论:(1)基于经济性、景观效果、施工便利性以及桥位条件等因素,主桥推荐采用钢桁梁斜拉桥方案;(2)根据两端线路条件,并在国内外公铁两用大桥建设调研的基础上,确定了六线分层"上4下2"的总体布置方案;(3)比较了三片主桁倒梯形断面方案、两片主桁外设托架断面方案、两片主桁倒梯形断面方案、两片主桁矩形断面方案,研究结果表明,最优的桥面布置为两片主桁矩形断面正桁方案;(4)本研究成果可为多线铁路桥梁或者公铁两用桥梁设计提供参考。

Research purposes： New Baishatuo Six Lines Yangtze River Bridge of Chongqing - Guiyang Railway is controlled by terrain, navigation, flood flowing, environmental protection, bridge site and so on, and the main bridge adopt （81 ＋ 162 ＋432 ＋ 162 ＋ 81 ） m six lines bridge across Yangtze River. In the world scope, large span bridge of six lines railway has not been constructed yet. Combined with the line conditions and bridge engineering, the arrangement scheme of bridge was studied. Research conclusions：（ 1 ）Based on the factors, such as economy, landscape effect, convenient construction, the site condition and so on, it was recommended to adopt steel truss girder cable -stayed bridge scheme. （2）Based on line conditions, and based on the highway- railway bridge construction investigation at home and abroad, it was confirmed that ＂up 4 down 2＂ of six lines railway on two layers is the optimal scheme. （ 3 ） Inverted trapezoidal section scheme with 3 main trusses, bracket section scheme with 2 main trusses, inverted trapezoidal section scheme with 2 main trusses, rectangular section scheme with 2 main trusses were compared, and the research results show that rectangular section scheme with 2 main trusses is the optimal solution. （4）The research results can provide a reference for the design of multi line railway bridge or highway -railway bridge.