南沙港铁路鸡鸦水道公铁合建段线间距研究

Research on Line Spacing in Highway and Railway Combined Section of Jiya Waterway Bridge on Nansha Port Railway Line

以南沙港铁路鸡鸦水道公铁合建段为研究对象,研究了不同的线间距选取对铁路工程的重大影响。首先系统研究了过鸡鸦水道段17 m变线间距与4 m区间线间距两个方案,通过桥梁受力检算与偏心计算知17 m变线间距方案能最大限度利用既有公路桥墩,但施工过程对水道航迹线产生影响;4 m线间距方案可最大程度节省土地占用,同时优化水道航迹线,故选择后者。此后,根据超高、纵断面等合理计算过渡交点曲线加宽值以减少夹心地;最后,得出结论:科学的线间距选择对于与公路建设时序不同步的特殊铁路工程意义重大。

By taking the highway and railway combined section Jiya Waterway Bridge on Nansha Port railway line as the research object, this paper studies influences of different line spacing selecting on the project con- struction. Firstly, two schemes of 17m variable line spacing and 4m line spacing for Jiya Waterway Bridge are researched systematically. After testing the stress of the bridge and calculating the eccentricity, it finds out that the scheme of 17m variable line spacing can maximize the use of bridge piers for the existing highway, but the construction process has effects on sailing tracks of the waterway. Meanwhile, the scheme of 4m can lessen land use to the maximal degree and optimize the sailing tracks of the waterway, which is adopted accordingly. Fur- thermore, this research calculates the curve widening values of transition intersections reasonably to reduce land use according to the superelevation and profile. It concludes that selecting the line spacing scientifically is of great significance for the special railway project with the highway construction constructed in different periods.