研究结论：引江济淮工程是关系国计民生的国家重点工程,江淮沟通段有4条线与铁路交叉需要进行改建,从南至北依次为合九铁路、宁西铁路下行线、沪蓉铁路和宁西铁路上行线。本文在阐述引江济淮工程及其涉及的铁路线路概况的基础上,从利用既有设备设施、减少过渡过程、减少对既有线影响等多方面进行综合分析,针对拟建引江济淮工程与既有宁西下行线交叉存在的问题进行多方案技术经济比选研究,并在这些工作的基础上重点研究改线方案和原位改建方案。
研究结论：(1)原位改建方案由于巧妙地利用了相邻废弃的既有沪蓉铁路进行施工过渡,技术经济优势明显,因此推荐采用原位改建方案;(2)对该项目的技术创新和设计优化进行了总结,在设计方法和设计思路方面可为既有线改建提供经验。

Research purposes: The diversion project from Yangtze River to Huaihe River is a national major engineering project related to the national economy and residents′ livelihood. 4 lines in the Jianghuai communication section intersect with existing railways. Down from north, they are Hefei-Jiujiang Railway, the downlink of Nanjing-Xi'an Railway, Shanghai-Chengdu Railway and the uplink of Nanjing-Xi'an Railway respectively. On the basis of expounding the general situation of the river diversion project and the railway lines involved, this paper made a comprehensive analysis from thepoints of the use of existing equipment and facilities, reducing the transition process, and reducing the impact on the existing line, and conducted a multi-scheme technical and economic comparison and research on the problems existing in the proposed diversion project from Yangtze River to Huaihe River and the existing Nanjing-Xi'an Railway downlink. Based on these works, the research focused on the line remodeling scheme and the in-situ reconstruction scheme.
Research conclusions: (1) The in-situ reconstruction scheme is chosen due to its ingenious use of the adjacent abandoned Shanghai-Chengdu Railway for transition during construction, which has significant technical and economic advantages. (2) The technical innovation and design optimization of the project are also summarized, which provides experience for the existing railway reconstruction in terms of design methods and design ideas.