西宁至成都高速铁路拉脊山选线研究

Research on Route Selection of Lajishan Section of Xining-Chengdu High-speed Railway

西宁至成都铁路穿越祁连山脉余脉拉脊山地段,该区域弱成岩工程水稳性地质问题非常突出,尤其是铁路勘察阶段遇到的高压CO2气体,国内尚属首例,可供借鉴的工程经验十分有限。如何科学、经济、安全、合理地进行地质选线及工程设置,成为控制铁路前期线路方案的重难点。本文通过开展地质专题勘察,查明不良地质分布的特征及特性,并借鉴兰渝铁路的施工经验,平面上绕避高压气体的影响,减少通过弱成岩的段落,纵断面上尽量抬高线位,避免弱成岩遇水崩解的发生,有效解决了线路平纵断面的设计难题,可供类似特殊复杂地质条件下线路方案的选择参考借鉴。

Xining-Chengdu high-speed railway passes through Lajishan section of Qilian Mountains,where the water instability problem of weak diagenetic engineering is very prominent,in particular,it is the first case in China to encounter the high pressure CO2 gas during the railway survey stage,therefore there is few of engineering experience available for reference.How to select the geological route and set up the project scientifically,economically,safely and reasonably becomes the important and difficult points of controlling the railway route scheme in the early stage.The design difficulties of the railway's plane and vertical sections are effectively resolved in this paper by finding out the characteristics of the distribution of unfavorable geology through special geological survey,and using the construction experience of Lanzhou-Chongqing railway for reference that the route bypasses the high pressure gas in the plane section,tries not to pass through the weak diagenesis sections,and raises the route position as much as possible in the vertical section so as to avoid the collapse of weak diagenesis due to water,which can effectively solve the design problem of horizontal and vertical section and provide reference for the route selection under similar special and complicated geological conditions.