成贵铁路绕避地下水水平循环带线路方案研究

Research on route scheme of Chengdu-Guiyang Railway Passing round Groundwater Level Cycling Zone

岩溶地质灾害是西南山区铁路选线的重要控制因素之一。该地区岩溶形态多样,既有溶隙、岩溶洼地、落水洞、漏斗等垂向岩溶形态,也有溶洞、暗河等水平岩溶形态。由于受构造作用影响,岩体破碎,加之测区雨量充沛,受泥质岩类的相对隔水层的夹持,从而有利于地下水的补给和对可溶岩成分的溶蚀、溶解作用,造成了该区岩溶强烈发育。本文以成贵铁路从四川盆地至云贵高原的低、中山区斜坡过渡段隧道工程为例,通过对线路绕避地下水水平循环带方案研究,综合平面选线、最大纵坡选择、岩溶危害与工程风险、工程投资、隧道施工工艺等方面进行分析、比选,确定合理的线路方案。

Karst geological hazard is one of the key controlling factors of railway line selection in southwestern mountain-ous area, where there are kinds of karst features, not only vertical karst shapes, such as solution cracks, karst depres- sions, sinkholes, dolines, but also horizontal karst features, for example, karst caves and underground rivers. Due to the effect of tectogenesis, the rock is very fragmented, in addition, plenty of rainfall and clamped by the relative imper- meable layer of pelite, it is beneficial to groundwater recharge and the dissolution of soluble rock, which cause strong development of karst stratum in this area. This paper takes tunnel projects in the slope transition section from Sichuan ba- sin to Yunnan-Guizhou Plateau of Chengdu-Guiyang railway for example, study how to avoid the groundwater horizontal cycling zone, accompany withbased on the analysis, comparison and selection of railway location, selection of maximum longitudinal slope, karst hazard, engineering risk and investment and tunnel construction technology etc, finally the best railway route scheme to avoid the groundwater horizontal cycling zone is determined.