南水北调中线工程高地下水位渠段水文地质分析

Hydro-geological analysis of canal section under high groundwater level

南水北调中线工程总干渠陶岔-沙河南段地下水位高于渠底板的渠段长约130 km,沿线岗垄、岗丘平原、河间平原、剥蚀残丘地带均有分布。这些渠段存在膨胀土(岩)渠坡处理、渠道边坡稳定、基坑涌水和涌砂、渠道衬砌抗浮稳定等问题,均与地下水有关。分析了高地下水位渠段的工程地质条件及水文地质条件,分区域对地下水补排关系及水位变化规律进行了总结,并以方城段渠道施工为例,介绍了高地下水位渠段渠道渗透破坏控制处理措施。

The canal section of Taocha to Shahe of main canal of Middle Route Project of South-to-North Water Diversion, along which the groundwater level is higher than the canal bottom plate, is about 130 km long. Along the canal line, hills, plains and eroded zones are distributed. There exist many problems in the canal section such as expansive soil （rock） slope treatment, canal slope stability, water and sand boil of foundation pit and anti-floating stability of linings, all of which are related to the groundwater. The engineering-geological condition and hydro-geological condition along the canal section are analyzed. The relationship between groundwater recharge and discharge and its level variation are summarized by zoning. The control measures for the seepage failure of the canal under high groundwater level are introduced with the case of Fangcheng section.