五指山隧道地下水化学特征与水动力分带模式

Hydrochemistry Characteristics and Hydrodynamic Zone of Groudwater of Tunnel in Wuzhi Mountain

五指山隧道施工时面临涌水量大及动态变化强烈等复杂水文地质问题。该文调查了隧址区地质环境,分析了隧址区地下水补给、径流、排泄特征,对比分析了隧址区不同时期的地下水化学特征,以及隧址区地下水动力垂直分带。结果表明:⑴隧道涌水属于深循环地下水,进口段隧道涌水主要来自砂页岩含水层内的水,而出口段隧道涌水含有大量石膏溶滤水。⑵样品硫、氧同位素组成证实了五指山隧道主要涌水带均与浅表地下水的直接下渗有关。⑶隧道开拓过程中可以揭露到多个相互隔绝的地下水起源略有差异的含水带,而在浅表部存在一个沟通这些含水系的横向含水带将它们连接起来。

There are complicated hydrogeology problems such as a large quantity of inflow water and a great of dynamic changes during construction of the tunnel in Wuzhi mountain. These jobs were presented in this paper in details such as surveying geological environment of the tunnel area, analyzing track characteristics of groundwater and contrasting hydrochemistry characteristics of groundwater in different periods. And the hydrodynamic zones at the tunnel were also analyzed. Results show that the inflow water is circulating groundwater in the deep earth. The inflow water at the entrance of the tunnel is from the sandy shale region. And the inflow water at the exit of the tunnel is mainly composed of gypsum-dissolved water. The results also show that there are direct relation between the tunnel inflow water and the groundwater on the earth＇s surface proved by the composition of samples of sulfur and oxygen isotopes. The difference of the water-bearing zone in the isolated groundwater was disposed when the tunnel was exploited. And the transverse water-bearing zones were connected by the one at the earth＇s surface.