Abstract:

The groundwater investigation for a tunnel on YichangWanzhou railway by using NaCl as an artificial tracer is presented in the paper. The relationship between the water gushing in the tunnel and the underground rivers is analyzed. By measuring the electrical conductivity and chloride concentration of the water at the monitoring points, the direction of XiaomatanLongtanKemakou underground river is determined and it is verified that there is no direct relation between the water gushing in the tunnel and the underground river.

Key words: artificial tracer test, underground river, chloride, groundwater investigation