Abstract：During the construction of a tunnel，if no measure is adopted to prevent groundwater discharge，the movement of groundwater along tunnel axis can be ignored and the seepage movement of groundwater can be simplified to 2D movement in section after completion of the tunnel. If the size of a deep tunnel is far less than that of its surrounding aquifer，it can be treated as a point-well in section. Trial calculation is performed by putting a value of discharge，estimated by analogy，into the numerical model and by repeated increases or decrease in a certain step until the groundwater table reaches the stable state. Then a trial discharge can be obtained. The discharge of a deep tunnel in southwest China calculated by the trial method accords well with results of other methods and its significance of hydro-geology is more clear，when used together with experimental and analytical methods. The value of discharge can be calculated more precisely，and this indicates that it can be used practically.
2002, Vol. 21 
