Forecast of Groundwater Flowrate in Tunnel by Integrated Approach

When a tunnel comes through a deep beried tunnel in rocks abounding with groundwater, the most important problem is to compute the flowrate of groundwater. The key to compute the flowrate is to choose the right calculation method according to the regional hydro-geological characteristics. Based on the hydro-geological characteristics of the Dashuijing Tunnel, this paper chose three different geological dynamic methods to calculate the groundwater flowrate. The calculation result show that when the permeability reduces, the groundwater flowrate by Railway code formula and Fuluominlang method reduces in the form of index, the groundwater flowrate also reduces with an near-linear decrease by the non-uniform section two-dimensional flow formula. By considering about the non-uniform of the rock stratum in study area, we divided the area into several pieces. According to the three different methods, we forecast the groundwater flowrate in the Dashuijing tunnel by considering about the Railway code formula and the non-uniform section two-dimensional flow formula.