Analysis of groundwater seepage of tunnels in fractured rock

Two approaches, the equivalent porous media (EPM) approach and the discrete fracture media (DFM) approach, are used to predict the groundwater seepage into the tunnel in the fractured formation. Result of simulation indicates that the predicted flow rates of both approaches have drastic discrepancie s. It shows that an additional tunnel which is excavated underneath the ori ginal tunnel is more helpful to minimize the groundwater flow flushing out of an original tunnel than one which is excavated in other directions.