| A brief review of the water inflow problem in tunnel engineering is given. Water inflow prediction methods presently available are discussed. Hydraulic conductivity is the most important parameter in the prediction. Several methods of hydraulic conductivity estimation for rock masses are described in the thesis.;A saturated-unsaturated finite element model was established for the transient flow. The model examines situations closer to the realistic case by overcoming some unrealistic assumptions, such as a constant yield capacity and a parabolic shape of water table during the transient period. The model was simplified to Rechard's equation by considering a passive air phase from the two phase flow model. The delayed water drainage behind the water table is simulated according to the capillary law. Water inflow variations with time have been examined for some selected parameters. Water pressure distribution and water table drawndown with time are also examined. (Abstract shortened by UMI.);The analytical solution of steady state flow derived by Goodman in 1964 has been extended to including the hydraulic conductivity--depth relationship which was empirically obtained by Louis. |
