3D Numerical Simulation for Predicting Water Inflow Volume in Deep and Long Tunnels
(1 Department of Hydraulic Engineering, Tongji University, Shanghai 200092; 2 Anhui Transport Consulting & Design Institute Co.Ltd., Hefei 230088; 3 College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling 712100)
Abstract:
Improper treatment of water inflow in tunnel construction might lead to serious destruction to the ecologi? cal and social environments, so it is necessary to accurately predict the volume of tunnel water inflow. Using the Mingtangshan tunnel as a case study, the watershed of surface water, boundary conditions, initial conditions, generalization of fault factors and groundwater simulation methods are analyzed. A finite-difference program MODFLOW is adopted to simulate the water inflow volume for the deep-buried, long tunnel in water-bearing bedrock fissures, and the impact of tunnel construction on the surrounding groundwater environment is assessed. The results show that the instantaneous water inflow volume at fault F7 is reduced to a stable value after 1 000 days, and the calculated stable water inflow volume is close to the measured value; the influence of tunnel excavation on the adjacent groundwater environment is mainly concentrated at the tunnel axis near the fault and locally on the ridge.