Development of GIS system for Predicting Tunnel Inflow and Dewatered Area

Abstract

Recently, an environmental impact on water resources due to tunnel excavation is becoming one of the serious issues associated with tunnel construction. The authors have developed a computer aided system to predict tunnel water inflow as well as the possible dewatered area during and after construction of a tunnel. The developed system uses a conventional approach, so called Takahashi's method. By utilizing GIS, Geographic Information System, the evaluation processes, such as watershed delineation and calculation of influenced area, are conducted semi-automatically. The system does not require professional knowledge on topographic analysis and the tunnels at any location can be analyzed using a built-in DEM (Digital Elevation Model) data covering whole Japan. The reliability of the developed system was confirmed by using an example of a real tunnel shown in the Takahashi's paper.