Nowadays, the underground of urban areas is regarded as a new space for infrastructure supply such as the provision of subway networks. In planning the route of such networks, several factors have to be considered; land use patterns and planning objectives, existing transportation networks, soil type, possible environmental impacts. Although most underground tunnels are constructed under public space, some private space has to be acquired. This compensation cost must also be considered while evaluating different possible routes. Conventional techniques for analysing the interaction of all these factors and their effect on total construction cost is tedious, inaccurate, and time consuming. In this study, a GIS-based system is developed to investigate the merits of implementing GIS into this area. The system is equipped with several spatial databases containing relevant information on a study area. An analysis module in the form of user defined subroutines is also included to handle required spatial analysis and cost evaluation. The user can interact with the system through a user-friendly interface to choose alternative routes both in the horizontal and vertical directions. A predefined set of constraints is checked by the system throughout the route selection process. Each of the routes is then evaluated both from technical and economical viewpoints and best routes are recommended. A case study is carried out using the developed system to compare several construction techniques and compensation schemes. In this case study, the route of an underconstruction subway line is replanned using this system. Analysis results are then compared with those of the planned route.
Abstract