A tunnel is an underground passageway, dug through the surrounding soil/earth/rock and enclosed except for entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube construction techniques rather than traditional tunnel boring methods. In this modern construction projects a long-term, trouble-free tunnel operation with low operating and maintenance costs is important. This can be achieved by installing GCL system or Geosynthetic clay for Tunnel construction. The sealing system will also prevent environmental damage from oils or chemicals which may occur due to traffic accidents.