ABSTRACT
Recent years have seen increasing use of shield tunneling, as efforts are made to utilize underground space in urban areas and their environs. In the built-up and overpopulated cities and urban areas, however, it is becoming increasingly difficult to secure space for the necessary shafts. As such, long-distance shield tunneling methods are necessary for urban tunnels because of the lack of space for the shafts and the demand for greater cost-effectiveness. High-speed tunnel construction has also become more important as a way to improve cost-effectiveness. The F-NAVI method, one of the high-speed tunnel construction methods, has a unique system that allows simultaneous excavation and segment assembly. This paper gives an outline of the F-NAVI shield tunneling method and reports on actual tunneling work using the F-NAVI.
