2003 Volume 13 Pages 423-428
We are developing a new technique of building a large tunnel by piling up small shield tunnels, as a way ofmaking underpasses at the intersection between a railway and a roadway, or between two roadways.
A tunnel is divided into several sections as if mouthpiece of a harmonica and each section is built individually, and then they are connected together. The miniaturization of machines makes it possible to build a tunnel which is shallow ground. Moreover, during the execution it does not significantly damages the ground, because of its cross-sectional structure. Since they are built partly, it eases traffic congestion. It is also suitable for a long distance or a curve-lined section.
