Apparatus for, and a method of, driving tunnels

摘要

Tunnel driving apparatus has a shield with a plurality of cutter planks arranged side-by-side around the tunnel axis. The planks are supported and guided by two frames connected via a rigid bracing structure. One of the frames is provided with adjustable means capable of expanding or contacting the frame radially of the tunnel axis. The planks are advanced in known manner individually or in groups and the adjustable frame can be used to make the axes of the planks converge rearwardly of the tunnel driving direction when desired. Such control permits steering of the apparatus by making the reactive forces on the advancing planks cant the shield within a tapered gap between the planks and the tunnel wall. In addition the tendency of the frames to become jammed in the planks when being shifted up can be precluded.