Methods of and apparatus for driving tunnels

摘要

Apparatus for driving tunnels or the like employs a drive shield known per se, with drive members supported and guided on a frame. Rear extension members are linked to the drive members, preferably through units permitting relative displacement therebetween and these rear members form a rear shield for receiving supports and reinforcements for a permanent lining for the tunnel. A concrete spraying nozzle or the like applies a strip of concrete to the tunnel wall each time a rear member is shifted in the advancing direction. In this way a series of strips, preferably shape locked together at their ends, can be built up stage by stage to create the lining.