Apparatus for, and a method of, driving tunnels

Tunnel driving apparatus with a shield composed of a plurality of elongate members arranged in side-by-side relationship for contacting the wall of a tunnel, first and second frames spaced apart along the longitudinal central axis of the shield, the frames serving to support and guide the members for longitudinal displacement and adjustable means for varying the effective size of one of the frames in relation to the other to bring all the axes of the elongate members into a parallel relationship or into a relationship where the said axes converge in a rearward direction relative to the direction of tunnel advancement.

In a tunnel driving apparatus with a shield composed of a plurality of elongate members arranged in side-by-side relationship and capable of contacting and supporting the wall of a tunnel, and means supporting and guiding the members for longitudinal displacement in the driving direction;

• the improvements comprising the means for supporting and guiding the elongate members takes the form of first and second frames spaced apart in the tunnel driving direction and one of the frames is provided with adjustable means for expanding or contracting the frame relative to the tunnel wall to thereby bring the elongate members into a position where their longitudinal axes all converge rearwardly of the tunnel driving direction.

Tunnel driving apparatus with a shield composed of a plurality of elongate members arranged in side-by-side relationship for contacting the wall of a tunnel, first and second frames spaced apart along the longitudinal central axis of the shield, the frames serving to support and guide the members for longitudinal displacement adjustable means for varying the effective size of one of the frames in relation to the other to bring all the axes of the elongate members into a parallel relationship or into a relationship where the said axes converge in a rearward direction relative to the direction of tunnel advancement, a bracing structure interconnecting the frames, said bracing structure being composed of struts connected between the frames in a diagonal manner to intersect at a central region between the frames, each strut being rigidly connected to one of the frames and articulated to the other of the frames and detachable locking means for rigidly interconnecting the struts to said other frame and to each other when desired.

Tunnel driving apparatus with a shield composed of a plurality of elongate members arranged side-by-side around a central longitudinal shield axis, frame means supporting and guiding all the members for individual longitudinal displacement in the tunnel driving direction and adjustment means acting on the frame means to displace all the elongate members over a rear zone symmetrically and simultaneously transversely of the shield axis whereby all the axes of the members can be brought into parallelism or into a relationship where their axes converge in a rearward direction relative to the tunnel driving direction.