Driving tunnels with wedge forming appts - has roof beams with tapered front mounted on self advancing support

摘要

Equipment for driving tunnels by a wedge procedure in which the exposed roof of the unsupported front part of the tunnel is secured by beams with wedge shaped front ends. The beams which are positioned side by side are mounted between the tunnel face and a permanent tunnel support adjoining the exposed roof. The beams are tensioned against the exposed roof by self advancing support units consisting of a number of jointly controlled adjustable props and roof bars on which the beams are resting. The support units are alternatively moved relatively to each other in the direction of tunnel driving and the beams are advanced by hydraulic cylinders positioned against the permanent support of the tunnel.