Attitude control means of tunnel boring machine shield

摘要

An improved attitude control system for tunnel boring machine shields is provided. A laser beam transmitter is installed in an already bored tunnel behind the machine shield for transmitting a laser beam in parallel to a predetermined tunneling direction and a device for receiving the beam is installed in the shield for detecting any deviation of the shield from the beam so that, when the deviation is detected during tunneling work performed by rotating a foreward end cutter head of the shield and propelling the shield toward tunnel face ground with a plurality of jacks installed at rearward end of the shield, the jacks are selectively driven in response to resultant deviational direction and amount of the detection so as to remove the deviation.