Automatic segment erection system for shield tunnels

Shield tunnelling is now the practice most frequently used in the tunnelling of urban areas. This paper discusses an automatic segment erection system developed for the unmanned implementation of the shield method. The system is composed of a segment erection robot and an automatic segment feeder; the former assembles segments which prevent the collapse of the rock mass and form a tunnel wall, and the latter supplies segments to the robot. It has been difficult to automate the erection steps because the segment pieces are very heavy. So, segment erection has been a problem in the development of an unmanned shield method. The robot reported here has overcome this difficulty, being able to position and join, with high accuracy, a segment in relation to segments already installed. This system was used in shield tunnelling on the largest scale yet seen in the world.