The segment shape retaining device in shield tunnel

摘要

PROBLEM TO BE SOLVED: To provide a segment shape retention device for a shield tunnel, which can retain a segment shape in a wide range and which enables stable forward movement of a shape retention jack.SOLUTION: A segment shape retention device 3 is provided between a shield machine 1 and a floor slab 2. The segment shape retention device 3 includes preceding and following shape retention jack groups 6 and 7. When preceding shape retention jacks 61 to 65 of the preceding shape retention jack group 6 are expanded for retention of a segment shape in the forward movement of the shield machine 1, following shape retention jacks 71 to 75 of the following shape retention jack group 7 are contracted to release the retention of the segment shape, and the following shape retention jack group 7 moves forward.