Volt/bolt box breech mechanism and closed tool Inlaying business crevice cutting device null of segment for shield tunnel construction method

摘要

PROBLEM TO BE SOLVED: To allow any worker to simply cut an inner side of a bolt box and to cope with even a case of different dimensions of the bolt boxes and to close the bolt box merely by pushing a closing device into the bolt box so as to simplify the work. SOLUTION: A recessed part is provided on an inner wall of a bolt box 8 of a segment 4, and a projecting part provided on a closing device 10 having the same size and shape as the bolt box 8 is fitted in this recessed part to close the bolt box 8. Moreover, the recessed part is cut by a cutting device having a support base supported by the bolt box 8 and a cutting blade slidable relatively for the support base.