TUNNEL WIDTH EXPANDING METHOD, SEGMENT AND SHIELDING MACHINE

摘要

PROBLEM TO BE SOLVED: To provide a tunnel width expanding method, a segment and a shielding machine for expanding a width of the segment without caring about water cut-off performance between a shielding machine tail part and the segment by independently expanding the width by the segment after the shielding machine passes. SOLUTION: A width expanding segment ring 21 having an outer diameter equal to a segment ring arranged in an ordinary pit 10 is assembled inside an overbreak part 17 of a width expanded pit 12 excavated by using a shield excavator 1 having a copy cutter 7. After an excavator body 3 passes through the width expanded pit 12, a jacking jack of the shield excavator 1 is separated from a segment 11 in front of the width expanded segment 15, and while maintaining a shape of a segment 23 of the width expanding segment ring 21, the width expended segment 15 is moved in the overbreak part 17. Temporary parts 43a and 43b of the width expanded segment 15 are removed, and width expanded parts 45a and 45b of a tunnel 8 are formed. COPYRIGHT: (C)2004,JPO