SEGMENT FOR TUNNEL LINING

PROBLEM TO BE SOLVED: To connect segments in the axial direction of a tunnel speedily and simply. SOLUTION: A recessed groove part 6 having a predetermined width is formed along the direction of substantially circumference of a segment in a join face part crossing orthgonally for a tunnel axis, and a platelike hook joint 2 which protrudes and is fixed using a bottom of this recessed groove part 6 as a reference end is provided. This hook joint 2 has a locking pawl 2B having a predetermined width in a tip part thereof, an inclined face 2b is, formed on an outer face part of the locking pawl 2B, one set of biting hook joints 2, 2 are arranged in such a manner that the directions of respective locking pawls 2B, 2B are reverse mutually between segments joined in the axial direction of a tunnel, and respective hook joints 2, 2 bite automatically by deforming elastically to sides due to the contact of the inclined faces 2b, 2b formed in an outer face part at tips thereof in accordance with the travel of segment in the axial direction of the tunnel due to joining of segments 1.