PURPOSE: To improve the water seal performance and workability by arranging a high rigidity coupling metal fitting on the end surface in the circumferential direction of a segment for tunnel covering, embedding an insert having a hollow screw on the end surface of the other segment, and bolt-joinning both.
CONSTITUTION: An insert 15 having a hollow screw 16 is arranged on the end surface 6a in the circumferential direction of an already installed segment 6, and when a segment 6 which is newly joined with the end surface 6a in the circumferential direction of the already installed segment 6 is inserted toward a pit opening side from a coal pit side, a cone-shaped projection part 12 which projects from the end surface 6a of the segment 6 is fitted with one end part of a slot hole shaped groove 18 formed on the end surface 6a of the segment 6, and the projection part 12 is slided in the tunnel axis direction along the groove 18. Further, the segment 6 allows the projection part 12 to stop immediately before the insert 15, and a bolt hole formed on a high rigidity coupling metal fitting 1 and the hollow screw 16 are allowed to coincide, and screwed by the bolt. An O-ring 13 is fitted into a groove 14, and the segment 6 having the insert 15 formed in at least two stages is joined by a connecting member 17.
NAKAJIMA MAKOTO
FUJIKI IKUO
TASHIRO NOBORU
KAWACHI HIROTOMO
ABE SHIGEKI
HATADA MINORU
DAICHIYOU TADAHIRO
DOSONO YOSUKE
FUJINO YUTAKA
KUMAGAI GUMI CO LTD
NIPPON STEEL CORP
GEOSTR CORP