CONCRETE SEGMENT

PURPOSE: To secure the rigidity of a connecting part and prevent cracks and water leakage from occurring, by making partially thin a segment body along the curved face in the containing hole of a connection tool and making constant the thickness of the part of the containing hole. CONSTITUTION: Ring joints are provided at the thick faces of both sides of a segment body 1 and mutual rings from a plurality of pieces are connected to constitute a ring joint with a joint plate 3 and a containing hole 4. In this case, an injection hole is arranged at the center of body 1 and after connection of mutual rings mortar is injected from an injection opening to fill clearances between the rings and the ground and other clearances. And a ring is connected to another ring which has already assembled and arranged through ring-joint bolts, to form the lining thickness of a tunnel. The containing holes 4 for connection tool 5 are made along the curved face la with a distance of thickness Ll. In this way, the bending moment, axial force, and shearing force due to the earth pressure and hydraulic pressure acting on the connection part of the body 1 are prevented from concentrating on the thick parts and dispersed and hence, the rigidity is increased.