Abstract: Structural members 1, 21 are connected by way of a connecting rod 3 which is attached to one structural member 1 and projects outward from connecting surface 2 of structural member 1 in the direction of other structural member 21, and a connector 23 which is attached to other structural member 21 and has a plurality of wedges 25 which engage with connecting rod 3 stopping it so that it cannot slip out. Connecting rod 3 is attached so as to be moveable in a direction parallel to connecting surface 2.

Abstract: One end of a circumferential joining end surface 2 of segments 1 which are joined together in the circumferential direction of an excavated tunnel is made the male side circumferential joining end surface 2a on which a male coupler 4 is provided, and the other end is made a female side circumferential joining end surface 2b on which a female coupler 5 is provided. On a base plate 7, a bolt 10, which provides an engagement part 16 comprising a flat washer 13, a disc spring 14, and a head 15, is erected, and made a male coupler 4. An engagement plate 23, formed by a notch 22 which engages the bolt 10, and is inserted and engaged between the base plate 7 and the engagement part 16, and tightly held by the elastic force of the disc springs 14, is made the female coupler 5.