FLEXIBLE SEALING MATERIAL AND JOINT STRUCTURE FOR SHIELD TUNNEL USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a flexible sealing material which does not form grooves or conspicuous projections on the periphery of a segment ring but forms an almost smooth peripheral surface on the periphery when subjected to compressive deformation by jack thrust, and to provide a joint structure for a shield tunnel using the flexible sealing material. SOLUTION: The flexible sealing material 10 includes a sealing material main body 11 which is retained between at least a pair of the segment rings and subjected to compressive deformation. With respect to a cross section of the flexible sealing material 10, (i) the tip 11a of the sealing material main body 11 includes a recessed portion 11b at its center, and a ratio D/W between a width W of the sealing material main body 11 and a depth D of the recessed portion is set to 0.1 or less when the flexible sealing material 10 is not in a compressed state. Alternatively, (ii) the tip 11a of the sealing material main body 11 is flat.