| 摘要 |
PROBLEM TO BE SOLVED: To efficiently detect the deformation and crack of a tunnel by fixing an optical fiber at a specific interval so that it is extended in a circumferential direction at each concrete placement unit of lining for composing the tunnel. SOLUTION: First, an optical fiber distortion sensor 1 is inserted into a groove 10 for laying. Then, an adhesive 4 is injected and filled into a groove 10 and the inner wall surface of an adjacent lining 3 and a fixing tool 8 is mounted for adhesion and fixing so that the optical fiber distortion sensor 1 can be pressed. After that, the adhesive 4 is applied to the inner wall surface of the lining around the groove 10 at a central position between each of the fixing tools 8 along the groove 10 and a cover 9 is glued and fixed, thus loosely supplying the optical fiber distortion sensor 1 in the groove 10 and preventing it from departing from the groove 10 so that it can be expanded and contacted freely at the position of the cover 9, thus preventing the optical fiber distortion sensor 1 from projecting from the inner wall surface of the lining 3 and from being exposed to the wind pressure of a traveling body for releasing. |
