광섬유를 이용한 철도터널 균열 검지

Crack is one of the key parameters to assess the stability of an operating tunnel. A new method to detect cracks in railway tunnel is proposed. Optical fibers are attached to the faces of tunnel lining and OTDR (Optical Time Domain Reflectometry) is used to detect their disconnections occurred by cracks. A crack generator was used to evaluate the detectabilty of three different optical fibers according to crack width in the laboratory. A case that the proposed method was applied to an operating railway tunnel is introduced.