Telecommunications tunnel monitoring system based on distributed optical fiber strain measurement

摘要

We have developed a system for monitoring telecommunications tunnels to improve the reliability of telecommunication and to reduce maintenance costs through early damage detection. Core components of the system are a Brillouin optical time-domain reflectometer (BOTDR), which allows distributed and long-distance strain measurement, and optical fiber sensors installed in tunnels. Experimental results show that this system can detect tunnel deformation with a measurement error of 0.1 mm from a contraction of 1 mm to an elongation of 6 mm over a span of 10 km. The system used in practice at present is introduced.