Distributed fibre-optic technology for security monitoring of a structural load of road and motorway tunnels

The article is focused on the analysis of the use of the distributed fiber optic technology for security monitoring of a structural load of road and motorway tunnels. Brillouin Time Domain Reflectometry (BOTDR) was used to monitor the deformation. The principle is based on the measurement of the stimulated Brillouin scattering. The whole experiment was carried out during the construction of the motorway tunnel in Slovakia. As part of the construction of the tunnel, the standard optical telecommunication fiber was attached to the primary tunnel beams that was subsequently used as a sensor for the BOTDR system. The sensor allows monitoring and analysis of the load on the highway tunnel to ensure the safety of the structural load. In total, there were 6 measurement days, which were scheduled in 5 months of tunnel construction.