Abstract

We studied the potential of a fiber-based sensor using the Tunable Wavelength Coherent Optical Time Domain Reflectometry (TW-COTDR) technique to monitor the distributed strain profile inside a tunnel shotcrete, with and without yieldable concrete wedges. Design of the measuring system and on-site test are reported. We demonstrated ability and performances of optical fiber sensing cable through several weeks monitoring in shotcrete. Results are shown to be comparable to those provided by the reference vibrating wire extensometers and distributed measurements will be of major interest for advanced understanding of performances and limitation of shotcrete mechanical behavior.

© 2016 Optical Society of America