Development of EDZ Evaluation Technique for Underground Cavern Excavation by Distributed Fiber Optic Sensing Method

抄録

Excavation damaged zones are created when excavating underground caverns and generate AE at micro-amplitude. This research is a challenge to apply DAS with C-OTDR technology to AE measurement. The results of laboratory and in-situ experiments showed that differences in optical fiber specifications did not have a significant effect on AE measurements. In addition, it was found that source location can be identified in the same way as with conventional in-situ AE measurements. Furthermore, the monitoring range of conventional AE sensors is generally 5 m to 10 m, but the new method can extend the monitoring range to 35 m.