Application of Brillouin Optical Time Domain Reflection Technology for Monitoring Deformation and Failure of the Coal Seam Floor Rock Mass in Deep Underground MinesAplicación de la tecnología de reflexión óptica de Brillouin en el dominio del tiempo para supervisar la deformación y la falla del piso del macizo rocoso de la veta de carbón en minas subterráneas profundasAnwendung der optischen Brillouin-Zeitbereichsreflektometrie zur Überwachung der Verformung und des Versagens der Kohleflözsohle in tiefen Bergwerken

Almost all of the coalfields in East China are now mining deep seams. Accurate prediction of the damage to floor rock during mining is key to preventing and controlling coal seam floor water hazards in these deep mines. In this study, Brillouin optical time domain reflectometry (BODTR) was used to dynamically monitor the mining failure of a deep coal seam mine floor. A metal kieso sensing optical cable employing distributed optical fiber sensing technology was embedded in the coal seam floor prior to mining, which allowed real-time monitoring during mining. The strain data monitored using the BOTDR system and the strain threshold of the limit compression and tensile fracturing of the corresponding strata were compared and analyzed to obtain the accurate maximum failure depth of the coal seam floor strata. This approach improved the accuracy of the failure depth of the mine floor by 7–10% compared with traditional monitoring methods.