This study is a feasibility test to evaluate the use of Fibre Optics Sensing as a potential solution for ground vibration monitoring during underground excavation with respect to practical applications in mining activities including prediction of biotite containing volumes ahead of the tunnel face. The Distributed Acoustic Sensing technology has high potential also for other purposes, e.g., for infrastructure tunnel works. The quality of Fibre Optics Sensing data as compared to other types of traditional seismic acquisitions is investigated, as well as the operational benefits and constraints for the use of this technology during rock characterization.
Several hundreds of meters of fibre optical cables have been installed between two mine drifts, shotcreting the cables along the rock wall. The measurements on those cables have been performed in two different monitoring experiments in 2022 and 2024. Two different types of cables have been tested: a regular telecommunication cable and a more robust armoured cable. Thus, the sensing performance of the two cables is analogous, the armoured cable survived a local displacement due to an evident crack in the wall.
The project has been financed by BeFo with co-funding and in-kind from Lunds university, LTH, LKAB, RISE and the University of Cagliari (Italy). The reference group consisted of Fredrik Kullander, Björn Lund, Mats Svensson, Jennifer Juslenius, Fredrik Nylén, Per Tengborg, and Patrik Vidstrand.
Stockholm
Patrik Vidstrand
