Abstract
SUMMARY This work aims at the detection of instabilities in underground mine roadway roof, with the goal of predicting and preventing roof failure and collapse. Openings in the rock have their own resonances, due to the propagation of seismic waves in the rock around the opening. If the surrounding rock is damaged or fractured, this would result in the resonant frequencies decreasing. An experiment was set up in an underground mine to detect these resonances and see how they change in the process of rock degradation leading up to collapse. Accelerometers were grouted into a mine roadway roof, along with displacement and stress sensors. Waveforms from mining-induced microseismic events were recorded. The spectra of the coda of these events were used to search for resonances. Strong resonance modes were indeed seen, which were stable over time. The resonance frequencies did decrease in the days prior to roof collapse, in parallel with measured stress changes. At the time when significant movement was detected in the roof rocks, the resonance modes changed completely, probably due to delamination of the rock causing seismic decoupling. This means that resonance modes could be used for roof stability monitoring.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
