Investigation of electromagnetic emissions in a deep underground mine.
Scott-DF; Williams-T; Knoll-S
2004 SME Annual Meeting, Feb 23-25, Denver, Colorado, Preprint 04-79. Littleton, CO: Society for Mining, Metallurgy, and Exploration, Inc., 2004 Feb; :1-7
Highly stressed rock in stopes continues to be a primary safety risk for miners in underground mines because it can result in failures of ground that lead to both injuries and death. Spokane Research Laboratory personnel investigated electromagnetic (EM) emissions in a deep underground mine in an effort to determine if these emissions could be used as indicators of impending catastrophic ground failure. Results suggest that (1) there is no increase in the number of EM emissions prior to recorded seismic activity, (2) some EM signals are generated during blasting, (3) interference from mine electrical sources mask seismic-generated EM signals, (4) EM emissions do not give enough warning (compared to seismic monitoring) to permit miners to leave a stope, (5) the distance an EM signal can travel in the rock is between 18 and 40 m, and (6) current data acquisition systems do not differentiate between EM signals generated from seismic activity and random mine electrical noise. These results preclude monitoring EM emissions as precursors of impending catastrophic ground failure.
Mining-industry; Underground-mining; Electromagnetic-energy; Electromagnetic-fields; Electromagnetic-radiation; Ground-stability; Rock-falls; Rock-mechanics; Accident-prevention; Injury-prevention
Research Tools and Approaches: Control Technology and Personal Protective Equipment
2004 SME Annual Meeting, Feb 23-25, Denver, Colorado, Preprint 04-79