PURPOSE:  Reduce hazards from rock mass instabilities in the underground mining workplace through (1) hazard mitigation studies that make use of seismic monitoring tools and (2) knowledge and technology transfer to industry.

RESEARCH SUMMARY:  Rock bursts, coal bumps, and other large-scale dynamic failures represent serious ground control problems facing miners in certain industry sectors. These low-probability/high-consequence events often result in severe injuries or death and have the potential to affect an entire underground workforce. An inability to address these problems effectively can result in resource abandonment and/or mine closure and a significant economic impact on entire communities.

Research personnel engage in joint projects with the mining industry using seismic monitoring tools to advance worker safety through several different avenues. These include (1) providing worker awareness of unusual ground response to mining, (2) forensic analyses of catastrophic failures, (3) guidance in rescue efforts, and (4) evaluation of hazard mitigation measures.

Several types of seismic monitoring systems have been developed and/or adapted for these different applications. They range from simple, low-cost, single-sensor seismic stations to sophisticated, multi-channel, wireless computer-network-based distributed data collection, processing, analysis, and display systems. Current project work involves a combination of technology transfer activities and ground control research. Project personnel are helping one western Colorado coal mine operator develop its own full-scale seismic monitoring network based on NIOSH’s wireless methods. The network will monitor seismicity in the vicinity of mine workings adjacent to an earthen dam and reservoir and will cover an area of approximately 50 square kilometers (20 sq. mi.). A temporary network will also be installed at a second Colorado coal mine in response to a request for assistance in characterizing mine-related seismic hazards at that property.

Data collected with these networks will be used to address the following research questions: (1) What are the failure mechanisms of damaging coal bumps and where do they originate? and (2) how close can mining approach a body of water and still avoid the hazards associated with dynamic rock mass failures?