Mining Publication: Preventing Injuries Caused by Unrecognized Stone Mine Roof Beam Failures With a Pro-Active Roof Control Plan
Original creation date: March 1999
Unrecognized roof beam failures resulted in 69% of the falls of ground injuries occurring in underground U.S. stone mines from 1990 to 1996. Field investigations at 45 underground stone mines suggest that excessive beam sag or deflection is the principal unstable roof behavior characteristics associated with miner injuries. Laminated roof structures, common in most underground stone mines, allow the immediate roof to separate into distinct beams. The timely determination of roof beam deflection could provide stone miners with advanced know ledge of potentially hazardous roof. Existing methods to assess roof conditions consist of observational and monitoring techniques. Observational techniques include open drillholes, sounding, wedging, and borescopes. Monitoring techniques include scratch tools, extensometers, telltales, Miners Helpers, and Guardian Angels. Miners have difficulty utilizing these techniques because roof beams are located an average of 8 m (26.5 ft) above the miner's head in environments that are dark, dusty and noisy and these deflections are measured in millimeters of movement. To help mitigate the potential for falls of ground injuries to underground stone miners, the National Institute for Occupational Safety and Health (NIOSH) has developed the Roof Monitoring Safety System (RMSS) to aid in monitoring dangerous levels of roof beam deflection. If enough site-specific information is collected and placed on highly visible maps, individual mining operations could establish general guidelines for responding to specific roof beam deflection occurrences. This would help in implementing a pro-active, comprehensive roof control plan for reducing falls of ground injuries.
Authors: AT Iannacchione, LJ Prosser, RH Grau, DC Oyler, DR Dolinar, TE Marshall, CS Compton
Conference Paper - March 1999
NIOSHTIC2 Number: 20027590
1999 SME Annual Meeting, March 1-3, 1999, Denver, Colorado, preprint 99-87. Littleton, CO: Society for Mining, Metallurgy, and Exploration, 1999 Mar; :1-10
See Also
- Assessing Roof Fall Hazards for Underground Stone Mines: A Proposed Methodology
- Diagnosing and Controlling Moisture-Sensitive Roof in Coal Mines
- The Introduction of Roof Bolting to U.S. Underground Coal Mines (1948-1960): A Cautionary Tale
- Mistakes, Misconceptions, and Key Points Regarding Secondary Roof Support Systems
- Optimizing Secondary Roof Support with the NIOSH Support Technology Optimization Program (STOP)
- Performance Characteristics for Welded Wire Screen Used for Surface Control in Underground Coal Mines
- Roof and Rib Hazard Assessment for Underground Stone Mines
- Roof Span Design for Underground Stone Mines
- Technique to Assess Hazards in Underground Stone Mines: the Roof Fall Risk Index (RFRI)
- Technology News 520 - A Method to Characterize Risk Associated With Mine Roof Conditions
- Page last reviewed: 9/21/2012
- Page last updated: 9/21/2012
- Content source: National Institute for Occupational Safety and Health, Mining Program