Room-and-pillar mining in bump-prone conditions and thin pillar mining as a bump mitigation technique

Details

• Personal Author:
  Barton, Timothy M. ; Compton, Craig S. ; Mucho, Thomas P.
• Corporate Authors:
  United States. Bureau of Mines
• Description:
  Retreat or pillar recovery mining redistributes the overburden weight onto the adjacent coal pillars in a room-and-pillar section. The additional stress and the resultant energy stored in the remaining pillars can become so great that pillars may bump or violently fail. An investigation at the Gary No.2 Mine was conducted to examine the effectiveness of the thin pillar mining method for mitigating bump occurrences. Field observations were made and instruments were installed to monitor pillar behavior during extraction. Stress monitoring instruments and roof-to-floor convergence stations were installed in pillars and entries and crosscuts, respectively. Results indicated that high pillar stress concentrations occurred in these bump-prone geologic conditions. The thin pillar mechanism, the creation and progressive outby movement of an expanded yield zone, was also monitored through the instruments. The expanded yield zone, a result of using thin pillars in a highly stressed pillar line area, mitigates bump risk.
  
  NIOSHTIC no. 10004550
  
  
• Subjects:
  Occupational Health Safety
• Series:
  Mining Publications
• Subseries:
  Report of Investigations
• Document Type:
  Text
• Genre:
  Report
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  18 pages
• NIOSHTIC Number:
  nn:10004550
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:85a215e79021737eb04e7b9e3ee3147253501f2a39bf8030a71cd5c57999ee88e81eb5a273943dfa8b299b5e2732d9c4c88bc5c7b21215e25b5d3f7416a95d1e
• Download URL:
  https://stacks.cdc.gov/view/cdc/10236/cdc_10236_DS1.pdf
• File Type:
  [PDF - 1.49 MB ]