Report of Investigations 9413: Effects of Horizontal Stress Related to Stream Valleys on the Stability of Coal Mine Openings

Details

• Journal Article:
  Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9413
• Personal Author:
  Molinda, Gregory M.
• Description:
  The U.S. Bureau of Mines conducted an investigation to determine the nature and frequency of coal mine roof failure beneath valleys. A mechanism for this failure and suggestions for controlling this problem are presented. Hazardous roof conditions identified in some mines were positively correlated with mining activities beneath stream valleys. Mine maps with overlays of unstable roof and locations of stream valleys show that 52 pct of the instances of all unstable roof in the surveyed mines occurred directly beneath the bottom-most part of the valley. The survey also showed that broad, flat-bottomed valleys were more likely to be sites of hazardous roof than narrow-bottomed valleys. Evidence of valley stress relief was found beneath several valleys in the form of bedding plane faults and low-angle thrust faults. This type of failure, previously believed to be only a shallow phenomenon, was found at mining depths as great as 300 ft. In situ, horizontal stress measurements beneath a valley and the adjacent hillsides confirmed valley stress relief. Numerical analysis of 13 valleys overlying 1 mine property showed the effect of the valley excavation on horizontal and vertical stress. [Description provided by NIOSH]
• Subjects:
  Coal Coal Mining Geology Mining Occupational Health Safety
• Keywords:
  Mining-industry; Coal-mining; Underground-mining; Geology; Ground-stability
• Source:
  Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9413, 1992 Jan; :1-26
• Series:
  NIOSH Numbered Publications   ; Mining Publications  
• Subseries:
  Report of Investigations
• Document Type:
  Text
• Genre:
  Report
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  PRC - Pittsburgh Research Center
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  32 pdf pages
• NIOSHTIC Number:
  nn:10011395
• Federal Fiscal Year:
  1992
• Peer Reviewed:
  False
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:ca80b334fb34262bba40acbf088f30aeb6906cf29b34b7ffe5656c76a4396f9e24ccb790e9f8b5490e412093ba80708eb14815bd1915472e00fa191a8f78f7b5
• Download URL:
  https://stacks.cdc.gov/view/cdc/10109/cdc_10109_DS1.pdf
• File Type:
  [PDF - 1.69 MB ]