Investigation of Pillar-Roof Contact Failure in Northern Appalachian Stone Mine Workings

Details

• Personal Author:
  Esterhuizen, Gabriel S. ; Iannacchione, Anthony T.
• Description:
  The roof rock in underground limestone mines in northern Appalachia can be subject to high horizontal stresses despite the shallow depth of the workings. The high stresses can cause roof stability problems. NIOSH researchers have observed a distinctive, asymmetrical mode of failure at the pillar-roof contact in two underground stone mines, which is different from the typical failure mode observed in response to excessive levels of horizontal stress. A dip of greater than 5 deg was identified as a possible cause of this mode of failure. Numerical model experiments showed that an increase in the dip of the workings can cause an increase in the stress at the up-dip corner of the roof beam. A case study is presented in which failure at the pillar-roof contact was observed where the dip of the workings was 7 deg in a high horizontal stress field. Numerical modeling showed that the relatively small dip of the workings could have induced stress changes in the immediate roof that would explain the failures. The model results also showed that this mode of failure is less likely to occur if the limestone pillars contain weak bedding planes that provide stress relief. In addition, the results showed that for the conditions at the case study site, the stress in the roof beam was not sensitive to the thickness of the roof beam or the excavation span. The high horizontal stresses at this site are an important contributing factor to the observed failures. [Description provided by NIOSH]
• Subjects:
  Mining Occupational Health Safety
• Keywords:
  Ground-control Models Safety-research Stone-mines Underground-mining
• Series:
  Mining Publications
• ISBN:
  0939084569
• Publisher:
  West Virginia University
• Document Type:
  Text
• Genre:
  Proceedings
• Place as Subject:
  OSHA Region 3 ; Pennsylvania ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  PRL - Pittsburgh Research Laboratory
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  320-326
• NIOSHTIC Number:
  nn:20025350
• Citation:
  Proceedings of the 23rd International Conference on Ground Control in Mining, August 3-5, 2004, Morgantown, West Virginia. Peng SS, Mark C, Finfinger GL, Tadolini SC, Heasley KA, Khair AW eds., Morgantown, WV: West Virginia University, 2004 Aug; :320-326
• Editor(s):
  Peng SS; Mark C; Finfinger GL; Tadolini SC; Heasley KA; Khair AW
• Federal Fiscal Year:
  2004
• NORA Priority Area:
  Disease and Injury: Traumatic Injuries
• Peer Reviewed:
  False
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:2305029a6ecc76befd5e48298fdbe8b01edfd11716b200b3d166abb6aba5b2e83415a0fbc28591efcfd98207939e1dd77fca5476b606eddcd19a0abb8a50c842
• Download URL:
  https://stacks.cdc.gov/view/cdc/220922/cdc_220922_DS1.pdf
• File Type:
  [PDF - 1.76 MB ]