Results 181 - 189 of 189

• A Case Study of Bolt Performance in a Two-entry Gate Road
  8/1/1998 - Conference papers
  This paper presents the results of a case study conducted in a two-entry gateroad in a coal mine where excessive roof deformation and bolt loading resulted in failure of many roof supports.
• Roof and Rib Hazard Assessment for Underground Stone Mines
  1/1/1998 - Peer reviewed journal articles
  Roof and rib conditions were observed and assessed in 33 underground stone mines. It was found that selection of the mining horizon and mine layout decisions tremendously influence ground stability.
• International Experience with Longwall Mining into Pre-Driven Rooms
  1/1/1998 - Conference papers
  Unusual circumstances sometimes require a longwall retreat into/through a previously driven room, with the potential for failures and roof fall hazards. To determine the failure factors, NIOSH compiled an international database of 130 case histories.
• Technology News 467 - Wood Crib Performance Model
  11/1/1997 - Technology News
  With the increasing cost of wood and greater dependency on wood cribs for support in applications such as longwall tailgate and bleeder entries, more efficient use of wood crib supports is required.
• A Method for the Selection of Rock Support Based on Bolt Loading Measurements
  8/1/1997 - Conference papers
  A method to assist in the evaluation and selection of roof bolts using in situ measurements of roof bolt loading has been developed by researchers of the Spokane Research Center, National Institute for Occupational Safety and Health.
• Proceedings: Mechanics and Mitigation of Violent Failure in Coal and Hard-Rock Mines
  5/1/1995 - NIOSH/USBM numbered publications
  Papers presented at a USBM technology transfer seminar describe the causes of violent material failure in U.S. mines, measurement techniques for monitoring events that result in violent failure, and mitigation techniques for controlling failure.
• Stability Analysis of a Backfilled Room-and-Pillar Mine
  1/1/1995 - Reports of Investigations
  Displacement and stress changes in cemented backfill and ore pillars at the Buick Mine, near Boss, MO, were monitored by engineers from the U.S. Bureau of Mines and The Doe Run Co., St Louis, MO. Objectives of this research were to evaluate the effect ...
• Coal Mine Bumps: Five Case Studies in the Eastern United States
  1/1/1987 - Information Circulars
  Information was collected at 5 bump-prone mines. Among the findings, two geologic conditions have been found to cause bumps in the eastern U.S.: relatively thick overburden and extremely rigid strata immediately above and below the mine coalbed.
• Determining Cleat Orientation of Deeper Coalbeds From Overlying Coals
  1/1/1976 - Reports of Investigations
  Examination of several coalbeds in Walker County, Alabama, Cambria, Greene, and Fayette Counties, Pennsylvania, and Caleigh and Wyoming Counties, West Virginia, indicates that cleat orientations are similar throughout a vertical sequence of strata. Stud...