Results 61 - 70 of 128

• Field Observations and Numerical Studies of Horizontal Stress Effects on Roof Stability in U.S. Limestone Mines
  6/1/2008 - Peer reviewed journal articles
  This paper describes a modeling approach that can be used as a tool to evaluate potential roof failure and optimize the stability of room and pillar layouts.
• Three-Dimensional Time-Lapse Velocity Tomography of an Underground Longwall Panel
  6/1/2008 - Peer reviewed journal articles
  This paper describes the 3D velocity tomograms that were generated to image the stress redistribution around an underground coal longwall panel to produce a better understanding of the mechanisms that lead to ground failure, especially rockbursts.
• A Case Study Examination of Two Blast Rounds at a Nevada Gold Mine
  1/1/2008 - Conference papers
  NIOSH researchers collected basic data from two blast rounds at the SSX-Steer Mine as a component of a larger study on controlled blasting, the goal of which is to reduce injuries from falling rocks in underground mines.
• Methods for Determining Roof Fall Risk in Underground Mines
  11/1/2007 - Peer reviewed journal articles
  This paper discusses a method to determine the roof fall risk using a qualitative risk analysis technique.
• Time-Lapse Tomography of a Longwall Panel: A Comparison of Location Schemes
  7/1/2007 - Conference papers
  This paper describes a project in which three-dimensional time-lapse velocity tomograms were generated to image stress redistribution around a longwall panel to produce a better understanding of the mechanisms that lead to ground failure.
• Multiple-Seam Mining Interactions: Case Histories from the Harris No. 1 Mine
  5/1/2007 - Conference papers, Information Circulars
  A detailed evaluation of the multiple-seam experiences at Harris No. 1 Mine was done as part of NIOSH's nationwide multiple-seam mining case history database.
• Proceedings: New Technology for Ground Control in Multiple-seam Mining
  5/1/2007 - Information Circulars, NIOSH/USBM numbered publications
  Multiple-seam interactions are a major ground control hazard in many U.S. underground coal mines. NIOSH has been conducting research to develop better techniques for predicting the location and severity of multiple-seam interactions.
• Multiple-Seam Mining in the United States: Background
  5/1/2007 - Information Circulars
  For the past several years, NIOSH has been conducting research to develop better techniques for predicting the location and severity of multiple-seam interactions. This paper presents the background to that study.
• An Evaluation of Microseismic Activity Associated with Major Roof Falls in a Limestone Mine: a Case Study
  2/1/2007 - Conference papers
  The goal of this study was to review periods of elevated microseismic activity and determine whether fracture activity rate can be used to anticipate roof falls. The results showed that limited success would be achieved by such a system.
• Technique to Assess Hazards in Underground Stone Mines: the Roof Fall Risk Index (RFRI)
  1/1/2007 - Peer reviewed journal articles
  A roof-fall hazard-assessment technique was developed based on engineering judgment acquired from extensive underground stone mine experience and on examination of the literature. The technique uses observational processes to assess roof fall hazard.