Results 71 - 80 of 112

• NIOSH Computer Programs for Bench Crest Failure Analysis in Fractured Rock
  3/1/2005 - Conference papers
  A package of bench design programs is being publicly released by the National Institute for Occupational Safety and Health (NIOSH). These programs are designed to provide a probabilistic estimate of the likelihood that various widths of catch bench will...
• Empirical Approaches for Opening Design in Weak Rock Masses
  3/1/2005 - Peer reviewed journal articles
  A major focus of ground control research presently being conducted by the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) is to incorporate weak rock masses (such as are associated with operations in the ...
• Tests of Fibre-Reinforced Shotcrete at the Chief Joseph Mine, Butte, Montana
  2/1/2005 - Conference papers
  Researchers conducted tests to evaluate the tensile strength, fiber count, and adhesion of shotcrete applied to panels at the Chief Joseph Mine, a research and training facility operated by Montana Tech.
• Standing Support Alternatives in Western Longwalls
  2/1/2005 - Conference papers
  Western mines have had limited choices for standing support. This paper compares the performance characteristics of various support systems.
• Design in Weak Rock Masses: Nevada Underground Mining Operations
  2/1/2005 - Conference papers
  One focus of ground control research at NIOSH is to incorporate data on weak rock masses into existing design relationships, with an emphasis on updating the span design curve for manned entries and the overbreak curve for longhole entries. Both curves ...
• Effect of the Dip and Excavation Orientation on Roof Stability in Moderately Dipping Stone Mine Workings
  1/1/2005 - Conference papers
  In some underground limestone mines, the dip may exceed 5°. This can cause roof instability, which can be exacerbated by horizontal tectonic stresses. Field studies and numerical model analyses assess the effect of dip in various stress conditions.
• Preventing Falls of Ground in Coal Mines With Exceptionally Low-Strength Roof: Two Case Studies
  8/1/2004 - Conference papers
  Mines with low-strength roof are much more likely to struggle with roof falls. This paper focuses on two mines in two different seams, conducting statistical analysis to determine which support combinations have proven to be most effective.
• Numerical Modeling for Increased Understanding of the Behavior and Performance of Coal Mine Stoppings
  8/1/2004 - Conference papers
  In underground coal mines, concrete block stoppings are widely used to control mine ventilation. Researchers developed a numerical model to evaluate the performance of stopping materials and different wall geometries in a controlled environment.
• Hydraulic Prestressing Units: An Innovation in Roof Support Technology
  8/1/2004 - Conference papers
  A new generation of hydraulic mine support prestressing devices has been developed. This paper examines the performance capabilities of these inflatable prestressing units and the impact they have on the performance of various support systems.
• Investigation of Pillar-Roof Contact Failure in Northern Appalachian Stone Mine Workings
  8/1/2004 - Conference papers
  Underground limestone mine roofs in Northern Appalachia can be subject to high horizontal stresses. A case study is presented showing that induced stress changes in the immediate roof are less likely if the pillars contain weak bedding planes.