Results 41 - 50 of 73

• The Effects of Water Spray Placement for Controlling Respirable Dust and Face Methane Concentrations
  4/1/2006 - Peer reviewed journal articles
  A series of laboratory evaluations examined the impact of water spray pressure, curtain setback distance, and external and underboom spray use for controlling respirable dust levels and sulfur hexafluoride tracer gas concentrations around a continuous m...
• Multiple Seam Mining Interactions: Case Histories from the Harris No. 1 Mine
  8/1/2005 - Conference papers
  Results show that the remnant upper seam structure's size can influence multiple seam interaction. Specifically, smaller critically loaded upper seam pillars appear more likely to cause lower seam ground control problems than wider pillars.
• 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.
• Use of a Directional Spray System Design to Control Respirable Dust and Face Gas Concentrations Around a Continuous Mining Machine
  12/1/2004 - Peer reviewed journal articles
  A laboratory study assessed the impacts of water spray pressure, face ventilation quantity, and line brattice setback distance on respirable dust and SF6 tracer gas concentrations around a continuous mining machine using a sprayfan or directional spray ...
• Evaluation of Polyurethane Injection for Beltway Roof Stabilization in a West Virginia Coal Mine
  8/1/2004 - Conference papers
  Polyurethane injection is a proven method of rock stabilization in even the weakest, most broken ground. Optimization of the injection design by pre-injection video diagnostics can greatly contribute to successful and efficient roof stabilization.
• Ventilation Planning Layouts for Large Opening Mines
  2/1/2004 - Conference papers
  Describes three alternative ventilation models for use in large opening underground mines with respect to their use in mines of various levels of development.
• Deep Cover Pillar Extraction in the U.S. Coalfields
  8/1/2002 - Conference papers
  A study is described with the objective of evaluating the various methods and strategies by which panels, production pillars and barrier pillars are developed and extracted under deep cover, and to develop appropriate design guidelines.
• Evaluation of Pillar Recovery in Southern West Virginia
  8/1/2002 - Conference papers
  Studies have identified a number of factors for evaluating a pillar extraction plan. This paper discusses each of the factors, presents relevant accident statistics, and shows how the risk factors can be combined to estimate the overall hazard.
• Sizing of Final Stumps for Safer Pillar Extraction
  8/1/2001 - Conference papers
  The risk of major pillar falls can often be reduced by leaving final stumps, large enough to protect the intersection but small enough to not inhibit gob caving. Analyses were conducted to assess factors on the size variation of remnant stumps.
• Effects of Bolt Spacing, Bolt Length, and Roof Span on Bolt Loading in a Trona Mine
  8/1/2001 - Conference papers
  NIOSH researchers installed 39 instrumented, fully grouted bolts at six test sites in a trona mine retreat panel to study mine roof stability for the improvement of workplace safety.