Results 121 - 130 of 224

• Empirical Design of Span Openings in Weak Rock based upon Support Type Employed
  6/1/2008 - Conference papers
  This work attempts to provide rock mechanic tools that will enable a mine operator to make economic decisions that will also ensure a safe working environment.
• Rock Mass Behavior and Support Response in a Longwall Panel Pre-Driven Recovery Room
  3/1/2008 - Conference papers
  Some surprising results were revealed in this study designed and implemented by NIOSH to evaluate the effectiveness of pre-driven longwall recovery rooms supported with pumpable concrete roof supports.
• Technology News 529 - New Technology for Ground Control in Multiple-Seam Mining
  11/1/2007 - Technology News
  Research by NIOSH on multiple-seam mining has resulted in two ground control products. The first is IC 9495 which is a proceedings document. The second is the Analysis of Multiple-Seam Stability software package. Each product is briefly described.
• Improving the Capability for Real Time Assessment of Roof Conditions Through Intelligent Roof Bolt Drilling Operations
  7/1/2007 - Conference papers
  An intelligent drilling system has been developed that can complement scoping and core analysis to provide a more complete picture of roof strata and is capable of seeing features or conditions that are not always obvious in more traditional methods.
• The Unpredictable Life Cycle of a Coal Pillar
  7/1/2007 - Conference papers
  A unique circumstance created by monitoring a pre-driven longwall recovery room permitted measuring the stresses of a coal pillar throughout its entire life cycle in less than a week. The complete transformation took place in less than 12 hours.
• Roof Screening for Underground Coal Mines: Recent Developments
  7/1/2007 - Conference papers
  This paper describes some successful techniques and machine modifications that were evaluated for ergonomic considerations and are being used in productive mines to assist with roof screen installation.
• Roof Stability Issues in Underground Limestone Mines in the United States
  7/1/2007 - Conference papers
  This paper presents the results of a study of roof conditions in 34 limestone mines in the Eastern and Midwestern U.S.
• Longwall Shield and Standing Gateroad Support Designs - Is Bigger Better?
  6/1/2007 - Conference papers
  There are fundamental aspects of support design and ground control that we still do not understand or recognize when designing a support system. These issues are evaluated and a different approach to support design is proposed.
• 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.
• Observations and Evaluation of Floor Benching Effects on Pillar Stability in U.S. Limestone Mines
  5/1/2007 - Conference papers
  A survey of roof and pillar conditions in limestone mines has revealed that bench mining of the floor between pillars can cause instability in the pillars at the perimeter of the benched area. Numerical models were used to assess those effects.