Results 71 - 80 of 151

• Reinforcing Coal Mine Roof with Polyurethane Injection: 4 Case Studies
  10/1/2008 - Peer reviewed journal articles
  This paper gives the results of 4 case studies concerning the interaction between polyurethane (PUR) and coal mine roof in order to determine the mechanism of reinforcement, in both highly fractured rock and unfractured rock.
• Pillar Strength and Design Methodology for Stone Mines
  7/1/2008 - Conference papers
  This paper presents a pillar design methodology that was developed from a study of pillar performance in operating stone mines and concludes with guidelines for applying a developed equation and selecting appropriate input parameters.
• A First Step in Developing Roof Support Design Criteria Based on Ground Reaction Data for Pittsburgh Seam Longwall Tailgate Support
  7/1/2008 - Conference papers
  In this NIOSH study to optimize standing roof support design, ground response curves were developed for longwall tailgate conditions from numerical models of Pittsburgh Coal Seam geology.
• 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.
• 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 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.
• 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.