Results 1 - 10 of 11

• CMRR - Coal Mine Roof Rating
  8/20/2013 - PC software
  Software for estimating the relative inherent strength of coal mine roof.
• Development and Application of the Coal Mine Roof Rating (CMRR)
  5/1/2007 - Conference papers
  This paper discusses the sources used in developing the CMRR, describes the CMRR data collection and calculation procedures, and briefly presents a number of practical mining applications in which the CMRR has played a prominent role.
• Using the Coal Mine Roof Rating (CMRR) to Assess Roof Stability in U.S. Coal Mines
  8/1/2001 - Peer reviewed journal articles
  The CMRR quantifies defects in the rock mass and compiles a strength value used for engineering design. The CMRR has been applied to a number of ground stability problems. The CMRR procedure and some of these applications are described in this paper.
• Application of the Coal Mine Roof Rating (CMRR) to Extended Cuts
  4/1/1999 - Peer reviewed journal articles
  The Coal Mine Roof Rating (CMRR) has been widely accepted as a tool for geologic characterization and mine planning. The application of the CMRR to extended cuts (cuts greater that 6 m (20 ft) in length) is discussed.
• Technology News 517 - New Updates for NIOSH Coal Mine Ground Control Software
  4/1/2006 - Technology News
  Updates to the NIOSH suite of coal mine ground control software are described, including the Analysis of Roof Bolt Systems (ARBS), the Support Technology Optimization Program (STOP), and the Coal Mine Roof Rating (CMRR).
• Technology News 505 - NIOSH Releases New Coal Mine Roof Rating Software
  4/1/2003 - Technology News
  The Coal Mine Roof Rating (CMRR) is a roof classification system. It was first introduced to the mining community in 1994. It has now been written to a user friendly version that can be run on any PC with a Windows operating system.
• New Developments with the Coal Mine Roof Rating
  8/1/2002 - Conference papers
  The purpose of this paper is to bring the mining community up to date with recent improvements and applications of the CMRR.
• Using the Point Load Test to Determine the Uniaxial Compressive Strength of Coal Measure Rock
  8/1/2000 - Conference papers
  This study involved extensive load frame and point load testing of coal measure rocks in six states. More than 10,000 test results from 908 distinct rock units were used to classify rock lithologies into categories and determine conversion factors.
• Comparison of Ground Conditions and Ground Control Practices in the United States and Australia
  8/1/1998 - Conference papers
  Ground conditions at 10 Australian longwall mines and two room-and-pillar mines are compared with an extensive database from U.S. mines. Comparisons include the Coal Mine Roof Rating, roof support, pillar design, and ground control conditions.
• Factors Influencing Intersection Stability in U.S. Coal Mines
  8/1/1998 - Conference papers
  Based on field investigations and a U.S. coal mines database containing 12 mines and 639 roof falls, NIOSH determines the factors that influence intersection instability and provides guidelines for the safe excavation and support of intersections.