Information Circular 9387: Coal Mine Roof Rating (CMRR): A Practical Rock Mass Classification for Coal Mines

Details

• Personal Author:
  Mark, Christopher ; Molinda, Gregory M.
• Description:
  The Coal Mine Roof Rating (CMRR) was developed by the U.S. Bureau of Mines as an engineering tool to quantify descriptive geologic information for use in coal mine design and roof support selection. The CMRR system combines the results of many years of geologic ground control research with worldwide experience with rock mass classification systems. Like other classification systems, the CMRR begins with the premise that the structural competence of mine roof rock is determined primarily by the discontinuities that weaken the rock fabric. The CMRR makes four unique contributions: (1) it is specifically designed for bedded coal measure rocks, (2) it concentrates on the bolted interval and its ability to form a stable mine structure, (3) it is applicable to all U.S. coal seams, and (4) it provides a methodology for data collection. Using only simple field tests and observations, the CMRR can be calculated from roof falls, overcasts, and highwall exposures. [Description provided by NIOSH]
• Subjects:
  Coal Coal Mining Mining Occupational Health Risk Assessment Safety
• Keywords:
  Coal-mines Cohesion Field-tests Flow-charts Geological-maps Geological-surveys Hazards Lithology Moisture Ratings Risk-analysis Roofs Sensitivity Shear-strength Spacing Structural-analysis Weight-mass

  More +
• Series:
  Mining Publications
• Subseries:
  Information Circular
• Document Type:
  Text
• Genre:
  Report
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  PRC - Pittsburgh Research Center
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  90 pdf pages
• NIOSHTIC Number:
  nn:10012317
• NTIS Accession Number:
  PB94-160041
• Citation:
  Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, IC 9387, 1994 Jan; :1-83
• Federal Fiscal Year:
  1994
• Peer Reviewed:
  False
• Source Full Name:
  Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, IC 9387
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:0cfe6155b3d3e446ffcd3ca5115a3e66005c87638075d9a3adb60d07f93e0b5c290d281aeb9aa10461809ae6985757fe84e829ae17d8e7cdb99015ded4b6c63a
• Download URL:
  https://stacks.cdc.gov/view/cdc/206327/cdc_206327_DS1.pdf
• File Type:
  [PDF - 3.96 MB ]