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Rating the strength of coal mine roof rocks.
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, IC 9444, 1996 Jan; :1-43
The Ferm pictoral classification of coal measure rocks is widely utilized in coalfield exploration. Although extremely useful as an alternative to conventional geologic description, no material properties are provided that would be suitable for engineering solutions. To remedy this problem, the USBM has tested over 30 common coal measure roof rock types for axial and bedding strength. More than 1,300 individual point load tests have been conducted on core from 8 different coal mines representing the full range of common coal measure rocks. The USBM core and roof exposure properties database has been merged with the picture classification to provide, for the first time, a simple, clear guide from field identification of core to the associated mechanical strength of the rock. For 33 of the most common roof rocks, the axial and diametral point load strength, as well as the ultimate unit rating, is overprinted onto the photograph.
Coal-mining; Equipment-design; Machine-operation; Measurement-equipment; Mining-industry; Standards; Underground-mining; Rock-mechanics; Ground-control; Structural-analysis; Strength-of-materials; Anisotropy; Physical-properties; Mechanical-properties; Compressive-strength; Moisture-uptake; Adsorption; Load-tests; Roof-bolts; Photographs; Coal-mines; Roofs
NTIS Accession No.
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, IC 9444
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division