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Rating the Strength of Coal Mine Roof Rocks.

PB96155072

Publication Date	1996
Personal Author	Molinda, G. M.; Mark, C.
Page Count	43
Abstract	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.
Keywords	Coal mines Roofs Rock mechanics Ground control Structural analysis Strength of materials Anisotropy Physical properties Mechanical properties Compressive strength Moisture uptake Adsorption Load tests Roof bolts Photographs Rock strength Point loads
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries 50D - Soil & Rock Mechanics
Corporate Authors	Bureau of Mines, Pittsburgh, PA. Pittsburgh Research Center.
Document Type	Technical Report
Title Note	Information circular/1996.
NTIS Issue Number	199611

Rating the Strength of Coal Mine Roof Rocks.

Rating the Strength of Coal Mine Roof Rocks.
PB96155072

Publication Date	1996
Personal Author	Molinda, G. M.; Mark, C.
Page Count	43
Abstract	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.
Keywords	Coal mines Roofs Rock mechanics Ground control Structural analysis Strength of materials Anisotropy Physical properties Mechanical properties Compressive strength Moisture uptake Adsorption Load tests Roof bolts Photographs Rock strength Point loads
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries 50D - Soil & Rock Mechanics
Corporate Authors	Bureau of Mines, Pittsburgh, PA. Pittsburgh Research Center.
Document Type	Technical Report
Title Note	Information circular/1996.
NTIS Issue Number	199611