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Critique of Pillar Design Equations from 1833 to 1990.

PB95105482

Publication Date	1994
Personal Author	Babcock, C.
Page Count	116
Abstract	When a flat-lying mineral deposit such as a coal seam is mined, some coal is left to separate the roof and floor so that miners and machines can safely mine the seam. The mineral left is in the form of mine pillars. If too much is taken, support problems and unsafe working conditions result. If too little is taken, the mining operation will be unable to compete economically with other mines. Therefore, one must select pillars of the optimal size to maximize mining recovery and minimize risk to miners and equipment. Later, if the pillar support is no longer needed and the surface can be allowed to subside the thickness of the coal seam, then the pillar support can be removed to increase mining recovery, and initial pillar size is not as critical. Only a small part of the information available on pillar design can be presented here. The purpose of this report is to summarize some of the work done by the U.S. Bureau of Mines and others on pillar design, which is reported in the literature from 1833 to the present, and present rock mechanics test results that aid in understanding mine pillar behavior. The variable names used are those of the authors cited. This results in multiple use of some variable names.
Keywords	Coal mining Underground mining Columns(Supports) Mining engineering Structural analysis Coal deposits Stress analysis Mathematical models Compressive strength Pillars
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries
Corporate Authors	Bureau of Mines, Denver, CO. Denver Research Center.
Supplemental Notes	Library of Congress catalog card no. 93-19066.
Document Type	Technical Report
Title Note	Information circular/1994.
NTIS Issue Number	199501

Critique of Pillar Design Equations from 1833 to 1990.

Critique of Pillar Design Equations from 1833 to 1990.
PB95105482

Publication Date	1994
Personal Author	Babcock, C.
Page Count	116
Abstract	When a flat-lying mineral deposit such as a coal seam is mined, some coal is left to separate the roof and floor so that miners and machines can safely mine the seam. The mineral left is in the form of mine pillars. If too much is taken, support problems and unsafe working conditions result. If too little is taken, the mining operation will be unable to compete economically with other mines. Therefore, one must select pillars of the optimal size to maximize mining recovery and minimize risk to miners and equipment. Later, if the pillar support is no longer needed and the surface can be allowed to subside the thickness of the coal seam, then the pillar support can be removed to increase mining recovery, and initial pillar size is not as critical. Only a small part of the information available on pillar design can be presented here. The purpose of this report is to summarize some of the work done by the U.S. Bureau of Mines and others on pillar design, which is reported in the literature from 1833 to the present, and present rock mechanics test results that aid in understanding mine pillar behavior. The variable names used are those of the authors cited. This results in multiple use of some variable names.
Keywords	Coal mining Underground mining Columns(Supports) Mining engineering Structural analysis Coal deposits Stress analysis Mathematical models Compressive strength Pillars
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries
Corporate Authors	Bureau of Mines, Denver, CO. Denver Research Center.
Supplemental Notes	Library of Congress catalog card no. 93-19066.
Document Type	Technical Report
Title Note	Information circular/1994.
NTIS Issue Number	199501