Mine roof condition and the occurrence of roof falls in coal mines

Journal Article · Fri Jun 01 04:00:00 EDT 1984 · Ohio J. Sci.; (United States)

OSTI ID:6179570

Smith, A D

Mine roof fall characteristics of 250 falls in 5 different room-and-pillar coal mines, located in Pike, Martin, and Floyd counties, Kentucky, were investigated to determine the relationship of selected parameters associated with roof failure and the assumed condition of the mine roof before failure. The selected parameters used in the study included: presence of cracks and water before the occurrence of fall, sloughing of coal ribs, floor heave condition, type of roof support distance to coal face, and time of occurrence of fall after initial coal extraction. In addition, 8 research hypotheses, utilizing multiple linear regression techniques, were generated to test the relationship among the selected parameters and mine roof condition. The results indicated that the vast majority of falls portrayed some presence of water before the actual fall, occurred in less than 30 weeks after initial coal excavation, located usually greater than 30 m from nearest coal face, gave evidence of cracks in mine roof before occurrence of fall, generally portrayed a good roof condition before the fall, showed presence of sloughing of coal ribs, and gave no occurrence of floor heave before occurrence of fall. In terms of the characteristics of the original support systems in the mine roof falls studied, most roofs were either supported by mechanical-anchor bolts or resin or full-column bolts; very rarely did the roof appear to fail if supported by posts or cribs. A detailed inspection of the hypothesis and model comparison results gave supporting evidence that the condition of the roof is not dependent on the usual indicators of potential failure, such as presence of cracks and moisture. Hence, a combination of factors that are not easily accessible to measurement, are the dominant factors in the determination of roof fall-potential areas. (15 refs.)

• OSTI ID: 6179570
• Journal Information: Ohio J. Sci.; (United States), Journal Name: Ohio J. Sci.; (United States) Vol. 84:3; ISSN OJSCA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
012000* -- Coal
Lignite
& Peat-- Mining
COAL MINES
CRACKS
FAILURES
FEDERAL REGION IV
HYDROGEN COMPOUNDS
KENTUCKY
MATHEMATICAL MODELS
MECHANICAL STRUCTURES
MINES
MINING
NORTH AMERICA
OXYGEN COMPOUNDS
PARAMETRIC ANALYSIS
ROOFS
ROOM AND PILLAR MINING
SUPPORTS
UNDERGROUND FACILITIES
UNDERGROUND MINING
USA
WATER