Developing Geological Structural Criteria for Predicting Unstable Mine Roof Rocks.
NTIS: PB 276 735 Available for Reference At Bureau Libraries :249 pages
This study was designed to investigate roof falls in room-and-pillar drift coal mines and to determine geologic methods for predicting unstable roof conditions. Correlations were made laterally between surface outcrops and within the mines using lithologic and trend analysis criteria. Lithologic criteria compared cyclic changes in roof strata. Results indicated that roof falls are associated with zones of weaknesses within or between five vertical cycles recognized. Abrupt lateral facies changes occur. A direct relationship between joint and slip frequency and direction with sandstone roll trends was found. Surface joints compared well with drainage segments, but did not correlate with roof falls in areas of mines under overburden in excess of 600 feet.
CP; Final Contract Report;
NTIS Accession No.
NTIS: PB 276 735 Available for Reference At Bureau Libraries
Moorhead State University