Engineering Study of Structural Geologic Features of the Herrin (No. 6) Coal and Associated Rock in Illinois. Volume 2. Detailed Report

摘要

This report summarizes the status of knowledge on the influence of the geologic and structural fabric of roof strata on roof stability in underground mines in the Herrin No. 6 coal. The report is based both on past investigations and on information collected during recent visits to active mines. The objectives of this study were (1) to identify and describe geologic conditions that influence roof stability, (2) to relate roof performance to the geologic structure by detailed study within selected mines, (3) to present information on areal distribution of comparable geologic conditions that influence roof stability, (4) to compile from literature and files geotechnical data that pertain to roof stability, (5) to collect samples from study areas by diamond drilling, (6) to show how to recognize, both in mines and in diamond drill cores, the various geologic features that influence roof stability, and (7) to propose areas of future research on the subject.