Two dimensional stability evaluation of a single entry longwall mining system

The purpose of this study was to determine whether a single entry is as safe for the development of longwail panels than the present double entry system at the Sunnyside Coal Mine near Sunnyside, Utah. The work is a joint effort by the U.S. Bureau of Mines in cooperation with Kaiser Steel Corporation and the University of Utah. The study included field instrumentation and measurements as well as data processing and interpretation. In-situ and laboratory tests were conducted to estimate the physical and mechanical properties of rock types present at the Sunnyside Mine. Theoretical studies included prediction of stress concentrations and failure zones as well as comparisons between theoretical and field measurements of displacements about mine openings. A finite element computer program was used for theoretical study, comparison of field data, and for simulation of face advance.