Abstract
During this research, a detailed study of several mines in the southern Appalachian coalfields was undertaken to determine the most prominent geomechanical factors affecting roof stability and to evaluate their influence in promoting unstable ground conditions. To accomplish this task, the major geological and geomechanical features found to be detrimental to coal mine roof within the Appalachian Basin were identified and mapped in four Virginia mines. Statistical processing by chi-square and regression analysis was used to determine the influence of geology, mine layout, and support methods on roof stability. It was found that some easily determined parameters can be successfully used to predict potentially unstable areas. A simplified roof classification system was developed based on these geomechanical parameters, which can be used to assess the stability of a particular roof type. A roof rating index was also devised capable of expressing the probability of a failure under a given set geomechanical condition.
