TOPOGRAPHIC STRESS PERTURBATIONS IN THE CARROLL HOLLOW COAL MINE, CARROLL COUNTY, OH

Carroll Hollow Coal Mine located in the Appalachian Plateau Province within Carroll County, OH is a shallow (200-500ft) underground coal mine. The mine has experienced a variety of small, unpredictable roof falls throughout the mine. Standard practices of predicting and controlling roof instability do not typically take into account quantitative analysis of stress perturbations due to topographic relief at the earth’s surface. In addition, geologic features, such as faults, joints, buried stream channels, can cause stress perturbations. Thanks to freely available LiDAR (Light Detection and Ranging) data from the Ohio Statewide Imagery Project we have constructed an accurate 3-D surface mesh to represent the topography around the Carroll Hollow mine. Using this surface mesh as a source of stress heterogeneity within the 3D boundary element program Poly3D, we compute the stress distribution at the mine depth. Mapping of geologic structures and roof falls will be made throughout the mine and then compared to the numerical calculation of the stress field. Based on these maps and measurements, remote loading and boundary conditions can be modified within the model until numerical calculations reflect the true state of stress throughout the mine. Ultimately an algorithm will be created in order to help future mining operations incorporate topography into roof stability forecasting during mine planning. With these resources it may be possible to aid in mine construction decisions as the mine is being excavated.