LiDAR mapping of ground damage in a heading re-orientation case study

The Subtropolis Mine is a room-and-pillar mine extracting the Vanport limestone near Petersburg, Ohio,U.S. In February of 2018, mine management began implementing a heading re-orientation to better control the negative effects of excessive levels of horizontal stress. The conditions in the headings improved,but as expected, stress-related damage concentrated within crosscuts. The mine operator has worked to lessen the impact of the instabilities in the outby crosscuts by implementing several engineering controls.With the implementation of each control, conditions were monitored and analyzed using observational and measurement techniques including 3 D LiDAR surveys. Since the heading re-orientation, several 3 D LiDAR surveys have been conducted and analyzed by researchers from the National Institute for Occupational Safety and Health(NIOSH). This study examines(1) the characteristics of each 3 D LiDAR survey,(2) the change in the detailed strata conditions in response to stress concentrations, and(3)the change detection techniques between 3 D LiDAR surveys to assess entry stability. Ultimately, the3 D LiDAR surveys proved to be a useful tool for characterizing ground instability and assessing the effectiveness of the engineering controls used in the heading re-orientation at the Subtropolis Mine.