Stability Analysis of Pillars in Underground Limestone Mine Using Three-Dimensional Scanning Techniques

In this study, point cloud data were obtained from an underground limestone mine using a laser scanner. A numerical analysis was performed using discontinuous and continuous models, and the stability of two pillars located in large underground openings was analyzed. The safety factor was 1.0 or higher in both analyses, and the displacement was insignificant compared to the pillar size, confirming the pillar stability. Additionally, the safety factor of the discontinuous model was reduced by approximately 30% compared to that of the continuous model, and the displacement was increased by approximately 40%. The change in the safety factor was examined by applying the minimum, average and maximum mechanical properties of the investigated rock mass. The analysis determined that an average change of 50% occurred in the safety factor when the minimum and maximum mechanical properties of the rock mass were compared.