Stability Analysis of Pillar in Underground Limestone Mine Using 3D Scanning Techniques

In this study, point-cloud data were obtained using a laser scanner for an underground limestone mine. A total of 581 discontinuities were extracted and statistically treated using the obtained point-cloud data, and a discrete fracture network was simulated and applied to the numerical analysis model. The stability was evaluated for two pillars located in large underground openings using the numerical analysis model. The evaluation results based on the safety factor and displacement showed that the safety factor tended to decrease as it progressed from the center of the pillar to the side wall. However, the pillars showed a minimum safety factor of 1.0 or higher. For the displacement, a maximum displacement of 9 mm occurred in a part of the pillar side wall. Nevertheless, the stability of the pillar was achieved, as it was insignificant compared to the size of the pillar.