A study on design and the stability assessment of underground limestone mine using numerical analysis

ABSTRACT In this study, numerical analysis was performed to design a drainage system, conduct a stability assessment of the drift, and construct a layout of the drift planned to be developed in the future. Moreover, we determined the factors that affected the stability of the drift in underground limestone mines. According to hydraulic analysis, the drifts planned for the future development of test bed mines are located underground, and the amount of the groundwater inflow rate in the drift is predicted to increase rapidly. Therefore, the numbers of pumps and drainage wells need to be doubled. Based on the stability assessment of the drift, stability could be ensured with a factor of safety of 1.5 or higher, with the exception of some sections. In addition, it was determined that a minimum factor of safety of 1.0 or higher could be maintained for widths up to 12 m based on considerations of future drift development. Finally, the effects on the factor of safety were analysed by changes in the levels of factors applied to the stability assessment of the drift.