Evaluation of the stability and suitability of artificial concrete pillars in long-hole open stoping at Al Masane Mine, Saudi Arabia

"This study introduces a novel method to stabilize active stopes in the long-hole open-stoping mining method. The approach addresses critical geotechnical challenges, including high-stress changes, squeezing, spalling, slabbing, and sloughing across extensive ore body sections. Using FLAC3D numerical modeling, this research simulates stope behavior before and after the installation of artificial concrete pillars. A detailed case study of crown and sill pillar mining is presented to highlight operational challenges and practical solutions. Numerical analysis revealed that artificial concrete pillar installation reduced the displacement zone by 99% and the convergence zone by 63%, significantly enhancing stope stability. These simulation results were validated using field measurements from tape extensometers on installed convergence pins, which demonstrated a 70% reduction in roof displacement and a 10% reduction in sidewall displacement. The overall research workflow encompasses baseline ground assessment, site preparation, artificial concrete pillar installation, field monitoring, and subsequent comparative numerical simulations. The strong correlation between the numerical models and field data confirms the effectiveness of artificial concrete pillars in improving safety and efficiency in underground mining operations. This integrated approach provides a clear framework for operational stability and informed decision-making in deep mining environments. In a nutshell, the study flow includes presenting the state of the ground condition before installing artificial concrete pillars, preparing the site, installing artificial concrete pillars, monitoring field measurements, comparing before and after, then performing numerical simulation, and comparing with field measurements.