Pillar Stability Analysis at Missouri S&T Dolomitic Limestone Experimental Mine

The Missouri S&T Experimental Mine supports teaching and research initiatives in mining and geological engineering; is used by the U.S. Army and by the Department of Homeland Security for tests and research and; hosts more than 6,000 visitors each year for educational and public awareness purposes. The Experimental mine employs the room and pillar underground mining method to extract dolomitic limestone of Jefferson City formation. In room and pillar mines, pillars play a significant role to providing support of the overlying strata. Pillar stability analysis has previously never been conducted at this mine to date. Pillar stability analysis is critical for safety of miners and safe working conditions. This fundamental research seeks to employ the Fast Lagrangian Analysis of Continua in three dimensions (FLAC3D) to determine modulus of deformability affect pillar strength. The numerical model was calibrated with Obert and Duvall empirical pillar strength equation. A multi-variant regression has been used to established relationship between the modulus of deformation of the rock mass and the pillar strength for various pillar shapes and sizes. It can be concluded that the pillar cases at Missouri S&T Experimental Mine are stable irrespective of the modulus of deformability. This is partly because the overburden loads imposed on the pillars are low