A Practical Modeling Approach using Room and Pillar Mining Method for the Exploitation of Ankpa Coal Deposit

The aim of this research is to design underground workings using a room and pillar mining method for the extraction of Ankpa coal deposit in Nigeria. Representative samples for each lithologic unit were collected from the Ankpa coal mine formation and laboratory test was carried out to determine their geotechnical properties. These tests were carried out in accordance to ISRM suggested methods, and were used as input parameters to describe each geomaterial in the RS3 finite element geotechnical software. The Rocscience RS3 three-dimensional numerical design tool was used to correctly model the coal formation, design the excavation and to analyze the stability of the excavation. The underground working was developed in four stages, and the result for maximum effective principal stress and total displacement was computed. The maximum effective principal stress value of 5295.71 kPa was attained. The stress was concentrated at the middle of the developed mine panel, while the overall total displacement is 0.019 m. The model shows a promising design with good stability if it is lightly supported at the center of the stope