عنوان مقاله [English]
Pillar design in underground coal mines is one of the extensive research fields in coal producing countries. Remained pillars with improper sizes lead to pillar failure during pillar recovery operation because abutment loads due to this operation result in a load increase on the pillars adjacent to the pillar line. Pillar failure is one of the main geotechnical hazards that may cause in workers injury, equipment break down and stoppage in mining operation. In this paper, a simple method is presented for coal pillar design in room and pillar mines. This method can estimate the value of various loads (including development and abutment loads) that pillars might experience throughout the mining process. Another advantage of this method is reducing pillar failure risk. Finally, the proposed method was applied for pillar design in main panel of Tabas Central Mine and based on it the optimum sizes of pillar were obtained 11.6×11.6 m.