Assessment of roof fall risk during retreat mining in room and pillar coal mines

One of the most challenging safety problems in room and pillar coal mines is roof fall phenomena during retreat mining. Roof fall not only causes fatal and non-fatal injuries on miners, stoppages in mining operations and equipment breakdowns, but also results in inefficient recovery of ore reserves. As a result, development of a methodology for risk assessment of roof fall has a remarkable role on safety of retreat mining. In this paper, at first all effective parameters on roof fall during retreat mining are identified and then the role of each parameter on roof fall occurrence is explained. Afterwards, a practical methodology is developed for assessment and control of roof fall risk using semi-quantitative techniques. Finally, this methodology is applied in main panel of Tabas Central Mine, located in the mid-eastern of Iran, and various possible scenarios of retreat mining and corresponding risks are evaluated. (C) 2012 Elsevier Ltd. All rights reserved.