Legote, C.2015-09-302015-09-302015-04Legote, C 2015, 'Mining through areas affected by abnormal stress conditions at Syferfontein Colliery', Journal of the Southern African Institute of Mining and Metallurgy, vol. 115, pp. 265-269.0038-223X (print)2225-6253 (online)http://hdl.handle.net/2263/50102Paper written as project work carried out in partial fulfilment for BEng (Mining Engineering) degree.This paper investigates the conditions leading to the indefinite termination of production in four critical primary panels at an underground coal mining operation, the observed shortcomings in the mining approach, and the proposed strategy to mine through the affected panels. Initial assessment of the abandoned panel conditions indicated time-dependent strata failure, (i.e. bolted roof failure overrunning intersections), which occurred from mere minutes to up to four weeks post-production, with and without prior warning of failure. This prompted the constant re-supporting of back areas, which raised safety and productivity concerns. Investigation of the initial mining conditions revealed that the failures were due to a critical combination of factors, the chief of which was isolated horizontal stress. Other factors that were initially overlooked by the mine (i.e. influence of hydraulic stress, misinterpretation of borehole data), resulted in the conditions being described as abnormal. Remedial actions were determined, and in so doing, a new strategic approach was formulated to thoroughly address all failure concerns. The four panels were explicitly planned to serve as the main intake and return airways for the recently commissioned secondary ventilation shaft, as well as providing access to millions of tons in proven coal reserves. It is thus imperative to mine the panels. A feasibility study showed that the proposed strategy set for implementation would be financially viable.en© The Southern African Institute of Mining and Metallurgy, 2015Critical primary panelsTime-dependent strata failureHorizontal stressProven reservesTermination of productionEngineering, built environment and information technology articles SDG-04SDG-04: Quality educationEngineering, built environment and information technology articles SDG-08SDG-08: Decent work and economic growthEngineering, built environment and information technology articles SDG-09SDG-09: Industry, innovation and infrastructureEngineering, built environment and information technology articles SDG-12SDG-12: Responsible consumption and productionEngineering, built environment and information technology articles SDG-13SDG-13: Climate actionArticle