Basic principles for stable gullies in the gold and platinum mines of South Africa

A gully is an excavation cut in the immediate footwall or hangingwall of the reef for the purpose of enabling the removal of rock from the face or providing access to the face for mining personnel or material1. The gully sidewalls and hangingwall often pose a serious stability problem in the gold and platinum mines in South Africa, since records of fatal rock-related injuries show that they are the site of the second-highest rockfall and rockburst hazard to miners after the stope face2,3. Gay et al.4 have indicated that most accidents in stopes occur within 10 m of the stope face and in the gullies which provide access to the working area. From a safety point of view, these are the two most important areas on a mine because of the difficulty in providing support close to the face and the relatively high density of personnel in these areas. Some of the published figures for proportions of rock-related fatal injuries in gullies are given in Table I. Based on figures presented by Roberts and Jager2, and Jager and Ryder5, differing proportions of accidents, summarized in Table II, occur in gullies in the respective mining regions. Despite the higher accident rate in the Carletonville Goldfield, there appear to be disproportionately few gully accidents, while nearly all gully fatalities are the result of rockbursts. The low proportion of fatalities being attributed to gullies does not in any way suggest that gullies are relatively safe in the Carletonville Goldfield, but that the apparently contradictory statistics are perhaps the result of reporting norms, or that the high level of seismicity in the Carletonville Goldfield results in the gullies being adequately supported for