M.Sc. (Geology) / Analyses show that the effect of inter-panel lag on hanging wall instability is an important factor affecting rock-fall accidents and production losses in gold mines utilising segmented longwall mining methods. The study emphasises the effect of inter-panel lag on the development of mining-induced fractures which are considered a major contributor to hangingwall instability in geologically undisturbed ground. The geology and mining geometry at Western Deep Levels, Limited, particularly at the selected research site, is outlined. The data collection, which is facilitated by the use of stereo-photogrammetry and computer-aided data handling, is described. Three types of mining-induced fracture are evident. The effects of inter-panel lag and geological inhomogeneity on the orientation and density of the mining-induced fractures are illustrated and discussed. The effects of inter-panel lag length on energy release rate are demonstrated and discussed. Microseismic event location data analyses are used to elucidate the fracturing process that takes place in the rock ahead of the mine face. Practical suggestions regarding the reduction in number and length of inter-panel lags are made, in the light of recent developments in the field of rock-burst control.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:11243 |
| Date | 29 May 2014 |
| Creators | Hagan, Terence O'Neill |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
| Rights | University of Johannebsurg |
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