An instrumented analysis of stope destressing at Creighton Mine

This thesis is an analysis of a destressing technique used during the production of stope 1299 on the 6400 level (1950 m depth) of Creighton Mine in October of 2004. Destressing was proposed for this stope due to stress related production problems within the previous stopes of this orebody. The primary goal of destressing was to reduce the stresses in the stope such that the production holes would remain intact and not require redrilling or cleaning.; The 1299 stope was instrumented and monitored throughout destressing and mining. The instrumentation program generated multiple results across a range of instruments. Seismic data, tape extensometer measurements and accurate camera surveys of the destress holes are presented in this thesis.; An analysis is made of the destressing using numerical modelling and the interpretation of the instrument data. The conclusions obtained relate to the success of the destressing, in this case, and to the applicability of extending the method of destressing to other mining scenarios with varying stress distributions.; The destressing attempt did not appear to be a success. However, the method of destressing is shown to have great potential. Recommendations are made in the thesis to improve the success of the destressing method. The thesis also shows that the results of the instrumentation, specifically the seismic data, are difficult to explain within the context of the numerical modelling.