Numerical modelling and scientific visualisation – integration of geomechanics into modern mine designs

Abstract

As mines progress to depths for which the induced stress levels exceed the intact strength of the host rock, significant challenges related to rock mass instability must be met. However, given complexity and the scale of orebodies in deep mines, it is increasingly more challenging to predict/pinpoint where and when stress levels will become problematic. Prediction of where and when large scale instabilities will occur continues to be the ‘holy grail’ of rock mechanics in deep mining. There is no perfect solution; however, there have been a number of technological advancements that greatly helped to develop our understanding of rock mass behaviour and the risks pertaining to deep hard rock mines. It is recognised that at the mine scale, geology and material properties are not fully known, however, using past experience and sound engineering judgment, it is possible to use innovative tools and methodologies to arrive at a reasonable approximation of how a rock mass will behave at depth. The main goal of this paper is to provide an overview of how some of these tools and methodologies have evolved and are actively being applied to the planning of deep mines. Vale Canada Ltd.'s Creighton Mine will be used as a case study to demonstrate how these new techniques have contributed to a better understanding, and hence a better mine planning approach for hard rock mines at depth.