Supporting collapsed and highly deformed areas of block cave extraction levels

Large deformations in deep mines occur due to the exposure of extensively damaged rock mass adjacent to an excavation. In order to properly simulate the support response in such conditions, the ground deformation must be captured accurately. The mechanisms of rock mass damage, dilation and deterioration must first be correctly simulated to produce a realistic tunnel deformation in three dimensions. Furthermore, the physical response of the support elements must be realistic.

In this paper, a multi-scale approach to mine deformation modelling has been described to improve the simulation similitude of ground support capacity and demand. Case studies were used to demonstrate the behaviour of several heavy support systems using this approach. Some support designs for squeezing ground were tested and the limitations and vulnerabilities of the support systems described. The modelling methods used to simulate the mine deformation, drive behaviour and support system response were discussed and some sufficiency requirements for similar analysis were highlighted.