| The objective of this research is to link numerically modelled regions of high Local Energy Release Density (LERD) to actual regions of damaged rock mass. This was accomplished by comparing available volumetric release energy changes, numerically modelled stress conditions, and observed rock mass conditions for alternative mine. An analysis of this type would thereby satisfy the objectives of general rock mechanics for underground excavation stability design by understanding the relationship between mine design, rock mass conditions, and energy stored in a rock mass.; At the time of the initial sill development, INCO's Creighton Mine design practice did not consider changes in energy that are associated with mining. By illustrating how the mining sequence relates to the LERD, it was possible to assess whether rock mass conditions existed where the pillars may be intact and capable of bursting.; On the 2073 m and 2134 m Level where rock mass conditioning procedures (destressing) were in early stages of development, regions identified as having high LERD (greater than 0.45 MJ/m3), and thus prone to rock bursting, were regions that eventually burst. On the 2195 m Level, rock bursting occurred at lower LERD values and mine extraction, suggesting that rock mass conditioning procedures were effective in influencing the rock mass behaviour. The LERD modelling also has the potential to provide valuable information on potential hazardous ground conditions that can be presented to the underground workforce to provide a safer work environment. |
