Hardrock burst mechanisms and management strategies

Abstract

Rockbursts occur as a direct consequence of underground mining or civil excavation. The general scale of their seismic disturbance and consequences depend upon known factors. However, uncertainty remains as to exactly when and where rockbursts will occur, as well as the effectiveness of ground support measures to fully mitigate their consequences. While the uncertainty in when and where is a dilemma shared with earthquake prediction, that associated with ground support capability is both a design and a management concern. Following a brief review of the known mechanisms that produce rockbursts, the paper explores the sources and scales of energy demands that characterize the risk of their damaging consequences upon underground excavations. We note that some of this risk continues to be associated with uncertainty with respect to rockmass properties and in situ stress, particularly in the context of deep mining. A review is presented of all available yielding ground support systems and their necessary design requirements, identifying practical weaknesses and limitations where these are known. The paper concludes with some suggested areas where further study and development could provide the ways and means to reduce the design uncertainty in managing rockbursts.