Faculty of Engineering, Built Environment and Information Technology
School of Engineering
Department of Mining Engineering
Selected Highlights from Research Findings
Rock failure is a source of risk for any mining operation. Consequently, the ability to predict such failure has attracted the attention of many researchers. Prof Matthew Handley and his colleagues at the Department of Mining Engineering have conducted research aimed at assessing the probability of a specific type of rock failure: highwall failure caused by a phenomenon known as the Block Thrust Failure Mechanism.
A highwall is a feature of a typical open pit mine: it is an angled cut into the ground that provides a free face for blasting purposes. Highwall failure occurs when the rock composing the highwall loses its structural integrity. This can happen in various ways: the rock composing the highwall could slide out, topple, or collapse under its own weight.
The Block Thrust Failure Mechanism represents yet another way in which a highwall could fail. This process is more complex than any of the three failure mechanisms mentioned above: it occurs when fracture processes lead to the formation of a wedge-shaped block in the rock behind the highwall.
The sharp end of this wedge is pointed downward, and runs parallel to the face of the highwall. Thus, if the wedge is pushed down by its own weight, the highwall face is thrust outwards into the pit.
During their research, Handley and his team studied three failures in an open pit coal mine in South Africa. Based on the results of these studies, they were able to develop a simple yet accurate technique for assessing the risk of highwall failure. Their technique represents a significant improvement over currently accepted methods, and therefore holds considerable promise in terms of more stable slope designs
Contact person: Prof MF Handley.
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