Authors: “G.K. Macqueen, E.I. Salas and B.J. Hutchison”
Grange Resources Ltd have been utilising radar monitoring since 2007 at their Savage River mining operation in Tasmania, Australia. Radar has provided prior warning of several large wall failures in the brittle amphibolite of the North Pit’s east wall, and these experiences have increased the confidence in the radar’s capability to provide reliable prior warning of large wall failures. With the increased confidence in the radar attention has focused on the remaining sources of risk in the forms of human error through mistakes in the application of the radar and human error in the form of ‘slips and trips’, particularly within software settings. These potential sources of human error are mitigated with the use of Standard Operating Procedures, Trigger Action Response Plans, training and checklists.
Radar monitoring of the east wall of North Pit has been found to have limited capability in providing prior warning of small wall failures. In order to mitigate the risk posed by small wall failures, remote controlled mining capabilities (including remote drilling, dozing, excavating, and blasthole loading) have been adopted for routine use within specified zones at the toe of the pit wall.
This paper describes how through applying appropriate radar alert thresholds across the entire pit wall, whilst ensuring the integrity of the radar monitoring system, and mitigating the risk posed by small wall failures, the risks of operating beneath a hazardous pit wall can be significantly reduced.