Monitoring of structurally controlled deformations at the Kanmantoo copper mine

The Kanmantoo Copper Mine in the Adelaide Hills of South Australia was operated by Hillgrove Resources Limited from 2010–2019. The latest Giant Pit was a 360 m deep cutback with a 300 m high inter-ramp slope that had been steepened from 45o from the previous Kavanagh cutback to 57o. The western wall was monitored by various Maptek Sentry Systems over three years from 2016 to 2019. During this time, the wall underwent significant relaxation and encountered multiple rockfalls; the latter which increased in size and frequency as the pit bottom was approached. Maptek laser scanners were positioned at various locations to monitor the wall over the three years. Sentry was used to provide real-time monitoring and alarming capabilities. The Sentry laser scan data captured was analysed in Maptek PointStudio, to remotely map geological structures and identify rockfalls. These rockfalls ranged in size from several kilograms to more than 2,000 t. PointStudio was used to create a report from this data showing the complete mine life dilation and rockfalls that occurred during this period. This paper discusses the deformation history of the west wall, the relationship of these movements to the geological structure and to various rockfalls that occurred during the latter excavation stages.