Current Practices for Slope Monitoring at British Columbia’s Open Pit Porphyry Mines
Open pit mining induces movements in the pit walls that are routinely monitored to evaluate their performance. Excessive or accelerating pit wall movements must be identified, as they may be a precursor to slope instability. There are a variety of monitoring technologies and associated monitoring practices used by mines to measure movements of the pit wall. In 2013, a questionnaire was sent to the six operating open pit Cu-Mo mines in BC to collect information about their operations and to investigate the similarities and differences between their slope monitoring techniques. Follow-up visits to four of the mines were conducted to verify the collected data.
This paper presents a summary of slope monitoring techniques and practices used by the mines. All of the mines use conventional total station survey instruments to measure the movements of prisms installed in their pit walls. Two of the mines have employed ground-based radar systems. Several mines are conducting trials with new monitoring tools. Pit wall displacement criteria used by the mines to make operational decisions in response to pit wall movement rates vary.