November 2, 2022, Vancouver, BC, Canada – Specialist engineers Dr. Salina Yong and Daniel Yang of Knight Piésold Canada, together with Justine Ealy and Christina Foster of KGHM, presented a case study of their collaborative work at the poster session of the 2022 International Slope Stability Symposium. The study described the management of a large-scale creeping instability that occurred at an open pit operation and the rehabilitation of the pit to resume mining operations. The symposium took place on October 17-21, in Tucson, Arizona, USA.

In the paper, “Managing Excessive Pit Wall Deformation of Weak Rock Mass,” an open pit operation in Nevada experienced rapid acceleration of a large-scale creeping instability of a weak rock mass that displaced material over a hundred feet and buried the main haul road. The instability was monitored early on using terrestrial radar to manage the risk, leading to no safety incidents or equipment losses.

Stability analyses were completed to evaluate the rehabilitation plans, which included re-establishing the haul road. The mine was able to resume mining operations, adapting and pivoting strategically to extract additional reserves while managing the creeping instability.

“The observational method played a critical role in the mine’s adaptive management approach,” said Dr. Yong, specialist geomechanical engineer. “The mine established a monitoring system at the first sign of instability and transitioned to state-of-the-art technology in a timely manner.”

“Together with KGHM, we were able to develop a successful action plan that evolved as new data became available and the understanding of the rock mass and site conditions improved.”

Yang, specialist geotechnical engineer, added, “The mine’s flexible mindset for impromptu adjustments and vigilance with real-time slope monitoring and inspections as well as continuous maintenance have been vital to managing the instability.”

“We have been supporting the mine’s geotechnical team since 2012 and continue to provide ongoing rock mechanics support to their open pit operations. At Knight Piésold, our specialists continue to work with state-of-the-art technology to support clients in making informed decisions for strategic mine planning, leading to safe, responsible open pit and underground mining operations.”