A local area within a highwall at Bald Mountain had an existing instability and rock fall hazard in the upper open-pit slope. This instability was potentially jeopardizing mining operations due to its location above a primary haul ramp for active mining. With a mine plan that increased use of this haul ramp for future mining activities, Bald Mountain sought to assess the potential risk of the instability, learn its impact on mining activities, and gain recommendations on an appropriate course of action for ongoing employee safety. In 2020, Barr was retained to provide an independent evaluation of this instability, ultimately delivering a project report of findings, slope analyses, and recommendations for moving forward.
To study the instability, Barr conducted a geological and geotechnical analysis and reviewed previously collected slope monitoring data with respect to precipitation before delivering our assessment of the highwall condition and geotechnical approach for slope instability. Additionally, Barr reviewed all aspects related to risk mitigation, including geotechnical and operational controls and practices, development of threshold movement rates, and industry best practices for mitigating geotechnical risk.