July 10, 2025, North Bay, ON, Canada – Ryan Weir, a senior engineer at Knight Piésold Canada, presented a risk-based approach to mitigating legacy geomechanical mine hazards at the 59th U.S. Rock Mechanics / Geomechanics Symposium of the American Rock Mechanics Association (ARMA).

The symposium, held on June 8-11, 2025, in Santa Fe, New Mexico, focused on theoretical advances and applied research in rock mechanics and geomechanics relating to civil, mining, geothermal, interdisciplinary, conventional petroleum, unconventional petroleum, and storage and sequestration. 

Weir presented the paper “Prioritizing the mitigation of legacy geomechanical mine hazards using a risk-based approach,” which was co-authored by Ben Peacock of Knight Piésold Canada. His presentation, during the rock hazards and risk assessment session, outlined an approach for effectively managing hazards facing hundreds of thousands of legacy mine sites in various stages of closure across North America.

Legacy assets often include potential hazards, such as crown pillars, slopes, raises, and portals, that pose risks to safety and the environment. Since comprehensive rehabilitation of these hazards is time-consuming and expensive, it has become critically important for mining companies and governments to optimize the use of their resources while managing an increasing number of legacy assets.

The process consists of the identification and initial classification of mine hazards, the investigation of the hazards, the refinement of the initial risk assessment, and the selection and implementation of mitigation measures.

“This approach has been used successfully at numerous mine sites across North America,” said Weir. “It provides mine operators and regulatory agencies with an objective, transparent, and actionable framework for prioritizing rehabilitation efforts in a way that maximizes both safety and resource efficiency.”

In addition to Weir’s presentation, Knight Piésold participated as a bronze sponsor and exhibitor at the symposium, with Dr. Rami Abousleiman and Jorge Mendoza, project engineers at Knight Piésold USA, in attendance. Dr. Abousleiman also co-chaired the session on numerical modeling for mining applications and was appointed by the ARMA Board of Directors to serve as the ARMA Diversity, Equity, and Inclusion Champion for a two-year term.

“Sharing our approach with fellow rock mechanics and geomechanical practitioners at the ARMA symposium highlights the importance of knowledge exchange in tackling complex challenges facing the mining industry,” added Weir. “At Knight Piésold, we continue to support our mining clients throughout their assets’ full lifecycle—from early development through operations to closure—by applying technically sound, economically practical approaches tailored to each site's unique conditions and stakeholder requirements.”