October 18, 2024, Vancouver, BC, Canada – Kevin Davenport, a senior engineer at Knight Piésold Canada, recently presented valuable observation-based insight into the complex dynamics of block caving and mine-induced subsidence at the 9th International Mass Mining Conference and Exhibition (MassMin 2024).

The conference was held from September 15 to 19 in Kiruna, Sweden and brought together technical specialists from around the world to discuss the latest advancements in mass mining techniques.

Davenport presented the paper "Influence of Pre-Existing Mobilized Zones on B3 Cave Propagation and Initial Subsidence at the New Afton Mine,” which was co-authored by Corey Kamp of New Gold. His presentation summarized the observed Block 3 (B3) cave propagation and initial subsidence manifestation resulting from ongoing block cave mining at the New Afton Mine in British Columbia, Canada. Findings were presented using illustrative examples from available state-of-the-art monitoring instrumentation and remote sensing techniques employed at the mine.

B3 mining was initiated in mid-2021 and comprised New Afton’s second lift, located approximately 750 metres below ground and partially beneath the previously mined Lift 1 West Cave. B3 cave propagation resulted in mobilization of the overlying Lift 1 extraction level and existing muckpile, with increasing subsidence observed on surface. The timing and extent of B3 cave progression and initial subsidence expression were interpreted to have been significantly influenced by pre-existence of broken, mobilized material within the overlying West Cave muckpile and its associated subsidence zone.

The study shares experiential learnings and conclusions regarding interrelated block cave and subsidence behaviour, including the use of available monitoring methods for observation-based assessment of cave propagation, interaction with overlying mining areas, and the onset of surface displacements. It is the authors’ hope that these real-world insights will be of value to industry practitioners when designing and optimizing underground and subsidence monitoring programs and interpreting observational data to guide mine operations and evaluate risks associated with block caving.

“There is significant value in effectively leveraging monitoring data to guide caving operations and inform management of potential hazards,” said Davenport. “Learning from the wealth of operational experience across the industry is critical to the success of future, increasingly geotechnically challenging projects,” he continued. “I would like to express my thanks to New Gold for the opportunity to be involved in underground B3 cave monitoring at New Afton and for supporting the publishing of findings in the spirit of shared learning with other industry practitioners.”

Knight Piésold offers geotechnical engineering, performance monitoring, and instrumentation services for operational mining projects, including those specialized to block caving and mine-induced subsidence applications.

Davenport added, “Our experience allows us to support mining companies to effectively leverage their monitoring data to inform management of risks and enhance operational efficiency and safety. Contact our team to learn more or discuss how we can add value and expertise to your project.”

To download the paper and conference proceedings, visit the link below.

Davenport, K., & Kamp, C., Influence of Pre-Existing Mobilized Zones on B3 Cave Propagation and Initial Subsidence at the New Afton Mine, in Johansson, D., & Schunnesson, H. (Eds.). (2024). Proceedings of the 9th International Conference and Exhibition on Mass Mining, MassMin 2024. pp. 1239-1254, https://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-110088.

Download