Understanding and Predicting Static Liquefaction in Tailings

About the Presentation:

Liquefaction-induced failures of tailings storage facilities (TSFs) have resulted in catastrophic environmental and human consequences, as evidenced by significant events such as Fundão, Cadia, and Brumadinho. These incidents emphasize the need for reliable assessment methods to evaluate liquefaction potential within mine waste facilities. The upcoming presentation examines a TSF where prior liquefaction assessments have produced contradictory interpretations – some indicating contractive (liquefaction-prone) behavior, others suggesting dilative (more stable) responses.

This work investigates both conventional and advanced in-situ testing techniques, with an emphasis on cone penetration testing (CPTu) and state parameter (ψ) analysis. While empirical methods are widely used, they should be viewed as screening process.

To improve accessibility and transparency, the study uses the Widget method: a finite element modeling approach of cavity expansion that integrates CPTu data with the NorSand constitutive model.

The presentation will demonstrate how the Widget method enables better quantification of the in-situ state of tailings, helps reconcile conflicting screening-level assessments, and supports a clearer understanding of liquefaction risk within critical TSF zones.

About the Presenter:

Dmitri Bohach is an Engineering Intern with SRK Consulting (Canada) Inc., working with the Tailings team in Saskatoon, as well as a 4th year Geological Engineering student at the University of Saskatchewan. His work includes organizing and interpreting site investigation results, numerical modeling, slope stability analysis, and laboratory data interpretation to support the safe and sustainable design and management of tailings facilities.