Building on soft tailings : east lake TMF expansion

To accommodate an increased mine life at a northern Saskatchewan mine, an expansion to its existing tailings storage capacity was required. Innovative solutions were necessary due to operational and space limitations associated with the mine’s existing tailings management facilities (TMF). Specifically, staged construction of a waste rock containment dike directly over previously deposited unconsolidated tailings coupled with a complex seasonal tailings deposition plan for new tailings was required. Despite efforts to characterize the tailings foundation conditions, significant uncertainty remained regarding the variability of its properties. The impact of this variability was examined through a sensitivity analysis; however, in an effort to minimize risk, a full-scale test section was constructed within the existing facility footprint and across the most sensitive section of the tailings foundation. This paper presents the findings of the test section monitoring and overviews settlement and deformation back analysis completed to confirm and refine the dike design and overall tailings operational plan. It also provides a case study on how state-of-practice desktop analysis can be effectively coupled with field verification to support design.Applied Science, Faculty ofMining Engineering, Keevil Institute ofUnreviewedOthe