Deformation-Dependent Mechanical Response in Tailings Dam Failures

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In the last decade, a series of catastrophic tailings dam failures created a crisis of public trust in mining operators' ability to safely manage these structures. In response, the international geotechnical research community, led in part by Canadian geotechnical engineers, mobilized a concerted, comprehensive effort directed at reducing the incidence of such events to zero or near zero. This research program aims to contribute knowledge that will support the resource developers' efforts to attain a zero incidence of tailings dam failures. From recent tailings dam failures, it is becoming increasingly evident that critical aspects of mechanical response in these structures are deformation-controlled and involve a reduction of shear resistance. Recent cases where these effects played a critical role include the failure of the Mt. Polley TSF9,39, the Fundao dam failure24, the Cadia dam failure12, and the Feijao dam failure30. Furthermore, many of these structures were marginally stable prior to their failure, and catastrophic failure was brought about by relatively minor triggers36,37,39. This research program aims to expand our understanding of deformation-dependent mechanisms of instability in these structures. Its central question is, can the deformation history and other performance data of a stable tailings structure be used to reliably predict its future behaviour, including detecting the risks of failure, in response to changes imposed either by human activity (e.g., planned construction) or caused by environmental factors (e.g., rainfall). The applicant will seek answers to this question by replicating known deformation-dependent mechanisms of instability (e.g., loss of lateral confinement) under controlled conditions while closely monitoring them and replicating them in simulations. The work will involve a combination of laboratory testing (e.g., triaxial, direct shear, hollow cylinder tortional shear tests), large-scale laboratory physical modelling , performance monitoring and numerical analysis. HQP engaged in this project will become experts in numerical analysis of geomechanical problems and will learn the cutting-edge strategies for ensuring dam safety. Tailings dam failures disproportionately affect traditional and Indigenous communities. In Canada, the problem of tailings dam safety is linked to three issues: environmental protection, responsible resource development, and Canadian-Indigenous reconciliation. This research strikes at the heart of these issues. The intent is to build collaborations with mining operators and Indigenous communities and to bridge the interactions between the two by working towards the common goal of environmental protection in a manner that is respectful of traditional and Indigenous communities. The engaged HQP will receive training in traditional and Indigenous knowledge and will seek to learn how to integrate Indigenous participation the engineering practices related to tailings dam management.