Understanding, characterization, modeling, and simulation of the spontaneous failure of tailings dams

原材料的提取与大量废物的产生密切相关，包括矿物固体，工艺用水和化学物质。这种通常被称为“尾矿”的危险污泥被泵入大型土池，即所谓的尾矿储存设施（TSFs），这些设施通常尺寸很大。TSF的失效导致废物的不受控制的排放，这可能对环境和人类产生灾难性的影响，并造成巨大的经济损失。与用于蓄水的水坝不同，如果结构完整性受到威胁，水可以排放，TSF必须永久存在。然而，全世界灾难性故障的高发生率-在过去60年中每十年约发生20次故障-明确地表明，临时安全设施远远不能满足这一要求。TSF失败的原因主要是岩土工程。具有静态或动态触发的液化是威胁TSF稳定性的重大危害，具有极端后果。对尾矿坝破坏机理的认识不足是造成尾矿坝破坏的主要原因。因此，迫切需要提高我们对单调和循环载荷下尾矿的机械响应的基本理解，我们在尾矿表征方面的有效性，以及我们在TSF建模和模拟方面的能力，以评估其失效触发因素，机制和前兆。 这一建议回应了降低临时安全设施故障率的迫切需要。更具体地说，在申请人及其HQP团队在岩土材料的本构和数值建模两个核心领域开发的先前工作的基础上，本研究的目的是为TSF稳定性分析及其失效风险的挑战性问题开发新的解决方案。了解尾矿材料的液化，预测液化的开始，并模拟液化和非液化尾矿的行为是本研究的重要组成部分。特别是，该研究将包括尾矿材料的有效本构建模及其在多功能计算平台中的数值积分，以便对尾矿和TSF进行合理的基于力学的建模，以评估其稳定性和失效风险。拟议的研究利用了与领先的工业和学术机构正在进行的合作，并将培养4名博士和2名硕士学生，他们将部分或全部得到NSERC DG的支持，以及来自合作机构的几名本科生，博士后研究员和访问学生，他们将得到其他资金来源的支持。这项研究的短期和长期成果有助于在采掘业的生命周期中取得突破性进展，提高采矿的可持续性，并为加拿大创造附加值。

The extraction of raw materials goes hand-in-hand with the generation of large amounts of waste products, consisting of mineral solids, process water, and chemical substances. This often hazardous sludge, known as “tailings”, is pumped into massive earth ponds, so-called Tailings Storage Facilities (TSFs), which often achieve great dimensions. The failure of TSFs leads to an uncontrolled discharge of waste that may have catastrophic impacts on the environment and on human beings, and cause huge economic losses. Unlike dams for water storage, in which water can be discharged if its structural integrity is endangered, TSFs must stand in perpetuity. Nevertheless, the high rate of catastrophic failures worldwide - about 20 failures per decade in the past 60 years - demonstrates unambiguously that TSFs are far from fulfilling this requirement. The causes of TSF failures have mainly been geotechnical. Liquefaction, with static or dynamic triggers, is a major hazard threatening the stability of TSFs with extreme consequences. Inadequate understanding of the corresponding failure mechanisms in tailings is known as a major factor in tailings dam failure cases. There is, therefore, an urgent need to improve our fundamental understanding of the mechanical response of tailings under monotonic and cyclic loadings, our effectiveness in the characterization of tailings, and our capabilities in modeling and simulation of TSFs to assess their failure triggers, mechanisms, and precursors. This proposal responds to the urgent need to reduce the failure rate of TSFs. More specifically, building on the previous body of work developed by the applicant and his team of HQP in the two core areas of constitutive and numerical modeling of geomaterials, the aim of this research is to develop new solutions for the challenging problem of stability analysis of TSFs and their risk of failure. Understanding the liquefaction of tailings materials, predicting the onset of liquefaction, and modeling the behavior of liquefied and non-liquefied tailings are essential parts of this study. In particular, the study will include efficient constitutive modeling of tailings material and its numerical integration in versatile computational platforms, for sound mechanics-based modeling of tailings and TSFs to assess their stability and their risk of failure. The proposed research takes advantage of ongoing collaborations with leading industrial and academic institutes and will train 4 PhD and 2 MASc students who will be supported partially or fully by this NSERC DG as well as several undergraduate students, postdoctoral fellows, and visiting students from collaborating institutes who will be supported from other sources of funding. The short and long term outcomes of this research contribute to groundbreaking advances in the extractive industries' life cycle, increasing the sustainability of mining and generating added value to Canada.