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

原材料的提取伴随着大量废品的产生，这些废品包括矿物固体、工艺水和化学物质。这种通常是有害的污泥，被称为“尾矿”，被泵入巨大的土池，即所谓的尾矿储存设施(TSF)，通常达到很大的规模。TSFs的失效会导致废物的无节制排放，对环境和人类造成灾难性的影响，并造成巨大的经济损失。与蓄水大坝不同，在蓄水大坝中，如果结构完整性受到威胁，水可以被排放出去，而TSF必须永久屹立不倒。然而，世界范围内灾难性故障的高比率--在过去60年中每十年约有20起故障--清楚地表明，TSFs远远没有满足这一要求。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TSFs稳定性的主要危险，具有极端后果。对尾矿库中相应的破坏机理认识不足是导致尾矿库破坏的一个主要因素。因此，迫切需要提高我们对尾矿在单调和循环加载下的力学响应的基本理解，我们在描述尾矿的有效性方面的有效性，以及我们对TSF进行建模和模拟以评估其失效触发因素、机制和前兆的能力。这项建议回应了降低TSFs故障率的迫切需要。更具体地说，这项研究的目的是在申请人和他的HQP团队在岩土材料本构和数值模拟这两个核心领域开展的先前工作的基础上，为TSFs的稳定性分析及其失败风险这一具有挑战性的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，以及对液化和非液化尾矿的行为进行建模是本研究的重要部分。特别是，这项研究将包括尾矿材料的有效本构模型及其在通用计算平台中的数值积分，以基于健全的力学对尾矿和TSF进行建模，以评估它们的稳定性和失效风险。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，将培训4名博士生和2名MASC学生，他们将得到NSERC DG的部分或全部支持，以及几名本科生、博士后研究员和来自合作机构的访问学生，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生命周期方面取得突破性进展，提高采矿业的可持续性，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.