Stability of large embankments founded on glaciated soils

萨斯喀彻温省是世界上最大的钾肥生产国。萨斯喀彻温省目前有10个钾肥矿在运营。萨斯喀彻温钾肥行业已受到监管，以尽量减少土地使用要求和尾矿堆的环境足迹。这意味着未来的任何尾矿沉积都必须在更陡峭的山坡上进行，并将堆高增加到50米以上。因此，确保尾矿库的稳定性变得越来越重要。钾肥行业已经经历了这些堆中过度变形和不稳定事件的增加。钾肥工业的反应是更加强调设计和安装现场监测系统，以指导尾矿的放置，并对过度变形和潜在故障提供早期预警。不幸的是，这并没有导致桩失稳发生率的显著下降。萨斯喀彻温省的许多钾肥尾矿堆建立在冰川土壤上，这些土壤相当坚硬，具有相当高的强度。因此，这些土壤在“正常”荷载条件下（如建筑物和其他类似结构施加的荷载条件下）不会接近破坏状态。然而，尾矿堆施加的载荷绝不是“正常”的。尾矿堆本质上是一个非常大的路堤，有可能导致它所处的冰川土壤的破坏。这些尾矿桩为研究冰川土壤在“接近破坏”加载条件下的响应提供了独特的机会，可以视为现场规模的试验设施。拟议的研究旨在利用尾矿堆的监测数据作为现场规模试验，结合先进的实验室试验和复杂的数值模拟，以更好地了解冰川土壤的破坏前变形行为。拟议的研究结果将导致在冰川土壤上建立的尾矿桩和其他大型结构（如水坝、桥梁、隧道等）的设计更安全，并大大节省建设和运营成本。

The province of Saskatchewan is the world's largest potash producer. There are currently 10 potash mines in operation in Saskatchewan. The Saskatchewan potash industry has been regulated to minimize land use requirements and the environmental footprint of the tailings piles. This means that any future tailings deposition must be done at steeper side slopes and by increasing pile heights in excess of 50 m. It is, therefore, becoming increasingly critical to ensure the stability of these tailings piles. Already, the potash industry is experiencing an increase in the number of incidences of excessive deformations and instability in these piles. The response of the potash industry has been to place greater emphasis on the design and installation of field monitoring systems to guide the placement of tailings and to provide early warning of excessive deformations and potential failures. This, unfortunately, has not resulted in a significant drop in incidences of pile instability. Many of the potash tailings piles in Saskatchewan are founded on glaciated soils, which are quite stiff and have fairly high strength. As such, these soils do not approach failure condition under 'normal' loading conditions such as those imposed by buildings and other similar structures. The loading imposed by a tailings pile, however, is anything but 'normal'. A tailings pile, which is essentially a very large embankment, has the potential to cause failure of the glaciated soil over which it is placed. These tailings piles provide a unique opportunity to study the response of glaciated soils subjected to 'near failure' loading conditions and can be regarded as field-scale testing facilities. The proposed research aims to use the monitoring data from the tailings piles as field-scale tests in conjunction with advanced laboratory tests and sophisticated numerical modelling to provide a better understanding of the pre-failure deformation behaviour of glaciated soils. The outcome of the proposed research will lead to safer design of tailings piles and other large structures (such as dams, bridges, tunnels, etc.) founded on glaciated soils and result in significant savings in construction and operations costs.