Anisotropy in glaciated soils and its effect on the stability of large embankments

人们通常认为，在冰川作用下形成的土壤（称为冰川土）上的大型路堤的稳定性和变形对路堤的方向不敏感。这一假设是基于岩土工程实践中普遍接受的概念，即冰积土的刚度和抗剪强度在水平面内是各向同性的。萨斯喀彻温大学（University of Saskatchewan）和代尔夫特技术大学（Technical University德尔夫特）的岩土工程小组最近进行的研究表明，冰川土壤在水平面上具有各向异性的强度和刚度。这一新发现可能对建立在冰川土壤上的大型冰碛物的变形和稳定性具有重要意义。阿尔伯塔的油砂和萨斯喀彻温省的钾矿是两个具有重大区域和国家经济意义的资源型工业的例子，它们广泛依赖于在冰川土壤上开发大型冰碛。在过去的二十年里，尾矿堆的过度变形和不稳定性已经成为萨斯喀彻温省钾肥工业的主要问题。然而，现场监测及其在预警系统中的使用并没有导致桩不稳定发生率的显著下降，这表明控制这些桩的变形和稳定性的基本机制尚未完全了解。借助实验室和现场测试以及计算机建模的综合方案，拟议的研究旨在更好地了解影响废物容纳装置和尾矿堆的稳定性和变形的机制，这将导致改进的现场监测方案和对现场监测数据的有意义的解释。钾肥生产和尾矿储存都需要可持续的基础设施，以对环境负责的方式进行。预计拟议的研究将导致不太容易出现不稳定和过度变形的情况，并且在规划、设计、建造、运营和管理方面具有更好的可持续性。

It is commonly assumed that the stability and the deformation of large embankments over soils formed during glaciation (called glaciated soils) are not sensitive to the orientation of the embankment. This assumption is based on the generally accepted notion in geotechnical practice that stiffness and shear strength of glaciated soils are isotropic within the horizontal plane. Recent research conducted by the geotechnical groups at the University of Saskatchewan [U of S] and the Technical University Delft [TUD] has shown that glaciated soils have anisotropic strength and stiffness in the horizontal plane. This new finding may have significant implications for the deformation and the stability of large embankments founded on glaciated soils. The oil sands in Alberta and potash mines in Saskatchewan are two examples of resource-based industries with major regional and national economic significance that rely extensively on the development of large embankments over glaciated soils. Excessive deformation and instability of tailings piles have become a major concern for the Saskatchewan potash industry in the last two decades. Field monitoring and its use in early warning systems, however, has not resulted in a significant drop in incidences of pile instability, which indicates that the fundamental mechanisms that control the deformation and stability of these piles are not fully understood. With the help of a comprehensive program of laboratory and field testing as well as computer modelling, the proposed research aims to provide better understanding of the mechanisms that influence the stability and the deformation of waste containment embankments and tailings piles, which will result in improved field monitoring schemes and meaningful interpretation of the field monitoring data. Sustainable infrastructure is needed both for potash production and for the storage of tailings in an environmentally responsible manner. It is envisaged that the proposed research would result in embankments that are less prone to instability and excessive deformation, and have better sustainability in terms of their planning, design, construction, operation and management.