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

点击翻译按钮获取中文摘要

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.