Slope Stability in Arctic Surface Mines

Abstract

In surface mines in the arctic, frozen ground adds complexity to the conventional approaches to slope-stability analysis. Stability of mine slopes depend on geological structures, geotechnical properties, ground-water conditions, and the presence of dynamic destabilizing forces. Frozen ground creeps and undergoes changes in thermal regime. A computer model, GEODYNE is used to simulate movement of a thaw front into the slope face when climatic temperature changes. Synthetic insulation, such as geotextile or extruded polysterene, can be used to prevent thawing of the mine slope. Heavy mining machines, such as draglines, shovels, drills, and trucks, require a stable pit slope for their operation. Factors of safety of frozen slopes with a dragline above the slope are analyzed. A slope at -4°C has a significantly higher factor of safety than a slope of 0°C in the Deadfall Syncline area of the North Slope of Alaska.