Waste Rock Piles can measure hundreds of meters in height and their failure can put life and property at extreme risk as well as significantly impact the surrounding environment. As such, waste rock piles should be considered structures, rather than dumps. Waste rock piles geometry and height is site-specific and govern the level of risk associated to its construction, operation and management. However, the design of these structures does not always garner the rigorous attention that they should be afforded. This paper provides practical nomograms for designing waste rock piles on solid competent foundations. In cohesionless soils, commonly placed using end-dumping methods, the stability of the stockpile slope depends on the angle of internal friction (Ø), slope angle and the height, for a given depth of critical slip failure. The nomograms presented herein are based on the requirement of attaining an overall factor of safety of 1.5 and a local factor of safety of 1.2.
Note that this white paper was the subject of a presentation at the Tailings and Mine Waste’18 Conference in Colorado State University.