Abstract
Development of heap leach facilities in some project settings can be very challenging. Currently the standard of practice for heap leach facility slope designs is the use of the limit equilibrium analysis method, which does not consider strain development in geomaterials, specifically the heap leach material and the interface between the geomembrane liner system and the heap leach material. Using finite-element-method modeling, this paper considers multiple engineering applications in design and construction of heap leach facilities where consideration of shear strains within the geomaterials is crucial for the overall performance of the facilities during operations and into closure. The engineering issues considered in the paper include 1) downdrag stress and strain development over liner slopes with varying subgrade gradients, 2) impacts on a liner system due to different overliner placement and ore stacking practices, and 3) risks of strain softening and slope instability when stacking fresh (unleached) heap leach material over saturated previously leached lifts under large vertical stresses. The results of the analyses presented in this paper demonstrate that, stress and strain development in geomaterials should be considered. The recent failures of leach pads around the world reinforce this assertion.
Authors
Peter Yuan | SRK Consulting US
Omar De Santiago | SRK Consulting US
Joshua Sames | SRK Consulting US
Tarik Hadj-Hamou | SRK Consulting US
