Influence of the Interface on the Stability of a Heap Leach Pad: A Sensitivity Analysis
Authors: Wendy Romero1, Jorge Mendoza2
Conference: 2nd International Symposium on Tailings Deposits
Date: March 11-13, 2026
1 Knight Piésold Consulting S.A. de C.V., Mexico City, Mexico
2 Knight Piésold and Co., Denver, USA
ABSTRACT
The physical stability of a heap leach facility (HLF) is generally governed by the behavior of the geomembrane liner system "interface," intended to minimize seepage. In this work, "interface" refers to the geomembrane system comprising the sequence: soil liner (lowpermeability soil), geomembrane, and ore or drainage layer (overliner). Due to the specific composition of the interface, it is crucial to characterize its behavior through proper sampling and appropriate laboratory testing. This article presents a sensitivity analysis of the interface in the stability of an HLF during the closure phase, based on test results obtained during design. In the analysis, the properties of the ore, the overliner, the natural ground, and the HLF geometry were treated as fixed parameters. The results show the effect of the interface system on the overall stability of the HLF, quantified by factors of safety.
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