Finite element modeling of a PE pipe heap leachate collection system

Results of finite element modeling for a series of corrugated polyethylene pipes under a typical 120 m high heap leach pad of copper bearing ore are presented. The modeling results for two different configurations illustrate the phenomena of soil structure interaction between the ore and the pipes. A trenchless configuration showed significantly smaller radial soil stresses at the springline of the pipes when compared to a shallow trench configuration with the pipes laid within a trench. Radial soil stresses at the crown and invert were of similar magnitude for both configurations. Circumferential stresses within the soil around the pipes were also similar. Pipe thrust and bending moment at the invert location were significantly reduced in the trench-less configuration.