This conference paper presents a full 3D limit-equilibrium model of a large mine waste dump in Peru with 11 heterogeneous soil layers. Reyes & Parra show that the 2D minimum factor of safety was misleadingly low because the true 3D failure surface crossed stronger units not captured in 2D sections. Their 3D model produced a 14–18% increase in FS, demonstrating how 3D geometry, variable stratigraphy and realistic slip-surface development significantly influence stability.
