Static liquefaction of tailings slopes triggered by basal creep in frozen foundations

Static liquefaction of tailings slopes is commonly assessed under triggers acting directly on the tailings mass, such as crest loading, slope steepening, or pore-pressure rise. In cold regions, however, frozen foundations may undergo time-dependent creep and thaw-induced deformation, providing an additional delayed trigger for instability. This study presents a preliminary numerical investigation of basal deformation as a potential trigger for static liquefaction in saturated tailings. A hydro-mechanical NorSand model was implemented in the Fortran-based finite-element code DisrocFROST to capture contractive response, pore-pressure generation, effective-stress reduction, and strain softening in loose tailings. The implementation was validated against a loose undrained triaxial compression benchmark. A two-dimensional tailings slope was then subjected to basal displacement obtained from a thermo–elasto–viscoplastic analysis of frozen geomaterials. The results suggest that imposed foundation deformation initiates plastic shearing near the base of the tailings and promotes the upward development of a connected shear band. Pore-pressure redistribution and stress-ratio localization occur along the same deformation zone, indicating a liquefaction-type mechanism. These findings reveal first order insights into the impact of thermal creep deformation of frozen foundations on the trigging of static liquefaction of tailings storage facilities in cold regions.