Numerical analyses based on deformation modelling are becoming customary in assessing tailings dam vulnerability. These methods consider the generation of excess pore pressure due to undrained shear of contractive materials, driving portions of the dam beyond the instability line, triggering the undrained softening process leading to flow liquefaction. However, standard practice continues to be the split of drained and undrained behavior as if they were mechanically distinct realms.
This paper validates the approach of using finite element modeling in Plaxis 2D to evaluate the static liquefaction susceptibility of a Tailings Storage Facility (TSF). Using readily available features such as the HSS constitutive model and fully coupled analysis, this methodology seamlessly captures the generation of pore pressures within both saturated and partially saturated materials.
This study highlights the efficacy of incorporating coupled flow in mitigating the effect of mesh dependency and localization of undrained softening processes.
Furthermore, although the results exhibit time-dependency, they demonstrate that beyond a certain threshold a behavior resembling undrained conditions is captured, rendering loading rate irrelevant to the outcome.
