Abstract
Recent failures of tailings dams have raised the interest of the mining industry in evaluating the risk of flow liquefaction. The standard practice involves using limit equilibrium analyses to calculate factors of safety, assuming peak or residual undrained shear strength conditions. However, this procedure does not account for the post-peak softening effect commonly observed in these materials.
This article applies a numerical procedure to evaluate the susceptibility of triggering flow liquefaction in a real dam; the methodology involves the use of finite element models in Plaxis 2D and the advanced constitutive models HSS and NorSand, for comparison purposes. In the example shown, the dam construction sequence is modeled in detail, and trigger analyses are carried out for various scenarios.
A comparison between the two constitutive models is presented in terms of loads triggering progressive failure, kinematics of failure mechanisms, and stress paths. Results demonstrate that both constitutive models produce results that are useful for evaluating the vulnerability of dams to flow liquefaction.
