Effects of flow velocity and concentration on the overtopping failure mechanism of tailings dams

Abstract

The failure risk of tailings dams has significant impacts on downstream environments and safety. This study investigates the effects of tailings slurry concentration and inflow velocity on the failuring process of tailings dams through physical model experiments. Experiments were conducted under low-, medium-, and high-concentration slurry conditions with varying inflow velocities, focusing on the role of slurry fluidity in failure evolution. Discharge-time curves were analyzed to reveal dynamic characteristics of the dam-break process. Results indicate that as slurry concentration increases, fluidity decreases, prolonging the failuring process and reducing discharge rates. Inflow velocity significantly affects the initial failuring rate, with higher velocities accelerating failure expansion. The study demonstrates that slurry concentration and fluidity critically influence erosive capacity during failuring, particularly under low viscosity conditions where failuring becomes more intense. Higher inflow velocities exacerbate failure development, leading to severe dam erosion. Rational control of slurry concentration and flow velocity can effectively mitigate tailings dam failure processes, reducing downstream hazards. This research provides experimental insights for discharge prediction and disaster mitigation strategies during tailings dam failures.