Scale effects on dam-break analysis with flume test modelling

Tailings represent a significant liability in the mining industry. These materials typically contain a high percentage of water and are hydraulically deposited after mineral processing. Due to their fluid and non-Newtonian behaviour, tailings can bring challenges to dam-break analysis using scaled physical models, which may result in distortions and scale effects. This study aims to validate the use of physical flume tests in dam-break studies through dimensional and dimensionless analysis. Eighteen computational models were developed at three different geometric scales (1:1, 1:8, and 1:81). Deposit heights, scales, and solid concentrations were varied to evaluate driving and viscous forces effects on runout distance and repose angle. Results indicated that higher solid concentrations led to more pronounced distortions in both runout and slope angle. The greater the deposit height and scale, the less influence viscous forces had on results. From the dimensionless analysis, a flow region was constructed to estimate potential runout distances as a function of Buckingham numbers. Flume tests proved to be a viable approach for dam-break analysis; however, caution is required due to the potential for misleading results if scale-related distortions are not properly accounted for.