Consolidation performance of oil sands tailings: data-driven insights and practical implications for tailings landforms closure and design

Consolidating slurry-like materials, such as oil sands tailings, is challenging for mine operators. Effective tailings disposal requires understanding water flow, surface settlement, and consolidation behaviors (hydraulic conductivity and compressibility). This study evaluates the consolidation behavior of four oil sands tailings using five testing methods: multi-step large strain consolidation (MLSC), seepage-induced consolidation (SIC), geotechnical beam centrifuge (GBC), benchtop centrifuge, and filtration–consolidation (F–C) tests. Data variability was analyzed using error propagation, with each test in triplicate except GBC, which had one replicate. A hypothetical model scenario, based on publicly available data, assessed variability in long-term geotechnical predictions and tailings landform design using key performance indicators. Results show that GBC defines the lower boundary of compressibility, while SIC sets the upper limit, exhibiting lower compressibility than MLSC. Centrifuge testing provides the upper boundary for hydraulic conductivity, while F–C defines the lower. MLSC yields higher hydraulic conductivity than SIC, likely due to SIC’s higher hydraulic gradient. Compressibility is more affected by material properties, whereas hydraulic conductivity varies comparably across materials and testing methods. Uncertainty differs by method, with SIC showing the highest and centrifuge tests the lowest. Testing method choice impacts consolidation data variability more than tailings type, emphasizing the importance of test selection in performance assessment. This study underscores the importance of integrating laboratory testing, field observations, and modeling for accurate tailings management and design.