A laboratory-based test procedure for the investigation of slaking-induced changes in geotechnical properties of tailing dam embankment materials

Abstract

Slaking is a process of material parameters alteration resulting from wetting-drying cycles, changes in overburden stress, and chemical interactions. Tailings Storage Facilities (TSF) constructed with materials prone to slaking may experience breaches, especially during the post-closure period, due to the deterioration of shear strength and permeability characteristics. Rockfill materials, particularly those containing clay components, can undergo various forms of crack formation, leading to disintegration as a result of wetting-drying cycles, stress increments, and intense compaction. However, there are currently limited methodologies available for replicating such material alterations on a laboratory scale. Therefore, a new large-scale laboratory testing approach has been designed to simulate variations in wetting-drying cycles, humidity, and overburden pressure, enabling the prediction of the slaking potential of TSF construction materials. This novel methodology replicates field drying-wetting cycles and variations in humidity and overburden stress in a controlled environment, allowing for the estimation of the deterioration of shear strength and permeability characteristics in rockfill materials.

Keywords

• Tailings storage facility
• Rockfill materials
• Slaking
• Drying-wetting cycles
• Shear strength
• Permeability characteristics