Self-weight consolidation of slurried deposition: tests and interpretation

Slurry deposition is a common practice in several domains, ranging from the surface disposal of mine tailings to underground backfilling. The storage of dredged materials and fly ash is another important issue involving slurry self-weight consolidation. To adequately design the infrastructures and facilities, it is important to have a good knowledge of the evolution of the physical and hydraulic properties of such slurried depositions. Over the years, several methods of measurement have been proposed, including standard consolidation (oedometer) tests and seepage induced consolidation tests. For most cases, these conventional methods are not valid due to the modification or disturbance they cause to the internal mechanical and/or hydraulic system of the slurried deposition during the application of external hydraulic or mechanical solicitations. In this note, a method based on column tests is proposed. It is shown that the method is simple and easy to execute, with few requirements in terms of instrumentation. Results show that the proposed method is efficient in evaluating the evolution of the physical and hydraulic properties of slurried deposition on an impervious base. Equations for describing the evolution of physical and hydraulic properties are also proposed, and correspond very well to the experimental results.