Flow Failure of Filtered Tailings Under Monotonic Loading

The use of filtered tailings has increased in the last two decades throughout the world. 

This technology has advantages over other types of tailings disposal. For example, an increase in water recovery and improved physical stability. Moreover, it is possible to develop co-disposal schemes by mixing filtered tailings and mine waste.

However, specific studies on the mechanical behaviour of filtered tailings at large deformations, such as the evaluation of stress-strain behaviour, stress path and determination of the critical state line, are scarce. 

These characteristics are important since they control the susceptibility of the filtered tailings facilities to failure due to flow liquefaction and allow an adequate stress-strain modelling. 

Therefore, this paper aims to fill this gap by using triaxial samples with and without drainage under monotonic loading until axial strains of up to 20% in remoulded samples at different levels of density and effective confining stress. 

The results allowed the identification of a possible strain-softening behaviour in filtered tailings. In addition, the conditions where the material behaves contractively were defined.