Nayanthara, PGN, Gallage, C, Rajapakse, J, Biyanvilage, DSSS, Rowles, T & Tuplin, E 2024, 'Investigating the transitional behaviour of tailings from a gold mine site in Australia', in AB Fourie & D Reid (eds), Paste 2024: Proceedings of the 26th International Conference on Paste, Thickened and Filtered Tailings, Australian Centre for Geomechanics, Perth, pp. 181-190, https://doi.org/10.36487/ACG_repo/2455_14
(https://papers.acg.uwa.edu.au/p/2455_14_Nayanthara/)
Abstract: Tailing dams can be considered as fragile structures and often result in catastrophic effects when subjected to liquefaction. The existing stability and liquefaction analysis of tailings within the critical state framework explicitly assumes a unique critical state line (CSL). However, recent studies have highlighted the presence of non-convergent compression paths and non-unique CSLs in a diverse range of soils commonly referred to as transitional behaviour. An analysis was made of an extensive series of triaxial tests conducted on filtered tailings from a gold mine site. To examine the potential transitional behaviour based on the effect of texture tailings specimens were reconstituted using moist tamping and slurry deposition methods. The results have shown the features of transitional behaviour in the studied tailings with evidence of non-unique CSLs. The scanning electron microscopy-based fabric study revealed differences in the particle arrangement inherent in the preparation method which might be the primary cause of the transitional behaviour. This study further highlights the need for re-evaluation of effects of fabric in preparation of laboratory element test specimens for CSL determination.

Keywords: critical state, moist tamped, reconstituted, slurry deposited, transitional