Seyedan, S, Arenas, A & Llano-Serna, M 2024, 'Advances in dam breach analysis appropriate for dewatered tailings storage facilities', 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. 247-256, https://doi.org/10.36487/ACG_repo/2455_20 (https://papers.acg.uwa.edu.au/p/2455_20_Seyedan/) Abstract: Dam breach analysis is an instrument that allows owners and designers to assume a failure of the tailings storage facility (TSF) and estimate its impact. The International Council of Mining & Metals recommendation is to base a breach analysis on credible failure modes. Historically the techniques to undertake dam breach analysis have been extrapolated from the water dam industry, assuming that tailings flow like water (i.e. a Newtonian fluid). Nevertheless, hydraulically deposited tailings may be more likely to present non-Newtonian behaviour. In addition, dewatered tailings constitute an additional layer of complexity in tailings flow properties. For example, dewatered tailings are more likely to develop particle-to-particle interaction, and hence, dilative and contractive properties of tailings are expected to play a more significant role during a potential dam breach. The last decade has seen the flourishing of non-Newtonian techniques and numerical packages. These techniques can better estimate the potential impact of non-Newtonian flows and have resulted in improved breach analysis for conventional TSFs. This study presents the results of a dam breach analysis applicable to dewatered tailings using the mud farming technique. The TSF is a project located in northern Australia. Mud farming was adopted to construct a structural zone upstream of the conventionally built embankments. To investigate the credible failure modes, runout, and loss of freeboard estimation, an emerging technique called the material point method was applied to capture large deformations such as those seen during dam breaching. Keywords: mud-farmed tailings, dam breach, liquefaction, tailings, consequence classification.