Considerations for 2D and 3D slope stability analysis for closure of a tailings storage facility

Authors: Pereira, N; Lines, SH; Arenas, A Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2415_38

Cite As:
Pereira, N, Lines, SH & Arenas, A 2024, 'Considerations for 2D and 3D slope stability analysis for closure of a tailings storage facility', in AB Fourie, M Tibbett & G Boggs (eds), Mine Closure 2024: Proceedings of the 17th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 529-540, https://doi.org/10.36487/ACG_repo/2415_38



Abstract:
Slope stability analysis during closure of a tailings storage facility is critical to ensure construction of a safe and stable landform that lasts into the future. One of the more widely used techniques for assessing slope stability is the strength reduction method (SRM). Using SRM, the Factor of Safety (FoS) of a slope is calculated by comparing the factored shear strength of the soil to the shear stress acting on the soil. Guidelines encourage the use of 2D analysis due to its simplicity (International Commission on Large Dam 2023). The simplicity being a key reason why they are the industry standard. However, the limitations inherent in 2D analysis such as not capturing the 3D effects of soil behaviour, stress states and spatial load distribution are an important consideration that requires detailed understanding of both approaches. This paper presents a case study of a single uniform slope loaded by a four-wheeled scraper during the closure of a tailings storage facility. The SRM analysis is carried out using FLAC3D. The results provide a comparison of a full 3D model in terms of FoS in comparison to a 2D analysis using the limit equilibrium method.

Keywords: slope stability, tailings storage facility, FLAC, FLAC3D, strength reduction method, strength reduction method

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