Analysis of the climatic effects on the stability of a tailings dam

Resumo

Tailings dams are structures of significant economic and environmental importance in the Brazilian territory. These structures play the fundamental role of containing tailings, which consist of water and waste resulting from regional mining activity. The release of this material into nature results in serious environmental consequences. Additionally, in situations of dam rupture, downstream populations are subject to direct losses from the generated flood wave and indirect damages due to contamination of the groundwater that supplies nearby cities.
These structures have become the focus of more detailed investigations due to the increasing frequency of incidents and accidents. Recently, Brazil witnessed two significant disasters that resulted in substantial loss of human life and considerable environmental damage: the collapse of Barragem I at the Mina de Feijão in Brumadinho and the Fundão Dam disaster in Mariana, both located in the state of Minas Gerais.
Because of these two incidents of great magnitude, the analysis of mining dam stability and constant surveillance of these structures have become the focus of detailed investigations. Such analyses consider various factors, going beyond the consideration of the structure's geometry and the physical and mechanical parameters of the soil, also the evaluation of water presence in the dam through a flow analysis. The study of water presence in the dam is highlighted because it is closely related to the assessment of susceptibility to liquefaction, which was the main cause of the incidents in Mariana and Brumadinho.
Based on this, the present study aims to analyze the impact of precipitation on the stability of a mining dam. For this purpose, Plaxis 2D for numerical modeling will be employed, through which models will consider climate effects such as rainfall and evapotranspiration to obtain the desired results. The results will be presented in terms of the safety factor over time. The variation in stability resulting from climatic fluctuations will be studied.