Subsidence analysis of the SW Sector at El Teniente mine

Authors: Cancino, C; Alvarez, C; Jara, R Download Paper

DOI https://doi.org/10.36487/ACG_repo/2435_Q-02

Cite As:
Cancino, C, Alvarez, C & Jara, R 2024, 'Subsidence analysis of the SW Sector at El Teniente mine', in Daniel Johansson & Håkan Schunnesson (eds), MassMin 2024: Proceedings of the International Conference & Exhibition on Mass Mining, Luleå University of Technology, Luleå, pp. 1475-1485, https://doi.org/10.36487/ACG_repo/2435_Q-02



Abstract:
El Teniente Mine (DET) has been developed through the years using the panel caving method, resulting in a notorious subsidence crater at the surface. Since 2011, operations related to an open pit named “Rajo Sur” took place in the southern sector adjacent to the subsidence crater, resulting in operational interference with the underground mine. In 2019, a new open pit called “Extension Norte Rajo Sur” (ENRS) was being planned in the southwestern sector, mostly within caved material. Assessing the potential interaction with the underground operation was key for the open pit project. Estimations of the active subsidence became pivotal for strategic project planning, particularly in determining the transition timing between underground and surface mining. A geomechanical assessment of the surface subsidence was carried out through numerical modeling to support the development of the economical pit of ENRS by estimating the expected topography over the years. The model was calibrated to site observations for the 2012–2018 period in terms of cave propagation, subsidence advance, and topographic vertical changes. Subsequently, a predictive analysis for the period 2018–2025 was conducted. This paper describes the numerical assessment, calibration and main assumptions made to assess the surface subsidence at El Teniente Mine for the period 2012–2025 and compares predictions with the actual current topography available today, finding a good overall agreement.

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