Back-analysis and chart creation as a graphical tool for the characterisation of cave interaction at División El Teniente, Codelco, Chile

Authors: Salgado Veliz, J; Barahona, M; Constanzo, H; Villarreal, M Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2465_13

Cite As:
Salgado Veliz, J, Barahona, M, Constanzo, H & Villarreal, M 2024, 'Back-analysis and chart creation as a graphical tool for the characterisation of cave interaction at División El Teniente, Codelco, Chile', in P Andrieux & D Cumming-Potvin (eds), Deep Mining 2024: Proceedings of the 10th International Conference on Deep and High Stress Mining, pp. 281-294, https://doi.org/10.36487/ACG_repo/2465_13



Abstract:
Codelco Chile’s División El Teniente mine has experienced over a hundred years of ore exploitation by underground mining methods such as block caving and panel caving. The challenges of the increasing depth have resulted in a series of problems which, from a geomechanical approach, can be turned into solutions that offer stability and security during operations which are progressing from mining a secondary rock type to a primary rock type. One of the main challenges for the productive sectors and projects in the short, medium and long terms is to establish mining activities adjacent to and below older sectors previously exploited. This has been a historical problem for the División mine as it causes changes in the stress field between the cavities in formation, and an increase in both the quantity and magnitude of seismic events in the pillars of rock between the sectors, creating a phenomenon denominated cave interaction. To overcome this and take preventative action to avoid a seismic event, a graphical tool called a ‘cave interaction chart’ was developed. Its objective was to determine the current and/or future state between cavities through the geometrical disposition amongst them using the recompilation of historical data at the mine alongside an analysis with 2D numerical modelling of the convergent and divergent cases (at the same and/or different heights). The following document shows the back-analysis undertaken and the criteria used to understand and order the historical data. It explains the specific numerical modelling associated with different conditions in which an interaction can be generated to explain the whys and wherefores of this graphical tool, which will be used to standardise and complement future studies regarding new sectors in the División mine.

Keywords: cave interaction, geomechanics, stress field, chart, seismicity, underground mining, back-analysis, numerical modelling

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