Cave back evolution monitoring and evaluation of criteria to support extraction strategy

Authors: Zepeda, R; Cisternas, P; Constanzo, H; Cifuentes, C; Ortiz, A Download Paper

Cite As:
Zepeda, R, Cisternas, P, Constanzo, H, Cifuentes, C & Ortiz, A 2024, 'Cave back evolution monitoring and evaluation of criteria to support extraction strategy', in Daniel Johansson & Håkan Schunnesson (eds), MassMin 2024: Proceedings of the International Conference & Exhibition on Mass Mining, Luleå University of Technology, Luleå, pp. 470-480.



Abstract:
Until 2021 in El Teniente mine, we used two methods to directly verify the cave back geometry. 1)tunnels inspection at upper levels intersected by the collapse process, 2), analysis of the recovered core of long holes towards the cavity. Some limitations with these methodologies were due to the low or non-existent availability of tunnels at higher levels and the low drilling frequency of long holes for this purpose. This document presents a case study, focused on the periodic monitoring of cavity evolution and its relationship with the area incorporation and ore extraction in the Pilar Norte Mine. The main objectives of this study are the periodic monitoring of the cavity evolution relating it to mining activity, to determine a collapse criterion based on sensor displacement rate. The installed instrumentation not only allows measuring the limit of the collapse, but also makes it possible to determine the area prone to collapse before it occurs. To this end, the retrospective analysis of the disconnected devices has made it possible to establish thresholds in the movement rate established by these zones. In addition, a connection is established between mining activity and disturbances in the devices along the instrumented wells. This technical development already takes a period of two years of important data collection.