Henriquez, F & Navarrete, R 2023, 'Automated reinforcement of orepasses in the Andes Norte project', in J Wesseloo (ed.), Ground Support 2023: Proceedings of the 10th International Conference on Ground Support in Mining, Australian Centre for Geomechanics, Perth, pp. 333-344, https://doi.org/10.36487/ACG_repo/2325_22
(https://papers.acg.uwa.edu.au/p/2325_22_Navarrete/)
Abstract: After 118 years of operation, the emblematic worksite El Teniente, from Codelco, aims to expand its lifespan another 50 years via site exploitation through the Nuevo Nivel Mina project. The initial stage, the Andes Norte project (PAN), amounts to 2,020 million tonnes of reserves with average grades of 0.86% copper and 0.022% molybdenum. This will translate to more than 17 million tonnes of fine copper over the 50-year operation (which commenced in 2018). The configuration of the project comprises exploitation by the panel caving system, with an orepass system through orepasses inside the footprint streets and a level scheme typical of the El Teniente mine site: sinking, production, ventilation, transporting and crushing, and panel caving.
This article describes the construction methodology and mechanised shielding of the orepasses developed for the PAN. Based on excavation of the 1OP-X3AS shaft, which was unsuccessful due to the collapse of the orepass in the reaming stage of the final section, they were designed to improve the construction method. The reinforcement process started with shotcrete spraying using remote-controlled remote equipment. Then the sequence of mechanised shielding of the shaft (BMP) began and ended with concreting of the annular space between the shield and the walls of the shaft. The use of micropiles prior to the drilling of the pilot shot in some of the constructed pouring points was also analysed. Lessons learned and some particularities solved during their application in order to start the ore transfer system, written by the team of construction engineers who led its development, are included.

Keywords: orepass, mechanised shielding, automation