Chuquicamata, also called Chuqui, is the largest open-pit copper mine in the world. Located in Chile in the Antofagasta Region, 15 km north of Calama and 245 km north-east of the capital Antofagasta at an altitude of 2870 m above sea level. The Chuquicamata mine has almost exhausted its production capacity as an open pit mine, so much so that construction work on the underground mine began in 2012. The object of the project is the expansion of the underground Chuquicamata mine which aims to increase its production capacities and useful life. The contract concerns the expansion of the ventilation system of the Chuquicamata Underground mine. Contract CC-140 includes the construction of the main injection tunnel No. 15, the extraction tunnel No. 14, two by-passes with the existing ventilation tunnels and connection tunnels with the future vertical extraction/injection tunnels.