Los Bronces Mine

Anglo American
Dragados S.A., Besalco S.A.
$6 million USD
August 2009 — November 2011
Services performed
Dr. Sauer & Partners provided conceptual design and basic engineering.
Los Bronces copper mine, an open-pit operation at an altitude of 3500m ASL in the Chilean Andes, planned to utilise a tunnel for further deposit exploration and development. The project consisted of an 8.2km tunnel link between Los Bronces and Confluencia, connecting two processing plants. By applying drill and blast methods, a chamber was prepared to launch a 4.5m diameter tunnel boring machine which took over further excavation. A difficult geological and hydrological setting, extreme weather conditions as well as the high altitude and the rough terrain, provided a challenging environment.
The geological setting is dominated by the volcanic activities of the region and includes magmatic rocks such as monzonite, andesite, and dacite.
Valparaíso, Chile


  • Tunnel construction with TBM on active mine site
  • Operating in high altitude under extreme conditions
  • Difficult geology and massive water ingress
TBM Tunnel Sur (http://www.construccionminera.cl/)

TBM Tunnel Sur (http://www.construccionminera.cl/)

Tunnel excavation with TBM

Tunnel excavation with TBM