Glencore’s Antapaccay mine is located in the Espinar province, Cuzco, Perú. Tierra Group logged geotechnical, geological and geo-mechanical properties of drill core advanced in Antapaccay’s Northern Pit. Approximately 6,000 meters of core were logged. Specific samples were selected for geotechnical testing to measure rock and shear strength parameters. Information obtained in the field and laboratory were used to modify the pit slope design. The project lasted 7 months utilizing a 22-person Tierra Group crew.