Geotechnical monitoring and modeling at Cuajone open-pit mine

The Cuajone porphyry copper deposit is located on the western slope of the Andes Chain in southern Peru at an elevation of 3500 m. The current 700-meter deep Cuajone open pit will eventually reach a depth well excess of 1000 meters, placing it in the “world class” range in terms of proposed mines. Most of the deep open pits in the world are experiencing some degree of slope instability, as does the Cuajone open pit. The geotechnical issues will become increasingly important as the pit expands. The displacement of the slope at the Cuajone mine is regularly monitored using various means at a different frequency according to the magnitudes of measured data. Based on the detailed geological information including cell mapping, a structural fabric model was developed in which major structures that have a predominant influence on the stability of the slope were incorporated. A UDEC analysis was then carried out and the slope behavior in the northeast sector of mine was examined. The mechanism of slides occurring at the Cuajone mine was also summarized. The purpose of the project is to ensure that mine production is being carried out in a safe environment.