Design and construction of large caverns for underground mine facilities in the Andes of Central Chile

摘要

The Division Andina of Codelco Chile owns the Rio Blanco and Sur-Sur mines, two porphyry cooper-molybdenum deposits located in the Rio Blanco Valley, at elevations between 3150 and 4200 m a.s.l. in the Andes of Central Chile. This valley is deep andnarrow with steep glaciated hillsides. Winter conditions are severe, and snow accumulation may be more than 10 m thick, with frequent snow avalanches affecting surface mine facilities and access roads. The Don Luis Primary Crusher and the SAG Mill caverns, some of the largest underground mine openings in South America, are part of the Expansion Project recently undertaken by Division Andina to increase production and to allow continuous operation during winter. This paper describes the geologic-geotechnical context, the structural/stability analysis, the corresponding geometric design and rock support, and construction methodology for these caverns.