Jacking of roof section, Pascua-Lama, Chile and Argentina border
ALE has completed the jacking of 1,500t roof sections at the remote Pascua-Lama mine in the Andes mountain range.
Services required: The huge 90m x 210m stockpile building roof was located at 4,200 metres altitude, making the environmental conditions extremely harsh and challenging. Because of the location of the mine, wind speeds can build up to speeds of 150 km/hr and temperatures fluctuated between -40oC and 30oC. In combination with a relatively light roof with a large area, additional precautions had to be taken.
All of the girders were pre-assembled into 40t heavy truss sections in the city of San Juan at normal altitude, which then required ALE to transport them safely through remote mountain roads to the mine. These were then assembled to form the complete roof at a low elevation on temporary building supports.
At each side of the stockpile building four 200 ton strand jacks are installed cross wise, to withstand the forces that could occur when wind would pick up. When the roof is jacked up to
the required height, the strand jacks were tensioned. A hydraulic skidding system was used to support and move the side girders inwards.
The jack up operation, which consisted of 22 layers of beams, was completed in less than six hours.