Los Andes, Chile
Codelco is the world’s largest producer of copper, mining over 1.400.000 metric tons (1.6 million tons) annually; 11% of the world total. With a $1 billion expansion of its Adina mining facility located 4.000 m (2.5 mi.) above sea level in the Andes Mountains, Codelco maintains its status of owning the world’s largest copper reserves.
The contractor chosen for the project requested from EFCO the study, design, and provision of equipment– for both the wall forming and slab shoring solutions– for the construction of an access tunnel to the underground galleries of the Codelco Andina mining facilities.
EFCO designed a first stage of double-sided walls with the lightweight and versatile HAND-E-FORM® system, each pour at a height of 4,8 m by 12 m long (15′-9″ x 39′-4″).
The pyramidal configuration and the complication added by the traffic of heavy vehicles, for the slab shoring, EFCO designed a special shoring solution using SUPER STUD® frames with pipe braces. Over these frames, a grid of main and secondary beams was installed. Adjusting for the incline of the slab, the contractor used the EFCO standard swivel head screw jack mounted to a SUPER STUD. To eliminate concrete from seeping down the slope, it was necessary to install an exterior forming lid on both sloping sides of the slab.
The project management was very satisfied with the performance of the EFCO systems, especially considering the difficult site conditions, 4.000 m (2.5 mi.) above sea level, temperatures below 0°, combined with snow and a scarce labor force.