Meeting Formwork Standards In Mine Construction – Pica, Región de Tarapacá, Chile
Requirements for cast-in-place concrete formwork standards
The Quebrada Blanca mine is in the Tarapacá Region of northern Chile at an altitude of 14,500′ (4,400 m), 150 miles (240 km) southeast of Iquique and 930 miles (1,500 km) from Santiago.
Cast-In-Place Formwork
Quebrada Blanca is an open pit operation that leaches ores to produce copper cathodes at a solvent extraction and electrowinning (SX-EW) plant. The copper cathode is then trucked to the port of Iquique for distribution. Part of the expansion project of this mine, called Phase 2, corresponds to the construction of the Dry Area that was awarded to Echeverría Izquierdo Montajes Industriales S.A. As a long-time EFCO customer, they knew of EFCO’s cast-in-place formwork standards, quality of equipment, engineering expertise and experience in forming and shoring projects so they chose EFCO once again.
Concrete Wall Forms
Echeverría Izquierdo was in need of concrete wall forms for a Primary Crusher and a Tunnel. They contracted with EFCO to complete the construction of both structures.
Double-Sided Concrete Wall Formwork System
The Primary Crusher has a total height of 112′ (34 m) and five levels. EFCO designed the double-sided concrete walls to be formed with the PLATE GIRDER® system. The double-sided walls are mostly 20′ (6 m) and 23′ (7 m) high and, with the versatility of the PLATE GIRDER panels, were assembled into gangs and cycled efficiently.
Safe, Fast Shoring Construction Solution
EFCO’s E-Z DECK® shoring system combined with SUPER STUD®, Z-BEAM® and E-BEAM® decks were used to shore the floor slabs of the Primary Crusher. Due to its high-capacity load, the E-Z DECK system is ideal for this type of application, where the slab thickness varies from 2′-4″ (700 mm) to 5′-7″ (1700 mm).
Modular Tunnel Formwork
The Recovery Tunnel consisted of two 230′ (70 m) long tunnels with 23′ (7 m) high walls and a 6′-7″ (2000 mm) thick roof slab. EFCO’s innovative design used PLATE GIRDER panels to form the double-sided walls. This formwork is efficient on all foundation types and is easily moved and cycled in large gangs. The pour windows in the PLATE GIRDER panels were very useful in placing concrete in tall walls with dense rebar. Pour windows are also good for inspecting or vibrating concrete during pours.
Slab Shoring System
EFCO’s aluminum frame shoring system, E-Z DECK, with its high-load capacity of 20 kip (89 kN) per post, efficiently handled the slab shoring needed for the roof slab of the Recovery Tunnel. For lease or sale, the E-Z DECK shoring system is designed to reduce labor and shorten construction cycle times. ◊
