Steep-slope compaction at the foot of the Andes.

Chile is by far the most important copper-producing country in the world. Some 72,000 tons of copper ore per day are being mined near the town of Til-Til, 95% of which are deposited in the 5 square-kilometre large reservoir of Ovejería as slag. The construction of a dam wall was to increase the capacity of this natural reservoir, and to permit storage of the slag for the next 50 years to come.

A Chilean contractor built the reservoir’s southern boundary: a wall that is 32 m high and just under 3 km long. Sand extracted from the slag was used as the main construction material. The contractor’s engineers were looking for a compactor which would not only be capable of fully compacting the non-cohesive sand but would also offer full traction at an incline of 30°. Why? Because after completion of the dam wall, a ramp was to reach down from the crown by as many as 130 m into the adjoining valley, resulting in an incline of between 22° and 30°. Hamm’s single-drum compactor type 3412 with Hammtronic was virtually predestined to rise to the challenge. The Hammtronic system guarantees optimum traction of the compactor at all times, and effectively prevents the wheels from spinning regardless of the type, profile or incline of the ground to be compacted.

Working at the Ovejería dam wall, two single-drum compactors 3412 HT from Hamm were compacting some 7,400 m³ of sand per day. Six roller passes uphill were followed by final compaction at the foot of the ramp parallel to the dam wall. The contractor’s project manager was delighted with the compaction quality, “Thanks to the Hamm technology, we were able to achieve optimum and – more importantly – uniform density even in the steepest places. And what’s more, we didn’t even need a winch.”

Job site: Ovejería reservoir, Chile
Project length: 3 km
Project height: 32 m
Material compacted: 7.400 m³ of sand per day