Work on a US$450 million tunnel project in Buenos Aires has been started by Italian contractor Salini Impregilo, it is part of the biggest public works in Argentina.
The 12 km tunnel will pass beneath the Riachuelo River, and is intended to return urban wastewater to the river.
The scope of the work to be undertaken by Salini includes a 10.5 km tunnel, with an internal diameter of 3.8 m; a 50 m-deep load shaft at one end of the tunnel, as well as a return shaft at the opposite end; and a 1.5 km-long diffuser system, anchored in the river bed.
The tunnel will be dug at a depth of 40 m, in the bed of the river, using a double-shielded TBM with an internal diameter of 4.1 m.
Around 550,000 m3 of earth is being moved by Salini and 7000 m3 of concrete is being utilized on the project.
The result of the tunnel development is that it will enable the decontamination of the Riachuelo river basin, which in the past has been affected by industrial activities – including paper mills and tanneries which have been duping process by-products into it for many years.
Funding for the project – part of a wider initiative to promote sustainable development of the Matanza-Riachuelo catchment basin – has come from the World Bank.