Argentina celebrates start of Agua Sur project 29 Jun 2020

A cutterhead lowering ceremony was witnessed by the President of Argentina Alberto Fernández and several Government officials, to mark start of the multi-billion-dollar Agua Sur system that will bring fresh water for 2.5 million inhabitants in the southern metropolitan area of Buenos Aires. The cutterhead was lowered to complete assembly of the first of two 4.66m diameter Terratec TBMs to be used on the 13.5km-long Río Subterráneo a Lomas tunnel for the Argentina national water and sanitation company AySA. The project will carry drinking water from the treatment plant in Bernal, in the Quilmes District, to the city of Lomas de Zamora.

President Fernández visits the construction site in Buenos Aires

The two 4.66m Terratec EPBMs for Italian contractor CMC di Ravenna, have been designed to work through the variable soft ground geology of the alignment, which ranges from silts to sandy silts, with some cobbles expected. The TBMs have high-torque soft ground cutterheads of the spoke style and with a 49% opening ratio. Cutting tools consist of fixed and back-loading knife bits that will require minimum interventions for maintenance.

First of twin TBMs for the project

At an average depth of 25m, the first drive will begin with a 400m radius curve and continuing on a straight alignment with a maximum gradient of +/- 2.0%. The precast segmental lining promises rings of six 250mm thick x 1.4m wide segments, four parallelograms and two keys.

The new Agua Sur water supply system comprises a series of major infrastructure works that include a raw water intake; 23km of water conveyance infrastructure, built in two stages; two pump stations; 46km of pipe connections; and expansion of the General Belgrano water treatment plant to increase its water production capacity from a current 1,950,000m³/day to 2,950,000m³/day. The project is expected to take about 10 years to complete.