Second Terratec TBM delivered to Rio Subterraneo a Lomas

14 August 2019

Argentina – The second of two new 4.66m diameter Terratec EPBMs has been delivered for a 13.5km potable water tunnel system, in Buenos Aires. Factory acceptance for the TBM, which was manufactured for the Río Subterráneo a Lomas tunnel, took place in July.

The machine will be deployed by Italian contractor CMC di Ravenna on a 13.5km-long tunnel that will carry drinking water from the newly expanded General Belgrano Water Treatment Plant, in the city of Bernal (Quilmes district), to the city of Lomas de Zamora.

The tunnel will be excavated at an average depth of 25m, beginning with an approximately 400m radius curve and continuing along an essentially straight alignment, reaching a maximum slope of +/- 2.0%. As the machines progress, they will install a precast concrete segmental lining ring consisting of six (four parallelograms and two keys) 250mm thick, 1400mm wide, segments.

A spokesperson for the manufacturer said of the machines, “The 4.66m diameter Terratec EPBMs have been designed to tackle the variable soft ground geology along the project alignment, which ranges from silts to sandy silts with some cobbles expected. The high-torque soft ground cutterheads feature a spoke style design with a 49% opening ratio and cutting tools consisting of fixed and back-loading knife bits to ensure rapid advancement and minimum interventions.”

The tunnel is a key component of the Agua Sur system that is currently being built by Argentina’s national water and sanitation company AySA. Financed by the Government and the Development Bank of Latin America (CAF), it is the country’s largest water infrastructure project in 40 years and will provide access to fresh water for 2.5 million inhabitants in the southern metropolitan area of Buenos Aires.