It has been announced by TERRATEC that the first of two 4.66-m diameter EPBMs (Earth Pressure Balance Tunnel Boring Machines) that is going to be used to excavate the Río Subterráneo a Lomas tunnel is currently being assembled, in Buenos Aires, Argentina.
For marking the commencement of the project, a cutter head lowering ceremony was held in the presence of Alberto Fernández, Argentina’s President, as well as numerous government officials and representatives from AySA, Argentina’s national water and sanitation company, and CMC di Ravenna, the Italian tunnel contractor.
The tunnel is an essential component of the multi-billion-dollar Agua Sur system which is currently being built by AySA. The new system is the country’s largest water infrastructure project in 40 years and will supply access to fresh water for 2.5 million residents in the southern metropolitan area of Buenos Aires.
Besides its sister machine, the 4.66 m diameter TERRATEC EPBM named ‘Eva’ will be placed by CMC di Ravenna on the 13.5 km long tunnel, which will ultimately 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 TERRATEC has designed the EPBMs to afford the variable soft ground geology along the project alignment, which ranges from silts to sandy silts with some cobbles expected. The TBMs’ high-torque soft ground cutterheads feature with a spoke style design, a 49% opening ratio, and cutting tools including fixed and back-loading knife bits that will guarantee rapid advancement and minimum interventions.
The depth of the tunnel which is going to be excavated is averagely 25m, beginning with an approximately 400-m radius curve and continuing along an essentially straight alignment, reaching a max slope of +/- 2.0%. As the machines development, they will set a precast concrete lining ring including six segments (four parallelograms and two keys) 250 mm thick, 1,400 mm wide, segments.
The new Agua Sur System contains a series of major infrastructure works that consist of a raw water intake, the expansion of the General Belgrano Water Treatment Plant – which will raise its water production capacity from a current maximum of 1,950,000 m3 per day to 2,950,000 m3 per day – 23 km of water conveyance tunnel which is built in two stages, two pump stations and 46 km of pipe connections. It is expected to have the project totally completed near 10 years.
For more information visit: www.terratec.co
Source: Tunnel Business Magazine