According to the environmental atlas of Buenos Aires, precipitations have tripled between 1980 and 2010 compared to the period between 1900 and 1930. In addition, heavy rainfalls within shorter periods impede direct drainage of the water. For this reason, the city launched the construction of the second flood discharge tunnel in August 2016. Besides the launching shaft with a diameter of 35 m and a depth of 25 m, the project includes a tunnel with an overall length of 8.4 km where a 5.9 km long section is excavated with a Herrenknecht EPB Shield (diameter 6,070 mm) and lined with concrete segments (inner diameter 5,300 mm).
The Consortium Roggio – Cartellone - Supercemento produces the concrete lining segments on a carousel system from Herrenknecht Formwork including 48 moulds, reinforcement supply, concreting station as well as curing tunnel with steam generator. Customized segment handling equipment supplied by Herrenknecht Formwork enables the logistic processes to work perfectly. With this installation, the team exceeded the requirements by producing up to 70 segments in 10 hours.
According to Project Engineer Agustín Guastavino the most important factors for a successful segment production are a good ring design, a high quality of the moulds, a suitable concrete mix as well as good labour. Although the team in Buenos Aires has little experience with tunnel lining segments so far, the production runs smoothly. Having already produced 24,000 segments, the Consortium almost achieved their goal. „The experts of Herrenknecht Formwork realized the design of the segment factory with great commitment according to our needs“ says Guastavino. We thank the team for the good cooperation and wish them a successful completion of the project.
25,000 tunnel lining segments are currently being produced in the city of Buenos Aires. Upon completion of the works, more than 300,000 people will take advantage of this: The second flood discharge tunnel for the Vega River, which is crossing the metropolis from west to east, will double the discharge capacity and thus reducing the risk for floods considerably.