FCC Construcción

To improve mobility conditions in the southern zone of the web of cities and towns surrounding Madrid, which is home to a population of close to one million, the Community of Madrid decided to create a new infrastructure to improve appreciably the amount of public transport on offer, for connections inside and between outlying cities as well as for radial travel to Madrid itself.

Metrosur is like a circular underground line that runs through five cities south of Madrid. The route has numerous stops inside each city, so the system can operate as each city's own internal underground. The ring created by Metrosur is connected to the rest of the Madrid Metro network by the extension of line 10 to the new station of Alcorcón-1, where passengers can transfer from one line to the other.

FCC Construcción executed Metrosur Contract Number 2, which covered sections II and III, a total of 7,312 metres, running through the cities of Móstoles and Fuenlabrada and accounting for approximately 20% of all of Metrosur.

This job began at the entrance to the Móstoles 1 station and ended in the vicinity of the Fuenlabrada 1 station. It comprises five stations, four of them having been built between retaining walls, while the fifth station, Móstoles 5, was built on top of foundations laid after the site pit had been dug out.

The execution of the line followed this sequence: from Móstoles 1 station to Móstoles 5 station, a total of 3,959 metres, a TBM was used; 2,576 metres were built on a cut-and-cover basis, of which 450 metres were done with retaining walls and 2,126 metres were run through a cut-and-cover tunnel. The tunnel has an inner diameter of 8.34 metres and is lined with concrete with seven segments per ring.

During the building of the tunnel with La Adelantada, a latest-generation pressurised-shield tunnel-boring machine belonging to FCC Construcción, the world record for large-diameter concrete-lined tunnels was broken by building 1,020 metres of the tunnel in one month.