2002 saw ACCIONA use the EPB TBM, with a record 12.09m bore, to perform works on this section of Metro Line 9. The works consisted of boring two tunnels, of 4.6km and 6.15km length, at great depth, between the different stations of the section.
Furthermore, ACCIONA carried out the extension of Barcelona Metro Line 5, involving 2.6 km of new route, three stations and a 300m-long train depot. Conventional tunnel excavation methods were used in all the underground works in Barcelona's complex urban environmen.
LINE 5
The scope of the project involved the implementation of the infrastructure, superstructure and electrification of the extension of line 5 of the underground railway in the city of Barcelona, from the previously existing Horta station to the new Vall d'Hebron station. The total length of the section is 2.47 km.
The project included the excavation of a 1.568 m long tunnel for a double-track line, the excavation of a 300 m long area to park trains (capacity for five tracks), the excavation of a tunnel for a train bypass and three stations, as well as their corresponding access.
Drilling of the main tunnel and the rest of the underground elements was carried out using the new Austrian method (NATM) by mechanical excavation (drilling and blasting) split into heading and upper bench excavation phases and the installation of a flexible support. The caverns for the construction of the stations were bored using drills and blasting.
The works included:
- Construction of a 1.67 km tunnel and three caverns, all excavated using the NATM.
- Due to the urban environment where the work is located, specific regulations on the generation of noise and dust during the work were respected. The location of the works in a predominantly urban and densely populated area made it necessary to analyse and forecast solutions for the road traffic, streets and supply services affected. Thus, temporary detours and the necessary negotiations were established with business owners to maintain services during the construction of main roads and other above-ground works.
- Several construction methodologies were used to carry out this project. The tunnel of the line was built by excavating the heading and bench. The stations were large caverns built using the side galleries and central pillar method. For the accesses, the deep vertical wells were executed with sheet piling, and inclined galleries and fortified enclosures have also been executed.
- Due to the complexity of the terrain, horizontal drilling was carried out in the tunnel on each of the excavation faces, and vertical drilling was carried out in each of the station lobbies and wells.