Work begins on metro expansion in Vienna
A consortium of Austria’s two largest construction companies, STRABAG and PORR, has won the tender for the first phase of the largest connected construction project of Wiener Linien, the Vienna public transport provider.
A total of 7 km of tunnel will be driven and four new stations built as part of the redirection of the U2 line. The contract value for the consortium – in which each party has 50% – is around half a billion euros. Construction is set to begin in February 2021 and will run until mid-2028.
“Construction work in the inner-city is always a challenge in light of the cramped conditions. Drilling beside the facades of the nearby buildings requires a great deal of expertise and transport to and from the sites through the narrow alleyways surrounding Neubaugasse is exceptionally complex in terms of logistics”, says Thomas Birtel, CEO of STRABAG SE.
Significant upgrade to public transport coverage
The expansion of the inner-city metro network network is a huge milestone in Vienna’s urban development. Enhanced performance, direct links for travellers, and significant benefits for the environment all characterise the Wiener Linien’s most important future-focused project.
“This key infrastructure project definitively closes the gaps in the inner-city metro network for Vienna. With our decades of experience and exceptional technology knowhow in underground railway construction, we will play a key role in sustainably improving Vienna’s public transport infrastructure”, says Karl-Heinz Strauss, CEO of PORR.
Under the metro expansion, the U2 line between Karlsplatz and Rathaus will become part of the U5, while the U2 will branch down towards the south of the city. The contract is part of the first construction phase of the U2/U5 line expansion in the Austrian capital. This includes the phases U2/17-21 (U2/17 driven by TBM, U2/18 Matzleinsdorferplatz station, U2/19 Reinprechtsdorfer Straße station, U2/20 Pilgramgasse station and U2/21 Neubaugasse station).
Tunnelling team to work around the clock
The demanding construction of the two tunnels in the inner-city area will require the tunnelling team to work around the clock in shifts. Around 4 km will be driven by a tunnel boring machine (TBM), while another 3 km will be bored using the New Austrian Tunnelling Method (NATM). All of the works such as tunnelling, structural engineering, ground engineering and railway construction will be rendered autonomously by the consortium.
The stations are being built using the cut-and-cover method of construction, with the station shafts up to 40 m wide and 50 m long. This means that the excavation for the stations, which lie at a depth of up to 40 m, must first be secured by means of drilled piles and internal steel stiffeners and then worked downwards floor by floor. The station shafts themselves are also the central hub for the delivery and removal of the material.