Züblin Scandinavia AB, a Swedish subsidiary of STRABAG SE, has been awarded as leader and main shareholder in joint venture the design & build contract for the Marieholmstunnel project, a 500m long immersed tunnel consisting of 30m wide x 10m high elements, that passes under the river Göta älv in the city of Gothenburg. The contract agreement, which also comprises the mechanical and electrical works and which has a total contract value of about €170M, was signed on 4 June 2014. Owner of the project is the Swedish road and railway authority Trafikverket, to which the tunnel is to be handed over in October 2020.
Marieholmstunnel is a road tunnel consisting of three lanes in either direction with a service tunnel in the centre and a designed lifetime of 120 years. Züblin will construct three tunnel elements of 100 m in length each on site in a drydock and immerse them at their final location in a trench dredged into the river bed. On either side of the immersed tunnel section, cut & cover tunnels will be built in deep excavation pits continuing in ramp and trough sections. Special consideration will be given to the environment, e. g. the flora and fauna of the river Göta älv, during all phases of construction. The installation of all mechanical and electrical systems also forms part of the contract, which includes an option to operate and maintain the tunnel for five years after completion.
The project will start just after the handover of Trafikverket’s Söderströmstunnel in Stockholm, a project of similar size and complexity executed by Züblin also as an immersed tunnel.