Gothenburg, Sweden’s industrial heart and its second-largest city, has seen a significant increase in traffic congestion over the last decade. The changes in traffic patterns are related to the shift in industrial activity from the city center to new areas, but also because former industrial lands in the city center have been reborn as popular residential and commercial areas. With the objective of reducing the traffic congestion and supporting the new city center demographics, Swedish transport authorities made plans for a road tunnel and a new railway bridge across the Göta Älv river.
Creating a submersed-tunnel when crossing under the river will preserve good access for ships passing along the river and keep Gothenburg’s port competitive in the future. 100-metre concrete tube elements were built in a dry-dock on shore and then floated out into the river and submerged into a deep trench dug into the soft clay of the river bed. Golder supported the tunnel project with geotechnical design including slope stability analysis for dredging the trench and the surrounding quays. Geotechnical support was also provided for temporary construction on land, and design for soil stabilization with lime cement columns for the excavation of a deep trough on one of the connection ramps down to the tunnel. Golder also designed the warping piles and winch points that were instrumental in successfully pulling the concrete tunnel elements down to the bottom of the trench.
Golder supported the second aspect of Gothenburg’s transportation improvements too – an opening, lift-swing bridge with a span of 1.5 km railway bridge built across the river to improve the passenger and freight service. Golder, through its instrumentation and monitoring subsidiary Geometrik, was contracted to install measurement equipment and monitor the new railway bridge’s pilings and other elements, as well as surrounding soil movement and pore pressure. This work was critical to meet overall project safety requirements and to support a successful outcome.
The new “Marieholm” railway bridge opened for traffic in 2016 and the road tunnel is expected to be opened in 2020. The Marieholm Connection Project will significantly increase traffic capacity towards the Port of Gothenburg and the industries at Hisingen.
Photo courtesy of the Swedish Transport Administration.