Filstal railway overpass, Mühlhausen im Täle
|Company||ARGE EÜ Filstal PORR/Max Bögl|
|Principal||Max Bögl Stiftung GmbH &Co. KG|
|Location||Mühlhausen im Täle - Germany|
|Runtime||12.2013 - 09.2023|
Crossing the Filstal Valley by ICE in 7 seconds
The new Wendlingen-Ulm line is an important section in the forthcoming high-speed network of Deutsche Bahn and, as part of the European high-speed network “Magistrale for Europe”, it will also be of international significance. Large parts of it run along the BAB 8 motorway. On the ascent to the Swabian Alb, it branches off from the winding course of the motorway and cuts through the mountain in the new Albaufstieg tunnels – the Bossler tunnel and the Steinbühl tunnel. The Munich branch of PORR Civil Engineering, as part of the Max Bögl/PORR EÜ Filstal consortium, built the Filstal bridge directly adjoining the exit portals of these tunnels. The new bridge is Germany’s third highest railway bridge and ranks among the most spectacular railway bridges in the country.
The concrete bridge spans the Filstal Valley at a height of up to 85m and crosses the BAB8, the L1200 state road and the Fils River, as well as a local road and several paths. As the tracks in the tunnels are 30m apart, two separate load-bearing structures were built – 485m long towards Ulm and 472m long towards Stuttgart. The superstructure is 8.40m wide and executed as a six-span prestressed concrete box girder. Narrow, Y-shaped piers minimise the visual impact on the landscape and give the new gateway to the upper Filstal Valley a light and elegant touch.
Tunnel – bridge – tunnel: an unusual combination
In addition to the planning and construction of the two railway overpasses, various ancillary structures such as portal hoods, engineering buildings, pumping stations, tanks for extinguishing water, staircases, retaining walls, emergency access drives, roads and paths were realised.
At peak times, there was a team of 200 people working to complete the carcass on schedule – with active support from PORR Polska and the Berlin branch. Teamwork and trust were the key to success. This engineering masterpiece would not have been possible without the trust and cooperation of everyone involved in the project.
It is impossible to imagine the complex design behind this light and graceful bridge, or the challenges involved in its construction, starting with access to the construction site in drinking water protection zones and on steep slopes. To avoid wear and maintenance costs caused by bridge bearings, the Filstal bridges were designed largely as semi-integral structures; the columns and box girder superstructure were connected to each other monolithically and without seams, and a semi-elastic system of spring lamellas was used to connect them to the abutments in front of the Bossler tunnel. The only place where the superstructure is still moveable is at the portal of the Steinbühl tunnel. Loads are transferred via a combination of piled raft foundations and shallow foundations; the northern abutments are additionally anchored back into the slope. The bridge itself was built with the aid of an 800-tonne overhead feed scaffold and steel auxiliary towers. The superstructure was shuttered, reinforced and concreted in 10 sections in each direction and in the final stage, the superstructure and pier struts were friction-locked together.
The Filstal Bridge is located on the new Wendlingen-Ulm line, a section of the major Stuttgart21 project.© ARGE EÜ Filstal, Fotograf Tobias Steigerwald