Fehmarnbelt tunnel
Germany / Denmark
Doka designs the gateways to the Fehmarnbelt tunnel
The Fehmarnbelt Fixed Link is an important element in the green transitition for the European transport sector. Realised by the general contractor FLC (Femern Link Contractors), the project involves the construction of an 18 km immersed tunnel between Rødbyhavn on Lolland in Denmark and Puttgarden on Fehmarn in Germany. The tunnel will create an efficient, green transport corridor connecting Scandinavia with the rest of Europe. Once completed, it will be the world’s longest immersed tunnel for cars and trains and is scheduled to open in 2029. Construction is taking place both on land and underwater.
The Doka team is responsible for the formwork planning and work for the tunnel portals and ramps on both the German and Danish sides. The Fehmarnbelt Tunnel will feature a two-lane motorway in each direction and a double-track railway line for electric trains upon completion. Additionally, it will include a maintenance gallery.
600 m Tunnel portal in Puttgarden and 260 m Tunnel portal in Rødbyhavn, each with 5 tubes, implemented with the Heavy-duty supporting system SL-1, Large-area formwork Top 50 & Framed Formwork Framax Xlife.
The two tunnel portals are being constructed in the segmented cut-and-cover construction method. In this process, the 20-meter-long tunnel segments fit together like puzzle pieces using five tunnel formwork travellers consisting of the Heavy-duty supporting system SL-1. First, the base slab for the four tunnel tubes and the maintenance gallery is poured, followed by the construction of the advancing walls. Finally, the slab is completed.
Type of building
Tunnel portals and ramps
Challenge
- A 3D designed formwork concept for the simultaneous construction of all tubes, including the very narrow (2m wide) maintenance gallery
- Very high safety standards, such as interlocking tunnel segments and ventilation niches inclined in all directions for the subsequent installation of fans
- Transition segment for the connection from land to water, featuring an integrated steel frame across all 5 tubes
Solution
- The entire formwork planning was carried out in 3D, and thanks to BIM-supported control, all solutions were implemented precisely and without collitions. A total of five movable tunnel formwork travellers, based on the Heavy-duty supporting system SL-1, including one monoleg formwork traveller, erected the 20m long segments.
- In the Doka Pre-assembly service, pre-assembled, reusable formwork boxes with a so-called 'Shear Key' ensure precise interlocking of the individual segments and guarantee the highest safety. The execution of the formwork boxes, which are inclined in all directions for the ventilation niches, is facilitated by 3D visualization.
- The steel frame is fully integrated into the formwork solution, requiring the highest precision to meet the required tolerances. Additionally, the controlled transfer of the increased concrete pressures presents another challenge.
In this exceptional formwork application, Doka was able to add value with additional services
The experienced Doka's pre-assembly on-site handles the safe and professional assembly of the entire formwork material in Puttgarden on Fehmarn. On the Danish side, Doka Formwork Instructors oversee the correct installation of the formwork solutions provided by Doka. This involved managing 1,400 tons of formwork material for five SL-1 tunnel formwork travellers, including one Monoleg formwork traveller, as well as formwork for ramp walls, various structures, and land-based construction work on both sides. In Doka's pre-assembly service, pre-assembled formwork units and customized special solutions ensure the highest precision and a safe, cost-optimized construction progress.
Andreas Zitzenbacher | Head of Large Scale Project Management
"For a project of this scale, which crosses national borders, professional project management is crucial for a solution-oriented and constructive collaboration. This is the only way we can support our customers as a reliable partner and successfully achieve our common goal - Northern Europe's largest infrastructure project."
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Project data
Year of completion
2029
Project duration
2023-2029
Country
Germany / Denmark
Contractors
Femern Link Contractors (FLC) consists of VINCI Constructions Grands Projets (France), Aarsleff (Denmark), Max Bögl Stiftung & CO KG (Germany), BAM Infra B.V (Holland), BAM International B.V (Holland), Wayss & Freytag Ingenieurbau AG (Germany), Solétanche-Bachy International S.A.S (France), CFE SA (Belgium), Dredging International NV (Belgium).
Building data
Construction method
Segmented cut-and-cover construction method
Section length
20m
Construction element
Tunnel portals and ramps
Total length
600 m tunnel portal in Puttgarden, 260m tunnel portal in Rødbyhavn