By Lynda Myer
As the longest immersed tunnel in the world, the Fehmarnbelt Tunnel will be18 kilometers long and it is considered one of the largest infrastructure construction sites in Europe. While a formwork concept has been developed for this central production of the standard tunnel elements by PERI SE, with the unloading of the last of the twelve ships required, the delivery of the customized special formwork from the central formwork supplier for this project was completed with a volume of more than 10,000 tones.
With 217.00 m long and 73,000 tones weight, 79 standard tunnel elements’ formwork material is being provided by PERI SE. Additionally, each of the total of 79 standard elements is composed of nine concreting sections with a width of 45.00 m and a height of 9.00 m. Per concreting section Almost 3,000 m3 of concrete are used, resulting in a weight of over than 8,000 tones each.
Following the concreting process, the elements are fitted with bulkheads at both ends and sealed tightly and then the basin containing the elements is flooded with water. Thanks to the tight seal, the elements float and can be transported to the location in the Fehmarnbelt, where they are immersed in the tunnel trench and connected so they are watertight.
Decreasing the risk of water penetration during tunnel operation, the solution developed by PERI SE forms the foundation for monolithic concreting. Also considering that a tunnel section is concreted without ties in the outer walls, this approach means remarkable savings in material and labour costs, thereby reducing the use of raw materials. Poland, Italy and the PERI SE plant in Weissenhorn, Germany, were the locations of producing the special steel components of the PERI SE formwork solution. Planning and execution of the delivery of the entire material with a total of twelve ships and over 250 trucks in accordance with requirements and deadlines were a key factor for on-time completion of the construction project and were made possible through close coordination between the client and PERI. At the end of February 2023, PERI SE already celebrated the delivery of the one millionth part to the construction site of the Fehmarnbelt Tunnel project in Denmark.
Linking Denmark and Germany for road and rail traffic, the Fehmarnbelt Tunnel is going to cut travel time to seven minutes by train, and ten minutes by car, that makes this construction project an important contribution to environmentally-friendly transport and providing a fast rail connection between Scandinavia and Central Europe.
Including total of five tunnel tubes, this immersed tunnel has a whole width of 45.00 meters, and two of its tunnels are two-lane tubes for motor vehicles, whereas two are single-lane tubes for rail traffic and one is a service and escape tube.
