Civil & Industry

Darmstadt | Germany

After the Rheinbrücke contract, we are building another bridge structure in Germany: at the intersection of the A5 and A67 motorways at the Darmstädter Kreuz. This traffic artery between Mannheim and Frankfurt is in need of renovation. Eiffage received the honour of the refurbishment and is demonstrating its expertise in various fields: general contractor Eiffage Infra-Bau for the concrete construction, Iemants for the steel bridge(s).


From Süd to Nord

The current traffic junction will get a complete makeover. The existing complex with 4 bridges will be demolished and replaced. There will also be more lanes than before. The works are carried out in phases as follows:

* Südrampe: southern ramp (entrance and exit)
* Nordrampe: northern ramp (entrance and exit)
* Substructure Nord of the Zentralbauwerk (ZBW)
* Substructure Süd of the Zentralbauwerk (ZBW)


The northern ramp takes the A67 - with 2 lanes and 4 spans - from south to north across the A5. The current structure from 1966 has a total length of 138 m and will be replaced by a steel structure with three walk-on box girders - a total of 170 m with room for an exit lane for trucks.


The southern ramp has a length of 138 m, also has 4 spans and dates from 1967. The new Süd gets 3 steel box girders and is reduced to 94 m. The old ZBW consists of 2 substructures, each with a construction length of 122.5 m and 4 spans. The new ZBW will have three spans over a length of 160 m.


Technically unique process

Project manager Yves Boenders: “The implementation is based on the plans provided by our customer and the selected engineering firms. For steel construction and painting, there is an interaction between our offices in Arendonk, Balen, Poland, Tessenderlo and Hoboken. Larger pieces go from Balen by water to Mannheim, from where they are then transported by road to Darmstadt.”


The construction of the components themselves takes place on a pre-location with a pre-foundation in the same line of the 'Taktkellers’ bridge. This is technically unique and it allows us to slide the bridge into its final position. For the Nordrampe, for example, we work in 3 ‘Takten’: the pieces are made half and are then slid into position. By making preparations in the Taktkellers, we avoid blocking the busy motorway for too long.


Sliding the bridges is one of the biggest challenges and requires sufficient support while moving. For this purpose, we have developed custom-made sliding shoes with rubber bearings, load distribution plates and a sliding surface made of polished stainless steel and polytetrafluoroethylene (PFTE). In this way, we imitate a spring in balance - not too tight, not too loose.


Undulating bridge with colours

And the looks? We see a modern bridge complex under construction, according to the highest German standards. The unusual geometry of an undulating trough bridge, although with colour detail, is striking. The inside of the ZBW gets strips in all shades, from green to purple.


Is this different from the other bridges we have already built? All our bridges meet the highest requirements and applicable standards. That means top quality and reliability, taking into account all customer requirements. In that respect, the colour palette is certainly special and the bridge is custom-made in its purest form.


On track

“We started the Südrampe in March 2021. The Nordrampe and ZBW Nord are planned for July 2022, with the start for ZBW Süd planned for spring 2023. First, ZBW Nord must be put into service to divert traffic. After that, we can demolish the existing bridge. We are on schedule and lessons learned along the way help us, for example, to optimise welding details and processes. With our passion for steel, our technical critical eye and our focus on solutions, we are working towards perfection”, concludes Project Manager Yves Boenders.