A bridge for the next 100 years

It has been ten years since serious damage was discovered on the Rader High Bridge, which opened in 1972. In view of the massive increase in traffic - 63,000 vehicles a day are expected on this section of road by 2035 - the old bridge with two lanes in each direction is to be replaced by two new bridges by 2030. These will each have three lanes in each direction and a hard shoulder.

Since DEGES awarded the contract for the first of the two bridges in December 2022, all parties involved have been working hard to achieve the ambitious target of completion by November 30, 2026. Despite an extremely tight preparation and planning period, the first work began shortly after the contract was awarded - an achievement that was only possible thanks to the close partnership between the client and the inspector.

Innovative idea shortens execution time

The hydraulic engineering site in Lake Borgstedt, a branch of the Kiel Canal, presents particular challenges. Here, three piers have to be erected in the water, which requires the installation of 40-meter-deep bored piles from the water. Thanks to an innovative proposal from the Implenia team, the construction time can be reduced by using fewer and larger bored piles per pier.

The poor subsoil poses a further challenge, as load-bearing sands are only available in deeper layers. In the water and in the area of the mudslide, 31-metre-long cladding pipes with internal reinforcement are therefore inserted into the ground. Total weight of the bored pile reinforcement: around 22 tons.

Logistically challenging hydraulic engineering site

Implenia is providing all the water logistics for the work on the hydraulic construction site, including a construction site ferry, a push boat and various pontoons, barges and two jack-up platforms, which have a deck load of 250 and 400 tons respectively. The technical coordination and equipment of the jack-up platforms required intensive work preparation. The jack-up platforms were equipped with modular legs to enable them to pass over high-voltage power lines with a maximum clearance height of 23 meters. Numerous feasibility studies were carried out to optimize the configuration of the cranes, the logistics plans with the watercraft and the mooring options. Detailed deck plans for each jack-up platform ensure stability during floating and working conditions and provide the basis for the smooth operation of the heavy-duty machines.