Osnabrück
General contractor for rebuilding the Düte Bridge
Osnabrück, Germany / 07.2016 - 03.2022
Between the Lotte/Osnabrück motorway junction and the Osnabrück-Hafen slip road, the Düte spans one of Germany’s most important north-south links. As part of the refurbishment of the A1 motorway, the existing Düte Bridge was replaced with a new structure. Over a period of five and a half years, a new bridge structure using a composite steel construction method was built. PORR structural engineering, based in Düsseldorf, was responsible for the construction of the replacement bridge. PORR special civil engineering carried out the pile foundation work using cast-in-place concrete driven piles, whilst PORR transport route engineering carried out the roadworks.
Facts & Figures
Company
PORR Ingenieurbau
Type
Bridge construction
Runtime
07.2016 - 03.2022
Composite steel construction for the new bridge
Building a new bridge whilst traffic continues to flow
The dismantling of the existing bridge presented particular challenges. The structure, dating from the 1970s, featured a shared superstructure for both directions of traffic. This meant that it was initially not possible to dismantle individual halves of the bridge in stages. In preparation for the new bridge, the existing deck was split lengthways over a length of around 300 metres. The prestressed concrete deck, up to 65 cm thick, was cut through using concrete saws. Once split, traffic was able to continue on one half of the bridge whilst the opposite side was demolished and rebuilt.
Support structure between the river, railway and road
Before dismantling could begin, the existing bridge had to be provided with additional support. To this end, a support structure weighing around 2,150 tonnes was erected beneath the bridge. The support structure spanned not only the Düte, but also an ICE railway line and a local road. A total of 479 hydraulic presses were used to position the structure beneath the existing bridge. The substructure formed the basis for the subsequent demolition work on the existing bridge.
Pile foundations for the new bridge
In parallel with the construction of the new bridge, PORR special civil engineering installed the deep foundations using cast-in-place concrete driven piles. The foundations form the basis for the new piers and abutments and transfer the loads from the structure into load-bearing soil layers. This created the conditions for the subsequent construction of the piers and the superstructure.
Building between a transport corridor and a river landscape
The works took place in an area where road traffic, rail traffic and the river environment converge directly. At the same time, the construction works were carried out within a sensitive floodplain area along the Düte. Once the construction works were completed, measures were taken to re-shape the course of the river. Today, the Düte flows in meandering sections beneath the structure and continues to characterise the landscape beneath the bridge.
The basis for the new crossing
Even before traffic could be channelled over the new bridge, foundations, piers and superstructures were erected step by step along the route. The replacement of the Düte Bridge created a new section of the A1 motorway between Osnabrück and the Münsterland region. A new crossing over the Düte was thus created between the river landscape, the railway line and the motorway.
