Securing the Luegbrücke bridge

Measuring 1,804m in length, the Luegbrücke is the longest bridge on the Brenner motorway. Having been built between 1966 and 1968, it is also one of the oldest. Sadly, it is now in a state of disrepair. The components at the four main structural joints in particular already present a safety risk. Before commissioning a new replacement building, it was therefore absolutely essential to realise an additional support structure to ensure traffic safety.

A formidable task.

The structural support erected by PORR at the four critical points essentially consists of steel stanchions topped by trusses below the existing Luegbrücke bridge. If the bridge fails, its dead load and the entire carrying capacity will be transferred to the support structures. This corresponds to a mass of 1,300 tonnes or roughly 215 elephants per span of the existing prestressed concrete bridge.

A technical tour de force.

The challenging subsoil conditions and its location in steep, rocky terrain make the Luegbrücke bridge the most complicated load-bearing structure on the Brenner motorway. This was a job for our experts’ pioneering spirit.

The goal was to carry out most of the work from above. Work was only to be conducted from below if this was absolutely unavoidable. The 8.5m high and 35m long trusses were delivered and parked on the motorway in an upright position by special transport. This work had to be carried out with the utmost precision at precisely measured points to avoid overloading the bridge’s support structure. Two mobile cranes were then used to place the trusses on steel stanchions and transverse slides under the bridge in a tandem lift. The trusses were then positioned under the four main girders of the existing bridge and braced. Absolute precision was required until the beams were securely attached. To the best of our knowledge, this was the first time that this type of construction has been carried out in this way. This project is another example of PORR demonstrating its willingness to take on new challenges and find innovative solutions with perfectly coordinated teams.