At around 1,805 metres in length, the Lueg Bridge is the longest bridge in Austria. It forms part of the ASFINAG road network and is regarded as one of the most complex buildings on the A13 Brenner motorway.
The Lueg Bridge is situated between the Obernberg Valley Crossing and the Brenner North junction. It is a slope bridge and is founded in a landslide area at its southern end. The bridge consists of six structural sections, which are designed as prestressed concrete structures or composite steel structures. The carriageways in both directions rest on a single structure. As the existing bridge has reached the end of its service life, a new bridge is currently being constructed in extremely steep and rugged terrain, under extremely difficult and confined conditions. The old slope-supported bridge is being demolished and replaced by two separate structures. Five new structures in composite construction are being built for each carriageway. Sub-structures 1 to 4, with a standard span of approx. 36 m, are being constructed as continuous double-web T-beams, consisting of tightly welded orthotropic steel decks and a reinforced concrete deck. Sub-structure 5 will in future span the landslide area with two single-span structures, each over 100 m long, constructed using composite construction. The new bridge will improve road safety and accessibility, as it will be bi-directional and have two separate carriageways. This will allow traffic to be channelled over two lanes in each direction during maintenance work. Construction work on the new Innsbruck-bound carriageway, which is being built on the valley side of the existing slope bridge, is currently in full swing across various sections. The construction of the new bridge piers is already well advanced. Work has also begun on the north abutment side on the erection of the tightly welded steel box girders, which form the cross section of the new composite bridge. The girder sections, which were manufactured at the factory and delivered to site, are being hoisted in sections using a mobile crane, fine-tuned and welded together at the joints. Following on from this, and precisely timed, the formwork carriage for the construction of the in-situ concrete deck slab is already being assembled. In close consultation with ASFINAG, as well as with the contractors and the respective specialist planners, the BERNARD Gruppe is providing on-site construction supervision services in a joint venture with ZETCON. In addition, the BERNARD Gruppe is also responsible for quality control of the steel construction, both during the factory production of the steel box girders and during the steelwork construction on the construction site.
Albert Außerlechner, BERNARD Gruppe
