Haarbachtal viaduct at motorway A544 near Aachen requires renovation. The 157-metre-long composite bridge with a transversal and longitudinally prestressed concrete deck slab was built in 1956. Because of significant damages, the structure will be replaced by a new viaduct. The damages are so severe that vehicles could only pass the bridge on a single lane in the centre and couldn’t be used for site logistics during construction.
The dilapidated structure was demolished by controlled explosion on 30 January. The around 20-metre-high bridge stood on eight filled steel piles which were blasted in quick succession – collapsing around 2,900 tonnes of material in a controlled manner.
At the same location the new Haarbachtal viaduct will be built. To maximally reduce construction time, a functional tender was chosen during which suppliers could propose innovative methods to speed up construction time. In only 22 months, the viaduct should be operable again. The new structure consists of two superstructures, designed as steel composite bridge with trapezoidal cross section. Due to its wide projection, the deck slab is supported in transverse direction by double-T longitudinal girders which are connected to the main box of the structure by tension cords and compression diagonals.
The assembly of both steel superstructures is done by incremental launching from the Cologne side of the bridge. By using semi-prefabricated elements, which already lie on the steel during launching, the deck slab does not require a formwork thus allowing a fast construction progress, and ideally, the fast opening for traffic in direction Aachen.
SSF Ingenieure has been contracted by AMAND Bau NRW with the entire final design of the superstructures, substructures and pit sheeting constructions.