Description of the supporting structure
The superstructure of the Scherkonde Viaduct is a 14-span continuous girder bridge along its entire length.
It is a broad girder bridge in prestressed concrete with a construction depth of 2 metres at the spans. To take the support moments, the construction depth is increased at the supports by means of haunches to 3.50 metres. The superstructure is linked to the western abutment and the supports. The supports are wall slabs with a consistent thickness of 1.50 metres. In the transverse direction, the supports have a width of 5.50 metres at the head and a constant taper ratio of 1:40. The deformations of the supporting structure caused by temperature, creepage and shrinkage can be compensated by the flexibility of the supports in the longitudinal direction. As a result of the constraining forces in the system, the substructures cannot be connected to the superstructure monolithically in support axes 11 and 12 or at the eastern abutment in axis 13. Consequently, bearings that move longitudinally are used there. To take up the longitudinal forces, the abutment in axis 0 is a fixed point. At the opposite end of the structure in axis 13 there is an expansion joint that compensates for the deformations. The foundations of the abutments and supports were created in the shale with large-bore piles of up to around 19 metres in length.
Bridges of this size have so far only been built as integral structures. The static system selected represents something new thanks to its semi-integral supporting structure and opens up great scope for innovation in relation to the use of integral structures for Deutsche Bahn's viaducts. As a result of the reduced number of bearings, joints and costly inspection facilities compared with the usual prestressed concrete box girders, significantly lower maintenance costs are expected for this type of structure.