Superstructure work at lofty heights on ground-supported shoring
After the structural and shoring foundations were completed in the southern construction section, as well as the construction of the first bridge pier, the first construction section of the bridge superstructure began. A further three of a total of 27 construction sections are to follow by the middle of the year. The starting point was the southern bridge abutment, which had already been concreted last year. The distance between pillar 5 and pillar 4, the first pylon seen from the southern abutment, is 115 metres. In between, auxiliary piers for the temporary, ground-supported shoring were placed at intervals of around 30 metres.
Its erection is continuing in a northerly direction and the next milestone will be the construction of the first two pylon piers. In the end, the bridge will rest on a total of five piers, the middle three of which are pylons with a V-shaped widening. The superstructure will be designed as a haunched continuous girder and will be braced at each of the three centre piers with 5 stay cables. The bridge cross-section is a two-span slab girder in reinforced concrete and above the edge piers in prestressed concrete. Steel cross girders are arranged at intervals of approx. 4.30 metres for the carriageway slab. Heavy plates up to 140 mm thick are used to reinforce the webs in the area between the haunches.
An impressive achievement "Construction from a single source"
"Our main areas for the construction site facilities are located in the Neckar floodplains. At the same time, this is an area at risk of flooding, so we have to avoid any possible environmental impact at all costs. Extreme caution is also required when crossing two railway lines, the L 370 and the supra-regional Neckar cycle path," says project manager Thomas Bergner, explaining the challenges.
A wide range of service areas are demonstrating their capabilities in the construction of the "Neckar Valley Viaduct", which PORR was commissioned to build by the Karlsruhe Regional Council (RP). PORR Structural Engineering is responsible for the overall project, while Equipment Services is responsible for the provision of tower cranes, equipment, containers and media installations. PORR Steel and Systems Construction is responsible for the production, delivery and partial assembly of steel components for the bridge superstructure as well as the cable anchorages, while Special Civil Engineering is expected to start with the bored pile work for the shoring and structural foundations in autumn 2024 once the northern, second construction field has been handed over by the client. Specialised colleagues from Austria will take care of the dewatering and water treatment work.
