Abb_2

On the Abbey Bridge and Viaduct Replacement scheme, HOCHTIEF built a new concrete arch bridge over the River Avon and a 250m long approach viaduct in a flood plain. We also widened the road over the bridge and improved the junctions leading up to it to increase capacity.  

Key features:

  • Concrete arch bridge
  • 250m viaduct
  • Carriageway widening
  • Cantilevered footpaths
  • Abutment refurbishment
  • Junction improvements
  • Road signals

To reduce road closures, we built the new bridge around the existing bridge so that vehicles could still use it during the construction period. We built the approach viaduct in stages, completing the concrete substructure while the existing bridge was still open, and we maintained pedestrian access by installing a temporary footbridge.

Building over the river and in a flood plain presented key challenges during construction. We consulted closely with the Environment Agency and were connected to their river level flood alarm model, which predicted when the river would spill onto the floodplain. We were also advised by the Avon Navigation Trust, who manage all activities on the river and helped us to develop an acceptable construction strategy. A floating temporary crash deck prevented debris entering the River Avon during abutment refurbishment, while our use of oil spill booms, leak-proof plant and water filtering during pumping operations mitigated the risk of contaminating the flood plain.

Our phased construction strategy and environmental mitigation measures ensured the successful completion of the new bridge.