SAG1_3

HOCHTIEF demolished and replaced four road-over-rail bridges in central London as part of TfL’s Structures and Tunnels Investment Portfolio (STIP). Ardleigh Green Bridge carries the four lanes of the A127 Southend arterial road over the East Anglia Railway.

Key features:

  • Road-over-rail bridge deck demolition and construction
  • Service bridge
  • Complex utilities diversions
  • Traffic Management
  • Phased reconstruction

To reduce lane closures and minimise congestion on this major route in and out of London, we optimised our construction sequence to complete the replacement in two phases.

During phase one, we demolished the eastern side of the bridge during a three-day closure of the A127. We set up a contra-flow arrangement on the remaining half of the bridge to keep the road open to traffic while we rebuilt the eastern side. We prefabricated the eastern bridge deck offline and launched it across the railway during another short road closure, reducing construction time on site and our impact on the road network. Once the eastern section was complete, we moved the contraflow onto it to enable us to start phase 2: the demolition and replacement of the western side following the same method. The final works to complete the phase 3 demolition of the remaining support piers to the old structure were completed over Christmas 2020.

Our phased approach has enabled us to keep the A127 open to traffic in both directions throughout construction, only closing it temporarily for the key demolition and bridge launch works.

We won a Considerate Constructors Performance Beyond Compliance award and were shortlisted for a British Construction Industry Award in the Temporary Works Initiative of the Year: Civil Engineering category. All four lanes of traffic reopened in 2019.