Customer

Bristol City Council

Application

Pedestrian Footbridge

Customer Problem

St Anne’s Pedestrian Footbridge is a historic structure built in 1957 to cross the River Avon. Constructed in steel with a concrete and timber decking walkway, the historic bridge was in need of significant repairs following a review of the structure by Engineers at Bristol City Council. Not only was the walkway decking surface in need of repair, but the entire steel structure was showing significant signs of corrosion.

The council decided that to prolong the life of the bridge, the structure of the main span and access ramps should be converted from steel and concrete to a lighter weight and longer lasting Glass Reinforced Polyester (GRP) construction. As a consequence, Polydeck Limited was called in to assess the possible alternatives.

Polydeck Solution

  • Polydeck Limited proposed the use of its 12mm thick GRP anti slip panels to be mechanically fixed to a series of pultruded C section beams which would replace the corroded steel support beams. The Pultruded GRP beams were fixed at 400mm centres to the original longitudinally running inner steel beams and designed to take a loading of 5kN per square metre.
  • Following removal of the original decking and after months of painstaking remedial work to the steel structure, the Polydeck panels were fitted. Following installation, Engineers at the council confirmed that the Polydeck system had lightened the bridge dead weight by in excess of 30 tonnes, thereby significantly reducing the stress on the overall structure.
  • The council specified that the Polydeck panels should be supplied in a grey colour with a diamond pattern to match the distinctive design of the bridge.