The High Level Footbridge is the centrepiece of Sunderland City Council’s Riverside regeneration programme. The 250m-long by 10m-wide steel and precast deck composite bridge requires two huge pillars, the construction of which presented a complex challenge due to constrained site access down the steep riverbanks, a historic wall on the south bank, and riverbed contaminants.
These constraints eliminated traditional solutions, such as a stone ramp and piling platform. Site investigations proved that the historic wall would be unable to withstand any loading. Working from the river was not possible as contaminants would have been disturbed by the jack-up barge’s spud legs.
During the Pre-Construction Services Agreement (PCSA) stage, we brought together a collaborative team of permanent and temporary works designers, piling specialists, suppliers and the client to assess innovative options. We pivoted from traditional design approaches to one where temporary works and construction methodologies informed permanent design decisions.
The outcome was a unique cantilevered piling structure that enabled construction in the constrained environment without impacting the historical wall, avoided extensive and unviable earthworks, and allowed a smaller working footprint, reducing environmental impacts.
Three Winning Facts:
- Exemplar use of PCSA stage to de-risk the project and identify innovations.
- Pioneering engineering solution that has allowed the piers to be constructed in the preferred location and in time for the scheduled bridge superstructure’s Summer 2024 arrival.
- Broad industry relevance, with lessons already shared across VolkerWessels and social media, and plans to publicise in the trade press, e.g. New Civil Engineer
