Design & Construction of the Hull River Defences

The Hull River Defences (HRD) is a £65M project comprising new interventions to protect Hull from flooding where existing river defences are at risk of failure within the next 10 years. The new structures include tied and anchored sheet piled walls as well as 12 cantilever combi walls. The total plan length of piled walls is approximately 2km and pile lengths are up to 19m.

This paper will explain the design methodology where there is incentive to start construction at the earliest opportunity despite the need to carry out many surveys to feed into the design. Key aspects of the design include the reduction of cost and carbon by early comparison of tubular and high modulus pile designs, advanced ground investigation methods to directly assess soil stiffness, and use of finite element analysis to supplement traditional soil-structure interaction.

Geotechnical Feedback from the construction includes an evaluation of the benefits and challenges of raking piled walls and documentation of observed ground movements, back-analysis and implementation of contingency plans during installation of piles from behind a fragile oldg ravity wall.