The design and construction of the £1.5 billion A14 Cambridge to Huntingdon Improvement scheme presented a range of geotechnical challenges. The scheme had a large earthworks deficit where some 4 million cubic metres of the 7.2 million cubic metres of fill material required had to be won from borrow pits along the route. Mostly the founding conditions were chalky glacial till and heavily over-consolidated clays with piled foundations for all major structures. This provided the opportunity to optimize pile design to reduce the out-turn cost of the project.

The presentation will give an overview of the scheme and will describe the main aspects of the design and construction of the earthworks, retaining structures and structure foundations, including detail of the pile design methodology and pile test methods developed.

The project was short listed for the 2018 Ground Engineering Geotechnical Team of the Year and the organization of the multi located design team will be discussed.

Paul Nowak is Technical Director, Infrastructure Geotechnics at Atkins and was the Geotechnical Team Lead for the A14 Cambridge to Huntingdon Improvement scheme. He has over 40 years’ experience in the design and construction of major infrastructure projects, particularly over the last 25 years as Design Lead on D&B and PPP Schemes.

Dean Maddison is Technical Director Ground Engineering at Jacobs and was one of the three Deputy Geotechnical Leads for the A14 scheme. He has 40 years’ experience of highway infrastructure projects, development on marginal land and the investigation and management of major landslides.