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 optimise 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 organisation of the multi located design team will be discussed.