The design of integral bridges with bankseat, half-height and full-height abutments on the A14, UK

Abstract

The Highways England A14 Cambridge to Huntingdon Improvement Scheme consists of both online improvements to existing sections of the A14 and a new offline section constructed on a green field site bypassing Huntingdon, UK. The scheme includes the design and construction of 22 integral bridges in varying forms typically found across the wider highway network. This paper outlines the different structural forms used on the A14 including ‘bankseat’ abutments on discrete columns, half-height abutments on a single row of piles and full-height abutments. The design challenges encountered for each type of structure are discussed, including the methods of modelling adopted for the soil–structure interaction. Primarily, it will highlight areas where the current codes of practice and design guidance (such as ‘PD 6694-1:2011: Recommendations for the design of structures subject to traffic loading to BS EN 1997 1:2004’) could be developed to reflect the specific requirements of modelling these types of structures, now commonly in use, and how the requirements varied depending on the type of abutment/foundation considered.