Abstract
Analysis of integral bridge structures shows that lateral earth pressures on the end abutments have a dominant influence on the sizing of bridge components. Thermal cyclic movements induced by deck expansion cause densification of backfill material, leading to the build-up of high pressures behind the abutments. Measures to reduce these pressures by the use of alternative backfill materials can be highly beneficial to the structure as a whole, with extra expenditure on the backfill material being offset, and in some cases exceeded, by savings in material quantities in the rest of the structure and build time. This paper examines three contrasting backfill options that were considered during the design of Cottington Road overbridge in Kent: 6N granular backfill; lightweight expanded clay; and expanded polystyrene blocks. Although more expensive as a material than the other options investigated, the expanded polystyrene block option was selected as the most economical solution for this particular structure owing to large material savings in the foundations, abutment walls and wing walls as a direct result of reduced lateral pressures. Although it did not form part of the decision-making process, this paper also shows a significant saving in embodied and transport-related carbon dioxide emissions through preferring expanded polystyrene blocks to expanded clay.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Proceedings of the Institution of Civil Engineers - Bridge Engineering
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.