Masonry arch bridges have proved to be resilient, long-lasting structures, and continue to form a crucial part of the railway and regional highway networks of the UK and many other countries around the world.
However, some aspects of their behaviour remain poorly understood. This can lead to bridges being needlessly strengthened (or even demolished and replaced), or, alternatively, being subjected to loading regimes that cause long-term damage, impacting lifespan.
In this presentation, key elements of the recently published CIRIA C800 guidance on the assessment of masonry arch bridges will be highlighted, including the use of the permissible limit state (PLS) to identify bridges likely to be prone to damage under service loads.
Also, two analysis methods recently developed at the University of Sheffield will be described: (i) the new ‘Thrust Layout Optimisation’ (TLO) analysis method, which overcomes issues associated with traditional thrust line analysis; (ii) extensions to the ‘Discontinuity Layout Optimisation’ (DLO) method to identify 3D failure modes in arches.
Colin Smith, Professor, Department of Civil and Structural Engineering, University of Sheffield
Colin has a long standing interest in the behaviour of masonry arch bridges. As part of this he has a particular interest in how the infill material used to provide a level traffic surface influences the mode of response of a given bridge, and also in the development of novel analysis tools for such structures.
Colin was co-author of the CIRIA guide 'Guidance on the assessment of masonry arch bridges', published in 2022, authored with Matthew Gilbert, Graham Cole and Clive Melbourne. He is also a Director of LimitState, a company that develops a range of structural and geotechnical engineering software tools for civil engineers.