Masonry arch bridges are long-lived structures that continue to form a vital part of our transport infrastructure. However, inaccurate assessment can lead to masonry arch bridges being needlessly infilled or demolished and replaced, at great cost to the planet. 

ICAIR Director Professor Matthew Gilbert has led the drafting of new CIRIA guidance on the assessment of masonry arch bridges. The guidance, CIRIA C800, builds on recent research findings and advice already available in CIRIA C656, DMRB and Network Rail codes. Specifically, the guidance promotes the use of the Permissible Limit State (PLS), the point beyond which progressive load induced degradation occurs under service loads during the intended life of a bridge.

The guidance, which can be freely downloaded from the CIRIA website, was announced on June 8 2022 at the NCE Future of Bridges event and will be formally launched at an event held at the Institution of Civil Engineers in London on 30 June 2022 - further details, including registration links, are available here.