Masonry arch bridge assessment

Masonry arch bridges, common in the UK's transport system, can be more than 100 years old. Modern computer-based analysis now enables engineers to understand how such bridges cope with the loads they carry. In 2002, the International Union of railways (UIC) launched a new study into masonry arch bridges and sponsored the development of a new version of the well-known RING masonry arch bridge analysis software LimitState:RING 2.0. The software can be used to identify the factors of safety on any specific vehicle loading at collapse allowing the user to clearly visualise the associated failure mechanisms and whether this involves 1 or 2 or more spans. LimitState:RING 2.0 also has the ability to analyse the cause of cracked masonry (a common feature of load-bearing structures) and study elements such as soil-arch interactions. The problems of understanding the diverse geometry of internal masonry (backing, haunching and spandrel walls) is addressed with a CAD import facility which will be included in the next release of LimitState:RING. The software has been used by Dr Matthew Gilbert (University of Sheffield) to analyse the Old Bridge in Mostar (Bosnia and Herzegovina).