The complex engineering design challenges of masonry arch bridge rehabilitation

The need to repair or strengthen masonry arch bridges and viaducts to meet modern performance requirements and to address the effects of lack of maintenance, increasing levels of wear and tear and the risk of collapse has led engineers to develop a variety of rehabilitation techniques. Successful selection and specification of the most appropriate form of rehabilitation is a complex issue. A number of challenges must be taken into consideration when developing and evaluating viable alternative repair or strengthening measures. Incorrect decisions are often not only financially costly but can also result in irreversible damage to structures of historical and cultural importance. This paper provides an overview of the design challenges and a commentary on some of the potential problems arising from the selection of inappropriate materials, repair or strengthening measures.