The assessment, strengthening and widening of Thames Bray Bridge

Abstract

The original Thames Bray Bridge was constructed between 1939 and 1961. It consists of a 112m long 82m span bridge. It was one of the UK’s first welded, stiffened, profiled plate girder bridge with a concrete deck connected with shear connectors. The bridge has undergone a number of inspections, assessments, strengthening and stiffening over the years. In 2015 planning for the upgrading of the highway to Smart Motorway status began. At Thames Bray Bridge there are no hard shoulders and so widening of the bridge was required. This paper outlines the strength assessment of the bridge, the assessment of resilience from failure of ties and of increased river flows due to climate change. It outlines the additional refined assessments carried out to more realistically estimate the capacity of the bridge. The paper outlines the local strengthening and the new asymmetric widening design that visually followed closely the original bridge.