Capacity of a nineteenth century iron-arch bridge in Leeds, UK Available to Purchase

Leeds Bridge crosses the River Aire in the city centre of Leeds, UK. Built in 1871, this grade II-listed iron-arch structure is currently restricted to vehicles over 7·5 t (other than buses and fire engines) due to a weak deck. A proposed trolleybus system was planned to go over the bridge, requiring it to be reassessed. The single 32 m skew span bridge is made up of ten arched ribs – two external ribs made from cast iron with the eight internal ribs, plus all the cross-girders and bracing, made from wrought iron. This paper describes the assessment of the bridge using a three-dimensional space-frame model supplemented by a three-dimensional finite-element model of one rib. The assessment concluded that the strengthening requirements to carry the required vehicle loading would be limited to replacement of the mass concrete infill.