Superstructure Strengthening Works Design to allow Jacking
Located approximately one kilometre east of Cardiff Central Station Adamsdown Footbridge carries a public footpath, on 3-spans, over the South Wales Main Line and the Bute Dock Branch line as well as Adamsdown Lane. The superstructure, reconstructed in 1951, consists of a reinforced concrete deck supported by steel longitudinal girders suspended from a steel bow arch via a series of vertical ties.
The substructure comprises one steel trestle pier in the ten-foot, one brick pier adjacent to Adamsdown Lane at the north and an abutment at each end.
The footbridge has been identified as requiring an increase to the vertical gauge to provide OLE clearance as part of the Great Western Electrification Project.
Additionally, it has been proposed to provide increased redundancy against impact for the central trestle.
New emergency trestles have been recommended under each bowstring span. Crouch Waterfall provided permanent and temporary works design.
Following detailed FEM analysis, considering a time history of the dynamic amplification effects imparted by the sudden drop of the deck onto the new emergency support, the proposed strengthening scheme was considered not viable. A revised scheme was developed with the aim of simultaneously allowing for jacking operations to be arried out from a much safer location than the central pier and provide better overall future resilience to the bridge.
Services safely away from the main construction.