Canning Town Flyover
The main span comprises a half through plate girder deck, 52m long, 12m wide with a skew angle of 46 degrees, fabricated from S355J2 and S355K2 steel to EN 10025-2[1]. The main girder depth varies from 2.6m at the supports to over 4.5m at midspan. A trial erection of the two main girders and transverse beams was carried out at Rowecord’s Newport works prior to site erection, which was completed within a single 50 hour rail possession using a 600t capacity crawler crane.
An unusual feature of this deck is the structural continuity with the adjacent precast beam spans, which was needed to avoid a highly skewed movement joint under the tracks. Such a joint would have resulted in unacceptable displacements of the permanent way under live loading. Continuity was achieved by connecting the two main steel girders to a substantial concrete diaphragm using post-tensioned bars. The precast beams of the adjacent deck are also cast into the diaphragm, and bearings between the diaphragm and substructure provide the required articulation.