Issue 5

The Wembley Stadium Station Footbridge (Fig 1) is a new pedestrian bridge linking Wembley Hill Road / Wembley Triangle and South Way in London, UK and serves as a crucial conduit for pedestrians visiting the new Wembley Stadium. It spans the Chiltern line suburban railway services between Marylebone, Aylesbury and Birmingham (Fig 2).

Halcrow Group Ltd was appointed by London Borough of Brent and the London Development Agency to undertake project management, design development, and site supervision on the strategically important southern stadium approach. The bridge has two primary functions, firstly to carry pedestrians over the railway and provide access via staircases and lifts to the platforms: this access is provided either side of the bridge one side controlled for use on stadium event days and the other side being part of the station revenue protected area. Secondly, the bridge forms a landmark structure which is easily recognisable, opening up the gateway to the national stadium along the Wembley Route, and serving as an attraction for future development, investment and regeneration.

A number of options for the bridge form were considered. The selected option was judged to have a high visual, aesthetic, landmark and curiosity value and one that would create an identity for the location, fulfilling the requirements to enable regeneration of the area. It was also considered to have the lowest risk when considering programme, construction, cost, security and technical approval.

Billy Ahluwalia, BSc (Hons), CEng, MICE, MIStructE, MASCE, MAPM
Halcrow Group Ltd

Krishna Kumar Ganasalingam, BSc (Hons), CEng, MICE, MIEM(Malaysia), PEng(Malaysia)
Halcrow Group Ltd

David Phillips, BSc, MSc, CEng, FIStructE, FICE
Halcrow Group Ltd

Harold Marais, BEng, MSc, MAPM
London Development Agency

This paper reports on an evaluation of the behavior of X-shaped shear connectors for timber-concrete composite bridge decks. Direct shear tests of the connectors, which were subjected to a total of 2 x 10⁶ load cycles, indicated that their ultimate capacity was not affected by the fatigue cycles and that accumulated fatigue damage was the result of an initial slip that tended to stabilise after 1 x 10⁶ cycles. Three composite girders with Tshaped cross section were loaded to failure after being subjected to 1 x 10⁶ cycles. The test results indicated that the X-shaped connection conferred high resistance and stiffness on the composite system, offering an excellent alternative for composite bridge decks. To conclude, details of the design and load testing of a 7m span composite bridge in Brazil are presented and the test results are compared with those of a timber bridge, confirming the advantages of the composite system.

Julio Cesar Molina, DSc, CEng
Department of Structural Engineering, University of São Paulo USP/EESC, São Carlos, SP, Brazil

Carlito Calil Junior, DSc, CEng Department of Structural Engineering, University of São Paulo USP/EESC, São Carlos, SP, Brazil

For many engineers, the steel box girder story starts with disaster. The memories of the tragic events of 1970 and 1971 are still raw for some, and the implications have been far reaching. But the story is also one of bold innovation, lessons learnt and ultimate success. This paper explores the short history of the steel box girder and reflects on how it has shaped the evolution of the popular modern bridge structures we see today.

Ian Firth, BSc, MSc, DIC, CEng, FIStructE, FICE, FConsE
Flint and Neill Ltd