Spatial arch rib with shell arch bridge design proposal

A footbridge proposal longlisted in the Salford Meadows Bridge International Design Competition is presented in the present paper. The submitted solution is described, as weil as its structural behaviour.

lt is environmentally friendly. lt employs a cutting edge bridge type, a recently patented material and innovative lighting.

The footbridge is a spatial arch bridge, a contemporary bridge type which has recently been used for city landmarks. However, it would be the first imposed curvature arch bridge with a shell system structure, and the first S-shape imposed curvature arch bridge, to the authors' knowledge. The arch and deck are coincident in plan view (imposed curvature). Lt employs an hybrid system of a spatial arch rib and a shell arch. This geometry is based on previous research studies of SABs behaviour. The shell helps the arch to resist out-of-plane forces typical from SABs.

Acting as a focal point the bridge is clearly visible from the junction with Oldfield Road, creating a landmark as required in the competition. Lts elevation and design opens up the bridge to the surrounding environment, forming two piazzas at either end. At the Crescent the piazza enables people to circulate and flow easily onto the bridge, meandering towards the Meadows. At the other end the piazza celebrates the views of the Meadows from ist elevated position. Here the ground has been raised to receive the bridge enabling these vistas and the bridge to be DDA compliant. Both piazzas serve as nodes, links to the different sites on either side of the bridge, whilst also assisting pedestrian flow and developing into their own spaces, as places to sit, relax and enjoy the view.