The most representative architecture at the 2008 Zaragoza International Exhibition is the Bridge Pavilion across the river Ebro. Designed by Zaha Hadid with the assistance of Arup engineers, the programme won the international competition held in 2005 ahead of 41 other submissions by architecture practices.
The Bridge Pavilion provides several functions. First, it is a pedestrian bridge, and main access to the tradeshow grounds enclosed by a loop in the river and bounded by extensive urban parkland. Second, it provides a series of elongated, interconnected exhibition spaces dedicated to the Expo 2008 theme: “Water: a unique resource”. Lastly, the dynamic fluidity of this slightly curving structure, of varying height
(15 to 30 m) and width (8 to 30 m), is an immediate landmark and symbol of the whole event to which it leads.
The Bridge Pavilion brings together architectural expressivity, spatial distribution, and technological structural know-how. Weighing some 5700 tons, the steel structure has two spans of 185 and 85 m, a third point of support being an island two-thirds of the way along the bridge’s length. The 10 piles supporting the bridge on the island have been sunk to a depth of 68 m.
Four diamond shaped “pods” issue from the curved bridge to create longitudinal, parallel and layered spatial configurations. The first offshoot starts right at the access ramp: a stem-like element that fans out into three exhibition pods with as many itineraries running parallel and at times in stacked fashion. The intersecting layout creates multiple internal views along the 4000 sq m of exhibition space out of a total surface area of 6415 sq m.
The experimental thinking already visible in other Hadid creations for public and exhibition programmes comes to fruition with this multifunctional infrastructure. Viewed from outside, the bridge’s flowing modular geometry of alternating solids and voids produces a multitude of different light reflections. Curved in plan, it melds with the landscape and exploits the constant direction of the wind to create a comfort-zone microclimate inside.
Of special note is the outer cladding. Curved steel panels on the lower part of bridge highlight its flexible geometry. On the upper part of the pods, glass-reinforced concrete [Fibre C] by Rieder panels in ten different sized modules and graduated tones form an experimental skin that casts a rich pattern of light and shading in keeping with this complex architecture.
This cladding grid resemble the optical art school of Victor Vasarely, with its three dimensional geometrical effects.