The new terminal at Barajas Airport in Madrid will be the largest in Spain, handling 35 million passengers a year. Including the car parks and rail station, more than one million square metres of space are under construction.
The main terminal is on five levels: the lowest two are below ground; the upper three, of concrete-frame construction, are covered with an undulating roof supported on central 'trees' and oversailing at the edges to provide sun shading. The trees comprise concrete columns that branch out to support two pairs of inclined steel tubes; each tree supports a pair of double-S-shaped steel roof modules that span 72m.
On the glazed north and south facades the roof is propped on external canted Yshaped columns at 18m centres. A series of 'kipper' trusses supports the glazed facade.
The trusses are tensioned to resist wind loading and formed of five horizontal cast stainless steel arms connected by pairs of stainless steel rods.
The trusses were factory assembled, delivered to site and loosely pinned and bolted. A set of ties and jacks were set up behind them and tensioned to draw the roof and floor beam together to a maximum loading of approximately 60 tonnes.
The trusses were then attached, tested and loaded to approximately 40 tonnes.