8/9/2019 EXPO'98 - Pavilhão de Portugal

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PAVILH� DE PORTUGAL

 

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PAVILH� DE PORTUGAL

Details:

The Pavilhão de Portugal (Portugal Pavilion) was one of the most emblematic and mostcentrally positioned in the EXPO' 98 enclosure, whilst also being used for official functionsduring the exhibition.The pavilion is made up of two main structures: the Ceremonial Square, an open space ofbold architectural conception, and the actual Pavilion of Portugal, with a basement and twofloors, which develop around an interior patio.The curved roof covering of the square, with an approximate area of 3.250 m2, has theparticularity of being composed of a single short span measuring 65m in length and 50 in

width, with the roof reaching a maximum of 17m in height at the lateral extremities and aminimum of 14m in the middle of the span. The total covered area is 3.762 m2, and thestructure has a total length of 82,5 m for a clear span of 75 m. It has a capacity for 6.000seated places.The foundations are made up of reinforced concrete piles cast in the soil and capped bybeams in a continuous foundation braced between each other by reinforced concretestruts. The support structure of the covering, two porches erected perpendicularly to theplatform, consist of reinforced concrete abutments, braced between them by a membrane(wall) also in reinforced concrete, supporting in the top of the arch the cable fixing slabbearing the curved roof.The covering is a parabolic curved roof , in pre-stressed reinforced concrete with aconstant thickness of 20 cm, with the concrete being of light aggregates (specific weight inthe order of 18 kN/m3) to reduce its own weight, the total of which is around 1.400 tons.The curved roof is supported by pre-stressed and galvanised steel cables 58 cm fromthem to the axis, with each cable consisting of seven sheathed tendons. Between thesupport structures of one side and the other and the beginning of the curved roof, thecables have a free trajectory of 1,56 m, with the curved roof being 64,38 m in its extensionand 50,16 m in its width.The structural behaviour of the curved roof in itself is of a suspended structure of thecatenary type (similar to a parabola in the way it is a very taut curve), its rigidity and,consequently its thickness being irrelevant to the amount of curvature. In other words theconcrete of the curved roof simply serves to give expression to the curved roof and toprotect the pre-stressing cables.The pull of the supporting cables, which is of considerable force, is supported by thestructure of the abutments which, at the base, are joined by struts which practically permitsa self balancing process.With regard to seismic features, the curved roof functions as an independent oscillator ofthe sustaining structure but transmitting to this the inertia forces that it generates.The Pavilion itself has a maximum height of 14,6 m, a total building area of approximately6,940 m2 and a floor area of 18.920 m2 distributed over four used levels. Its site plan

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8/9/2019 EXPO'98 - Pavilhão de Portugal

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PAVILH� DE PORTUGAL

dimensions are 90 by 73 m. In the North-west corner a structure is prominent, alsohaving two floors measuring 22,5 by 16,5 m, and separated from the main building on 1st

floor by a 5m high gallery. The building is developed around a patio, 22,5 by 20m, filledwith earth up to the level of the ground floor - in order to allow the plantation of a largetree. In the North extremity, the design of several floors includes a U shape, with theinternal space being extended by walls that demarcate landscaped areas.Its peripheral walls are in reinforced concrete and the interior structure is made up ofresistant reinforced concrete interior cores, with pillars and metallic beams, and laminatedbeams on the higher floors. The slabs on the higher floors are of a steel and light concretestructure mix (with supporting metal plate.)The foundations of the building are of reinforced concrete piles driven into the earth,which is justified given the nature of the land on the banks of the Tejo. The basement is

made of an area spread foundation slab topping the piles, and of containment walls,pillars, interior resistant cores and a flat slab on the reinforced concrete ground floor.In terms of structural behaviour, the gravity and absorption actions are supported byresistant vertical elements (peripheral and interior pillars and walls). In terms of horizontalactions, with particular emphasis on seismic features, the resistance comes basically fromthe peripheral walls (shear walls) and from the reinforced concrete core structure.Date of Conclusion: 1998Value: 23.500.000 ?Amounts involved in the Work:Concrete: 8.503 m3Steel: 1,273 tonsSteel cables: 62 tonsCurved roof scaffolding: 45.000 m3Props 1200 diam: 56 unitsProps 800 diam: 40 units

Developer: Park Expo'98, S.A.

Project: Architect Álvaro Siza Vieira

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