Building Name – Bird’s Nest Beijing National Stadium
Location – Beijing, China
Owner – Chineese Government
Architect – Herzog & De Meuron
Contractor – CITIC Internationals Contracting Inc
Consultants – Ove Arup & Partners (MEP & Structure)
Year of Start – 24 December 2003
Year of End – March 2008
- The stadium has a gross volume of three million cubic metres and is considered to be the world’s largest enclosed space. It is also the world’s largest steel structure with 26km of unwrapped steel used.
- The 91,000-seat stadium was designed to incorporate elements of Chinese art and culture.
- The stadium extends 333m from north to south and 294m from east to west, with a height of 69.2m. The stadium design included demountable seats of 11,000.
- Pile foundations had to be dug 37m below ground level to bear the weight and horizontal forces generated by the structure. Then the functional inner body of the stadium was built. 14700 precast concrete slabs, all formed within 2mm tolerance to hold the seating, were slotted together.
- The stadium has two independent structures, a red concrete seating bowl and the outer steel frame around it at a 50ft distance.
- The circular shape of the stadium represents bird’s nest, with its pattern inspired by Chinese-style crazed pottery.
- The concourses are wide and spacious for making the refreshment and merchandising stalls easily accessible. There is also a large mixed-use retail development beneath the stadium featuring shops, restaurants, cinemas, a health club and parking.
- The football field of the stadium with an area of 8,000m² provided enough space for the underground pipes of the geothermal heat pump (GHP) system, through which ground-source energy is collected. In winter, the system absorbs the heat from the soil and helps heating the stadium, while in summer the coldness from the soil is stored which cools the stadium.
- Computational fluid dynamics (CDF) simulation based on the Games-time situation has been used to calculate the temperature and airflow speed at each angle of the structure and optimise all ventilation facilities accordingly.
- To minimise the formwork construction on the bowl, the design team used precast concrete.
- A terrace of L-shaped precast units spanning areas between the supporting reinforced concrete in situ beams will make up the section of the middle and upper tiers.
- The stadium is supported by 24 main columns of 1,000t each, far more than the weight of those in a conventional stadium and spaced in what appears to be a random pattern.
- The 3D steel roof spans a 330m-long by 220m-wide space.
- The steel structure had to be supported by 176 hydraulic jacks during its construction while the structure was not capable of self-sustainment. Each crane was capable of holding 300 tons, each with an accuracy of one millimeter. Later, the hydraulic jacks were removed at once to check the stability of the structure of the stadium.
- The geometry of the roof was worked out from a base ellipse of which the major axis measures 313m and the minor axis measures 266m.
- The façade’s external surface has an inclination of approximately 13° to the vertical. As China is highly vulnerable to earthquakes, the roof was separated from the seating bowl to help make the structure earthquake resistant.
- The stand of the stadium is a seven-storey shear wall system with a concrete framework.
- The upper part of the stand and the stadium steel structure are actually separated from one another, but both of these are based on a joint foundation.
- The roof is covered with a double-layer membrane structure, with a transparent ETFE (ethylene tetrafluoroethylene) membrane fixed on the upper part of the roofing structure and a translucent PTFE (polytetrafluoroethylene) membrane fixed on its lower part. A PTFE acoustic ceiling is also attached to the side walls of the inner ring.
- The bowl of the structure is split into eight zones, each with its own stability system, making each zone effectively as its own building.E
- Entrance to the stadium is controlled by tripod barriers supplied and fabricated by Kaba Gallenschütz of Germany. The project involved the installation of 138 of these units at the 12 entrances to the stadium.