China's National Stadium, or the Bird's Nest, as it has become known, is the world's largest steel structure and the most complex stadium ever constructed. It is "one of the key engineering marvels in the world today."
来源@视觉中国
As a testament to its significance, it's on the city's north-south axis, which also includes the Forbidden City, Tian’anmen Square and the Temple of Heaven, travelling south. It is on the Olympic Green about 8km from the center of Beijing.
Construction of the National Stadium began on December 24, 2003, and was completed in March, 2008. The total cost was more than 423 million dollars, a tiny fraction of the 40 billion USD spent on Beijing in preparation for the Olympics.
来源@视觉中国
It is 333 meters long from north to south, 294 meters wide from east to west, and the highest point is 68.5 meters.
Ground Work: 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. Each of the 24 supporting columns weighs 1000 tons, no lifting equipment in the world is able to lift it.
Because of Beijing's location, the stadium had to be able to withstand an earthquake. The purest steel ever developed in China allowed the designers to combine light weight with strength to provide maximum resistance to seismic forces.
来源@视觉中国
Welders had to be specially trained to join the interlocking steel sections together due to the low sensitivity to welding of the new type of metal.
The 11200 ton roof was supported by temporary columns until the moment of truth when the jacks were released and the web of the Bird's Nest held its own weight.
来源@视觉中国
The Bird's Nest was the main venue of the 2008 Beijing Olympic Games, when it had a capacity of 91,000 spectators. The stadium now has a capacity of 80,000, after temporary seating was removed.
The Bird's Nest hosted the opening ceremony, athletic events, the football final and the closing ceremony of the 2008 Beijing Olympic Games, which took place from August 8 to August 24, 2008.
来源@视觉中国
It was also the venue for the 2008 Beijing Paralympics athletics and ceremonies from September 6 to September 17, 2008. The stadium will continue to host international and domestic sporting events, such as football matches.
Source: chinahighlights.com
