Entry tags:
birds nest 2008
A little less than 20 hours until possibly the most contentious Olympics in the last 20-something years opens in Beijing. Without going into what is so contentious about it - you'd have to be living on Pluto if you've missed the flame wars both sides have been throwing - let's have a look at the glorious National Stadium, otherwise known as the Bird's Nest.
Design
The Bird Nest, designed by Swiss architect Jacques Herzog and Pierre de Meuron, was chosen out of 89 design proposals. Initially it was oblong-shaped, flatter, with a hollow centre. After reflections by the public that it looked like a dunny, it was reworked with an outer mesh-like structure, now looking like a bird's nest that's fallen out of the tree onto the ground - hence "Bird Nest". It really ain't such a fond name.
The official statistics are: 333 metres by 294 metres, with a height of 69 metres. It has permanent seating for 80,000 people (which is like a fingernail of the Chinese population) and an additional 10,000 seats can be added temporarily. It used 42 thousand tonnes of steel. That's about 42 thousand small cars, in a space that would normally park about a third that number.
The construction began on Christmas Eve in 2003, but was paused half a year later. There were major problems with its structure.
Weight
There are 24 steel pillars that support the roof, each of which exert about 4000-5000 tonnes of force per square metre. The area in which Bird Nest is built contains a lot of groundwater, and the water table has been fluctuating for several years, which makes it unsafe for heavy infrastructure to be built over it.
The initial proposal anticipated 136 tonnes of steel would be used, and was condemned by experts as "expensive and heavy, completely opposite to the lightweight ideal of modern sports infrastructure". After a number of senior academics forwarded a letter to Wen Jiaobao, the design was reviewed.
Roofless
The trimmed down design included the removal of a moveable roof. In a city that boasts temperature extremes of -27 degrees to 42 degrees Celsius, from freezing winters to rainy summers, this move just about halved its usefulness. The ramifications have been experienced even before the Games began - the first dress rehearsal was greeted with a downpour that left performers soaked to an inch of their lives.
There also appears to be problems with its rain pipe system, leading to a number of leakages around the entrances and in the rooms under the seating area.
Steel mesh
The 42 thousand tonnes of steel are welded together into a complex mesh, with the welding surfaces adding up to over 60000 metres. The welding technology and technique is therefore essential to the stability of the overall structure. A Korean engineering expert remarked of Bird Nest that under high temperature welding, the internal structure of the steel inevitably deforms a little. The danger arising out of these deformations take 8 to 12 months to stabilise to a level 30-40% of original, and only entirely disappears after 10 years.
A 100-metre long steel pipe can naturally expand 2 centimetres under temperature changes. In a structure where many different lengths and shapes of steel are welded together in a complex way, the different expansion and contraction rates of these steel beams can potentially cause bending and twisting. If this coincides with violent vibrations - such as tens of thousands of people expected to be cheering during the opening ceremony - there is the danger that the steel would begin to resonate and split.
Lighting
Under strong sunlight, the steel mesh casts a confusing lattice of shadows onto the grass field below, making it impossible to see what's happening on the field during the day. In response to public panic, it was decided that a thin polymer shielding made of ETFE would be installed on the ring-like "roof" of the stadium. ETFE has a transparency of 30% and can function as a sunshade, and is also able to give some protection against the elements, although its efficiency in this situation has yet to be revealed. Unfortunately, ETFE has the tendency to magnify sound, especially that of rain...
Precious polymer
ETFE, though cheaper than glass, is still an expensive choice. China is unable to produce ETFE, and the import price reaches 2000 RMB per square metre (about AUD$400), which would amount to hundreds of millions of RMB for the entire structure.
Due to the climate and pollution in Beijing, the exporting company could only promise 10 years of lifespan for the polymer, as opposed to more than 20 years in Europe. Any natural occurences such as sandstorms or hail, or the general pollution, would greatly shorten its useable life.
Another lethal problem inherent in the polymer is its vulnerability to puncture. Because the area is surrounded by acres of forested Olympic park, birds would inevitably be attracted to the area. The ETFE covering is extremely sensitive to scratching and puncture by bird claws, as well as possible corrosion by bird droppings, so bird-repelling devices had to be installed.
The irony...the Bird Nest that cannot tolerate birds.
Fear of Fire
The expensive ETFE is stable under normal temperature ranges but melts easily under high temperatures. According to the main director of construction, Tan Xiaochun, the EFTE melted during fireworks trials and had to be replaced. Normal fireworks can reach 400 degrees C when ignited. These had to be replaced with low temperature fireworks that would reach only 270 degrees, which limits the range of fireworks that can be displayed.
The entire structure took 3 years to construct, with 7000 workers working 12-hour shifts. According to the British Sunday Times, at least 10 workers died at the construction site, with witness accounts of a worker falling to his death. In the end, Beijing would only admit to two deaths. A large number of residents were forcefully evicted from their homes to make way for the grounds.
It is rumoured that the stadium cost 7 billion RMB to construct (a little less than 2 billion AUD), compared to the 690 million of the Sydney Olympics stadium. That's mightily expensive for something so precariously unstable, frustratingly high maintenance and widely useless.
All for the "face" of "China".
Source: Part A Part B
Design
The Bird Nest, designed by Swiss architect Jacques Herzog and Pierre de Meuron, was chosen out of 89 design proposals. Initially it was oblong-shaped, flatter, with a hollow centre. After reflections by the public that it looked like a dunny, it was reworked with an outer mesh-like structure, now looking like a bird's nest that's fallen out of the tree onto the ground - hence "Bird Nest". It really ain't such a fond name.
The official statistics are: 333 metres by 294 metres, with a height of 69 metres. It has permanent seating for 80,000 people (which is like a fingernail of the Chinese population) and an additional 10,000 seats can be added temporarily. It used 42 thousand tonnes of steel. That's about 42 thousand small cars, in a space that would normally park about a third that number.
The construction began on Christmas Eve in 2003, but was paused half a year later. There were major problems with its structure.
Weight
There are 24 steel pillars that support the roof, each of which exert about 4000-5000 tonnes of force per square metre. The area in which Bird Nest is built contains a lot of groundwater, and the water table has been fluctuating for several years, which makes it unsafe for heavy infrastructure to be built over it.
The initial proposal anticipated 136 tonnes of steel would be used, and was condemned by experts as "expensive and heavy, completely opposite to the lightweight ideal of modern sports infrastructure". After a number of senior academics forwarded a letter to Wen Jiaobao, the design was reviewed.
Roofless
The trimmed down design included the removal of a moveable roof. In a city that boasts temperature extremes of -27 degrees to 42 degrees Celsius, from freezing winters to rainy summers, this move just about halved its usefulness. The ramifications have been experienced even before the Games began - the first dress rehearsal was greeted with a downpour that left performers soaked to an inch of their lives.
There also appears to be problems with its rain pipe system, leading to a number of leakages around the entrances and in the rooms under the seating area.
Steel mesh
The 42 thousand tonnes of steel are welded together into a complex mesh, with the welding surfaces adding up to over 60000 metres. The welding technology and technique is therefore essential to the stability of the overall structure. A Korean engineering expert remarked of Bird Nest that under high temperature welding, the internal structure of the steel inevitably deforms a little. The danger arising out of these deformations take 8 to 12 months to stabilise to a level 30-40% of original, and only entirely disappears after 10 years.
A 100-metre long steel pipe can naturally expand 2 centimetres under temperature changes. In a structure where many different lengths and shapes of steel are welded together in a complex way, the different expansion and contraction rates of these steel beams can potentially cause bending and twisting. If this coincides with violent vibrations - such as tens of thousands of people expected to be cheering during the opening ceremony - there is the danger that the steel would begin to resonate and split.
Lighting
Under strong sunlight, the steel mesh casts a confusing lattice of shadows onto the grass field below, making it impossible to see what's happening on the field during the day. In response to public panic, it was decided that a thin polymer shielding made of ETFE would be installed on the ring-like "roof" of the stadium. ETFE has a transparency of 30% and can function as a sunshade, and is also able to give some protection against the elements, although its efficiency in this situation has yet to be revealed. Unfortunately, ETFE has the tendency to magnify sound, especially that of rain...
Precious polymer
ETFE, though cheaper than glass, is still an expensive choice. China is unable to produce ETFE, and the import price reaches 2000 RMB per square metre (about AUD$400), which would amount to hundreds of millions of RMB for the entire structure.
Due to the climate and pollution in Beijing, the exporting company could only promise 10 years of lifespan for the polymer, as opposed to more than 20 years in Europe. Any natural occurences such as sandstorms or hail, or the general pollution, would greatly shorten its useable life.
Another lethal problem inherent in the polymer is its vulnerability to puncture. Because the area is surrounded by acres of forested Olympic park, birds would inevitably be attracted to the area. The ETFE covering is extremely sensitive to scratching and puncture by bird claws, as well as possible corrosion by bird droppings, so bird-repelling devices had to be installed.
The irony...the Bird Nest that cannot tolerate birds.
Fear of Fire
The expensive ETFE is stable under normal temperature ranges but melts easily under high temperatures. According to the main director of construction, Tan Xiaochun, the EFTE melted during fireworks trials and had to be replaced. Normal fireworks can reach 400 degrees C when ignited. These had to be replaced with low temperature fireworks that would reach only 270 degrees, which limits the range of fireworks that can be displayed.
The entire structure took 3 years to construct, with 7000 workers working 12-hour shifts. According to the British Sunday Times, at least 10 workers died at the construction site, with witness accounts of a worker falling to his death. In the end, Beijing would only admit to two deaths. A large number of residents were forcefully evicted from their homes to make way for the grounds.
It is rumoured that the stadium cost 7 billion RMB to construct (a little less than 2 billion AUD), compared to the 690 million of the Sydney Olympics stadium. That's mightily expensive for something so precariously unstable, frustratingly high maintenance and widely useless.
All for the "face" of "China".
Source: Part A Part B