Built for the 2008 Beijing Olympics, the Beijing National Stadium, or Bird's Nest, is a truly stunning piece of architecture. Consuming thousands of tons of concrete and steel, the building should stand for at least a century.
Here we explore how the building was erected and take a quick look at some of its vital stats.
What is the Beijing National Stadium?
The Beijing National Stadium, also known as the National Stadium or Bird's Nest, is a sports stadium in Beijing, China. It was conceived and built by a joint venture of architects including; Jacques Herzog and Pierre de Meuron of Herzog & de Meuron, project architect Stefan Marbach, artist Ai Weiwei, and CADG which was led by chief architect Li Xinggang.
It was originally designed for the 2008 Summer Olympics and Paralympics and is planning to be used again for the 2022 Winter Olympics and Paralympics.
The original concept for the building was the idea of a single thread wrapped around a ball.
"Layers of logical geometry give the appearance of randomness and an organic shape. Multiple pentagrams in the interlocking fabric of the elliptical structure are like the stars of the Chinese flag." - China Highlights.
The building has a floor space of 254,600 m2 and can seat as many as 91,000 people. 80,000 of its capacity is through fixed seating with the remainder possible using temporary seating.
The building's total gross internal volume is somewhere in-the-order of 3 million cubic meters.
It took over 36 km of unwrapped steel to build the stadium with a total weight of over 40,000 tons. The stadium is just over 330 meters long (from North to South) and over 220 meters wide (from East to West).
At its highest point, the stadium is just under 70 meters tall with its shortest elevation standing at 42.8 meters.
Interestingly the building also has some very sophisticated advanced energy and environmental conversation design features. These include, but are not limited to:
- Favorable natural ventilation,
- Maximized use of natural lighting,
- Rainwater harvesting and recycling, and;
- Solar photovoltaic power generation technology.
The stadium also makes use of a Ground Source Heat Pump system underneath its football field. This system works similar to an Air Source Heat Pump and helps provide heating and cooling to the building.
Its rainwater harvesting system provides freshwater that can be used for many water needs within the building from toilet flushing to fire suppression systems.
What is the Beijing National Stadium made of?
The Beijing National Stadium took around 3 years to complete with a total of over 40,000 tons of steel and 110,000 tons of concrete to build it. It has a designed lifespan of around 100 years.
This makes it one of, if not the world's largest steel structure. Construction began in December of 2003 with the building finally completed in March of 2008.
Pile foundations were dug to around 37 meters below ground level to support the enormous weight of the final building. With this complete, the inner body of the stadium was erected using 14,700 precast concrete slabs with 2mm tolerances to form the main seating areas.
"The stadium has two independent structures, a red concrete seating bowl and the outer steel frame around it at a 50ft distance. As this was an Olympic venue, there were many standards that the design consortium had to conform to. Everything from the width of the track to the size and location of the long and high jump pits needed to satisfy the requirements set out by the International Olympic Committee (IOC) and the International Amateur Athletics Federation (IAAF)." - designbuild-network.com.
Internally the Beijing National Stadium has 24 trussed columns, each weighing 1000 tons. Because of their size, they were assembled in parts onsite as they were too heavy to be lifted into place using cranes.
Construction of the outer shell commenced in 2005. Once all the columns were assembled and in place, smaller beams were welded between the structure to provide it with added strength and to enhance its unique, elliptical crosshatch appearance.
This structure also enabled the designers to meet the Chinese government's requirement for the stadium to be able to withstand an 8.0 magnitude earthquake.
The final stage of construction required the installation of the third set of beams from which to hang the stadium's transparent, polymer membrane which provides roofing between the steel beams (seen in the image above).
"The stadium is not just a remarkable piece of architecture and structural engineering, but also sets global standards for spectator experience. It was designed around people – ensuring optimum view, comfortable seats and maximum enjoyment of sporting events.
To maintain the atmosphere and provide a superb stadium experience, the roof was clad with ethyl tetrafluoroethylene (ETFE) panels on the upper surface and an acoustic membrane on the lower surface." - ARUP.
It was originally planned to have a retractable roof, but this was scrapped due to an internal steel shortage at the time. Instead, a new specially designed roof was designed that was supported by temporary pillars initially.
These were finally removed when the engineers were satisfied that the Bird's Nest's outer frame could support the weight on its own.
How much did the Beijing National Stadium cost?
According to sites like the Design-Build Network, the total construction budget for the stadium was $423 million). This was a small, but significant, fraction of the total $40 billion or so spent on preparing Beijing for the Olympics.
7 takeaway facts about the Beijing National Stadium
1. The Beijing National Stadium was specifically designed and built as a venue for the 2008 Beijing Olympics. It also hosted the Paralympics of the same year. It is planned that the stadium will be used once again for the 2022 Winter Olympics.
2. It took around 5 years to complete and cost a total of $423 million. Its construction consumed over 40,000 tons of steel and 110,000 tons of concrete.
3. It is one of the biggest steel structures in the world and one of the world's biggest stadiums. The stadium should stand for at least 100 years.
4. the Beijing National Stadium has been designed to withstand a magnitude 8.0 earthquake.
5. Its unique design was inspired by the idea of a thread wrapped around a ball.
6. The stadium is something of a tourist attraction in Beijing with between 20,000 and 30,000 visitors a day. It costs around 50 yuan ($8) per admission.
7. The stadium has a massive seating capacity and can comfortably hold 91,000 people. This includes 80,000 permanent seating with an additional 11,000 made possible through temporary seating.