What did the Bird’s Nest have to face in order to become what it is today?
- Fault lines
- Olympic guidelines
- Security reassurance
- Steel frame design
- Steel twisting and curving
- The unloading
Steel is known as one of the best and most versatile construction materials in the Philippines. It can be found in countless buildings and infrastructures. It’s a wonderful material that can be customized to fit the specifications of different kinds of projects.
Out of the many steel structures in the world, there just are a handful of buildings that truly showcase just how amazing the material is. One of these is the Bird’s Nest in Beijing. This building was made specifically to accommodate the 2018 Summer Olympics. And as we all know, it delivered in not only becoming a worthy venue for the Olympics but also in becoming a national symbol of Beijing.
It’s construction, however, was not all smiles and sunshine. It went through a number of issues during its time that required a lot of ingenuity and creativity from both the design team and the construction personnel. Detailed in this article are the many challenges that the construction of the Bird’s Nest faced, and how the team solved each:
China is surrounded by some of the deadliest fault lines in the world. With that in mind, the stadium needed to be earthquake proof. It needed to be safe from even the strongest recorded earthquakes.
The architectural director, J Parrish stated that “The basic problem with earthquake design is that the building is so large. What’s going to happen on one end of it might not be what’s happening on another end of it…”
With this statement in mind, they decided on constructing the steel frame as a separate structure, so that even if the concrete bowl was to crack, the steel frame—the façade of the building, will be unaffected. To add another layer of earthquake safety, the bowl was separated into six segments. This allows the building to absorb the energy of the earthquake without violently shaking itself to pieces.
The Olympic Guidelines
The Bird’s Nest was being built specifically to accommodate for the Olympics. That means it needs to accommodate high-tech systems, giant screens, and world-class seating with great views of the field. The interior design plan was left to their British partner Arup which quickly switched their mindset to focus on the heart of the building, in this case, the seats. The design revolved around quality seating, and everything else that you would usually see in a sport’s stadium followed afterward.
An unexpected incident led to the temporary halt of the construction. They had their blueprints re-examined by a group of experts by the Chinese to further ensure that it meets their safety guidelines. They also tried to forecast and simulate possible disasters that might happen. As it was going to be used for such a large event, the Chinese government needed to ensure that the risk of a disaster happening is virtually near zero.
The construction was allowed to continue with only minor changes to the design. The most notable being the cancellation of the retractable roof and lessening of the number of seats.
Steel Frame Design
They needed to plan out how to weave the steel beams into a bird’s nest. It needed to look as if it has a random pattern with steel providing the necessary amount of support for the whole structure.
They decided on having three sets of beams. 24 pillars in the form of trusses will serve as the bones of the structure. This backbone keeps the building from falling down. Another set of beams are placed between the beams of the first set. They function just like tendons in a human body. They link all the beams to form a braided structure. Lastly, the third set of beams support the stairways that connect the multiple levels. They also provide a framework for the roof membrane covering.
The interlocking nature of the steel beams, when seen from afar, gives it the illusion of being a bird’s nest.
Steel Twisting and Curving
During the time, there wasn’t any kind of steel that was available that would satisfy the requirements of the building. The steel beams needed there had to be extremely flexible without sacrificing strength and durability. With that being said, the team decided on creating a unique steel product that is specially made for the stadium. The steel needed to be able to stand up against the fiercest of earthquakes, all the while being very flexible and strong overall.
They ended up creating a special type of steel named the Q460. They didn’t use sheet piles like in the Philippines, rather they went with an ingenious design that required 4 steel plates that are 1.2 meters on the side. They were welded into a square structure and bent to the desired shape.
The steel parts are welded together to form larger steel sections, some of them get up to 12 meters long. An enormous crane aligns them precisely into place and then they’re welded for two to three days to ensure quality welding.
During construction, the steel frame was held in place by over 70 support columns so the structure, as of that moment, wasn’t standing on its own. The removal of this support columns was called the unloading. It was a scary and nerve-wracking situation. Eventually, all of the support was removed and the steel structure sunk 26.5 inches into itself as the stress was distributed to other parts of the structure.
At the end of the unloading, the Bird’s nest was a solid steel structure. Now all that’s left was the inside, which in actuality was the easiest part of the job. During this time, shops, high-tech devices, and large screens were put into place.
The Bird’s Nest took 3 years to complete just in time for the 2008 Summer Olympics. It’s a testament to the versatility of steel. And of course, it shows why steel is considered the best construction materials in the world.
The Bird’s Nest today is still one of the revolutionary marvels of the 21st century. It’s slick design and absolutely stunning façade makes it one of the most popular structures in the world. In the Philippines, construction equipment has only gone so far, and have contributed to only a handful of world-renowned projects.
Overall, the Bird’s Nest is one of the most ambitious projects in recent time and its construction along with all the people that contributed to its completion is worth of an immense amount of praise.