The Bird’s Nest Stadium

Civil Engineering Consortium IIT Roorkee

5 min readDec 8, 2021

Introduction

Built on the Olympic Green, Beijing National Stadium, or commonly called as the Bird’s Nest Stadium, as it has become known, is the biggest stadium in Beijing and an important Olympic venue, which staged the 2008 Summer Olympics. The outer shell is the world’s largest steel structure, forming part of the most complex Olympic stadium ever constructed. The building cost of this stadium was around US$428 million. It has a capacity of 91,000 seats.The stadium comprises a seven-storey wall made of concrete. In addition, the roof of the stadium and the steel structure are not intact.

Design And Concept

The stadium was jointly designed by architects Jacques Herzog and Pierre de Meuron from Basel-based architecture team Herzog & de Meuron, project architect Stefan Marbach, artist Ai Weiwei, and CADG, which was led by chief architect Li Xinggang.The requirements for its design were that it had to be inspiring and be able to withstand an earthquake.It is saddle-shaped, but the interlocking steel parts resembling a lattice of twigs, make the name Bird’s Nest an obvious alias. 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.The entire Beijing’s stadium structure was then covered with a waterproof polymer membrane, allowing sunlight to pass through to the inner turf. The membrane also helps enhance stadium illumination, significantly reducing light reflections and shadows and creating an atmosphere suited to entertainment.

Giving spectators the best possible auditory experience was key in determining the materials and shape. Because the materials are phono-absorbent, the audience can hear sounds from all over the playing field at every point in the stands.

Construction

Beijing’s stadium took five years of work, its construction site first opening on December 24, 2003. Initial preparations were put in place along with the pile foundations, which had to be dug 36 metres (121 feet) below the surface to support the weight of the building.

Once the pile foundations were set up, the stadium’s internal structure — comprising 14,700 precast concrete slabs — was the first part completed. Twenty four supporting columns, each weighing 1,000 tons, were also part of this phase.

Massive columns were also needed to support the stadium roof, which weighs 11,200 tons. The steel netting that gives the stadium its shape was then built around the central section. This was a particularly complex construction phase, tipping the project’s final cost to $428 million in March 2008, when construction work ended.

Seismic Resistance

Being located in active seismic zones, the stadium had to be able to withstand earthquakes. So The Bird’s Nest is designed in such a way to resist a seismic level 8 event. The most secure element in terms of its earthquake resistance is the separation of the steel structure outside of the Bird’s Nest and the concrete structure of the bowl-shaped spectator area inside. As the vibration frequencies of steel and concrete are different, separation stops them from ripping each other apart during an earthquake.

Further The spectator area is structurally divided into six parts. If an earthquake occurs, the vibration frequency of each part would be different and released separately. The divisions act like expansion joints.In addition, the spectator escape provisions of this giant Olympic stadium are currently at the highest level among large stadiums. Tens of thousands of people can be completely evacuated within 8 minutes.

Challenges

One of the major structural challenges that the Beijing National Stadium faced was in its mode of construction. The steel bause the stadium for various events. Thrs used in constructing the stadium posed a major threat to the safety of people that the tragedy at the France airport terminal raised the issue of enhancing safety in the Beijing National Stadium.Hence, they had to come up with a different design for the roof, which could withstand catastrophes like earthquakes. The new design helped in cutting down the cost of the project by approximately $290 million. The initial cost of the project stood at about $500 million. The removal of the retractable roof helped in reducing the weight of the building holding the stadium. The other challenge they faced was that any increase in the weight of roof materials invariably exerts a lot of weight on the foundation of the structure.

The humongous pressure that is to be exerted on the foundation through roof erection is expected to be removed through elimination of the upper deck of the stadium being a significant quantity of weight together with the roof weight that may lead to instability of the structure. so They opted to do away with the retractable roof to enhance the stability of the stadium. They covered the roof with transparent materials in a bid to light the stadium .Nevertheless The Chinese managed to overcome the structural challenges during the construction of the Bird’s Nest Stadium.

CONCLUSION

The Bird’s Nest stadium is one of the most fascinating facilities in the world. Many people wish to go and see the stadium because of its unique construction. After the Olympics, few activities take place in the stadium, as such, the major source of revenue for the stadium are the tourists who come from different parts of the world to see the stadium.

More than 60 events are held in Beijing National Stadium every year, including sports events, equestrian performances, operas, and concerts.

The most anticipated events to be held there will be the opening and closing ceremonies of the 2022 Winter Olympics.

Author : Manikgoyal

REFERENCES

The Bird’s Nest Stadium

Written by Civil Engineering Consortium IIT Roorkee