The Civil Engineering Contractor March 2019 | Page 20

THIS IS CIVIL ENGINEERING This extraordinary structure required new methods to calculate and fabricate steel sections to reduce the weight of the structure. To lower construction costs, the designers eliminated the upper roof and enlarged its opening. In this way, the total weight of the structure could be reduced to 3 000 tonnes. The interlaced steel structure covering the stadium gives it a ‘light’ feel and a ‘bird’s nest’ look. This stadium was designed and built to resist major earthquakes. The building is set on 37 metres of piling capable of supporting the horizontal forces of the structure. The injection method (inserting concrete into the core of the piling) was employed to strengthen the ground around the building. Finally, the roof, weighing more than 11 000 tonnes, is supported by the building structure. It is one of the largest steel structures in the world. It is covered with a polymer membrane to enhance lighting in the stadium while minimising glare and shadow. Beijing's Bird's Nest Olympic Stadium. 18 | CEC March 2019 www.civilsonline.co.za