Using chaos to create order
In the Beijing heat, the Olympic Green looks like a summer nesting ground for construction cranes. It's as if an entire nation's infrastructure has headed north to realise the massive undertaking of building and upgrading the dozens of competition venues needed to stage the Greatest Show on Earth.
Two-and-a-half years into the building programme, the main arena, the National Stadium, has already taken on much of its distinctive bird's nest shape and organisers say about 80 per cent of the steel structure for the design has been welded into place.
Up close, it's monumental - the steel box 'twigs' dwarf workers and their angle grinders.
Zhang Hengli, deputy general manager of the National Stadium Company, says the 3.13 billion yuan project is on budget and scheduled to be completed by the end of next year, leaving eight months for testing and commissioning before the event's opening ceremony.
Zhang says the internal structure is almost finished and work on the steel exoskeleton and its 36km of unwrapped metal will be completed this year. To meet the deadline, about 2,000 workers are labouring at the site in eight-hour shifts, around the clock 'at critical stages'.
The building was designed by Swiss architects Herzog and De Meuron in collaboration with China's Institute of Architecture Design and Research and Zhang says it has been a major engineering challenge to bring the 'beautiful' architectural drawings to life.
'We had to develop new technology and construction methods,' he said. 'It's not easy manufacturing according to this shape. In the factory, [it was] very difficult.'
The National Stadium is one of three venues at the Olympic Green to be built from scratch and another, the National Aquatics Centre, is within eyesight. The two sites are separated by mountains of excavated earth and a warren of temporary offices and construction-crew housing.
The centre will host the swimming, diving, water polo and synchronised swimming competitions and is the creative offspring of a partnership involving PTW Architects and Ove Arup, the China State Construction Engineering Corporation and the CSCEC Shenzhen Design Institute. Although geometrically imprecise, it has been dubbed the 'Water Cube' and plays on the idea of bubbles.
Most of the building is still under wraps but part of the cube's scaffolding has been peeled away to expose some of its honeycomb of steel and the thousands of knots tying the edifice together. The steel lattice has been locked in place and workers are preparing to instal two layers of cushions made from a lightweight material called ETFE, which will form the building's walls and roof. ETFE is a modified fluoropolymer which combines superior mechanical toughness with great chemical inertness.
Wang Wubin, the deputy general manager of the aquatics centre project, said that once the building's design was finalised, the project was divided into 11 engineering 'topics' to tackle its construction.
'We expected to have some problems with new materials,' Wang said. '[That's why we had] 11 topics to resolve these questions after design.
'It's the largest ETFE project in the world. [The material] is transparent, lightweight and energy saving. The sound effect is good for broadcasting.'
Wang says about 100,000 welding lines on the steel structure have been checked several times for cracks and installation tests on the structure were positive. 'The final results are better than we expected,' he said.
'By the end of October 2007, the whole project will be ready for testing and commissioning,' Wang said.
