| The Bird's Nest, officially known as the National | | | | 36km of unwrapped steel length. |
| Stadium, caused quite a stir when it was unveiled | | | | How BIM helped |
| in 2008. It was both hated and loved, but for | | | | One of the most difficult parts of the building for |
| architects, engineers and construction workers | | | | the structural engineers was the roof. The |
| around the world, it inspired another emotion - | | | | enormous weight of the steel showed in their |
| awe. This project was enormously detailed, and | | | | calculations that a full steel roof was simply not |
| could not have been achieved in as short a time, | | | | possible. It took over a year for Chinese steel |
| with as low costs and little room for error, had it | | | | detailers and fabricators (two firms - Huning and |
| not been for building information modelling | | | | Jinggong) to produce symmetrical 3D views of |
| technology. We look at how BIM made it possible | | | | the connections and members. Good building |
| for the structural engineers, steel detailers and | | | | information modelling software has mirroring |
| construction team to put the Bird's Nest together | | | | functions, which took a lot of the legwork out of |
| in time for the Olympics. | | | | this project. The connections are almost |
| Vital statistics for the Bird's Nest | | | | impossible to visualize mentally - but this is not |
| * 332m long, 297m wide, 69m high | | | | required, with the advent of 3D modelling for |
| * Site area: 204,278 sq. m. | | | | construction. |
| * Structure contains 36km of unwrapped steel | | | | Another of the Bird's Nest's major features that |
| length | | | | would not have been possible without BIM is the |
| * Largest steel truss spans 343m | | | | cushion system of the inner spaces of the |
| The Bird's Nest Challenges | | | | building's facade. It was not only support that had |
| To some people it might look like a tangled ball of | | | | to be considered in the design; the structural |
| discarded wire. To the people that built it, there | | | | engineers used building information modelling to |
| was much more involved than finding leftovers. | | | | predict how the structure would react to wind, |
| Some of the issues that building information | | | | sunlight and weather. The solution ended up being |
| modelling helped solve quickly for the structural | | | | to fill some spaces strategically with ETFE, a |
| engineers and steel detailers included: | | | | translucent material used to construct the 'Bubble |
| * Weight minimization | | | | Building' also in the Chinese Olympic Park. |
| * Reducing construction costs | | | | Obviously, the appearance of the building is it's |
| * The saddle-shaped, ellipse based roof | | | | most important factor. It is different, unusual and |
| * An outward incline of the external surface of 13 | | | | culturally significant; as well it is 'anti-technocratic' |
| degrees from vertical | | | | (according to the designers). This would not have |
| * As you see in the vital statistics, the largest | | | | been possible without the aid of building |
| steel beam is 343m long, and the structure used | | | | information modelling. |