The National Aquatics Center also has a unique name: Water Cube. "Water Cube", a crystal ball under the sun, has a unique structural design idea, which makes it have a unique visual effect. It is a great challenge for engineers to fully realize the architect's design idea. Mr James, ETFE project manager, said: "We have done a lot of visual tests to try to meet the architect's design concept. We think this is the biggest challenge. Now, we think it has been quite successful in this respect. " "Water Cube" is a square building with a height of 177 m by 177 m. The seemingly random building facade follows strict geometric rules, and there are 1 1 different shapes on the facade. Both the inner and outer floors are equipped with inflatable pillows, and the dreamy blue comes from the first membrane of the air pillow outside, because the curved surface reflects sunlight, making the surface of the whole building look like crystal water drops in the sunlight. And if you are in the "water cube", you will feel even more wonderful. When you enter the Water Cube, you will see it, just like bubbles in the marine environment. "Water Cube" and "Bird's Nest" are separated by only one road, one side is round, the other is blue, and the other is red, forming a delicate and balanced relationship. Mr. Zhao Xiaojun, the chief designer of China, said that as far as the design process is concerned, there is a "Bird's Nest" at first. Therefore, at the beginning of this design, how to form a harmonious, unified, contrasting and contrasting relationship with the "Bird's Nest" is an aspect that everyone pays close attention to. Wonderful, clean and dust-free. Green, healthy, harmonious and sustainable development are the most important architectural design concepts today. In the design process of "Water Cube", these ideas are always everywhere. "Water Cube" is an innovative building from architecture to structure, which contains high scientific and technological content. Its building envelope adopts new environmental protection and energy-saving ETFE membrane material, covering an area of 654.38+10,000 square meters. This is the largest ETFE application project in the world at present. Mr. James said, "This is a two-tier ETFE system, one outside and the other inside. From this perspective, it is the first and unique in the world. " The quality of this ETFE film material is only 1% of that of glass of the same size, with good toughness, more sunlight absorption and no spontaneous combustion. In addition, they also have wonderful self-cleaning function. "They don't stick to dust. As soon as the wind blows, the soil will go. " Mr. Kang Wei, general manager of the National Swimming Center, said. For a swimming pool, the heat demand of "smart bubble" reflective sunshade is greater than its cold demand, so the overall heat load should be considered at the beginning of engineering design. The crystal clear structural features of "Water Cube" can not only bring beautiful visual experience to people, but also have high practicability. Outside sunlight can directly enter the indoor heating swimming pool and indoor air. In summer, the "smart bubble" system of "Water Cube" realizes mutual ventilation of inner and outer bubbles by reflecting light spots with different directions and densities, which can change the shading coefficient, reduce its cooling load and achieve the purpose of low temperature. At the same time, the air conditioning system inside the Water Cube also fully considers the issues of energy saving and environmental protection. Engineering designers have realized the concepts of stratified air conditioning and district air conditioning, and reduced the energy consumption of air conditioning in water cube through technical means. Covering plan saves a lot of water. Beijing is a city short of water. The Water Cube with three huge swimming pools will evaporate more than one ton of water every hour. Is it possible to avoid this waste? In this regard, the builders of the "Water Cube" had careful consideration at the beginning of the design. They consider covering all the water in the swimming pool, that is, covering it with plastic sheets or other materials when the swimming pool is not used at night. The coverage scheme includes the entire "Water Cube" competition pool and water recreation hall. This can save a lot of water. In addition, another environmental protection function of the water cube is to collect and circulate rainwater, which is a technical highlight that fully embodies the water cube technology and green design concept. Rainwater falling on the roof of the Water Cube will be collected in the central storage tank under the building. These collected rainwater will be recycled. This is also fully considered in the "Bird's Nest" project. In particular, the acceptance criteria were formulated. The Water Cube is an innovative work in the architectural history of China, both in appearance and internal structure. And its construction process has also filled a series of gaps in national industries for engineers and technicians in China. Mr. Hou Bencai, executive manager of the National Swimming Center Project, said: "According to our previous construction practice, we all have standards to follow, that is, our country has either national standards, industry standards, local standards or at least enterprise standards. So now our project, steel structure, formwork structure, like all these related standards, don't know what to do. " In such a technical blank background, it is necessary for construction personnel to formulate a construction organization design outline before formal construction. After nearly 10 rounds of revision, many domestic experts finally determined this scheme. Including the processing, positioning, installation, welding and final unloading of steel structures, have been solved. In order to ensure the engineering quality, the acceptance standard of "Water Cube" is specially formulated. Mr. Hou Bencai said: "We have re-compiled a project acceptance standard with reference to some existing standards and combined with the characteristics of this project, which is completely aimed at the acceptance standard of the steel structure of the National Swimming Center. So I know how to do it and how to do it. This has also gone through a very tortuous process. " After the completion of the "Water Cube" project, the water recreation center after the Olympic Games will not only undertake the competition tasks, but also have many additional functions, such as water parks, fitness clubs and so on. Considering these long-term plans in advance will ensure that even after the 2008 Olympic Games, the "Water Cube" will still create considerable economic value.