China National Swimming Center of steel structure engineering

1. Basic information of the project>

Project location: Area B of the Olympic Park, southwest corner of the Olympic Center

Building area: 79532 ㎡

Building height: 31m

Structure type: steel concrete shear wall + steel structure + membrane structure

Commencement date: December 24, 2003

Completion date: January 26, 2008

2. Engineering Brief

The project is located in zone B of the Olympic Park and the southwest corner of the Olympic Center. The main building is close to the city's central axis, and is evenly arranged with the National Stadium relative to the central axis. The east side is Jingguan Road. The west side is Jingguan Road. The south side is close to Niangniang Temple of Beiding, and the north side is Chengfu road. The whole structure is cubic in shape, with a plane dimension of 176.538 × 176.538m and an above ground height of about 31m. The interior is mainly reinforced concrete structure, with a standard competition pool, a standard warm-up pool, a standard jumping pool and a water park of nearly 5000 m2.

3. Project features and difficulties

3.1 Important influence

The Olympic Games is the most important comprehensive event in the world. The 29th Olympic Games in 2008 is the first one with such international influence in our country. It is a major test to reflect the comprehensive strength of our country, especially Beijing. From the Party Central Committee and the State Council to the people of the country, great expectations are placed. The construction of hardware facilities is an important part of the preparation stage of the Olympic Games In particular, this new venue is the only one funded by compatriots from Hong Kong, Macao, Taiwan and overseas Chinese. Its significance is self-evident. As one of the main venues in the Olympic central area, the construction of the National Swimming Center has attracted the attention of the Chinese people and even the people of the world. The final quality of the construction will become the focus of the world.

3.2 characteristics of high-performance concrete: the durability design life of the concrete part of the project is 100 years, which must meet the requirements of long durability and good working performance of high-performance concrete from the selection of raw materials, construction process control, etc.

3.3 construction of swimming pools in accordance with the Olympic Games standards:

3.3.1 high standard quality requirements: the precision requirements of swimming pool and diving platform after finishing the decoration surface are higher than that of ordinary buildings, and more stringent than the national acceptance standards of ordinary buildings. In the construction process, every link related to the size of finished surface: measurement, selection and erection of formwork, pouring of concrete, completion of decoration surface, etc. must be strictly controlled to achieve the final accuracy requirements.

3.3.2 High waterproof requirements: the main functions of the project are swimming and diving. The main space of the building is the swimming pool. The impermeability of the swimming pool, that is, the concrete impermeability, crack resistance and waterproof materials are the key. From the mix design of concrete, the selection of waterproof agent, the selection of concrete pouring and maintenance process, the selection of flexible waterproof material manufacturers, etc., the scheme is reasonable and the field control is effective.

3.3.3 environmental protection requirements for the decoration of swimming pool: the interior of swimming pool is made of tiles, which must be water-resistant first, followed by the immersion of swimming pool water cleaning agent; the adhesive for sticking tiles must not fall off under the immersion of water, but also be harmless to people, and meet the environmental protection requirements. The selection of tiles, adhesives and construction quality control are crucial.

3.4 A new type of ductile polyhedron space rigid frame structure of roof and its supporting wall with abnormally complex structure

The building shape of the project is "cube filled with water". In order to reflect the design concept of different shapes of water droplets filling the whole space, the roof and supporting wall structure are composed of a ductile space rigid frame structure to form the skeleton of water droplets, and the two-layer frames inside and outside are respectively wrapped with ETFE membrane structure to show the flow state of water droplets. The irregular shape of the water drop determines the irregularity of the spatial change of the members of the rigid frame, which leads to the spatial diversity of the members of the rigid frame. There are about 6700t steel structures, 9843 joints and 20670 members in total, which put forward high requirements for fabrication, field measurement, installation, welding and unloading.

3.5 Large area membrane structure

The effect of the facade water of the project is realized by ETFE membrane structure, which reflects the actual indoor water surface. The expanded area of membrane structure is about 300000 m2, which is the largest membrane structure project in the world. It is also the only large-scale public building completely enclosed by membrane structure. It is a great challenge to the design, construction and use. It puts forward a very difficult subject for ETFE membrane materials, ventilation and air conditioning, fire prevention, sound, light, electricity control and other technologies.

3.6 Mechanical and electrical engineering with high standard and complex system

After the completion of the project, it must meet the strict requirements of the Olympic Games, and it will become the largest indoor multi-functional water entertainment, fitness and Sports Center in Beijing after the competition. The electromechanical engineering, especially the swimming pool equipment, lighting, power, air conditioning and other major systems must be guaranteed without any loss, especially the competition guarantee of a total of twenty weak current systems, in addition to the saving of materials and equipment High requirements are put forward for energy and environmental protection performance.

3.7 LED landscape lighting

As one of the important subjects of the national "863" plan, tens of thousands of LED lamps arranged in the roof and wall cavity can change 16.7 million colors based on red, green and blue. They are installed in the air pillow cavity on both sides of the south wall, 2000 square meters, the largest real-world display screen in Asia, which is independent combination of vertical model, ultra-high temperature resistance and high brightness, and perfectly linked with the membrane structure Together, "Water Cube" will present an unpredictable beauty.

3.8 A large number of new materials and processes are applied, among which there are many levels of interior decoration and serious cross operation

The interior decoration of the project is novel and unique, so many materials and processes are applied for the first time in China, which are relatively rare in the competition venues, such as 10000 ㎡ phenolic resin hanging board, 15000 ㎡ cast-in-place resin integral stone floor, 5000 ㎡ fiberglass sound-absorbing ceiling and wall, arc-shaped plating point anti glare glass package column, smoke curtain wall with space position changing at any time, etc. For example, from permanent and temporary stands to civil static pressure box, ceiling, toilet, overall stone and other civil structures, initial decoration, fine decoration, mechanical and electrical works, a total of more than 20 cross processes.

3.9 Design uncertainty

Taking into account the realization of the transformation functions during and after the games, the design not only needs the overall effect and the pursuit of perfection, but also conforms to the needs of the Olympic Games, and the needs of the Olympic Organizing Committee are constantly changing, resulting in a large number of design changes, especially since entering the decoration stage, the amount of changes is more than the sum of previous years, which brings great difficulties to the construction organization and quality control of the site.

3.10 There are many subcontractors and high requirements for the coordination ability of the general contractor

Due to the various construction functions, complex mechanical and electrical, and high requirements, the number of subcontractors of the project has reached more than 100, and there are some designated subcontractors of the Olympic Organizing Committee. How to make so many subcontractors subject to the unified coordination and management of the general contractor, so as to achieve the requirements of overall excellence, is a problem that must be solved.