Commonly known as: Bird's Nest

English address: National Stadium (Bird's Nest)

Venue: Beijing Olympic Park

Building area: 258,000 square meters

Fixed number of seats: 80,000

Number of temporary seats: 1 1000

Function: To hold the opening and closing ceremonies of the Olympic and Paralympic Games.

Games-time functions: track and field, men's football

Post-game functions: used for international and domestic sports competitions, cultural and recreational activities, and public fitness.

Commencement time: 2003. 12.24

Completion time: June 28, 2008

Cost: USD 450 million (RMB 36,543.8+0 billion)

General introduction

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Located in the south of the central area of Beijing Olympic Park, the National Stadium is the main stadium of the 29th Olympic Games in 2008. The project covers an area of 2 1 hectare with a building area of 258,000 ㎡. There are about 9 1000 seats for the spectators in the venue, including about 1 1000 temporary seats. The opening and closing ceremonies, track and field competitions and football finals of the Olympic and Paralympic Games will be held. After the Olympic Games, it will become a large-scale professional place for Beijing citizens to participate in sports activities and enjoy sports entertainment, and become a landmark sports building and Olympic heritage.

The National Stadium is a super-Grade A sports building, with the designed service life of the main structure of 100 years, fire resistance grade I, seismic fortification intensity of 8 degrees, and underground engineering waterproof grade of 1. The main building of the project is a space saddle oval with a length of 333 meters from north to south, a width of 294 meters from east to west and a height of 69 meters. The main steel structure forms a "bird's nest" structure woven by saddle-shaped steel truss in the whole giant space. The total steel consumption of steel structure is 42,000 tons. The concrete stands are divided into upper, middle and lower floors. The concrete structure of the stand is a reinforced concrete frame-shear wall structure system, with 7 floors underground 1 floor and above ground. The steel structure and the upper part of the concrete stand are completely separated, and they are not connected with each other, but are enclosed in form, and the foundation sits on the connected foundation plate. The roof steel structure of the National Stadium adopts a double-layer membrane structure, that is, a transparent upper ETFE membrane fixed between the upper chords of the steel structure and a translucent lower PTFE sound-absorbing ceiling fixed under the lower chords of the steel structure and the inner ring side wall.

The national stadium project adopts PPP (private+public+partnership) mode, and the project company is jointly established by Beijing State-owned Assets Management Co., Ltd. and China CITIC Group Consortium, which is mainly responsible for the investment, financing, construction, operation and management of the national stadium. CITIC Consortium contributed 42%, and Beijing State-owned Assets Management Co., Ltd. gave 58% financial support on behalf of the government. CITIC Consortium also owns the franchise right for 30 years after the Olympic Games.

As a national landmark, the National Stadium Project is the main stadium of the 2008 Olympic Games. Its structural characteristics are very obvious, and the structure of the National Stadium is complex.

There are many characteristics and difficulties in design and construction:

1. The components are large in size and heavy in weight.

As the main load-bearing component of the roof structure, the truss column has a maximum section of 25m×20m, a height of 67m and a maximum weight of 500 tons. However, the height of the main truss is 12m, the maximum span of the double-span truss is145.577+12.788m, and the maximum span of the non-span truss is 102.95438+0m. Truss columns and main trusses are bulky and heavy.

2. Nodes are complex

Because all the members of this project are box-section members, there is a phenomenon that multiple members intersect in space, whether between the main structures or between the primary and secondary structures. In addition, the secondary structure is complex and changeable, and the regularity is less, which leads to the complex node structure of the main structure, diverse node types and high manufacturing and installation accuracy requirements.

3. The construction period is tight

The engineering quantity of this project is large, but the installation period is quite short. The project started on February 24th, 2003 and is expected to be completed by the end of 2007 and March 2008. The construction period is tight, overlapping with civil works, and the plane site is tense.

4, the welding quantity is large

The site connection of this project is divided into multi-section welding and hoisting, and the site weld length is long. In addition, thick plate welding, high strength steel welding, steel casting welding, etc. Majority, resulting in considerable workload, high difficulty and high-altitude welding.

5, winter rainy season construction

The hoisting time of the main structure of this project needs to span winter and Spring Festival, and it is difficult to construct in winter and rainy season.