Extended data
I. Overview of Bird's Nest
The National Stadium (Bird's Nest) is the main stadium of the 29th Summer Olympic Games. Located in the central area of Beijing Olympic Park, it covers an area of 20.4 hectares and has a building area of 258,000 square meters, which can accommodate 9 1 1,000 spectators. The national stadium project is a super-class sports building, and the design service life of the main structure is 100 years. The main building is an oval bird's nest surrounded by a series of steel trusses, which is 333 meters long from north to south, 296 meters wide from east to west and 69 meters high at the highest point. The National Stadium was started on February 24th, 2003 and completed on June 28th, 2008.
The National Stadium is located on a pedestal platform that slopes slowly from the ground. Visitors can reach the stadium from the Olympic Park along the pedestal platform. The north side of the pedestal is a sunken warm-up venue, which is connected with the home competition venue through the athletes' passage. There are seven floors above the base of the stadium, with audience service facilities, media work area, VIP reception area and commercial area. There are three floors and zero-floor inner ring road, parking lot and a large number of functional rooms under the base. The bowl table is divided into upper, middle and lower floors, and the box and its seating area are set between the upper and middle floors.
Advanced energy-saving design and environmental protection measures have been adopted in the construction of the National Stadium, such as good natural ventilation and natural lighting, comprehensive rainwater recovery, utilization of renewable geothermal energy and application of solar photovoltaic power generation technology. It is a veritable large-scale "green building".
During the Beijing Olympic Games, the National Stadium, as the main venue, undertook the opening and closing ceremonies, track and field events, football finals and other activities. The wonderful opening and closing ceremonies complement each other with the magnificent structure of the Bird's Nest, which makes the world amazed. Bolt, Isinbayeva and other outstanding athletes have made record achievements in the Bird's Nest. After the Beijing Olympic Games, the Bird's Nest successfully hosted the 20 15 Beijing Athletics World Championships, and will also be the venue for the opening and closing ceremonies of the 2022 Beijing Winter Olympics. As the first stadium in history to host the opening and closing ceremonies of the Summer and Winter Olympic Games, the Bird's Nest has become a landmark building representing the national image, surpassing the simple concept of sports or architecture and being endowed with more sacred and profound social significance.
Second, the highlights of the Bird's Nest
1, and the building life can reach 100 years or more.
In order to make the "Bird's Nest" have a longer service life, the researchers also specially studied the crack resistance of the concrete used in the "Bird's Nest". After hundreds of tests, the service life of the "Bird's Nest" has been greatly improved by improving the carbonation resistance of concrete and increasing the thickness of protective layer. According to the test, the design service life of the main structure of the "Bird's Nest" has reached more than 1 0,000 years, and the local structure has even reached 1 0 for 20 years. The fire resistance rating is Grade I and the seismic fortification intensity is 8 degrees.
Clear broadcast can be heard in every corner.
More than 90 thousand people watch the game at the same time, and the live sound will be very noisy. If there is no good sound-absorbing material in the stadium, it will be difficult for both athletes and spectators to broadcast clearly. In addition to the PTFE membrane on the inner layer of the bird's nest, there are also sound-absorbing materials on the steel structure of the bird's nest. Through the high-performance electroacoustic amplification system in the Bird's Nest, the speech intelligibility index in the Bird's Nest can reach 0.6-this value can completely ensure that the audience sitting in any corner can clearly hear the live broadcast.
Any seat can enjoy the natural wind.
Because there is no fence, the "Bird's Nest" can let the wind circulate freely and ensure the transparency of the sports ground. After many demonstrations by designers, it borrowed a computer CFD simulation method in fluid mechanics design to simulate and analyze the thermal comfort and wind comfort of the audience, which can accurately simulate the natural ventilation of more than 90 thousand people watching the game at the same time. At present, all the ventilation facilities of the "Bird's Nest" are the result of adjusting and optimizing the drawings of foreign designers according to this simulation analysis. Whether the audience is sitting in the upper stand or the lower stand, ordinary seats or VIP seats, they can enjoy the natural light and wind.
References:
Baidu encyclopedia-bird's nest