As one of the three main venues of the Beijing Olympic Games, the construction of the National Stadium officially started on May 28th, 2005, and was completed and accepted at the end of June 2007 1 1. The National Gymnasium will mainly undertake competitive gymnastics, trampoline and handball during the Olympic Games. After the Olympic Games, the National Gymnasium, as a first-class sports facility in Beijing, will become a civic activity center integrating sports competitions, culture and entertainment and providing multi-functional services. The project is mainly composed of the main building of the gymnasium, the warm-up hall adjacent to it and the corresponding outdoor environment. It covers a total area of 6.87 hectares and a total construction area of 80,900 square meters, which can accommodate 1.8 million people. "Good Luck Beijing" 2007 Gymnastics International Invitational Tournament will be held at the National Gymnasium on/kloc-0 from October 28th to February 3rd. Date: May 28th, 2005 The National Gymnasium Project officially started on May 28th. Member the Political Bureau of the Communist Party of China (CPC) Central Committee, Secretary of Beijing Municipal Committee, Chairman of the Organizing Committee for the 29th Olympic Games Liu Qi, Mayor of Beijing, Executive Chairman of the Organizing Committee for the 29th Olympic Games Wang Qishan and other city leaders attended the groundbreaking ceremony. Inspired by China's folding fan, the National Gymnasium fully embodies the Olympic concept of "Green Olympics, High-tech Olympics and People's Olympics" and the principle of "frugal Olympics", and pays attention to the combination of functional design, environmental protection design and aesthetic design, which embodies the design principles of function first, technology first, meeting the competition, abiding by norms, energy saving and environmental protection, and post-competition utilization. The owner of the National Stadium is Guoao Investment and Development Co., Ltd., a project legal person generated through global public bidding, responsible for the investment, construction and operation of the entire National Stadium. The design unit of this project is Beijing Architectural Design and Research Institute, the construction unit is Beijing Urban Construction Group Co., Ltd., and the supervision unit is Beijing Construction Engineering Jingjing Dafang Engineering Construction Supervision Company. Since construction started in May 2005, this Olympic competition venue (gymnastics, trampoline and handball finals) located in the south of the central area of Beijing Olympic Park has gradually completed the installation of I-beams with overhangs on the east and west facades, the pouring of the main structure and stands, and the sliding of the steel roof truss. Humanized and environmentally friendly design has become the biggest highlight, and the quietest venues are everywhere. After the Olympic Games, the National Gymnasium will be the most advanced indoor gymnasium in Beijing, with the leading function of organizing various international and domestic professional sports events and large-scale sports cultural and commercial performances. The multifunctional composite roof solves the problem of raindrop noise on the roof and reduces the interference to the normal use of the gymnasium. The roof adopts nine-story composite structure, which is rare in China. It consists of cement board, glass wool, waterproof layer and sound-absorbing and sound-insulating materials, and the outermost layer is sprayed with sound-absorbing materials to minimize the impact of outdoor noise. The glass curtain wall around the venue is a combination of hollow Low-E glass and metal plate, all of which are made of double glass. The gap between the two layers of glass is filled with argon, which not only plays a good role in heat insulation, but also effectively reduces the influence of noise. The air-conditioning and refrigeration equipment in the venue has also undergone special noise reduction design, and the road to stroll through the Olympic Village is paved with scrap steel accumulated by Shougang. The buried depth of the basement is about 8 meters, and the anti-floating water level is negative 1 m, which requires a large capacity of materials to resist floating and compression. If natural sand and gravel are used, it needs at least 80,000 tons. 3 million tons of steel slag accumulated by Shougang was adopted, which saved energy. It is convenient for disabled people to enter the gymnasium. Just north of the auditorium is a platform of more than 300 square meters, which is the "golden position" in the museum from both angle and height, but there is no seat. This is a wheelchair support specially prepared for the disabled. In the National Gymnasium, disabled friends who use wheelchairs can go directly to the wheelchair stands through gentle slopes or six elevators for the disabled. Disabled spectators can watch the game in wheelchairs. The whole area can accommodate about 120 disabled people in wheelchairs.