The main body of the "Bird's Nest" is a combination of seismic wall structure and reinforced concrete frame. This brand-new structural system has the characteristics of high earthquake resistance, high safety and strong bearing capacity. Its external structure consists of 24 huge steel structure columns, which are triangular lattice columns with large upper end and small lower end. The highest pillar is in the east-west direction, 78 meters high, and the lowest pillar is in the north-south direction, 60 meters high. The thickness of steel for steel structure is 1 1 cm, and the total amount of steel for engineering design is 50,000 tons. The whole project has a unique shape, and there are a lot of curved structures in heavy steel structure, which has great challenges in steel quality, steel structure design, processing and installation. According to experts, the "Bird's Nest" is a large-scale steel structure project with the largest amount of steel, the largest scale, the most difficult construction and many world-class construction technical problems.
The "Bird's Nest" project is generally contracted by Beijing Urban Construction Group, and Beijing Urban Construction and Zhejiang Seiko Urban Construction Seiko and CITIC Guohua are subcontractors, each responsible for half of the "Bird's Nest" project.
Mamte Heavy Equipment Transportation and Installation Co., Ltd. undertook the hoisting of urban construction precision steel structures with a total hoisting capacity of 25,000 tons, with an average hoisting capacity of 1 15 tons every two days. Guan Xinyu, the manager of the company, introduced to us: "Mamt officially entered the" Bird's Nest "site in August 2005. The company is equipped with 800 tons of Demag CC4800 crawler crane, 600 tons of Demag CC2800 crane and 300 tons of Demag CC 1800 crane for hoisting, of which 300 tons of cranes have just entered the site and are still being assembled. The 800-ton crane is mainly used to hoist these columns, especially the upper part of the columns. After the upper and lower parts are docked, the workers start welding. "