A century ago, lasted three days and three nights the fire almost the entire Chicago to ashes. Americans, however, take this opportunity to ignite the torch of architectural art. Materials of glass and steel building which over the country, even the chain stores became steel ...
According to the statistics, until the mid-1980s, China's steel construction has just had "zero" breakthrough. Although a late start, China's steel construction, a high starting point, have developed rapidly. Today, it comes to building made by the representatives of the people perhaps will immediately think of the "Bird's Nest", the new CCTV building, Guangzhou TV Tower, Shanghai World Center ... Looking at cities around the building, almost all tall towering landmark in architectural form selected steel.
The starting point of Chinese steel structure construction can be traced back to the construction of three successful first steel building in China - Shenzhen Development Centre in 1984. Concrete structure as the main form of domestic construction field, which regarded as a virgin land. At that time, the council selected 10 the welder elite went to Japan to learn the world's most advanced carbon dioxide gas shielded welding technology. Japanese experts learned that most of them only a junior middle school education, had used humiliation tone asserts that "they can have one-third of qualified good, because They culture the basis of a solid 3-6 also have to learn Chinese workers only one month of the contract period of study. 10 Chinese welders daily concentrated study of seven hours, after school after a meal to explore, learn from each other, all successfully closed down after 30 days, a solid understanding of the welding unique skills necessary to complete the Shenzhen Development Center Building Project. In the construction, refresh the previous record of 110 mm from the welding thickness of 130 mm to 350 000 linear meters of weld by ultrasonic and powder AIDS testing and inspection are all qualified, and then 98% of welding to achieve the highest (level) ... in China the development of steel structure construction technology has now entered the fast lane, technical support, the steel skyscraper in the land of China and as springing up like Vietnam to build more and more made the higher.
Steel structure is now more popular, and its shape and construction of more and more difficult, such as public buildings in the country representative of the CCTV new site project, both a high degree of difficulty, irregular building structure construction of a challenge; Guangzhou TV Tower, the tower structure is very complex, and more complex steel structure construction; the "Bird's Nest" can be said is the singular form of masterpiece. "CCTV", for example, the tilt (overall two-way tilt degrees) and double (70 m and 60 m) structure, and double oblique direction of the structure under the action of gravity will have some sag; the level of the steel used in the general steel construction mostly Q345D or the Q390D, "CCTV" project uses Q420D and Q460D, which is rare in the general public buildings, has brought a lot of technical difficulty and requirements to the production of steel and welding; two towers and the 14-storey cantilevered structure connected to form a huge "door" shape, the traditional construction technology constitutes a daunting challenge. cantilever sagging under the force of gravity, the requirements in the construction process to be anti-deformation requirements of the steel structure during the welding process need to calculate the presetting value that the public in the past the Jianzhong almost less than; In addition, engineering measurement is difficult, due to structural tilting, resulting in the the each Genzhu positioned in the high altitude, plus pre-tune the value of its the difficulty of the installation will be greater; improve with the level of steel, its thickness increased to 135 mm long extra-thick steel welding project.
The characteristics of the steel structure in the "Bird's Nest" is a space curve structure, lead to higher requirements for the production of steel structures, because once there had been errors between the welded steel structure is difficult to butt smooth, another welding process is also relatively more stringent requirements; Yintai Center construction, the biggest difficulty is assembled on the ground, two 39 m long truss, and then use the crane hoisting. Ouyang said the ultra-high-rise steel buildings, involving the use of large span, long welding and construction technology.
Steel construction in the future direction of development in the ultra-high-rise, large span, and the special shape of the three. The special shape of the Guangzhou TV Tower and the "CCTV", "nest" as the representative of these buildings have in common is concrete construction. Architectural forms such as capital, Wuhan, Baiyun Airport, as well as some of the modern railway station to the space curve is connected to the span direction, this structure can only be done by the steel structure in the form. In addition, the steel level is getting higher and higher, the steel construction will also be increasing the amount of steel.
