The application of computer aided shape simulation technique in steel tower segment fabrication of Nanjing 3rd Yangtze River Bridge

Nanjing Yangtze river 3rd bridge is the first bridge that uses the steel structure as the main tower in China. The inclination of the steel tower has a great influence on the security of the whole bridge. Because of the big size, the steel tower had to be divided to 22 segments in factory and erected segment by segment bridge site. Because of the connection mode of the segments, the shape of the steel tower can not be adjusted during erection and the fabrication error of each segment will be accumulated and propagated during erection. Accordingly, high precision of the mechanical cutting of each segment end face was required and the fabrication error of each segment must be strictly controlled. In this paper, we gave the computer aided shape simulation technique aiming at the precision evaluation and control of segment fabrication of the steel tower. The technique has been applied successfully to the construction of Nanjing 3rd Yangtze river bridge.