On Mid-span Closing Of Long-span Cable-stayed Bridge Construction Control Research

With increasing cable-stayed bridge, the construction control in construction process of the increasingly significant position. For long-span cable-stayed bridge construction control, mid-span closing most important. With the case study of Jingyue Yangtze River Highway Bridge, based on the self-adaptive stress-free thought,put forward a kind of new technology on mid-span closing of long-span cable-stayed bridges construction control.This thesis employed new closing technique, analyzed and commented in an exhaustive way on the construction control process of long-span cable-stayed bridges. The main contents of this thesis are as follows:1. Through BDCMS system, this thesis elaborated the influence on the bridge linearity and internal force by geometry nonlinearity under the circumstance of Jingyue Yangtze River Highway Bridge with longest cantilever and temporary constraint-free tower beam after mid-span closing. It also expounded on the importance of geometry nonlinearity theory in calculation and analysis for the construction control of long-span cable-stayed bridges with composition beam.2. A new method– seaming close was raised for mid-span closing construction control of long-span cable-stayed bridges, the fundamental principle and strengths of which were presented explicitly in the thesis. The vital technology of adopting this method in were also pointed out. It was successfully used in the construction control of the mid-span closing for Jingyue Yangtze River Highway Bridge and received satisfying result.3. With the case study of Jingyue Yangtze River Highway Bridge, the thesis analyzed before closure the importance of the cantilever construction on the bridge's linearity and internal force for mid-span closing;longest cantilever the influence of the temperature of change theoretical calculation and analysis;the thesis explicitly researched on the precise positioning control method for longest cantilever and the length calculation of the mid-span cantilevering in the last section.4. The thesis explained the significance of the adequate traction force to the mid-span closing of unsymmetrical long-span cable-stayed bridges, analyzed accurately the interaction between tractive distance and force, and introduced the technique and controlling method of the adequate unilateral tractive force before mid-span closing of the unsymmetrical cable-stayed bridges. 5. Calculated of Jingyue Yangtze River Highway Bridge closing and system conversion the influence of temperature variation to finally into bridge.