Analysis Of Four Cable Planes And Separated Steel Box Girder Cable-Stayed Bridge Load Transverse Distribution

Taking the Wuhu Yangtze River Highway Bridge as engineering background, in close connection with the four cable planes, separated steel box girders, and rotary cable saddle structure characteristics and spatial effect obvious problems, this paper focus on problems of separated steel box girder transverse load distribution and cable force transverse distribution, to establish simplified calculation method of transverse load distribution for this separated steel box girder cable stayed bridge. Stress distribution of anchorage zone is analysized to verify the advantages of rotating in the same direction saddle anchor system. The four cable plane force transverse distribution is calculated and analyzed to obtain the features of cable force transverse distribution. The research not only can verify the rationality and safety of design for Wuhu Yangtze River Highway Bridge, but also can provide reference for similar bridge design.The main work and conclusions are as follows:1. Selecting eccentric-compressive method and modified eccentric-compressive method as simplified algorithm of Wuhu Yangtze River Highway bridge load transverse distribution, the key parameters of the two methods are firstly calculated. Then, load distribution influence line and the partial load coefficien are calculated by the spatial finite element method and simplified calculation method to verify the simplified algorithm. The results indicate that the result of modified eccentric-compressive method is in good agreement with that of finite element method. Therefore, the modified eccentric-compressive method can be used to calculate the load transversal distribution factors of separated steel box girders cabled-stayed bridge as a simplified method.2. Parameters analysis of transverse load distribution is conducted for the Wuhu Yangtze River Highway Bridge separated steel box girders. It can be concluded that:the greater rigidity of the stay cables, the bigger slope of the influence line of the transversal distribution factors as well as the eccentric-loaded coefficients; the bigger torsional stiffness of the girder, the smaller slope of the influence line of the transversal distribution factors as well as the eccentric-loaded coefficients; changing the stiffness of the beam will not signally affect the load transversal distribution factor; in axial direction of the bridge, the shorter distance with the tower, the bigger slope of the influence line of the transversal distribution factors as well as the eccentric-loaded coefficients.3. Segment model of cable-tower anchorage zone is established. Stress calculation results indicate:tensile stress of anchorage zone is mainly distributed around the anchorage zone, and tensile stress value is small; the compressive stress is mainly distributed in both sides of the tower, and it is also in the safe range. This verifies the advantages of the rotary saddle anchor cable system.4. Through the finite element model, we calculate the increment of cable force of each single cable plane under the partial live load. Then we compare the calculation results from the point of view of force and stress. The results show that the four cable plane cable force is uniformly distributed in the horizontal, which indicates the reasonable four cable surface design for Wuhu Yangtze River Highway Bridge.