Sensitivity Analysis Of Cable Force And Construction Control Parameters Of Long-span Hybrid Girder Cable-stayed Bridge

Cable-stayed bridge is a kind of complex structure with high stasis and stability.It mainly relies on the cable to provide vertical support to the main beam,and then the internal force is transferred by the cable to the main tower,and the main tower is transferred to the foundation of the bearing platform.The cable-stayed cable force has a great influence on the internal force distribution of the structure system and is crucial to control the force of the whole bridge.How to calculate and analyze the cable force of the cable-stayed bridge to improve the force of the cable-stayed bridge and how to adjust the cable force to achieve a reasonable bridge has become one of the most interesting problems in the design and construction technology of cable-stayed bridge.At present on the calculation method of cable in the industry has come up with a variety of relatively mature theories and methods,but most of the method has the applicable scope limitation,this paper takes the world's first asymmetric span hybrid girder cable-stayed bridge,charr changjiang river highway bridge as the engineering background,using the minimum energy method,stress balance method,the unknown load coefficient method to determine the reasonable into a completed bridge under dead load.First by changing the axial stiffness and bending stiffness for a carride out to calculate the initial state into a bridge,through the cable force to make,and further calculate the whole bridge under the action of load combination of the distribution of stress balance method to determine under the dead load bending moment feasible region,if the initial state of internal force does not meet the conditions by unknown load coefficient method to adjust into a completed bridge,eventually get reasonable into a completed bridge under dead load,to the reasonable state into a bridge.In this paper,the comparison of the calculation scheme of a falling frame is carried out,and the reasonable amount of stiffness increase or decrease is selected.At the same time,the effects of structural parameters such as the dead weight of beam section,the elastic modulus of cable,the elastic modulus of steel box girder,and so on the cable force and internal force of jiayu changjiang highway bridge are discussed respectively.