Analysis Of The Mechanical Properties In Construction Process And Nonlinear Influence Of Steel-concrete Composite Cable-stayed Bridge

The upper structure of cable-stayed bridge consists of 3 main components,the main beam,the stay-cable and the main tower.The characteristic of this type of bridge is that the main girder is subjected to bending and compression,and the bracing system is mainly subjected to tension of cables and compression of main tower.Because of the complexity of the structure system and the variety of materials,the disadvantage of the bridge during construction and use is more serious.At the same time,with the increase of span length of cable-stayed bridge and the understanding of the stress and deformation properties of new materials has been deepened,the development of computing ability and the numerical calculation method of the continuous improvement of the effect of nonlinearity of cable-stayed bridge gradually caused by engineering and technical personnel attention.So accurate analysis of static responses of long-span cable-stayed bridges under various conditions,designing and constructing the cable-stayed bridge rationally need reasonable computational analysis.So that the design and construction of cable-stayed bridges are scientific,reasonable,safe and reliable.Steel-concrete composite cable-stayed bridge is a large span bridge,which based on playing full material advantage of steel and concrete in 80 s.In this paper,based on the engineering background of Jiangxi Zhangshu Ganjiang Bridge.The development history and current situation of cable-stayed bridges at home and abroad are considered,and 3 main research contents are presented.(1)Through the bridge engineering software Midas and civil,the construction stage and the finite element model of the completed bridge are established respectively;(2)The geometric deformation and internal force distribution at the construction stage and the completion stage are analyzed,and the stress characteristics of the composite beam under the multi statically indeterminate structure of the cable-stayed bridge are explored;(3)Based on the finite element model of the completed bridge,the influence of geometric,material nonlinearity and shear key characteristics of composite beam on the stress of the structure under the statically indeterminate cable-stayed bridge is investigated.The conclusions are as follows:(1)In the process of construction,due to the transformation of the force system and the application of the secondary dead load,the deflection of the main beam and the horizontal displacement of the main tower are increased.(2)The shear stiffness of shear connectors in composite beams decreases,causing the load on the main beam more seriously.Change the connection arrangement,the main influence in bending moment.(3)The sag effect and the large displacement effect have little influence on the deformation of the main beam.At the same time,the influence is not nonlinear.