Study On Mechanical Behavior Of Asymmetric V-tower Cable-stayed Bridge

For modern urban bridges,people’s requirements are not only limited to their basic traffic functions,but also landscape functions,which can be coordinated with the city’s history,culture and environment.Obviously,the traditional bridge type can’t meet people’s pursuit of aesthetics.Since 2008,the first V-shaped tower cable-stayed bridge in China,Shenyang Hunhe Sanhao bridge,has been built.The V-shaped tower cable-stayed bridge based on the arch bridge tower is convenient As the times require,the two towers of v-tower cable-stayed bridge are V-shaped in space,with novel and beautiful shape.Each pair of stay cables of the structure is composed of one horizontal cable and two stay cables.Three stay cables form a relatively balanced force transmission system,which makes the structure and stress of v-tower cable-stayed bridge relatively complex.At present,there is no in-depth study on its force transmission mechanism and stress characteristics.This paper mainly includes the following points:(1)In view of the structural form of asymmetric V-shaped tower cable-stayed bridge,this paper discusses the main tower main girder connection and main arch main girder connection respectively,and combines four relatively reasonable structural systems,analyzes the structural stress and deformation of these four structural systems under the action of dead load,live load and temperature,and analyzes the stability of each structural system,and comprehensively compares various structures According to the advantages and disadvantages of the structural system,the structural system type which is better for the cable-stayed bridge is selected,and the following research is carried out for the optimal system.(2)Under the live load response,the sensitivity analysis is carried out for the stiffness parameters of each part of the two optimized systems(system I and system III),including the main girder,the bridge tower(main tower and arch),and the stay cable(middle cable and side cable).At the same time,the influence degree of the stiffness change of each part on the stress of the whole bridge structure is obtained through the rule summary of the influence factor K;based on the influence factors The main research factors are determined by sub analysis,and then the orthogonal test scheme is determined.The range method is used to optimize the parameters of the original design scheme(system I)of the engineering background in this paper.(3)FEA solid finite element model is established for the main tower and main arch of the bridge.Based on the main tower model,taking the length of different sections of the main beam as the influencing factors,the size effect is studied.The detailed spatial stress analysis is carried out for the main arch and main tower,and a series of reasonable suggestions are put forward for the improvement of the stress condition.(4)The FEA finite element model of the main tower and the main arch is used to compare the stress conditions of system I and system III,and the advantages and disadvantages of the two systems are analyzed.Taking the thickness of stiffener,diaphragm and arch wall of the steel arch tower as the influence parameters,the influence of the thickness of each part on the longitudinal and transverse stress laws of the steel arch tower is explored.