Analysis On Static Dynamic Performance And Towers Ultimate Bearing Capacity Of Long-Span Cable-Stayed Bridge With Single-Pillar Steel Towers And Detached Steel Box Girders

At present,there are fewer large-span cable-stayed bridges with steel bridge towers in China,and the current relevant specifications do not make clear requirements for their mechanics and stability-related structures,and there are fewer related studies,which have brought certain difficulties to the design of steel bridge towers.Taking a one-column all-steel structure bridge tower highway long-span cable-stayed bridge as the research object,the thesis calculates and analyzes the force and deformation of the main components of the bridge under the construction stage,operation stage and seismic action,the stability performance of the steel bridge tower is also studied in detail.The main work of the thesis is as follows:(1)The development history,structural characteristics and application status of the split steel box girder cable-stayed bridge are briefly introduced,and the stability of the steel bridge tower is proposed according to the development history and force characteristics of the steel bridge tower.(2)The whole bridge model based on beam elements is established by MIDAS/CIVIL,the force and deformation of the bridge structure in each stage of construction are calculated and analyzed.According to the relevant specifications,the load conditions are combined and the force performance of each component of the bridge during the operational phase are checked.Considering the pile-soil interaction,the response of bridge structure under seismic action is calculated by using response spectrum and linear time history methods,in which the correlation between the two methods is compared and analyzed.(3)The thesis introduces the analysis theory and method of structural stability in the first and second categories,the evaluation basis of the stability of the cable-stayed bridges is also given.Based on the established model of full bridge elements,the overall stability analysis of linear and geometric nonlinearity in the operation stage of the steel bridge tower is carried out,and the limit carrying capacity is calculated by layer-by-layer yield method of layer by layer beam unit.Using the ABAQUS software to establish the whole bridge model of shell and beam hybrid element to calculate and analyze the linear and nonlinear stability of the bridge tower in the operation stage.The stability performance of the steel bridge tower was compared and analyzed under the two models,the stability performance of the steel bridge tower was also evaluated.