Analysis Of Internal Force Behavior Of Steel-concrete Joint Section Of Mixed Beam Of Cable-stayed Bridge With Special-shaped Pylon

With the development of the construction technology of cable-stayed bridges at home and abroad,the cable-stayed bridge with special-shaped cable towers gradually enters people’s field of vision.It attracts people’s attention with its unique shape.The main beams of special-shaped cable-stayed cable-stayed bridges mostly use hybrid beams.The structural details and design of the steel-concrete joint section of each hybrid beam cable-stayed bridge are not the same.At present,there is no proposal for the structural design of steel-concrete joint section。The analysis of the interaction between the shear bond,the steel plate and the concrete and the internal force distribution in the joint section are of great significance for the study of the internal force transmission path in the joint section.Based on the domestic and foreign research results of the steel-concrete joint section of the main beam of the cable-stayed bridge with special-shaped cable tower,the analysis results of the finite element software and the measured data are compared.The results show that the analysis results of the finite element software are in good agreement with the measured data.The correct and reasonable finite element model can accurately reflect the stress state of the joint section,and the rationality of the design of the steel-concrete joint section of the real bridge is evaluated based on the measured data and the finite element calculation results.The research content and conclusions are as follows:1.According to the construction process of the cable-stayed bridge on site,the finite element software MIDAS CIVIL is used to model and analyze the overall cable-stayed bridge.At the same time,the measured data were collated and the cable force value of the cable stay and the stress value of the main beam were compared.The comparison results show that the analysis results of the finite element software are in good agreement with the measured data,which ensures the validity and accuracy of the calculation results of the finite element model.After determining the reasonable state of the bridge,compare the cable force optimization methods of the stay cable and at the same time consider the construction technology of the main beam,and select the cable force optimization method suitable for the system bridge to optimize the cable force.2.The solid simulation software MIDAS FEA is used to analyze the local modeling of the steel-concrete joint section of the main beam.When considering the static load effect,the internal force size and distribution of the steel cell and concrete beam in the steel-concrete joint section were analyzed.The measured stress data confirms the accuracy of the calculation results of the volume simulation software.3.Analyze the characteristics of different construction techniques of the main beam,and consider the influence of different main beam construction techniques on the internal force of the steel-concrete joint section.This article takes the cantilever method and the bracket method for the construction of the main beam as an example to compare and analyze the effects of different main beam construction techniques on the internal force size and distribution of the steel-concrete joint section.4.The finite element software MIDAS CIVIL is used to model and calculate the cable-stayed bridge.The internal force of the steel-concrete joint section of the main beam during the tensioning of each group of cable-stayed cables was analyzed.Determine the maximum and minimum internal forces of the joint section during the tensioning of the cable stay,and use the solid simulation software MIDAS FEA to locally model and analyze the steel-concrete joint section of the main beam to determine the process of the cable staying.Changes in the size and distribution of the internal force in the steel-concrete joint section,analyze the internal force transmission path,and determine the internal force transmission ratio of each member in the joint section at different positions.The mixed beam cable-stayed bridge fully exerts the tensile properties of steel and compressive properties of concrete,which greatly improves the mechanical properties of the structure.Taking the steel-concrete joint section of the main beam of a special-shaped cable-stayed cable-stayed bridge as the research background,the numerical analysis and the comparison of measured data are used to analyze and study the cable force optimization of the cable stay,the different construction methods of the main beam and the inclined.The influence of the tension of the cable on the stress of the steel-concrete joint section can provide a research reference for the research of the steel-concrete joint section of the main beam of the similarly shaped cable-stayed cable-stayed bridge.