Purpose–This study aims to research the development trend,research status,research results and existing problems of the steel–concrete composite joint of railway long-span hybrid girder cable-stayed bridge.Design/me...Purpose–This study aims to research the development trend,research status,research results and existing problems of the steel–concrete composite joint of railway long-span hybrid girder cable-stayed bridge.Design/methodology/approach–Based on the investigation and analysis of the development history,structure form,structural parameters,stress characteristics,shear connector stress state,force transmission mechanism,and fatigue performance,aiming at the steel–concrete composite joint of railway long-span hybrid girder cable-stayed bridge,the development trend,research status,research results and existing problems are expounded.Findings–The shear-compression composite joint has become the main form in practice,featuring shortened length and simplified structure.The length of composite joints between 1.5 and 3.0 m has no significant effect on the stress and force transmission laws of the main girder.The reasonable thickness of the bearing plate is 40–70 mm.The calculation theory and simplified calculation formula of the overall bearing capacity,the nonuniformity and distribution laws of the shear connector,the force transferring ratio of steel and concrete components,the fatigue failure mechanism and structural parameters effects are the focus of the research study.Originality/value–This study puts forward some suggestions and prospects for the structural design and theoretical research of the steel–concrete composite joint of railway long-span hybrid girder cable-stayed bridge.展开更多
The slab of the composite girder is usually very wide in composite cable-stayed bridges,and the main girder has an obvious shear lag.There is an axial force in the main girder due to cable forces,which changes the nor...The slab of the composite girder is usually very wide in composite cable-stayed bridges,and the main girder has an obvious shear lag.There is an axial force in the main girder due to cable forces,which changes the normal stress distribution of the composite girder and affects the shear lag.To investigate the shear lag in the twin I-shaped composite girder(TICG)of cable-stayed bridges,analytical solutions of TICGs under bending moment and axial force were derived by introducing the additional deflection into the longitudinal displacement function.A shear lag coefficient calculation method of the TICG based on additional deflection was proposed.Experiments with three load cases were conducted to simulate the main girder in cable-stayed bridges.And the stress,deflection,and shear lag coefficient obtained from the theoretical method considering additional deflection(TMAD)were verified by the experimental and finite element results.A generalized verification of a composite girder from existing references was made,indicating that the proposed method could provide more accurate results for the shear lag effect.展开更多
基金supported by the Key Project of Science and Technology R&DProgram of CHINA RAILWAY(AJZH2020-001)and Science and Technology Program Project of Shudao Investment Group(SRIG2020GG0001).On behalf of all authors,the corresponding author states that there is no conflict of interest.
文摘Purpose–This study aims to research the development trend,research status,research results and existing problems of the steel–concrete composite joint of railway long-span hybrid girder cable-stayed bridge.Design/methodology/approach–Based on the investigation and analysis of the development history,structure form,structural parameters,stress characteristics,shear connector stress state,force transmission mechanism,and fatigue performance,aiming at the steel–concrete composite joint of railway long-span hybrid girder cable-stayed bridge,the development trend,research status,research results and existing problems are expounded.Findings–The shear-compression composite joint has become the main form in practice,featuring shortened length and simplified structure.The length of composite joints between 1.5 and 3.0 m has no significant effect on the stress and force transmission laws of the main girder.The reasonable thickness of the bearing plate is 40–70 mm.The calculation theory and simplified calculation formula of the overall bearing capacity,the nonuniformity and distribution laws of the shear connector,the force transferring ratio of steel and concrete components,the fatigue failure mechanism and structural parameters effects are the focus of the research study.Originality/value–This study puts forward some suggestions and prospects for the structural design and theoretical research of the steel–concrete composite joint of railway long-span hybrid girder cable-stayed bridge.
基金supported by China National Ten Thousand Talents Program(No.W03020659)Shaanxi Key Science and Technology Innovation Team Project(No.2019TD-022)Special Support Plan for Key Research Directions of Green Highways in Central University Basic Research Business Fees of Chang'an University(No.300102219309).
文摘The slab of the composite girder is usually very wide in composite cable-stayed bridges,and the main girder has an obvious shear lag.There is an axial force in the main girder due to cable forces,which changes the normal stress distribution of the composite girder and affects the shear lag.To investigate the shear lag in the twin I-shaped composite girder(TICG)of cable-stayed bridges,analytical solutions of TICGs under bending moment and axial force were derived by introducing the additional deflection into the longitudinal displacement function.A shear lag coefficient calculation method of the TICG based on additional deflection was proposed.Experiments with three load cases were conducted to simulate the main girder in cable-stayed bridges.And the stress,deflection,and shear lag coefficient obtained from the theoretical method considering additional deflection(TMAD)were verified by the experimental and finite element results.A generalized verification of a composite girder from existing references was made,indicating that the proposed method could provide more accurate results for the shear lag effect.
