Effect Of Separation On The Stastic And Dynamic Performance Of Of Concrete-filled Steel Tube Arch Bridge

Because of its merits of high carrying capacity, upstanding plasticity and toughness,construction convenience, better economic effect and better fire performance, the concretefilled steel tube(CFST) arch bridge is one of the bridge structures that have broad prospectsfor development. Along with the appliance of concrete-filled steel tube technology in bridgeengineering,many problems are exposed and separation is the one of the most commonproblems. But this kind of bridges has a short development period in China, and many aspectsare studied insufficiently. The situation will bring the adverse effect to the concrete filled steeltube string arch bridge’s development.The dissertation developed a series of case study and theoretical analysis to theseparation effects to mechanical behavior on CFST arch bridge.The paper study a large spanCFST arch bridge with the universal FEM software ANSYS. Two3-D finite element modelsare built according to complete debonding and complete bonding. The static force, stability,dynamic characteristics of the bridge in the state of complete separation and complete bondare analyzed in the paper.Then the structural displacement and internal force under self loudaction, instable modality and stable coefficient of different state, the natural vibrationfrequencies and modes are discussed. The results indicated that separation reduce structuralstability,stiffness and natural vibration frequency. Besides, the analysis of structure parameters,such as steel ratio, leaning angle, separation ratio and separation location, influence onstructure stability and structure stiffness, then some conclusions are drawn. The result isusable for the reinforcement design of this same kind of bridge.