Research About The Composite Working Effect Between Steel Tube And Confined Concrete Of Concrete-filled Steel Tube Arch Bridge

Though concrete-filled steel tube arch bridges have been built many at present,and the research about its stability of construction,control of construction and the force analysis are also studied for many times, there are still some vacancy in the study and cognition of steel tube and the concrete's composite effect about cut and slippage and bonding etc.So this paper take study on this problem of interfacial contact between steel tube and confined concrete,aiming at making people have further cognition of the effect of the composite effect and working mechanism of concretefilled steel tube arch bridge.Thus design and construction practice can be guided better.The research work and main achievement includes:(1)The constitutive relationship between steel tube and confined concrete are introduced,because contact problem is the set of material nonlinearity and states nonlinearity,material's constitutive has important influence on problems'convergence and ultimate result.Meanhile the method of limit equilibrium is used to analyze the arch rib forced state of pre and post sliding, shearing and sliding's ansys solid model is introduced and the model is used to analyze signle limb arch rib between two adjacent suspender,the conclusion is got that friction stress,sliding distance and compressive stress's time history response curve by applying monotonic enhancive load.The changing laws and the main stages contact states are got when the load is applied from initial time to ultimat bearing capacity.(2)Part of scattered bond theory is classified and summarized .The model is built to study the effect of internal force distribution between steel tube and confined concrete composite section when bond exist.The working mechanism of steel tube confined concrete's bonding and sliding and the main factors which influence the bonding performance of it are studied and summarized.The phenomenon of back of arch disengaging caused by concrete gravity,drying shrinkage,force and crack which has universal existence in projects is modeled and analyzed.The effect of force and deformation is got about steel tube and confined concrete caused by them.(3) The YinChuan's YueHai bridge-halfthrough concretefilled steel tube arch bridge is taked for example,bonding behavior of concrete-filled steel tube arch bridge in construction processe is studied, the axial force and bending moment effect in construction process caused by bonding and steel tube and confined concrete's contact states is mainly included.Measured stress data is analyzed,the bonding and sliding states of steel tube and confined conrete can be obtained from steel and concrete's stress measured curve's developing tendency,then both completely separated model and fully bonding matrixing element.model are built.the two kind of models above are compared to obtain that the mechanical effect from bonding to arch rib is mainly based on bending moment. these thory data is compared with measuring data,the conclusion is got that in the construction's terminal phase,both of the two materials'bonding degree are not strong,more close to separated states.