Shrinkage And Creep Effects Analysis Of Super Wide Concrete Self-anchored Suspension Bridge

The self-anchored suspension bridge is a highly competitive bridge type in urban landscape bridges,with its beautiful appearance and strong adaptability to geological conditions.As the amount of urban traffic increases,the width of the bridge also increases,and the super wide concrete self-anchored suspension bridge is applied.The shrinkage and creep of concrete have a great effect on the mechanical properties and long-term deformation of bridge structures.With the increase of the width of concrete girder,the shrinkage and creep effects of super wide concrete self-anchored suspension bridge become more complex.In order to ensure reasonable alignment and safe operation of the bridge structure,this dissertation attempts to analyze the shrinkage and creep effects of super wide concrete self-anchored suspension bridge with Hunan Road Bridge as the engineering background.The main contents are as follows:(1)Research on numerical analysis model of the super wide concrete self-anchored suspension bridge.Based on the finite displacement theory,three three-dimensional spatial models are established respectively,namely double-girder model,spatial grillage model and solid finite element model.The spatial grillage model can simulate the spatial effect of the stiffness distribution of the super wide girder by mutual verification,which is suitable for the analysis of shrinkage and creep effects of the super wide concrete self-anchored suspension bridge with accuracy and efficiency.(2)Research on effects of concrete shrinkage and creep on super wide self-anchored suspension bridge.Based on the established finite element analysis models,both shrinkage and creep effects and geometric nonlinear effects are considered while simulating the actual construction and operation stage of the bridge.The effects of concrete shrinkage and creep on the structure alignment and the internal force of main girder,main tower,main cable and hanger are analyzed.The change of support reaction and the loss of prestress caused by shrinkage and creep effects of super wide self-anchored suspension bridge are studied.The relative differences between the results calculated by different codes are also discussed.(3)Research on measurement verification of super wide concrete self-anchored suspension bridge.According to the characteristics of Hunan Road Bridge,the operation monitoring scheme is designed and the field monitoring is carried out.Through the monitoring of the structure alignment and internal force,it is considered that the effects of concrete shrinkage and creep play a dominant role in the stress and deformation of the structure.The numerical analysis results are in good agreement with the operation monitoring data,thus verifying the reliability of the finite element analysis.(4)Research on the concrete shrinkage and creep analysis method and program development.According to the calculation theory of shrinkage and creep and geometric nonlinear finite element method,the age-adjusted effective modulus method and finite element method are combined to form a more realistic creep analysis method(AEMM-FEM),which the effect of geometric nonlinearity is taken into account.Based on this method,a program for calculation and analysis of concrete shrinkage and creep effects is developed,and the program is applied to the shrinkage and creep effects analysis of Hunan Road Bridge.The algorithm and program are reliable,which is consistent with the calculation results of finite element software.In the geometrical nonlinearity methods,the C.R.formula method is more suitable for the analysis of concrete shrinkage and creep effects.