Numerical Simulation Of Turbulent Wind Field And Analysis On Wind-induced Bridge Vibration

ABSTRACT:Railway bridges will suffer large excitations when they locate in a strong wind area. Therefore it is an important prerequisition to analyze these bridges for ensuring the structure stability and train running safety. Taking the newly built Lanzhou-Xinjiang railway line as the engineering background, the turbulent wind field of the bridge in the windy zone is simulated. Then the dynamic responses of the bridge due to wind actions are calculated. The main contents and conclusions of this dissertation are as follows:(1) Wind induced catastrophe of bridge structures is reviewed at home and abroad first. The vibration theory of bridges subjected to wind actions is clarified and the importance of the related research is introduced. Herein, wind damages occurring in Lanzhou-Xinjiang railway line are especially put emphasis on.(2) Based on the random process theory, two methods of the numerical simulation of turbulent wind field are introduced, including the linear filter method and the spectral representation method.(3) Based on the design of a32m simply-supported box girder bridge and a16m simply-supported U-girder bridge in the windy zone of the railway line, the two bridges are modeled with the help of the finite element method. Their fundamental vibration characteristics are analyzed.(4) The turbulent wind fields of the bridges are simulated by the spectral representation method. The static and buffeting wind loads of the bridge are simulated according to the tri-component force coefficient results from the wind tunnel tests.(5) The dynamic responses of two railway bridges subjected to wind loads are computed under multi-cases. Some useful conclusions can be obtained.