Aerodynamic Parameter Research And Wind-Induced Response Analysis For Railway Cable-Stayed Bridge

The aerodynamic parameter of a girder is an important parameter, standing for the corresponding relation between bridge deck style and wind load, which is the basement of wind-induced response analysis for bridge. It is of great importance to identify the aerodynamic parameter of bridge deck and study on the influencing factors. The aerodynamic parameters of a steel truss girder used in a long-span cable-stayed bridge were measured in wind tunnel. By means of wind tunnel test and theoretical analysis, the dynamic response of the cable-stayed bridge has been analyzed. Following five aspects are included in this thesis:(1) The type of wind loads on bridges was introduced. The measure methods of static wind loads and buffet forces on sectional models of bridges were introduced.(2) The three-component force coefficients of the girder were measured through three-component balance in the uniform flow fields of wind tunnel. In the course of the tests, the influence of train was also considered.(3) The aerodynamic admittance of the girder were identified based on self-spectrum method through high-frequency-force-balance in the nonuniform flow fields of wind tunnel. The influences of wind speed, attack angle and layout of train on aerodynamic admittance of the girder were studied. By numerical simulation, the formulas of aerodynamic admittance functions of truss section, which could be used in calculating three-components of aerodynamic load, were proposed respectively.(4) The aerostatic response and buffeting response of the cable-stayed bridge based on the testing aerodynamic parameters were analyzed. Comparing the calculated results with the results measured by the full aeroelastic bridge model wind tunnel test, the validity of the testing method for aerodynamic parameter was proved.