Research On Vibration Of The Bridge Pylon During Construction

As the main load taken structure of a bridge, the bridge pylon becomes higher by the span. Since the span of modern bridge becomes wider and wider, the bridge pylon will be higher and higher. A bridge pylon is a kind of high-rise structure, and wind load is its main sidewise load. A naked pylon is not supported by cables in construction state. It's one of key states in wind-resistent design. So it's very significant to research buffeting of a bridge pylon in construction state.The dissertation introduces theoretical knowledge of buffeting at first, clarifies two methods of buffeting analysis: time-domain method and frequency-domain method, introduces simulation of the time series of turbulent wind velocity. The aeroelastic model tunnel test is a very important means to research buffeting of a bridge pylon. Its theoretical base is the analog principle, with two premises: correct simulation of the structure and correct simulation of wind environment. Design and production of aeroelastic models and simulation of wind field are specially introduced in the paper.The dissertation takes an example with the pylon of the Edong Yangtze River Highway Bridge, from determining ratio of wind velocity and deciding wind velocity in test, to design and production of the model, simulation of wind field, setting survey points, designing cases in the test, measuring the response, till dealing with test data, detailedly clarifies the aeroelastic model tunnel test. The test researches the relation between buffeting response of the bridge pylon and wind velocity of different wind yaw angles in three main construction states, obtains some statistical results, such as: mean and RMS of displacement. For the state that the bridge pylon is completed, mean wind calculation and buffeting response analysis in time domain is conducted. Some useful conclusions have been obtained by comparing the test result with the analysis result.