Analysis Of The Effect Of Wind Characteristics On Buffeting Of Long-Span Bridges

Wind resistance of long-span bridge has become a hot spot in civil engineering. Along with increase of span of bridge, wind resistance problem of long-span bridge is more highlighted. Many scholars have carried out research about mechanism of wind induced vibrations and how to control them from different angles. Thus, a series of achievement have been created. This thesis focuses on influence of turbulent wind characteristics to buffeting responses of long-span bridge, the main contains are as follow:Two dimension buffeting theory is used to analyze influence of turbulence integral scale to buffeting responses. Hangzhou Bay Bridge and Jiangyin Yangtze River Bridge are selected as research object to calculate buffeting responses under different turbulence integral scales from 5m to 100m. It turns out that buffeting responses does not change with turbulence integral scale linearly. In the first stage, buffeting responses increase with the growth of turbulence integral scale. But when turbulence integral scale reaches one value, buffeting responses become the highest value. After that, buffeting responses decline with the growth of turbulence integral scale. Secondly, turbulence integral scale corresponding to peak value of buffeting responses rises with growth of wind speed.Time domain analysis method is used to analyze influence of turbulence intensity to buffeting responses. Binzhou Yellow River Bridge is selected as research object. Turbulence wind speed time series simulation and numerical identification of aerostatic force by CFD method are conducted at first. Then the analyses are carried out in ANSYS. It turned out that it is different that the influence of turbulence intensity to buffeting responses in different direction. Turbulence intensity has so little influence to buffeting displacements of bridge span direction and vertical direction that it can be ignored. Turbulence intensity has also little influence to the buffeting velocity and buffeting acceleration of bridge span direction. However, its influence to vertical buffeting velocity and acceleration is obvious, vertical buffeting velocity and acceleration increase with rise of turbulence intensity. Turbulence intensity has little influence to the maximum of vertical buffeting displacements, velocity and acceleration, and it has no influence to those value of bridge span direction. The maximum of vertical buffeting responses are larger than the maximum of buffeting responses of bridge span direction. The correlation of buffeting responses of symmetrical nodes in bridge span direction is larger than the correlation of vertical buffeting responses of symmetrical nodes.