Field Measurement Of The Natural Wind Characteristics In Coastal Region And Research Of Buffeting Response Of Long Span Bridge

Field measurement of wind characteristics is one of the basic research topics in bridge wind engineering. The wind characteristics results based on field measurement can provide a reference for the modification of wind tunnel simulation technology of natural wind, the field measurement of buffeting response can be used as a case study which provides the validation and calibration for buffeting analysis theory and wind tunnel test technology. Based on the field measurement of typhoon and strong monsoons, this paper presents the field measurement results of natural wind characteristics in coastal region of China, including mean wind speed, mean wind direction, mean wind attack angle, turbulent intensities, gust factors, turbulence integral length scales, power spectrum of wind speed and spatial correlation of gusty wind, the profiles of mean wind speed and turbulent intensity, etc.. The correlation among wind characteristics is analyzed in detail. Aerodynamic load on girder, the buffeting response under skew wind and so on are elaborated using the combined method of field measurement, wind-tunnel test and theoretical analysis. These results can provide detailed wind characteristics of coastal areas of China, which can be taken as a reference for the design and construction of other similar long-span bridges. In summary, following five aspects have been covered in context:1. The field measurement system of wind characteristics, the observation station, data reduction and the analysis of wind parameters about the wind characteristic parameters are introduced.2. The field data about strong wind and strong monsoon are obtained through long-term and continuous field measurement in coastal region. The wind characteristics including mean wind speed, mean wind direction, mean wind attack angle, the profiles of mean wind speed and mean turbulence intensity, turbulent intensity, gust factors, turbulence integral length scales, spectrum and spatial correlation of gusty wind and so on are obtained based on the results of field data. The relationship among of the wind characteristics is analyzed in detail.3. Based on field measurement of buffeting response and full aeroelastic bridge model wind tunnel test, the buffeting response of long-span bridge is investigated. The influence of skew wind to buffeting response is analysized.4. The characteristic of aerodynamic force is studied based on full scale and large-scale section model wind tunnel test by using the self-developed200channel synchronization pulse pressure measurement system. And the coefficient of three-components of aerodynamics force and aerodynamic admittance function under the skew wind are identified.5. Based on wind characteristics of field measurement, three-components of aerodynamic force and aerodynamic admittance function under skew wind, modified flutter derivatives, a buffeting analysis method based on pseudo-excitation method for long span bridge is developed. The results show that the analysis method is valid and high accuracy.