Abstract:
Combined with the long-term measured data of the 3D ultrasonic anemometer at the bridge deck of a long-span cable-stayed bridge in the upper canyon area of the Yellow River, the wind field characteristics of the bridge site area were statistically analyzed, and the wind speed, wind direction, wind attack angle, turbulence intensity, gust factor, turbulence integral scale and power spectral density function of the bridge site area were analyzed based on the samples with an average wind speed of more than 5.5 m/s. The results show that the canyon topography has a locking effect on the wind direction at the bridge site. The wind angle of attack is mainly negative, and there is a significant correlation between wind speed, wind direction and wind angle of attack. There is a significant positive correlation between the turbulence intensity, gust factor and turbulence intensity of each component. The turbulence integral scale has a significant negative correlation with the turbulence intensity and gust factor, respectively, and with the increase of turbulence intensity and gust factor, the turbulence integral scale decreases sharply at first and then tends to stabilize. In this paper, the fitting formula for the correlation between turbulence integral scale and turbulence intensity given in previous studies is modified according to the measured data, and the fitting formula for the correlation between turbulence integral scale and gust factor is given. The fitting effect of the measured power spectrum is poor with the theoretical spectrum of the specification recommendation, and the wind spectrum model suitable for the local area is obtained according to the fitting of the measured data, and the longitudinal and transverse results fit well with von Karman spectrum, and the vertical fitting with Panofsky spectrum is better. The research results can provide a practical reference for the wind-resistant design of engineering structures in the upper reaches of the Yellow River.