Long-term monitoring of wind characteristics at Sutong Bridge site

The Sutong Bridge is vulnerable to Pacific typhoons since it is located in the east coastal area of China. Therefore, the dynamic action on the bridge induced by the turbulence wind needs special consideration. In order to obtain the turbulent characteristics at the bridge site, 3D ultrasonic anemometers are included in the Structural Health Monitoring System (SHMS) to collect wind data. In this paper, the recorded real-time wind data are analyzed in detail to generate the wind-rose diagram, mean wind speed and direction, turbulence intensity, turbulence integral scale, and power spectral density. Comparative analyses are then conducted among the inhomogeneous wind characteristics of three strong wind events, including the Northern wind, Typhoon Kalmaegi and Typhoon Fung-Wong. In addition, calculated wind characteristic values and those recommended in the current design specification are compared. Results show that turbulence intensities decrease as the mean wind speed increases, except in the area with the superposition of general winds and typhoons. Meanwhile, turbulence intensities of the typhoons are different from the values recommended by the current design specification. In addition, the measured power spectra in the along-wind direction match relatively well with the Kaimal spectra, whereas in the vertical direction, apparent deviations can be witnessed. The conclusions can be used to determine the wind parameters of the east coastal area of China, and as references for wind-resistant evaluation of bridges in the area.