A FIELD MEASUREMENT SYSTEM FOR WIND ENGINEERING AND ANALYSIS OF TYPHOON CHARACTERISTICS BY ULTRASONIC ANEMOMETERS

摘要

A low-rise building and a tower were constructed near Shanghai Pudong International Airport by East China Sea to investigate characteristics of wind field and wind pressure on the surface of the roof. This paper firstly introduces the overview of the field measurement system and then presents the field measurement results of near-ground wind characteristics over a typical flat area near the Yangtze River estuary during typhoon HAIKUI. Variations of the wind characteristic parameters, such as mean wind speed, longitudinal turbulence intensity, gust factor and turbulence integral scale, along the height are analysed. It is found that the neutral atmospheric stratification (vertical bar z/L vertical bar = 0.1) occurred in the periods corresponding to the relatively high mean wind speed, and z/L has greater dispersion when the wind speed is relatively low. The dispersion of friction velocity is large when wind speed is small, and its variation with the mean wind speed is not obvious, but when the mean wind speed is larger, the friction velocity increases significantly with the mean wind speed. The measured mean wind speed profile is in good agreement with power and logarithmic law. Besides, the profiles of turbulence intensity, gust factor and turbulence integral scale factor are presented and empirical expressions are given by fitting the profile curve, which is useful for wind-resistant design of engineering structures in the future.