Field Measurement Of Typhoon Wind Characteristics In Coastal Areas

At present,wind speed is defined as a stationary stochastic process in the wind resistance design codes of most countries in the world.However,the analysis results of a large number of wind speed measured data show that the number of non-stationary samples in the data increase significantly when the surrounding environment of the measured point is very complicated or strong winds such as typhoons and hurricanes pass.Therefore,the wind-resistant design based on the smooth wind speed model is inevitably not in line with actual needs.In addition,the wind load acting on the building is determined by the wind field characteristic parameters,and the wind field characteristics are greatly affected by the wind speed properties.Therefore,it is necessary to study the wind field characteristics under the non-stationary wind speed model.In this paper,using the typhoon measured data obtained from the 356 m meteorological gradient observation tower of Shenzhen and the CITIC Plaza wind effect monitoring platform in Guangzhou,the atmospheric boundary layer wind profile and typhoon turbulence characteristics of the coastal area are analyzed based on the steady wind speed model,and the atmosphere boundary layer state is determined according to the Z/L judgment method.The aerodynamic parameters near the meteorological gradient tower around Shenzhen are studied.The ground roughness coefficient of the area is calculated according to the measured wind profile,and the applicable heights of logarithm law,exponential law and D-H model are further analyzed.Secondly,the turbulence characteristics of different inflow directions under typhoon conditions are studied,and the relationship between typhoon turbulence characteristics and average wind speed and altitude is obtained.The characterization of the Von Karman empirical spectrum on the power spectrum of pulsating wind speeds under different wind directions is evaluated.Then,based on the non-stationary wind speed model,the non-stationary component of the measured typhoon wind speed is detected by the round test method,and the time-varying average wind in the typhoon wind speed data is extracted by wavelet transform,and the accuracy is verified by round test method.The probability density distribution of the pulsating wind speed is obtained,and its random distribution characteristics are revealed.The typhoon turbulence characteristics of different winds directions under non-stationary wind speed model are analyzed.Based on this,the relationship between typhoon turbulence characteristics and average wind speed and height under non-stationary wind speed model is discussed.Finally,the pulsating wind speed power spectrum of different wind directions under non-stationary wind speed model is evaluated,and its fitting result with Von Karman experience spectrum is investigated.In this paper,the differences between the theoretical assumptions and the calculation formulas of the stationary and non-stationary wind speed models are discussed.The constant mean wind and the non-stationary wind speed model are obtained by the steady wind speed model to obtain the time-varying average wind.The advantages and disadvantages to describe the variation trend of the measured typhoon wind speed of the two models are compared.The difference between the probability density distribution of pulsating wind speed under the stationary and non-stationary wind speed models is studied.The turbulence characteristics of different wind directions under two wind speed models are compared and analyzed.