ABSTRACT
The wind records during extreme events, for both tropical and extratropical cases, in recent field measurements are observed to inherently contain strong nonstationary features, which indicate a deviation from the traditional stationary assumption. In this study, Typhoon Fung-Wong recorded by the SHMS at Sutong Bridge site in 2008 is taken for the investigation of stationary and nonstationary wind characteristics. The stationarity of the wind speed is first evaluated with the commonly used run test method. And the relationship between stationary portion and the time interval is presented. For nonstationary cases, the wavelet decomposition is an efficient method to extract the time-varying mean. But there is no definite criterion to determine the number of the decomposed levels. Accordingly, a method combining the run test method and the wavelet decomposition is proposed to automatically extract the time-varying mean of a nonstationary wind record. Then, the wind data are analyzed based on both the traditional stationary and the nonstationary wind speed models. The obtained wind characteristics such as the mean wind speed, turbulence intensity, gust factor, turbulence integral scale and power spectral density are compared accordingly. Also, some of the commonly used empirical models, which have been adopted in specifications, related to the wind characteristics are verified in both stationary and nonstationary cases. The results of this study can provide references for the nonstationary analysis of wind characteristics and enrich the nonstationary database used for design in the future. Power spectral density analysis on the turbulence based on stationary and nonstationary models https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315207681/cd556cd4-4dcf-4efe-8e29-56fc67b8bfbd/content/fig92_1.tif"/>
