Evaluation of modal properties of high-rise buildings under severe typhoon conditions using correlation function-based modal identification methods

The correlation function-based methods have been widely in the operational modal analysis of engineering structures. However, the understanding of the advantages and disadvantages of these methods for modal estimation remains limited, which may result in inappropriate settings for key parameters adopted in these methods, thereby introducing errors in modal identification. Besides, the non-stationary features of the responses of high-rise buildings under severe wind conditions are a critical factor affecting the accuracy of modal estimates. To address these issues, the performances of several widely used correlation function-based methods are investigated via numerical simulation study of a frame structure. Then, two time-frequency domain methods with obvious advantages are selected and employed to analyze the dynamic responses of a 600 m high supertall building to determine the key parameters adopted in these techniques, and further evaluate the dynamic properties of the skyscraper during two super typhoons. Based on the reliable modal estimates, the time-varying features and amplitude dependency of modal properties as well as the natural frequency-dependent feature in damping ratios are presented and discussed. This paper aims to present effective tools for modal estimation through assessing the performances of the correlation function-based methods and determining the key settings in these methods as well as reveal the dynamic characteristics of high-rise buildings under severe typhoon conditions.