Investigation of dynamic properties of tall buildings under super typhoon Mangkhut via Bayesian method

Abstract

Investigations into the variation law of modal parameters of tall buildings under typhoon events via field measurements have been performed extensively in recent decades. In this study, the dynamic properties of tall buildings under super typhoon Mangkhut are investigated via Bayesian operational modal analysis (BAYOMA), which provides the most probable value and identification uncertainty. First, numerical examples are presented to illustrate the excellent performance of BAYOMA in identifying time-varying structural dynamic properties under colored noise excitations. Subsequently, BAYOMA is performed to identify the modal parameters of two tall buildings with different configurations, namely, the Zhuoyue Century Center (280 m) and Guangzhou West Tower (432 m), using measured acceleration responses atop the buildings under significant structural vibration amplitudes (maximum accelerations of approximately 20 mill-g) during Mangkhut. Variations in the natural frequencies and damping ratios with respect to time and amplitude are investigated and discussed. The identified natural frequencies vary significantly with time. An investigation into the identified natural frequencies vs. the modal root-mean-square shows a negative correlation. Meanwhile, the damping ratios show a large dispersion but remain in the same order of magnitude and do not exhibit significant time-varying and amplitude-dependent features. The aim of this study is to provide further understanding into the in-situ dynamic properties of tall buildings and provide an important reference for wind-resistant design and wind-induced vibration control under severe typhoon conditions.