Dynamic performance evaluation of a 492 m super high-rise building with active tuned mass dampers during four consecutive landfall typhoons within a month

Abstract

Field measurement is the most reliable and intuitive method to assess the wind effects of super high-rise buildings. However, due to the different inherent characteristics of each typhoon, the observations may be different or even contradictory. Therefore, there is a need to conduct further analysis on the wind effects during typhoons to reveal more general results. In this study, wind-induced acceleration responses collected by the structural health monitoring system installed atop the Shanghai World Financial Center (SWFC) during the landfall of four consecutive typhoons (Ampil, Jongdari, Yagi and Rumbia) within a month are systematically investigated. The first five-order modal directions are determined based on the spectral method. The envelope random decrement technique is adopted to identify the natural frequencies and damping ratios, and the amplitude dependencies and time-varying characteristics of the structural dynamic properties are also analyzed. Furthermore, the control performance of active tuned mass damper (ATMD) system during typhoons is discussed. Finally, the serviceability of the skyscraper during typhoons is assessed, and the global damage evaluation is performed. The results show that the natural frequencies decrease with increasing amplitude and present V-shaped variation trends with time. The damping ratios almost increase with increasing amplitudes but do not show any noticeable variation trend with time. The time-varying environmental conditions may have considerable effects on the modal parameters, and those effects may be superimposed in a short time. The ATMD system can effectively mitigate wind-induced vibrations. The occupant comfort is satisfactory, and no evident structural damage is detected during typhoons.