The effect of amplitude-dependent damping on wind-induced vibrations of a super tall building

Abstract

Full-scale measurements of wind effects on a 70 storey tall building have been conducted. The tall building that has a height of 367 m is the second tallest structure in Hong Kong. The amplitude-dependent characteristics of damping have been obtained by using the random decrement technique from the field measurements of acceleration responses. The objective of this study is to present detailed investigations into the effects of amplitude-dependent damping on the wind-induced responses of the super tall building based on the measured non-linear damping and wind action characteristics. An efficient and less time consuming digital simulation technique is developed to generate time series of turbulent wind loads acting on the tall building based on the measured wind speed records. The predicted dynamic responses of the building using the actual amplitude-dependent damping characteristics are compared with those computed by using constant damping parameters assumed by the structural designers or estimated from the field measurements in order to evaluate the adequacy of current design practices and to apply that knowledge to structural design of tall buildings. It is observed from this study that the effect of amplitude-dependent damping on the dynamic responses of such a super tall building is significant and knowledge of actual damping characteristics is very important in the accurate prediction of wind-induced vibrations of a tall building.