Evaluation of wind loads on super-tall buildings from field-measured wind-induced acceleration response

With the nonstationary wind-induced acceleration data from full-scale measurements, an approach for estimation of the wind-induced overturning bending moments for super-tall buildings was proposed in this paper. The empirical mode decomposition was employed to decompose the measured acceleration data into a set of intrinsic mode functions and a residual component. To remove the baseline offset, the residual component and the intrinsic mode function components with long-period were eliminated before their integrations into velocity and displacement components. Then, the intrinsic mode function components, which have the same dominant periods as the natural periods of the studied tall buildings, were extracted from the original signals, and the natural frequency and damping ratio for the first vibration mode of the building were identified. Finally, the wind-induced overturning bending moments of the building were obtained from the generalized wind loads for the first vibration mode, which could be obtained from the time history analysis of dynamic equation. The Hilbert spectrum of wind-induced overturning bending moments was utilized to observe its characteristics in both time and frequency domains, and the Strouhal number was thus identified. The proposed scheme and some selected results may be helpful for further understanding of wind effects on super-tall buildings. Copyright © 2012 John Wiley & Sons, Ltd.