Modal parameter identification of Tsing Ma Bridge during typhoon victor: EMD-HT approach

Modal parameters of the Tsing Ma Bridge are identified from the bridge responses measured during Typhoon Victor using the newly-emerged empirical mode decomposition (EMD) method in conjunction with the Hilbert-transform (HT) technique. Natural frequencies and modal damping ratios identified by the EMD-HT approach are first compared with those obtained by the traditional fast Fourier transform (FFT) method. The EMD-HT approach is then used to examine bridge modal parameters identified from different sensors at different locations. Finally, the EMD-HT approach is used to investigate variations of natural frequency and total modal damping ratio of the Bridge with vibration amplitude and mean wind speed. It is demonstrated that the EMD-HT approach is applicable to modal parameter identification of large civil structures using field measurement data, and the EMDHT approach is better than the FFT method.