HR: 0830h
AN: S51E-0094    [PDF]
TI: Estimation of Site Response in Time Domain Using Meyer-Yamada Wavelet Analysis
AU: Birgoren, G
EM: gulum@egmdpri01.dpri.kyoto-u.ac.jp
AF: DPRI,Kyoto Un., Kyoto University,DPRI,Section of Strong Motion Seismology, Uji, 611-0011 Japan
AU: * Irikura, K
EM: irikura@egmdpri01.dpri.kyoto-u.ac.jp
AF: DPRI,Kyoto Un., Kyoto University,DPRI,Section of Strong Motion Seismology, Uji, 611-0011 Japan
AB: In most applications of Stochastic Green's Function Simulation, amplitude characteristics of seismic responses at target sites are taken into consideration but phase information of them is often disregarded or just assumed to be random. However, when seismic waves from the source pass through different geological strata, they take multiple paths and as result, the arrival times of different seismic phases to the receiver vary. Especially in the basin structures, seismic waves trapped in unconsolidated deposits or secondarily induced at the basin edges elongate the duration of ground motion. In the present study, a simple empirical method using the Meyer-Yamada wavelet procedure is proposed for the phase dependent site response estimation in time domain. The method reveals the amplitude and phase effects of extended duration of ground motion on site response utilizing the wavelet transform. Because the wavelet transform yields a localization of a signal in both frequency and time domains, the phase information of the signal stays intact. Application of this method has been performed using the aftershock records of the 1999 Duzce, Turkey Earthquake. First, a spectral calculation method of site response has been introduced and amplitude spectra of the absolute site responses were estimated at each station. Second, the site responses in time domain were calculated by the wavelet method and the results for basin stations and hard soil stations were compared. The good agreement between the amplitude spectra calculated with the wavelet and those of the spectral calculation method supports the validity of the proposed method.
DE: 7212 Earthquake ground motions and engineering
DE: 7223 Seismic hazard assessment and prediction
SC: Seismology [S]
MN: 2003 Fall Meeting