Generation method of broadband statistical green's functions of horizontal and vertical ground motions

Abstract

A generation method of broadband statistical Green's functions of horizontal and vertical ground motions is proposed. The method includs following new contents. 1. Near-filed and intermediate terms as well as the far filed term of the source spectra are considered. 2. The ratio of corner frequency of P-wave to that of S-wave is assumed to be the ratio of P-wave velocity to S-wave velocity. 3. Scattering effects are considered into the path spectra in the high-frequency range. 4. Site effects for vertical motions are represented by 1-D theoretical amplification factors assuming obliquely incidence P- and S-waves in the low-frequency range and vertical incidence P-wave in the high-frequency range. The method is verified by comparison between the generated statistical Green's functions and near-field records during the 1998 Miyagiken-Nanbu earthquake with Mj=5.2.