ANALYSIS OF VERTICAL GROUND MOTIONS AND PHASE MOTIONS OF NEAR FAULT RECORDS IN JAPAN AND ITS APPLICATION TO SIMULATION OF VERTICAL GROUND MOTIONS

Abstract

 The vertical component of the ground motion recorded near the source in inland earthquakes occurred in Japan Island and the characteristics of the phase ground motion are studied. Also the vertical component of the ground motion synthesized using a thrust source model is studied. The curves for the Fourier spectral amplitude ratios of vertical to horizontal components are analyzed and summarized in terms of the mean and standard deviation of them for three surface soil conditions. Artificial vertical ground motions simulated using the proposed Fourier spectral amplitude ratios and the phase motions are compared with the records, in order to demonstrate an engineering capability of the proposed simulation method of vertical ground motions.