EVALUATION OF SITE EFFECTS ON ENERGY SPECTRA OF GROUND MOTIONS OBSERVED DURING THE 1987 CHIBA-KEN-TOHO-OKI EARTHQUAKE

Abstract

Site effects on energy spectra of ground motions observed at 173 sites during the 1987 Chiba-ken-toho-oki earthquake (M=6.7) were evaluated. The results indicate that 1) the site effects on the energy spectra are almost same as those on the response spectra, and 2) the energy spectra have the similar spectral shape to the velocity response spectra, but the ratio of the former to the latter depends on the duration of ground motion.