掲載雑誌（和）： 日本地震工学シンポジウム講演集 Vol： 6巻 年： 1982年 頁： 65-72頁 著者（和）： - タイトル（和）： - 抄録（和）：
- キーワード（和）： - 掲載雑誌（英）： PROCEEDINGS OF JAPAN EARTHQUAKE ENGINEERING SYMPOSIUM 著者（英）： Shigeru KASUGA, Kojiro IRIKURA タイトル（英）： LATERAL VARIATIONS OF GROUND MOTIONS ON SURFACE LAYERS WITH A HORIZONTAL DISCONTINUITY 抄録（英）：
Earthquake ground motions have been observed at the area, located at the eastern edge of the Kyoto Basin, where the underground structures contain a horizontally irregular interface with an abrupt change of sedimentary layer thickness. Amplification effects due to underground structures are estimated from spectral ratios of S wave ground motions at the soft ground to those at the rock outcrop. Predominant frequencies of the amplifications at the several points near and across the horizontal discontinuity are similar to each other, however, amplification factors at the predominant frequencies increase remarkably with the steep increase of the thickness of soft surface layers. Ground motions at the site lying on the thick soft layers tend to have significantly longer duration times than those on the thin ones. At the former sites, remarkable phases longer than main parts of S waves appear subsequently to S phases. On the other hand, at the latter sites, those vanish shortly after S phases. These observed results show that the local geological conditions cause abrupt lateral-changes of amplitudes and duration times of the ground motions. The observed ground motions are compared with the theoretical ones calculated by the discrete wave number method and the singular integral equation method. キーワード（英）： - 記事区分： - 区分 　　　委員会論文集