Assessment of the validity of the one-dimensional approximation in the velocity Structure Modeling Based on the Spatial Correlation of Seismic Motions

PreviousNext No AccessProceedings of the 14th SEGJ International Symposium, Online, 18–21 October 2021Assessment of the validity of the one-dimensional approximation in the velocity Structure Modeling Based on the Spatial Correlation of Seismic MotionsAuthors: Daiki ToriiHiroaki SatoShoma YamamotoAtsushi OkazakiDaiki ToriiCentral Research Institute of Electric Power IndustrySearch for more papers by this author, Hiroaki SatoCentral Research Institute of Electric Power IndustrySearch for more papers by this author, Shoma YamamotoThe Kansai Electric Power Co., Inc.Search for more papers by this author, and Atsushi OkazakiThe Kansai Electric Power Co., Inc.Search for more papers by this authorhttps://doi.org/10.1190/segj2021-022.1 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract The velocity structure models used for earthquake ground motion evaluation at critical facility sites are often constructed using average 1D models based on geophysical exploration such as PS logging, seismic reflection survey, and microtremor array survey. Therefore, it is important to check the validity of the one-dimensional approximation in modeling. In this respect, it is often applied to verify the stability of the amplification characteristics using earthquake records with different directions. However, this method is not applicable when there is a bias in the epicentral distribution around the site. In this study, we conducted a dense seismic observation at the target site. We then tried a new approach to evaluate the validity of the one-dimensional approximation in modeling at the site based on the spatial correlation of the cross-correlation coefficient between observation stations. As a result, the characteristic of the spatial correlation was getting smaller with the distance between stations and then asymptotically approached a constant value. Furthermore, this distance-dependent feature was found to have a shorter distance and a smaller constant value with a higher frequency. Finally, we evaluated the validity of the one-dimensional approximation based on the similarity of the spatial correlations in each area, which are mathematically modeled by the exponential-type autocorrelation function. Keywords: spatial correlations, cross-correlation, dense seismic observation, one-dimensional approximationPermalink: https://doi.org/10.1190/segj2021-022.1FiguresReferencesRelatedDetails Proceedings of the 14th SEGJ International Symposium, Online, 18–21 October 2021ISSN (online):2159-6832Copyright: 2021 Pages: 349 publication data© 2021 Published in electronic format with permission by the Society of Exploration Geophysicists of JapanPublisher:Society of Exploration GeophysicistsSociety of Exploration Geophysicists of Japan HistoryPublished Online: 29 Nov 2021 CITATION INFORMATION Daiki Torii, Hiroaki Sato, Shoma Yamamoto, and Atsushi Okazaki, (2021), "Assessment of the validity of the one-dimensional approximation in the velocity Structure Modeling Based on the Spatial Correlation of Seismic Motions," SEG Global Meeting Abstracts : 79-82. https://doi.org/10.1190/segj2021-022.1 Plain-Language Summary Keywordsspatial correlationscross-correlationdense seismic observationone-dimensional approximationPDF DownloadLoading ...