Estimation of Vs30 and site classification of Bhaktapur district, Nepal using microtremor array measurement
Abstract The severe damage observed in the Kathmandu Basin, Nepal, during past earthquakes necessitates a thorough study of the seismic behavior of the basin sediments. As the shear-wave velocity is directly related to the elastic shear modulus of the material, it is essential to determine it to inc...
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| Language: | English |
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SpringerOpen
2024-10-01
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| Series: | Earth, Planets and Space |
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| Online Access: | https://doi.org/10.1186/s40623-024-02077-6 |
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| author | Roshan Prajapati Salim Dhonju Subeg Man Bijukchhen Michiko Shigefuji Nobuo Takai |
| author_facet | Roshan Prajapati Salim Dhonju Subeg Man Bijukchhen Michiko Shigefuji Nobuo Takai |
| author_sort | Roshan Prajapati |
| collection | DOAJ |
| description | Abstract The severe damage observed in the Kathmandu Basin, Nepal, during past earthquakes necessitates a thorough study of the seismic behavior of the basin sediments. As the shear-wave velocity is directly related to the elastic shear modulus of the material, it is essential to determine it to incorporate the behavior of the soil in the design of the structure. Hence, we determined average shear-wave velocity in upper 30 m (Vs30) of soil in Bhaktapur district in the eastern part of the Kathmandu Basin at 73 observation points, employing two methods involving the use of non-invasive microtremor array measurements (MAMs). These MAMs are widely used for determining subsurface soil characteristics by analyzing the ambient vibrations of the ground. The first method involves inversion using a genetic algorithm, and the second is a method for obtaining Vs30 directly from the dispersion curve. We found that Vs30 in the southeastern part of the study area was higher than that in other parts. Conversely, Vs30 in the western region was lower. The calculated Vs30 values were used to classify the sites. The elevated eastern and southeastern areas with high Vs30 were categorized as dense soil or soft rock, whereas the areas with low Vs30 that had suffered significant damage during the 2015 Gorkha earthquake were classified as soft soil sites. Graphical Abstract |
| format | Article |
| id | doaj-art-0b93abf5b3ee41f790cf09c2245db1ad |
| institution | OA Journals |
| issn | 1880-5981 |
| language | English |
| publishDate | 2024-10-01 |
| publisher | SpringerOpen |
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| series | Earth, Planets and Space |
| spelling | doaj-art-0b93abf5b3ee41f790cf09c2245db1ad2025-08-20T02:11:24ZengSpringerOpenEarth, Planets and Space1880-59812024-10-0176111410.1186/s40623-024-02077-6Estimation of Vs30 and site classification of Bhaktapur district, Nepal using microtremor array measurementRoshan Prajapati0Salim Dhonju1Subeg Man Bijukchhen2Michiko Shigefuji3Nobuo Takai4Postgraduate Department of Earthquake Engineering, Khwopa Engineering College, Purbanchal UniversityPostgraduate Department of Earthquake Engineering, Khwopa Engineering College, Purbanchal UniversityResearch and Development Unit, Khwopa Engineering College, Purbanchal UniversityKyushu UniversityHokkaido UniversityAbstract The severe damage observed in the Kathmandu Basin, Nepal, during past earthquakes necessitates a thorough study of the seismic behavior of the basin sediments. As the shear-wave velocity is directly related to the elastic shear modulus of the material, it is essential to determine it to incorporate the behavior of the soil in the design of the structure. Hence, we determined average shear-wave velocity in upper 30 m (Vs30) of soil in Bhaktapur district in the eastern part of the Kathmandu Basin at 73 observation points, employing two methods involving the use of non-invasive microtremor array measurements (MAMs). These MAMs are widely used for determining subsurface soil characteristics by analyzing the ambient vibrations of the ground. The first method involves inversion using a genetic algorithm, and the second is a method for obtaining Vs30 directly from the dispersion curve. We found that Vs30 in the southeastern part of the study area was higher than that in other parts. Conversely, Vs30 in the western region was lower. The calculated Vs30 values were used to classify the sites. The elevated eastern and southeastern areas with high Vs30 were categorized as dense soil or soft rock, whereas the areas with low Vs30 that had suffered significant damage during the 2015 Gorkha earthquake were classified as soft soil sites. Graphical Abstracthttps://doi.org/10.1186/s40623-024-02077-6Microtremor array measurementVs30Spatial autocorrelation methodPhase velocity dispersion curveSite classification |
| spellingShingle | Roshan Prajapati Salim Dhonju Subeg Man Bijukchhen Michiko Shigefuji Nobuo Takai Estimation of Vs30 and site classification of Bhaktapur district, Nepal using microtremor array measurement Earth, Planets and Space Microtremor array measurement Vs30 Spatial autocorrelation method Phase velocity dispersion curve Site classification |
| title | Estimation of Vs30 and site classification of Bhaktapur district, Nepal using microtremor array measurement |
| title_full | Estimation of Vs30 and site classification of Bhaktapur district, Nepal using microtremor array measurement |
| title_fullStr | Estimation of Vs30 and site classification of Bhaktapur district, Nepal using microtremor array measurement |
| title_full_unstemmed | Estimation of Vs30 and site classification of Bhaktapur district, Nepal using microtremor array measurement |
| title_short | Estimation of Vs30 and site classification of Bhaktapur district, Nepal using microtremor array measurement |
| title_sort | estimation of vs30 and site classification of bhaktapur district nepal using microtremor array measurement |
| topic | Microtremor array measurement Vs30 Spatial autocorrelation method Phase velocity dispersion curve Site classification |
| url | https://doi.org/10.1186/s40623-024-02077-6 |
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