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| Titel |
Estimation of empirical site amplification factors in Taiwan |
| VerfasserIn |
Chi-Hsuan Chung, Kuo-Liang Wen, Chun-Hsiang Kuo |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250140131
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| Publikation (Nr.) |
 EGU/EGU2017-3479.pdf |
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| Zusammenfassung |
| Lots of infrastructures are under construction in metropolises in Taiwan in recent years and
thus leads to increasement of population density and urbanization in those area. Taiwan island
is located in plate boundaries in which the high seismicity is caused by active tectonic plates.
The Chi-Chi earthquake (Mw 7.6) in 1999 caused a fatality of more than 2000, and the
Meinong earthquake (Mw 6.5) in 2016 caused a fatality of 117 in Tainan city as well as
damages on hundreds of buildings. The cases imply seismic vulnerability of urban
area. During the improvements for seismic hazard analysis and seismic design,
consideration of seismic site amplifications in different site conditions is one of important
issues.
This study used selected and processed strong motion records observed by the TSMIP
network. The site conditions considered as Vs30 used in this study were investigated
at most stations (Kuo et al. 2012; Kuo et al. 2016). Since strong motion records
and site conditions are both available, we are able to use the data to analyze site
amplifications of seismic waves at different periods. The result may be a reference for future
modification of seismic design codes to decrease potential seismic hazards and
losses.
We adopted the strong motion and site database of the SSHAC (Senior Seismic Hazard
Analysis Committee) Level 3 project in Taiwan. The selected significant crustal and
subduction events of magnitude larger than six for analysis. The amplification factors of
PGA, PGV, PGD, and spectra acceleration at 0.3, 1.0, and 3.0 seconds were evaluated using
the processed strong motions. According to the recommendation of SSHAC Level 3 project,
the site condition of Vs30 = 760 m/s is considered as the reference rock site in
this study. The stations with Vs30 between 600 m/s and 900 m/s and used as the
reference rock sites in reality. For each event, we find a reference rock site and other
site within a certain distance (region dependent) to calculate site amplifications of
ground motions. Relationships of site amplification factors and Vs30 are therefore
derived for strong motions by regression analysis. Soil nonlinearity (decrease of
amplifications) has to be considered at soft soil sites during a strong shaking. We also
discuss amplification factors in terms of different intensities if data is available. |
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