Study on real-time correction of site amplification factor
<p>The site amplification factor was usually considered to be scalar values, such as amplification of peak ground acceleration or peak ground velocity, or increments of seismic intensity in the earthquake early warning (EEW) system or seismic-intensity repaid report system. This paper focuses...
Main Authors: | , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2019-12-01
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Series: | Natural Hazards and Earth System Sciences |
Online Access: | https://www.nat-hazards-earth-syst-sci.net/19/2827/2019/nhess-19-2827-2019.pdf |
Summary: | <p>The site amplification factor was usually considered to be
scalar values, such as amplification of peak ground acceleration or peak
ground velocity, or increments of seismic intensity in the earthquake early
warning (EEW) system or seismic-intensity repaid report system. This paper focuses
on evaluating an infinite impulse recursive filter method that could produce
frequency-dependent site amplification and compare the performance of the
scalar-value method with the infinite impulse recursive filter method. A
large number of strong motion data of IBRH10 and IBRH19 of the Kiban Kyoshin
network (KiK-net) triggered in more than 1000 earthquakes from 2004
to 2012 were selected carefully and used to obtain the relative site
amplification ratio; we model the relative site amplification factor with a
casual filter. Then we make a simulation from the borehole to the surface and also
simulate from the front-detection station to the far-field station. Compared to
different simulation cases, it can easily be found that this method could
produce different amplification factors for different earthquakes and could
reflect the frequency-dependent nature of site amplification. Through these
simulations between two stations, we can find that the frequency-dependent
correction for site amplification shows better performance than the amplification factor relative to velocity (ARV)
method and station correction method. It also shows better performance than
the average level and the highest level of the Japan Meteorological Agency (JMA)
earthquake early warning system in ground motion prediction. Some cases in which simulation
did not work very well were also found; possible reasons and
problems were analyzed and addressed. This method pays attention to the
amplitude and ignores the phase characteristics; this problem may be improved
by the seismic-interferometry method. Frequency-dependent correction for
site amplification in the time domain highly improves the accuracy of
predicting ground motion in real time.</p> |
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ISSN: | 1561-8633 1684-9981 |