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Seismic hazard analysis in the last few decades has become a very important issue. Recently, new technologies and available
data have been improved that have helped many scientists to understand where and why earthquakes happen, the physics of earthquakes,
etc. Scientists have begun to understand the role of uncertainty in seismic hazard analysis. However, how to handle existing
uncertainty is still a significant problem. The same lack of information causes difficulties in quantifying uncertainty accurately.
Usually, attenuation curves are obtained in a statistical manner: regression analysis. Statistical and probabilistic analyses
show overlapping results for the site coefficients. This overlapping takes place not only at the border between two neighboring
classes but also among more than three classes. Although the analysis starts from classifying sites using geological terms,
these site coefficients are not classified at all. In the present study, this problem is solved using fuzzy set theory. Using
membership functions, the ambiguities at the border between neighboring classes can be avoided. Fuzzy set theory is performed
for southern California in the conventional way. In this study, standard deviations that show variations between each site
class obtained by fuzzy set theory and the classical manner are compared. Results of this analysis show that when we have
insufficient data for hazard assessment, site classification based on fuzzy set theory shows values of standard deviations
less than those obtained using the classical way, which is direct proof of less uncertainty. 相似文献
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Teimuraz Matcharashvili Tamaz Chelidze Zurab Javakhishvili Nato Jorjiashvili Natalia Zhukova 《Acta Geophysica》2012,60(3):809-832
Investigation of dynamical features of ambient seismic noise is one of the important scientific and practical research challenges.
We investigated scaling features of the ambient noises at the Oni seismic station, Georgia, using detrended fluctuation analysis
method. Data from this seismic station, located in the epicentral zone of Oni M6.0, 2009, earthquake, were selected to include time periods with different levels of local seismic activity. 相似文献
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Teimuraz Matcharashvili Tamaz Chelidze Zurab Javakhishvili Natalia Zhukova Nato Jorjiashvili Ia Shengelia 《Acta Geophysica》2013,61(6):1659-1676
Investigation of complex dynamics of ambient seismic noise remains as an important scientific research challenge. In this work we investigated dynamical features of the ambient noises at Oni seismic station, Georgia. We used stochastic model reconstruction method from measured data sets. Seismic records for different time periods around Oni seismic station have been analysed. It was shown that the dynamics of fluctuations of seismic noise vertical component undergoes essential changes for considered time period from 2005 to 2012. These changes are more noticeable for time periods of preparation and aftershock activity of strong M6.0 earthquake occurred in 2009 in the vicinity of Oni seismic station. 相似文献
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Ground motion prediction equations based on shallow crustal earthquakes in Georgia and the surrounding Caucasus 
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下载免费PDF全文 Jorjiashvili Nato Shengelia Ia Godoladze Tea Gunia Irakli Akubardia Dimitri 《地震科学（英文版）》2022,35(6):497-509
Strong ground motions caused by earthquakes with magnitudes ranging from 3.5 to 6.9 and hypocentral distances of up to 300 km were recorded by local broadband stations and three-component accelerograms within Georgia’s enhanced digital seismic network. Such data mixing is particularly effective in areas where strong ground motion data are lacking. The data were used to produce models based on ground-motion prediction equations (GMPEs), one benefit of which is that they take into consideration information from waveforms across a wide range of frequencies. In this study, models were developed to predict ground motions for peak ground acceleration and 5%-damped pseudo-absolute-acceleration spectra for periods between 0.01 and 10 s. Short-period ground motions decayed faster than long-period motions, though decay was still in the order of approximately 1/r. Faulting mechanisms and local soil conditions greatly influence GMPEs. The spectral acceleration (SA) of thrust faults was higher than that for either strike-slip or normal faults but the influence of strike-slip faulting on SA was slightly greater than that for normal faults. Soft soils also caused significantly more amplification than rocky sites. 相似文献
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