Sensitivity of the strong ground motion time histories to a finite source model: A case study for the January 12, 2010 Haiti earthquake (Mw=7.0)

2011 ◽  
Vol 31 (11) ◽  
pp. 1441-1451 ◽  
Author(s):  
Nurcan Meral Özel ◽  
Ebru Harmandar ◽  
Ali Pınar
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Source Model ◽  
Haiti Earthquake ◽  
Finite Source ◽  
Motion Time ◽  
Time Histories ◽  
Strong Ground

Selection and Scaling Time History Records for Performance-Based Design

2017 ◽  
pp. 1-35
Author(s):  
Yasin M. Fahjan ◽  
F. İlknur Kara ◽  
Aydın Mert
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Time History ◽  
Design Code ◽  
Uniform Hazard Spectra ◽  
Acceleration Time ◽  
Acceleration Time Histories ◽  
Recent Developments ◽  
Time Histories ◽  
Strong Ground

Recent developments in performance-based analyses and the high performance of computational facilities have led to an increased trend for utilizing nonlinear time-history analysis in seismic evaluation of the performance of structures. One of the crucial issues of such analysis is the selection of appropriate acceleration time histories set that satisfy design code requirements at a specific site. In literature, there are three sources of acceleration time histories: 1) recorded accelerograms in real earthquakes scaled to match design code spectrum/uniform hazard spectra/conditional mean spectrum, 2) artificial records generated from white noise spectra to satisfy design code spectrum, and 3) synthetic records obtained from seismological models. Due to the increase of available strong ground motion database, using and scaling real recorded accelerograms is becoming one of the most contemporary research issues in this field. In this study, basic methodologies and criteria for selecting strong ground motion time histories are discussed. Design code requirements for scaling are summarized for ASCE/SEI-7-10, EC8 and Turkish Seismic Codes. Examples for scaling earthquake records to uniform hazard spectra are provided.

High-Frequency Spectral Decay Characteristics of Seismic Records of Inland Crustal Earthquakes in Japan: Evaluation of the fmax and κ Models

2020 ◽  
Vol 110 (2) ◽  
pp. 452-470
Author(s):  
Masato Tsurugi ◽  
Reiji Tanaka ◽  
Takao Kagawa ◽  
Kojiro Irikura
Keyword(s):  
Ground Motion ◽  
High Frequency ◽  
Strong Ground Motion ◽  
Cutoff Frequency ◽  
Source Model ◽  
Power Coefficient ◽  
Crustal Earthquakes ◽  
Log Linear ◽  
Large Earthquakes ◽  
Strong Ground

ABSTRACT We examined high-frequency spectral decay characteristics of ground motions for inland crustal earthquakes in Japan, which are important in strong ground motion predictions. We examined 105 earthquakes (Mw 3.3–7.1), including seven large earthquakes (Mw 5.9–7.1). Spectral decay characteristics were accurately evaluated assuming the ω-squared source model and using two approaches: the fmax model (commonly used in Japan), described by the cutoff frequency fmax and the power coefficient of spectral decay s, and the κ model (commonly used in worldwide), the exponential spectral decay model, described by the parameter κ and the specific frequency fE at which a spectrum starts to decrease linearly with increasing frequency in log–linear space. For large earthquakes, we estimated fmax to range from 6.5 to 9.9 Hz and s from 0.78 to 1.60 in the fmax model, and κ to range from 0.014 to 0.051 s and fE from 2 to 4.5 Hz in the κ model. In both approaches, we found that the spectral decay characteristics are regionally dependent. fmax in the fmax model and fE in the κ model tended to be smaller for large earthquakes than for moderate and small earthquakes, clearly demonstrating a seismic moment dependency. We confirmed positive correlations between equivalent parameters of the two approaches, that is, between s and κ and between fmax and fE. Moreover, we found that both approaches are appropriate for evaluating spectral decay characteristics, as long as the spectral decay parameters are appropriately evaluated by comparison with observed spectra. We examined the effects of the spectral decay characteristics on strong ground motion predictions, and demonstrated that simulated motions corrected using the fmax model and those corrected using the κ model are almost the same. The results presented in this article contribute to improving predictions of high-frequency strong ground motion.

Suitability of Synthesized Waveforms for Seismic Qualification of Equipment

1984 ◽  
Vol 106 (1) ◽  
pp. 63-68 ◽  
Author(s):  
D. D. Kana ◽  
D. J. Pomerening
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Ground Level ◽  
Frequency Content ◽  
Gaussian Random Process ◽  
Earthquake Excitation ◽  
Acceleration Time Histories ◽  
Time Histories ◽  
Orthogonal Components ◽  
Strong Ground

Qualification of nuclear plant equipment and components can be performed by analysis, test, or a combination of both. It is often required to synthesize artificial time histories which represent earthquake excitation at either ground level, or some elevated level of a structure. A set of parameters appropriate for the synthesis of acceleration time histories is developed. The parameters are based on a study of six typical earthquake accelerograms, and include general characteristics of the motion, a definition of strong ground motion, frequency content, stationarity, coherence between orthogonal components, and amplitude probability density. It is concluded that the strong ground motion can be approximated by a stationary Gaussian random process, whose frequency content depends on the ground or elevated position of concern. Coherence between orthogonal components is low at ground level, but can become high at elevated structural levels due to coupled responses. Some examples are given for application of the parameters to qualification by testing, as a means of achieving better satisfaction of existing criteria.

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