NGA Ground Motion Model for the Geometric Mean Horizontal Component of PGA, PGV, PGD and 5% Damped Linear Elastic Response Spectra for Periods Ranging from 0.01 to 10 s

2008 ◽  
Vol 24 (1) ◽  
pp. 139-171 ◽  
Author(s):  
Kenneth W. Campbell ◽  
Yousef Bozorgnia
Keyword(s):  
Standard Deviation ◽  
Ground Motion ◽  
Geometric Mean ◽  
Response Spectra ◽  
Horizontal Component ◽  
Elastic Response ◽  
Motion Model ◽  
Linear Elastic ◽  
Ground Motion Model ◽  
Elastic Response Spectra

We present a new empirical ground motion model for PGA, PGV, PGD and 5% damped linear elastic response spectra for periods ranging from 0.01–10 s. The model was developed as part of the PEER Next Generation Attenuation (NGA) project. We used a subset of the PEER NGA database for which we excluded recordings and earthquakes that were believed to be inappropriate for estimating free-field ground motions from shallow earthquake mainshocks in active tectonic regimes. We developed relations for both the median and standard deviation of the geometric mean horizontal component of ground motion that we consider to be valid for magnitudes ranging from 4.0 up to 7.5–8.5 (depending on fault mechanism) and distances ranging from 0–200 km. The model explicitly includes the effects of magnitude saturation, magnitude-dependent attenuation, style of faulting, rupture depth, hanging-wall geometry, linear and nonlinear site response, 3-D basin response, and inter-event and intra-event variability. Soil nonlinearity causes the intra-event standard deviation to depend on the amplitude of PGA on reference rock rather than on magnitude, which leads to a decrease in aleatory uncertainty at high levels of ground shaking for sites located on soil.

scholarly journals A Non-Ergodic Effective Amplitude Ground-Motion Model for California

2021 ◽  
Author(s):  
Grigorios Lavrentiadis ◽  
Norman A. Abrahamson ◽  
Nicolas M. Kuehn
Keyword(s):  
Standard Deviation ◽  
Ground Motion ◽  
Epistemic Uncertainty ◽  
Amplitude Spectrum ◽  
Time History ◽  
Motion Model ◽  
Small Magnitude ◽  
Varying Coefficients ◽  
Ground Motion Model ◽  
Systematic Effects

Abstract A new non-ergodic ground-motion model (GMM) for effective amplitude spectral (EAS) values for California is presented in this study. EAS, which is defined in Goulet et al. (2018), is a smoothed rotation-independent Fourier amplitude spectrum of the two horizontal components of an acceleration time history. The main motivation for developing a non-ergodic EAS GMM, rather than a spectral acceleration GMM, is that the scaling of EAS does not depend on spectral shape, and therefore, the more frequent small magnitude events can be used in the estimation of the non-ergodic terms. The model is developed using the California subset of the NGAWest2 dataset Ancheta et al. (2013). The Bayless and Abrahamson (2019b) (BA18) ergodic EAS GMM was used as backbone to constrain the average source, path, and site scaling. The non-ergodic GMM is formulated as a Bayesian hierarchical model: the non-ergodic source and site terms are modeled as spatially varying coefficients following the approach of Landwehr et al. (2016), and the non-ergodic path effects are captured by the cell-specific anelastic attenuation attenuation following the approach of Dawood and Rodriguez-Marek (2013). Close to stations and past events, the mean values of the non-ergodic terms deviate from zero to capture the systematic effects and their epistemic uncertainty is small. In areas with sparse data, the epistemic uncertainty of the non-ergodic terms is large, as the systematic effects cannot be determined. The non-ergodic total aleatory standard deviation is approximately 30 to 40% smaller than the total aleatory standard deviation of BA18. This reduction in the aleatory variability has a significant impact on hazard calculations at large return periods. The epistemic uncertainty of the ground motion predictions is small in areas close to stations and past event.

Response Modification Factor for Y-Eccentric-Braced Steel Frame Structures Designed Based on Chinese Code

2014 ◽  
Vol 580-583 ◽  
pp. 1449-1457
Author(s):  
Wen Xia Yang ◽  
Qiang Gu ◽  
Ping Zhou Cao ◽  
Rong Jin Shi
Keyword(s):  
Pushover Analysis ◽  
Design Procedure ◽  
Response Spectra ◽  
Elastic Response ◽  
Base Shear ◽  
Response Modification Factor ◽  
Linear Elastic ◽  
Elastic Response Spectra ◽  
Modification Factor ◽  
Steel Frame Structures

In current seismic design procedure, structure base shear is calculated according to the linear elastic response spectra divided by the response modification factor, which accounts for ductility and overstrength of a structural system. In this paper, the response modification factors of Y-eccentric braced steel frames (YECBF) designed based on Chinese Code were evaluated by an improved pushover analysis on 12 examples with various stories and spans lengths. According to the analysis results, the effects of fundamental periods, storey numbers, and spans of frames on the behavior factor were studied. In the end, an appropriate response modification factor was proposed for YECBF designed base on Chinese Code.

Damping Scaling Factors for Vertical Elastic Response Spectra for Shallow Crustal Earthquakes in Active Tectonic Regions

2014 ◽  
Vol 30 (3) ◽  
pp. 1335-1358 ◽  
Author(s):  
Sanaz Rezaeian ◽  
Yousef Bozorgnia ◽  
I. M. Idriss ◽  
Norman A. Abrahamson ◽  
Kenneth W. Campbell ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Damping Ratio ◽  
Vertical Component ◽  
Vertical Motion ◽  
Horizontal Component ◽  
Elastic Response ◽  
Earthquake Ground Motion ◽  
Crustal Earthquakes ◽  
Elastic Response Spectra ◽  
Active Tectonic

This paper develops a new model for a damping scaling factor (DSF) that can be used to adjust elastic response spectral ordinates for the vertical component of earthquake ground motion at a 5% viscous damping ratio to ordinates at damping ratios between 0.5% and 30%. Using the extensive NGA-West2 database of recorded ground motions from worldwide shallow crustal earthquakes in active tectonic regions, a functional form for the median DSF is proposed that depends on the damping ratio, spectral period, earthquake magnitude, and distance. Standard deviation is a function of the damping ratio and spectral period. The proposed model is compared to the DSF for the “average” horizontal component. In general, the peak in DSF is shifted toward shorter periods and is farther from unity for the vertical component. Also, the standard deviation of DSF for vertical motion is slightly higher than that observed for the “average” horizontal component.

A Referenced Empirical Ground-Motion Model for Arias Intensity and Cumulative Absolute Velocity Based on the NGA-East Database

2020 ◽  
Vol 110 (2) ◽  
pp. 508-518
Author(s):  
Ali Farhadi ◽  
Shahram Pezeshk
Keyword(s):  
Ground Motion ◽  
Reference Model ◽  
Geometric Mean ◽  
Absolute Velocity ◽  
Motion Model ◽  
Arias Intensity ◽  
Mixed Effect ◽  
Ground Motion Model ◽  
Cumulative Absolute Velocity ◽  
Proposed Model

ABSTRACT In this study, we use the referenced empirical method of Atkinson (2008) to develop a ground-motion model (GMM) for estimating Arias intensity (IA) and cumulative absolute velocity (CAV) for the central and eastern North America. We use Campbell and Bozorgnia (2019) as the reference model. To achieve the objectives of this study, we begin with computing the geometric mean of the IA and CAV from the two as-recorded horizontal components of the motion for the recording motions in the Next Generation Attenuation-East strong-motion database. Then, we calculate the residuals of Campbell and Bozorgnia (2019) reference GMM for both IA and CAV. Next, we use the mixed-effect regression approach introduced by Abrahamson and Youngs (1992) to define adjustment factors to the Campbell and Bozorgnia (2019) model. Finally, we evaluate the proposed referenced empirical model by performing a set of residual analyses and comparing model predictions with observed data. The proposed model shows no apparent residual trend for magnitude or distance and implicitly accounts for the site term using the site factors proposed by Campbell and Bozorgnia (2019) model. The valid distance and magnitude range of the proposed model is the same as the selected reference model. In addition, we consider our new model to be applicable for time-averaged shear-wave velocity in the upper 30 m (VS30) between 150 and 2000  m/s.

scholarly journals Ground-motion relations for eastern North America

1995 ◽  
Vol 85 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Gail M. Atkinson ◽  
David M. Boore
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Response Spectra ◽  
Model Parameters ◽  
Eastern North America ◽  
Motion Model ◽  
Ground Acceleration ◽  
Ground Motion Model ◽  
Definition Of ◽  
Validation Of Results

Abstract Predictive relations are developed for ground motions from eastern North American earthquakes of 4.0 ≦ M ≦ 7.25 at distances of 10 ≦ R ≦ 500 km. The predicted parameters are response spectra at frequencies of 0.5 to 20 Hz, and peak ground acceleration and velocity. The predictions are derived from an empirically based stochastic ground-motion model. The relations differ from previous work in the improved empirical definition of input parameters and empirical validation of results. The relations are in demonstrable agreement with ground motions from earthquakes of M 4 to 5. There are insufficient data to adequately judge the relations at larger magnitudes, although they are consistent with data from the Saguenay (M 5.8) and Nahanni (M 6.8) earthquakes. The underlying model parameters are constrained by empirical data for events as large as M 6.8.

scholarly journals A Non-ergodic Spectral Acceleration Ground Motion Model for California Developed with Random Vibration Theory

2021 ◽  
Author(s):  
Grigorios Lavrentiadis ◽  
Norman A. Abrahamson
Keyword(s):  
Standard Deviation ◽  
Ground Motion ◽  
Random Vibration ◽  
Epistemic Uncertainty ◽  
Response Spectrum ◽  
Motion Model ◽  
Small Magnitude ◽  
Vibration Theory ◽  
Ground Motion Model ◽  
Random Vibration Theory

Abstract A new approach for creating a non-ergodic PSA ground-motion model (GMM) is presented which account for the magnitude dependence of the non-ergodic effects. In this approach, the average PSA scaling is controlled by an ergodic PSA GMM, and the non-ergodic effects are captured with non-ergodic PSA factors, which are the adjustment that needs to be applied to an ergodic PSA GMM to incorporate the non-ergodic effects. The non-ergodic PSA factors are based on EAS non-ergodic effects and are converted to PSA through Random Vibration Theory (RVT). The advantage of this approach is that it better captures the non-ergodic source, path, and site effects through the small magnitude earthquakes. Due to the linear properties of Fourier Transform, the EAS non-ergodic effects of the small events can be applied directly to the large magnitude events. This is not the case for PSA, as response spectrum is controlled by a range of frequencies, making PSA non-ergodic effects depended on the spectral shape which is magnitude dependent. Two PSA non-ergodic GMMs are derived using the ASK14 (Abrahamson et al., 2014) and CY14 (Chiou and Youngs, 2014) GMMs as backbone models, respectively. The non-ergodic EAS effects are estimated with the LAK21 (Lavrentiadis et al., In press) GMM. The RVT calculations are performed with the V75 (Vanmarcke, 1975) peak factor model, the Da0.05−0.85 estimate of AS96 (Abrahamson and Silva, 1996) for the ground-motion duration, and BT15 (Boore and Thompson, 2015) oscillator-duration model. The California subset of the NGAWest2 database (Ancheta et al., 2014) is used for both models. The total aleatory standard deviation of the two non-ergodic PSA GMMs is approximately 30 to 35% smaller than the total aleatory standard deviation of the corresponding ergodic PSA GMMs. This reduction has a significant impact on hazard calculations at large return periods. In remote areas, far from stations and past events, the reduction of aleatory variability is accompanied by an increase of epistemic uncertainty.

scholarly journals NORMALIZED ACCELERATION RESPONSE SPECTRA FOR TBILISI CITY WITH SEISMOLOGICAL PARAMETERS AND SITE EFFECTS

2014 ◽  
Author(s):  
П.А. Реквава ◽  
К. Мдивани
Keyword(s):  
Ground Motion ◽  
Direct Method ◽  
Response Spectra ◽  
Elastic Response ◽  
Earthquake Ground Motion ◽  
Soil Conditions ◽  
Vertical Acceleration ◽  
Acceleration Time Histories ◽  
Elastic Response Spectra ◽  
Wide Range

Из-за отсутствия реальных записей сильных движений целью данного исследования является разработка методологии для быстрой генерации горизонтальных и вертикальных составляющих грунтовых движений землетрясения на любом участке для города Тбилиси. Модель, разработанная в результате исследования, обеспечивает имитацию движений грунта в широком диапазоне магнитуд и расстояний при 8 очагах землетрясений в регионе Тбилиси (в пределах 50 км). Исследование включает в себя три основные темы: 1) стохастическое моделирования грунтовых движений при землетрясении для данного участка города Тбилиси 2) оценка записей ускорения в данном участке, используя прямой метод инженерной сейсмологии, рассматривая грунтовые условия, основываясь на теории отраженных волн 3) расчет горизонтального и вертикального спектров упругой реакции ускорения для основных участков территории Тбилиси. Due to lack of the real strong ground motion records the objective of this research is to develop a methodology for rapid generation of horizontal and vertical components of earthquake ground motion at any site for Tbilisi city. The model developed in this study provides simulation of ground motion over a wide range of magnitudes and distances at 8 earthquake sources zones of Tbilisi region (within 50 km). The research includes three main topics: 1) the stochastic simulation of earthquake ground motion at a given site of the city of Tbilisi 2) the estimation of acceleration time histories at a given site using the direct method of engineering seismology considering soil conditions based on the theory of the reflected waves and 3) calculation of horizontal and vertical acceleration elastic response spectra for main sites of Tbilisi territory.

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