scholarly journals Empirical Correlations between Cumulative Absolute Velocity and Amplitude-Based Ground Motion Intensity Measures

2012 ◽  
Vol 28 (1) ◽  
pp. 37-54 ◽  
Author(s):  
Brendon A. Bradley
Keyword(s):  
Ground Motion ◽  
Common Ground ◽  
Low Frequency ◽  
Peak Ground Velocity ◽  
Absolute Velocity ◽  
Response Analysis ◽  
Earthquake Rupture ◽  
Intensity Measures ◽  
Cumulative Absolute Velocity ◽  
Spectrum Intensity

Empirical correlation equations are developed between cumulative absolute velocity ( CAV) and other common ground motion intensity measures, namely, peak ground acceleration ( PGA), peak ground velocity ( PGV), 5% damped pseudo spectral acceleration ( SA), acceleration spectrum intensity ( ASI), spectrum intensity ( SI), and displacement spectrum intensity ( DSI). It is found that, for a given earthquake rupture, CAV has the strongest correlation with high and moderate frequency intensity measures (IMs), that is, ASI, PGA, PGV and high-frequency SA, and to a lesser extent with low frequency IMs ( DSI and low-frequency SA). The largest positive correlations of approximately 0.7 however are not high in an absolute sense, a result of the cumulative nature of CAV. The equations allow estimation of the joint distribution of these intensity measures for a given earthquake rupture, enabling the inclusion of CAV, and its benefit as a cumulative intensity measure, in seismic hazard analysis, ground motion selection, and seismic response analysis.

Empirical Correlations between Generalized Ground-Motion Intensity Measures for Earthquakes in China

2020 ◽  
Author(s):  
Kun Ji ◽  
Yefei Ren ◽  
Ruizhi Wen
Keyword(s):  
Ground Motion ◽  
Correlation Coefficients ◽  
Parametric Models ◽  
Peak Ground Velocity ◽  
Ground Acceleration ◽  
Intensity Measures ◽  
Vibration Period ◽  
Significant Duration ◽  
Cumulative Absolute Velocity ◽  
Spectrum Intensity

ABSTRACT This study used earthquake records from China to investigate comprehensively the correlation coefficients between various intensity measures (IMs), including peak ground acceleration, peak ground velocity, spectral acceleration, spectrum intensity, acceleration spectrum intensity, Arias intensity, cumulative absolute velocity, and significant duration. After collection of metadata information, 681 three-component ground-motion recordings with magnitudes of Mw 4.9–6.9 were carefully processed and extracted from the China National Strong-Motion Observation Network System dataset (2007–2015). The applicability of both the Next Generation Attenuation (NGA)-West2 ground-motion model (GMM) and of other GMMs was verified for different IMs, regarding the China dataset. Then, empirical correlation coefficients between different IMs were computed, considering the uncertainty due to the different sample sizes of the observational data using the bootstrap sampling method and Fisher z transformation. Finally, the median values of the correlation coefficients were fitted as a continuous function of the vibration period in the range of 0.01–10.0 s and compared with the results of similar studies developed for shallow crustal regions worldwide. The developed region-specific correlation coefficient prediction model yielded tendencies approximately like those reported in other studies. However, obvious differences were found in long-period ranges of amplitude-based IMs, cumulative effect IMs, and significant duration. These results suggest the necessity of using region-specific correlation coefficients for generalized IMs in China. The presented results and parametric models could be easily implemented in a generalized IM ground-motion selection method or a vector-based probability seismic hazard analysis procedure for China.

scholarly journals Ground motion models for Arias intensity, cumulative absolute velocity, peak incremental ground velocity, and significant duration in New Zealand

2019 ◽  
Vol 52 (4) ◽  
pp. 193-207 ◽  
Author(s):  
Zach Bullock
Keyword(s):  
New Zealand ◽  
Ground Motion ◽  
Absolute Velocity ◽  
Taupo Volcanic Zone ◽  
Arias Intensity ◽  
Intensity Measures ◽  
Motion Models ◽  
Cumulative Absolute Velocity ◽  
Functional Forms ◽  
Ground Motion Models

This study proposes empirical ground motion models for a variety of non-spectral intensity measures and significant durations in New Zealand. Equations are presented for the prediction of the median and maximum rotated components of Arias intensity, cumulative absolute velocity, cumulative absolute velocity above a 5 cm/s2 acceleration threshold, peak incremental ground velocity, and the 5% to 75% and 5% to 95% significant durations. Recent research has highlighted the usefulness of these parameters in both structural and geotechnical engineering. The New Zealand Strong Motion Database provides the database for regression and includes many earthquakes from all regions of New Zealand with the exceptions of Auckland and Northland, Otago and Southland, and Taranaki. The functional forms for the proposed models are selected using cross validation. The possible influence of effects not typically included in ground motion models for these intensity measures is considered, such as hanging wall effects and basin depth effects, as well as altered attenuation in the Taupo Volcanic Zone. The selected functional forms include magnitude and rupture depth scaling, attenuation with distance, and shallow site effects. Finally, the spatial autocorrelation of the models’ within-event residuals is considered and recommendations are made for developing correlated maps of intensity predictions stochastically.

A Comparison of Ground Motion Prediction Equations for Arias Intensity and Cumulative Absolute Velocity Developed Using a Consistent Database and Functional Form

2012 ◽  
Vol 28 (3) ◽  
pp. 931-941 ◽  
Author(s):  
Kenneth W. Campbell ◽  
Yousef Bozorgnia
Keyword(s):  
Ground Motion ◽  
Functional Form ◽  
Strong Motion ◽  
Prediction Equation ◽  
Absolute Velocity ◽  
Motion Prediction ◽  
Ground Motion Prediction ◽  
Arias Intensity ◽  
Intensity Measures ◽  
Cumulative Absolute Velocity

Arias intensity (AI) and cumulative absolute velocity (CAV) have been proposed as instrumental intensity measures that can incorporate the cumulative effects of ground motion duration and intensity on the response of structural and geotechnical systems. In this study, we have developed a ground motion prediction equation (GMPE) for the horizontal component of AI in order to compare its predictability to a similar GMPE for CAV. Both GMPEs were developed using the same strong motion database and functional form in order to eliminate any bias these factors might cause in the comparison. This comparison shows that AI exhibits significantly greater amplitude scaling and aleatory uncertainty than CAV. The smaller standard deviation and less sensitivity to amplitude suggests that CAV is more predictable than AI and should be considered as an alternative to AI in engineering and geotechnical applications where the latter intensity measure is traditionally used.

Modeling spatial cross-correlation of multiple ground motion intensity measures (SAs, PGA, PGV, Ia, CAV, and significant durations) based on principal component and geostatistical analyses

2020 ◽  
pp. 875529302095244
Author(s):  
Wenqi Du ◽  
Chao-Lie Ning
Keyword(s):  
Ground Motion ◽  
Principal Components ◽  
Cross Correlation ◽  
Principal Component ◽  
Peak Ground Velocity ◽  
Large Area ◽  
Intensity Measures ◽  
Spatially Correlated ◽  
Cumulative Absolute Velocity ◽  
Proposed Model

Ground motion intensity measures (IMs) were observed to be spatially correlated during past earthquakes. In this article, a new spatial cross-correlation model for a vector-IM, which consists of spectral acceleration (SA) ordinates at 17 periods and six non-SA IMs (e.g. peak ground velocity, Arias intensity, cumulative absolute velocity, and significant durations), is proposed using principal component analysis (PCA) and geostatistical analysis. A total of 3797 ground motion records are selected from the NGA-West2 database for such analyses. PCA is used to transform the spatially correlated within-event residuals into uncorrelated principal components; a permissible function is then proposed to fit the empirical semivariograms calculated by the principal components. It is evident that the proposed model performs well in capturing the spatial variability characteristics of the multiple ground motion IMs. A simple example is presented to illustrate the use of the proposed model in realizing spatially correlated ground motion residuals of multiple IMs. The model developed enables one to simulate spatially cross-correlated IMs over a large area in a rapid way.

scholarly journals Empirical Correlations between Peak Ground Velocity and Spectrum-Based Intensity Measures

2012 ◽  
Vol 28 (1) ◽  
pp. 17-35 ◽  
Author(s):  
Brendon A. Bradley
Keyword(s):  
Ground Motion ◽  
Peak Ground Velocity ◽  
Strongly Correlated ◽  
Correlation Equations ◽  
Ground Acceleration ◽  
Intensity Measures ◽  
Ground Motion Selection ◽  
Crustal Earthquakes ◽  
Short Period ◽  
Spectrum Intensity

Empirical correlation equations between peak ground velocity ( PGV) and several spectrum-based ground motion intensity measures are developed. The intensity measures examined in particular were: peak ground acceleration ( PGA), 5% damped pseudo-spectral acceleration ( SA), acceleration spectrum intensity ( ASI), and spectrum intensity ( SI). The computed correlations were obtained using ground motions from active shallow crustal earthquakes and four ground motion prediction equations. Results indicate that PGV is strongly correlated (i.e., a correlation coefficient of [Formula: see text]) with SI, moderately correlated with medium to long-period SA (i.e., [Formula: see text] for vibration periods 0.5-3.0 seconds), and also moderately correlated with short period SA, PGA and ASI ([Formula: see text]). A simple example is used to illustrate one possible application of the developed correlation equations for ground motion selection.

Ground Motion Models for the Horizontal Components of Arias Intensity (AI) and Cumulative Absolute Velocity (CAV) Using the NGA-West2 Database

2019 ◽  
Vol 35 (3) ◽  
pp. 1289-1310 ◽  
Author(s):  
Kenneth W. Campbell ◽  
Yousef Bozorgnia
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Goodness Of Fit ◽  
Performance Metrics ◽  
Absolute Velocity ◽  
Arias Intensity ◽  
Intensity Measures ◽  
Motion Models ◽  
Cumulative Absolute Velocity ◽  
Ground Motion Models

We updated our Next Generation Attenuation (NGA)-West1 ground motion models (GMMs) for the horizontal components of Arias intensity (AI) and cumulative absolute velocity (CAV) using the functional form and NGA-West2 database we used to develop GMMs for peak-amplitude and peak-spectral ground motion intensity measures (GMIMs). Our results show that CAV has the best goodness-of-fit statistics of all the GMIMs we have evaluated up to this time. Its relatively small between- and within-event standard deviations confirm its superior predictability. On the other hand, AI has the highest standard deviation of any GMIM we have studied thus far, which is approximately double that of CAV. Although either CAV or AI or a combination of both have been shown to meet various performance metrics proposed in the context of performance-based earthquake engineering (PBEE), CAV's high level of predictability makes it superior to AI for use in engineering applications, such as PBEE, that involve probabilistic inference.

Predictive Equations to Quantify the Impact of Spectral Matching on Ground Motion Characteristics

2016 ◽  
Vol 32 (1) ◽  
pp. 125-142 ◽  
Author(s):  
Clinton Carlson ◽  
Dimitrios Zekkos ◽  
Adda Athanasopoulos-Zekkos
Keyword(s):  
Ground Motion ◽  
Response Spectrum ◽  
Time History ◽  
Peak Ground Velocity ◽  
Spectral Matching ◽  
Predictive Equations ◽  
Earthquake Scenarios ◽  
Cumulative Absolute Velocity ◽  
Motion Characteristics ◽  
The Impact

Spectral matching, the process of modifying a seed acceleration time history in intensity and frequency content until its acceleration response spectrum matches a target spectrum, is used extensively in practice. Predictive equations that quantify the impact of spectral matching on the peak ground velocity, peak ground displacement, Arias intensity, and cumulative absolute velocity of a scaled seed time history have been developed and validated on the basis of thousands of matched motions, three different earthquake scenarios, and numerous target spectra. It is found that spectral mismatch is the most critical factor affecting the changes in ground motion characteristics. The technique used for modification (e.g., time domain or frequency domain) is in many cases not critical. Based on the results, recommendations in order to minimize the impact of matching on the ground motion characteristics are provided.

Efficient Intensity Measures for Probabilistic Seismic Response Analysis of Anchored Above-Ground Liquid Steel Storage Tanks

2016 ◽  
Author(s):  
Hoang Nam Phan ◽  
Fabrizio Paolacci
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Nuclear Power ◽  
Power Plants ◽  
Seismic Analysis ◽  
Time History ◽  
Response Analysis ◽  
Storage Tanks ◽  
Intensity Measures ◽  
Study Results

Liquid storage tanks are vital lifeline structures and have been widely used in industries and nuclear power plants. In performance-based earthquake engineering, the assessment of probabilistic seismic risk of structural components at a site is significantly affected by the choice of ground motion intensity measures (IMs). However, at present there is no specific widely accepted procedure to evaluate the efficiency of IMs used in assessing the seismic performance of steel storage tanks. The study presented herein concerns the probabilistic seismic analysis of anchored above-ground steel storage tanks subjected to several sets of ground motion records. The engineering demand parameters for the analysis are the compressive meridional stress in the tank wall and the sloshing wave height of the liquid free surface. The efficiency and sufficiency of each alternative IM are quantified by results of time history analyses for the structural response and a proper regression analysis. According to the comparative study results, this paper proposes the most efficient and sufficient IMs with respect to the above demand parameters for a portfolio of anchored steel storage tanks.

Chile Strong Ground Motion Flatfile

2016 ◽  
Vol 32 (4) ◽  
pp. 2549-2566 ◽  
Author(s):  
Nicolas Bastías ◽  
Gonzalo A. Montalva
Keyword(s):  
Ground Motion ◽  
Plate Boundary ◽  
Peak Ground Velocity ◽  
South American ◽  
Ground Acceleration ◽  
Data Set ◽  
Intensity Measures ◽  
South American Plate ◽  
Rupture Plane ◽  
Illapel Earthquake

The Nazca-South American plate boundary produces large-magnitude events (Mw > 8) every 20 years on the coast of Chile. This work describes a public ground motion database that contains 3,572 records from 477 earthquakes and 181 seismic stations, which includes the recent 2015 Mw 8.3 Illapel earthquake. The data set is controlled by subduction interface and inslab events. The oldest event included is Valparaiso (1985), and the magnitude span is 4.6–8.8 Mw. The source-to-site distance metrics reported are the closest distance to the rupture plane ( R rup), epicentral ( R epi) and hypocentral ( R hyp) distances, with a range for R rup from 20 to 650 km. Site characterization is based on V S30, ranging from 110 to 1,951 m/s. Intensity measures included are peak ground acceleration, spectral acceleration values from 0.01 to 10 s, Arias intensity, and peak ground velocity. Each record was uniformly processed component by component. A flatfile with the related metadata and the spectral accelerations from processed ground motions is available at NEEShub ( http://doi.org/10.17603/DS2N30J ; Bastías and Montalva 2015 ).

Assessment Supporting the Use of Outcropping Rock Evolutionary Intensity Measures for Prediction of Liquefaction Consequences

2019 ◽  
Vol 35 (4) ◽  
pp. 1899-1926 ◽  
Author(s):  
Zach Bullock ◽  
Shideh Dashti ◽  
Abbie B. Liel ◽  
Keith A. Porter ◽  
Zana Karimi
Keyword(s):  
Peak Ground Velocity ◽  
Far Field ◽  
Intensity Measures ◽  
Cumulative Absolute Velocity ◽  
Centrifuge Models ◽  
Soil Foundation ◽  
Vector Valued ◽  
Foundation Structure ◽  
Relative Quality

This study evaluates a variety of intensity measures (IMs) for predicting the liquefaction-induced residual settlement and tilt of shallow-founded structures. We use data from both numerical and physical (centrifuge) models of soil-foundation-structure systems. The relative quality of these IMs is quantified in terms of efficiency, sufficiency, and predictability. We consider both scalar and vector-valued IMs and evaluate the relative performance of IMs recorded at different locations (outcropping rock, within rock, far-field, and foundation) from nonlinear and equivalent-linear simulations. Cumulative absolute velocity (CAV) at outcropping rock is the optimum IM for predicting foundation settlement, while either outcropping rock CAV, peak ground velocity, or peak incremental ground velocity is optimum for predicting permanent foundation tilt. Vector IMs offer improvements to efficiency and sufficiency but may be impractical to predict.

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