scholarly journals Effects of the Predominant Pulse on the Inelastic Displacement Ratios of Pulse-Like Ground Motions Based on Wavelet Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Guochen Zhao ◽  
Jingzhou Zhu ◽  
Xingji Zhu ◽  
Longjun Xu
Keyword(s):  
Wavelet Analysis ◽  
Ground Motion ◽  
Ground Motions ◽  
Soil Condition ◽  
Analysis Method ◽  
Arias Intensity ◽  
Pulse Period ◽  
New Model ◽  
Inelastic Displacement ◽  
Pulse Intensity

Having a predominant pulse is the main feature for pulse-like ground motions differing from others. To investigate the influence of the predominant pulse on the inelastic displacement ratios of pulse-like ground motions, the wavelet analysis method is used to extract the predominant pulse. The results indicate that the inelastic displacement ratios of the pulse-removed parts obtained by subtracting the extracted pulse from the original pulse-like ground motions are close to the results of non-pulse-like ground motions. The ratio of the energy of the extracted pulse to the energy of the original ground motion is used to represent the pulse intensity. The results indicate that the pulse period determines the locations in which the inelastic displacement ratios would have noticeable increments, and the pulse intensity determines the degree of the increments. Besides, the effects of five commonly used parameters (PGV, PGD, PGV/PGA, Arias intensity Ia, and soil condition) on the inelastic displacement ratios of pulse-like ground motions and their relations to the pulse period and the pulse intensity are studied. Finally, a new model, in which the influence of pulse intensity is considered, to predict the inelastic displacement ratios of pulse-like ground motions is proposed.

scholarly journals Simulation of non-stationary stochastic ground motions based on recent Italian earthquakes

2021 ◽  
Author(s):  
Fabio Sabetta ◽  
Antonio Pugliese ◽  
Gabriele Fiorentino ◽  
Giovanni Lanzano ◽  
Lucia Luzi
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Strong Motion ◽  
Stochastic Simulations ◽  
Model Parameters ◽  
Motion Model ◽  
Arias Intensity ◽  
Time Frequency ◽  
Ground Motion Model ◽  
Ground Motion Records

AbstractThis work presents an up-to-date model for the simulation of non-stationary ground motions, including several novelties compared to the original study of Sabetta and Pugliese (Bull Seism Soc Am 86:337–352, 1996). The selection of the input motion in the framework of earthquake engineering has become progressively more important with the growing use of nonlinear dynamic analyses. Regardless of the increasing availability of large strong motion databases, ground motion records are not always available for a given earthquake scenario and site condition, requiring the adoption of simulated time series. Among the different techniques for the generation of ground motion records, we focused on the methods based on stochastic simulations, considering the time- frequency decomposition of the seismic ground motion. We updated the non-stationary stochastic model initially developed in Sabetta and Pugliese (Bull Seism Soc Am 86:337–352, 1996) and later modified by Pousse et al. (Bull Seism Soc Am 96:2103–2117, 2006) and Laurendeau et al. (Nonstationary stochastic simulation of strong ground-motion time histories: application to the Japanese database. 15 WCEE Lisbon, 2012). The model is based on the S-transform that implicitly considers both the amplitude and frequency modulation. The four model parameters required for the simulation are: Arias intensity, significant duration, central frequency, and frequency bandwidth. They were obtained from an empirical ground motion model calibrated using the accelerometric records included in the updated Italian strong-motion database ITACA. The simulated accelerograms show a good match with the ground motion model prediction of several amplitude and frequency measures, such as Arias intensity, peak acceleration, peak velocity, Fourier spectra, and response spectra.

An NGA Model for the Average Horizontal Component of Peak Ground Motion and Response Spectra

2008 ◽  
Vol 24 (1) ◽  
pp. 173-215 ◽  
Author(s):  
BrianS-J. Chiou ◽  
Robert R. Youngs
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Hanging Wall ◽  
Response Spectra ◽  
Horizontal Component ◽  
Smooth Functions ◽  
Soil Response ◽  
New Model ◽  
Crustal Earthquakes ◽  
Aleatory Variability

We present a model for estimating horizontal ground motion amplitudes caused by shallow crustal earthquakes occurring in active tectonic environments. The model provides predictive relationships for the orientation-independent average horizontal component of ground motions. Relationships are provided for peak acceleration, peak velocity, and 5-percent damped pseudo-spectral acceleration for spectral periods of 0.01 to 10 seconds. The model represents an update of the relationships developed by Sadigh et. al. (1997) and incorporates improved magnitude and distance scaling forms as well as hanging-wall effects. Site effects are represented by smooth functions of average shear wave velocity of the upper 30 m ( VS30) and sediment depth. The new model predicts median ground motion that is similar to Sadigh et. al. (1997) at short spectral period, but lower ground motions at longer periods. The new model produces slightly lower ground motions in the distance range of 10 to 50 km and larger ground motions at larger distances. The aleatory variability in ground motion amplitude was found to depend upon earthquake magnitude and on the degree of nonlinear soil response, For large magnitude earthquakes, the aleatory variability is larger than found by Sadigh et. al. (1997).

Ground Motion Intensity Measures for Liquefaction Hazard Evaluation

2006 ◽  
Vol 22 (2) ◽  
pp. 413-438 ◽  
Author(s):  
Steven L. Kramer ◽  
Robert A. Mitchell
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Ground Motions ◽  
Excess Pore Pressure ◽  
Hazard Evaluation ◽  
Peak Acceleration ◽  
Intensity Measure ◽  
Arias Intensity ◽  
Intensity Measures ◽  
Liquefaction Hazard

The requirements of performance-based earthquake engineering place increasing importance on the optimal characterization of earthquake ground motions. With respect to liquefaction hazard evaluation, ground motions have historically been characterized by a combination of peak acceleration and earthquake magnitude, and more recently by Arias intensity. This paper introduces a new ground motion intensity measure, CAV5, and shows that excess pore pressure generation in potentially liquefiable soils is considerably more closely related to CAV5 than to other intensity measures, including peak acceleration and Arias intensity. CAV5 is shown to be an efficient, sufficient, and predictable intensity measure for rock motions used as input to liquefaction hazard evaluations. An attenuation relationship for CAV5 is presented and used in an example that illustrates the benefits of scaling bedrock motions to a particular value of CAV5, rather than to the historical intensity measures, for performance-based evaluation of liquefaction hazards.

scholarly journals Characteristics of strong ground motion attenuation in the 2019 Mw 5.8 Changning earthquake, Sichuan, China

2021 ◽  
Author(s):  
J. J. Hu ◽  
H. Zhang ◽  
J. B. Zhu ◽  
G. H. Liu
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Response Spectra ◽  
Peak Ground Velocity ◽  
Arias Intensity ◽  
Ground Acceleration ◽  
Motion Models ◽  
Ground Motion Attenuation ◽  
Short Period ◽  
Strong Ground

AbstractA moderate magnitude earthquake with Mw 5.8 occurred on June 17, 2019, in Changning County, Sichuan Province, China, causing 13 deaths, 226 injuries, and serious engineering damage. This earthquake induced heavier damage than earthquakes of similar magnitude. To explain this phenomenon in terms of ground motion characteristics, based on 58 sets of strong ground motions in this earthquake, the peak ground acceleration (PGA), peak ground velocity (PGV), acceleration response spectra (Sa), duration, and Arias intensity are analyzed. The results show that the PGA, PGV, and Sa are larger than the predicted values from some global ground motion models. The between-event residuals reveal that the source effects on the intermediate-period and long-period ground motions are stronger than those on short-period ground motions. Comparison of Arias intensity attenuation with the global models indicates that the energy of ground motions of the Changning earthquake is larger than those of earthquakes with the same magnitude.

Earthquake Ground Motions: Implications for Designing Structures and Reconciling Structural Damage

1985 ◽  
Vol 1 (2) ◽  
pp. 239-270 ◽  
Author(s):  
Jogeshwar P. Singh
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Ground Motions ◽  
Strong Motion ◽  
Soil Condition ◽  
Dominant Factor ◽  
Soil Conditions ◽  
Earthquake Ground Motions ◽  
Geological Conditions ◽  
Strong Ground

Until recently, characteristics of strong ground motion resulting from different soil conditions were considered the dominant factor in developing design ground motions and reconciling observed damage. Interpretation of recent recordings of earthquakes by strong motion instrument arrays installed in California and Taiwan show that basic characteristics of strong motion are greatly influenced by the seismological and geological conditions. For a given soil condition, the characteristics of strong ground motion (peak ground acceleration, peak ground velocity, peak ground displacement, duration, spectral content, and time histories) can vary significantly whether the site is near or far from the seismic source. As local soil conditions only modify the ground motions produced by a given source, variability in ground motion due to seismologic and geologic conditions (for a given soil condition) must be considered in estimating earthquake ground motions for structural design or for estimating structural vulnerabilities to reconcile earthquake-related damage.

Explicit Directivity-Pulse Inclusion in Probabilistic Seismic Hazard Analysis

2007 ◽  
Vol 23 (4) ◽  
pp. 867-891 ◽  
Author(s):  
Polsak Tothong ◽  
C. Allin Cornell ◽  
J. W. Baker
Keyword(s):  
Probability Distribution ◽  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Analysis ◽  
Ground Motions ◽  
Probabilistic Seismic Hazard Analysis ◽  
Seismic Hazard Analysis ◽  
Probabilistic Seismic Hazard ◽  
Pulse Period ◽  
Near Fault

Probabilistic seismic hazard analysis (PSHA) is widely used to estimate the ground motion intensity that should be considered when assessing a structure's performance. Disaggregation of PSHA is often used to identify representative ground motions in terms of magnitude and distance for structural analysis. Forward directivity–induced velocity pulses, which may occur in near-fault (or near-source) motions, are known to cause relatively severe elastic and inelastic response in structures of certain periods. Here, the principles of PSHA are extended to incorporate the possible occurrence of a velocity pulse in a near-fault ground motion. For each magnitude and site-source geometry, the probability of occurrence of a pulse is considered along with the probability distribution of the pulse period given that a pulse does occur. A near-source “narrowband” attenuation law modification to predict ground motion spectral acceleration ( Sa) amplitude that takes advantage of this additional pulse period information is utilized. Further, disaggregation results provide the probability that a given level of ground motion intensity is caused by a pulse-like ground motion, as well as the conditional probability distribution of the pulse period associated with that ground motion. These extensions improve the accuracy of PSHA for sites located near faults, as well as provide a rational basis for selecting appropriate near-fault ground motions to be used in the dynamic analyses of a structure.

Inelastic response spectra of self-centering structures with the flag-shaped hysteretic response subjected to near-fault pulse-type ground motions

2021 ◽  
pp. 875529302110003
Author(s):  
Huihui Dong ◽  
Qiang Han ◽  
Xiuli Du ◽  
Shoushan Cheng ◽  
Haifang He
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Response Spectra ◽  
Displacement Velocity ◽  
Hysteretic Behavior ◽  
Hysteretic Model ◽  
Inelastic Response ◽  
Inelastic Displacement ◽  
Near Fault ◽  
Pulse Type

Many studies on the inelastic response spectra have mainly focused on structures with the conventional hysteretic behavior. However, for self-centering structures with the flag-shaped (FS) hysteretic behavior, the corresponding study is limited. The primary aim of this study is to investigate the inelastic response spectra of self-centering structures with FS hysteretic behavior subjected to the near-fault pulse-type ground motion. To this end, the smooth FS hysteretic model based on Bouc–Wen model is developed, and the characteristics of pulse-type ground motions are described in detail. It is found that the general features of inelastic response spectra of the FS model are sensitive to the acceleration-, velocity-, and displacement-sensitive spectral regions of the ground motion. The inelastic displacement, velocity, acceleration, and ductility factor spectra of the FS hysteretic model for pulse-type ground motions are much larger than those for ordinary ground motions, while the residual displacement spectra under the two types of ground motions are both very small due to its self-centering capacity. Moreover, the inelastic response spectra are affected by the ground motion characteristics and structural hysteresis behavior, especially the large pulse period and peak ground velocity (PGV) significantly increase the inelastic displacement, velocity, and acceleration spectra.

A subset of CyberShake ground-motion time series for response-history analysis

2021 ◽  
pp. 875529302098197
Author(s):  
Jack W Baker ◽  
Sanaz Rezaeian ◽  
Christine A Goulet ◽  
Nicolas Luco ◽  
Ganyu Teng
Keyword(s):  
Time Series ◽  
Los Angeles ◽  
Seismic Hazard ◽  
Ground Motion ◽  
Ground Motions ◽  
Response Spectra ◽  
Motion Time ◽  
History Analysis ◽  
Response History Analysis ◽  
Simulated Ground Motions

This manuscript describes a subset of CyberShake numerically simulated ground motions that were selected and vetted for use in engineering response-history analyses. Ground motions were selected that have seismological properties and response spectra representative of conditions in the Los Angeles area, based on disaggregation of seismic hazard. Ground motions were selected from millions of available time series and were reviewed to confirm their suitability for response-history analysis. The processes used to select the time series, the characteristics of the resulting data, and the provided documentation are described in this article. The resulting data and documentation are available electronically.

Ground-motion model for subduction earthquakes in northern South America

2021 ◽  
pp. 875529302110275
Author(s):  
Carlos A Arteta ◽  
Cesar A Pajaro ◽  
Vicente Mercado ◽  
Julián Montejo ◽  
Mónica Arcila ◽  
...  
Keyword(s):  
South America ◽  
Ground Motion ◽  
Ground Motions ◽  
Strong Motion ◽  
Motion Prediction ◽  
Depth Range ◽  
Ground Motion Prediction ◽  
Natural Period ◽  
Nazca Plate ◽  
Northern South America

Subduction ground motions in northern South America are about a factor of 2 smaller than the ground motions for similar events in other regions. Nevertheless, historical and recent large-interface and intermediate-depth slab earthquakes of moment magnitudes Mw = 7.8 (Ecuador, 2016) and 7.2 (Colombia, 2012) evidenced the vast potential damage that vulnerable populations close to earthquake epicenters could experience. This article proposes a new empirical ground-motion prediction model for subduction events in northern South America, a regionalization of the global AG2020 ground-motion prediction equations. An updated ground-motion database curated by the Colombian Geological Survey is employed. It comprises recordings from earthquakes associated with the subduction of the Nazca plate gathered by the National Strong Motion Network in Colombia and by the Institute of Geophysics at Escuela Politécnica Nacional in Ecuador. The regional terms of our model are estimated with 539 records from 60 subduction events in Colombia and Ecuador with epicenters in the range of −0.6° to 7.6°N and 75.5° to 79.6°W, with Mw≥4.5, hypocentral depth range of 4 ≤  Zhypo ≤ 210 km, for distances up to 350 km. The model includes forearc and backarc terms to account for larger attenuation at backarc sites for slab events and site categorization based on natural period. The proposed model corrects the median AG2020 global model to better account for the larger attenuation of local ground motions and includes a partially non-ergodic variance model.

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