Relations between MaxRotD50 and Some Horizontal Components of Ground-Motion Intensity Used in Practice

2021 ◽  
Author(s):  
Alan Poulos ◽  
Eduardo Miranda
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Ground Motions ◽  
Geometric Mean ◽  
The Other ◽  
Horizontal Projection ◽  
Site Class ◽  
Engineering Research ◽  
Natural Logarithm ◽  
Horizontal Ground Motion

ABSTRACT The most commonly used intensity measure of ground motion in earthquake engineering is the 5% damped spectral ordinate, which varies in different directions. Several different measures have been proposed over the years to combine the intensity of the two horizontal recorded ground motions to derive ground-motion models as well as for design purposes. This study provides the relation to seven previously used measures of horizontal ground motion with respect to a recently proposed orientation-independent measure of horizontal ground-motion intensity referred to as MaxRotD50. This new measure of horizontal intensity is defined as the median value of the maximum spectral ordinate of two orthogonal directions computed for all possible nonredundant orientations. The relations are computed using 5065 pairs of horizontal ground motions taken from the database of ground motions recorded in shallow crustal earthquakes in active tectonic regions developed as part of the Pacific Earthquake Engineering Research Center’s Next Generation Attenuation-West2 project. Empirically derived period-dependent relations are presented for three quantities that permit transforming any of the seven other definitions of horizontal ground-motion intensity to MaxRotD50, namely, (1) geometric mean of the ratio of MaxRotD50 to any of the seven other measures of intensities, (2) standard deviation of the natural logarithm of the ratio of MaxRotD50 to any of the seven other measures of intensities, and (3) the correlation between the natural logarithm of the ratio of MaxRotD50 to the other measures of intensities and the natural logarithm of the other measure of intensity. In addition, the influence of site class at the recording station, earthquake magnitude, and distance to the horizontal projection of the rupture is examined on the geometric mean of the ratio of MaxRotD50 to the median intensity of all nonredundant orientations (i.e., RotD50), showing negligible influence of site class and only a relatively small influence of magnitude and distance.

NGA-West2 Models for Ground Motion Directionality

2014 ◽  
Vol 30 (3) ◽  
pp. 1285-1300 ◽  
Author(s):  
Shrey K. Shahi ◽  
Jack W. Baker
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Hazard Analysis ◽  
Ground Motions ◽  
Response Spectra ◽  
Engineering Research ◽  
The Pacific ◽  
Horizontal Ground Motion ◽  
Motion Directionality ◽  
The Relationship

The NGA-West2 research program, coordinated by the Pacific Earthquake Engineering Research Center (PEER), is a major effort to produce refined models for predicting ground motion response spectra. This study presents new models for ground motion directionality developed as part of that project. Using a database of recorded ground motions, empirical models have been developed for a variety of quantities related to direction-dependent spectra. A model is proposed for the maximum spectral acceleration observed in any orientation of horizontal ground motion shaking ( Sa RotD100), which is formulated as a multiplicative factor to be coupled with the NGA-West2 models that predict the median spectral accelerations over all orientations ( Sa RotD50). Models are also proposed for the distribution of orientations of the Sa RotD100 value, relative to the fault and the relationship between Sa RotD100 orientations at differing periods. Discussion is provided regarding how these results can be applied to perform seismic hazard analysis and compute realistic target spectra conditioned on different parameters.

scholarly journals Selection of Compatible Ground Motions with the Seismic Characteristics of Erbil City, the Capital of the Kurdistan Region of Iraq

2020 ◽  
Vol 10 (1) ◽  
pp. 110-120
Author(s):  
Zina A. AbdulJaleel ◽  
Bahman O. Taha
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Risk Evaluation ◽  
Ground Motions ◽  
Imperial Valley ◽  
Engineering Research ◽  
Ground Motion Selection ◽  
Seismic Characteristics ◽  
Time Histories ◽  
Selection Of

Erbil city characterized by the risk of earthquakes generated by Zagros-Taurus Belt. The central objective of this study is to obtain a compatible input ground motion within the seismicity of Erbil city since which is considered an essential component of seismic risk evaluation and vulnerability studies. The real records obtained from the online database Pacific Earthquake Engineering Research Next Generation Attenuation. Four sets of ground motion selection and modification methods proposed to obtain fifteen records, where each record scaled and matched with the defined target spectra and seismic characteristics in Erbil city. Based on the greatest number of repetition and different events, ten compatible ground motions with earthquake name and NGA record number are selected: Gazli_Ussr (#126), Imperial Vally_06 (#183), El Mayor-Cucapah_Maxico (#5827), Christchurch_New Zealand (#8124), Imperial Valley (#6), Darfield_NewZealand (#6893), Duzce Turkey (#1602), Northridge_01 (#1082), Loma Prieta (#761), and Spitak_Armenia (#730). Seismosoft application utilized to obtain the graphs of acceleration, velocity, and displacement time histories for three components, in addition to determine the important parameters to characterize the amplitude, frequency content, and duration of the selected ground motion.

The SMART I Accelerograph Array (1980-1987): A Review

1987 ◽  
Vol 3 (2) ◽  
pp. 263-287 ◽  
Author(s):  
N. A. Abrahamson ◽  
B. A. Bolt ◽  
R. B. Darragh ◽  
J. Penzien ◽  
Y. B. Tsai
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Ground Motions ◽  
Near Field ◽  
Strong Motion ◽  
Response Spectra ◽  
Transform Faults ◽  
Engineering Research ◽  
Motion Data ◽  
Time Histories

SMART 1 is the first large digital array of strong-motion seismographs specially designed for engineering and seismological studies of the generation and near-field properties of earthquakes. Since the array began operation in September 1980, it has recorded over 3000 accelerogram traces from 48 earthquakes ranging in local magnitude ( ML) from 3.6 to 7.0. Peak ground accelerations have been recorded up to 0.33g and 0.34g on the horizontal and vertical components, respectively. Epicentral distances have ranged from 3 km 200 km from the array center, and focal depths have ranged from shallow to 100 km. The recorded earthquakes had both reverse and strike-slip focal mechanisms associated with the subduction zone and transform faults. These high quality, digital, ground motions provide a varied resource for earthquake engineering research. Earthquake engineering studies of the SMART 1 ground motion data have led to advances in knowledge in several cases: for example, on frequency-dependent incoherency of free-surface ground motions over short distances, on response of linear systems to multiple support excitations, on attenuation of peak ground-motion parameters and response spectra, on site torsion and phasing effects, and on the identification of wave types. Accelerograms from individual strong-motion seismographs do not, in general, provide such information. This review describes the SMART 1 array and the recorded earthquakes with special engineering applications. Also, it tabulates the unfiltered peak array accelerations, displays some of the recorded ground motion time histories, and summarizes the main engineering research that has made use of SMART 1 data.

PEER NGA-East database

2021 ◽  
Vol 37 (1_suppl) ◽  
pp. 1331-1353
Author(s):  
Christine A Goulet ◽  
Tadahiro Kishida ◽  
Timothy D Ancheta ◽  
Chris H Cramer ◽  
Robert B Darragh ◽  
...  
Keyword(s):  
Time Series ◽  
Ground Motion ◽  
Earthquake Engineering ◽  
Ground Motions ◽  
Time Windows ◽  
Earthquake Ground Motion ◽  
Engineering Research ◽  
Ground Motion Model ◽  
Stable Continental Region ◽  
Quality Checks

This article documents the earthquake ground motion database developed for the NGA-East Project, initiated as part of the Next Generation Attenuation (NGA) research program and led by the Pacific Earthquake Engineering Research Center (PEER). The project was focused on developing a ground motion characterization model (GMC) model for horizontal ground motions for the large region referred to as Central and Eastern North America (CENA). The CENA region covers most of the U.S. and Canada, from the Rocky Mountains to the Atlantic Ocean and is characterized tectonically as a stable continental region (SCR). The ground-motion database includes the two- and three-component ground-motion recordings from numerous selected events relevant to CENA ( M > 2.5, with distances up to 3500 km) that have been recorded since 1976. The final database contains over 27,000 time series from 82 earthquakes and 1271 recording stations. The ground motion database includes uniformly processed time series, 5% damped pseudo-spectral acceleration (PSA) median-component ordinates for 429 periods ranging from 0.01 to 10 s, duration and Arias intensity in 5% increments, and Fourier amplitude spectra for different time windows. Ground motions and metadata for source, path, and site conditions were subjected to quality checks by topical working groups and the ground-motion model (GMM) developers. The NGA-East database constitutes the largest database of processed recorded ground motions in SRCs and is publicly available from the PEER ground-motion database website.

Site-Specific Design Spectra for Vertical Ground Motion

2011 ◽  
Vol 27 (4) ◽  
pp. 1023-1047 ◽  
Author(s):  
Zeynep Gülerce ◽  
Norman A. Abrahamson
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Site Response ◽  
Probabilistic Seismic Hazard Assessment ◽  
Motion Model ◽  
Engineering Research ◽  
Design Spectra ◽  
Ground Motion Model ◽  
Nonlinear Site Response ◽  
Horizontal Ground Motion

This paper contains ground-motion prediction equations (GMPEs) for the vertical-to-horizontal spectral acceleration (V/H) ratio, and the methods for constructing vertical design spectra that are consistent with the probabilistic seismic hazard assessment results for the horizontal ground motion component. The GMPEs for V/H ratio consistent with the horizontal GMPE of Abrahamson and Silva (2008) are derived using the Pacific Earthquake Engineering Research Center's Next Generation of Ground-Motion Attenuation Models (PEER-NGA) database (Chiou et. al. 2008). The proposed V/H ratio GMPE is dependent on the earthquake magnitude and distance, consistent with previous models, but it differs from previous studies in that it accounts for the differences in the nonlinear site-response effects on the horizontal and vertical components. This difference in nonlinear effects results in large V/H ratios at short spectral periods for soil sites located close to large earthquakes. A method to develop vertical design spectra dependent on the horizontal component uniform hazard spectrum that accounts for the correlation between the variability of the horizontal ground-motion model and the variability of the V/H ratio ground-motion model is proposed.

scholarly journals Quantitative Identification of Pulse-Like Ground Motions Based on Hilbert–Huang Transform

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Zhen Liu
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Ground Motions ◽  
Engineering Research ◽  
Hilbert Huang Transform ◽  
Near Fault ◽  
Identification Method ◽  
Recognition Quality ◽  
Complex Shapes ◽  
Selection Of

Aiming to address the problem of pulse-like ground motions being difficult to identify, this paper refines the Baker’s wavelet-based pulse-like ground motions identification method, followed by a new pulse-like ground motion identification method based on Hilbert–Huang Transform (HHT) being proposed. In this method, HHT is used to decompose ground motions instead of wavelet. HHT can overcome the dependence of wavelet analysis on the selection of mother wave, and thus more complex velocity pulses can be identified. In order to compare the effects of two pulse-like ground motion identification methods, HHT-based method and wavelet-based method, respectively, are used to identify ground motions in Pacific Earthquake Engineering Research Center (PEER). After identifying the 3066 groups of ground motions selected from PEER, it is found that the HHT-based method can identify 229 pulse-like ground motions, and the wavelet-based method can identify 150 pulse-like ground motions. More complex shapes of near-fault velocity pulses can be extracted by the HHT-based method. By analyzing the seismic response, fault distance, and cumulative squared velocity (CSV) of these pulse-like ground motions, it is found that the pulse-like ground motions identified by the HHT-based method have strong near-fault characteristics. If a high recognition quality can be guaranteed, the proposed HHT-based method can identify many kinds of near-fault velocity pulses and thus provide more pulse-like ground motions for seismic researches.

Conditioned Simulation of Ground-Motion Time Series at Uninstrumented Sites Using Gaussian Process Regression

2021 ◽  
Author(s):  
Aidin Tamhidi ◽  
Nicolas Kuehn ◽  
S. Farid Ghahari ◽  
Arthur J. Rodgers ◽  
Monica D. Kohler ◽  
...  
Keyword(s):  
Time Series ◽  
Gaussian Process ◽  
Ground Motion ◽  
San Francisco ◽  
Earthquake Engineering ◽  
Seismic Analysis ◽  
Ground Motions ◽  
Free Field ◽  
Gaussian Process Regression ◽  
Motion Time

ABSTRACT Ground-motion time series are essential input data in seismic analysis and performance assessment of the built environment. Because instruments to record free-field ground motions are generally sparse, methods are needed to estimate motions at locations with no available ground-motion recording instrumentation. In this study, given a set of observed motions, ground-motion time series at target sites are constructed using a Gaussian process regression (GPR) approach, which treats the real and imaginary parts of the Fourier spectrum as random Gaussian variables. Model training, verification, and applicability studies are carried out using the physics-based simulated ground motions of the 1906 Mw 7.9 San Francisco earthquake and Mw 7.0 Hayward fault scenario earthquake in northern California. The method’s performance is further evaluated using the 2019 Mw 7.1 Ridgecrest earthquake ground motions recorded by the Community Seismic Network stations located in southern California. These evaluations indicate that the trained GPR model is able to adequately estimate the ground-motion time series for frequency ranges that are pertinent for most earthquake engineering applications. The trained GPR model exhibits proper performance in predicting the long-period content of the ground motions as well as directivity pulses.

Behavior of CFST-RC Pier under Different Ground Motions

2018 ◽  
Vol 1145 ◽  
pp. 134-139
Author(s):  
Raghabendra Yadav ◽  
Bao Chun Chen ◽  
Hui Hui Yuan ◽  
Zhi Bin Lian
Keyword(s):  
Earthquake Engineering ◽  
Large Scale ◽  
Dynamic Testing ◽  
Ground Motions ◽  
Dynamic Test ◽  
Longitudinal Direction ◽  
Steel Tube ◽  
Engineering Research ◽  
Magnification Factors ◽  
Time Histories

The dynamic testing of large-scale structures continues to play a significant role in earthquake engineering research. The pseudo- dynamic test (PDT) is an experimental technique for simulating the earthquake response of structures and structural components in time domain. A CFST-RC pier is a modified form of CFST laced column in which CFST members are connected with RC web in longitudinal direction and with steel tube in transverse direction. For this study, a CFST -RC pier is tested under three different earthquake time histories having scaled PGA of 0.05g. From the experiment acceleration, velocity, displacement and load time histories are observed. The dynamic magnification factors for acceleration due to Chamoli, Gorkha and Wenchuan ground motions are observed as 12, 10 and 10 respectively. The frequency of the pier is found to be 1.42 Hz. The result shows that this type of pier has excellent static and earthquake resistant properties.

NGA-West2 Research Project

2014 ◽  
Vol 30 (3) ◽  
pp. 973-987 ◽  
Author(s):  
Yousef Bozorgnia ◽  
Norman A. Abrahamson ◽  
Linda Al Atik ◽  
Timothy D. Ancheta ◽  
Gail M. Atkinson ◽  
...  
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Research Program ◽  
Epistemic Uncertainty ◽  
Response Spectra ◽  
Site Amplification ◽  
Earthquake Hazards ◽  
Research Project ◽  
Engineering Research ◽  
Crustal Earthquakes

The NGA-West2 project is a large multidisciplinary, multi-year research program on the Next Generation Attenuation (NGA) models for shallow crustal earthquakes in active tectonic regions. The research project has been coordinated by the Pacific Earthquake Engineering Research Center (PEER), with extensive technical interactions among many individuals and organizations. NGA-West2 addresses several key issues in ground-motion seismic hazard, including updating the NGA database for a magnitude range of 3.0–7.9; updating NGA ground-motion prediction equations (GMPEs) for the “average” horizontal component; scaling response spectra for damping values other than 5%; quantifying the effects of directivity and directionality for horizontal ground motion; resolving discrepancies between the NGA and the National Earthquake Hazards Reduction Program (NEHRP) site amplification factors; analysis of epistemic uncertainty for NGA GMPEs; and developing GMPEs for vertical ground motion. This paper presents an overview of the NGA-West2 research program and its subprojects.

Prediction of Ground-Motion Parameters for the NGA-West2 Database Using Refined Second-Order Deep Neural Networks

2021 ◽  
Author(s):  
Duofa Ji ◽  
Chenxi Li ◽  
Changhai Zhai ◽  
You Dong ◽  
Evangelos I. Katsanos ◽  
...  
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Hazard Analysis ◽  
A Priori ◽  
Absolute Error ◽  
Second Order ◽  
Prediction Errors ◽  
Intensity Measures ◽  
Engineering Research ◽  
Motion Models

ABSTRACT One of the key elements within seismic hazard analysis is the establishment of appropriate ground-motion models (GMMs), which are used to predict the levels of ground-motion intensities by considering various parameters (e.g., source, path, and site). Many empirical GMMs were derived on the basis of a predefined linear or nonlinear equation that is heavily dependent on the a priori knowledge of a functional form that varies between the modelers’ choices. To overcome this issue, this study develops a deep neural network (DNN) trained by the recordings from the Pacific Earthquake Engineering Research Center (PEER) Next Generation Attenuation-West2 Project (NGA-West2) database. To this end, we collected 20,900 ground motion recordings from the database and randomly split them into the training, validation, and testing datasets. The refined second-order neuron is proposed to solve the problem, and the Adam optimizer is used to optimize the performance of the model. The prediction errors are evaluated by three performance indicators (i.e., R2, root mean square error, mean absolute error), and the predictive results are compared with previous GMMs developed based on the PEER NGA-West2 database. The between-event and within-event standard deviations (SDs) as well as total SDs are calculated and compared. Based on the comparisons, our model maintains consistent performance (e.g., the dependence of predicted intensity measures on seismological and site-specific parameters) with the compared GMM. Its relatively small total SDs, especially for longer periods, confirm that the proposed model is associated with better predictive power.

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