scholarly journals Seismological and Engineering Demand Misfits for Evaluating Simulated Ground Motion Records

2019 ◽  
Vol 9 (21) ◽  
pp. 4497 ◽  
Author(s):  
Shaghayegh Karimzadeh
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Goodness Of Fit ◽  
Structural Response ◽  
Evaluation Methodology ◽  
Engineering Practice ◽  
Input Energy ◽  
Structural Demand ◽  
Ground Motion Records ◽  
Descriptive Set

Simulated ground motions have recently gained more attention in seismology and earthquake engineering. Since different characteristics of waveforms are expected to influence alternative structural response parameters, evaluation of simulations, for key components of seismological and engineering points of view is necessary. When seismological aspect is of concern, consideration of a representative set of ground motion parameters is imperative. Besides, to test the applicability of simulations in earthquake engineering, structural demand parameters should simultaneously cover a descriptive set. Herein, simulations are evaluated through comparison of seismological against engineering misfits, individually defined in terms of log-scale misfit and goodness-of-fit score. For numerical investigations, stochastically simulated records of three earthquakes are considered: The 1992 Erzincan-Turkey, 1999 Duzce-Turkey and 2009 L’Aquila-Italy events. For misfit evaluation, seismological parameters include amplitude, duration and frequency content, while engineering parameters contain spectral acceleration, velocity and seismic input energy. Overall, the same trend between both misfits is observed. All misfits for Erzincan and Duzce located on basins are larger than those corresponding to L’Aquila mostly placed on stiff sites. The engineering misfits, particularly in terms of input energy measures, are larger than seismological misfits. In summary, the proposed misfit evaluation methodology seems useful to evaluate simulations for engineering practice.

Comparison of Peak Ductility Demand of Inelastic SDOF Systems in Maximum Elastic Response and Major Principal Directions

2012 ◽  
Vol 28 (1) ◽  
pp. 385-399 ◽  
Author(s):  
Katsuichiro Goda
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Principal Direction ◽  
Elastic Response ◽  
Engineering Practice ◽  
Ductility Demand ◽  
Demand Models ◽  
Principal Directions ◽  
Ground Motion Records ◽  
Orientation Dependency

This study investigates the orientation dependency of the peak ductility demand of inelastic single-degree-of-freedom (SDOF) systems of known strengths by taking the record-to-record variability of seismic effects into account. The probabilistic characteristics of the peak ductility demand in recording directions on the horizontal plane are compared with those in the maximum elastic response direction and the major principal direction. The analysis results indicate that the peak ductility demand depends on how input ground motions are defined in terms of record orientation. The observed orientation dependency can be explained by noting the response spectral shapes of scaled ground motion records in specific directions. The results have important implications for current earthquake engineering practice, suggesting that separate peak ductility demand models should be used for different ground motion directions to evaluate the seismic performance of structures consistently and without bias.

scholarly journals An approach to quantify the influence of ground motion uncertainty on elastoplastic system acceleration in incremental dynamic analysis

2017 ◽  
Vol 20 (11) ◽  
pp. 1744-1756 ◽  
Author(s):  
Peng Deng ◽  
Shiling Pei ◽  
John W. van de Lindt ◽  
Hongyan Liu ◽  
Chao Zhang
Keyword(s):  
Dynamic Analysis ◽  
Ground Motion ◽  
Earthquake Engineering ◽  
Structural Response ◽  
Incremental Dynamic Analysis ◽  
Degree Of Freedom ◽  
Maximum Acceleration ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Performance Based Earthquake Engineering

Inclusion of ground motion–induced uncertainty in structural response evaluation is an essential component for performance-based earthquake engineering. In current practice, ground motion uncertainty is often represented in performance-based earthquake engineering analysis empirically through the use of one or more ground motion suites. How to quantitatively characterize ground motion–induced structural response uncertainty propagation at different seismic hazard levels has not been thoroughly studied to date. In this study, a procedure to quantify the influence of ground motion uncertainty on elastoplastic single-degree-of-freedom acceleration responses in an incremental dynamic analysis is proposed. By modeling the shape of the incremental dynamic analysis curves, the formula to calculate uncertainty in maximum acceleration responses of linear systems and elastoplastic single-degree-of-freedom systems is constructed. This closed-form calculation provided a quantitative way to establish statistical equivalency for different ground motion suites with regard to acceleration response in these simple systems. This equivalence was validated through a numerical experiment, in which an equivalent ground motion suite for an existing ground motion suite was constructed and shown to yield statistically similar acceleration responses to that of the existing ground motion suite at all intensity levels.

Ground Motion Intensity Measures for Rocking Building Systems

2017 ◽  
Vol 33 (4) ◽  
pp. 1533-1554 ◽  
Author(s):  
Mehrdad Shokrabadi ◽  
Henry V. Burton
Keyword(s):  
Ground Motion ◽  
Structural Response ◽  
Ground Acceleration ◽  
Intensity Measures ◽  
Braced Frame ◽  
Residual Drift ◽  
Engineering Demand Parameter ◽  
Frame System ◽  
Ground Motion Records ◽  
Steel Braced Frame

This paper investigates the effectiveness of various ground motion intensity measures (IMs) in estimating the structural response of two types of rocking systems: (a) a controlled rocking steel braced frame system with self-centering action and (b) a rocking spine system for reinforced concrete infill frames. The IMs are evaluated based on the dispersion in engineering demand parameter (EDP) predictions (efficiency) and the sensitivity of the conditional distributions of EDPs to the distributions of the magnitudes, distances and spectral shape parameter (ε) of ground motion records (sufficiency). The EDPs include maximum transient and residual story drifts and peak floor accelerations. The spectral acceleration averaged over a range of periods (Sa avg) is most effective for predicting transient and residual drift demands and peak ground acceleration (PGA) is generally the best predictor of peak floor accelerations. The proximity of the frequency range most affecting an EDP to that best reflected in an IM is found to be a good indicator of the performance of that IM.

Ground Motion Record Selection Based on Broadband Spectral Compatibility

2014 ◽  
Vol 30 (4) ◽  
pp. 1427-1448 ◽  
Author(s):  
Chiara Smerzini ◽  
Carmine Galasso ◽  
Iunio Iervolino ◽  
Roberto Paolucci
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Time History ◽  
Strong Motion ◽  
Software Tool ◽  
Engineering Practice ◽  
Ongoing Research ◽  
Research Activities ◽  
Record Selection ◽  
Ground Motion Record Selection

The increasing interest in performance-based earthquake engineering has promoted research on the improvement of hazard-consistent seismic input definition and on advanced criteria for strong motion record selection to perform nonlinear time history analyses. Within the ongoing research activities to improve the representation of seismic actions and to develop tools as a support for engineering practice, this study addresses the selection of displacement-spectrum-compatible real ground motions, with special reference to Italy. This involved (1) the definition of specific target displacement spectra for Italian sites, constrained—both at long and short periods—by results of probabilistic seismic hazard analyses; (2) the compilation of a high-quality strong ground motion database; and (3) the development of a software tool for computer-aided displacement-based record selection. Application examples show that sets of unscaled, or lightly scaled, accelerograms with limited record-to-record spectral variability can also easily be obtained when a broadband spectral compatibility is required.

Drift Spectrum vs. Modal Analysis of Structural Response to Near-Fault Ground Motions

2001 ◽  
Vol 17 (2) ◽  
pp. 221-234 ◽  
Author(s):  
Anil K. Chopra ◽  
Chatpan Chintanapakdee
Keyword(s):  
Earthquake Engineering ◽  
Response Spectrum ◽  
Ground Motions ◽  
Structural Response ◽  
Response Spectra ◽  
Engineering Practice ◽  
Drift Spectrum ◽  
Combination Rules ◽  
Near Fault ◽  
Far Fault

A new measure of earthquake demand, the drift spectrum has been developed as an adjunct to the response spectrum, a central concept in earthquake engineering, in calculating the internal deformations of a structure due to near-fault ground motions with pronounced coherent pulses in the velocity and displacement histories. Compared in this paper are certain aspects of the elastic structural response to near-fault and far-fault ground motions. It is demonstrated that (1) the difference between drift and response spectra are not unique to near-fault ground motions; these differences simply reflect higher-mode response, which is larger due to near-fault ground motions; (2) response spectrum analysis (RSA) using existing modal combination rules can provide an estimate of structural response that is accurate to a useful degree; (3) these modal combination rules are similarly accurate for near-fault and far-fault ground motions although the underlying assumptions are not satisfied by near-fault excitations; and (4) RSA is preferable over the drift spectrum in computing structural response because it represents standard engineering practice and is applicable to a wide variety of structures.

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.

Design Ground Motion Library: An Interactive Tool for Selecting Earthquake Ground Motions

2015 ◽  
Vol 31 (2) ◽  
pp. 617-635 ◽  
Author(s):  
Gang Wang ◽  
Robert Youngs ◽  
Maurice Power ◽  
Zhihua Li
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Response Spectrum ◽  
Time History ◽  
Earthquake Ground Motion ◽  
Engineering Practice ◽  
Period Range ◽  
Engineering Research ◽  
Interactive Tool ◽  
Design Response Spectrum

The Design Ground Motion Library (DGML) is an interactive tool for selecting earthquake ground motion time histories based on contemporary knowledge and engineering practice. It was created from a ground motion database that consists of 3,182 records from shallow crustal earthquakes in active tectonic regions rotated to fault-normal and fault-parallel directions. The DGML enables users to construct design response spectra based on Next-Generation Attenuation (NGA) relationships, including conditional mean spectra, code spectra, and user-specified spectra. It has the broad capability of searching for time history record sets in the database on the basis of the similarity of a record's response spectral shape to a design response spectrum over a user-defined period range. Selection criteria considering other ground motion characteristics and user needs are also provided. The DGML has been adapted for online application by the Pacific Earthquake Engineering Research Center (PEER) and incorporated as a beta version on the PEER database website.

scholarly journals Optimal Design of Liquid Dampers for Structural Vibration Control Based on GA andH∞Norm

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Linsheng Huo ◽  
Wenhe Shen ◽  
Hongnan Li ◽  
Yaowen Zhang
Keyword(s):  
Optimal Design ◽  
Ground Motion ◽  
Structural Response ◽  
Optimal Solution ◽  
Time History ◽  
Optimization Procedure ◽  
Structural Vibration ◽  
Earthquake Excitation ◽  
Liquid Dampers ◽  
Ground Motion Records

This paper focused on the optimal design of liquid dampers for the seismic response control of structures. TheH∞norm of the transfer function from the ground motion to the structural response is selected as the optimal objective. The optimization procedure is carried out by using Genetic Algorithms (GAs) in order to reach an optimal solution. The proposed method has the advantages that it is unnecessary to solve the equation of motion for the control system and that the obtained optimal parameters of dampers are not dependent on the ground motion records. The influences of weighted functions on the optimization results are analyzed. The generality and effeteness of the proposed method are verified by the time history analysis of a 3-story structure subjected to earthquake records in different sites. The results show that the structural responses can be effectively reduced subjected to earthquake excitation at different sites.

Analysis of Near-Source Ground Motion from the 2019 Ridgecrest Earthquake Sequence

2020 ◽  
Vol 110 (4) ◽  
pp. 1495-1505 ◽  
Author(s):  
Georgios Baltzopoulos ◽  
Lucia Luzi ◽  
Iunio Iervolino
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Ground Motions ◽  
Strong Motion ◽  
Rupture Directivity ◽  
Surface Rupture ◽  
Ground Acceleration ◽  
Ground Motion Records ◽  
Manual Classification ◽  
Forward Rupture Directivity

ABSTRACT The Ridgecrest seismic sequence began on 4 July 2019 in California, on a hitherto relatively unmapped orthogonal cross-faulting system, causing mainly nonstructural or liquefaction-related damage to buildings in the vicinity of Ridgecrest and Trona, and also causing substantial surface rupture. The present study considers the near-source ground-acceleration recordings collected during the two principal events of the sequence—the 4 July moment-magnitude M 6.4 foreshock and the 6 July M 7.1 mainshock—to identify pulse-like ground motions, which may have arisen due to forward rupture directivity. Pulse-like seismic input is of particular interest to earthquake engineering due to its peculiar spectral shape and possibly increased damaging potential, and expanding the strong-motion databases with such records is a topical issue. In this context, a pulse identification methodology is implemented, partially based on computer-aided signal processing, but also involving manual classification. Nine ground-motion records were classified as pulse-like by this procedure. Further investigation led to the conclusion that, for some of these records, the impulsive characteristics could most likely be attributable to forward rupture directivity, whereas for others fling step may have also been an issue. Finally, clear signs of directionality were observed in these ground motions at periods near the pulse duration, manifesting as a polarization of the spectral ordinates toward the orientation of the impulsive component.

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