Response spectral matching of horizontal ground motion components to an orientation-independent spectrum (RotDnn)

2020 ◽  
pp. 875529302097098
Author(s):  
Luis A Montejo
Keyword(s):  
Ground Motion ◽  
Response Spectrum ◽  
Time History ◽  
Response Spectra ◽  
Major Axis ◽  
Component Level ◽  
Nonlinear Characteristics ◽  
Target Spectrum ◽  
Horizontal Ground Motion ◽  
Median Spectrum

This article presents a methodology to spectrally match two horizontal ground motion components to an orientation-independent target spectrum (RotDnn). The algorithm is based on the continuous wavelet transform decomposition and iterative manipulation of the two horizontal components of a seed record. The numerical examples presented follow current ASCE/SEI 7 specifications and therefore maximum-direction spectra (RotD100) are used as target for the match. However, the proposed methodology can be used to match other RotDnn spectra, like the median spectrum (RotD50). It is shown that with the proposed methodology the resulting RotDnn from the modified horizontal components closely match the smooth target RotDnn spectrum, while the response spectrum for each horizontal component continue to exhibit a realistic jagged behavior. The response spectra variability at the component level within suites of spectrally matched motions was found to be of the same order than the variability measured in suites composed of amplitude scaled records. Moreover, the spectrally matched records generated preserved most of the characteristics of the seed records, including the nonlinear characteristics of the time history traces and the period-dependent major axis orientations.

scholarly journals Site-Specific Response Spectra: Guidelines for Engineering Practice

CivilEng ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 712-735
Author(s):  
Yiwei Hu ◽  
Nelson Lam ◽  
Prashidha Khatiwada ◽  
Scott Joseph Menegon ◽  
Daniel T. W. Looi
Keyword(s):  
Ground Motion ◽  
Response Spectrum ◽  
Time History ◽  
Response Spectra ◽  
Engineering Practice ◽  
Site Classification ◽  
Specific Response ◽  
Potential Cost ◽  
Site Specific ◽  
Real Behavior

Code response spectrum models, which are used widely in the earthquake-resistant design of buildings, are simple to apply but they do not necessarily represent the real behavior of an earthquake. A code response spectrum model typically incorporates ground motion behavior in a diversity of earthquake scenarios affecting the site and does not represent any specific earthquake scenario. The soil amplification phenomenon is also poorly represented, as the current site classification scheme contains little information over the potential dynamic response behavior of the soil sediments. Site-specific response spectra have the merit of much more accurately representing real behavior. The improvement in accuracy can be translated into significant potential cost savings. Despite all the potential merits of adopting site-specific response spectra, few design engineers make use of these code provisions that have been around for a long time. This lack of uptake of the procedure by structural designers is related to the absence of a coherent set of detailed guidelines to facilitate practical applications. To fill in this knowledge gap, this paper aims at explaining the procedure in detail for generating site-specific response spectra for the seismic design or assessment of buildings. Surface ground motion accelerograms generated from the procedure can also be employed for nonlinear time-history analyses where necessary. A case study is presented to illustrate the procedure in a step-by-step manner.

The motion and damping of buildings relative to seismic response spectra

1970 ◽  
Vol 60 (1) ◽  
pp. 231-259 ◽  
Author(s):  
John A. Blume
Keyword(s):  
Ground Motion ◽  
Fundamental Mode ◽  
Response Spectrum ◽  
Spectral Response ◽  
Time History ◽  
Response Spectra ◽  
Mode Shapes ◽  
System Response ◽  
Building Motion ◽  
Actual Response

abstract The response spectrum is very useful in dynamic analysis even though its use for multimass systems involves approximations as to modal combinations. It is especially useful in predicting effects of possible real earthquakes or of proposed nuclear detonations because it may be postulated or predicted much more readily than a complete time history of ground motion. The relationships of multimass system response—in terms of displacement, velocity, acceleration, force, shear, and moment—to elastic spectral response are given, together with examples taken from the AEC nuclear testing program in Nevada. The effects of relative building stiffnesses and stiffness taper on mode shape and thus on response are shown, as are the base shears relative to spectral response for several idealized fundamental mode shapes. A Spectral Response Reconciliation procedure is presented and demonstrated by which procedure spectral response is reconciled with measured real building motion to obtain damping or other data under actual response to ground motion of any intensity. Damping values of highrise buildings are determined by this procedure. Comparisons are made between 5 per cent damped response spectral values at the fundamental mode period of buildings and measured building motion.

scholarly journals A Multi-Objective Ground Motion Selection Approach Matching the Acceleration and Displacement Response Spectra

2018 ◽  
Vol 10 (12) ◽  
pp. 4659 ◽  
Author(s):  
Yabin Chen ◽  
Longjun Xu ◽  
Xingji Zhu ◽  
Hao Liu
Keyword(s):  
Ground Motion ◽  
Response Spectrum ◽  
Structural Response ◽  
Response Spectra ◽  
Computationally Efficient ◽  
Ground Motion Selection ◽  
Displacement Response ◽  
Rc Frames ◽  
Selection Approach ◽  
Displacement Response Spectra

For seismic resilience-based design (RBD), a selection of recorded time histories for dynamic structural analysis is usually required. In order to make individual structures and communities regain their target functions as promptly as possible, uncertainty of the structural response estimates is in great need of reduction. The ground motion (GM) selection based on a single target response spectrum, such as acceleration or displacement response spectrum, would bias structural response estimates leading significant uncertainty, even though response spectrum variance is taken into account. In addition, resilience of an individual structure is not governed by its own performance, but depends severely on the performance of other systems in the same community. Thus, evaluation of resilience of a community using records matching target spectrum at whole periods would be reasonable because the fundamental periods of systems in the community may be varied. This paper presents a GM selection approach based on a probabilistic framework to find an optimal set of records to match multiple target spectra, including acceleration and displacement response spectra. Two major steps are included in that framework. Generation of multiple sub-spectra from target displacement response spectrum for selecting sets of GMs was proposed as the first step. Likewise, the process as genetic algorithm (GA), evolvement of individuals previously generated, is the second step, rather than using crossover and mutation techniques. A novel technique improving the match between acceleration response spectra of samples and targets is proposed as the second evolvement step. It is proved computationally efficient for the proposed algorithm by comparing with two developed GM selection algorithms. Finally, the proposed algorithm is applied to select GM records according to seismic codes for analysis of four archetype reinforced concrete (RC) frames aiming to evaluate the influence of GM selection considering two design response spectra on structural responses. The implications of design response spectra especially the displacement response spectrum and GM selection algorithm are summarized.

scholarly journals Preliminary results of ground-motion characteristics

2012 ◽  
Vol 55 (4) ◽  
Author(s):  
Francesca Bozzoni ◽  
Carlo Giovanni Lai ◽  
Laura Scandella
Keyword(s):  
Ground Motion ◽  
Site Response ◽  
Response Spectrum ◽  
Field Tests ◽  
Response Spectra ◽  
Ground Acceleration ◽  
Preliminary Results ◽  
Emilia Earthquake ◽  
Particle Orbit ◽  
2012 Emilia Earthquake

The preliminary results are presented herein for the engineering applications of the characteristics of the ground motion induced by the May 20, 2012, Emilia earthquake. Shake maps are computed to provide estimates of the spatial distribution of the induced ground motion. The signals recorded at the Mirandola (MRN) station, the closest to the epicenter, have been processed to obtain acceleration, velocity and displacement response spectra. Ground-motion parameters from the MRN recordings are compared with the corresponding estimates from recent ground-motion prediction equations, and with the spectra prescribed by the current Italian Building Code for different return periods. The records from the MRN station are used to plot the particle orbit (hodogram) described by the waveform. The availability of results from geotechnical field tests that were performed at a few sites in the Municipality of Mirandola prior to this earthquake of May 2012 has allowed preliminary assessment of the ground response. The amplification effects at Mirandola are estimated using fully stochastic site-response analyses. The seismic input comprises seven actual records that are compatible with the Italian code-based spectrum that refers to a 475-year return period. The computed acceleration response spectrum and the associated dispersion are compared to the spectra calculated from the recordings of the MRN station. Good agreement is obtained for periods up to 1 s, especially for the peak ground acceleration. For the other periods, the spectral acceleration of the MRN recordings exceeds that of the computed spectra.<br />

Response of higherise buildings to ground motion from underground nuclear detonations

1969 ◽  
Vol 59 (6) ◽  
pp. 2343-2370
Author(s):  
John A. Blume
Keyword(s):  
Ground Motion ◽  
Las Vegas ◽  
Spectral Response ◽  
Vertical Plane ◽  
Time History ◽  
Tall Buildings ◽  
Response Spectra ◽  
Statistical Parameters ◽  
Typical Data ◽  
Earthquake Design

abstract Typical data obtained thus far in the AEC nuclear test program on the response of highrise Las Vegas buildings to ground motion from distant nuclear events including Boxcar and Benham are presented, together with measured building response to distant earthquakes and to wind gusts. Major variations in response spectra are shown over the city for a specific event, from period band to period band at the same location for different events, and statistical parameters are shown for the randomness of spectral response. The peak response of tall buildings is shown for the top levels in translation and in orbital motion, and in the vertical plane with simultaneous multi-level measurements. The variation of peak modal response is shown with elapsed time, modal combinations are noted, and an example of time-history computed response is compared to measured response. It is shown that highrise Las Vegas buildings respond to ground motion with considerable amplification, that the fundamental modes tend to dominate the peak responses although there are exceptions, that there can be significant modification of loading conditions because of simultaneous motion in the two horizontal axes even though a building is symmetric, and that some building periods vary with amplitude and history of non-damaging prior response while others do not. In general there are indications that code earthquake design criteria are by no means conservative.

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.

A horizontal ground-motion model for crustal and subduction earthquakes in Taiwan

2020 ◽  
Vol 36 (2) ◽  
pp. 463-506 ◽  
Author(s):  
Shu-Hsien Chao ◽  
Brian Chiou ◽  
Chiao-Chu Hsu ◽  
Po-Shen Lin
Keyword(s):  
Ground Motion ◽  
Hazard Analysis ◽  
Response Spectrum ◽  
Likelihood Method ◽  
Biased Sampling ◽  
Motion Model ◽  
Subduction Earthquakes ◽  
Ground Motion Model ◽  
Single Station ◽  
Horizontal Ground Motion

In this study, a new horizontal ground-motion model is developed for crustal and subduction earthquakes in Taiwan. A novel two-step maximum-likelihood method is used as a regression tool to develop this model. This method simultaneously considers both the correlation between records and the biased sampling because of random truncation. Moreover, additional ground-motion data can be considered to derive more reliable analysis results. The functional form of the proposed ground-motion model is constructed using the response spectrum of the reference ground-motion scenario and different scalings of the source, path, and site to illustrate the ground-motion characteristics. The variabilities in the ground-motion intensity that result from different events, stations, and records are developed individually to derive a single-station sigma. The proposed ground-motion model may be useful for predicting ground-motion intensity and performing site-specific probabilistic seismic hazard analysis in Taiwan.

An Improved Source Model for Simulation Near-Field Strong Ground Motion Acceleration Time History

2013 ◽  
Vol 438-439 ◽  
pp. 1474-1480
Author(s):  
Ju Fang Zhong ◽  
Long Wei Zhang ◽  
Jun Wei Liang
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Response Spectrum ◽  
Near Field ◽  
Time History ◽  
Source Spectrum ◽  
Acceleration Time ◽  
Acceleration Time History ◽  
Spectrum Model ◽  
Strong Ground

The key to near-field strong ground motion simulation based on stochastic finite fault method is to determine the spectrum of ground motion. We present an improved source spectrum model for simulation near-field strong ground motion acceleration time history. We combine Masudas source spectrum model with scaling factor Hij to keep radiation energy conservation and reflect the energy decrease with frequency at low to mid frequencies. We calculate the Fourier amplitude spectrum Fa, accelerate response spectrum Sa, velocity response spectrum Sv and displacement response spectrum Sd of simulation time histories. By comparative analysis of the laws of spectrum values (Fa, Sa, Sv, Sd) with the variation of frequency or period, we discusses the effects of sub-fault dividing scheme, the method of determining scale factor and source spectrum model on spectrum values (Fa, Sa, Sv, Sd). The results show that sub-fault dividing scheme has slightly effect on the model presented in this paper, and the model enable to reflect the sink laws of source spectrum value in mid-to-low frequencies well. We demonstrate that the improved model is superior to other commonly used models.

Update of the Chiou and Youngs NGA Model for the Average Horizontal Component of Peak Ground Motion and Response Spectra

2014 ◽  
Vol 30 (3) ◽  
pp. 1117-1153 ◽  
Author(s):  
Brian S.-J. Chiou ◽  
Robert R. Youngs
Keyword(s):  
Ground Motion ◽  
Hanging Wall ◽  
Response Spectra ◽  
Rupture Directivity ◽  
Crustal Earthquakes ◽  
Aleatory Variability ◽  
Source Distance ◽  
Active Tectonic ◽  
Peak Ground Motion ◽  
Horizontal Ground Motion

We present an update to our 2008 NGA model for predicting horizontal ground motion amplitudes caused by shallow crustal earthquakes occurring in active tectonic environments. The update is based on analysis of the greatly expanded NGA-West2 ground motion database and numerical simulations. The updated model contains minor adjustments to our 2008 functional form related to style of faulting effects, hanging wall effects, scaling with the depth to top of rupture, scaling with sediment thickness, and the inclusion of additional terms for the effects of fault dip and rupture directivity. In addition, we incorporate regional differences in far-source distance attenuation and site effects between California and other active tectonic regions. Compared to our 2008 NGA model, the predicted medians by the updated model are similar for M > 7 and are lower for M < 5. The aleatory variability is larger than that obtained in our 2008 model.

Seismic Vulnerability Analysis of Mid-Story Isolation and Reduction Structures Based Stochastic Vibration

2011 ◽  
Vol 243-249 ◽  
pp. 3988-3991 ◽  
Author(s):  
Pei Ju Chang ◽  
Jian Zhu
Keyword(s):  
Ground Motion ◽  
Random Sample ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Response Spectrum ◽  
Time History ◽  
Time History Analysis ◽  
Good Effect ◽  
History Analysis ◽  
Reduction Effect

This study focus on derivation of such fragility curves using classic mid-story isolation and reduction structures (MIRS) in China metropolis. A set of stochastic earthquake waves compatible with the response spectrum of China seismic code selected to represent the variability in ground motion. Dynamic inelastic time history analysis was used to analyze the random sample of structures. The result reveal that good effect for superstructure and reduction effect for substructure of MIRS is favorable and obvious under major earthquake, Weak position of MIRS was be pointed out and fragility curves of typical MIRS of China was obtained finally.

Sign in / Sign up

Export Citation Format

Share Document