Utilization of Site-Based Simulated Ground Motions for Hazard-Targeted Seismic Demand Estimation: Application for Ordinary Bridges in Southern California

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.

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Simulation of response spectrum-compatible ground motions using wavelet-based multi-resolution analysis

Measurement and Control ◽

10.1177/00202940211013057 ◽

2021 ◽

pp. 002029402110130

Author(s):

Guan Chen ◽

Zhiren Zhu ◽

Jun Hu

Keyword(s):

Ground Motion ◽

Response Spectrum ◽

Ground Motions ◽

Power Spectra ◽

Simulation Method ◽

Eurocode 8 ◽

Effective Response ◽

Multi Resolution Analysis ◽

Resolution Analysis ◽

Simulated Ground Motions

This study proposed a simple and effective response spectrum-compatible ground motions simulation method to mitigate the scarcity of ground motions on seismic hazard analysis base on wavelet-based multi-resolution analysis. The feasibility of the proposed method is illustrated with two recorded ground motions in El Mayor-Cucapah earthquake. The results show that the proposed method enriches the ground motions exponentially. The simulated ground motions agree well with the attenuation characteristics of seismic ground motion without modulating process. Moreover, the pseudo-acceleration response spectrum error between the recorded ground motion and the average of the simulated ground motions is 5.2%, which fulfills the requirement prescribed in Eurocode 8 for artificially simulated ground motions. Besides, the cumulative power spectra between the simulated and recorded ground motions agree well on both high- and low-frequency regions. Therefore, the proposed method offers a feasible alternative in enriching response spectrum-compatible ground motions, especially on the regions with insufficient ground motions.

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Simulation of Palu IV Bridge Collapse using Near-Fault Ground Motions

IABSE Congress, New York, New York 2019: The Evolving Metropolis ◽

10.2749/newyork.2019.1314 ◽

2019 ◽

Author(s):

Iswandi Imran ◽

Budi Santoso ◽

Ary Pramudito ◽

Muhammad Kadri Zamad

Keyword(s):

Spatial Variation ◽

Ground Motions ◽

Time History ◽

Seismic Demand ◽

Fault Line ◽

Near Fault ◽

Failure Simulation ◽

Bridge Collapse ◽

Pulse Type ◽

Bridge Bearing

<p>The earthquake near Palu, Sulawesi (Indonesia) on September 28, 2018 with a magnitude of M7.4 was caused by a shallow strike-slip of Palu-Koro fault. The earthquake and the subsequent tsunami have caused the collapse of the Ponulele Bridge (Palu IV Bridge). The steel box bowstring arch bridge was located near-fault regions (within 1,5 km from fault line) that have not been identified during the design process. This bridge may have been damaged by the presence of fling-step pulses in the near-fault pulse-type ground motions that increases the damaging potential of such ground motions. This paper presents the failure simulation of the bridge subjected to the near fault pulse type time history with spatial variation ground motions applied on multiple bridge supports. From the simulation, it is concluded that the near fault effects and the spatial variation of the ground motion have increased significantly the seismic demand on the bridge. This increase causes the failure in the anchorage of the bridge bearing system.</p>

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Evaluation of Earthquake Response Spectra Directionality Using Stochastic Simulations

Bulletin of the Seismological Society of America ◽

10.1785/0120210101 ◽

2021 ◽

Author(s):

Alan Poulos ◽

Eduardo Miranda ◽

Jack W. Baker

Keyword(s):

Stochastic Process ◽

Ground Motion ◽

Ground Motions ◽

Gaussian White Noise ◽

Response Spectra ◽

Orientation Dependence ◽

Stochastic Simulations ◽

Earthquake Ground Motion ◽

Significant Duration ◽

Simulated Ground Motions

ABSTRACT For earthquake-resistant design purposes, ground-motion intensity is usually characterized using response spectra. The amplitude of response spectral ordinates of horizontal components varies significantly with changes in orientation. This change in intensity with orientation is commonly known as ground-motion directionality. Although this directionality has been attributed to several factors, such as topographic irregularities, near-fault effects, and local geologic heterogeneities, the mechanism behind this phenomenon is still not well understood. This work studies the directionality characteristics of earthquake ground-motion intensity using synthetic ground motions and compares their directionality to that of recorded ground motions. The two principal components of horizontal acceleration are sampled independently using a stochastic model based on finite-duration time-modulated filtered Gaussian white-noise processes. By using the same stochastic process to sample both horizontal components of motion, the variance of horizontal ground acceleration has negligible orientation dependence. However, these simulations’ response spectral ordinates present directionality levels comparable to those found in real ground motions. It is shown that the directionality of the simulated ground motions changes for each realization of the stochastic process and is a consequence of the duration being finite. Simulated ground motions also present similar directionality trends to recorded earthquake ground motions, such as the increase of average directionality with increasing period of vibration and decrease with increasing significant duration. These results suggest that most of the orientation dependence of horizontal response spectra is primarily explained by the finite significant duration of earthquake ground motion causing inherent randomness in response spectra, rather than by some physical mechanism causing polarization of shaking.

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Validation of stochastic ground motion model modification by comparison to seismic demand of recorded ground motions

Bulletin of Earthquake Engineering ◽

10.1007/s10518-019-00571-x ◽

2019 ◽

Vol 17 (6) ◽

pp. 2871-2898 ◽

Cited By ~ 3

Author(s):

Alexandra Tsioulou ◽

Alexandros A. Taflanidis ◽

Carmine Galasso

Keyword(s):

Ground Motion ◽

Ground Motions ◽

Seismic Demand ◽

Motion Model ◽

Model Modification ◽

Ground Motion Model

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Analysis of the Seismic Demand of High-Performance Buckling-Restrained Braces under a Strong Earthquake and Its Aftershocks

Advances in Civil Engineering ◽

10.1155/2019/1482736 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14 ◽

Cited By ~ 5

Author(s):

Luqi Xie ◽

Jing Wu ◽

Qing Huang ◽

Chao Tong

Keyword(s):

Plastic Deformation ◽

Ground Motion ◽

Strong Earthquake ◽

High Performance ◽

Hazard Analysis ◽

Ground Motions ◽

Threshold Value ◽

Seismic Demand ◽

Near Fault ◽

Probabilistic Seismic Demand

The analysis of the ductility and cumulative plastic deformation (CPD) demand of a high-performance buckling-restrained brace (HPBRB) under a strong earthquake and its aftershocks is conducted in this paper. A combination of three continuous excitations with the same ground motion is used to simulate the affection of a strong earthquake and its aftershocks. A six-story HPBRB frame (HPBRBF) is taken as an example to conduct the incremental dynamic analysis (IDA). The seismic responses of the HPBRBF under one, two, and three constant continuous ground motions are compared. The IDA result indicates that the ductility and CPD demand of the BRBs under the three constant continuous ground motions are significantly larger than that excited by only one. Probabilistic seismic demand analysis (PSDA) is performed using seven near-fault ground motions and seven far-fault ground motions to consider the indeterminacy of ground motion. The probabilistic seismic demand curves (PSDCs) for the ductility and CPD demand for the HPBRB under the strong earthquake and its aftershocks are obtained in combining the probabilistic seismic hazard analysis. The results indicate that the AISC threshold value of the CPD with 200 is excessively low for a HPBRBF which suffers the continuous strong aftershocks with near-fault excitations, and a stricter threshold value should be suggested to ensure the ductility and plastic deformation capacity demand of the HPBRB.

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