Calculation of long-period response spectra to earthquake ground motion from seismograms of Type 513 seismographs

1997 ◽  
Vol 10 (3) ◽  
pp. 339-346 ◽  
Author(s):  
Yan-Xiang Yu ◽  
Su-Yun Wang ◽  
Hong-Shan Lü
Keyword(s):  
Ground Motion ◽  
Response Spectra ◽  
Earthquake Ground Motion ◽  
Long Period

Evaluation of Earthquake Response Spectra Directionality Using Stochastic Simulations

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.

AN IMPROVED METHOD OF MATCHING RESPONSE SPECTRA OF RECORDED EARTHQUAKE GROUND MOTION USING WAVELETS

2006 ◽  
Vol 10 (sup001) ◽  
pp. 67-89 ◽  
Author(s):  
JONATHAN HANCOCK ◽  
JENNIE WATSON-LAMPREY ◽  
NORMAN A. ABRAHAMSON ◽  
JULIAN J. BOMMER∗ ◽  
ALEXANDROS MARKATIS ◽  
...  
Keyword(s):  
Ground Motion ◽  
Response Spectra ◽  
Earthquake Ground Motion ◽  
Improved Method ◽  
Matching Response

Significance of Ground Motion Scaling Parameters on Amplitude of Scale Factors and Seismic Response of Short- and Long-Period Structures

2019 ◽  
Vol 35 (4) ◽  
pp. 1663-1688 ◽  
Author(s):  
Esengul Cavdar ◽  
Gokhan Ozdemir ◽  
Beyhan Bayhan
Keyword(s):  
Seismic Response ◽  
Ground Motion ◽  
Ground Motions ◽  
Response Spectra ◽  
Scaling Method ◽  
Period Range ◽  
Long Period ◽  
Scale Factors ◽  
Short Period ◽  
Response History Analysis

In this study, an ensemble of ground motions is selected and scaled in order to perform code-compliant bidirectional Nonlinear Response History Analysis for the design purpose of both short- and long-period structures. The followed scaling method provides both the requirements of the Turkish Earthquake Code regarding the scaling of ground motions and compatibility of response spectra of selected ground motion pairs with the target spectrum. The effects of four parameters, involved in the followed scaling method, on both the amplitude of scale factors and seismic response of structures are investigated. These parameters are the number of ground motion records, period range, number of periods used in the related period range, and distribution of weight factors at the selected periods. In the analyses, ground motion excitations were applied to both fixed-base and seismically isolated structure models representative of short- and long-period structures, respectively. Results revealed that both the amplitudes of scale factors and seismic response of short-period structures are more prone to variation of investigated parameters compared to those of long-period structures.

Exploration of Deep S-Wave Velocity Structure in Niigata and Shonai Plains to Estimate Long-period Earthquake Ground Motion

2009 ◽  
Vol 61 (4) ◽  
pp. 191-205
Author(s):  
Hiroaki SATO ◽  
Hiroaki YAMANAKA ◽  
Sadanori HIGASHI ◽  
Kiyotaka SATO ◽  
Yoshiaki SHIBA ◽  
...  
Keyword(s):  
Ground Motion ◽  
Wave Velocity ◽  
Velocity Structure ◽  
Earthquake Ground Motion ◽  
S Wave ◽  
Long Period

scholarly journals Application of wavelet for seismic wave analysis in Kathmandu Valley after the 2015 Gorkha earthquake, Nepal

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Binod Adhikari ◽  
Subodh Dahal ◽  
Monika Karki ◽  
Roshan Kumar Mishra ◽  
Ranjan Kumar Dahal ◽  
...  
Keyword(s):  
Wavelet Transform ◽  
Random Process ◽  
Ground Motion ◽  
Structural Damage ◽  
Ground Motions ◽  
Vertical Motion ◽  
Earthquake Ground Motion ◽  
Kathmandu Valley ◽  
Time Frequency ◽  
Long Period

AbstractIn this paper, we estimate the seismogenic energy during the Nepal Earthquake (25 April 2015) and studied the ground motion time-frequency characteristics in Kathmandu valley. The idea to analyze time-frequency characteristic of seismogenic energy signal is based on wavelet transform which we employed here. Wavelet transform has been used as a powerful signal analysis tools in various fields like compression, time-frequency analysis, earthquake parameter determination, climate studies, etc. This technique is particularly suitable for non-stationary signal. It is well recognized that the earthquake ground motion is a non-stationary random process. In order to characterize a non-stationary random process, it is required immeasurable samples in the mathematical sense. The wavelet transformation procedures that we follow here helps in random analyses of linear and non-linear structural systems, which are subjected to earthquake ground motion. The manners of seismic ground motion are characterized through wavelet coefficients associated to these signals. Both continuous wavelet transform (CWT) and discrete wavelet transform (DWT) techniques are applied to study ground motion in Kathmandu Valley in horizontal and vertical directions. These techniques help to point out the long-period ground motion with site response. We found that the long-period ground motions have enough power for structural damage. Comparing both the horizontal and the vertical motion, we observed that the most of the high amplitude signals are associated with the vertical motion: the high energy is released in that direction. It is found that the seismic energy is damped soon after the main event; however the period of damping is different. This can be seen on DWT curve where square wavelet coefficient is high at the time of aftershock and the value decrease with time. In other words, it is mostly associated with the arrival of Rayleigh waves. We concluded that long-period ground motions should be studied by earthquake engineers in order to avoid structural damage during the earthquake. Hence, by using wavelet technique we can specify the vulnerability of seismically active region and local topological features out there.

scholarly journals Simulation of long-period ground motion near a large earthquake

1997 ◽  
Vol 87 (1) ◽  
pp. 140-156 ◽  
Author(s):  
Minoru Takeo ◽  
Hiroo Kanamori
Keyword(s):  
Los Angeles ◽  
Ground Motion ◽  
Source Parameters ◽  
Large Earthquake ◽  
Response Spectra ◽  
Model Parameters ◽  
Long Period ◽  
Kanto Earthquake ◽  
Dominant Period ◽  
Long Period Ground Motion

Abstract We estimated the possible range of long-period ground motion for sites located on a soft sedimentary basin in the immediate vicinity of a large earthquake. Since many large cities in the world (e.g., Los Angeles, San Francisco, and Tokyo) where many large structures have been recently constructed are located in this type of environment, a better understanding of long-period ground motion is becoming increasingly important. Our objective is to estimate the possible range of long-period ground motion, rather than ground motion for a specific fault model. We computed ground-motion time series and pseudo-velocity response spectra (PVS) for more than 5,000 models for the 1923 Kanto, Japan, earthquake (MW = 7.9) using 180 slip distributions, eight rupture geometry, and rupture velocities ranging from 1.5 to 3.0 km/sec. Two seismograms recorded in Tokyo during the 1923 Kanto earthquake are used for comparison. The response spectra computed using seismologically reasonable sets of source parameters for the 1923 Kanto earthquake vary by more than an order of magnitude. At periods of 10 to 13 sec, they range from 25 to 170 cm/sec in Tokyo. For some combinations of model parameters, the response spectra exhibit peaks in the range of 10 to 13 sec. Many of the computed response spectra have peaks at periods longer than 10 sec, which is considerably longer than the dominant period (6 to 8 sec) estimated from studies of small earthquakes and microtremor measurements. Thus, the dominant period of the subsurface structure determined locally may not be representative of the dominant period of ground motion from a nearby large earthquake, which is controlled by rupture directivity and source depth. We performed a similar simulation for a hypothetical MW = 7.5 earthquake located beneath the Los Angeles basin. For a site just above the center of the fault, the ground-motion spectral amplitude at a period of 10 sec can vary from 50 to 350 cm/sec. This range, though very large, is what is expected for a seismologically plausible range of source parameters.

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