Seismic Intensity and Fourier Acceleration Spectra: Revised Relationship

2002 ◽  
Vol 18 (1) ◽  
pp. 161-187 ◽  
Author(s):  
Vladimir Yu Sokolov
Keyword(s):  
Ground Motion ◽  
Seismic Intensity ◽  
Intensity Level ◽  
Ground Acceleration ◽  
Soil Response ◽  
Local Soil ◽  
Spectral Models ◽  
Source Scaling ◽  
Instrumental Intensity ◽  
Comparison Of The Results

This paper presents a revised method for estimating the seismic intensity (MMI or MSK scale) using Fourier amplitude spectra (FAS) of ground acceleration. The improvement of the recently proposed technique (Sokolov and Chernov 1998) has been made on the basis of the data, which were obtained recently during strong earthquakes that occurred throughout the world. The total amount of the used data (horizontal components of ground-motion recordings) is about 1,150 records, while the database of 300 recordings was used in the previous study. The method implies that the seismic intensity is determined by the level of ground motion spectral amplitudes in the frequency range of 0.4–13 Hz. The corresponding empirical relationships between FAS and each intensity level were developed. The method is validated by comparison of the results of the technique application with the empirical data, which have not been included in the database. The Romanian earthquakes (intermediate-depth events of 1977, 1986, and 1990) and the recent 1999 Hector Mine earthquake in southern California were used for this purpose. In general, the FAS intensity shows a good agreement with the reported intensity, and the average residuals do not exceed ±0.3 intensity units and standard deviation is about 0.4-0.6. Evaluation of seismic intensity distribution using region- and site-dependent spectral models, as well as calculation of instrumental intensity map for the recent 1999 Chi-Chi earthquake, Taiwan, show that the FAS intensity clearly reflects the regional (source scaling and attenuation relation) and local (soil response) peculiarities of ground motion.

scholarly journals Investigating the influence of topographic irregularities and two-dimensional effects on surface ground motion intensity with one- and two-dimensional analyses

2014 ◽  
Vol 14 (7) ◽  
pp. 1773-1788 ◽  
Author(s):  
G. Ç. İnce ◽  
L. Yılmazoğlu
Keyword(s):  
Ground Motion ◽  
Site Response ◽  
Soil Conditions ◽  
Response Analysis ◽  
Two Dimensional ◽  
Ground Acceleration ◽  
Equivalent Linear ◽  
Local Soil ◽  
Different Depths ◽  
Earthquake Response Analysis

Abstract. In this work, the surface ground motion that occurs during an earthquake in ground sections having different topographic forms has been examined with one and two dynamic site response analyses. One-dimensional analyses were undertaken using the Equivalent-Linear Earthquake Response Analysis (EERA) program based on the equivalent linear analysis principle and the Deepsoil program which is able to make both equivalent linear and nonlinear analyses and two-dimensional analyses using the Plaxis 8.2 software. The viscous damping parameters used in the dynamic site response analyses undertaken with the Plaxis 8.2 software were obtained using the DeepSoil program. In the dynamic site response analyses, the synthetic acceleration over a 475-year return period representing the earthquakes in Istanbul was used as the basis of the bedrock ground motion. The peak ground acceleration obtained different depths of soils and acceleration spectrum values have been compared. The surface topography and layer boundaries in the 5-5' cross section which cuts across the study area west to east were selected in order to examine the effect of the land topography and layer boundaries on the analysis results, and were flattened and compared with the actual status. The analysis results showed that the characteristics of the surface ground motion change in relation to the varying local soil conditions and land topography.

SEISMIC COLLAPSING ANALYSIS OF ONE-STORY WOODEN KINDERGARTEN STRUCTURE AGAINST STRONG EARTHQUAKE GROUND MOTION

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Tomiya Takatani ◽  
Hayato Nishikawa
Keyword(s):  
Ground Motion ◽  
Strong Earthquake ◽  
Process Analysis ◽  
Ground Motions ◽  
Seismic Intensity ◽  
Earthquake Ground Motion ◽  
Intensity Level ◽  
Wooden Structure ◽  
Old Japanese ◽  
Upper Level

3-D collapsing process analysis of an old Japanese-style one-story wooden structure under two strong earthquake ground motions with a seismic intensity level was car-ried out in order to investigate the seismic performance of this one-story wooden structure without/with seismic retrofit. As a result, this wooden structure collapsed against a strong earthquake ground motion with the JMA seismic intensity “6 upper” level.

scholarly journals New Ground Motion to Intensity Conversion Equations for China

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Xiufeng Tian ◽  
Zengping Wen ◽  
Weidong Zhang ◽  
Jie Yuan
Keyword(s):  
Ground Motion ◽  
Correction Term ◽  
Strong Motion ◽  
Seismic Intensity ◽  
Peak Ground Velocity ◽  
Ground Acceleration ◽  
Strong Earthquakes ◽  
Hypocentral Distance ◽  
Peak Ground Motion ◽  
Pseudo Spectral

In this study, we use the strong motion records and seismic intensity data from 11 moderate-to-strong earthquakes in the mainland of China since 2008 to develop new conversion equations between seismic intensity and peak ground motion parameters. Based on the analysis of the distribution of the dataset, the reversible conversion relationships between modified Mercalli intensity (MMI) and peak ground acceleration (PGA), peak ground velocity (PGV), and pseudo-spectral acceleration (PSA) at natural vibration periods of 0.3 s, 1.0 s, 2.0 s, and 3.0 s are obtained by using the orthogonal regression. The influence of moment magnitude, hypocentral distance, and hypocentral depth on the residuals of conversion equations is also explored. To account for and eliminate the trends in the residuals, we introduce a magnitude-distance-depth correction term and obtain the improved relationships. Furthermore, we compare the results of this study with previously published works and analyze the regional dependence of conversion equations. To quantify the regional variations, a regional correction factor for China, suitable for adjustment of global relationships, has also been estimated.

A New Method for the Realistic Estimation of Seismic Ground Motion in Megacities: The Case of Rome

1993 ◽  
Vol 9 (4) ◽  
pp. 643-668 ◽  
Author(s):  
Donat Fäh ◽  
Claudio Iodice ◽  
Peter Suhadolc ◽  
Guilano F. Panza
Keyword(s):  
Total Energy ◽  
Ground Motion ◽  
Sedimentary Basins ◽  
Radial Component ◽  
Hybrid Technique ◽  
Ground Acceleration ◽  
Near Surface ◽  
Local Soil ◽  
Soil Effects ◽  
Rigid Material

A hybrid technique, based on mode summation and finite differences, is used to simulate the ground motion induced in the city of Rome by the January 13, 1915, Fucino (Italy) earthquake (ML=6.8). The technique allows us to take into consideration source, path, and local soil effects. The results of the numerical simulations are used for a comparison between the observed distribution of damage in Rome, and the computed peak ground acceleration, the maximum response of simple oscillators, and the so-called “total energy of ground motion”. The total energy of ground motion is in good agreement with the observed distribution of damage. From the computation of spectral ratios, it has been recognized that the presence of a near-surface layer of rigid material is not sufficient to classify a location as a “hard-rock site” when the rigid material has a sedimentary complex below it. This is because the underlying sedimentary complex causes amplifications due to resonances. Within sedimentary basins, incident energy in certain frequency bands can also be shifted from the vertical, into the radial component of motion. This phenomenon is very localized, both in frequency and space, and closely neighboring sites can be characterized by large differences in the seismic response.

On the Correlation of Seismic Intensity with Fourier Amplitude Spectra

1998 ◽  
Vol 14 (4) ◽  
pp. 679-694 ◽  
Author(s):  
V. Yu Sokolov ◽  
Yu K. Chernov
Keyword(s):  
Seismic Waves ◽  
Distribution Patterns ◽  
Seismic Intensity ◽  
Earthquake Ground Motion ◽  
Intensity Level ◽  
Fourier Amplitude ◽  
Ground Acceleration ◽  
Amplitude Spectra ◽  
Narrow Frequency Band ◽  
Recent Earthquakes

This paper presents a method for estimating the seismic intensity (MMI or MSK scale) using Fourier amplitude spectra of ground acceleration. The method implies that the severity of earthquake ground motion is determined by spectral amplitudes in a relatively narrow frequency band: so-called “representative frequencies”, at decreasing frequencies (from 7-8 Hz for small intensities to 0.7-1.0 Hz for MMI=VIII-IX) with increasing intensity level. It is examined through estimation of probable intensity at a site using recordings of recent earthquakes in several seismic regions, and prediction of intensity distribution patterns for the Coalinga, California earthquake of May 2, 1983, and the Spitak, Armenia earthquake of December 7, 1988. Seismic hazard maps, in terms of intensity levels based upon the proposed approach, should describe regional features of seismic waves excitation and propagation, as well as local ground conditions.

scholarly journals Equivalent-linear seismic ground response analysis in Palu area

2021 ◽  
Vol 930 (1) ◽  
pp. 012089
Author(s):  
A Jalil ◽  
T F Fathani ◽  
I Satyarno ◽  
W Wilopo
Keyword(s):  
Response Spectrum ◽  
Soil Layer ◽  
Time History ◽  
Surface Damage ◽  
Response Analysis ◽  
Infrastructure Development ◽  
Ground Response Analysis ◽  
Ground Acceleration ◽  
Soil Response ◽  
Local Soil

Abstract The 7.5 Mw Palu earthquake on September 28, 2018, was caused by the Palu Koro fault. This earthquake produced forceful wave propagation in the soil layer and generated enormous surface damage in Balaroa, Petobo, and Jono Oge. Estimations of soil amplification at a specific location are helpful as guidance for infrastructure development. This study examined the effect of local soil in modifying the one-dimensional linear soil response in Balaroa, Petobo, and Jono Oge regions, considering the data of various sites in those regions. The soil response was observed to obtain the synthetic input motion and its effects in the time history of surface acceleration, the ratio of shear stress to effective vertical stress to spectrum response time, and the Fourier amplitude versus frequency ratio. Amplification is standard for ground acceleration, which considers the strong ground motion with the acquired frequency and duration of the content. The results showed that the peak of ground acceleration amplification factors for Balaroa, Petobo, and Jono Oge was around 1.49, 2.05, and 1.27 times, respectively. With a lack of information at the particular site, designers will use the response spectrum obtained along the soil layer to develop earthquake-resistant geotechnical structures in locations close to Palu.

scholarly journals Source Model and Simulated Strong Ground Motion of the 2021 Yangbi, China Shallow Earthquake Constrained by InSAR Observations

2021 ◽  
Vol 13 (20) ◽  
pp. 4138
Author(s):  
Yongzhe Wang ◽  
Kun Chen ◽  
Ying Shi ◽  
Xu Zhang ◽  
Shi Chen ◽  
...  
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Surface Deformation ◽  
Source Model ◽  
Seismic Intensity ◽  
Deformation Pattern ◽  
Source Modeling ◽  
Ground Acceleration ◽  
Strong Ground Motion Simulation ◽  
Strong Ground

On 21 May 2021, an Mw 6.1 earthquake, causing considerable seismic damage, occurred in Yangbi County, Yunnan Province of China. To better understand the surface deformation pattern, source characteristics, seismic effect on nearby faults, and strong ground motion, we processed the ascending and descending SAR images using the interferometric synthetic aperture radar (InSAR) technique to capture the radar line-of-sight (LOS) directional and 2.5-dimensional deformation. The source model was inverted from the LOS deformation observations. We further analyzed the Coulomb failure stress (CFS) transfer and peak ground acceleration (PGA) simulation based on the preferred source model. The results suggest that the 2021 Yangbi earthquake was dextral faulting with the maximum slip of 0.9 m on an unknown blind shallow fault, and the total geodetic moment was 1.4 × 1018 Nm (Mw 6.06). Comprehensive analysis of the CFS transfer and geological tectonics suggests that the Dian–Xibei pull-apart basin is still suffering high seismic hazards. The PGA result demonstrates that the seismic intensity of this event reached up to VIII. The entire process from InSAR deformation to source modeling and strong ground motion simulation suggests that the InSAR technique will play an important role in the assessment of earthquake disasters in the case of the shortening of the SAR imaging interval.

Study on Instrumental Intensity Using Wenchuan Earthquake Records

2012 ◽  
Vol 226-228 ◽  
pp. 2235-2239
Author(s):  
Ming Zhang ◽  
Yu Zhang ◽  
Guang Chun Zhou
Keyword(s):  
Wenchuan Earthquake ◽  
Peak Ground Acceleration ◽  
Seismic Intensity ◽  
Peak Ground Velocity ◽  
Regression Equations ◽  
Ground Acceleration ◽  
Earthquake Records ◽  
The Wenchuan Earthquake ◽  
Instrumental Intensity ◽  
Seismic Intensity Scale

This paper invesigates the peak ground acceleration (PGA) and peak ground velocity (PGV) regression equations as well as the PGA or PGV middle values in Chinese seismic intensity scale 2008 (the CSIS 2008), using the Wenchuan earthquake records of China with the full seismic information. Based on the analytical results, the PGA-V method is proposed to assess the instrumental intensity which combines both PGA and PGV. Besides, a problem is raised to further verify and modify the middle values of PGA or PGV for the seismic intensity VI and VII in the CSIS 2008.

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