Updated PGA, PGV, and Spectral Acceleration Attenuation Relations for Iran

2012 ◽  
Vol 28 (1) ◽  
pp. 257-276 ◽  
Author(s):  
Hamid Saffari ◽  
Yasuko Kuwata ◽  
Shiro Takada ◽  
Abbas Mahdavian

We have developed updated attenuation relations for peak ground acceleration (PGA), peak ground velocity (PGV), and acceleration response spectra with 5% damping on the basis of the data (78 earthquakes and 351 records) pertaining to strong ground motion in Iran. Moment magnitude, distance, fault mechanism, site class, and zone were the model parameters considered. A term for the saturation of the acceleration amplitude was also used in the model in order to improve the estimations in near-source regions. A nonlinear regression analysis was performed to obtain the coefficients. A comparison between the data set used in the current study for Iran and two next generation attenuation (NGA) models showed good correlation between our model and the Campbell-Bozorgnia NGA model. The model described is applicable for moment magnitudes from 5.0 to 7.3, distances from 15 to 135 km, and site classes with an average shear-wave velocity at a subsurface depth of 30 m (AVS30) of more than 175 m/s.

2021 ◽  
Vol 14 (3) ◽  
Author(s):  
Ali K. Abdelfattah ◽  
Abdullah Al-amri ◽  
Kamal Abdelrahman ◽  
Muhamed Fnais ◽  
Saleh Qaysi

AbstractIn this study, attenuation relationships are proposed to more accurately predict ground motions in the southernmost part of the Arabian Shield in the Jazan Region of Saudi Arabia. A data set composed of 72 earthquakes, with normal to strike-slip focal mechanisms over a local magnitude range of 2.0–5.1 and a distance range of 5–200 km, was used to investigate the predictive attenuation relationship of the peak ground motion as a function of the hypocentral distance and local magnitude. To obtain the space parameters of the empirical relationships, non-linear regression was performed over a hypocentral distance range of 4–200 km. The means of 638 peak ground acceleration (PGA) and peak ground velocity (PGV) values calculated from the records of the horizontal components were used to derive the predictive relationships of the earthquake ground motions. The relationships accounted for the site-correlation coefficient but not for the earthquake source implications. The derived predictive attenuation relationships for PGV and PGA are$$ {\log}_{10}(PGV)=-1.05+0.65\cdotp {M}_L-0.66\cdotp {\log}_{10}(r)-0.04\cdotp r, $$ log 10 PGV = − 1.05 + 0.65 · M L − 0.66 · log 10 r − 0.04 · r , $$ {\log}_{10}(PGA)=-1.36+0.85\cdotp {M}_L-0.85\cdotp {\log}_{10}(r)-0.005\cdotp r, $$ log 10 PGA = − 1.36 + 0.85 · M L − 0.85 · log 10 r − 0.005 · r , respectively. These new relationships were compared to the grand-motion prediction equation published for western Saudi Arabia and indicate good agreement with the only data set of observed ground motions available for an ML 4.9 earthquake that occurred in 2014 in southwestern Saudi Arabia, implying that the developed relationship can be used to generate earthquake shaking maps within a few minutes of the event based on prior information on magnitudes and hypocentral distances taking into considerations the local site characteristics.


2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Dong-Kwan Kim ◽  
Hong-Gun Park ◽  
Chang-Guk Sun

Site response analyses were performed to investigate the earthquake response of structures with shallow soil depth conditions in Korea. The analysis parameters included the properties of soft soil deposits at 487 sites, input earthquake accelerations, and peak ground-acceleration levels. The response spectra resulting from numerical analyses were compared with the design response spectra (DRS) specified in the 2015 International Building Code. The results showed that the earthquake motion of shallow soft soil was significantly different from that of deep soft soil, which was the basis of the IBC DRS. The responses of the structures were amplified when their dynamic periods were close to those of the site. In the case of sites with dynamic periods less than 0.4 s, the spectral accelerations of short-period structures were greater than those of the DRS corresponding to the site class specified in IBC 2015. On the basis of these results, a new form of DRS and soil factors are proposed.


2008 ◽  
Vol 24 (1) ◽  
pp. 217-242 ◽  
Author(s):  
I. M. Idriss

An empirical model for estimating the horizontal pseudo absolute spectral accelerations (PSA) generated by shallow crustal earthquakes is presented in this paper. The model was selected to be simple and the model parameters were estimated using the recordings gathered as part of the New Generation Attenuation (NGA) project. These parameters are presented for sites with an average shear wave velocity in the upper 30 m, VS30>900 m/s, and for sites with 450 m/s≤ VS30≤900 m/s. Site-specific dynamic response calculations are recommended for estimating spectral ordinates for sites with VS30≤180 m/s. Parameters for sites with 180 m/s< VS30<450 m/s are not included in this paper. The median values of peak horizontal ground acceleration (PGA) and PSA for short periods are on the order of 15% to 20% lower for strike slip events and 30% to 40% lower for reverse events than those calculated using pre-NGA relationships. The differences decrease significantly at longer periods. The minimum values of the standard error terms (for moment magnitude, M≥7.5) are about 15% to 30% larger and the maximum values of the standard error terms (for M≤5) are about 2% to 12% larger than the pre-NGA values.


2016 ◽  
Vol 32 (4) ◽  
pp. 2549-2566 ◽  
Author(s):  
Nicolas Bastías ◽  
Gonzalo A. Montalva

The Nazca-South American plate boundary produces large-magnitude events (Mw > 8) every 20 years on the coast of Chile. This work describes a public ground motion database that contains 3,572 records from 477 earthquakes and 181 seismic stations, which includes the recent 2015 Mw 8.3 Illapel earthquake. The data set is controlled by subduction interface and inslab events. The oldest event included is Valparaiso (1985), and the magnitude span is 4.6–8.8 Mw. The source-to-site distance metrics reported are the closest distance to the rupture plane ( R rup), epicentral ( R epi) and hypocentral ( R hyp) distances, with a range for R rup from 20 to 650 km. Site characterization is based on V S30, ranging from 110 to 1,951 m/s. Intensity measures included are peak ground acceleration, spectral acceleration values from 0.01 to 10 s, Arias intensity, and peak ground velocity. Each record was uniformly processed component by component. A flatfile with the related metadata and the spectral accelerations from processed ground motions is available at NEEShub ( http://doi.org/10.17603/DS2N30J ; Bastías and Montalva 2015 ).


Author(s):  
J. J. Hu ◽  
H. Zhang ◽  
J. B. Zhu ◽  
G. H. Liu

AbstractA moderate magnitude earthquake with Mw 5.8 occurred on June 17, 2019, in Changning County, Sichuan Province, China, causing 13 deaths, 226 injuries, and serious engineering damage. This earthquake induced heavier damage than earthquakes of similar magnitude. To explain this phenomenon in terms of ground motion characteristics, based on 58 sets of strong ground motions in this earthquake, the peak ground acceleration (PGA), peak ground velocity (PGV), acceleration response spectra (Sa), duration, and Arias intensity are analyzed. The results show that the PGA, PGV, and Sa are larger than the predicted values from some global ground motion models. The between-event residuals reveal that the source effects on the intermediate-period and long-period ground motions are stronger than those on short-period ground motions. Comparison of Arias intensity attenuation with the global models indicates that the energy of ground motions of the Changning earthquake is larger than those of earthquakes with the same magnitude.


1995 ◽  
Vol 85 (5) ◽  
pp. 1343-1358
Author(s):  
Gilbert L. Molas ◽  
Fumio Yamazaki

Abstract New attenuation equations for peak ground acceleration and velocity for Japan are developed. The equations are derived using extensive data recorded by the new JMA-87-type accelerometers, which do not require instrumental corrections that the older SMAC-type accelerometers do. Earthquakes with depths up to 200 km are used to make the equation applicable to subduction zone regions, which are common in Japan. Effects of depth and local site on the attenuation are considered simultaneously with the distance dependence and magnitude dependence using a two-stage regression procedure to separate the magnitude dependence from the distance dependence. Since the resulting normal equations become singular, an iterative partial regression algorithm is proposed. It is found that for the same magnitude and distance, peak ground motion increases as depth increases. The variation of the station coefficients with respect to the corresponding soil-type classification is quite wide. The station coefficients for the peak ground acceleration are found to be weakly correlated with the general soil classification, while a stronger correlation was found for the peak ground velocity. The resulting attenuation relations are given by log10PGA=0.206+0.477MJ−log10r−0.00144r−0.00144r+0.00311h+cia,log10PGV=−1.769+0.628MJ−log10r−0.00130r−0.00144r+0.00222h+civ, where PGA (cm/sec2) and PGV (cm/sec) are the larger of the peak accelerations and velocities from two horizontal components, MJ is the JMA magnitude, r is the closest distance to the fault rupture, h is the depth, and ci is the station coefficient of the recording station. The mean of the coefficients of the JMA stations is given by ci = 0.


2019 ◽  
Vol 1 (1) ◽  
pp. 20-26
Author(s):  
Bambang Sunardi ◽  
Sulastri ◽  
Dwikorita Karnawati ◽  
Urip Haryoko ◽  
Supriyanto Rohadi ◽  
...  

A 7.4 magnitude earthquake have strucked Donggala on September 28th 2018, followed by tsunami and liquefaction which hit Palu, Central Sulawesi, a few minutes later. This event had resulted in damage to buildings, and caused more than 2,000 people were killed and injured. Indonesia already have a building code in form of SNI 1726:2002 which had been updated to SNI 1726:2012. This paper analyses the hazard level caused by the 2018 Donggala earthquake compared to the existing design spectra, as mentioned in SNI 1726:2002 and SNI 1726:2012. A simple analysis was carried out by comparing Donggala earthquake’s acceleration response spectra with the existing design spectra, at the MPSI accelerograph station. The site class at MPSI station is hard soil (SC). The seismic hazard in Palu and Donggala refers to SNI 1726:2002 is included in the earthquake area 4. The maximum earthquake response factor for earthquake area 4 is about 0.6 for hard soil type (SC). The MPSI station recorded peak ground acceleration of Donggala earthquake around 0.14 g. The acceleration response spectra recorded at the MPSI station showed a peak value of around 0.71 g for the N component. This value is actually still below the design spectra referring to SNI 1726:2012, which the peak value is 0.88 g for SC, but, it exceeded the design spectra of SNI 1726:2002.


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