scholarly journals Estimation of Peak Ground Acceleration (PGA) and Spectral Acceleration (Sa) Vertical Component for Interface Subduction Zone Earthquakes of North-east India (NEI) and Adjacent Regions

Author(s):  
Rahman Tauhidur ◽  
Ricky L Chhangte

Abstract This article presented ground motion model (GMM) for vertical peak ground acceleration (PGA) and pseudo spectral acceleration (Sa) at 5 % damping for North-east India (NEI) and adjacent regions at a time period of 0.01 to 5 s, and hypocentral distance 40 to 300 km. We used combined point source (4.5 ≤ Mw ≤ 6.5) and finite fault model (6.5 < Mw ≤ 9.5) (refer as combined model) to develop GMM for vertical component of ground motion (VCGM) for the region. The vertical GMM obtained is validated with the available recorded events in NEI and adjacent regions for the interface subduction zone earthquakes. It is observed that peak ground accelerations and spectral accelerations are 55 to 65% lesser than the horizontal components of ground motions. VCGM parameters obtained in this study play an important role in designing low rise buildings and linear superstructures such as bridges, silos and chimneys.

2003 ◽  
Vol 19 (3) ◽  
pp. 511-529 ◽  
Author(s):  
John E. Ebel ◽  
David J. Wald

We describe a new probabilistic method that uses observations of modified Mercalli intensity (MMI) from past earthquakes to make quantitative estimates of ground shaking parameters (i.e., peak ground acceleration, peak ground velocity, 5% damped spectral acceleration values, etc.). The method uses a Bayesian approach to make quantitative estimates of the probabilities of different levels of ground motions from intensity data given an earthquake of known location and magnitude. The method utilizes probability distributions from an intensity/ground motion data set along with a ground motion attenuation relation to estimate the ground motion from intensity. The ground motions with the highest probabilities are the ones most likely experienced at the site of the MMI observation. We test the method using MMI/ground motion data from California and published ground motion attenuation relations to estimate the ground motions for several earthquakes: 1999 Hector Mine, California (M7.1); 1988 Saguenay, Quebec (M5.9); and 1982 Gaza, New Hampshire (M4.4). In an example where the method is applied to a historic earthquake, we estimate that the peak ground accelerations associated with the 1727 (M∼5.2) earthquake at Newbury, Massachusetts, ranged from 0.23 g at Newbury to 0.06 g at Boston.


2021 ◽  
pp. 875529302110438
Author(s):  
Chenying Liu ◽  
Jorge Macedo

The PEER NGA-Sub ground-motion intensity measure database is used to develop new conditional ground-motion models (CGMMs), a set of scenario-based models, and non-conditional models to estimate the cumulative absolute velocity ([Formula: see text]) of ground motions from subduction zone earthquakes. In the CGMMs, the median estimate of [Formula: see text] is conditioned on the estimated peak ground acceleration ([Formula: see text]), the time-averaged shear-wave velocity in the top 30 m of the soil ([Formula: see text]), the earthquake magnitude ([Formula: see text]), and the spectral acceleration at the period of 1 s ([Formula: see text]). Multiple scenario-based [Formula: see text] models are developed by combining the CGMMs with pseudo-spectral acceleration ([Formula: see text]) ground-motion models (GMMs) for [Formula: see text] and [Formula: see text] to directly estimate [Formula: see text] given an earthquake scenario and site conditions. Scenario-based [Formula: see text] models are capable of capturing the complex ground-motion effects (e.g. soil non-linearity and regionalization effects) included in their underlying [Formula: see text]/[Formula: see text] GMMs. This approach also ensures the consistency of the [Formula: see text] estimates with a [Formula: see text] design spectrum. In addition, two non-conditional [Formula: see text] GMMs are developed using Bayesian hierarchical regressions. Finally, we present comparisons between the developed models. The comparisons show that if non-conditional GMMs are properly constrained, they are consistent with scenario-based GMMs. The [Formula: see text] GMMs developed in this study advance the performance-based earthquake engineering practice in areas affected by subduction zone earthquakes.


1969 ◽  
Vol 59 (4) ◽  
pp. 1719-1731
Author(s):  
Jai Krishna ◽  
A. R. Chandrasekaran ◽  
S. S. Saini

Abstract This accelerogram is so far the strongest recorded near an epicenter of a shock with a peak-ground acceleration of 63 per cent of gravity. Displacement and velocity spectra as well as ground displacements and velocities have been obtained. Spectral intensities of this shock indicate that the vertical component of ground motion is as intense as the horizontal components supporting such general conjectures of motion near an epicenter.


1994 ◽  
Vol 10 (2) ◽  
pp. 259-292 ◽  
Author(s):  
W. P. Aspinall ◽  
J. B. Shepherd ◽  
G. Woo ◽  
A. Wightman ◽  
K. C. Rowley ◽  
...  

The seismic hazard at the site of a new dam in Saint Lucia, West Indies, is evaluated probabilistically for engineering design purposes. The assessment takes advantage of recent high quality regional seismological data, reappraised older instrumental catalogues and current tectonic interpretations. Saint Lucia stands at a position in the Lesser Antilles island arc where two distinct, seismically active, subduction zones appear to converge at different depths. As a result, the seismic hazard is critically dependent on site position relative to the boundaries of these major source zones, which each exhibit different activity rates. The ground motion hazard at the damsite is computed using the probabilistic logic-tree program PRISK, which accepts weighted input parameter distributions and is also able to model complex source geometries such as those needed to realistically represent a subduction zone. At an exceedance probability of 2×10−3 per annum, the expected peak ground acceleration on rock at the site is 0.27g, and the expected peak ground velocity is 12.9 cm/sec. At an exceedance probability of 10−4 per annum, the expected peak ground acceleration on rock at the site is 0.51g, and the expected peak ground velocity is 29.1 cm/sec. The major contributor to the seismic hazard is a large magnitude earthquake occurring in the northern segment of the Lesser Antilles subduction zone. Sensitivity tests show that the results are stable in the face of rational variations in the seismicity parameters but the hazard values are dependent on the choice of attenuation relationship which, in the absence of local information, has to be adopted from other subduction zone areas. The PGA obtained in this study is markedly higher than the value suggested in current regional code recommendations.


IEEE Access ◽  
2017 ◽  
Vol 5 ◽  
pp. 23920-23937
Author(s):  
M. S. Liew ◽  
Kamaluddeen Usman Danyaro ◽  
Mazlina Mohamad ◽  
Lim Eu Shawn ◽  
Aziz Aulov

2015 ◽  
Vol 31 (3) ◽  
pp. 1629-1645 ◽  
Author(s):  
Ronnie Kamai ◽  
Norman Abrahamson

We evaluate how much of the fling effect is removed from the NGA database and accompanying GMPEs due to standard strong motion processing. The analysis uses a large set of finite-fault simulations, processed with four different high-pass filter corners, representing the distribution within the PEER ground motion database. The effects of processing on the average horizontal component, the vertical component, and peak ground motion values are evaluated by taking the ratio between unprocessed and processed values. The results show that PGA, PGV, and other spectral values are not significantly affected by processing, partly thanks to the maximum period constraint used when developing the NGA GMPEs, but that the bias in peak ground displacement should not be ignored.


An effective earthquake (Mw 7.9) struck Alaska on 3 November, 2002. This earthquake ruptured 340 km along Susitna Glacier, Denali and Totschunda faults in central Alaska. The peak ground acceleration (PGA) was recorded about 0.32 g at station PS10, which was located 3 km from the fault rupture. The PGA would have recorded a high value, if more instruments had been installed in the region. A numerical study has been conducted to find out the possible ground motion record that could occur at maximum horizontal slip during the Denali earthquake. The current study overcomes the limitation of number of elements to model the Denali fault. These numerical results are compared with observed ground motions. It is observed that the ground motions obtained through numerical analysis are in good agreement with observed ground motions. From numerical results, it is observed that the possible expected PGA is 0.62 g at maximum horizontal slip of Denali fault.


2009 ◽  
Vol 9 (3) ◽  
pp. 865-878 ◽  
Author(s):  
K. S. Vipin ◽  
P. Anbazhagan ◽  
T. G. Sitharam

Abstract. In this work an attempt has been made to evaluate the seismic hazard of South India (8.0° N–20° N; 72° E–88° E) based on the probabilistic seismic hazard analysis (PSHA). The earthquake data obtained from different sources were declustered to remove the dependent events. A total of 598 earthquakes of moment magnitude 4 and above were obtained from the study area after declustering, and were considered for further hazard analysis. The seismotectonic map of the study area was prepared by considering the faults, lineaments and the shear zones in the study area which are associated with earthquakes of magnitude 4 and above. For assessing the seismic hazard, the study area was divided into small grids of size 0.1°×0.1°, and the hazard parameters were calculated at the centre of each of these grid cells by considering all the seismic sources with in a radius of 300 km. Rock level peak horizontal acceleration (PHA) and spectral acceleration (SA) values at 1 s corresponding to 10% and 2% probability of exceedance in 50 years have been calculated for all the grid points. The contour maps showing the spatial variation of these values are presented here. Uniform hazard response spectrum (UHRS) at rock level for 5% damping and 10% and 2% probability of exceedance in 50 years were also developed for all the grid points. The peak ground acceleration (PGA) at surface level was calculated for the entire South India for four different site classes. These values can be used to find the PGA values at any site in South India based on site class at that location. Thus, this method can be viewed as a simplified method to evaluate the PGA values at any site in the study area.


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