A Probabilistic Seismic Hazard Analysis of Northeast India

2006 ◽  
Vol 22 (1) ◽  
pp. 1-27 ◽  
Author(s):  
Sandip Das ◽  
Ishwer D. Gupta ◽  
Vinay K. Gupta
Keyword(s):  
Seismic Hazard ◽  
Hazard Analysis ◽  
Response Spectra ◽  
Northeast India ◽  
Entire Area ◽  
The Past ◽  
Hazard Response ◽  
Hazard Level ◽  
Spectral Velocity ◽  
Pseudo Spectral

Seismic hazard maps have been prepared for Northeast India based on the uniform hazard response spectra for absolute acceleration at stiff sites. An approach that is free from regionalizing the seismotectonic sources has been proposed for performing the hazard analysis. Also, a new attenuation model for pseudo-spectral velocity scaling has been developed by using 261 recorded accelerograms in Northeast India. In the present study, the entire area of Northeast India has been divided into 0.1° grid size, and the hazard level has been assessed for each node of this grid by considering the seismicity within a 300-km radius around the node. Using the past earthquake data, the seismicity for the area around each node has been evaluated by defining a and b values of the Gutenberg-Richter recurrence relationship, while accounting for the incompleteness of the earthquake catalogue. To consider the spatial distribution of seismicity around each node, a spatially smoothed probability distribution function of the observed epicentral distances has been used. Uniform hazard contours for pseudo-spectral acceleration as the hazard parameter have been obtained for an exposure time of 100 years and for 50% confidence level at different natural periods for both horizontal and vertical components of ground motion. The trends reflected by these contours are broadly consistent with the major seismotectonic features in the region.

Seismic Hazard Analysis for an NPP Site

2004 ◽  
Author(s):  
A. K. Ghosh ◽  
H. S. Kushwaha
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Peak Ground Acceleration ◽  
Hazard Analysis ◽  
Structural Response ◽  
Response Spectra ◽  
Seismic Fragility ◽  
Material Strength ◽  
Ground Acceleration ◽  
Hazard Response

The various uncertainties and randomness associated with the occurrence of earthquakes and the consequences of their effects on the NPP components and structures call for a probabilistic seismic risk assessment (PSRA). However, traditionally, the seismic design basis ground motion has been specified by normalised response spectral shapes and peak ground acceleration (PGA). The mean recurrence interval (MRI) used to be computed for PGA only. The present work develops uniform hazard response spectra i.e. spectra having the same MRI at all frequencies for Kakrapar Atomic Power Station site. Sensitivity of the results to the changes in various parameters has also been presented. These results determine the seismic hazard at the given site and the associated uncertainties. The paper also presents some results of the seismic fragility for an existing containment structure. The various parameters that could affect the seismic structural response include material strength of concrete, structural damping available within the structure and the normalized ground motion response spectral shape. Based on this limited case study the seismic fragility of the structure is developed. The results are presented as families of conditional probability curves plotted against the peak ground acceleration (PGA). The procedure adopted incorporates the various randomness and uncertainty associated with the parameters under consideration.

scholarly journals Probabilistic seismic hazard analysis using the logic tree approach – Patna district (India)

2019 ◽  
Vol 19 (10) ◽  
pp. 2097-2115 ◽  
Author(s):  
Panjamani Anbazhagan ◽  
Ketan Bajaj ◽  
Karanpreet Matharu ◽  
Sayed S. R. Moustafa ◽  
Nassir S. N. Al-Arifi
Keyword(s):  
Epistemic Uncertainty ◽  
Hazard Analysis ◽  
Response Spectra ◽  
Maximum Magnitude ◽  
Logic Tree ◽  
Ground Acceleration ◽  
Incremental Method ◽  
Seismicity Parameters ◽  
Hazard Response ◽  
Tree Approach

Abstract. Peak ground acceleration (PGA) and study area (SA) distribution for the Patna district are presented considering both the classical and zoneless approaches through a logic tree framework to capture the epistemic uncertainty. Seismicity parameters are calculated by considering completed and mixed earthquake data. Maximum magnitude is calculated using three methods, namely the incremental method, Kijko method, and regional rupture characteristics approach. The best suitable ground motion prediction equations (GMPEs) are selected by carrying out an “efficacy test” using log likelihood. Uniform hazard response spectra have been compared with Indian standard BIS 1893. PGA varies from 0.38 to 0.30 g from the southern to northern periphery considering 2 % probability of exceedance in 50 years.

scholarly journals Probabilistic seismic hazard analysis using logic tree approach – Patna District (India)

2019 ◽  
Author(s):  
Panjamani Anbazhagan ◽  
Ketan Bajaj ◽  
Karanpreet Matharu ◽  
Sayed S. R. Moustafa ◽  
Nassir S. N. Al-Arifi
Keyword(s):  
Epistemic Uncertainty ◽  
Hazard Analysis ◽  
Response Spectra ◽  
Maximum Magnitude ◽  
Logic Tree ◽  
Incremental Method ◽  
Seismicity Parameters ◽  
Hazard Response ◽  
Frame Work ◽  
Tree Approach

Abstract. PGA and SA distribution for Patna district is presented considering both classical and zoneless approach through logic tree frame work to capture the epistemic uncertainty. Seismicity parameters are calculated by considering completed and mixed earthquake data. Maximum magnitude was calculated using three methods namely incremental method, Kijko method and regional rupture characteristics approach. Best suitable GMPE was selected by carrying out efficacy test using log likelihood. Uniform hazard response spectra have been compared with Indian standard BIS 1893. PGA varies from 0.38 g to 0.30 g from southern to northern periphery considering 2 % probability of exceedence in 50 years.

scholarly journals Determination of Local Site-Specific Spectra Using Probabilistic Seismic Hazard Analysis for Bitlis Province, Turkey

2015 ◽  
Vol 19 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Ercan Işık ◽  
Mustafa Kutanis
Keyword(s):  
Seismic Hazard ◽  
Hazard Analysis ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Response Spectra ◽  
Probabilistic Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard ◽  
Source Characterization ◽  
Site Specific ◽  
Attenuation Relationships

<p>In this study, site-specific earthquake spectra for Bitlis province in Lake Van Basin has been obtained. It is noteworthy that, in probabilistic seismic hazard assessment, as a first stage data from geological studies and records from the instrumental period were compiled to make a seismic source characterization for the study region.The probabilistic seismic hazard curves for Bitlis were developed based on selected appropriate attenuation relationships, at rock sites, with a probability of exceedance 2%, 10% and 50% in 50 year periods. The obtained results were compared with the spectral responses proposed for seismic evaluation and retrofit of the building structure in Turkish Earthquake Code, Section 2. At the end of this study, it is apprehended that the Code proposed earthquake response spectra are not sufficient for the performance evaluation of the existing structures and the current estimations show that the potential seismic hazard research of the Turkey is underestimated in the code.Therefore, site- specific design spectra for the region should be developed, which reflect the characteristics of local sites.</p><p> </p><p><strong>Determinación de espectros de sitio específico locales a través del análisis probabilístico de amenazas sísmicaspara la provincia de Bitlis, Turquía</strong></p><p> </p><p><strong>Resumen</strong></p>En este estudio se obtuvieron espectros de terremoto de sitio específico para la cuenca del Lago de Van, en la provincia de Bitlis, al este de Turquía. La primera fase del trabajo consistió en una evaluación probabilística de riesgo sísmico donde se compilaron los estudios geológicos y registros del período instrumental para hacer una caracterización de fuente sísmica en la región de estudio. Las curvas de amenaza sísmica para la provincia de Bitlis se desarrollaron con base en las relaciones de atenuación apropiada seleccionadas en los sitios rocosos, con una probabilidad de exceso de 2 %, 10 % y 50 % durante 50 años. Los resultados obtenidos se compararon con las respuestas de espectro propuestas para la evaluación sísmica y modernización de estructuras contempladas en el Código de Terremoto de Turquía, en la sección 2. En la parte final de este trabajo se comprende que las respuestas de espectros de terremoto propuestos en el código no son suficientes para la evaluación de desempeño de las estructuras existentes y que las estimaciones actuales muestran que la investigación de amenazas potenciales sísmicas en Turquía está subestimada en el código. Por lo tanto, el diseño de espectros de sitio específico para la región se debe desarrollar, ya que permitiría conocer las singularidades locales.</p>

scholarly journals Seismic hazard assessment for Adria

1999 ◽  
Vol 42 (6) ◽  
Author(s):  
D. Slejko ◽  
R. Camassi ◽  
I. Cecic ◽  
D. Herak ◽  
M. Herak ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Adriatic Sea ◽  
Seismic Hazard Assessment ◽  
Response Spectra ◽  
Hazard Map ◽  
Southern Apennines ◽  
Strong Earthquakes ◽  
Hazardous Area ◽  
Hazard Response ◽  
Lower Hazard

The Adriatic region was chosen as one of the test areas in the GSHAP program and, consequently, its seismic hazard was computed. The standard hazard map chosen by GSHAP represents PGA with a 475-year return period. Some other parameters, as the spectral acceleration and the uniform hazard response spectra for the main Adriatic towns, have been computed for a better representation of the regional hazard. The most hazardous area remains identified in the Cephalonia zone, where strong earthquakes frequently occur. The Southern Apennines are characterised by a slightly lower hazard, while the Adriatic Sea itself, the Poplain and the Apulian peninsula are almost aseismic.

Historical Earthquake Damages to Domed Structures in Istanbul

2015 ◽  
pp. 649-673 ◽  
Author(s):  
İhsan E. Bal ◽  
F. Gülten Gülay ◽  
Meltem Vatan ◽  
Eleni Smyrou
Keyword(s):  
Spatial Distribution ◽  
Seismic Hazard ◽  
Historical Earthquakes ◽  
Seismic Events ◽  
Historical Earthquake ◽  
Historical Buildings ◽  
The Past ◽  
Ottoman Architecture ◽  
Hazard Level ◽  
Earthquake Damages

This chapter discusses the domed structures in Istanbul, which are reported damaged during strong historical earthquakes. The attention is focused mostly to their domes, the most important component of the Byzantine and the Ottoman architecture. The significant shakings, together with their estimated epicenters and magnitudes, have been defined and the spatial distribution of the reported damages in the domed structures has been examined. It is underlined once more that the Historical Peninsula, which is where once Constantinople was located, has several vulnerable structures and high seismic hazard level at the same time. Certain structures are quite vulnerable to strong shakings and received significant damages multiple times. The chapter discusses the possible effects of the future seismic events on the historical buildings in Istanbul, based on the recorded damages occurred during the past seismic events.

Probabilistic Assessments of the Seismic Hazard in Northern Armenia (Spitak Region)

1996 ◽  
Vol 12 (2) ◽  
pp. 199-216 ◽  
Author(s):  
Yu K. Chernov ◽  
V. Yu Sokolov
Keyword(s):  
Seismic Hazard ◽  
Return Period ◽  
Response Spectra ◽  
Building Code ◽  
Probabilistic Assessment ◽  
Intensity Scale ◽  
Ground Acceleration ◽  
The Past ◽  
Design And Construction

The Spitak (Armenia) earthquake of December 7, 1988, (M=6.9) revealed the necessity to revise the assessments of seismic hazard obtained in the past. We used recently developed method for quantitative probabilistic assessment of seismic shaking to resolve the problem. The assessments of probable intensity of shaking in terms of MSK - 64 intensity scale showed that for this region the intensity with return period T=1000 years must be taken as MSK IX instead of MSK VII and MSK VIII assigned to Armenia by the building code. Probable Fourier and response spectra of ground acceleration have been estimated also, and may be used for design and construction of new building and structures in this region.

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