Seismic Hazard Analysis for the Bangalore Region

Sitharam, T. G.; Anbazhagan, P.

doi:10.1007/s11069-006-0012-z

Cited by 94 publications

(34 citation statements)

References 15 publications

(11 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The PHA values in the central region of South India, around Bangalore, are in the range of 0.11 g to 0.16 g. This region also shows higher seismic hazard than the code (BIS-1893(BIS- , 2002) specification. The PHA value for the Bangalore region reported by Sitharam and Anbazhagan (2007) is 0.146 g, which also matches with the present study. Similar results were obtained in the studies by Jaiswal and Sinha (2007) for Koyna region 1.0E-10…”

Section: Resultssupporting

confidence: 92%

“…The shortest and longest distance from each source to the centre of the grid is calculated. The hypocentral distance was calculated by considering a focal depth of 15 km, similar to the one used for DSHA by Sitharam et al (2006) and Sitharam and Anbazhagan (2007). A probable source zone depth of 10 km has been considered by Bhatia et al (1997) in an exercise to develop seismic hazard map of the shield region of India in GSHAP.…”

Section: Seismic Hazard Analysismentioning

confidence: 99%

See 1 more Smart Citation

Estimation of peak ground acceleration and spectral acceleration for South India with local site effects: probabilistic approach

Vipin

Anbazhagan

Sitharam

2009

Nat. Hazards Earth Syst. Sci.

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Resultssupporting

confidence: 92%

Section: Seismic Hazard Analysismentioning

confidence: 99%

Estimation of peak ground acceleration and spectral acceleration for South India with local site effects: probabilistic approach

Vipin

Anbazhagan

Sitharam

2009

Nat. Hazards Earth Syst. Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…SITHARAM and ANBAZHAGAN (2007) have presented the DSHA method to estimate the ground motion in a site using seismogenic sources and MCE for Bangalore in southern India. The DSHA method to estimate the ground motion at a site is not appropriate because prediction of ground motion in a site with the DSHA method considers just one maximum magnitude scenario earthquake with a shortest source to site (BOMMER and ABRAHAMSON, 2006) and neglected the other sources surrounding the site.…”

Section: Methodsmentioning

confidence: 99%

A New Insight into Probabilistic Seismic Hazard Analysis for Central India

Mandal

Shukla

Khan

et al. 2013

Pure Appl. Geophys.

View full text Add to dashboard Cite

Abstract-The Son-Narmada-Tapti lineament and its surroundings of Central India (CI) is the second most important tectonic regime following the converging margin along HimalayasMyanmar-Andaman of the Indian sub-continent, which attracted several geoscientists to assess its seismic hazard potential. Our study area, a part of CI, is bounded between latitudes 18°-26°N and longitudes 73°-83°E, representing a stable part of Peninsular India. Past damaging moderate magnitude earthquakes as well as continuing microseismicity in the area provided enough data for seismological study. Our estimates based on regional GutenbergRichter relationship showed lower b values (i.e., between 0.68 and 0.76) from the average for the study area. The Probabilistic Seismic Hazard Analysis carried out over the area with a radius of *300 km encircling Bhopal yielded a conspicuous relationship between earthquake return period (T) and peak ground acceleration (PGA). Analyses of T and PGA shows that PGA value at bedrock varies from 0.08 to 0.15 g for 10 % (T = 475 years) and 2 % (T = 2,475 years) probabilities exceeding 50 years, respectively. We establish the empirical relationships ZPA These demonstrate that the ZPA values decrease with increasing shear wave velocity, suggesting a diagnostic indicator for designing the structures at a specific site of interest. The predictive designed response spectra generated at a site for periods up to 4.0 s at 10 and 2 % probability of exceedance of ground motion for 50 years can be used for designing duration dependent structures of variable vertical dimension. We infer that this concept of assimilating uniform hazard response spectra and predictive design at 10 and 2 % probability of exceedance in 50 years at 5 % damping at bedrocks of different categories may offer potential inputs for designing earthquake resistant structures of variable dimensions for the CI region under the National Earthquake Hazard Reduction Program for India.

show abstract

“…However, only a limited number of recorded acceleration time histories, especially for India and China, are available for carrying out site response analyses. For regions having limited or no seismic record, synthetic ground motion or ground motions from similar tectonic regions may be considered a viable alternative (Sitharam and Anbazhagan 2007). Seismological models developed by Boore (1983Boore ( , 2003 have been widely used for the generation of synthetic acceleration time histories (Atkinson and Boore 1995;Hwang and Huo 1997).…”

Section: Earthquake Ground Motion Records For Site Response Studymentioning

confidence: 99%

“…Seismological models developed by Boore (1983Boore ( , 2003 have been widely used for the generation of synthetic acceleration time histories (Atkinson and Boore 1995;Hwang and Huo 1997). To carry out site response analyses under moderate earthquake ground motions, a synthetic ground motion generated by Sitharam and Anbazhagan (2007) using a seismological modeling approach has been used in this study. In Fig.…”

Section: Earthquake Ground Motion Records For Site Response Studymentioning

confidence: 99%

Influence of Rock Depth on Seismic Site Classification for Shallow Bedrock Regions

2013

Self Cite

View full text Add to dashboard Cite

Seismic site classifications are used to represent site effects for estimating hazard parameters (response spectral ordinates) at the soil surface. Seismic site classifications have generally been carried out using average shear wave velocity and/or standard penetration test n-values of top 30-m soil layers, according to the recommendations of the National Earthquake Hazards Reduction Program (NEHRP) or the International Building Code (IBC). The site classification system in the NEHRP and the IBC is based on the studies carried out in the United States where soil layers extend up to several hundred meters before reaching any distinct soil-bedrock interface and may not be directly applicable to other regions, especially in regions having shallow geological deposits. This paper investigates the influence of rock depth on site classes based on the recommendations of the NEHRP and the IBC. For this study, soil sites having a wide range of average shear wave velocities (or standard penetration test n-values) have been collected from different parts of Australia, China, and India. Shear wave velocities of rock layers underneath soil layers have also been collected at depths from a few meters to 180 m. It is shown that a site classification system based on the top 30-m soil layers often represents stiffer site classes for soil sites having shallow rock depths (rock depths less than 25 m from the soil surface). A new site classification system based on average soil thickness up to engineering bedrock has been proposed herein, which is considered more representative for soil sites in shallow bedrock regions. It has been observed that response spectral ordinates, amplification factors, and site periods estimated using onedimensional shear wave analysis considering the depth of engineering bedrock are different from those Abstract: Seismic site classifications are used to represent site effects for estimating hazard parameters (response spectral ordinates) at the soil surface. Seismic site classifications have generally been carried out using average shear wave velocity and/or standard penetration test n-values of top 30-m soil layers, according to the recommendations of the National Earthquake Hazards Reduction Program (NEHRP) or the International Building Code (IBC). The site classification system in the NEHRP and the IBC is based on the studies carried out in the United States where soil layers extend up to several hundred meters before reaching any distinct soil-bedrock interface and may not be directly applicable to other regions, especially in regions having shallow geological deposits. This paper investigates the influence of rock depth on site classes based on the recommendations of the NEHRP and the IBC. For this study, soil sites having a wide range of average shear wave velocities (or standard penetration test n-values) have been collected from different parts of Australia, China, and India. Shear wave velocities of rock layers underneath soil layers have also been collected at depths from a few meters ...

show abstract

Seismic Hazard Analysis for the Bangalore Region

Cited by 94 publications

References 15 publications

Estimation of peak ground acceleration and spectral acceleration for South India with local site effects: probabilistic approach

Estimation of peak ground acceleration and spectral acceleration for South India with local site effects: probabilistic approach

A New Insight into Probabilistic Seismic Hazard Analysis for Central India

Influence of Rock Depth on Seismic Site Classification for Shallow Bedrock Regions

Contact Info

Product

Resources

About