scholarly journals Monte Carlo Based Seismic Hazard Model for Southern Ghana

2018 ◽  
Vol 4 (7) ◽  
pp. 1510 ◽  
Author(s):  
Jack Banahene Osei ◽  
Mark Adom-Asamoah ◽  
Ahmed Ali Awadallah Ahmed ◽  
Eugene Boasiako Antwi
Keyword(s):  
Monte Carlo ◽  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Peak Ground Acceleration ◽  
Seismic Hazard Assessment ◽  
Hazard Model ◽  
Ground Acceleration ◽  
Probability Of Exceedance ◽  
Southern Ghana

Seismic hazard assessment involves quantifying the likely ground motion intensities to be expected at a particular site or region. It is a crucial aspect of any seismic hazard mitigation program. The conventional probabilistic seismic hazard assessment is highly reliant on the past seismic activities in a particular region. However, for regions with lower rates of seismicity, where seismological data is scanty, it would seem desirable to use a stochastic modelling (Monte Carlo based) approach. This study presents a Monte Carlo simulation hazard model for Southern Ghana. Six sites are selected in order to determine their expected ground motion intensities (peak ground acceleration and spectral acceleration). Results revealed that Accra and Tema as the highly seismic cities in Southern Ghana, with Ho and Cape Coast having relatively lower seismicities. The expected peak ground acceleration corresponding to a 10% probability of exceedance in 50 years for the proposed seismic hazard model was as high as 0.06 g for the cities considered. However, at the rather extreme 2% probability of exceedance in 50 years, a PGA of 0.5 g can be anticipated. Evidently, the 2% in 50 years uniform hazard spectrum for the highly seismic cities recorded high spectral accelerations, at a natural vibrational period within the ranges of about 0.1-0.3 sec. This indicates that low-rise structures in these cities may be exposed to high seismic risk.

scholarly journals Seismic Hazard Assessment for Thuong Tan-Tan My Quarries (Vietnam)

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Cao Dinh Trong ◽  
Xuan-Nam BUI ◽  
Pham NAM HUNG ◽  
Thai ANH TUAN ◽  
Mai XUAN BACH ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Peak Ground Acceleration ◽  
Seismic Hazard Assessment ◽  
Earthquake Hazard ◽  
Peak Ground Velocity ◽  
Ground Displacement ◽  
Ground Acceleration ◽  
Probability Of Exceedance ◽  
S Peak

This paper presents the seismic hazard assessment for Thuong Tan-Tan My quarries in Di An commune, Binh Duong province, Vietnam. Combination methods of gravity and magneto-telluric were used to estimate the dip angle and the width of the seismic source. The highest water column of 160 m will cause direct stress on the reservoir bottom with a maximum value of 1535.600 kPa and Coulomb stress of 68.693 kPa (at a depth of 2 km). The typical components of natural earthquake hazard (Mn.max = 5.0, depth of 10 km) in Thuong Tan - Tan My reservoir have the following values: peak ground acceleration PGA = 0.073 g ÷ 0.212 g; peak ground velocity PGV = 2.662 cm/s ÷ 7.984 cm/s; peak ground displacement PGD = 0.706 cm ÷ 1.918 cm at 10% probability of exceedance in 50 years. The typical components of triggered earthquake hazard (Mtr.max = 3.5, depth of 6 km) in Thuong Tan - Tan My reservoir have the following values: peak ground acceleration PGA = 0.024 g ÷ 0.172 g; peak ground velocity PGV = 0 ÷ 5.484 cm/s; peak ground displacement PGD = 0.061 cm ÷ 0.461 cm at 10% probability of exceedance in 50 years.

scholarly journals Probabilistic seismic hazard assessment in Greece – Part 1: Engineering ground motion parameters

2010 ◽  
Vol 10 (1) ◽  
pp. 25-39 ◽  
Author(s):  
G-A. Tselentis ◽  
L. Danciu
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Peak Ground Acceleration ◽  
Seismic Hazard Assessment ◽  
Peak Ground Velocity ◽  
Probabilistic Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard ◽  
Arias Intensity ◽  
Ground Acceleration ◽  
Cumulative Absolute Velocity

Abstract. Seismic hazard assessment represents a basic tool for rational planning and designing in seismic prone areas. In the present study, a probabilistic seismic hazard assessment in terms of peak ground acceleration, peak ground velocity, Arias intensity and cumulative absolute velocity computed with a 0.05 g acceleration threshold, has been carried out for Greece. The output of the hazard computation produced probabilistic hazard maps for all the above parameters estimated for a fixed return period of 475 years. From these maps the estimated values are reported for 52 Greek municipalities. Additionally, we have obtained a set of probabilistic maps of engineering significance: a probabilistic macroseismic intensity map, depicting the Modified Mercalli Intensity scale obtained from the estimated peak ground velocity and a probabilistic seismic-landslide map based on a simplified conversion of the estimated Arias intensity and peak ground acceleration into Newmark's displacement.

scholarly journals Probabilistic seismic hazard assessment of Bishkek, Kyrgyzstan, considering empirically estimated site effects

2015 ◽  
Vol 58 (1) ◽  
Author(s):  
Shahid Ullah ◽  
Dino Bindi ◽  
Marco Pilz ◽  
Stefano Parolai
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Site Effects ◽  
Response Spectrum ◽  
Seismic Hazard Assessment ◽  
Geological Structure ◽  
Probabilistic Seismic Hazard Assessment ◽  
Site Classification ◽  
Ground Acceleration

<p>It is well known that variability in the surface geology potentially leads to the modification of earthquake-induced ground motion over short distances. Although this effect is of major importance when seismic hazard is assessed at the urban level, it is very often not appropriately accounted for. In this paper, we present a first attempt at taking into account the influence of the shallow geological structure on the seismic hazard assessment for Bishkek, Kyrgyzstan, using a proxy (Vs30) that has been estimated from in situ seismic noise array analyses, and considering response spectral ratios calculated by analyzing a series of earthquake recordings of a temporary seismic network. To highlight the spatial variability of the observed ground motion, the obtained results are compared with those estimated assuming a homogeneous Vs30 value over the whole urban area. The seismic hazard is evaluated in terms of peak ground acceleration (PGA) and spectral acceleration (SA) at different periods (frequencies). The presented results consider the values obtained for a 10% probability of exceedance in 50 years. The largest SA estimated considering a rock site classification of the area (0.43 g) is observed for a period of 0.1 s (10 Hz), while the maximum PGA reaches 0.21 g. When site effects are included through the Vs30 proxy in the seismic hazard calculation, the largest SA, 0.67 g, is obtained for a period of 0.3 s (about 3.3 Hz). In terms of PGA, in this case the largest estimated value reaches 0.31 g in the northern part of the town. When the variability of ground motion is accounted for through response spectrum ratios, the largest SA reaches a value as high as 1.39 g at a period of 0.5 s. In general, considering site effects in the seismic hazard assessment of Bishkek leads to an increase of seismic hazard in the north of the city, which is thus identified as the most hazardous part within the study area and which is more far away from the faults.</p>

Seismic Hazard Assessment: Simultaneous Effect of Earthquakes at Close and Distant Sites

2002 ◽  
Vol 18 (4) ◽  
pp. 615-629 ◽  
Author(s):  
Gideon Leonard ◽  
David M. Steinberg
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Peak Ground Acceleration ◽  
Seismic Hazard Assessment ◽  
Dead Sea ◽  
Probabilistic Assessment ◽  
Ground Acceleration ◽  
Emergency Relief ◽  
A Site ◽  
Relief Efforts

A modified version of seismic hazard assessment, directed toward planning of emergency relief efforts, is proposed. The method begins with a probabilistic hazard assessment to determine a reference peak ground acceleration (PGA) at a near site, rather than using a reference earthquake of a given magnitude. The reference PGA then serves as a basis for a probabilistic assessment of PGA at more distant sites. The ideas are illustrated by studying seismic hazard for Northern Israel from earthquakes on the northern section of the Dead Sea Rift (DSR). The reference PGA at a site 10 km from the DSR is taken to be 0.3 g, which has a return period estimated to be 320 years. Given an event with PGA of 0.3 g at 10 km, the subsequent analysis for distant sites shows that there is less than a 31% probability of PGA above 0.1 g at 30 km and an 8% probability that the PGA at 50 km will exceed 0.1 g.

scholarly journals Seismic Hazard Assessment of Shigo Kas Hydro-Power Project (Khyber Pakhtunkhwa, Pakistan)

Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 349
Author(s):  
Muhammad Abid ◽  
Haytham F. Isleem ◽  
Khan Shahzada ◽  
Afed Ullah Khan ◽  
Muhammad Kamal Shah ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Peak Ground Acceleration ◽  
Soil Analysis ◽  
Safety Evaluation ◽  
Seismic Hazard Assessment ◽  
Deep Soil ◽  
Ground Acceleration ◽  
Hydro Power ◽  
Local Site

In this paper, a seismic hazard assessment (SHA) of the Shigo Kas hydropower project has been performed by deterministic and probabilistic approaches. The previously developed MATLAB-based code has been used for deterministic SHA, incorporating local site effects through deep soil analysis. On the other hand, for probabilistic SHA, CRISIS 2007 has been used through diffuse areal source zones. The latest updated earthquake instrumental and historical catalogs have been developed. Based on the recommendations of the International Commission on Large Dams, peak ground acceleration (PGA) values for the maximum credible earthquake (MCE), safety evaluation earthquake (SEE), design basis earthquake (DBE) and operating basis earthquake (OBE) have been assessed, which are 0.50 g, 0.68 g, 0.35 g and 0.24 g, respectively, at the intake location, and 0.50 g, 0.61 g, 0.30 g and 0.22 g, respectively, at the powerhouse location. Hazard maps have been developed for scenario-based earthquakes (MCE) and for the peak ground acceleration of 145-, 475- and 2500-year return periods. The de-aggregation process has evaluated the combined effects of magnitude and distance. At a distance of 30 to 70 km from the earthquake source, earthquakes of magnitude 5 Mw to 5.6 Mw and 5.9 Mw to 6.5 Mw are more hazardous for the current project.

scholarly journals Probabilistic Seismic Hazards Analysis of Ambikapur-Chhattisgarh (India)

2021 ◽  
Vol 9 (2) ◽  
pp. 83-91
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Peak Ground Acceleration ◽  
Hazard Analysis ◽  
Seismic Hazard Analysis ◽  
Probabilistic Seismic Hazard ◽  
Attenuation Relationship ◽  
Ground Acceleration ◽  
Probability Of Exceedance ◽  
Maximum Peak

The present study reveals the seismic hazard analysis of district headquarter Ambikapur, in the state of Chhattisgarh. Usually, seismic hazard study attempts to analyze two different kinds of anticipated ground motions, “the Deterministic Seismic Hazard Analysis (DSHA)” and “the Probabilistic Seismic Hazard Analysis (PSHA)”. The maximum Peak Ground Acceleration (PGA) has been estimated by using Iyengar and Raghu Kanth (2004) attenuation relationship. The regional recurrences relation is obtained by using available historical data and 33 numbers of seismic sources (liner faults) that are likely to cause ground motion, around the study area. The probabilistic seismic hazard analysis has been applied over Ambikapur, to assess the probability of exceedance for various PGA(g)values the seismic hazard curve has been developed by using Raghu Kanth and Iyengar (2007) attenuation relationship. Theprobability of exceedance for PGA(g) values as 0.01g,0.05g,0.10g,0.15g for their corresponding return periods have also been assessed. The liner seismic source having length 46kM, produced maximum peak ground motion as 0.15259g for recurrence period of 100 years. For Ambikapur district headquarter the probability of exceedance for 0.1g with a return period of 8788 years is estimated as 63.22%. Maximum Peak Ground Acceleration value and % probability of exceedance reflects that the seismicity of Ambikapur district headquarter is found to have exceeded from 0.1g as recommended by IS:1893 (Part 1): 2016 (Sixth Revision) for Chhattisgarh. Hence, it is recommended from present study that, Ambikapur should be included in zone III instead of zone II.

scholarly journals Seismic Hazard Assessment for the Tianshui Urban Area, Gansu Province, China

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Zhenming Wang ◽  
David T. Butler ◽  
Edward W. Woolery ◽  
Lanmin Wang
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Seismic Design ◽  
Hazard Analysis ◽  
Seismic Hazard Assessment ◽  
Gansu Province ◽  
Mitigation Measures ◽  
Peak Ground Velocity ◽  
Ground Acceleration ◽  
Acceleration Time Histories

A scenario seismic hazard analysis was performed for the city of Tianshui. The scenario hazard analysis utilized the best available geologic and seismological information as well as composite source model (i.e., ground motion simulation) to derive ground motion hazards in terms of acceleration time histories, peak values (e.g., peak ground acceleration and peak ground velocity), and response spectra. This study confirms that Tianshui is facing significant seismic hazard, and certain mitigation measures, such as better seismic design for buildings and other structures, should be developed and implemented. This study shows that PGA of 0.3 g (equivalent to Chinese intensity VIII) should be considered for seismic design of general building and PGA of 0.4 g (equivalent to Chinese intensity IX) for seismic design of critical facility in Tianshui.

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