Seismic Hazard Analysis for the Debrezeit Area
| dc.contributor.advisor | Mammo, Tilahun (Professor) | |
| dc.contributor.advisor | Alene, Mulugeta (PhD) | |
| dc.contributor.author | Dander, Kasahun | |
| dc.date.accessioned | 2020-11-11T11:48:50Z | |
| dc.date.accessioned | 2023-11-09T14:12:01Z | |
| dc.date.available | 2020-11-11T11:48:50Z | |
| dc.date.available | 2023-11-09T14:12:01Z | |
| dc.date.issued | 2015-05-05 | |
| dc.description.abstract | In this thesis work we have presented a seismic hazard investigation conducted at Debrezite area, central Ethiopia. In this work we carried out a probabilistic seismic hazard analysis with an emphasis on the local site conditions. The analyses were carried out using the ISC-GEM (International Seismological Center and Global Earthquake Model) earthquake catalogue available over a radius of 200 km around Debrezeit city considering destructive earthquakes from 1906 to 2011. The analysis was also carried out by considering known seismogenic sources that are identified on the basis of seismicity and tectonics. Earthquake data from ISC-GEM (International Seismological Center and Global Earthquake Model) catalogue were analyzed statistically and Gutenburg-Richter recurrence relation is used to obtain the b-value of 0.67, 1.03 and 1.11 for the three seismic zones: Main Ethiopian Rift, Afar and Escarpment respectively that are considered to generate earthquakes that affect the Debrezeit area. Seismic refraction data was collected at Kuriftu site, Debrezeit using McSEIS-SX24 seismogram. Multi-Channel Analysis of Surface Waves method is used to analyze the surface waves and determine the shear wave velocity at the depth of 30m. SeisImager/ SW software were used to produce a 2-D shear-wave velocity section. The shear wave velocity observed at Kuriftu site has the mean Vs30 value of 360m/s. Therefore, according to the National Earthquake Hazard Reduction Program classification the site can be classified under soil class C. Based on the site classification value, we can conclude that the main part of the study area is under substantial risk of soil amplification. After the implementation of a seismic hazard analysis by using CRISIS2012 software, the probabilistic seismic hazard curves: Exceedance probability and Uniform Hazard Spectrum curves were developed based on the selected attenuation relationship, with a probability of exceedance of 10% in 50, 100, 250 and 500 years to a return period of 475 years for bed rock condition and considering local site effects. On the other hand the highest hazard levels were determined at soil site for Debrezeit, the peak ground acceleration and spectral acceleration values calculated based on attenuation relationship by (Campbell and Bozorgnia 2008) were found to be applicable for 10% probability of exceedance in 50, 100, 250 and 500 years, taking into consideration the fact that a considerable portion of the city is founded over alluviums. | en_US |
| dc.identifier.uri | http://10.90.10.223:4000/handle/123456789/23183 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Debrezeit | en_US |
| dc.subject | Earthquake | en_US |
| dc.subject | B-Value | en_US |
| dc.subject | Hazard Curve | en_US |
| dc.subject | Attenuation Relationship | en_US |
| dc.subject | Peak Ground Acceleration | en_US |
| dc.title | Seismic Hazard Analysis for the Debrezeit Area | en_US |
| dc.type | Thesis | en_US |