Yeni nesil azalım ilişkilerinin kullanılarak İzmir için tasarım spektrumlarının geliştirilmesi

This study is about the development of probabilistic hazard maps of İzmir in terms of `ground acceleration? values for three different probability of exceedance levels in 50 years at the bedrock.Earthquake magnitudes are defined in different scales all over the world. This causes the collected data to be in different units. In order to use these data correctly, the magnitude data of İzmir and its vicinities were converted to the generally preferred scale of moment of magnitude, after establishment of the correlations between the data pairs.Next step in the study was to define the seismic zones for İzmir. Using the faults properties taken from several references and the location of earthquake epicenters eleven seismic zones were specified. During risk analyses each zone was taken into consideration separately and the annual reoccurrence relationships for each source zone were obtained.The earthquake effect was estimated using new generation attenuation relationships postulated by Campbell and Bozorgnia (2008), Brian, Chiou and Youngs (2008) and Boore and Atkinson (2007). The implementation of the probabilistic seismic hazard model was done by using the Seisrisk III software. As they are essential for the development of design spectrum, the calculations were done for two different spectral periods such as T=1.0 second and 0.2 second. It was found that the new attenuation relationships suggested by Campbell and Bozorgnia (2008) and Brian et al (2008) yielded similar results. Among the parameters taken into consideration in the attenuation models the parameter related with the depth to bedrock with 1000 kilometer per second shear wave velocity seems to affect the obtained results more significantly resulting in the computation of higher values of accelerations along the coastline where the depth to the rock is much deeper.