Özet:

The main goal of the study is to define the design input motion scenarios for the future microzonation study. The study of the “Earthquake hazard Assessment in Duzce” is performed for the seismic hazard for the city of Duzce in order to get the design ground motion parameters for the next microzonation study. The main goal of the present study is to give briefly the steps and the uncertainties derived from the performing deterministic seismic hazard study for the city of Duzce based exclusively on the existing data and the seismicity of the region. This study uses all available sources of information, technical papers and research works performed so far. The seismotectonic environment of the area is very active, however there are certain uncertainties (to our knowledge) regarding the characteristic of the seismic source zones, the fault length, the magnitudes assigned to the faults, the seismicity parameters, the seismic history of the area, the attenuation relationships etc. During the few past years several research studies have contributed in better understanding the seismotectonic and geological background of the region. There are still a lot of parameters which are poorly known in order to provide more reliable seismological information of the area. Seismic hazard in Duzce was performed using uniform seismic zones (USZ). The seismic hazard was performed using a poisoning approach for mean return periods of 100 and 475 years. In the Seismotectonic zonation criteria; the seismic sources selected to perform a seismic hazard analysis were determined by Kayabali K (2002). In total  14 seismic sources were delineated in Turkey based mostly on Erdik et al (1985) and Yaltirak et al (1998) works. As a result, we have computed the PGA values and the acceleration response spectra for soft soil and rock (considered as outcrop) conditions in Duzce and for two mean return periods. In addition, several other comparisons with real records of previous earthquakes and seismic hazard studies will enhance the reliability of the obtained results. The design PGA value for rock (or outcrop) conditions and for 250 years return period is most probably between 0.3g and 0.35g. For 475 years return period it will be almost the double of it (we could accept in a reasonable way a PGA = 0.60g). These values will be further validated and then will be used, as incident peak ground accelerations, of a uniform incident ground motion, at the bedrock basement of Duzce for the detailed microzonation study of Duzce.  

Anahtar Kelimeler: