Uniform risk in site-specific seismic hazard analysis

Abstract

A site-specific seismic hazard analysis may be considered as composed of four consecutive stages that can be assumed independent and thus evaluated separately. The first stage is the estimation of the design earthquake magnitude based on seismological and geological data in the region. The second stage is the estimation of the source distance of the design earthquake. The third stage is the estimation of the design earthquake characteristics at the bedrock based on attenuation relationships. The fourth stage is the estimation of design earthquake characteristics on the ground surface based on the local geotechnical site conditions. Each of these stages involves various degrees of uncertainties therefore probabilistic approaches need to be adopted to determine the exceedence probabilities in these four stages to evaluate the overall uncertainty. A case study conducted for a site in Bursa located in western Turkey will be presented for determining the design earthquake characteristics with respect to a constant exceedence probability in these four stages.