Regional Estimation of Site-specific Seismic Response by Spatial Zoning on Site Period at Daegu in Korea

Most of earthquake-induced geotechnical hazards have been caused by the site effects relating to the amplification of ground motion, which are strongly influenced by the local geologic conditions such as soil thickness or bedrock depth and soil stiffness. In this study, an integrated GIS-based information system for geotechnical data, called geotechnical information system (GTIS), was constructed to establish a regional counterplan against earthquake-induced hazards at an urban area, Daegu, in Korea. To build the GTIS for the area of interesting, pre-existing geotechnical data collections were performed across the extended area including the study area and a walk-over site survey was additionally carried out to acquire surface geo-knowledge data. For practical application of the GTIS used to estimate the site-specific seismic response across the area of interesting, seismic microzoning map of the characteristic site period was created and presented as regional synthetic strategy for earthquake-induced hazards prediction. In addition, seismic zonation of site classification according to the spatial distribution of the site period was also performed to determine the site amplification coefficients for seismic design and seismic performance evaluation at any site in the study area.