Assessment of new Korean site classification and design response spectra

A site classification scheme and design response spectra (DRS) were implemented in July 2017 as a part of new minimum requirements for general seismic design in Korea. However, verification using the 2016 Gyeongju earthquake, the largest earthquake in the history of instrumental seismic observation in Korea, was not conducted due to the schedule limitations of the public hearing process. In this study, site classification schemes and corresponding DRS curves were compared with the 2016 Gyeongju earthquake records to assess the superiority of the new code compared with other Korean seismic design codes. Seismic stations were categorised into relevant site class according to each seismic design code based on the subsurface geotechnical information at the stations, and the earthquake records were gathered depending on the site class. Finally, response spectra were converted and compared with the corresponding DRS curve given by each seismic design code. The comparisons reveal that the classification scheme and DRS included in the new Korean requirements accurately reflect as-measured conditions and yield more reliable results than other Korean codes.