Ground-motion prediction equation for South Korea based on recent earthquake records

Abstract

A ground-motion prediction equation (GMPE) for the Korean Peninsula, especially for South Korea, is developed based on synthetic ground motions generated using a ground motion model derived from instrumental records from 11 recent earthquakes of M-L>4.5 in Korea, including the Gyeongju earthquake of Sept. 12. 2016 (M(L)5.8). PSAs of one standard deviation from the developed GMPE with M-W 6.5 at hypocentral distances of 15 km and 25 km are compared to the design spectrum (soil condition, S-B) of the Korean Building Code 2016 (KBC), indicating that: (1) PSAs at short periods around 0.2 sec can be 1.5 times larger than the corresponding KBC PSA, and (2) SD's at periods longer than 2 sec do not exceed 8 cm. Although this comparison of the design spectrum with those of the GMPE developed herein intends to identify the characteristics of the scenario earthquake in a lower-seismicity region such as South Korea, it does not mean that the current design spectrum should be modified accordingly. To develop a design spectrum compatible with the Korean Peninsula, more systematic research using probabilistic seismic hazard analysis is necessary in the future.