Generic predictive model for shear wave velocity profile at shallow depths in South Korea

Abstract

It is essential to adequately characterize the surface ground motion at sites for earthquake-resistant analysis and infrastructure design. The incorporation of the spatial variability of shear wave velocity (VS) profiles within a given site into the seismic site response analysis has become increasingly crucial. This study proposes a VS profile prediction model suitable for Korean regions conditioned on the time-averaged VS over the top 30 m (VS30). We collected 702 VS profiles across South Korea and fitted them to the analytical function proposed by a previous study, the parameters of which are subsequently regressed on VS30. The VS profiles predicted using the model with the derived parameters are remarkably similar to the measured VS profiles not included in curve fitting. The goodness-of-fit scores for the proposed model's predictions relative to the measured VS profiles exhibit an improvement of approximately 6 and 10 % compared to the VS profiles predicted by the model of a previous study. This model is expected to be used for preliminary assessments of site amplification alongside methods for predicting VS30 or the previously evaluated experimental dispersion curves or VS profiles available from a site adjacent to the target sites.