Evaluation of Shear Wave Velocity Prediction Models from Standard Penetration Test N Values Depending on Geologic Attributes: A Case Study in Busan, South Korea

This study evaluates the effectiveness of the previously proposed Standard Penetration Test (SPT) N and shear wave velocity (V-S) models in relation to the geological attributes of the Busan region, situated in the southeastern part of the Korean peninsula. The multiple empirical N-V-S models, which used datasets collected from different regions in South Korea, resulted in distinct N-V-S trends across models. To validate the predictive capabilities of each model, this study gathered boring logs containing SPT N and V-S measurements within the Busan region, followed by a thorough residual analysis. The Busan area encompasses a delta region to the west and erosion basins within the mountains and hills to the east. Despite the relatively confined geographical scope, we found that models developed using data from fill areas exhibit superior performance for the delta region (western Busan), while models constructed from datasets within erosion basins perform better for the erosion basin region (eastern Busan). This comparative examination supports the dependence of the N-V-S model on geologic attributes and offers the valuable insight that N-V-S models developed with analogous geological attributes should be employed when estimating V-S from SPT N values.