지반정보 통합분석을 통한 서울시 지진 정밀구역화 연구

초록

Seismic microzonation is a critical process for seismic hazard assessment and earthquake-resistant structural design, where the acquisition of shear wave velocity (Vs) profiles is essential for site classification and response analysis. However, in megacities such as Seoul, geophysical surveys are often limited due to spatial and financial constraints. This study performs a seismic microzonation of the entire Seoul area by integrating approximately 22,000 borehole datasets including stratigraphy and Standard Penetration Test (SPT) results with 241 geophysical survey records. A probabilistic and spatial outlier removal procedure was conducted to refine the dataset, followed by the application of a geostatistical interpolation method (kriging) to estimate key site response parameters, including bedrock depth (H), average shear wave velocity of the upper soil layer (VS,soil), 30 meter average shear wave velocity (VS30), and site period (TG). Site classification based on the Korean seismic design standard (KDS) revealed that the majority of Seoul falls under classes S2 (71%) and S3 (2%), with class S4 (14%) concentrated around the Hangang river basin. Moreover, classification based on site period (TG) derived from individual boreholes indicates the need for refinement in the current KDS classification system. The integrated analytical framework and seismic microzonation results proposed in this study are expected to serve as a fundamental dataset for seismic hazard prediction and earthquake mitigation planning in Seoul.

키워드