A large amount of geotechnical investigation data is essential for the highly reliable design of geotechnical structure at a construction site. The number of geotechnical investigations, however, has been generally insufficient and spatially biased owing to economic and spatial-temporal limitations. In this study, a geotechnical three-dimensional spatial modeling was implemented using an optimized geostatistical interpolation approach at a bridge construction site in the south-central part of the Korean peninsula. The geotechnical investigation data were collected and standardized for the construction of a geo-database. For the site-specific stratification, a kriging-based integration of the geo-layers and the seismic velocity from a seismic refraction survey were applied. The value from a standard penetration test (SPT)-N of an uninvestigated location was predicted using parametric and nonparametric geostatistical methods. We accomplished three-dimensional spatial interpolations using ordinary kriging, a sequential Gaussian simulation with a normal score transformed dataset, and a sequential indicator simulation using the geodatabase. A leave-one-out cross validation was carried out to quantitatively evaluate the reliability of the three-dimensional modeling. Finally, a three-dimensional geotechnical spatial model assigned with subsurface stratification and SPT-N values was constructed using the sequential Gaussian simulation.

The increasing frequency of earthquake events worldwide, particularly in South Korea, necessitates detailed seismic hazard assessments to mitigate the risks to urban infrastructure. This study addresses this pressing need by developing a comprehensive multi-hazard assessment framework specific to the Gyeonggi-do Province. By leveraging advanced geospatial computation techniques and geographic information systems, this study integrated geotechnical data, terrain information, and building inventories to evaluate seismic site effects, earthquake-induced landslide hazards, and structural vulnerability. This method uses geostatistical methods to construct geotechnical spatial grids that correlate site-specific seismic responses to potential hazards. The key findings revealed significant variations in seismic site responses owing to local subsurface characteristics, emphasizing the importance of site-specific seismic hazard maps for urban disaster preparedness. The framework’s effectiveness was validated by analyzing the 2017 Pohang earthquake, which demonstrated a strong correlation between predicted and observed damage. This study highlights the importance of ongoing seismic hazard assessment methodology development and advocates interdisciplinary collaboration to improve urban resilience, ultimately protecting communities from the impacts of future earthquakes.

Earthquake hazards, such as strong ground motion, liquefaction, and landslides, pose significant threats to structures built on seismically vulnerable, loose, and saturated sandy soils. Therefore, a structural failure evaluation method that accounts for site-specific seismic responses is essential for developing effective and appropriate earthquake hazard mitigation strategies. In this study, a real-time assessment framework for structural seismic susceptibility is developed. To evaluate structural susceptibility to earthquakes, seismic fragility functions are employed as thresholds for structural failure and are linked to a geotechnical spatial grid that incorporates correlation equations for seismic load determination. The real-time assessment consists of the following procedures. First, the geotechnical spatial grid is constructed based on the geostatistical method to estimate the site-specific site response to be correlated with the earthquake hazard potential. Second, the peak ground accelerations are determined from seismic load correlation and assigned to the geotechnical spatial grid. Third, the damage grade of structure is determined by calculating the failure probabilities of defined damage levels and integrating the geotechnical spatial grids for the target structure in real time. The proposed assessment was simulated at Incheon Port, South Korea, using both an actual earthquake event (the 2017 Pohang Earthquake) and a hypothetical earthquake scenario.