Site Specific Liquefaction Analysis for Infrastructure Resilience through Geotechnical and Geological Perspectives in Medan City, Indonesia

Abstract This study evaluates the liquefaction potential of an infrastructure site in Medan City, North Sumatra, using a combined geotechnical and geological approach. Geotechnical data used during research included Standard Penetration Test (SPT), soil boring logs, and Peak Ground Acceleration (PGA). The data mentioned were used to calculate Cyclic Stress Ratio (CSR), Cyclic Resistance Ratio (CRR), and Factor of Safety (SF) against liquefaction. The analysis was conducted under a seismic scenario with a moment magnitude (Mw) of 7.0. Inverse Distance Weight (IDW) implemented as the main interpolation method for SF mapping. Geological inputs included regional geological maps, digital elevation models (DEM), contour data, slope, landuse and soil type classification to categorize the liquefaction potential using TADGS method. Results indicate a high local liquefaction potential at depths greater than 15 meters, where SF values fall below 1.0, suggesting unstable soil behavior under cyclic loading. The site is underlain by sedimentary rock formations, which are generally more susceptible to liquefaction due to their unconsolidated nature and high water content. Furthermore, based on TADGS method, the site area categorized as moderate to liquefaction susceptibility. These findings highlight the importance of site-specific seismic hazard assessments in infrastructure planning. Integrating geotechnical and geological data provides a robust framework for evaluating ground stability in earthquake-prone regions.