Kajian Komparatif Pendekatan Geoteknik dan Geofisika terhadap Pemodelan Potensi Likuifaksi di Kawasan NYIA

Abstract

The Special Region of Yogyakarta (DIY), particularly the New Yogyakarta International Airport (NYIA) area, lies in a region highly susceptible to liquefaction due to significant seismic activity and unique geological conditions. This study aims to analyze the liquefaction potential using geotechnical and geophysical approaches and compare the advantages of both methods. The geotechnical approach employs Standard Penetration Test (SPT) data from 17 observation points to calculate the Cyclic Stress Ratio (CSR), Cyclic Resistance Ratio (CRR), and Factor of Safety (FS) using deterministic and probabilistic methods. Meanwhile, the geophysical approach utilizes shear wave velocity data (Vs30) from the United States Geological Survey (USGS) to spatially analyze liquefaction potential. The analysis indicates that the NYIA area is classified as having medium soil density, with Vs30 values ranging from 229.342 m/s to 283.965 m/s, and exhibits a high liquefaction susceptibility, with an average probability exceeding 85%, particularly at depths up to 10 meters. Spatial modeling using ArcGIS provides liquefaction risk maps, offering a visual representation of soil vulnerability distribution. This study highlights the advantage of the geotechnical approach in providing specific point-based data, while the geophysical approach is more efficient for analyzing broader areas. This information is crucial for disaster mitigation and infrastructure planning in strategic areas like NYIA.