Prediction of Land Subsidence in the Bandung Basin Through Integrated CPTu Data Analysis for Geohazard Mitigation

Abstract Land subsidence is a geological phenomenon characterized by the gradual lowering of the land surface due to the movement or compaction of subsurface materials. With the increasing population and industrial growth driven by its designation as a National Strategic Area, the Bandung Basin has become more susceptible to natural disasters, including land subsidence. Measurements using the Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) indicate that the Bandung Basin is experiencing ground subsidence at 8 cm to 23 cm per year. To reveal subsurface conditions, we conducted site investigations using Cone Penetration Tests with pore pressure measurement (CPTu) at representative locations. This study involved 12 CPTu points with depths ranging from 6 to 47 meters. Interpretation of Soil Behavior Type (SBT) was conducted from the CPTu data to determine the subsurface lithology of the Bandung Basin. The correlation of CPTu data indicates that the subsurface layers of the Bandung Basin, up to a depth of 40 meters, consist of thick, compressive clay lithology, which poses a significant risk of land subsidence. This research aims to predict land subsidence due to natural consolidation factors using subsurface profiles based on CPTu data. The land subsidence analysis method employed is the one-dimensional consolidation method. The analysis results indicate that the potential for land subsidence ranges from 0.05 to 0.46 meters over a maximum period of 1.35 to 224.9 years. These predictions are expected to provide accurate and effective guidelines for mitigation efforts.