Subsurface Layer Mapping in a Land Subsidence Prone Area using Ground Penetrating Radar (GPR) Method: A Case Study in Gelora Bandung Lautan Api Stadium, Bandung, Indonesia

Abstract

Gedebage District indicates land subsidence, particularly in low-lying areas underlain by alluvial deposits. These geological conditions contribute to an increase in land subsidence susceptibility. One of the most critically affected areas is Gelora Bandung Lautan Api (GBLA) Stadium in Gedebage District. This vulnerability is indicated by surface manifestations such as cracking, localized ground collapse, and land subsidence reaching up to 40 cm around the stadium. This study investigates subsurface conditions in the vicinity of the GBLA Stadium using Ground Penetrating Radar (GPR) as a non-invasive geophysical method. Data was collected along five survey lines using 400 MHz and 40 MHz antennas and processed using MATGPR software. The resulting GPR profiles reveal a layered subsurface structure based on amplitude response contrasts, obtained through a processing step involving noise reduction and signal enhancement. GPR interpretation at 400 MHz and 40 MHz shows similar subsurface patterns at depths of 4 meters (high frequency) and 12 meters (low frequency), with clearer layer boundaries at 400 MHz. Borehole data guided the interpretation and confirmed that the subsurface is dominated by soft to very soft clay and silty soils with high plasticity. Radargrams indicate moist to dense clay, suggesting ongoing consolidation and significant subsidence risk. The results of this study are expected to serve as a reference for risk mitigation in the planning and management of GBLA Stadium development.