ScholarWorks@성균관대학교

초록

Railway infrastructure forms the backbone of global transportation networks, supporting economic and societal development. However, structural deformations in railway systems can hinder the effectiveness of the network, causing speed restrictions or even temporary shutdowns. In South Korea, ground subsidence along the railway tracks has recently become a significant concern. Thus, regular monitoring of railway track structural health is critical for safety, efficiency, hazard prevention, and protection of lives and assets. To address these challenges, we propose an integrated approach for monitoring vertical displacement (VD) along railway tracks in the Wonju region, South Korea, using the conventional Differential Interferometric Synthetic Aperture Radar (DInSAR) technique and the Geographic Information System (GIS). A total of 18 ascending-orbit Sentinel-1 SLC data (2017-2022) were processed using the SNAP toolbox to generate 17 interferometric pairs. Consequently, stable pixels (coherence >= 0.4) were used for VD time series analysis. The findings indicate that certain railway segments are unstable, with the vertical displacement rate (VDR) ranging from -10.60 to 11.54 mm/yr. Approximately 42.04% of stable pixels along the railway corridor exhibit varying degrees of subsidence. Notable settlement trends were observed at Manjong (-4.20 mm/yr), Samsan (-2.19 mm/yr), and Wonju (-0.39 mm/yr) stations, while Seowonju exhibits high temporal variability. Correlation analyses with subsurface lithology, effective shear wave velocity (Vs30), and groundwater trends indicate that deformation patterns are spatially associated with thick unconsolidated alluvial deposits, seismic site classes D and C (Vs30 257-696 m/sec), and localized aquifer drawdown. Groundwater near Manjong shows a long-term decline (-0.02 m/yr), aligning with observed predominance subsidence, while a slight rise near Wonju (0.08 m/yr) suggests secondary consolidation. This finding highlights the combined influence of hydrogeological and geotechnical factors on track stability. The results demonstrate the effectiveness of the proposed integrated conventional DInSAR-GIS approach for cost-efficient infrastructure monitoring. The resulting VDR database can support data-driven maintenance planning, land-use regulation, and long-term resilience of railway systems.

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