Subway Ground-Subsidence Warning System Put to the Test by South Korean Engineers

Satellites, Laser Scanners, and Ground Radar

According to НВ — Техно: Ground subsidence is a serious hazard for metro networks, and early detection is key to avoiding accidents. The MSRS complex, built by engineers at Seoul National University of Science and Technology, is a three-tier monitoring system that pairs satellite radio signals, surface laser scanning, and underground radar. Satellites send radio waves to the ground and compare reflected signals over time to reveal geological changes; laser scans recorded cracks and deformation in a shaft ceiling, while radar detected dangerous voids below a roadway.

Putting MSRS to the Test

On a 16-kilometer section of Seoul's Bundang metro line, the system flagged a 15-mm subsidence near a ventilation shaft, plus cracks and voids under the road. According to study lead Tae-yong Park, the combined approach can characterize construction flaws, settlement, or poor soil compaction in a way that no single technology could.

'Our approach enables detailed characterization of construction defects, subsidence, or insufficient soil compaction, which no individual technology could achieve,' said Park.

Deploying MSRS in Seoul could provide a model for safeguarding subway and underground infrastructure worldwide. As subsidence risks increase with urbanization and climate shifts, such monitoring could lower the likelihood of catastrophic failures and influence how future underground systems are designed and maintained.

Park added: 'Our work aims to shift urban disaster management from reactive emergency response to early prevention, shielding underground tunnels from sudden collapse.'