12.5m EPB TBM Completes 6.8km Undersea Metro Shaft Tunneling

Excavating through complex clay and high-water content silt deposits, the 12.5-meter Earth Pressure Balance (EPB) TBM has successfully broken through into the central metro station. Utilizing automated soil conditioning with foam injection and real-time PLC earth pressure regulation, ground settlement was controlled within ±2mm throughout the 6.8km drive.