Abstract This study addresses the construction challenges and safety risks associated with the shield launching beneath an existing metro station in the water-rich silty fine sand strata of the Yangtze River′s first terrace. The key risks include water and sand inrush at the tunnel portal, deformation of the existing metro track bed, difficulty in establishing earth pressure balance in the excavation chamber, and continuous grinding of diaphragm walls. This paper systematically presents the adopted engineering countermeasures. Statistical analysis of six key excavation parameters lincluding earth chamber pressure, cutterhead torque, cutterhead rotation speed, penetration rate, advance speed, and total thrust reveals the characteristic variations during shield launching beneath the existing station. In addition, abnormal excavation conditions, glass fiber rebar cutting, and track bed deformation are thoroughly analyzed. The findings provide valuable technical guidance for similar underground crossing projects under complex geological conditions.
Abstract：
This study addresses the construction challenges and safety risks associated with the shield launching beneath an existing metro station in the water-rich silty fine sand strata of the Yangtze River′s first terrace. The key risks include water and sand inrush at the tunnel portal, deformation of the existing metro track bed, difficulty in establishing earth pressure balance in the excavation chamber, and continuous grinding of diaphragm walls. This paper systematically presents the adopted engineering countermeasures. Statistical analysis of six key excavation parameters lincluding earth chamber pressure, cutterhead torque, cutterhead rotation speed, penetration rate, advance speed, and total thrust reveals the characteristic variations during shield launching beneath the existing station. In addition, abnormal excavation conditions, glass fiber rebar cutting, and track bed deformation are thoroughly analyzed. The findings provide valuable technical guidance for similar underground crossing projects under complex geological conditions.
CHEN Yunyao
.Risk Mitigation Measures and Excavation Analysis of Shield Launching beneath an Existing Metro Station on the First Terrace of the Yangtze River[J] MODERN TUNNELLING TECHNOLOGY, 2025,V62(3): 249-258
2025, Vol. 62 