Risk Analysis of Subway Shield Tunneling

Shield tunneling technology is widely used in modern subway systems for construction due to its construction speed and accessibility in urban areas with congested ground traffic. However, non-uniform ground settlement caused by excavation activities can damage adjacent structures, which raises concerns regarding the safety and risk of shield tunneling construction methods. To evaluate its impact, this research investigates an approach to establish criteria for risk analysis in shield tunneling construction. Three-dimensional numerical modeling is performed using representative conditions. Soil stabilization at the cut face, earth pressure equilibrium during shoving, and the strength of the concrete outer layer were all found to be issues of concern for shield tunneling. Disturbance of in-situ soil and reconsolidation due to varying pore pressure are identified as tunneling-induced factors that may trigger ground subsidence. Finally, risk control measures are recommended based on the results of the investigation.