Numerical Study and Field Monitoring of the Ground Deformation Induced by Large Slurry Shield Tunnelling in Sandy Cobble Ground

This paper presents the ground deformation induced by the large slurry shield tunnelling with a diameter of about 12 m in urban areas, which may challenge the safety of the existing nearby constructions and infrastructures. In this study, the ground deformation is analyzed by a three-dimensional finite difference model, involving the simulation of tunnelling advance, grouting, and grouting hardening. The transverse settlement, longitudinal settlement, and horizontal displacement of the ground are analyzed by comparing the simulation results with the field measurements in the Rapid Transit Line Project from Beijing Railway station to West Beijing Railway station in China. The numerical model proposed in this paper could well predict the ground deformation induced by large slurry shield tunnelling. The results show that the main transverse settlement occurs within the zone about 1.5 times of the excavation diameter, and the settlement during the passage of the shield and the tail void plays a most important role in the excavation process