Simulation of Shield Tunneling Behavior along a Curved Alignment in a Multilayered Ground

Abstract

The kinematic shield model has been proposed to simulate shield behavior during excavation based on equilibrium condition, taking into account ground displacement around the shield. The model has been validated by the simulation of an earth pressure balanced shield behavior in a straight alignment for a single ground layer. To verify the model performance for shield tunnel excavation at curved alignment in multilayered ground, the slurry shield behavior is simulated in this study using the in situ data, and the immediate ground movements around the shield are computed by three-dimensional FEM employing the enforced displacement, which is obtained from the shield behavior simulation. As a result, it is found that the simulated shield behavior and the computed immediate ground movements around the shield during shield tunneling are in good agreement with the observations. Furthermore, the results reveal that the excavated area including the area generated by copy cutter is a predominant factor affecting the shield behavior, and the ground displacement, at the excavated surface plays an important role in the surrounding ground movements during shield tunneling.