Numerical simulation analysis of the influence of shield tunneling on an adjacent tunnel

In the case of a shield tunnel construction in Beijing, on the basis of the interaction mechanism of neighborhood tunnels during tunnel excavating, a 3D nonlinear numerical simulation model was set up. The developing laws of the segment lining stress, ground deformation around tunnels, segment lining deformation, and changing bending moment of segment lining in different tunnel spaces are analyzed in detail. The results show that the stress growth rate of segment lining and tunnel space are linearly descending related to the situation of the immediately adjacent shielding. The ground settlement form is similar to the case of the single-tunnel construction due to space constraint. Furthermore, it is found that the form is single mode. Under horizontal compression and vertical tension, the segment lining deformation is in ellipse deformation trend. The response of the left existing tunnel to adjacent shielding has hysteresis effect. The result shows that 3D numerical model is a useful method, which can directly display the interaction law of neighborhood tunnels during construction. The study results can be used to guide the construction of immediately adjacent shield tunnels.