Optimization Design for Support Pressure of Shield Tunnel Face to Predict the Ground Disturbance Induced by Shield Excavation

The support pressure at a shield tunnel face is significant for the stability of the shield excavation and prediction of ground disturbance. This study presents an optimization measure that relies on the three-dimensional (3D) limit equilibrium method (LEM) to determine the reasonable support pressure of the shield tunnel face. The predetermined support pressure is subsequently incorporated into the finite-element (FE) model, and the ground disturbance that is induced by the shield excavation could be estimated by the FE simulation. The face support pressure that is obtained from the optimization measure aligns remarkably well with those derived from other methodologies, therefore confirming its efficacy. Furthermore, the numerical results demonstrate that the support pressure, as determined by the optimization measure, provides superior control on the ground disturbance. To further estimate the sensitivity of the tunnel buried depth and soil strength in relation to the ground disturbance, orthogonal testing is conducted. The outcomes of this orthogonal testing inform the development of a predictive approach for evaluating ground disturbances that are caused by the shield excavation, which is then validated by comparing it with previous works. The findings of this study serve as a valuable asset in facilitating the rapid prediction of ground disturbance that is induced by shield excavation.