Improved Analytical Solution for Ground Movements Induced by Circular Tunnel Excavation Based on Ground Loss Correction

This paper presents an improved analytical solution for the prediction of ground movements based on the ground loss correction. The boundary function of ground displacement composed of radial contraction, vertical translation of tunnel and tunnel ovalization is derived. The displacement analytical solution is further optimized by the equivalent ground loss rate components corrected from both the vertical translation of the tunnel and the geological conditions. Field measurements from eight tunnel cases are used to validate the capability and applicability of the proposed solution. Finally, the influence of the three deformation components mentioned above on ground deformation is explored. The results demonstrate that in practice, while the focus is on the quality and timing of grouting to control ground loss, the vertical translation of the tunnel should also be strictly controlled. The research results in this paper can provide a new simple and reliable calculation method for predicting the ground movements induced by circular tunnel excavation.