Explicit analysis for the ground response behavior due to the advanced excavation of tunnel under anisotropic stress field

Abstract

The purpose of this research is that the analytical solutions of nonlinear behaviour of ground in a deep circular tunnel under anisotropic stress field are derived, and the explicit analysis method (EAM) which bases on the convergence confinement method, the principle of convergence loss, and the simple calculation spreadsheet is particularly proposed. This study includes that introducing a incremental procedure of confinement loss into the analytical solutions derived under anisotropic stress field, establishing the direct calculation logic and flow chart, using a calculation spreadsheet to simply calculate and draw figures, considering the stress path and ground response curve at excavation face, and distribution of stress/displacement around tunnel. The results obtained by the explicit analysis and by the finite element analysis are approximately consistent in those curves described in the convergence-confinement method. The explicit analysis method proposed is easy and directly to simulate the ground response behaviour due to the advanced excavation of tunnel.