Face Stability Analysis of Shield Tunnel Using Slip Line Method

Abstract

The sufficient support pressure is essential to guarantee the safe construction of shield tunnel. Thus, it is necessary to analyze the stability and assess the limit support pressure of the tunnel face. The main methods for face stability analysis mostly focused on finite element method, limit equilibrium method, and numerical simulation method. In this paper, the slip line method is applied to analyze the stability of the tunnel face. The soil is supposed as ideal isotropic, homogeneous, and incompressible continuous material, which obeys the Mohr–Coulomb yield criterion. A mathematical model of the limit equilibrium boundary value problem is established. The slip line method is used to solve the slip line field and stress field of the soil behind the tunnel face. Limit support pressure and failure mechanism of the tunnel face are then obtained. In addition, comparisons between the results of this study and those of existing approach are performed, and the influence factors are also discussed. The results show that the slip line method is proven to be reliable for the evaluation of limit support pressure of the tunnel face stability.

Prediction of the stress-strain state and stability of the front of tunnel face at the intersection of disturbed zones of the soil mass

“…There is an active redistribution of stresses and deformations in the face zone. To assess the stress level, it is proposed to use the strength criterion, the deformation level -the deformation criterion [39]. As a deformation criterion, the stability criterion adopted in engineering practice is taken, expressed in terms of the calculated displacement of the contour of the underground structure.…”