Stability (learning theory)

Physics

Geology

Finite element method

Sociology

Mathematics

Social science

Mechanics

Petrology

Structural engineering

Quantum tunnelling

Optics

Shield

Machine learning

Limit (mathematics)

Engineering

Mathematical analysis

Composite material

Geotechnical engineering

Materials science

Range (aeronautics)

Geometry

Limit analysis

Face (sociological concept)

Computer science

Anisotropy

Optoelectronics

International Journal of Geomechanics

Shield tunnels are widely used in urban underground construction. The stability of the tunnel face has become a crucial issue in shield tunneling. In this paper, the anisotropy of friction angles is taken into account in the upper theorem of limit analysis of the tunnel face. A formula of the anisotropic friction angles is established and applied in the limit analysis of the tunnel face, and the anisotropic parameters can be determined by the simple triaxial compression tests. The results are compared with existing works to validate the reasonability of the proposed method. Two types of constant friction angles are adopted to compare the anisotropic effects on the support pressures distributed uniformly on the tunnel face and the failure mechanism. The results show that the anisotropy of friction angles will lead to an increase in the support pressures and obviously influence the shape and range of the failure pattern. The anisotropy of friction angles should be considered in the stability analysis of the tunnel face.

Face Stability Analysis for a Shield Tunnel in Anisotropic Sands