Face Stability Analysis for a Shield Tunnel in Anisotropic Sands

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.

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An improved 3D wedge-prism model for the face stability analysis of the shield tunnel in cohesionless soils

Acta Geotechnica ◽

10.1007/s11440-014-0304-5 ◽

2014 ◽

Vol 10 (5) ◽

pp. 683-692 ◽

Cited By ~ 33

Author(s):

R. P. Chen ◽

L. J. Tang ◽

X. S. Yin ◽

Y. M. Chen ◽

X. C. Bian

Keyword(s):

Stability Analysis ◽

Shield Tunnel ◽

Cohesionless Soils ◽

Face Stability ◽

The Face ◽

Wedge Prism ◽

Prism Model

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Face stability analysis of a shallow horseshoe-shaped shield tunnel in clay with a linearly increasing shear strength with depth

Tunnelling and Underground Space Technology ◽

10.1016/j.tust.2020.103291 ◽

2020 ◽

Vol 97 ◽

pp. 103291 ◽

Cited By ~ 7

Author(s):

Chengping Zhang ◽

Wei Li ◽

Wenjun Zhu ◽

Zhibiao Tan

Keyword(s):

Shear Strength ◽

Stability Analysis ◽

Shield Tunnel ◽

Face Stability

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Analysis of Face Stability during Excavation of Double-O-Tube Shield Tunnel

The Scientific World JOURNAL ◽

10.1155/2013/781968 ◽

2013 ◽

Vol 2013 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Yuyou Yang ◽

Qinghong Zhou ◽

Hongan Li ◽

Xuegang Huang ◽

Xiaoming Tu

Keyword(s):

Stability Analysis ◽

Failure Mechanism ◽

Three Dimensional ◽

Soil Mass ◽

Shield Tunnel ◽

Face Stability ◽

Supporting Pressure ◽

The Face ◽

Collapse Failure ◽

Kinematic Theorem

This paper focuses on the face stability analysis of Double-O-Tube shield tunnel. This kind of analysis is significant to ensure the safety of workers and reduce the influence on the surrounding environment. The key point of the stability analysis is to determine the supporting pressure applied to the face by the shield. A collapse failure will occur when the supporting pressure is not sufficient to prevent the movement of the soil mass towards the tunnel. A three-dimensional collapse failure mechanism was presented in this paper. Based on the mechanism of a single circular shield tunnel, the mechanism of Double-O-Tube shield tunnel was established by using the fact that both of the mechanisms are symmetrical. Then by means of the kinematic theorem of limit analysis, the numerical results were obtained, and a design chart was provided. The finite difference software FLAC3D was applied to investigate the face failure mechanism of DOT shield tunnel established in this paper; the critical supporting pressures of the collapse failure mechanism in different strata (sand and silt) were calculated. Through comparative analysis, the theoretical values were very close to the numerical values. This shows that the face failure mechanism of DOT shield tunnel is reasonable, and it can be applied to the sand and silt strata.

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