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

2014 ◽  
Vol 10 (5) ◽  
pp. 683-692 ◽  
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

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

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
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.

scholarly journals Upper Bound Solution for the Face Stability of Shield Tunnel below the Water Table

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Xilin Lu ◽  
Haoran Wang ◽  
Maosong Huang
Keyword(s):  
Upper Bound ◽  
Limit Analysis ◽  
Fe Simulation ◽  
Shield Tunnel ◽  
Support Pressure ◽  
Seepage Force ◽  
Tunnel Face ◽  
Face Stability ◽  
The Face ◽  
Upper Bound Limit Analysis

By FE simulation with Mohr-Coulomb perfect elastoplasticity model, the relationship between the support pressure and displacement of the shield tunnel face was obtained. According to the plastic strain distribution at collapse state, an appropriate failure mechanism was proposed for upper bound limit analysis, and the formula to calculate the limit support pressure was deduced. The limit support pressure was rearranged to be the summation of soil cohesionc, surcharge loadq, and soil gravityγmultiplied by their corresponding coefficientsNc,Nq, andNγ, and parametric studies were carried out on these coefficients. In order to consider the influence of seepage on the face stability, the pore water pressure distribution and the seepage force on the tunnel face were obtained by FE simulation. After adding the power of seepage force into the equation of the upper bound limit analysis, the total limit support pressure for stabilizing the tunnel face under seepage condition was obtained. The total limit support pressure was shown to increase almost linearly with the water table.

Effect of the seepage flow on the face stability of a shield tunnel

2021 ◽  
Vol 112 ◽  
pp. 103900
Author(s):  
Wei Li ◽  
Chengping Zhang ◽  
Zhibiao Tan ◽  
Mengshuo Ma
Keyword(s):  
Seepage Flow ◽  
Shield Tunnel ◽  
Face Stability ◽  
The Face

An analytical model for face stability of shield tunnel in dry cohesionless soils with different buried depth

2022 ◽  
Vol 142 ◽  
pp. 104565
Author(s):  
Yu Zhang ◽  
Lianjin Tao ◽  
Xu Zhao ◽  
Heng Kong ◽  
Fei Guo ◽  
...  
Keyword(s):  
Analytical Model ◽  
Shield Tunnel ◽  
Cohesionless Soils ◽  
Face Stability

scholarly journals Face Stability Analysis of Shield Tunnel Using Slip Line Method

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Weiping Liu ◽  
Shaofeng Wan ◽  
Xinqiang Song ◽  
Mingfu Fu ◽  
Lina Hu
Keyword(s):  
Stability Analysis ◽  
Slip Line ◽  
Yield Criterion ◽  
Limit Equilibrium ◽  
Shield Tunnel ◽  
Support Pressure ◽  
Tunnel Face ◽  
Face Stability ◽  
Line Method ◽  
The Stability

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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