Three dimensional face stability of a tunnel in weak rock masses subjected to seepage forces

Abstract Reliable prediction of tunnel face stability is a key challenge for tunnel engineering, especially when drilling in highly fractured rock masses under the water table. This work aims to study face stability of a circular tunnel in weak rock masses under the water table based on an advanced three-dimensional (3D) rotational collapse mechanism in the context of the kinematical approach of limit analysis. The fractured rock masses are characterized by the Hoek-Brown failure criterion. A 3D steady-state seepage field obtained numerically is used to interpolate hydraulic heads of the 3D collapse mechanism and seepage force is incorporated into this predicting model by directly considering it as a body force. The results provided by the presented approach are compared with those of numerical calculations, showing a good agreement. The proposed work also provides an improvement with respect to other existing solutions. Thanks to the high computational efficiency of the presented method, four sets of normalized charts are obtained for a tunnel driven in weak rock masses under the water table.

[1]  P. de Buhan,et al.  Face stability of shallow circular tunnels driven under the water table : A numerical analysis , 1999 .

[2]  Daniel Dias,et al.  Rotational failure mechanisms for the face stability analysis of tunnels driven by a pressurized shield , 2011 .

[3]  E. Hoek,et al.  Empirical estimation of rock mass modulus , 2006 .

[4]  Didier Subrin,et al.  Stabilité du front d'un tunnel en milieu frottant : un nouveau mécanisme de rupture 3D , 2002 .

[5]  Georg Anagnostou,et al.  Analysis method and design charts for bolt reinforcement of the tunnel face in cohesive-frictional soils , 2015 .

[6]  E. T. Brown,et al.  EMPIRICAL STRENGTH CRITERION FOR ROCK MASSES , 1980 .

[7]  D. Dias,et al.  The effect of pore water pressure on tunnel face stability , 2016 .

[8]  S. Zuo,et al.  Similarity Solution for the Synchronous Grouting of Shield Tunnel Under the Vertical Non-Axisymmetric Displacement Boundary Condition , 2017 .

[9]  P. Egger,et al.  The effect of water seepage forces on the face stability of an experimental microtunnel , 1993 .

[10]  Evert Hoek,et al.  HOEK-BROWN FAILURE CRITERION - 2002 EDITION , 2002 .

[11]  Ansgar Kirsch,et al.  EXPERIMENTAL INVESTIGATION OF FACE STABILITY OF SHALLOW TUNNELS IN , 2009 .

[12]  Xiao‐Li Yang,et al.  Three-Dimensional Stability of Two-Stage Slope in Inhomogeneous Soils , 2017 .

[13]  Fu Huang,et al.  Three-dimensional failure mechanism of a rectangular cavity in a Hoek–Brown rock medium , 2013 .

[14]  Qiujing Pan,et al.  Upper-bound analysis on the face stability of a non-circular tunnel , 2017 .

[15]  Salvador Senent,et al.  Tunnel face stability in heavily fractured rock masses that follow the Hoek–Brown failure criterion , 2013 .

[16]  Daniel Dias,et al.  Three-dimensional face stability analysis of pressurized tunnels driven in a multilayered purely frictional medium , 2015 .

[17]  Daniel Dias,et al.  Stabilisation of the Excavation Face in Shallow Tunnels Using Fibreglass Dowels , 2012, Rock Mechanics and Rock Engineering.

[18]  Wout Broere,et al.  On the face support of microtunnelling TBMs , 2015 .

[19]  Riccardo Castellanza,et al.  Development and validation of a 3D numerical model for TBM–EPB mechanised excavations , 2012 .

[20]  Georg Anagnostou.  The influence of tunnel excavation on the hydraulic head , 1995 .

[21]  Adam Bezuijen,et al.  Pore pressures in front of tunnel, measurements, calculations and consequences for stability of tunnel face , 2006, Modern Tunneling Science and Technology.

[22]  S. Nam,et al.  Effect of seepage forces on tunnel face stability , 2003 .

[23]  C. Christopoulos,et al.  Limit analysis slope stability with nonlinear yield condition , 1988 .

[24]  Wai-Fah Chen.  Limit Analysis and Soil Plasticity , 1975 .

[25]  E. Leca,et al.  Upper and lower bound solutions for the face stability of shallow circular tunnels in frictional material , 1990 .

[26]  Samir Maghous,et al.  Pseudo‐static analysis of tunnel face stability using the generalized Hoek–Brown strength criterion , 2013 .

[27]  Andrei V. Lyamin,et al.  Stability charts for rock slopes based on the Hoek-Brown failure criterion , 2008 .

[28]  D. Dias,et al.  Probabilistic Stability Analysis of a Three-Dimensional Rock Slope Characterized by the Hoek-Brown Failure Criterion , 2017, J. Comput. Civ. Eng..

[29]  Daniel Dias,et al.  Continuous velocity fields for collapse and blowout of a pressurized tunnel face in purely cohesive soil , 2013 .

[30]  Wout Broere,et al.  Influence of Infiltration and Groundwater Flow on Tunnel Face Stability , 2000 .

[31]  Scott W. Sloan,et al.  Limit analysis solutions for the bearing capacity of rock masses using the generalised Hoek–Brown criterion , 2006 .

[32]  Wang Yan,et al.  Slope stability analyses for materials with a non-linear failure envelope , 1988 .

[33]  Daniel Dias,et al.  Probabilistic analyses of tunneling-induced ground movements , 2013 .

[34]  Georg Anagnostou,et al.  Tunnel face stability under seepage flow conditions , 2014 .

[35]  J. Yin,et al.  Seismic and static stability analysis for rock slopes by a kinematical approach , 2004 .

[37]  Hideto Mashimo,et al.  CENTRIFUGE MODEL TEST OF TUNNEL FACE REINFORCEMENT BY BOLTING , 2003 .

[38]  In Mo Lee,et al.  The study of seepage forces acting on the tunnel lining and tunnel face in shallow tunnels , 2001 .

[39]  Pieter A. Vermeer,et al.  Tunnel Heading Stability in Drained Ground , 2002 .

[40]  Q. Pan,et al.  Three dimensional seismic and static stability of rock slopes , 2015 .

[41]  Evert Hoek,et al.  Practical estimates of rock mass strength , 1997 .

[42]  R. Baker,et al.  Upper bound limit analysis of soil with non-linear failure criterion. , 1983 .

[43]  W. F. Chen,et al.  Stability analysis of slopes with general nonlinear failure criterion , 1987 .

[44]  Abdul-Hamid Soubra,et al.  Face Stability Analysis of Circular Tunnels Driven by a Pressurized Shield , 2010 .

[45]  Georg Anagnostou,et al.  Face stability conditions with earth-pressure-balanced shields , 1996 .