Influence of the Cutterhead Configuration and Operation Parameters on the Face Stability of EPB Shield Tunnels in Dry Granular Soils
Publication: International Journal of Geomechanics
Volume 21, Issue 5
Abstract
This paper presents a study on the face stability of earth pressure balance (EPB) shield tunnels in dry granular soils using the discrete element model (DEM) method to replicate realistic excavation processes of the EPB machine. Analyses were conducted at different buried depths to determine the limit face pressures and the face failure model induced by the EPB shield machine with varying open ratios and rotation speeds of the cutterhead. The failure kinematics of the soil and the soil arching effect were also determined. The results showed that both the open ratio and the rotation speed of the cutterhead have significant effects on the stability of the face in terms of the failure kinematics, limit face pressures, and the soil arching effect. The failure zone was highly dependent on the open ratio, but it depended less on the rotation speed of the cutterhead. The stability of the face is overestimated when the excavation is conducted with a cutterhead that has a large open ratio, but it is underestimated when the excavation is conducted with a cutterhead that has a smaller open ratio. Ignoring the effect of the configuration of the cutterhead and the rotation speed results in unexpected and unrealistic results.
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Acknowledgments
This research was supported by the National Key Research and Development Program (2016YFC0802205) and the National Science Foundation of China (No 51578460).
Notation
The following symbols are used in this paper:
- Bh
- height of the arch above the crown of the tunnel;
- C
- overburden;
- Cs
- calculation step;
- CS
- rotation speed of the screw conveyor;
- c
- cohesion force;
- D
- diameter of the tunnel;
- DS
- diameter of the shield;
- DS
- driving speed of shield machine;
- D50
- mean particle size;
- d
- diameter of particles;
- fball-ball
- friction coefficient between particle and particle;
- fb-container
- friction coefficient between particle and container;
- fb-EPB
- friction coefficient between particle and EPB machine;
- H
- distance from the bottom of chamber;
- H
- height of the chimney;
- Ha
- extended height of the arch;
- h
- distance from wedge bottom to tunnel invert;
- kn
- normal stiffness coefficient of particles;
- ks
- tangential stiffness coefficient of particles;
- Ls
- length of the shield machine;
- Lsc
- length of the screw conveyor;
- OR
- open ratio of the cutterhead;
- P
- support pressure at the face;
- Pchamber
- soil pressure in the chamber;
- Pf
- limit support pressure at the face;
- Pv
- porosity variation of the soil;
- PC
- pitch of the screw conveyor;
- P0
- initial stress at the specified buried depth;
- RS
- rotation speed of the cutterhead;
- Smax
- maximum displacement of particles;
- ud
- damping coefficient;
- ur
- rolling resistance coefficient;
- β
- inclination angle of the wedge;
- ɛa
- axial strain of the soil;
- σ
- stress of soil in the normal direction;
- σyy
- horizontal stress of the ground;
- σ1
- major principal stress of the soil;
- σ3
- minor principal stress of the soil;
- τ
- shear stress of the soil; and
- φ
- friction angle of the soil.
References
Ahmed, M., and M. Iskander. 2012. “Evaluation of tunnel face stability by transparent soil models.” Tunnelling Underground Space Technol. 27 (1): 101–110. https://doi.org/10.1016/j.tust.2011.08.001.
Alagha, A. S. N., and D. N. Chapman. 2019. “Numerical modelling of tunnel face stability in homogeneous and layered soft ground.” Tunnelling Underground Space Technol. 94: 103096. https://doi.org/10.1016/j.tust.2019.103096.
Anagnostou, G. 2012. “The contribution of horizontal arching to tunnel face stability.” Geotechnik 35 (1): 34–44. https://doi.org/10.1002/gete.201100024.
Anagnostou, G., and K. Kovári. 1994. “The face stability of slurry-shield-driven tunnels.” Tunnelling Underground Space Technol. 9 (2): 165–174. https://doi.org/10.1016/0886-7798(94)90028-0.
ASTM. 2011. Method for consolidated drained triaxial compression test for soils. ASTM D7181-11. West Conshohocken, PA: ASTM.
Atkinson, J. H., and D. M. Potts. 1977. “Stability of a shallow circular tunnel in cohesionless soil.” Géotechnique 27 (2): 203–215. https://doi.org/10.1680/geot.1977.27.2.203.
Berthoz, N., D. Branque, D. Subrin, H. Wong, and E. Humbert. 2012. “Face failure in homogeneous and stratified soft ground: Theoretical and experimental approaches on 1g EPBS reduced scale model.” Tunnelling Underground Space Technol. 30: 25–37. https://doi.org/10.1016/j.tust.2012.01.005.
Berthoz, N., D. Branque, H. Wong, and D. Subrin. 2018. “TBM soft ground interaction: Experimental study on a 1g reduced-scale EPBS model.” Tunnelling Underground Space Technol. 72: 189–209. https://doi.org/10.1016/j.tust.2017.11.022.
Broere, W. 2001. “Tunnel face stability and new CPT applications.” Ph.D. thesis, Dept. of Engineering, Delft Univ. of Technology.
Chambon, P., and J. F. Corte. 1994. “Shallow tunnels in cohesionless soil: Stability of tunnel face.” J. Geotech. Eng. 120 (7): 1148–1165. https://doi.org/10.1061/(ASCE)0733-9410(1994)120:7(1148).
Chen, R. P., J. Li, L. G. Kong, and L. J. Tang. 2013. “Experimental study on face instability of shield tunnel in sand.” Tunnelling Underground Space Technol. 33: 12–21. https://doi.org/10.1016/j.tust.2012.08.001.
Chen, R. P., L. J. Tang, D. S. Ling, and Y. M. Chen. 2011. “Face stability analysis of shallow shield tunnels in dry sandy ground using the discrete element method.” Comput. Geotech. 38 (2): 187–195. https://doi.org/10.1016/j.compgeo.2010.11.003.
Chen, R. P., X. Yin, L. Tang, and Y. Chen. 2018. “Centrifugal model tests on face failure of earth pressure balance shield induced by steady state seepage in saturated sandy silt ground.” Tunnelling Underground Space Technol. 81: 315–325. https://doi.org/10.1016/j.tust.2018.06.031.
De Oliveira, D. G. G. 2018. “EPB excavation and conditioning of cohesive mixed soils: clogging and flow evaluation.” Ph.D. thesis, Dept. of Geological Sciences and Geological Engineering, Queen’s Univ.
Ding, W., K. Liu, P. Shi, M. Li, and M. Hou. 2019. “Face stability analysis of shallow circular tunnels driven by a pressurized shield in purely cohesive soils under undrained conditions.” Comput. Geotech. 107: 110–127. https://doi.org/10.1016/j.compgeo.2018.11.025.
Fakhimi, A., F. Carvalho, T. Ishida, and J. F. Labuz. 2002. “Simulation of failure around a circular opening in rock.” Int. J. Rock Mech. Min. Sci. 39 (4): 507–515. https://doi.org/10.1016/S1365-1609(02)00041-2.
Fellin, W., J. King, A. Kirsch, and M. Oberguggenberger. 2010. “Uncertainty modelling and sensitivity analysis of tunnel face stability.” Struct. Saf. 32 (6): 402–410. https://doi.org/10.1016/j.strusafe.2010.06.001.
Hu, X., C. He, X. Lai, G. Walton, W. Fu, and Y. Fang. 2020a. “A DEM-based study of the disturbance in dry sandy ground caused by EPB shield tunneling.” Tunnelling Underground Space Technol. 101: 103410. https://doi.org/10.1016/j.tust.2020.103410.
Hu, X., C. He, Z. Peng, and W. Yang. 2019. “Analysis of ground settlement induced by earth pressure balance shield tunneling in sandy soils with different water contents.” Sustainable Cities Soc. 45: 296–306. https://doi.org/10.1016/j.scs.2018.10.038.
Hu, X., C. He, G. Walton, Y. Fang, and G. Dai. 2020b. “Laboratory model test of EPB shield tunneling in a cobble-rich soil.” J. Geotech. Geoenviron. Eng. 146 (10): 04020112. https://doi.org/10.1061/(ASCE)GT.1943-5606.0002355.
Hu, X., W. Fu, J. W. Ju, C. He, Y. Fang, and J. Wang. 2021. “Face stability conditions in granular soils during the advancing and stopping of earth-pressure-balanced-shield machine.” Tunn. Undergr. Space Technol. 109: 103755. https://doi.org/10.1016/j.tust.2020.103755.
Ibrahim, E., A. H. Soubra, G. Mollon, W. Raphael, D. Dias, and A. Reda. 2015. “Three-dimensional face stability analysis of pressurized tunnels driven in a multilayered purely frictional medium.” Tunnelling Underground Space Technol. 49: 18–34. https://doi.org/10.1016/j.tust.2015.04.001.
Idinger, G., P. Aklik, W. Wu, and R. I. Borja. 2011. “Centrifuge model test on the face stability of shallow tunnel.” Acta Geotech. 6 (2): 105–117. https://doi.org/10.1007/s11440-011-0139-2.
Itasca. 2008. Particle flow code in 3 dimensions (PFC3D) user’s guide. Minneapolis, MN: Itasca Consulting Group.
Iwashita, K., and M. Oda. 1998. “Rolling resistance at contacts in simulation of shear band development by DEM.” J. Eng. Mech. 124 (3): 285–292. https://doi.org/10.1061/(ASCE)0733-9399(1998)124:3(285).
Jiang, M., S. Leroueil, H. Zhu, H. S. Yu, and J. M. Konrad. 2009. “Two-dimensional discrete element theory for rough particles.” Int. J. Geomech. 9 (1): 20–33. https://doi.org/10.1061/(ASCE)1532-3641(2009)9:1(20).
Karim, A. M. 2007. “Three-dimensional discrete element modeling of tunneling in sand.” Ph.D. thesis, Dept. of Engineering, Alberta Univ.
Khosravi, A., A. Martinez, and J. T. DeJong. 2020. “DEM simulations of CPT measurements and soil classification.” Can. Geotech. J. 57 (9): 1369–1387. https://doi.org/10.1139/cgj-2019-0512.
Kirsch, A. 2010. “Experimental investigation of the face stability of shallow tunnels in sand.” Acta Geotech. 5 (1): 43–62. https://doi.org/10.1007/s11440-010-0110-7.
Leca, E., and L. Dormieux. 1990. “Upper and lower bound solutions for the face stability of shallow circular tunnels in frictional material.” Géotechnique 40 (4): 581–606. https://doi.org/10.1680/geot.1990.40.4.581.
Lee, I. M., S. W. Nam, and J. H. Ahn. 2003. “Effect of seepage forces on tunnel face stability.” Can. Geotech. J. 40 (2): 342–350. https://doi.org/10.1139/t02-120.
Li, P., F. Wang, C. Zhang, and Z. Li. 2019. “Face stability analysis of a shallow tunnel in the saturated and multilayered soils in short-term condition.” Comput. Geotech. 107: 25–35. https://doi.org/10.1016/j.compgeo.2018.11.011.
Lü, X., Y. Zhou, M. Huang, and S. Zeng. 2018. “Experimental study of the face stability of shield tunnel in sands under seepage condition.” Tunnelling Underground Space Technol. 74: 195–205. https://doi.org/10.1016/j.tust.2018.01.015.
Mair, R. J. 1978. “Centrifugal modelling of tunnel construction in soft clay.” Ph.D. thesis, Dept. of Engineering, Univ. of Cambridge.
Maynar, M. J., and L. E. Rodríguez. 2005. “Discrete numerical model for analysis of earth pressure balance tunnel excavation.” J. Geotech. Geoenviron. Eng. 131 (10): 1234–1242. https://doi.org/10.1061/(ASCE)1090-0241(2005)131:10(1234).
Mollon, G., D. Dias, and A. H. Soubra. 2010. “Face stability analysis of circular tunnels driven by a pressurized shield.” J. Geotech. Geoenviron. Eng. 136 (1): 215–229. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000194.
Mollon, G., D. Dias, and A. H. Soubra. 2011a. “Rotational failure mechanisms for the face stability analysis of tunnels driven by a pressurized shield.” Int. J. Numer. Anal. Methods Geomech. 35 (12): 1363–1388. https://doi.org/10.1002/nag.962.
Mollon, G., K. K. Phoon, D. Dias, and A. H. Soubra. 2011b. “Validation of a new 2D failure mechanism for the stability analysis of a pressurized tunnel face in a spatially varying sand.” J. Eng. Mech. 137 (1): 8–21. https://doi.org/10.1061/(ASCE)EM.1943-7889.0000196.
Oblozinsky, P., and J. Kuwano. 2004. “Centrifuge experiments on stability of tunnel face.” Slovak J. Civ. Eng. 3: 23–29.
Soranzo, E., R. Tamagnini, and W. Wu. 2015. “Face stability of shallow tunnels in partially saturated soil: Centrifuge testing and numerical analysis.” Géotechnique 65 (6): 454–467. https://doi.org/10.1680/geot.14.P.123.
Sun, X., L. Miao, H. Lin, and T. Tong. 2018. “Soil arch effect analysis of shield tunnel in dry sandy ground.” Int. J. Geomech. 18 (6): 04018057. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001135.
Thewes, M., and W. Burger. 2004. “Clogging risks for TBM drives in clay.” Tunnels Tunnelling Int. 36 (6): 28–31.
Wang, S., T. Qu, Y. Fang, J. Fu, and J. Yang. 2019. “Stress responses associated with earth pressure balance shield tunneling in dry granular ground using the discrete-element method.” Int. J. Geomech. 19 (7): 04019060. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001434.
Wong, K. S., C. W. W. Ng, Y. M. Chen, and X. C. Bian. 2012. “Centrifuge and numerical investigation of passive failure of tunnel face in sand.” Tunnelling Underground Space Technol. 28: 297–303. https://doi.org/10.1016/j.tust.2011.12.004.
Zhang, T., R. N. Taylor, G. Zheng, J. Sun, Q. Fan, Y. Diao, and H. Zhou. 2018. “Modelling ground movements near a pressurised tunnel heading in drained granular soil.” Comput. Geotech. 104: 152–166. https://doi.org/10.1016/j.compgeo.2018.08.015.
Zhang, Z. X., X. Y. Hu, and K. D. Scott. 2011. “A discrete numerical approach for modeling face stability in slurry shield tunnelling in soft soils.” Comput. Geotech. 38 (1): 94–104. https://doi.org/10.1016/j.compgeo.2010.10.011.
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Published In
International Journal of Geomechanics
Volume 21 • Issue 5 • May 2021
Copyright
© 2021 American Society of Civil Engineers.
History
Received: Mar 5, 2020
Accepted: Dec 11, 2020
Published online: Feb 25, 2021
Published in print: May 1, 2021
Discussion open until: Jul 25, 2021
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