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Shallow tunnel face stability analysis using finite elements

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Category: Content №1 2021

Last Updated on 05 March 2021

Published on 30 November -0001

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Authors:

I.Kahoul, Badji Mokhtar University, Annaba, Algeria, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

S.Yahyaoui, National Polytechnic School, Algiers, Algeria

Y.Mehidi, Larbi Tebessi University, Tebessa, Algeria

Y.Khadri, Badji Mokhtar University, Annaba, Algeria, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

повний текст / full article

Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu. 2021, (1): 091 - 097

https://doi.org/10.33271/nvngu/2021-1/091

Abstract:

Purpose. This work aims to study the tunnel face stability (Algiers subway Tunnel) and evaluate common numerical procedures that are used for analyzing the tunnel face stability. Two-dimensional (2D) and three-dimensional (3D) Finite Element (FE) modeling using PLAXIS programs.

Methodology. Tunneling is executed by the NATM method; two types of calculations are used. The first one is done by reducing the applied face pressure until the face is collapsed. The second calculation method involves the Phi-c (the angle of internal friction and bonding) reduction method, which is based on calculating the safety factor of the shear strength of the soil. Both methods are applied for 2D and 3D FE-modelling.

Findings. It is found that determining the applied face pressure is an important consideration to avoid face failure or excessive deformations with numerical methods resulting in more precise findings than analytical methods.

Originality. The originality of this work is the use of both 2D and 3D modelling, combined with two approaches: structural analysis of plastic state and Phi-c reduction method based on calculating the safety factor of the shear strength of the soil.

Practical value. This study illustrates that the reducing shear strength method is much better than the reducing applied face pressure method. Moreover, the result of 3D FE-modelling gives a better prediction comparing with the 2D FE-modelling results.

Keywords: tunnel, numerical modelling, tunnel face stability, Plaxis 2D, Plaxis 3D tunnel, Algiers subway tunnel

References.

1. Elmanan, A.M.A., & Elarabi, H. (2016). Analytical and numerical analysis for tunnel heading stability. Conference paper: The Seventh Graduate Studies and Scientific Research Conference, Khartoum, Sudan. Retrieved from https://www.researchgate.net/publication/299377004_ANALYTICAL_AND_NUMERICAL_ANALYSIS_FOR_TUNNEL_HEADING_STABILITY.

2. Ahmed, S.N.A., & David, N.C. (2019). Numerical modelling of tunnel face stability in homogeneous and layered soft ground. Tunnelling and Underground Space Technology, 94. https://doi.org/10.1016/j.tust.2019.103096.

3. Riaz, A., Jamil, S.M., Asif, M., & Akhtar, K. (2016). Tunnel support design by comparison of empirical and finite element analysis of the Nahakki tunnel in Mohmand agency, Pakistan. Studia Geotechnica et Mechanica, 38, 75-84. https://doi.org/10.1515/sgem-2016-0008.

4. Zizka, Z., Kube, S., Scher, B., & Thewes, M. (2020). Influence of stagnation gradient for face support calculation in Slurry Shield Tunnelling. Geomechanics and Tunnelling, 13, 372-381. https://doi:10.1002/geot.202000009.

5. Leca, E., & Dormieux, L. (2015). Upper and lower bound solutions for the face stability of shallow circular tunnels in frictional material. Gotechnique, 40(4), 58-606. https://doi.org/10.1680/geot.1990.40.4.581.

6. Li, L., Zheng, W., & Wang, Y. (2018). Prediction of Moment Redistribution in Statically Indeterminate Reinforced Concrete Structures Using Artificial Neural Network and Support Vector Regression. Applied Sciences, 9(28). https://doi.org/10.3390/app9010028.

7. Fu, Y., & Zheng, H. (2017). Numerical Research on Face Stability of Pipe Jacking Tunnel in Soft Clay. Chinese Journal of Underground Space and Engineering. Retrieved from https://en.cnki.com.cn/Article_en/CJFDTotal-BASE2017S2020.htm.

8. Padua-Fernndez, R., Rivera-Constantino, R., & Marengo-Mogolln, H. (2011). Diseo geotcnico del tnel de desfogue del proyecto hidroelctrico La Yesca, Mxico. Conference proceedings, Pan-Am CGS Geotechnical Conference: 64^th Canadian Geotechnical Conference and 14^th Pan-American Conference on Soil Mechanics and Geotechnical Engineering, Toronto, Ontario, Canada. Retrieved from https://docplayer.es/21790193-Diseno-geotecnico-del-tunel-de-desfogue-del-proyecto-hidroelectrico-la-yesca-mexico.html.

9. Brinkgreve, R.B.J. (Ed.) (2018). PLAXIS 2D Manuals. General Information, Tutorial Manual, Reference Manual, Material Models Manual, Scientific Manual. Delft University of Technology & PLAXIS. ISBN-13: 978-90-76016-24-5. Retrieved from www.plaxis.com.

10. Smith, I.M., Griffiths, D.V., & Margetts, L. (2014). Programming the finite element method (5^th ed.). Chichester: John Wiley & Sons Ltd. Retrieved from https://books.google.dz/books?id=ZbtiAAAAQBAJ&printsec=frontcover&hl=fr.

11. Barla, G. (2016). Full-face excavation of large tunnels in difficult conditions. Journal of Rock Mechanics and Geotechnical Engineering, 8, 294-303. https://doi.org/10.1016/j.jrmge.2015.12.003.

12. Janin, J.-P. (2012). Tunnels en milieu urbain: Prvisions des tassements avec prise en compte des effets des pr-soutnements (renforcement du front de taille et vote-parapluie). INSA de Lyon, France. Retrieved from http://theses.insa-lyon.fr/publication/2012ISAL0038/these.pdf.

13. Elmanan, A.M. (2016). Elementary and Finite Element Methods for Analysis of Closed Face Tunnels (Unpublished masters thesis). University of Khartoum Suden. Retrieved from http://onlinejournals.uofk.edu/index.php/JBRR/article/view/1463/1476.

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