Geomechanics and Engineering

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

A new formulation for calculation of longitudinal displacement profile (LDP) on the basis of rock mass quality

  • Rooh, Ali (Rock Mechanics Division, School of Engineering, Tarbiat Modares University) ;
  • Nejati, Hamid Reza (Rock Mechanics Division, School of Engineering, Tarbiat Modares University) ;
  • Goshtasbi, Kamran (Rock Mechanics Division, School of Engineering, Tarbiat Modares University)
  • Received : 2018.03.04
  • Accepted : 2018.10.02
  • Published : 2018.12.10
⟨ Previous Next ⟩

Abstract

Longitudinal Displacement Profile (LDP) is an appropriate tool for determination of the displacement magnitude of the tunnel walls as a function of the distance to the tunnel face. Some useful formulations for calculation of LDP have been developed based on the monitoring data on site or by 3D numerical simulations. However, the presented equations are only based on the tunnel dimensions and for different quality of rock masses proposed a unique LDP. In the present study, it is tried to present a new formulation, for calculation of LDP, on the basis of Rock mass quality. For this purpose, a comprehensive numerical simulation program was developed to investigate the effect of rock mass quality on the LDP. Results of the numerical modelling were analyzed and the least square technique was used for fitting an appropriate curve on the derived data from the numerical simulations. The proposed formulation in the present study, is a logistic function and the constants of the logistic function were predicted by rock mass quality index (GSI). Results of this study revealed that, the LDP curves of the tunnel surrounded by rock masses with high quality (GSI>60) match together; because the rock mass deformation varies over an elastic range.

Keywords

References

  1. Alejano, L.R., Rodriguez-Dono, A. and Veiga, M. (2012), "Plastic radii and longitudinal deformation profiles of tunnels excavated in strain-softening rock masses", Tunn. Undergr. Sp. Technol., 30, 169-182. https://doi.org/10.1016/j.tust.2012.02.017
  2. Alejano, L.R., Rodriguez-Dono, A., Alonso, E. and Manin, G.F. (2009), "Ground reaction curves for tunnels excavated in different quality rock masses showing several types of post-failure behaviour", Tunn. Undergr. Sp. Technol., 24(6), 689-705. https://doi.org/10.1016/j.tust.2009.07.004
  3. Aydan, O., Akagi, T. and Kawamoto, T. (1993), "The squeezing potential of rocks around tunnels; theory and prediction", Rock Mech. Rock Eng., 26(2), 137-163. https://doi.org/10.1007/BF01023620
  4. Aydan, O., Ulusay, R. and Tokashiki, N. (2014), "A new rock mass quality rating system: Rock mass quality rating (RMQR) and its application to the estimation of geomechanical characteristics of rock masses", Rock Mech. Rock Eng., 47(4), 1255-1276. https://doi.org/10.1007/s00603-013-0462-z
  5. Carranza-Torres, C. and Fairhurst, C. (2000), "Application of the convergence-confinement method of tunnel design to rock masses that satisfy the Hoek-Brown failure criterion", Tunn. Undergr. Sp. Technol., 15(2), 187-213. https://doi.org/10.1016/S0886-7798(00)00046-8
  6. Chern, J.C., Shiao, F.Y. and Yu, C.W. (1998), "An empirical safety criterion for tunnel construction", Proceedings of the Regional Symposium on Sedimentary Rock Engineering, Taipei, Taiwan, November.
  7. Corbetta, F., Bernaud, D. and Minh, D.N. (1991), "Contribution a la methode convergence confinement par le principe de la similitude", Rev. Franc. Geotech., (54), 5-11.
  8. Ghiasi, V., Ghiasi, S. and Prasad, A. (2012), "Evaluation of tunnels under squeezing rock condition", J. Eng. Des. Technol., 10(2), 168-179. https://doi.org/10.1108/17260531211241167
  9. Hoek, E. (1999), Personal Communication.
  10. Hoek, E. and Brown, E.T. (1997), "Practical estimates of rock mass strength", Int. J. Rock Mech. Min. Sci., 34(8), 1165-1186. https://doi.org/10.1016/S1365-1609(97)80069-X
  11. Hoek, E., Carranza-Torres, C. and Corkum, B. (2002), "Hoek-Brown failure criterion-2002 edition", Proceedings of the 5th North American Rock Mechanics Symposium and the 17th Tunnelling Association of Canada Conference, Toronto, Canada, July.
  12. Itasca Consulting Group (2009), FLAC3D (Fast Lagrangian Analysis of Continua in 3 Dimensions), Version 5.0 Manual. Minneapolis, Minnesota, U.S.A.
  13. Komurlu, E., Kesimal, A. and Hasanpour, R. (2015), "In situ horizontal stress effect on plastic zone around circular underground openings excavated in elastic zones", Geomech. Eng., 8(6), 783-799. https://doi.org/10.12989/gae.2015.8.6.783
  14. Panet, M. (1995), Calcul des Tunnels par la Methode de Convergence-Confinement, Presses de l'Ecole Nationale des Ponts et Chausse'es, Paris, France.
  15. Panet, M. and Guenot, A. (1982), "Analysis of convergence behind the face of a tunnel", Proceedings of the 3rd International Symposium on Tunnelling, Brighton, U.K., June.
  16. Sadeghiyan, R., Hashemi, M. and Moloudi, E. (2016), "Determination of longitudinal convergence profile considering effect of soil strength parameters", Int. J. Rock Mech. Min. Sci., 82, 10-21. https://doi.org/10.1016/j.ijrmms.2015.10.011
  17. Unlu, T. and Gercek, H. (2003), "Effect of Poisson's ratio on the normalized radial displacements occurring around the face of a circular tunnel", Tunn. Undergr. Sp. Technol., 18(5), 547-553 https://doi.org/10.1016/S0886-7798(03)00086-5
  18. Vlachopoulos, N. and Diederichs, M.S. (2009), "Improved longitudinal displacement profiles for convergence confinement analysis of deep tunnels", Rock Mech. Rock Eng., 42(2), 131-146. https://doi.org/10.1007/s00603-009-0176-4