Buy article PDF
The purchased file will be sent to you
via email after the payment is completed.
US$ 35
|
Geomechanics and Engineering Volume 16, Number 3, October30 2018 , pages 295-308 DOI: https://doi.org/10.12989/gae.2018.16.3.295 |
|
|
|
2D numerical investigation of twin tunnels-Influence of excavation phase shift |
||
Chafia Djelloul, Toufik Karech, Rafik Demagh, Oualid Limam and Juan Martinez
|
||
| Abstract | ||
| The excavation of twin tunnels is a process that destabilizes the ground. The stability of the tunnel lining, the control of ground displacements around the tunnel resulting from each excavation and the interaction between them must be controlled. This paper provides a new approach for replacing the costly 3D analyses with the equivalent 2D analyses that closely reflects the in-situ measurements when excavating twin tunnels. The modeling was performed in two dimensions using the FLAC2D finite difference code. The three-dimensional effect of excavation is taken into account through the deconfinement rate l of the soil surrounding the excavation by applying the convergence-confinement method. A comparison between settlements derived by the proposed 2D analysis and the settlements measured in a real project in Algeria shows an acceptable agreement. Also, this paper reports the investigation into the changes in deformations on tunnel linings and surface settlements which may be expected if the twin tunnels of T4 El-Harouche Skikda were constructed with a tunneling machine. Special attention was paid to the influence of the excavation phase shift distance between the two mechanized tunnel faces. It is revealed that the ground movements and the lining deformations during tunnel excavation depend on the distance between the tunnels\' axis and the excavation phase shift. | ||
| Key Words | ||
| tunnel; interaction; numerical-simulation; convergence-confinement; excavation phase shift | ||
| Address | ||
| Chafia Djelloul: 1.) Department of Civil Engineering, Faculty of Technology, Batna 2 University, 53 Street of Constantine, Fésdis, CP 05078 Batna, Algeria 2.) Department of Civil Engineering, Mohamed El Bachir El Ibrahimi University, 34030 Bordj Bou Arreridj El-Anasser, Algeria Toufik Karech and Rafik Demagh: Department of Civil Engineering, Mohamed El Bachir El Ibrahimi University, 34030 Bordj Bou Arreridj El-Anasser, Algeria Oualid Limam: Laboratory of Civil Engineering, University of Tunis El Manar, National Engineers School of Tunis, BP 37, 1002 Tunis Le Belvédère, Tunisia Juan Martinez: Laboratoire GCGM, National Institute of Applied Sciences, 20 avenue Buttes de Coësmes CS 70839 - 35 708 RENNES Cedex 7, France | ||