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3D numerical investigation of the coupled interaction behavior between mechanized twin tunnels and groundwater – A case study: Shiraz metro line 2

Shivaei, S ; Sharif University of Technology | 2020

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  1. Type of Document: Article
  2. DOI: 10.1016/j.tust.2020.103458
  3. Publisher: Elsevier Ltd , 2020
  4. Abstract:
  5. Mechanized tunneling method using Tunnel Boring Machine (TBM) is being extensively employed in urban areas, especially when excavation takes place underneath the groundwater table. In this study, three-dimensional coupled Finite Element Analyses (FEA) have been performed to investigate the interaction mechanism between mechanized twin tunnels construction of Shiraz metro (line 2) and groundwater. Firstly, two soil constitutive models (Mohr-Coulomb and Modified Cam-Clay model) of Shiraz lean clay are validated against drained triaxial compression test data. Varying the permeability of the grout layer within the specified range, the base numerical model is then calibrated by the field data of ground surface settlements. Parametric studies are conducted subsequently to evaluate the effects of influencing factors involved in the coupled FEA of twin tunnels, including the drainage boundary condition of the grout layer, the position of groundwater level, and the rest interval between excavations of twin tunnels. The numerical results indicate that the ground surface settlements and internal forces of existing segmental lining are greatly influenced by the drainage condition of the grout layer. Also highlighted is the marked effect of the drainage condition of the grout layer in the numerical prediction of the interaction behavior between mechanized twin tunnels and groundwater in different cases of the groundwater level and the rest interval between excavations of twin tunnels. © 2020 Elsevier Ltd
  6. Keywords:
  7. 3D Numerical simulation ; Consolidation analysis ; Drainage condition ; Groundwater ; TBM (EPB) ; Twin tunnels ; Boring machines (machine tools) ; Compression testing ; Drainage ; Grouting ; Mortar ; Settlement of structures ; Soil mechanics ; Tunneling (excavation) ; Tunneling machines ; Coupled finite element analysis ; Ground surface settlements ; Interaction mechanisms ; Modified Cam-clay model ; Numerical investigations ; Soil constitutive model ; Tri-axial compression tests ; Tunnel boring machine(TBM) ; Construction equipment ; Finite element method ; Groundwater ; Metro system ; Permeability ; TBM ; Three-dimensional modeling ; Tunnel ; Tunneling ; Fars ; Iran ; Shiraz
  8. Source: Tunnelling and Underground Space Technology ; Volume 103 , 2020
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0886779820304120