Evaluation of the capacity of the final tunnel lining under earthquake conditions based on non-linear analysis of the ground structure

Document Type : Original Article

Authors

1 Department of Civil Engineering, South Tehran Branch, Islamic Azad University, Tehran,Iran

2 Faculty member,Structure and Earthquake group, Department of Civil Eng Islamic Azad Uni, South Tehran branch

Abstract

Since the analysis of underground structures under seismic conditions is done based on nonlinear ground and linear structures, considering the nonlinear behavior of the soil and tunnel against earthquakes is important in order to achieve real responses. In this regard, in addition to linear analysis, nonlinear seismic analysis of the Tehran Metro tunnel by quasi-static method using ABAQUS software was investigated. The damaged concrete behavior model and mohr-coloumb model were used for tunnel lining and soil in numerical simulation, respectively. The simulations were carried out under three conditions of free field, ovaling, and racking, and at two levels of hazardous earthquake of Operation Design Earthquake (ODE) and Maximum Design Earthquake (MDE). Then, the structural capacity curve and the behavior coefficient for the final tunnel lining were obtained. The results showed that the stresses status and the damage caused to the tunnel lining in each of the three conditions are similar. According to the results of the simulations, behavioral coefficient by considering the importance of the tunnel structure for risk level 1 and 2 were proposed 1-1.5 and 2.5, respectively. The results also indicated that in the linear analysis mode, the tunnel final structure is responsive to the ODE conditions, but it does not suffice for MDE condition. On the other hand, the tunnel lining is safe in the both situations with considering the nonlinear analysis, and applying the behavior coefficient.

Keywords

Asas Journal
Volume 20, Issue 51
September 2018
Pages 52-63

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History

  • Receive Date: 10 June 2018
  • Revise Date: 24 October 2018
  • Accept Date: 11 November 2018

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