Evaluation of the Support System in Line 4 Tunnel of Tehran Metro at Intersection with Tohid Tunnel and Line 7 Tunnel of Tehran Metro

Considering the progressive use of tunnels in the urban transportation networks، it is essential to investigate the reactions of these structures under seismic dynamic loads. For dynamic analysis of line 4 tunnel، the intersection of Tohid tunnel، line 4 tunnel and line 7 tunnel in intersection of Azadi street and Navab motorway have been studied. This junction is one of the more hazardous area in this project. Moreover، these tunnels have been excavated in different ground levels in soil. Therefore، the model is considered as a continuum media. The objective of dynamic analysis is the evaluation of tunnel support system stability under vibrations of probabilistic earthquakes. Findings prove that no damage occurs in the tunnel support system indicating no need to modify or improve the previously designed support system.