Stability Analysis of Amir Kabir Water Conveyance Tunnel in Strain Softening Condition Using Self-Similarity Method and Convergence-Confinement Curves

Amir Kabir tunnel conveys water from Amir Kabir Dam into Water Refinery Number 6. It is located in the north of Tehran and is considered as a part of the Alborz mountains. In the construction process، the pressure on the support system and installation time of the support system are crucial parameters. Calculation of these parameters in strain softening condition based on convergence-confinement curve is a novel method، and it is the main object of this paper. Using this method، the shotcrete thickness has been reduced by more than 40 percent.