Engineering geological investigation of rock mass in Isfahan subway route (south section) and its support system analysis

The present study attempts to classify rock behavior in Isfahan subway tunnel between Azadi square and University stop. The geomechanical classification (RMR), rock mass quality index (Q), and geological strength index (GSI) have been used. Since the most common damages in shallow tunnels and jointed rock mass have been observed in wedge sliding in the ceilings and walls, the Unwadge software was used for data analysis. The study also estimated the appropriate supporting systems for possible wedges. Obviously, the study and analyzing the supporting systems need enough understanding of geomechanical parameters and the deformability of the including rock mass. GSI has been used to determine such parameters. Following the establishment of such parameters, the numerical method together with Phase2 software were used to analyse the tunnels and their maximum displacement.