Abstract: This paper presents a case history of numerical simulations of a completed Yaozhai tunnel through the fracturing rock zone construction process. The numerical analysis derived deformation values are compared with the monitoring measured values in the different construction process. The influence of fractured rock mass zone on the tunnel stability was also evaluated and recommendations for the appropriate tunnel supporting method were also provided throughout these evaluations. The results indicate that, the presence of the fracturing rock mass zone indeed has an adverse effect on the stability of the rock mass surrounding the tunnel. Especially, stress concentrations were identified at crest and shoulder of the tunnel. Therefore, these locations should be closely monitored, and the geological predictions should be performed at the excavation area. Both initial and secondary liners should be strengthened for the construction and operation safety of the tunnel.

Key words: fracturing rock zone, stability of rock mass, numerical simulations