Abstract: To better analyze the effect of carbon fiber reinforcement for Nanwa tunnel as a case study, the reinforcement plans with different disease positions of tunnel lining and crack depths are simulated in ANSYS, and corresponding construction techniques and countermeasures are put forward. Analysis finds that only in plan 1 (when cracks of different depths exist on tunnel vault) and plan 2 (when cracks of different depths exist on both tunnel vault and sidewall), the deformation of lining increases obviously with the increase of crack depth before carbon fiber reinforcement, with the maximum displacement 5.81 mm in plan 1 at the center of the inverted arch and the maximum stress 18.80 MPa located in the foot of the arch. After carbon fiber reinforcement, the deformation of lining is greatly reduced, with the maximum displacement in plan 1 cut from 5.81 mm to 3.36 mm, declining by 42.2%, and the maximum displacement in plan 2 decreasing from 6.17 mm to 3.64 mm, dwindling by 41.0%. Result demonstrates that the carbon fiber reinforcement technology has good reinforcement effect on Nanwa tunnel.

Key words: carbon fiber reinforcement, tunnel lining, reinforcement, construction technique, numerical analysis, deep crack, displacement