Fig. 1. Finite element model of lining ring (a) and reinforcement (b)

Fig. 2. Static analysis finite element model (a), model meshing (b) and geostress equilibrium displacement nephogram (c)

Fig. 3. Tunnel Mises equivalent stress nephogram (a) and displacement nephogram (b)

Fig. 4. The first nine order results of modal analysis

Fig. 5. Overall model (a) and tunnel (b) acceleration nephogram

Fig. 6. The acceleration curve of the tunnel at eight clock

Fig. 7. Fiber optic grating displacement meter (a) and its installation schematic diagram (b)

Fig. 8. Fiber optic grating surface-patch strain meter (a) and its installation schematic diagram (b)

Fig. 9. Distributed fiber optic vibration sensing system, sensing optical cable and software interface

Fig. 10. Sensing optical cable display schematic diagram in the tunnel

Fig. 11. Verification point location schematic diagram

Fig. 12. The reading of fiber optic grating displacement meter on A point of section S1

Fig. 13. The reading of fiber optic grating displacement meter on A point of section S2

Fig. 14. The reading of fiber optic grating displacement meter on A point of section S3

Fig. 15. Crush damage radar maps of three sections in working condition A

Fig. 16. Pulling damage radar maps of three sections in working condition A

Fig. 17. Crush damage radar maps of three sections in working condition B

Fig. 18. Pulling damage radar maps of three sections in working condition B