Issue 66

W. Frenelus et alii, Frattura ed Integrità Strutturale, 66 (2023) 56-87; DOI: 10.3221/IGF-ESIS.66.04

results monitoring could be modified after a certain time of tunnel operation. Hence, effectively predicting the safe operation of tunnels at any time based on convergence deformation requires effective continuous monitoring systems.

Figure 11: (a) A scanning operation at a tunnel site; (b) Gained point cloud for tunnel 3D surface (After Jiang et al. [20], with permission from Elsevier).

Figure 12: Illustration of tunnel failure generated by convergence deformation: (a) cracks on shotcrete; (b) partial closure on the secondary lining (from [20], with permission from Elsevier).

Figure 13: Convergence deformation measured at the Shuangjiangkou Hydropower Station by: (a) FBG sensors; (b) Digital photogrammetric System (From Zhang et al. [98], with permission from Elsevier).

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