It is worth mentioning that, although the condition based predictive
maintenance methodology consists of multiple steps as
shown in Fig. 3, two key theoretical components of the predictive
methodology are the model establishment and the life analysis. Recently,
Jiang and the co-workers (Jiang et al., 2012a,b, in preparation;
Yuan et al., in preparation) developed advanced analytics
approaches for establishment and validation of risk models and
damage accumulation models for tunnel seepage. These methods
have been demonstrated with the inspection data collected from
the real-world tunnels. In this paper, the system level lifing analysis
is illustrated with the models established from inspection data
collected from real-world tunnels.