Unexpected ground conditions have always been a major problem for the tunnelling industry. As demand for the development of jWb\"0)
new underground structures, regardless of the ground conditions, has increased, safety and risk considerations have become even ? _h#>
more important. The methodology presented in this paper aims at the identification of risk-prone areas, incorporating, at the same a!6OE"?QQ
time, the uncertainty of ground conditions. It is focused on TBM tunnelling and can be implemented in the early stages of the CB7R{~
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project. The methodology assesses the hazards by introducing the concept of a vulnerability index, which is based on the principles .q& ]wu
of rock engineering systems, to identify the weighting of the parameters, and on probabilistic modelling to address the uncertainty in & /FA>
the parameters’ values. The proposed model is illustrated via the Athens Metro case study, used also for validating its performance !z&seG]@
under actual construction conditions.
