Unexpected ground conditions have always been a major problem for the tunnelling industry. As demand for the development of *XuzTGa"
new underground structures, regardless of the ground conditions, has increased, safety and risk considerations have become even 7=9jXNk Y
more important. The methodology presented in this paper aims at the identification of risk-prone areas, incorporating, at the same H2} i .
time, the uncertainty of ground conditions. It is focused on TBM tunnelling and can be implemented in the early stages of the *:(t.iL
project. The methodology assesses the hazards by introducing the concept of a vulnerability index, which is based on the principles m" G r pE3
of rock engineering systems, to identify the weighting of the parameters, and on probabilistic modelling to address the uncertainty in *h1@eJHMz
the parameters’ values. The proposed model is illustrated via the Athens Metro case study, used also for validating its performance paY%pU
under actual construction conditions.
