Unexpected ground conditions have always been a major problem for the tunnelling industry. As demand for the development of u&m B;:&
new underground structures, regardless of the ground conditions, has increased, safety and risk considerations have become even E<>n0",
more important. The methodology presented in this paper aims at the identification of risk-prone areas, incorporating, at the same (Lo<3a-]
time, the uncertainty of ground conditions. It is focused on TBM tunnelling and can be implemented in the early stages of the Jou~>0,/j
project. The methodology assesses the hazards by introducing the concept of a vulnerability index, which is based on the principles m .le' &
of rock engineering systems, to identify the weighting of the parameters, and on probabilistic modelling to address the uncertainty in 1 n Ib/nY
the parameters’ values. The proposed model is illustrated via the Athens Metro case study, used also for validating its performance BO5F6lyQ0P
under actual construction conditions.
