ABSTRACT
In this chapter, the three phases of tunnelling process (planning/feasibility, engineering and construction) are described, by identifying the actions to be implemented for obtaining a fully serviceable tunnel during its assigned lifetime. The process has to deal with a series of unavoidable uncertainties and unknowns. Consequently, suitable risk management strategies should be defined and continuously adapted during the whole tunnelling process, considering the updated data derived from constant environment surveys and system monitoring.
