Is illustrative of new state-of-the-art probabilistic procedures to face the challenge of the optimal design of large structures under seismic hazard. Contains reliability-based procedures that includes a management of uncertainties which is easy to understand - Describes a systematic and scientific way to do a cost/benefit analysis which can be adapted to other cases of interest to the readers Offers a stimulating example of how to handle the economic consequences of the potential failure of a large structure Shows, in a practical way, the formulation of key aspects to make decisions and provides orientation to enable the reader to solve similar problems.