Experiences Gathered from the Construction of Napoli Underground

The design of a deep excavation must address a number of issues such as, for instance, the choice of an adequate support system, the definition of the sequence of construction phases, the computation of the stresses in the structural members, and the evaluation of the magnitude and distribution of ground displacements connected to the construction phases and to possible changes of groundwater pressures connected with the excavation. Under these premises, in the paper it is presented a summary of the main results obtained by an intense monitoring program carried out in the occasion of the construction of deep excavations in the densely urban environment of Napoli (Italia) for the completion of the existing Underground Line 1.