San Pasquale station of line 6 in Napoli

The paper reports some geotechnical aspects of the design and construction of the San Pasquale Station, intermediate along the stretch of Line 6, which walks across the coastline named Riviera di Chiaia. The station required an excavation deeper 27 m, almost entirely located in pyroclastic sand below the groundwater table. The main shaft is 85.5 m long and 24.1 m large, containing the whole length of the pedestrian platform while a single large section tunnel, built before the excavation of the station shaft, accommodates the two operating rail tracks. Monitoring data will be presented and discussed. Settlements and horizontal displacements represent certainly very significant outcomes among the observed data. Their variations along with time and main construction steps are presented in the paper. The monitoring data have also been submitted to a process of careful interpretation based on the use of numerical analyses to better understand the interaction of deep excavation in a crowded urban area. The FEM code Plaxis has been adopted for such a purpose. Advanced constitutive soil models are available in the software library; however the best compromise between available models and the concrete possibility of properly calibrating their parameters on the basis of the site and laboratory geotechnical investigations was made.