Hydro-mechanical characterization of the pyroclastic cover at the Salerno test site (Southern Italy)

A significant portion of the Campania region is mantled by loose pyroclastic soils deposited by the eruptions of Roccamonfina, Campi Flegrei, and Somma-Vesuvius. These deposits, which remain partially saturated for most of the year, are highly susceptible to flow-like landslides triggered by intense rainfall events. Rainwater infiltration reduces matric suction and, consequently, soil shear strength, facilitating slope failure. The PROMISE project - ‘Integrated appPROach for MItigation of flowSlidE risk: full-scale test and advanced numerical modelling’—aims to investigate triggering mechanisms of flow-like landslides through a true-scale experiment consisting of observing the effects of an intense artificial rainfall on an instrumented slope. To this end, a test site is currently being developed in the municipality of Salerno. This paper presents preliminary results from the hydro-mechanical characterization of the pyroclastic cover identified at the site, including hydraulic tests (constant head permeameter and evaporation tests) and mechanical tests (direct shear and triaxial compression) performed on undisturbed soil samples. The resulting geotechnical properties will support numerical analyses that are essential for the design and implementation of the full-scale experiment.