Rockfall hazard assessment at Mt. San Costanzo (Sorrento Peninsula, Italy)

摘要

Mt. San Costanzo, located in the southwestern sector of the Sorrento Peninsula, Italy, is a Mesozoic carbonate monocline whose repeated rockfalls affected, at least since 1960s, the foothill hamlets of Nerano and Marina del Cantone. A geostructural and geomechanical survey was performed at Mt. San Costanzo, devoted to the assessment of the rockfall susceptibility of carbonate rock masses: to this purpose, the Rock Engineering Systems (Hudson 1992) was adopted. Eventually, after a preliminary evaluation of the kinematic feasibility of rock slope instability mechanisms, a rockfall hazard analysis was carried out, using a commercial code based on a probabilistic approach in order to evaluate boulder trajectories and the related potential of invasion; the availability of a high-scale digital contour map allowed a 3D visualization of block motion. The results evidenced that large sectors of Nerano and Marina del Cantone are under the threat of rockfalls from Mt. San Costanzo. Finally, a tentative zonation of the urban areas exposed to the rockfall hazard was drawn.