Geomechanical modelling and stability analysis of the shallow underground water reservoir ‘Palombaro Lungo’ (Matera-Italy)

Abstract The city of Matera, as several other ancient historical cities and towns, is recovering a large part its parts developing policy urban regeneration. In the early 90s, during restoration works main square, Piazza Vittorio Veneto, it was re-discovered huge underground space used water reservoir named Palombaro Lungo . It built linking pre-existing smaller caves completed at end nineteenth century making impermeable with cocciopesto (opus signinum) technique. hypogeum dug in Plio-Pleistocene rock called Gravina Calcarenite. calcareous sandstone weak good mechanical properties, low permeability easy to be dug. internal geometry thicknesses above reconstructed by integration topographic GPR surveys. paper presents geo-mechanical model evaluation about stability this structure. analysis were developed using numerical code UDEC for transect assuming blocks deformable, trying address evolution stress–strain conditions. case study can considered an example general interest rupestrian longed form, where one planimetric dimension strictly prevails over other. Numerical simulations showed state compatible fractures detected situ confirmed absence instability problems groundwater reservoir.