Geomechanical characterization and 3D numerical modeling of complex rock masses: a study case in Italy

摘要

The arch of hills which shuts in the La Spezia Gulf (Liguria Region), has been recently involved in the reactivation of ancient landslides. These movements still cause extensive damages to many buildings, such to declare a state of emergency. Through numerous geognostic surveys we have been able to recognize the high degree of rock masses fracturing, their lithological heterogeneity, the presence of landforms related to ancient and deep gravitative movements and thick debris covers. A geotechnical, kinematic and geomechanical characterization of the landslides and rock masses was carried out. Different constitutive models was applied to the different materials to simulate their mechanical behaviour. Then a 3D numerical modeling was performed to attempt explaining the mechanisms causing the observed landslides, their evolution in term of displacements and deformations. The finite-difference method was applied to estimate the stressstrain response of the slope to the variations of tensional state. An integrate model was performed considering the results of all in situ surveys and numerical modeling: the analyzed model shows main shear strain along the discontinuities deriving from plastic deformation of the mass causing the slope failure. According to the considerations derived from the model, some remedial works are already in progress on the slope.