Search

The complex time-dependent behavior of two case studies has been studied by performing a 2D numerical simulation. The evolution of the Vajont landslide from 1960 to 1963 catastrophic failure, and of the Mt. de La Saxe rockslide from 2009 to 2012 are examined. Simulations were carried out using the finite difference code FLAC. Firstly, we carried out some shear strength reduction analysis for solving elasto-plastic critical parameters of the basal shear band. Afterwards we applied different timedependent viscous rheological models identifying the Burgers-creep viscoplastic model (Mohr-Coulomb failure criterion coupled with general Burgers-creep model) as the most appropriate one for the simulation of the behaviour of the two phenomena and of large rockslides exhibiting a similar behaviour. Both models have been calibrated and subsequently validated on a long time series of monitoring data.

Alpine rock slopes evolve over long time in changing morpho-climatic settings. In suitable topographic and geomechanical conditions, weakening and increased hydraulic conductivity associated to rock mass damage under gravitational load can result in slow rock slope deformations possibly evolving into fast-moving or catastrophic rockslides. We simulated the long-term evolution of a high-relief alpine slope using a 2D, time-dependent FE numerical model based on static fatigue laws. This simulates slope creep up to tertiary regime explicitly as a function of damage. Model parameters are upscaled from lab to rock mass conditions through a novel approach based on data derived from rock mass characterization. We present a first model test on the rock slope affected by the Spriana rockslide (Central Alps, Italy). We show the ability of damage-based modelling to track long-term evolution from a poorly disturbed rock mass to a mature rockslide system through diffuse and localized damage.

Volcanic rocks are widespread in different geological contexts and exhibit complex behaviors, from hard to extremely soft rocks, depending on mineralogy, porosity, and weathering. In particular, their mechanical properties are influenced by the size and shape of pores. We report the results of porosity characterization by different techniques, performed on lavas with different degrees of alteration, sampled in the Campi Flegrei area (Italy) and characterized through petrographic analyses. Bulk-specific weight measurements, water immersion and Hg-porosimetry gave total and interconnected porosity values. Analysis of thin sections provided 2D pore size and shape estimates and insight in pore relationships with rock matrix and weathering. X-ray Computer Tomography allowed complete 3D reconstruction of rock pores. Different image processing methods for data extraction and analysis have been used to develop a standard analysis procedure. Results in terms of measured porosity and pore size and shape distributions obtained by different techniques are discussed

Rockfall phenomena are characterised by a strong variability because of the influence of many different controlling factors. We discuss the lateral dispersion of rockfall trajectories stressing its relevance for designe of passive countermeasures and hazard zonation. 3D numerical simulations have been performed through a new software code able to use both a lumped mass and an hybrid (kinematic-dynamic) approach. Parametric modelling has been performed at different spatial resolution using sets of bilinear simplified slopeds characterised by different mean inclination and roughness.