ANALISI DI STABILITÀ DI SCARPATE DI ROCCIA VULCANICA BASATA SU CLASSIFICAZIONI GEOMECCANICHE

This work aims to compare new geomechanical classification systems, ISTV, VSR (M & GG) and VRS, used to measure the stability of volcanic rocks slopes. These latter, usually subjected to rockfall phenomena, show a different behaviour compared to the common rocks slopes on which the main classification systems are based. The survey was performed on 42 slopes along the roads of the island of Tenerife and the data obtained were processed and compared in Excel using tables and graphs. The results obtained show that the undersigned, with little experience on volcanic rocks, tended to overestimate the susceptibility to instability and underestimate the stability with respect to the real behaviour of the slope. As far as the comparison between the indices is concerned, ISTV is faster and allows to measure a grade of susceptibility to instability close to reality, while VSR generally tends to overestimate the stability of the slope. Instead, the VRS geomechanical classification does not allow correlations with slope stability. The susceptibility indexes are a preliminary assessment of the hazard of landslides and are very important because they allow, thanks to an easy and fast applicability, to highlight on large areas the particularly critical zones, on which detailed geotechnical studies will be made and mitigation measures taken. A specific susceptibility index should be created for each region (defined on the basis of the predisposing factors) which allows to optimize the times and costs of intervention and minimize the risk of landslide.