DinSAR monitoring of the landslide activity affecting a stretch of motorway in the Campania region of Southern Italy

The paper deals with the landslide activity affecting a wide and steep slope crossed by a stretch of about 2.5 km of the provincial road Tirrena inferiore in the Campania region of Southern Italy. Some years ago, the road has been affected by the partial reactivation of dormant landslides, which caused both severe damages to the piers of a viaduct and considerable road surface deformations. By means of geognostic surveys, laboratory tests, geophysical prospecting as well as rainfall data, the modeling of landslides was performed in detail, and residual slope movements were monitored by means of inclinometers and satellite-based measurements (Cosmo-SkyMed interferometric data). A good correlation there is between the results provided by the two used techniques. With reference to the viaduct failure, DinSAR data allowed to ascertain the date on which the sudden acceleration of the landslide body pointed out the beginning of the landslide reactivation, in its paroxysmal phase. Ground deformations happened starting from January 2014 following an intense rainfall period that has been spreading between December 25 2013 and January 26 2014.