Interaction of extremely slow landslides with transport structures in the alpine glacial Isarco valley

This paper describes three cases of extremely slow landslides located in the Isarco Valley, and interacting with major transport infrastructures connecting Italy to the central Europe: SS12 State Road, A22 (E45) Motorway, Verona-Brennero rail-way, high-speed railway network TNT-T5. Field measurements of displacements and pore water pressure were carried out to understand the mechanism of landslide evolution and the interaction with the transport structures. In particular, mobile inclinometers, IPIs, direct pendula and Total Station were used for monitoring the subsurface or structure movements. The landslides were classified as complex landslides. Two of them are associated to DGSDs phenomena. Field and remote measurements of displacements revealed that the interaction with the transport infrastructures was due to deep rotational/translational slides as partial reactivations of the DGSDs. The residual shear strength was developed on the sliding surfaces and therefore these landslides may be classified as active landslides.