The Scascoli case study (Bologna - Italy): design and safety measures of a large landslide area

Landslide processes commonly occur on both sides of the Scascoli Gorge. The valley floor is flanked by vertical sandstone walls 40 to 80 m high, as well as steep slopes of heavily fractured and weathered rocks. The most important rockfalls known up to date occurred from the left valley side in 1992, 2002 and 2005, when a rock wedge called Mammellone 1, collapsed by a large and complex rockslide, with an estimated volume of 30.000 m3. The collapse of the Mammellone 1 shifted the riverbed to the right valley side where, just a few weeks later, a roto-translational earth slide was triggered by the consequent undermining process. In order to rehabilitate the local road, three safety interventions were planned in the following order: (a) reshaping the residual wall of the Mammellone 1; (b) removing the shallow earth slide from the right valley side, and consolidating its detachment zone; (c) carrying out training works on the riverbed, and reconstructing the road embankment.