ABSTRACT
The Gallivaggio landslide falls within the San Giacomo Filippo municipality (Sondrio) and affects a portion of slope situated in the lower Spluga Valley. The rock cliff overlooks the “Madonna di Gallivaggio” Sanctuary (17th century), a restaurant, a few houses and a section of the National Road no. 36 “del Lago di Como e dello Spluga” which leads to the tourist resort of Madesimo and to the Spluga Pass on the Swiss border. Hence the need for careful planning of control and design tools aimed at both risk management and risk mitigation. The first monitoring activities of the rock cliff date back to 2006, while in 2011 a survey activity with GBInSAR technology was started by the Geological Monitoring Centre of ARPA Lombardia (CMG). On 29th May 2018, a rock mass of about 5500–6000 m3 detached from the top of the rock cliff, completely filling up the existing catchment ditch behind the protection wall, demolishing part of the defence works and affecting the Sanctuary, the National Road and part of the other accommodation facilities situated at the foot of the rock face. This rockfall, as well as other minor recent falls, allowed to recognize the urgent need for a more adequate protection works. As a first step of a complex of works for the mitigation of the rockfall hazard, a new earth reinforced embankment was conceived. Both phases, designing and building, are described in the paper.
