Slope Failure

Abstract

On October, 1 2009 a heavy rainfall hit the limited area on the N-E part of Sicily (Italy) near the town of Messina. At the station of St. Stefano di Briga a rainfall of 223 mm occurred in 7 h with a peak of 10.6 mm in 5 min. During the event many landslides such as sliding, debris flows and mud flows occurred in the 14 villages, causing 37 victims, mainly in the villages of Giampilieri and Scaletta Zanclea. Big damage occurred to the buildings, as well to roads and railways. The event caused about 1,652 homeless and the total cost for the recovery was estimated in about 800 M U.S. dollars. The microzoning of residual risk allows about 50% homeless to come back in the houses located in areas at very low risk. The assessment of the slope instability could be done by empirical correlation or analytical and numerical analyses. Some criteria for the stabilization works for risk mitigation are discussed. As the damaged area is prone to seismic risk (it was shaken by the 1908 Messina and Reggio Calabria earthquake), the analysis of slope instability and the evaluation of the behavior of the stabilization works must take into account the multidisciplinary risk analysis due to heavy rainfall and earthquakes.