Plane slope failures in the Langhe region of Italy

Widespread plane slope failures have occurred in the hilly Langhe region (NW Italy) over the past two centuries and more recently in November 1994. The 1994 event caused the deaths of 20 people and major damage to properties. This paper is a description of the landslides that occurred in connection to flexural slip. The causes of the phenomena are discussed in detail, including the variation of the residual strength along the shear surface as a result of specific geological, chemical and mineralogical conditions. After examining the phenomena that contribute to create slide-prone slopes, the paper concentrates on the driving mechanisms applying to the case histories investigated.