The Behavior of the Highly Weathered and Partially Decomposed Flysch in the Reactivation of Landslide Phenomena in Greece

Abstract

Some of the most serious landslide movements in Greece are often observed in the upper zone of weathered flysch and can be classified as composite landslides. This paper describes the landsliding behavior of highly weathered and tectonically decomposed flysch in a characteristic landslide in Western Greece, focusing on its physical and mechanical parameters, such as moisture content, clay percentage and shear strength. Back analysis was carried out in order to estimate the cohesion and angle of friction at the time of failure. The behavior of the flysch formation was also examined with the use of shear-related tests. All results were cross-examined, and it was concluded that weathered flysch in Western Greece is a landslide-prone material with small amounts of clay minerals, and its sliding behavior is mainly controlled by the rising of the water table and the tectonic activity.