Slope Failure in Metarmophic Rocks

The photo of this failure was donated by EDAFOMICHANIKI SA, as part of a failure investigation project in Greece. The local geology consists of metamorphic and ploutonic rocks, mainly granite and gneiss and also Quaternary landslide debris deposits. The area of the failure surface is 6300 square meters and affected 140m of the under-construction highway and 50m of the construction service road located above the highway. The units are greatly deformed and foliated with a foliation that generally was not affecting the stability of the excavation and the highway. However, along the failure length the orientation of the foliation changed and formed a zone of weakness that resulted in the failure of the excavation.