Vaiont Slide, A Geotechnical Analysis Based on New Geologic Observations of the Failure Surface

The large volume and high velocity of the Vaiont Slide combined with the great destruction and loss of life that occurred make it a key precedent landslide, particularly for slides caused by reservoir filling. Engineers and geologists are now generally obliged to examine the slopes of proposed reservoirs for the owners. This report describes the efforts to confirm the existence and nature of clay seams in the slide mass to confirm the possible existence of an 'old' slide at the site. These efforts were made by (a) firsthand field observations of the geology, (b) an examination of preslide and postslide airphotographs, (c) laboratory testing of samples of failure plane materials, and (d) an examination and translation of geologic and other documents related to preslide and postslide conditions.