The possible role of brittle rock fracture in the 1963 Vajont Slide, Italy

• The importance of brittle fracture and kinematics in the 1963 Vajont Slide.
• The influence of groundwater in the Vajont failure mechanism.
• Simulation results demonstrated a good agreement with field observations.

We use a state-of-the-art numerical simulation approach to investigate the Vajont slope failure, a large catastrophic landslide that resulted in the loss of 1910 lives. This study represents the first three-dimensional (3D) brittle fracture simulation of the Vajont Slide that includes the effect of groundwater on the failure process. A realistic representation of the Vajont slope geometry, failure surface and discontinuities in a 3D lattice spring code allowed us to study the kinematics of the landslide. Using a lattice-spring block model approach, the relations among the number of blocks, slope damage, and stability are investigated. The influence of an elevated groundwater table on displacements and cracking within the model is evaluated. The results show a good agreement with the reported microseismic events prior to the failure. Two new techniques, “damage intensity”, D32, and the “ellipsoid of damage”, are introduced and used to quantify brittle damage within the numerical simulations.