Polyphase rock slope failure controlled by pre-existing geological structures and rock bridges

Abstract Even after decades of intensive research, assessing rock slope stability remains a challenge. One reason for this is the spatial variability bridges (RBs) related to non-persistent, pre-existing geological structures, especially as detection RBs generally limited post-failure period. Thus, identification and classification their inclusion in numerical studies are demanding, yet essential, since even small quantities can be decisive stability. In our study, we demonstrate how brittle RB failure structures control mechanisms polyphase failure. Therefore, present case study Austrian Alps, where three falls with volume 30,000 m 3 occurred 2019. Based on detailed process reconstructions, high-resolution terrain models, comprehensive mechanical investigations, derived high-quality input distinct element model (DEM). By applying asymmetric Voronoi tessellation DEM, modelled coalescence by As result, identified toppling predominant mechanism at site. Distinctive decisively affected mechanism. However, was only reproducible incorporating DEM pre-failure position. Finally, found that joint persistence, consequently presence potential RBs, controls which initial fall developed. conclusion, state Hüttschlag controlled non-persistent interplay RBs.