Rock Slope Failure Mechanisms and Related Hazards
Current Research Projects – S. Sepúlveda
Rock slope failures are source of major hazards in both natural Cordilleran slopes and artificial slopes such as road cuts or mines. Rock slides, falls and avalanches of variable volume pose a threat to critical infrastructure and population. Their origin is linked to variable factors such as climate, seismicity, tectonics, and local geological history. We study rock slope failures by combining fieldwork and engineering geological site reconnaissance, geotechnical analyses, remote sensing data acquisition and processing using techniques such as InSAR, LiDAR or photogrammetry, and numerical modelling tools.
Understanding rock slope failure and coseismic landslide hazard in deglaciated Cordilleran landscapes
Rock slope failures are a major source of landslide hazards in Cordilleran landscapes, which are typically characterized by high altitudes, large relief and dynamic hillslope, fluvial and glacial processes. In western Canada there are several examples of large rock slope failures, such as the 1903 Frank slide, the 1965 Hope slide and the 2010 Mt. Meager slide. Hundreds of rock slides, rock falls and debris flows of variable size occur annually in the region. Furthermore, southwestern British Columbia is located in an area of high seismic hazard, but the risk of landslides induced by large earthquakes is not well understood. The long-term goal of this research program is to understand the factors controlling rock slope failures at different scales in deglaciated high mountain settings, and how the spatial distribution and evolution of such factors in geological time influence the present-day hazard of large rock slides and rock avalanches. Moreover, we aim to understand how large earthquakes may induce failure in marginally stable deglaciated rock slopes. With the resulting models, we will investigate processes such as progressive failure, glacier-slope interaction in glacier margins and the effect of seismic shaking in rock slopes.
Catastrophic rockslides - debris flows in British Columbia and Patagonia
In high latitude mountain areas, combination of paraglacial conditions with heavy rainfall events, for instance atmospheric rivers such as the November 2021 storms in B.C., induce unstable slope conditions. In these environments, large volume catastrophic rock slides are often originated, which may turn into long runout rock avalanches and/or debris flows, posing a significant hazard to local communities and infrastructure downstream. The slides have also the potential of river damming and subsequent outburst floods, and may also induce large displacement waves in lakes or fjords. Recent examples of these landslide phenomena have been observed in both hemispheres in mountain areas of British Columbia and the Patagonian Andes. The project general goal is to expand the understanding of complex slope failure mechanisms leading to catastrophic large volume landslides, by identifying and characterizing those factors controlling slope instability, through the analyses and comparison of selected case studies in B.C. and Patagonia.