The evolution of slope failures: mechanisms of rupture propagation Department of Geography, University of Durham, County Durham, UK
Abstract. Forecasting the occurrence of large, catastrophic slope failures remains very problematic.
It is clear that in order advance this field a greater understanding is needed of the
processes through which failure occurs. In particular, there is a need to comprehend
the processes through which a rupture develops and propagates through the slope, and
the nature of the inter-relationship between the stress and strain states of the
landslide mass. To this end, a detailed analysis has been undertaken of the movement
records for the Selborme Cutting slope failure, in which failure was deliberately
triggered through pore pressure elevation. The data demonstrate that it is possible
to determine the processes occurring in the basal region of the landslide, and thus
controlling the movement of the mass, from the surface movement patterns. In particular,
it is clear that the process of rupture development and propagation has a unique
signature, allowing the development of the rupture to be traced from detailed surface
monitoring. For landslides undergoing first time failure through rupture propagation,
this allows the prediction of the time of failure as per the "Saito" approach. It is
shown that for such predictions to be reliable, data from a number of points across
the landslide mass are needed. Interestingly, due to the complex stress regime in
that region, data from the crown may not be appropriate for failure prediction.
Based upon these results, the application of new techniques for the detailed assessment of
spatial patterns of the development of strain may potentially allow a new insight into the
development of rupture surfaces and may ultimately permit forecasting of the temporal
occurrence of failure.
Citation: Petley, D. N.: The evolution of slope failures: mechanisms of rupture propagation, Nat. Hazards Earth Syst. Sci., 4, 147-152, doi:10.5194/nhess-4-147-2004, 2004.