Author(s): Carlo Gregoretti; Luigi. Montefusco
Linked Author(s): Carlo Gregoretti
Keywords: Debris-flow; Slope stability
Abstract: The instability of a granular slope subject to a seepage flow has been experimentally investigated, with special regard to the conditions associated to the triggering of a debris flow. The set of laboratory tests has been carried out with incoherent monogranular slopes of different inclination angles, subject to different seepage conditions. Experimental evidence show that overland flow plays a crucial role in the triggering of debris flow. A comparison with some theoretical criteria (Takahashi, Chiew& Parker, Worman) for the initiation of an intense solid transport on the plane surface of a granular slope seems to confirm the circumstance that for steep enough slopes (interested by a seepage flow parallel to its surface) any, however small, surficially flowing discharge is able to trigger a debris flow. This result reduces the limit usually accepted for the stability of slopes interested by a seeping flow (a slope angle not greater than the half of the static friction angle), considering a slope failure via debris flow and not only via landslide.
Year: 1999