Descripción del proyecto
Un análisis más detallado de los corrimientos de tierras de largo recorrido
Una sola roca no puede ir más allá de la altura desde la que cayó, un hecho que se basa en un simple argumento de balance energético. Con todo, los estragos de muchos corrimientos de tierras llegan hasta distancias aparentemente seguras y alejadas de su origen. Los científicos siguen estudiando estos corrimientos de tierras de largo recorrido. Comprender cómo y cuándo ocurren estos corrimientos ayudará a mitigar y predecir los peligros. Hace poco, unos investigadores experimentaron con simulaciones bidimensionales idealizadas de discos circulares y respaldaron el mecanismo de «fluidización acústica». Sin embargo, todavía queda trabajo por delante para demostrar que este mecanismo es una característica de los flujos tridimensionales reales y que resulta robusto en una variedad de condiciones. En este sentido, el equipo del proyecto kelbus2, financiado con fondos europeos, llevará a cabo experimentos de laboratorio y simulaciones tridimensionales de flujos granulares con mediciones simultáneas de presión y velocidad.
Objetivo
Landslides, the violent motion of large masses of debris, rock or snow, are an ever-present danger in mountainous regions the world over. After the landslide material falls down the mountainside, it will run out some distance away from the mountain even on relatively flat surfaces until the energy it gained from falling is dissipated by friction with the terrain. Although a simple energy balance argument suggests that a single rock cannot travel farther than the height from which it fell, many landslide runouts extend their ruin to seemingly safe distances far removed from their origin. These long runout landslides have baffled scientists for over a century, ever since Albert Heim recorded his study of the Elm rock landslide that devastated the village of Elm, Switzerland in 1881. There are many explanations for this phenomenon, such as lubrication by an interstitial fluid, but none of these satisfactorily addresses how a completely dry landslide can run out so far. Not understanding how and when long runouts will occur makes hazard mitigation and prediction extremely difficult, highlighting the urgency of this issue. Recently, Melosh and coworkers have provided support for a mechanism borrowed from the fluidization of impact craters, “acoustic fluidization”, by using idealized 2D simulations of circular disks, but more work is needed to show that this mechanism is a feature of real 3D flows and robust for a range of conditions. We will perform laboratory experiments and fully 3D simulations of granular flows using simultaneous pressure and velocity measurements to test the acoustic fluidization hypothesis. We will also look for a crossover between this dry mechanism and the lubrication mechanisms for wet landslides. Besides application to landslide engineering, we will also explore for the first time how fundamental features of granular flows such as shear flow instabilities (clustering and longitudinal stripes) affect the rheology of landslides and long runouts.
Ámbito científico
Programa(s)
Régimen de financiación
MSCA-IF-EF-ST - Standard EFCoordinador
33000 Bordeaux
Francia