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| Titel |
Dynamic interaction of two-phase debris flow with pyramidal defense structures: An optimal strategy to efficiently protecting the desired area |
| VerfasserIn |
Parameshwari Kattel, Jeevan Kafle, Jan-Thomas Fischer, Martin Mergili, Bhadra Man Tuladhar, Shiva P. Pudasaini |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250143080
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| Publikation (Nr.) |
 EGU/EGU2017-6775.pdf |
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| Zusammenfassung |
| In this work we analyze the dynamic interaction of two phase debris flows with pyramidal
obstacles. To simulate the dynamic interaction of two-phase debris flow (a mixture of solid
particles and viscous fluid) with obstacles of different dimensions and orientations, we
employ the general two-phase mass flow model (Pudasaini, 2012). The model consists of
highly non-linear partial differential equations representing the mass and momentum
conservations for both solid and fluid. Besides buoyancy, the model includes some
dominant physical aspects of the debris flows such as generalized drag, virtual mass and
non-Newtonian viscous stress as induced by the gradient of solid-volume-fraction.
Simulations are performed with high-resolution numerical schemes to capture essential
dynamics, including the strongly re-directed flow with multiple stream lines, mass arrest and
debris-vacuum generation when the rapidly cascading debris mass suddenly encounters
the obstacle. The solid and fluid phases show fundamentally different interactions
with obstacles, flow spreading and dispersions, run-out dynamics, and deposition
morphology. A forward-facing pyramid deflects the mass wider, and a rearward-facing
pyramid arrests a portion of solid-mass at its front. Our basic study reveals that
appropriately installed obstacles, their dimensions and orientations have a significant
influence on the flow dynamics, material redistribution and redirection. The precise
knowledge of the change in dynamics is of great importance for the optimal and effective
protection of designated areas along the mountain slopes and the runout zones. Further
important results are, that specific installations lead to redirect either solid, or fluid, or
both, in the desired amounts and directions. The present method of the complex
interactions of real two-phase mass flows with the obstacles may help us to construct
defense structures and to design advanced and physics-based engineering solutions
for the prevention and mitigation of natural hazards caused by geophysical mass
flows.
References:
Pudasaini, S. P. (2012): A general two-phase debris flow model. J. Geophys. Res. 117,
F03010, doi: 10.1029/ 2011JF002186. |
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