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| Titel |
Monitoring internal deformation of unstable cohesionless slopes: insights from DEM modeling |
| VerfasserIn |
Zhina Liu, Hemin Koyi |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250056996
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| Zusammenfassung |
| Most of previous studies on landslides focus on surface displacements using field data and
monitoring techniques and/or progressive propagation of a failure surface using
numerical modeling. However, few studies focus on the mode and style of internal
deformation of a sliding mass during landslides. In this study, unstable cohesionless slope
models with three different internal friction angles (θ=19Ë , 30Ë and 35Ë ) were
simulated with particle flow modeling. We mainly monitored and quantified the internal
deformation of the sliding mass, investigated the characteristics of displacement within
the sliding mass and analyzed the topography change of the slope surface during
landslides. In addition, the effect of internal friction on the deformation of the sliding
mass was studied. Model results show the following features related to a sliding
mass:
(1) The sliding mass glides downwards in a wavy pattern with a distinctive velocity
heterogeneity both in time and in space which results in a wavy displacement contour lines.
Model results show that the mass slides faster and further in the model with lower internal
friction and the sliding area (volume in 3D) increases with decreasing the internal friction. (2)
The slope surface topography changes from a straight line in the undeformed stage to several
slopes with slope breaks which become steeper towards the toe of the sliding mass.
The slope angle at the bottom indicates more or less the internal friction angle of
the sliding material. However, the slope surface remains as a straight line in the
models with very low internal friction (θ=19Ë ). (3) Dilatation occurs within the
sliding mass due to the increase of porosity during the movement of the sliding
mass. Volumetric strain grows larger in the model with higher internal friction.
(4) The sliding mass deforms internally and heterogeneously. The distribution of
extension axes shows a wavy flow similar to the velocity vector fields. Generally, in all
models, strain magnitude increased from the failure surface to slope surface. However,
strain becomes larger at the location where the extensional orientation changes. |
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