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| Titel |
Precursory Acoustic Emissions from Bench-Scale Landslides |
| VerfasserIn |
D. Cohen, M. Schwarz, G. Michlmayr, D. Or |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250029771
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| Zusammenfassung |
| Rapid and shallow hydrologically-triggered landslides may result from initiation of local slip
failures and deformations that eventually coalesce to global failure along a shear surface.
These local small failure processes reflect complex interactions of shear, tensile, and
compression forces resulting from dynamic formation of force chains, collapse of
grain cementing, load redistribution by root failure, and pore-water pressure due to
water infiltration. We study how local failures and deformations may be used as
precursory warning signals to landslides by monitoring acoustic emissions and imaging
formation of tension-cracks during small bench-scale landslides of sand using an
inclined sand box. Sands of various sizes and water contents failed as slope-angle was
increased or during simulated rain infiltration. Acoustic emission (AE) sensors placed
either directly in the sand or on metallic waveguides recorded the high-frequency
pressure waves produced by granular friction and rolling. A high-speed camera
synchronized to the AE system captured the initial formation of tension cracks in the
upper portion of the slide. A laser profiler measured the initial and final states of
the slope to estimate the position of the slip surface and the volume of the slide.
Precursory acoustic signals were analyzed using statistics of acoustic emissions to
determine criteria for incipient failure. Results from these experiments could potentially
provide the basis for monitoring activities in support of an early warning system. |
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