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Titel |
Flow-type failures in fine-grained soils: an important aspect in landslide hazard analysis |
VerfasserIn |
T. W. J. Asch, J.-P. Malet |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1561-8633
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Digitales Dokument |
URL |
Erschienen |
In: Natural Hazards and Earth System Science ; 9, no. 5 ; Nr. 9, no. 5 (2009-10-15), S.1703-1711 |
Datensatznummer |
250006990
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Publikation (Nr.) |
copernicus.org/nhess-9-1703-2009.pdf |
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Zusammenfassung |
Forecasting the possibility of flow-type failures within a slow-moving
landslide mass is rarely taken into account in quantitative hazard
assessments. Therefore, this paper focuses on the potential transition of
sliding blocks (slumps) into flow-like processes due to the generation of
excess pore water pressure in undrained conditions. The generation of excess
pore water pressure may be the consequence of deformation of the landslide
body during motion. Two model concepts are proposed and discussed. The first
concept is the so called strain concept model where emphasis is laid
on strain changes due to differential movement within the moving mass. This
may create zones of compression and dilation and consequently excess pore
water pressures. The second concept is the so called
topographical concept model which focuses on changes in the stress
field of the landslide caused by geometric changes in topography of the
moving body. Both models were tested on two slumps which developed in
secondary scarps of the Super-Sauze mudslide in the Barcelonnette Basin
(South French Alps). The slump which developed in 1999 showed complete
fluidization; all the material was removed from the source area and
transformed into a mudflow. The second slump, dated from 2006, did not show
fluidization; it has a relative short displacement and all the material
remained in the source area. It appeared that the strain concept
model predicted flow-type failure for both slumps, after relative short
displacements, while the topographical concept model predicted only
flow-type failure for the 1999 slump and not for the 2006 slump. The
strain concept model seems too conservative in forecasting the
fluidization potential of slumping blocks. |
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