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Flow slide is a complex failure mechanism that includes both soil mechanical and hydraulic features, of which the elementary ones are depicted in the flow chart in Figure 2. Two important physical (sub-)mechanisms are static soil liquefaction and breaching. For most of the documented cases of flow slides it is not clear to what extent static soil liquefaction and/or breaching played a role. Both mechanisms result in a flowing sand-water mixture, that eventually resediments under a very gentle slope.
Figure 2: Processes possibly involved in a flow slide
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