| Title | Effects of geometry and soil properties on type and retrogression of landslides in sensitive clays |
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| Author | Wang, C; Hawlader, B; Perret, D; Soga, K |
| Source | Geotechnique vol. 72, issue 4, 2020 p. 322-336, https://doi.org/10.1680/jgeot.20.P.046 |
| Image |  |
| Year | 2020 |
| Alt Series | Natural Resources Canada, Contribution Series 20210406 |
| Publisher | ICE Publishing |
| Document | serial |
| Lang. | English |
| Media | paper; digital; on-line |
| File format | pdf |
| Subjects | Science and Technology; Nature and Environment; geophysics; landslides; deformation |
| Program | Public
Safety Geoscience Intraplate Earthquakes |
| Released | 2020 12 14 |
| Abstract | Flowslide and spread are two common types of landslides in sensitive clays. Empirical criteria, based on single or multiple soil properties and slope geometry, have been proposed for a rough assessment
of potential landslide type and retrogression distance. A large variation has been found in the comparison of retrogression distance between empirical equations and field data. In the present study, flowslides and spreads are simulated using a
Eulerian-based large-deformation finite-element (FE) method. In addition to strain-softening, a strain-rate-dependent undrained shear strength model that elevates the strain rate effects on the shear strength of liquefied clay flowing at high speed
is used. In flowslides, a higher rate of increase in undrained shear strength with depth reduces the depth of subsequent slides, and thereby the retrogression distance. The maximum retrogression occurs for a uniform shear strength profile. The
increase in the ratio of horizontal to vertical stress, resistance to downslope movement of the debris and decrease in soil brittleness and slope steepness change the failure pattern from a flowslide to a spread. |
| Summary | (Plain Language Summary, not published)
Flowslides and spreads are the two main types of very large landslides that can occur in clays in Eastern Canada, part of British Columbia and Alaska,
and in Scandinavia. These landslides can be triggered by natural causes such as bank erosion along watercourses, heavy or prolonged rainfall, and earthquakes, as well as inappropriate human activities such as slope toe excavation or overloading at
the slope crest, uncontrolled water drainage, vibrations induced by blasting, etc. One of the most problematic issues for land-use planning and public safety is to determine the probable spatial extend of future landslides. This paper presents
results of numerical models allowing the identification of the critical factors controlling the development of these landslides, and an estimation of their spatial extend. |
| GEOSCAN ID | 329240 |
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