| Autor: |
Eric Larose, Guillaume Chambon, Laurent Baillet, Denis Jongmans, Guénolé Mainsant |
| Rok vydání: |
2015 |
| Předmět: |
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| Zdroj: |
Engineering Geology. 192:26-32 |
| ISSN: |
0013-7952 |
| DOI: |
10.1016/j.enggeo.2015.03.019 |
| Popis: |
Clay slopes are susceptible to suddenly liquefy into rapidly accelerating landslides, thereby threatening people and facilities in mountainous areas. Because the shear-wave velocity ( V s ) characterizes the medium stiffness, this parameter can potentially be used to investigate the rheological behavior of clay materials before and during the solid-to-fluid transition associated to such landslide failures. Previous rheometrical studies performed on clay samples coming from Trieves landslides (French Alps) have established that this material behaves as a yield stress fluid with a marked viscosity bifurcation. When the applied stress reaches a critical level, the viscosity decreases abruptly, along with V s which tends to zero in the fully fluidized material. Here, we monitor the Rayleigh wave velocity ( V R ) variations in a saturated clay layer placed in a flume and progressively brought to failure by tilting the device. Experiments performed on clay samples with different water contents show a significant relative drop in V R values (and hence in V s ) before the onset of the mass movement. Additional rheometrical analyses point out that this precursory drop in V s is presumably due to a complex transient rheological response of the clay. These new results confirm that V s variations constitute a good indicator for monitoring clay slope stability. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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