Rheometrical experiments with monitoring of resistivity and induced polarization: For a better understanding of the solid-fluid transition in clayey landslides

• Published in: Landslides and Engineered Slopes. Experience, Theory and Practice Vol. 1; pp. 587 - 594
• Main Authors: Carrière, S.R., Bièvre, G., Jongmans, D., Larose, E., Chambon, G., Lebourg, T.
• Format: Book Chapter
• Language: English
• Published: CRC Press 2016
• Edition: 1
• Subjects: Oscillatory Tests; Mineralogical Structure; Solid Fluid Transition; Induced Polarization; Phase Shift; Normalized Chargeability; Electrical Measurements; Overburden; Shear Rate; Southern French Alps; Elastic Shear Modulus; Clay Samples; Shear Stress; Critical Shear Stress; Slope Stability Analysis; Electrical Parameters; Flume Experiments; Rheometrical Tests; Electrical Resistivity; Debris Flow; Rheometrical Experiments; Pore Tortuosity; Anionic Composition; Yield Shear Strength; Pore Connectivity
• ISBN: 1138029882; 9781138029880
• DOI: 10.1201/9781315375007-55

Clayey landslides acting like debris-flows when experiencing fluidization represent serious threats for populations and infrastructures and have been the subject of numerous works in the past decade. Recent studies have shown that the shear-wave velocity Vs (linked to the stiffness of the material), could potentially be used as a precursory parameter for earthflow activation. However, the transient mechanism explaining this precursory behavior remains uncertain and the solid-fluid transition is still poorly understood. A complementary way to understand these processes is to monitor electrical clay parameters such as resistivity and induced polarization. It is well known that these electrical parameters are sensitive to the clay water content, pore tortuosity and connectivity, which are likely to exhibit some changes during fluidization. Rheometrical experiments with electrical measurements have been performed on clay samples coming from four flow-like landslides of the Alpes. The results show that 1) resistivity does not seem to be sensitive to the clay fluidization and 2) Induced polarization seem to be sensitive to this transition. These new results and what they entail in terms of solid-fluid transition mechanisms are discussed in this paper. Clayey landslides acting like debris-flows when experiencing fluidization represent serious threats for populations and infrastructures and have been the subject of numerous works in the past decade. The transient mechanism explaining this precursory behavior remains uncertain and the solid-fluid transition is still poorly understood. Rheometrical experiments with electrical measurements have been performed on clay samples coming from four flow-like landslides of the Alpes. Four different clay samples have been tested all of them coming from four flow-like landslides: Trieves, Super-Sauze, Char d'Osset and Pont-Bourquin. Electrical measurements have been made during oscillatory tests, allowing both the monitoring of electrical parameters and the elastic shear modulus of the sample. A complementary way to understand these processes is to measure the electrical resistivity and the induced polarization during the same rheometrical tests. A complementary way to understand these processes is to monitor electrical clay parameters such as resistivity and induced polarization.