0000000000938803
AUTHOR
L. Laloui
New experimental tools for the characterization of highly overconsolidated clayey materials in unsaturated conditions
This chapter presents some of the experimental facilities that have recently been developed at the EPFL Soil Mechanics Group. Three apparatuses operating in non-isothermal conditions are described in detail: a sorption bench for determining water retention curves, an oedometric cell for analyzing volumetric responses under high vertical loads, and a triaxial cell designed for extreme loading conditions.
An experimental and constitutive investigation on the chemo-mechanical behaviour of a clay. In Bio- and Chemo- Mechanical Processes in Geotechnical Engineering (ISBN: 9780727760531), ICE Publishing, 32-43.
Engineering issues for which the understanding of the chemo-mechanical behaviour of soils is relevant include wellbore stability problems, the salinification of groundwater, and nuclear waste storage. However, despite the vast number of situations in which couplings between chemistry and mechanics occur, the available constitutive models rely on limited experimental evidence. This paper presents the results of an experimental programme on the chemo-mechanical behaviour of a non-swelling illite. The osmotic suction is controlled through the ion concentration of sodium chloride in the pore water. Stress paths include mechanical loading at a constant osmotic suction, and an increasing osmotic …
Sensitive THM coupled analysis of buffer-rock barriers for nuclear waste storage. In Unsaturated Soil Mechanics from Theory to Practice
The buffer-rock barriers system is widely proved to be one of the most promising options for isolating high-level radioactive waste from the human environment. To certify the efficiency and provide the additional development regarding design and assessment of this barriers system, it is essential to understand the complex Thermo-Hydro-Mechanical (THM) behavior of confining buffer under a variety of environmental conditions. To this end, a case of buffer-rock barriers system is studied using a THM finite element approach. The contributions of different processes, including the vapor diffusion process, the water saturation dependent thermal conductivity and specific heat capacity as well as t…
Coupled seismogenic geohazards in Alpine regions
COupled seismogenic GEohazards in Alpine Regions (COGEAR) is an interdisciplinary natural hazard project investigating the hazard chain induced by earthquakes. It addresses tectonic processes and the related variability of seismicity in space and time, earthquake forecasting and short-term precursors, and strong ground motion as a result of source and complex path effects. We study non-linear wave propagation phenomena, liquefaction and triggering of landslides in soil and rock, as well as earthquake-induced snow avalanches. The Valais, and in particular parts of the Rhone, Visper, and Matter valleys have been selected as study areas. Tasks include detailed field investigations, development…
Hydro-mechanical modelling of a natural slope affected by a multiple slip surface failure mechanism
A coupled hydro-mechanical formulation is presented for the analysis of landslide motion during crisis episodes. The mathematical formulation is used to model a natural slope affected by a multiple slip surface failure mechanism, in which pore water pressure evolution was identified as the main cause for movement accelerations. An elasto-plastic constitutive model is adopted for the behaviour of slip surfaces. Material parameters are obtained by combining the available laboratory tests and the back analysis of some crisis episodes. After being calibrated and validated, the model is applied to improve the understanding of the physical processes involved and to predict the landslide behaviour…
Advances in Laboratory Testing and Modelling of Soils and Shales (ATMSS).
This volume contains the invited keynote and feature lectures, as well as the papers that have been presented at the workshop. The topics of the lectures and papers cover a wide range of theoretical and experimental research, including unsaturated behaviour of soils and shales, multiphysical testing of geomaterials, hydromechanical behaviour of shales and stiff clays, the geomechanical behaviour of the Opalinus Clay shale, advanced laboratory testing for site characterization and in situ applications, and soil–structure interactions.