Přehled
The mechanical behaviour of clays emerges from coupled processes occurring at the micro- and macro-levels, that depend on both the current state and the stress-thermal history. To reproduce these behaviours, constitutive models need to rely, for calibration, on experiments highlighting the effects of coupled processes. Thermo-hydro-mechanical coupling is particularly evident in clay-rich soils. However, experimental efforts have thus far focused on volumetric and small-deformation behaviours or on very high temperature regimes, neglecting large deformations in near-environmental conditions. To fill this gap, we plan a laboratory campaign to cover a range of temperature and stress conditions, relevant not only to “static” engineering applications (e.g., nuclear waste repositories) but also to conditions typical of active landslide shear zones. The campaign includes the evaluation of the residual shear strength under various thermal conditions and displacement rates, and shear-controlled tests (creep tests) in an ad-hoc modified device. The latter will better reproduce the conditions occurring in shear zones of slow-moving landslides, which are sensitive to even small changes of temperature that could result from atmosphere-soil interactions and could be altered, in short to long terms, by climate change. The results will be used to adapt constitutive models (e.g., hypoplasticity) to perform slope stability assessments.
