The engineering behaviour of clays is highly complex as it strongly depends on the interplay of mechanical stresses and stress history, moisture and hydraulic pressures, mineral and pore fluid chemistry, temperature and thermal history. Indeed, constitutive model formulations need to account for a variety of intimately coupled processes to accurately describe the response of clays to complex external forcings. There is evidence that both chemo- and thermo-mechanical coupled processes may play a role in the stability and kinematics of clay-rich slopes by acting, in particular, on the available shear strength in the landslide slip zone. However, exhaustive laboratory characterisations are lacking, particularly with respect to the direct effect of temperature on the residual shear strength and viscous deformations under constant stress. In the proposed project, the candidate is expected to carry out an experimental programme to characterise the residual shear strength as a function of mineralogy, confining pressure, shear rate, pore fluid chemistry, and temperature, and relate it to more easily determinable index properties and soil parameters. The results will be used to formulate empirical and physically-based models of slope stability and landslide kinematics that could be applied to slope-scale and catchment-scale assessments.
Deadline is closed
