hidden - assigned and confirmed by the Study Dept.
Date of registration:
17.11.2021
Date of assignment:
17.11.2021
Confirmed by Study dept. on:
17.11.2021
Advisors:
Marco Loche, M.Sc., Ph.D.
Preliminary scope of work
The residual shear strength controls the stability and mobility of landslides that move along regular slip surfaces after large displacements. It is, therefore a fundamental parameter in soil mechanics. The residual shear strength is independent of the soil's initial state and stress history as it can only be attained upon further shearing beyond the critical state strength. However, abundant experimental literature demonstrates that the rate at which a soil is sheared can condition the available strength. Similarly, soils at different temperatures, sheared under the same confining pressure and shearing rate, can exhibit different strengths. The combination of shearing rate and thermal effects can effectively control the fate of landslides, determining whether they can attain large velocities and long runout distances, and thus whether they can be highly destructive. Both the mineral composition and the confining pressure have been found to control the shear rate and thermal response of soils, but the available data are insufficient to construct a comprehensive model. The proposed thesis work focuses on designing and implementing enhancements to existing experimental devices to enable accurate control of temperature during shearing as well as to achieve control on the applied shear force to conduct shear creep experiments. The work is necessary in order to carry out a experimental campaign to enrich the available dataset by means of systematic testing of selected clayey soils under various stress and thermal conditions, and to provide a preliminary empirical interpretation.
Preliminary scope of work in English
The residual shear strength controls the stability and mobility of landslides that move along regular slip surfaces after large displacements. It is, therefore a fundamental parameter in soil mechanics. The residual shear strength is independent of the soil's initial state and stress history as it can only be attained upon further shearing beyond the critical state strength. However, abundant experimental literature demonstrates that the rate at which a soil is sheared can condition the available strength. Similarly, soils at different temperatures, sheared under the same confining pressure and shearing rate, can exhibit different strengths. The combination of shearing rate and thermal effects can effectively control the fate of landslides, determining whether they can attain large velocities and long runout distances, and thus whether they can be highly destructive. Both the mineral composition and the confining pressure have been found to control the shear rate and thermal response of soils, but the available data are insufficient to construct a comprehensive model. The proposed thesis work focuses on designing and implementing enhancements to existing experimental devices to enable accurate control of temperature during shearing as well as to achieve control on the applied shear force to conduct shear creep experiments. The work is necessary in order to carry out a experimental campaign to enrich the available dataset by means of systematic testing of selected clayey soils under various stress and thermal conditions, and to provide a preliminary empirical interpretation.
- assigned and confirmed by the Study Dept.