Prof. D. N. Singh

SHETTY RAKSHITH

Indian Institute of Technology Bombay, Powai, India SHETTYRAKSHITH@GMAIL.COM

INVESTIGATIONS ON RHEOLOGICAL & THERMO-HYDRO-MECHANICAL CHARACTERSITICS OF FINE-GRAINED SOIL SLURRIES

This study aims to provide an insight into the flow- and volume change- characteristics of fine-grained soils in their slurried state, which might be encountered during various natural and/or manmade scenarios such as rainfall-induced terrestrial landslides, offshore landslides, mud-flows, dredging activities, infrastructure projects located in the coastal areas, etc. However, as the test methods and approaches valid in the realm of the conventional soil mechanics, postulated by Terzaghi, cannot be applied to the slurried state of the fine-grained soils, efforts should be made to overcome this situation. Incidentally, such a state of fine-grained soils can be characterized by employing rheological parameters (i.e. yield stress, plastic viscosity, and shear modulus), water content and the pore-fluid characteristics (i.e. salinity). With this in view, investigations were conducted on different types of fine-grained soils and clay minerals in their slurried state, by employing rheometers of different geometries (i) to unveil the mechanism of phase-transition, (ii) to develop generalized relationships between these parameters. In addition, the effect of thermo-mechanical stresses, in particular, the sequential thermo-mechanical stress path that mimics the natural condition during the consolidation of soil slurries, and history of thermal cycle on volume change characteristics of such soils have been investigated extensively. Furthermore, a novel methodology for?Estimation of?Thermally?Induced?Rearrangement of?Soils,?EThIReS, which aids in predicting the excess pore-water pressure developed due to such stresses, has been proposed. The validity of this methodology vis-?-vis experimentally obtained results, from a newly developed setup designated as?TherMecRe, which facilitates simulation of?Thermo-Mechanical?Response of such soils under laboratory conditions, has been established.