A framework for coupled consolidation-desiccation behaviour of clay slurries

Abstract

A framework is proposed to understand coupled consolidation-desiccation in clay slurries using effective stress and soil suction as state variables. Constitutive surfaces were derived from best-fit equations for reference curves where one state variable was kept at 1 kPa and the other was varied up to 106 kPa. Results indicated that volume compressibility comprises of apparent pre-consolidation up to 100 kPa beyond which a single best-fit curve is valid. Similarly, the theoretical virgin compression line (specific gravity dependant), indicated that both state variables have the same effect up to the air entry value (1000 kPa at a void ratio of 1.8) beyond which void ratio reduces more readily under effective stress than under soil suction. Likewise, hydraulic conductivity remained saturated up to the air entry value and varied from 10−9 m/s to 10−12 m/s. Finally, the unsaturated hydraulic conductivity correlated well with empirical relationship up to 10−14 m/s beyond which vapor flow became dominant. Keywords: Clay slurries, Volume compressibility, Hydraulic conductivity, Constitutive surfaces