Investigation to Quantify Suction Characteristics of Marine Soil during Drying and Wetting Cycles

Abstract The water retention characteristics of soil play a significant role in controlling its behavior (viz., strength, volume change, and cracking characteristics) during drying and wetting. In the case of marine soils, the water retention characteristics during drying and wetting cycles depend on both matric suction and osmotic suction. Studies by earlier researchers have mainly focused on soils with low osmotic suction and are applicable to higher degrees of saturation. Furthermore, there is a lack of studies that quantify the hysteresis associated with drying and wetting cycles for marine soils. In this context, the present work attempts the estimation of osmotic suction for marine soil by the experimental measurement of total and matric suction at different stages of drying and wetting by employing Dewpoint PotentiaMeter (WP4C). The study also evaluates hysteresis associated with matric, osmotic, and total suction. It has been observed from the study that osmotic suction has a significant influence on water retention characteristics of marine soils and attains a threshold value for a relatively dry state of the specimen. Furthermore, the hysteresis associated with matric suction is observed to be quite reproducible for different specimens, whereas for osmotic suction, some deviation is observed. The study presents the methodology for experimental quantification of osmotic suction, which would be quite useful in understanding the water retention behavior of marine soils in a more scientific way. It is opined that the findings of the study would be useful for understanding the influence of osmotic suction on marine soil behavior with respect to desiccation cracking during drying and time rate of settlement.