Influence of Drying and Wetting Cycles on SWCCs of Fine-Grained Soils

Abstract

The soil-water characteristics curve (SWCC) is greatly influenced by the path that is followed for suction measurement (i.e., drying or wetting path) and the number of cycles of these paths to which the soil is exposed. To evaluate the influence of these parameters, drying- and wetting-path SWCCs of three fine-grained soils were developed for single and multiple cycles by employing the Aquasorp® Isotherm generator. This device has been primarily employed for food products, powders, and amorphous materials for determination of their moisture sorption isotherm, which relates moisture content to water activity. As water activity can be mathematically related to soil suction, the Aquasorp® can be used for developing the SWCC. Hence, demonstrating the potential of the Aquasorp® for characterizing fine-grained soils becomes essential. The present study has been focused at highlighting the possible uncertainties associated with establishment of the SWCCs (both during drying and wetting paths) and the benefits and limitations of the Aquasorp® in achieving these objectives. Furthermore, by employing mercury intrusion porosimetry (MIP), the significance of capillarity on soil suction, which in turn governs the SWCC, has been demonstrated.

Failure Mechanisms and Protection Measures for Expansive Soil Slopes: A Review

“…This laterally reflects that changes in pore volume in expansive soils can complicate the hysteretic behavior of soils [40,42]. Moreover, expansive soils containing reactive clay minerals exhibit higher hysteresis than other soils [43].…”

Determining the Bimodal Soil–Water Characteristic Curve of Fine-Grained Subgrade Soil Derived from the Compaction Condition by Incorporating Pore Size Distribution

“…The SWCC of a certain soil sample is enveloped by the main wetting and drying curves, and a change in hydraulic path for a certain suction will change the subsequent SWCC to the scanning curves [50,51]. This phenomenon is due to the difference in contact angles between the wetting and drying path, the ink-bottle effect, and the air entrapment in the pores [52][53][54].…”

“…The SWCC of a certain soil sample is enveloped by the main wetting and drying curves, and a change in hydraulic path for a certain suction will change the subsequent SWCC to the scanning curves [50,51]. This phenomenon is due to the difference in contact angles between the wetting and drying path, the ink-bottle effect, and the air entrapment in the pores [52][53][54]. For the unsaturated subgrade soil, the compaction condition determines the initial matric suction and degree of saturation, and subsequent changes in matric suction due to environmental factors are derived from this condition.…”

Novel Techniques to Simulate and Monitor Contaminant–Geomaterial Interactions

“…Earlier studies reveal that these characteristics mainly depend on the mineralogy, water content, dry density and degree of saturation of the soil [123,143]. With this in view, various in situ, laboratory techniques, empirical relationships and pedo-transfer functions (PTFs) have been developed by the researchers to establish soil-water characteristic curve, SWCC [62,158,196,[209][210][211]. However, these techniques are tedious, time-consuming, soil specific, require expensive experimental setups and resort to destructive and invasive techniques for determining soil moisture content [194].…”