The Role of Stress States on the Hysteric Behavior of Expansive Soil under Multiple Drying-Wetting Cycles

Expansive soils in the field are typically exposed to cyclic wetting and drying due climatic fluctuations subjected a variety of stress conditions nature or when used as compacted layers for construction hydraulic barriers waste disposal facilities. The hysteric behavior soil-water characteristic curve (SWCC) is key parameter understanding, modeling, interpreting unsaturated these under such conditions. This study investigates effect states on hysteresis curves (SWCCs) highly expansive clay over range matric suction between 0 1500 kPa. Two test series were performed, first investigated SWCCs during single drying-wetting (DW) cycle. second studied combined applied multiple cycles SWCC hysteresis. For sake comparison, overall was quantified using average degree terms volumetric water content (ADHθ). Furthermore, contributors observed defined two newly proposed measures; namely, gravimetric (ADHw) volume change (ADHe*). outcomes this indicate that consideration great importance. results show dual trend variation ADHθ with vertical stress. DW induced significant reduction (ADHθ) low- high-stress up certain level cycles, then, no further changes detected. It also found loops low-stress state concentric shape while specimens non-concentric, downward shift increase cycles.