Research on the impact of dry-wet cycles on water-holding and strength characteristics of silty clay

By taking silty clay as the research object, we performed direct shear tests and pressure plate tests with varying dry-wet cycles to investigate the impact of these cycles on shear strength and the Soil Water Characteristic Curve (SWCC). Nuclear Magnetic Resonance (NMR) was employed to determine the pore size distribution within the soil, providing insight into the effect of dry-wet cycles on the SWCC and shear strength. The test results indicate that with an increasing number of dry-wet cycles, the sample's saturated volume consistently decreases, the volume change amplitude after drying and saturation continues to decrease, the SWCC of the sample keeps decreasing, along with a reduction in shear strength. Finally, the water-holding model and function fitting were used to fit and compare the test results, and the test results were better extended to the application of engineering numerical calculation.