[Objective] The infiltration of inorganic salt solutions during dry and wet cycles exerts a significant influence on the structural strength and safety stability of loess masses. The aim of this research is to disclose the impact of inorganic salts on the pore structure and permeability of undisturbed loess under the effect of dry and wet cycles. [Methods] In order to fulfill this research objective, this study centered on the loess from the South Plateau in Jingyang County, Shaanxi Province. By employing laboratory experiments, this study systematically analyzed the variation law of the permeability and pore structure of undisturbed loess under diverse dry and wet cycling conditions and different concentrations of sodium chloride inorganic salt solution, as well as its mechanism of soil and water interaction. [Results] The findings indicated that dry and wet cycles diminished the permeability of undisturbed loess, and the saturated permeability coefficient of undisturbed loess decreased with the increment in the number of dry and wet cycles. The sodium chloride solution augmented the permeability of undisturbed loess, and the enhancement of permeability became more pronounced with the rise in the concentration of the sodium chloride infiltration solution. [Conclusion] Dry and wet cycles facilitated the development of fissures on the surface of undisturbed loess, augmenting the number and area ratio of micropores in the soil, thereby reducing the effective porosity of the soil mass and rendering the soil structure more compact. The infiltration of the sodium chloride solution promoted the dissolution of minerals such as gypsum and rock salt, leading to more developed soil pores and increased permeability. This study enriches the comprehension of the variation law of loess structure and permeability under the combined action of dry and wet cycles and inorganic salt solution infiltration, furnishing scientific support for soil and water conservation and engineering construction in loess regions.
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