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Loess in Northwest China is widely deposited atop the Hipparion Red Clay. Unlike red clay stratigraphy, loess is mostly seasonally frozen, with physical properties that change easily at low temperatures, increasing the risk of natural disasters like slope instability and landslides. To study the low-temperature properties of loess and red clay strata, loess-red clay composite samples with varying water contents were subjected to freezing at different low temperatures. Their resistivity and P-wave velocity were measured postfreezing. The results indicate that as water content increases, soil resistivity decreases due to enhanced electrical conduction, with a slower rate of decline. When the temperature decreases, resistivity rises gradually in the unfrozen stage (25 degrees C to - 5 degrees C) and increases rapidly in the frozen stage (-10 degrees C to - 20 degrees C) as water transitions to solid ice. At low water contents, soil resistivity is more sensitive to temperature changes due to reduced liquid conductive pathways. P-wave velocity decreases almost linearly with increasing water content in unfrozen soils, but this trend reverses in frozen soils. With decreasing temperature, P-wave velocity shows minimal change in unfrozen soils but increases significantly after freezing, with greater sensitivity to temperature changes at higher water contents. This experiment provides valuable data support for engineering construction, soil frost heave risk assessment, and geophysical investigations in permafrost regions.

来源平台：BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT