Method for calculating unfrozen water content of frozen soil based on ion concentration gradient of clay diffusion layer

Abstract

The invention relates to a method for calculating the unfrozen water content of frozen soil based on the ion concentration gradient of a clay diffusion layer. The method comprises the steps of (1) collecting a soil sample, measuring the particle size distribution of the soil and the humidity at normal temperature, determining the mass percentages of clay, silt and sand in the soil, and taking the measured soil humidity as the initial water content w0; (2) substituting the mass percentages of clay, silt and sand in the soil into a specific surface area estimation model to obtain the specific surface area AS of the soil, wherein the specific surface area estimation model refers to AS = 0.042 + 4.23 Clay% + 1.12 Silt%-1.16 Sand%, and in the formula, Clay%, Silt% and Sand% are the mass percentages of the clay, the silt and the sand respectively; and (3) establishing an unfrozen water content model shown in the description, and calculating the unfrozen water content wu. The method is simple in model expression and accurate in calculation.

Description

technical field [0001] The invention relates to frozen soil engineering, in particular to a method for calculating the unfrozen water content of frozen soil based on the ion concentration gradient of the clay diffusion layer. Background technique [0002] Changes in unfrozen water content affect the freeze-thaw cycle and hydrological cycle of permafrost in cold regions, the water and energy exchange between land and air, vegetation growth, and the structure and strength of permafrost soil. Due to inconvenient transportation and sparsely populated areas in cold regions (such as the Qinghai-Tibet Plateau, Siberia, the Arctic, etc.), it is difficult to obtain unfrozen water data on a wide range of spatial scales and long-term scales by deploying instruments. Therefore, the unfrozen water content calculated by the unfrozen water model is It is the main means of obtaining unfrozen water data in the fields of natural science and cold area engineering. [0003] Since engineers can...

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Problems solved by technology

Therefore, some seemingly simple unfrozen water models are difficult to apply in practice, that is, the input parameters of these models need to be re-run unfrozen water experiments in new locations

In addition, in the range of -1.5~0℃, the error of most semi-empirical unfrozen water models increases significantly

In summary, these factors limit the application of the unfrozen water model in cold regions.

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